Multiple-Ring Digital Communication Network

NASA Technical Reports Server (NTRS)

Kirkham, Harold

1992-01-01

Optical-fiber digital communication network to support data-acquisition and control functions of electric-power-distribution networks. Optical-fiber links of communication network follow power-distribution routes. Since fiber crosses open power switches, communication network includes multiple interconnected loops with occasional spurs. At each intersection node is needed. Nodes of communication network include power-distribution substations and power-controlling units. In addition to serving data acquisition and control functions, each node acts as repeater, passing on messages to next node(s). Multiple-ring communication network operates on new AbNET protocol and features fiber-optic communication.

Towards Smart Grid Dynamic Ratings

NASA Astrophysics Data System (ADS)

Cheema, Jamal; Clark, Adrian; Kilimnik, Justin; Pavlovski, Chris; Redman, David; Vu, Maria

2011-08-01

The energy distribution industry is giving greater attention to smart grid solutions as a means for increasing the capabilities, efficiency and reliability of the electrical power network. The smart grid makes use of intelligent monitoring and control devices throughout the distribution network to report on electrical properties such as voltage, current and power, as well as raising network alarms and events. A further aspect of the smart grid embodies the dynamic rating of electrical assets of the network. This fundamentally involves a rating of the load current capacity of electrical assets including feeders, transformers and switches. The mainstream approach to rate assets is to apply the vendor plate rating, which often under utilizes assets, or in some cases over utilizes when environmental conditions reduce the effective rated capacity, potentially reducing lifetime. Using active intelligence we have developed a rating system that rates assets in real time based upon several events. This allows for a far more efficient and reliable electrical grid that is able to extend further the life and reliability of the electrical network. In this paper we describe our architecture, the observations made during development and live deployment of the solution into operation. We also illustrate how this solution blends with the smart grid by proposing a dynamic rating system for the smart grid.

Geography and the costs of urban energy infrastructure: The case of electricity and natural gas capital investments

NASA Astrophysics Data System (ADS)

Senyel, Muzeyyen Anil

Investments in the urban energy infrastructure for distributing electricity and natural gas are analyzed using (1) property data measuring distribution plant value at the local/tax district level, and (2) system outputs such as sectoral numbers of customers and energy sales, input prices, company-specific characteristics such as average wages and load factor. Socio-economic and site-specific urban and geographic variables, however, often been neglected in past studies. The purpose of this research is to incorporate these site-specific characteristics of electricity and natural gas distribution into investment cost model estimations. These local characteristics include (1) socio-economic variables, such as income and wealth; (2) urban-related variables, such as density, land-use, street pattern, housing pattern; (3) geographic and environmental variables, such as soil, topography, and weather, and (4) company-specific characteristics such as average wages, and load factor. The classical output variables include residential and commercial-industrial customers and sales. In contrast to most previous research, only capital investments at the local level are considered. In addition to aggregate cost modeling, the analysis focuses on the investment costs for the system components: overhead conductors, underground conductors, conduits, poles, transformers, services, street lighting, and station equipment for electricity distribution; and mains, services, regular and industrial measurement and regulation stations for natural gas distribution. The Box-Cox, log-log and additive models are compared to determine the best fitting cost functions. The Box-Cox form turns out to be superior to the other forms at the aggregate level and for network components. However, a linear additive form provides a better fit for end-user related components. The results show that, in addition to output variables and company-specific variables, various site-specific variables are statistically significant at the aggregate and disaggregate levels. Local electricity and natural gas distribution networks are characterized by a natural monopoly cost structure and economies of scale and density. The results provide evidence for the economies of scale and density for the aggregate electricity and natural gas distribution systems. However, distribution components have varying economic characteristics. The backbones of the networks (overhead conductors for electricity, and mains for natural gas) display economies of scale and density, but services in both systems and street lighting display diseconomies of scale and diseconomies of density. Finally multi-utility network cost analyses are presented for aggregate and disaggregate electricity and natural gas capital investments. Economies of scope analyses investigate whether providing electricity and natural gas jointly is economically advantageous, as compared to providing these products separately. Significant economies of scope are observed for both the total network and the underground capital investments.

Electric Vehicles Charging Scheduling Strategy Considering the Uncertainty of Photovoltaic Output

NASA Astrophysics Data System (ADS)

Wei, Xiangxiang; Su, Su; Yue, Yunli; Wang, Wei; He, Luobin; Li, Hao; Ota, Yutaka

2017-05-01

The rapid development of electric vehicles and distributed generation bring new challenges to security and economic operation of the power system, so the collaborative research of the EVs and the distributed generation have important significance in distribution network. Under this background, an EVs charging scheduling strategy considering the uncertainty of photovoltaic(PV) output is proposed. The characteristics of EVs charging are analysed first. A PV output prediction method is proposed with a PV database then. On this basis, an EVs charging scheduling strategy is proposed with the goal to satisfy EVs users’ charging willingness and decrease the power loss in distribution network. The case study proves that the proposed PV output prediction method can predict the PV output accurately and the EVs charging scheduling strategy can reduce the power loss and stabilize the fluctuation of the load in distributed network.

Control of a solar-energy-supplied electrical-power system without intermediate circuitry

NASA Astrophysics Data System (ADS)

Leistner, K.

A computer control system is developed for electric-power systems comprising solar cells and small numbers of users with individual centrally controlled converters (and storage facilities when needed). Typical system structures are reviewed; the advantages of systems without an intermediate network are outlined; the demands on a control system in such a network (optimizing generator working point and power distribution) are defined; and a flexible modular prototype system is described in detail. A charging station for lead batteries used in electric automobiles is analyzed as an example. The power requirements of the control system (30 W for generator control and 50 W for communications and distribution control) are found to limit its use to larger networks.

Networks: How Energy Links People, Goods and Services, Grades 4, 5. Interdisciplinary Student/Teacher Materials in Energy, the Environment, and the Economy.

ERIC Educational Resources Information Center

Johnson, Bette; Swinton, Olivia

The purpose of this unit is to investigate a simple energy network and to make an analogy with similar mutually supporting networks in the natural and man-made worlds. The lessons in this unit develop the network idea around a simple electrical distribution system that we depend on and also into further consideration of electrical energy itself.…

Interdisciplinary Student/Teacher Materials in Energy, the Environment, and the Economy. Networks: How Energy Links People, Goods and Services, Grades 4, 5.

ERIC Educational Resources Information Center

Johnson, Bette; Swinton, Olivia

The purpose of this unit is to investigate a simple energy network and to make an analogy with similar mutually supporting networks in the natural and man-made worlds. The lessons in this unit develop the network idea around a simple electrical distribution system that we depend on and also into further consideration of electrical energy itself.…

A Petri Net model for distributed energy system

NASA Astrophysics Data System (ADS)

Konopko, Joanna

2015-12-01

Electrical networks need to evolve to become more intelligent, more flexible and less costly. The smart grid is the next generation power energy, uses two-way flows of electricity and information to create a distributed automated energy delivery network. Building a comprehensive smart grid is a challenge for system protection, optimization and energy efficient. Proper modeling and analysis is needed to build an extensive distributed energy system and intelligent electricity infrastructure. In this paper, the whole model of smart grid have been proposed using Generalized Stochastic Petri Nets (GSPN). The simulation of created model is also explored. The simulation of the model has allowed the analysis of how close the behavior of the model is to the usage of the real smart grid.

Voltage management of distribution networks with high penetration of distributed photovoltaic generation sources

NASA Astrophysics Data System (ADS)

Alyami, Saeed

Installation of photovoltaic (PV) units could lead to great challenges to the existing electrical systems. Issues such as voltage rise, protection coordination, islanding detection, harmonics, increased or changed short-circuit levels, etc., need to be carefully addressed before we can see a wide adoption of this environmentally friendly technology. Voltage rise or overvoltage issues are of particular importance to be addressed for deploying more PV systems to distribution networks. This dissertation proposes a comprehensive solution to deal with the voltage violations in distribution networks, from controlling PV power outputs and electricity consumption of smart appliances in real time to optimal placement of PVs at the planning stage. The dissertation is composed of three parts: the literature review, the work that has already been done and the future research tasks. An overview on renewable energy generation and its challenges are given in Chapter 1. The overall literature survey, motivation and the scope of study are also outlined in the chapter. Detailed literature reviews are given in the rest of chapters. The overvoltage and undervoltage phenomena in typical distribution networks with integration of PVs are further explained in Chapter 2. Possible approaches for voltage quality control are also discussed in this chapter, followed by the discussion on the importance of the load management for PHEVs and appliances and its benefits to electric utilities and end users. A new real power capping method is presented in Chapter 3 to prevent overvoltage by adaptively setting the power caps for PV inverters in real time. The proposed method can maintain voltage profiles below a pre-set upper limit while maximizing the PV generation and fairly distributing the real power curtailments among all the PV systems in the network. As a result, each of the PV systems in the network has equal opportunity to generate electricity and shares the responsibility of voltage regulation. The method does not require global information and can be implemented either under a centralized supervisory control scheme or in a distributed way via consensus control. Chapter 4 investigates autonomous operation schedules for three types of intelligent appliances (or residential controllable loads) without receiving external signals for cost saving and for assisting the management of possible photovoltaic generation systems installed in the same distribution network. The three types of controllable loads studied in the chapter are electric water heaters, refrigerators deicing loads, and dishwashers, respectively. Chapter 5 investigates the method to mitigate overvoltage issues at the planning stage. A probabilistic method is presented in the chapter to evaluate the overvoltage risk in a distribution network with different PV capacity sizes under different load levels. Kolmogorov--Smirnov test (K--S test) is used to identify the most proper probability distributions for solar irradiance in different months. To increase accuracy, an iterative process is used to obtain the maximum allowable injection of active power from PVs. Conclusion and discussions on future work are given in Chapter 6.

Topological properties of a self-assembled electrical network via ab initio calculation

NASA Astrophysics Data System (ADS)

Stephenson, C.; Lyon, D.; Hübler, A.

2017-02-01

Interacting electrical conductors self-assemble to form tree like networks in the presence of applied voltages or currents. Experiments have shown that the degree distribution of the steady state networks are identical over a wide range of network sizes. In this work we develop a new model of the self-assembly process starting from the underlying physical interaction between conductors. In agreement with experimental results we find that for steady state networks, our model predicts that the fraction of endpoints is a constant of 0.252, and the fraction of branch points is 0.237. We find that our model predicts that these scaling properties also hold for the network during the approach to the steady state as well. In addition, we also reproduce the experimental distribution of nodes with a given Strahler number for all steady state networks studied.

Analysis and Application of Microgrids

NASA Astrophysics Data System (ADS)

Yue, Lu

New trends of generating electricity locally and utilizing non-conventional or renewable energy sources have attracted increasing interests due to the gradual depletion of conventional fossil fuel energy sources. The new type of power generation is called Distributed Generation (DG) and the energy sources utilized by Distributed Generation are termed Distributed Energy Sources (DERs). With DGs embedded in the distribution networks, they evolve from passive distribution networks to active distribution networks enabling bidirectional power flows in the networks. Further incorporating flexible and intelligent controllers and employing future technologies, active distribution networks will turn to a Microgrid. A Microgrid is a small-scale, low voltage Combined with Heat and Power (CHP) supply network designed to supply electrical and heat loads for a small community. To further implement Microgrids, a sophisticated Microgrid Management System must be integrated. However, due to the fact that a Microgrid has multiple DERs integrated and is likely to be deregulated, the ability to perform real-time OPF and economic dispatch with fast speed advanced communication network is necessary. In this thesis, first, problems such as, power system modelling, power flow solving and power system optimization, are studied. Then, Distributed Generation and Microgrid are studied and reviewed, including a comprehensive review over current distributed generation technologies and Microgrid Management Systems, etc. Finally, a computer-based AC optimization method which minimizes the total transmission loss and generation cost of a Microgrid is proposed and a wireless communication scheme based on synchronized Code Division Multiple Access (sCDMA) is proposed. The algorithm is tested with a 6-bus power system and a 9-bus power system.

A Petri Net model for distributed energy system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konopko, Joanna

2015-12-31

Electrical networks need to evolve to become more intelligent, more flexible and less costly. The smart grid is the next generation power energy, uses two-way flows of electricity and information to create a distributed automated energy delivery network. Building a comprehensive smart grid is a challenge for system protection, optimization and energy efficient. Proper modeling and analysis is needed to build an extensive distributed energy system and intelligent electricity infrastructure. In this paper, the whole model of smart grid have been proposed using Generalized Stochastic Petri Nets (GSPN). The simulation of created model is also explored. The simulation of themore » model has allowed the analysis of how close the behavior of the model is to the usage of the real smart grid.« less

The eGo grid model: An open-source and open-data based synthetic medium-voltage grid model for distribution power supply systems

NASA Astrophysics Data System (ADS)

Amme, J.; Pleßmann, G.; Bühler, J.; Hülk, L.; Kötter, E.; Schwaegerl, P.

2018-02-01

The increasing integration of renewable energy into the electricity supply system creates new challenges for distribution grids. The planning and operation of distribution systems requires appropriate grid models that consider the heterogeneity of existing grids. In this paper, we describe a novel method to generate synthetic medium-voltage (MV) grids, which we applied in our DIstribution Network GeneratOr (DINGO). DINGO is open-source software and uses freely available data. Medium-voltage grid topologies are synthesized based on location and electricity demand in defined demand areas. For this purpose, we use GIS data containing demand areas with high-resolution spatial data on physical properties, land use, energy, and demography. The grid topology is treated as a capacitated vehicle routing problem (CVRP) combined with a local search metaheuristics. We also consider the current planning principles for MV distribution networks, paying special attention to line congestion and voltage limit violations. In the modelling process, we included power flow calculations for validation. The resulting grid model datasets contain 3608 synthetic MV grids in high resolution, covering all of Germany and taking local characteristics into account. We compared the modelled networks with real network data. In terms of number of transformers and total cable length, we conclude that the method presented in this paper generates realistic grids that could be used to implement a cost-optimised electrical energy system.

The impact of electric vehicles on the outlook of future energy system

NASA Astrophysics Data System (ADS)

Zhuk, A.; Buzoverov, E.

2018-02-01

Active promotion of electric vehicles (EVs) and technology of fast EV charging in the medium term may cause significant peak loads on the energy system, what necessitates making strategic decisions related to the development of generating capacities, distribution networks with EV charging infrastructure, and priorities in the development of battery electric vehicles and vehicles with electrochemical generators. The paper analyses one of the most significant aspects of joint development of electric transport system and energy system in the conditions of substantial growth of energy consumption by EVs. The assessments of per-unit-costs of operation and depreciation of EV power unit were made, taking into consideration the expenses of electric power supply. The calculations show that the choice of electricity buffering method for EV fast charging depends on the character of electricity infrastructure in the region where the electric transport is operating. In the conditions of high density of electricity network and a large number of EVs, the stationary storage facilities or the technology of distributed energy storage in EV batteries - vehicle-to-grid (V2G) technology may be used for buffering. In the conditions of low density and low capacity of electricity networks, the most economical solution could be usage of EVs with traction power units based on the combination of air-aluminum electrochemical generator and a buffer battery of small capacity.

Description of a MIL-STD-1553B Data Bus Ada Driver for the LeRC EPS Testbed

NASA Technical Reports Server (NTRS)

Mackin, Michael A.

1995-01-01

This document describes the software designed to provide communication between control computers in the NASA Lewis Research Center Electrical Power System Testbed using MIL-STD-1553B. The software drivers are coded in the Ada programming language and were developed on a MSDOS-based computer workstation. The Electrical Power System (EPS) Testbed is a reduced-scale prototype space station electrical power system. The power system manages and distributes electrical power from the sources (batteries or photovoltaic arrays) to the end-user loads. The electrical system primary operates at 120 volts DC, and the secondary system operates at 28 volts DC. The devices which direct the flow of electrical power are controlled by a network of six control computers. Data and control messages are passed between the computers using the MIL-STD-1553B network. One of the computers, the Power Management Controller (PMC), controls the primary power distribution and another, the Load Management Controller (LMC), controls the secondary power distribution. Each of these computers communicates with two other computers which act as subsidiary controllers. These subsidiary controllers are, in turn, connected to the devices which directly control the flow of electrical power.

Critical behaviour in charging of electric vehicles

NASA Astrophysics Data System (ADS)

Carvalho, Rui; Buzna, Lubos; Gibbens, Richard; Kelly, Frank

2015-09-01

The increasing penetration of electric vehicles over the coming decades, taken together with the high cost to upgrade local distribution networks and consumer demand for home charging, suggest that managing congestion on low voltage networks will be a crucial component of the electric vehicle revolution and the move away from fossil fuels in transportation. Here, we model the max-flow and proportional fairness protocols for the control of congestion caused by a fleet of vehicles charging on two real-world distribution networks. We show that the system undergoes a continuous phase transition to a congested state as a function of the rate of vehicles plugging to the network to charge. We focus on the order parameter and its fluctuations close to the phase transition, and show that the critical point depends on the choice of congestion protocol. Finally, we analyse the inequality in the charging times as the vehicle arrival rate increases, and show that charging times are considerably more equitable in proportional fairness than in max-flow.

Adaptive Energy Forecasting and Information Diffusion for Smart Power Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simmhan, Yogesh; Agarwal, Vaibhav; Aman, Saim

2012-05-16

Smart Power Grids exemplify an emerging class of Cyber Physical Applications that exhibit dynamic, distributed and data intensive (D3) characteristics along with an always-on paradigm to support operational needs. Smart Grids are an outcome of instrumentation, such as Phasor Measurement Units and Smart Power Meters, that is being deployed across the transmission and distribution network of electric grids. These sensors provide utilities with improved situation awareness on near-realtime electricity usage by individual consumers, and the power quality and stability of the transmission network.

Intelligent, self-contained robotic hand

DOEpatents

Krutik, Vitaliy; Doo, Burt; Townsend, William T.; Hauptman, Traveler; Crowell, Adam; Zenowich, Brian; Lawson, John

2007-01-30

A robotic device has a base and at least one finger having at least two links that are connected in series on rotary joints with at least two degrees of freedom. A brushless motor and an associated controller are located at each joint to produce a rotational movement of a link. Wires for electrical power and communication serially connect the controllers in a distributed control network. A network operating controller coordinates the operation of the network, including power distribution. At least one, but more typically two to five, wires interconnect all the controllers through one or more joints. Motor sensors and external world sensors monitor operating parameters of the robotic hand. The electrical signal output of the sensors can be input anywhere on the distributed control network. V-grooves on the robotic hand locate objects precisely and assist in gripping. The hand is sealed, immersible and has electrical connections through the rotary joints for anodizing in a single dunk without masking. In various forms, this intelligent, self-contained, dexterous hand, or combinations of such hands, can perform a wide variety of object gripping and manipulating tasks, as well as locomotion and combinations of locomotion and gripping.

Process for anodizing a robotic device

DOEpatents

Townsend, William T [Weston, MA

2011-11-08

A robotic device has a base and at least one finger having at least two links that are connected in series on rotary joints with at least two degrees of freedom. A brushless motor and an associated controller are located at each joint to produce a rotational movement of a link. Wires for electrical power and communication serially connect the controllers in a distributed control network. A network operating controller coordinates the operation of the network, including power distribution. At least one, but more typically two to five, wires interconnect all the controllers through one or more joints. Motor sensors and external world sensors monitor operating parameters of the robotic hand. The electrical signal output of the sensors can be input anywhere on the distributed control network. V-grooves on the robotic hand locate objects precisely and assist in gripping. The hand is sealed, immersible and has electrical connections through the rotary joints for anodizing in a single dunk without masking. In various forms, this intelligent, self-contained, dexterous hand, or combinations of such hands, can perform a wide variety of object gripping and manipulating tasks, as well as locomotion and combinations of locomotion and gripping.

Value Creation Through Integrated Networks and Convergence

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Martini, Paul; Taft, Jeffrey D.

2015-04-01

Customer adoption of distributed energy resources and public policies are driving changes in the uses of the distribution system. A system originally designed and built for one-way energy flows from central generating facilities to end-use customers is now experiencing injections of energy from customers anywhere on the grid and frequent reversals in the direction of energy flow. In response, regulators and utilities are re-thinking the design and operations of the grid to create more open and transactive electric networks. This evolution has the opportunity to unlock significant value for customers and utilities. Alternatively, failure to seize this potential may insteadmore » lead to an erosion of value if customers seek to defect and disconnect from the system. This paper will discuss how current grid modernization investments may be leveraged to create open networks that increase value through the interaction of intelligent devices on the grid and prosumerization of customers. Moreover, even greater value can be realized through the synergistic effects of convergence of multiple networks. This paper will highlight examples of the emerging nexus of non-electric networks with electricity.« less

Transportation and dynamic networks: Models, theory, and applications to supply chains, electric power, and financial networks

NASA Astrophysics Data System (ADS)

Liu, Zugang

Network systems, including transportation and logistic systems, electric power generation and distribution networks as well as financial networks, provide the critical infrastructure for the functioning of our societies and economies. The understanding of the dynamic behavior of such systems is also crucial to national security and prosperity. The identification of new connections between distinct network systems is the inspiration for the research in this dissertation. In particular, I answer two questions raised by Beckmann, McGuire, and Winsten (1956) and Copeland (1952) over half a century ago, which are, respectively, how are electric power flows related to transportation flows and does money flow like water or electricity? In addition, in this dissertation, I achieve the following: (1) I establish the relationships between transportation networks and three other classes of complex network systems: supply chain networks, electric power generation and transmission networks, and financial networks with intermediation. The establishment of such connections provides novel theoretical insights as well as new pricing mechanisms, and efficient computational methods. (2) I develop new modeling frameworks based on evolutionary variational inequality theory that capture the dynamics of such network systems in terms of the time-varying flows and incurred costs, prices, and, where applicable, profits. This dissertation studies the dynamics of such network systems by addressing both internal competition and/or cooperation, and external changes, such as varying costs and demands. (3) I focus, in depth, on electric power supply chains. By exploiting the relationships between transportation networks and electric power supply chains, I develop a large-scale network model that integrates electric power supply chains and fuel supply markets. The model captures both the economic transactions as well as the physical transmission constraints. The model is then applied to the New England electric power supply chain consisting of 6 states, 5 fuel types, 82 power generators, with a total of 573 generating units, and 10 demand markets. The empirical case study demonstrates that the regional electricity prices simulated by the model match very well the actual electricity prices in New England. I also utilize the model to study interactions between electric power supply chains and energy fuel markets.

Modeling the resilience of critical infrastructure: the role of network dependencies.

PubMed

Guidotti, Roberto; Chmielewski, Hana; Unnikrishnan, Vipin; Gardoni, Paolo; McAllister, Therese; van de Lindt, John

2016-01-01

Water and wastewater network, electric power network, transportation network, communication network, and information technology network are among the critical infrastructure in our communities; their disruption during and after hazard events greatly affects communities' well-being, economic security, social welfare, and public health. In addition, a disruption in one network may cause disruption to other networks and lead to their reduced functionality. This paper presents a unified theoretical methodology for the modeling of dependent/interdependent infrastructure networks and incorporates it in a six-step probabilistic procedure to assess their resilience. Both the methodology and the procedure are general, can be applied to any infrastructure network and hazard, and can model different types of dependencies between networks. As an illustration, the paper models the direct effects of seismic events on the functionality of a potable water distribution network and the cascading effects of the damage of the electric power network (EPN) on the potable water distribution network (WN). The results quantify the loss of functionality and delay in the recovery process due to dependency of the WN on the EPN. The results show the importance of capturing the dependency between networks in modeling the resilience of critical infrastructure.

Modeling the resilience of critical infrastructure: the role of network dependencies

PubMed Central

Guidotti, Roberto; Chmielewski, Hana; Unnikrishnan, Vipin; Gardoni, Paolo; McAllister, Therese; van de Lindt, John

2017-01-01

Water and wastewater network, electric power network, transportation network, communication network, and information technology network are among the critical infrastructure in our communities; their disruption during and after hazard events greatly affects communities’ well-being, economic security, social welfare, and public health. In addition, a disruption in one network may cause disruption to other networks and lead to their reduced functionality. This paper presents a unified theoretical methodology for the modeling of dependent/interdependent infrastructure networks and incorporates it in a six-step probabilistic procedure to assess their resilience. Both the methodology and the procedure are general, can be applied to any infrastructure network and hazard, and can model different types of dependencies between networks. As an illustration, the paper models the direct effects of seismic events on the functionality of a potable water distribution network and the cascading effects of the damage of the electric power network (EPN) on the potable water distribution network (WN). The results quantify the loss of functionality and delay in the recovery process due to dependency of the WN on the EPN. The results show the importance of capturing the dependency between networks in modeling the resilience of critical infrastructure. PMID:28825037

Evaluation and prediction of solar radiation for energy management based on neural networks

NASA Astrophysics Data System (ADS)

Aldoshina, O. V.; Van Tai, Dinh

2017-08-01

Currently, there is a high rate of distribution of renewable energy sources and distributed power generation based on intelligent networks; therefore, meteorological forecasts are particularly useful for planning and managing the energy system in order to increase its overall efficiency and productivity. The application of artificial neural networks (ANN) in the field of photovoltaic energy is presented in this article. Implemented in this study, two periodically repeating dynamic ANS, that are the concentration of the time delay of a neural network (CTDNN) and the non-linear autoregression of a network with exogenous inputs of the NAEI, are used in the development of a model for estimating and daily forecasting of solar radiation. ANN show good productivity, as reliable and accurate models of daily solar radiation are obtained. This allows to successfully predict the photovoltaic output power for this installation. The potential of the proposed method for controlling the energy of the electrical network is shown using the example of the application of the NAEI network for predicting the electric load.

Impact of electric vehicles on the IEEE 34 node distribution infrastructure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Zeming; Shalalfel, Laith; Beshir, Mohammed J.

With the growing penetration of the electric vehicles to our daily life owing to their economic and environmental benefits, there will be both opportunities and challenges to the utilities when adopting plug-in electric vehicles (PEV) to the distribution network. In this study, a thorough analysis based on real-world project is conducted to evaluate the impacts of electric vehicles infrastructure on the grid relating to system load flow, load factor, and voltage stability. IEEE 34 node test feeder was selected and tested along with different case scenarios utilizing the electrical distribution design (EDD) software to find out the potential impacts tomore » the grid.« less

Impact of electric vehicles on the IEEE 34 node distribution infrastructure

DOE PAGES

Jiang, Zeming; Shalalfel, Laith; Beshir, Mohammed J.

2014-10-01

With the growing penetration of the electric vehicles to our daily life owing to their economic and environmental benefits, there will be both opportunities and challenges to the utilities when adopting plug-in electric vehicles (PEV) to the distribution network. In this study, a thorough analysis based on real-world project is conducted to evaluate the impacts of electric vehicles infrastructure on the grid relating to system load flow, load factor, and voltage stability. IEEE 34 node test feeder was selected and tested along with different case scenarios utilizing the electrical distribution design (EDD) software to find out the potential impacts tomore » the grid.« less

Simulation of Electromigration Based on Resistor Networks

NASA Astrophysics Data System (ADS)

Patrinos, Anthony John

A two dimensional computer simulation of electromigration based on resistor networks was designed and implemented. The model utilizes a realistic grain structure generated by the Monte Carlo method and takes specific account of the local effects through which electromigration damage progresses. The dynamic evolution of the simulated thin film is governed by the local current and temperature distributions. The current distribution is calculated by superimposing a two dimensional electrical network on the lattice whose nodes correspond to the particles in the lattice and the branches to interparticle bonds. Current is assumed to flow from site to site via nearest neighbor bonds. The current distribution problem is solved by applying Kirchhoff's rules on the resulting electrical network. The calculation of the temperature distribution in the lattice proceeds by discretizing the partial differential equation for heat conduction, with appropriate material parameters chosen for the lattice and its defects. SEReNe (for Simulation of Electromigration using Resistor Networks) was tested by applying it to common situations arising in experiments with real films with satisfactory results. Specifically, the model successfully reproduces the expected grain size, line width and bamboo effects, the lognormal failure time distribution and the relationship between current density exponent and current density. It has also been modified to simulate temperature ramp experiments but with mixed, in this case, results.

Electricity distribution networks: Changing regulatory approaches

NASA Astrophysics Data System (ADS)

Cambini, Carlo

2016-09-01

Increasing the penetration of distributed generation and smart grid technologies requires substantial investments. A study proposes an innovative approach that combines four regulatory tools to provide economic incentives for distribution system operators to facilitate these innovative practices.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linvill, Carl; Brutkoski, Donna

Mexico's energy reform will have far-reaching effects on how people produce and consume electricity in the country. Market liberalization will open the door to an increasing number of options for Mexican residential, commercial, and industrial consumers, and distributed generation (DG), which for Mexico includes generators of less than 500 kilowatts (kW) of capacity connected to the distribution network. Distributed generation is an option for consumers who want to produce their own electricity and provide electricity services to others. This report seeks to provide guidance to Mexican officials on designing DG economic and regulatory policies.

Percolation dans des reseaux realistes de nanostructures de carbone

NASA Astrophysics Data System (ADS)

Simoneau, Louis-Philippe

Carbon nanotubes have very interesting mechanical and electrical properties for various applications in electronics. They are highly resistant to deformation and can be excellent conductors or semiconductors. However, manipulating individual nanotubes to build structured devices remains very difficult. There is no method for controlling all of the electrical properties, the orientation and the spatial positioning of a large number of nanotubes. The fabrication of disordered networks of nanotubes is much easier, and these systems have a good electrical conductivity which makes them very interesting, especially as materials of transparent and flexible electrodes. There are three main methods of production used to make networks of nanotubes: the solution deposition, the direct growth on substrate and the embedding in a polymer matrix. The solution deposition method can form networks of various densities on a variety of substrates, the direct growth of nanotubes allows the creation of very clean networks on substrates such as SiO2, and the embedding in a polymer matrix can give composite volumes containing varying amounts of nanotubes. Many parameters such as the length of the tubes, their orientation or their tortuosity influence the properties of these networks and the presence of structural disorder complicates the understanding of their interactions. Predicting the properties of a network, such as conductivity, from a few characteristics such as size and density of the tubes can be difficult. This task becomes even more complex if one wants to identify the parameters that will optimize the performance of a device containing the material. We chose to address the carbon nanotube networks problem by developing a series of computer simulation tools that are mainly based on the Monte Carlo method. We take into account a large number of parameters to describe the characteristics of the networks, which allows for a more reliable representation of real networks as well as versatility in the choice of network components that can be simulated. The tools we have developed, grouped together in the RPH-HPN software Reseaux percolatifs hybrides - Hybrid Percolation Networks, construct random networks, detect contact between the tubes, translate the systems to equivalent electrical circuits and calculate global properties. An infinity of networks can have the same basic characteristics (size, diameter, etc.) and therefore the properties of a particular random network are not necessarily representative of the average properties of all networks. To obtain those general properties, we simulate a large number of random networks with the same basic characteristics and the average of the quantities is determined. The network constituent elements can be spheres, rods or snakes. The use of such geometries for network elements makes contact detection simple and quick, and more faithfully reproduce the form of carbon nanotubes. We closely monitor the geometrical and electrical properties of these elements through stochastic distributions of our choice. We can choose the length, diameter, orientation, chirality, tortuosity and impenetrable nature of the elements in order to properly reproduce real networks characteristics. We have considered statistical distribution functions that are rectangular, Gaussian, and Lorentzian, but all other distributions that can be expressed mathematically can also be envisioned. During the creation of a particular network, we generate the elements one by one. Each of their properties is sampled from a preselected distribution. Efficient algorithms used in various fields were adapted to our needs to manage the detection of contacts, clusters and percolation. In addition, we model more realistic contact between rigid nanotubes using an original method used to create the network that does not require a relaxation phase. Finally, we use Kirchhoff's laws to solve the equivalent electrical circuit conventionally. First, we evaluated the impact of a simplification widely used in other nanotube networks simulations studies. Values of the contact resistance at the junction between two nanotubes that are reported in the literature vary over a wide range, while almost all the simulations use a unique value for this parameter. Therefore, we assessed the effect of the presence of various stochastic distributions of contact resistances on the electrical properties of the networks. To do this, we used the experimental results of our collaborators in order to reproduce them by simulation. Our results show that, despite the existence of a wide range of contact resistance values, the nature of the statistical distribution has little impact on the conductivity obtained by simulation. Use of a single value for all connections of a network gives a total conductivity comparable to the experimental conductivity, and similar to that obtained using Gaussian, Lorentzian and uniform rectangular distributions. In fact, the dominant factor is not the type of distribution used to represent the resistance, but the central value of the distribution. Furthermore, we showed by studying bimodal distributions that the presence of lower resistance paths, even in small proportion, can rapidly increase the conductivity of the network. However, the type of stochastic distribution used to sample the spatial orientation of the nanotubes has a significant impact. We observed different behaviors for each of the three forms of distribution of orientation angles that we studied. In each case, a different distribution width maximize the conductivity of the networks. To optimize the conductivity, this distribution width, which is actually the deviation from the main direction, should in general be narrow. The formation of conductive paths is greatly enhanced in the presence of a majority of tubes closely aligned with the conduction direction and a small portion of tubes randomly aligned. The portion of misaligned tubes strongly contributes to the connectivity of nanotubes network by linking several clusters of aligned tubes. In order to increase the realism of our simulations, we also studied the influence of the interpenetrability of nanotubes on the electrical properties of networks. To do this, we describe the nanotubes with mutually impenetrable rigid cores that are surrounded by permeable shells. Thus, by varying the radius of the rigid cores, we have shown that a decrease in the interpenetrability of the nanotubes can increase the conductivity of the networks up to five orders of magnitude. We attribute this increase in conductivity to a greater connectivity of the nanotubes in the network. The more tubes are impenetrable, the more they push back against each other, and the better is the spreading of connected clusters in space. The second parameter on which we focused to improve the realism is the tortuosity of the nanotubes. We investigated the electrical properties of networks where the nanotubes are segmented into ten sections joined end to end. The angle between two consecutive segments is sampled from a uniform rectangular distribution and the variation of the bounds of this distribution allows us to vary the general tortuosity of the network. We observe that the more the tubes are tortuous, the higher the percolation threshold is, and the lower is the total conductivity. This can be nearly two orders of magnitude lower for networks with twisted tubes. We further note that the increase of the percolation threshold is attenuated when the wavy nanotubes have rigid cores. As part of our project, we have developed tools that, to the best of our knowledge, offer the best physical representation of nanotubes in a network of carbon nanotubes to date. This allowed us to study networks of complex geometries and measure the importance of the statistical distributions of parameters in optimizing the conductivity of networks. We have also established that the rigid tube-tube contacts and the nanotube tortuosity have strong impacts on the percolation threshold and conductivity. This work has demonstrated the importance of modeling for the understanding and the adequate description of complex processes, and the development needed to accurately reproduce the behavior of real systems. These tools can now be used to guide the creation of nanotube networks with targeted properties, and also to explore even more complex systems containing for example mixtures of nanotubes and quantum dots.

Co-evolution of electric and telecommunications networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivkin, S.R.

1998-05-01

There are potentially significant societal benefits in co-evolution between electricity and telecommunications in the areas of common infrastructure, accelerated deployment of distributed energy, tighter integration of information flow for energy management and distribution, and improved customer care. With due regard for natural processes that are more potent than any regulation and more real than any ideology, the gains from co-evolution would far outweigh the attenuated and speculative savings from restructuring of electricity that is too simplistic.

Advanced Distribution Management System

NASA Astrophysics Data System (ADS)

Avazov, Artur R.; Sobinova, Liubov A.

2016-02-01

This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

The Local Structure of Globalization. The Network Dynamics of Foreign Direct Investments in the International Electricity Industry

NASA Astrophysics Data System (ADS)

Koskinen, Johan; Lomi, Alessandro

2013-05-01

We study the evolution of the network of foreign direct investment (FDI) in the international electricity industry during the period 1994-2003. We assume that the ties in the network of investment relations between countries are created and deleted in continuous time, according to a conditional Gibbs distribution. This assumption allows us to take simultaneously into account the aggregate predictions of the well-established gravity model of international trade as well as local dependencies between network ties connecting the countries in our sample. According to the modified version of the gravity model that we specify, the probability of observing an investment tie between two countries depends on the mass of the economies involved, their physical distance, and the tendency of the network to self-organize into local configurations of network ties. While the limiting distribution of the data generating process is an exponential random graph model, we do not assume the system to be in equilibrium. We find evidence of the effects of the standard gravity model of international trade on evolution of the global FDI network. However, we also provide evidence of significant dyadic and extra-dyadic dependencies between investment ties that are typically ignored in available research. We show that local dependencies between national electricity industries are sufficient for explaining global properties of the network of foreign direct investments. We also show, however, that network dependencies vary significantly over time giving rise to a time-heterogeneous localized process of network evolution.

District heating and cooling systems for communities through power plant retrofit and distribution networks. Phase 1: identificaion and assessment. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-09-01

Appendix A, Utility Plant Characteristics, contains information describing the characteristics of seven utility plants that were considered during the final site selection process. The plants are: Valley Electric Generating Plant, downtown Milwaukee; Manitowoc Electric Generating Plant, downtown Manitowoc; Blount Street Electric Generating Plant, downtown Madison; Pulliam Electric Generating Plant, downtown Green Bay; Edgewater Electric Generating Plant, downtown Sheboygan; Rock River Electric Generating Plant, near Janesville and Beloit; and Black Hawk Electric Generating Plant, downtown Beloit. Additional appendices are: Future Loads; hvac Inventory; Load Calculations; Factors to Induce Potential Users; Turbine Retrofit/Distribution System Data; and Detailed Economic Analysis Results/Data.

An open data repository for steady state analysis of a 100-node electricity distribution network with moderate connection of renewable energy sources.

PubMed

Lazarou, Stavros; Vita, Vasiliki; Ekonomou, Lambros

2018-02-01

The data of this article represent a real electricity distribution network on twenty kilovolts (20 kV) at medium voltage level of the Hellenic electricity distribution system [1]. This network has been chosen as suitable for smart grid analysis. It demonstrates moderate penetration of renewable sources and it has capability in part of time for reverse power flows. It is suitable for studies of load aggregation, storage, demand response. It represents a rural line of fifty-five kilometres (55 km) total length, a typical length for this type. It serves forty-five (45) medium to low voltage transformers and twenty-four (24) connections to photovoltaic plants. The total installed load capacity is twelve mega-volt-ampere (12 MVA), however the maximum observed load is lower. The data are ready to perform load flow simulation on Matpower [2] for the maximum observed load power on the half production for renewables. The simulation results and processed data for creating the source code are also provided on the database available at http://dx.doi.org/10.7910/DVN/1I6MKU.

Combined effect of CVR and penetration of DG in the voltage profile and losses of lowvoltage secondary distribution networks

NASA Astrophysics Data System (ADS)

Bokhari, Abdullah

Demarcations between traditional distribution power systems and distributed generation (DG) architectures are increasingly evolving as higher DG penetration is introduced in the system. The concerns in existing electric power systems (EPSs) to accommodate less restrictive interconnection policies while maintaining reliability and performance of power delivery have been the major challenge for DG growth. In this dissertation, the work is aimed to study power quality, energy saving and losses in a low voltage distributed network under various DG penetration cases. Simulation platform suite that includes electric power system, distributed generation and ZIP load models is implemented to determine the impact of DGs on power system steady state performance and the voltage profile of the customers/loads in the network under the voltage reduction events. The investigation designed to test the DG impact on power system starting with one type of DG, then moves on multiple DG types distributed in a random case and realistic/balanced case. The functionality of the proposed DG interconnection is designed to meet the basic requirements imposed by the various interconnection standards, most notably IEEE 1547, public service commission, and local utility regulation. It is found that implementation of DGs on the low voltage secondary network would improve customer's voltage profile, system losses and significantly provide energy savings and economics for utilities. In a network populated with DGs, utility would have a uniform voltage profile at the customers end as the voltage profile becomes more concentrated around targeted voltage level. The study further reinforced the concept that the behavior of DG in distributed network would improve voltage regulation as certain percentage reduction on utility side would ensure uniform percentage reduction seen by all customers and reduce number of voltage violations.

A design of wireless sensor networks for a power quality monitoring system.

PubMed

Lim, Yujin; Kim, Hak-Man; Kang, Sanggil

2010-01-01

Power grids deal with the business of generation, transmission, and distribution of electric power. Recently, interest in power quality in electrical distribution systems has increased rapidly. In Korea, the communication network to deliver voltage, current, and temperature measurements gathered from pole transformers to remote monitoring centers employs cellular mobile technology. Due to high cost of the cellular mobile technology, power quality monitoring measurements are limited and data gathering intervals are large. This causes difficulties in providing the power quality monitoring service. To alleviate the problems, in this paper we present a communication infrastructure to provide low cost, reliable data delivery. The communication infrastructure consists of wired connections between substations and monitoring centers, and wireless connections between pole transformers and substations. For the wireless connection, we employ a wireless sensor network and design its corresponding data forwarding protocol to improve the quality of data delivery. For the design, we adopt a tree-based data forwarding protocol in order to customize the distribution pattern of the power quality information. We verify the performance of the proposed data forwarding protocol quantitatively using the NS-2 network simulator.

Power flow analysis and optimal locations of resistive type superconducting fault current limiters.

PubMed

Zhang, Xiuchang; Ruiz, Harold S; Geng, Jianzhao; Shen, Boyang; Fu, Lin; Zhang, Heng; Coombs, Tim A

2016-01-01

Based on conventional approaches for the integration of resistive-type superconducting fault current limiters (SFCLs) on electric distribution networks, SFCL models largely rely on the insertion of a step or exponential resistance that is determined by a predefined quenching time. In this paper, we expand the scope of the aforementioned models by considering the actual behaviour of an SFCL in terms of the temperature dynamic power-law dependence between the electrical field and the current density, characteristic of high temperature superconductors. Our results are compared to the step-resistance models for the sake of discussion and clarity of the conclusions. Both SFCL models were integrated into a power system model built based on the UK power standard, to study the impact of these protection strategies on the performance of the overall electricity network. As a representative renewable energy source, a 90 MVA wind farm was considered for the simulations. Three fault conditions were simulated, and the figures for the fault current reduction predicted by both fault current limiting models have been compared in terms of multiple current measuring points and allocation strategies. Consequently, we have shown that the incorporation of the E - J characteristics and thermal properties of the superconductor at the simulation level of electric power systems, is crucial for estimations of reliability and determining the optimal locations of resistive type SFCLs in distributed power networks. Our results may help decision making by distribution network operators regarding investment and promotion of SFCL technologies, as it is possible to determine the maximum number of SFCLs necessary to protect against different fault conditions at multiple locations.

Regulation of distribution network business

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roman, J.; Gomez, T.; Munoz, A.

1999-04-01

The traditional distribution function actually comprises two separate activities: distribution network and retailing. Retailing, which is also termed supply, consists of trading electricity at the wholesale level and selling it to the end users. The distribution network business, or merely distribution, is a natural monopoly and it must be regulated. Increasing attention is presently being paid to the regulation of distribution pricing. Distribution pricing, comprises two major tasks: global remuneration of the distribution utility and tariff setting by allocation of the total costs among all the users of the network services. In this paper, the basic concepts for establishing themore » global remuneration of a distribution utility are presented. A remuneration scheme which recognizes adequate investment and operation costs, promotes losses reduction and incentivates the control of the quality of service level is proposed. Efficient investment and operation costs are calculated by using different types of strategic planning and regression analysis models. Application examples that have been used during the distribution regulation process in Spain are also presented.« less

Data-Aware Retrodiction for Asynchronous Harmonic Measurement in a Cyber-Physical Energy System.

PubMed

Liu, Youda; Wang, Xue; Liu, Yanchi; Cui, Sujin

2016-08-18

Cyber-physical energy systems provide a networked solution for safety, reliability and efficiency problems in smart grids. On the demand side, the secure and trustworthy energy supply requires real-time supervising and online power quality assessing. Harmonics measurement is necessary in power quality evaluation. However, under the large-scale distributed metering architecture, harmonic measurement faces the out-of-sequence measurement (OOSM) problem, which is the result of latencies in sensing or the communication process and brings deviations in data fusion. This paper depicts a distributed measurement network for large-scale asynchronous harmonic analysis and exploits a nonlinear autoregressive model with exogenous inputs (NARX) network to reorder the out-of-sequence measuring data. The NARX network gets the characteristics of the electrical harmonics from practical data rather than the kinematic equations. Thus, the data-aware network approximates the behavior of the practical electrical parameter with real-time data and improves the retrodiction accuracy. Theoretical analysis demonstrates that the data-aware method maintains a reasonable consumption of computing resources. Experiments on a practical testbed of a cyber-physical system are implemented, and harmonic measurement and analysis accuracy are adopted to evaluate the measuring mechanism under a distributed metering network. Results demonstrate an improvement of the harmonics analysis precision and validate the asynchronous measuring method in cyber-physical energy systems.

Assessment of distributed photovoltair electric-power systems

NASA Astrophysics Data System (ADS)

Neal, R. W.; Deduck, P. F.; Marshall, R. N.

1982-10-01

The development of a methodology to assess the potential impacts of distributed photovoltaic (PV) systems on electric utility systems, including subtransmission and distribution networks, and to apply that methodology to several illustrative examples was developed. The investigations focused upon five specific utilities. Impacts upon utility system operations and generation mix were assessed using accepted utility planning methods in combination with models that simulate PV system performance and life cycle economics. Impacts on the utility subtransmission and distribution systems were also investigated. The economic potential of distributed PV systems was investigated for ownership by the utility as well as by the individual utility customer.

Power Distribution Analysis For Electrical Usage In Province Area Using Olap (Online Analytical Processing)

NASA Astrophysics Data System (ADS)

Samsinar, Riza; Suseno, Jatmiko Endro; Widodo, Catur Edi

2018-02-01

The distribution network is the closest power grid to the customer Electric service providers such as PT. PLN. The dispatching center of power grid companies is also the data center of the power grid where gathers great amount of operating information. The valuable information contained in these data means a lot for power grid operating management. The technique of data warehousing online analytical processing has been used to manage and analysis the great capacity of data. Specific methods for online analytics information systems resulting from data warehouse processing with OLAP are chart and query reporting. The information in the form of chart reporting consists of the load distribution chart based on the repetition of time, distribution chart on the area, the substation region chart and the electric load usage chart. The results of the OLAP process show the development of electric load distribution, as well as the analysis of information on the load of electric power consumption and become an alternative in presenting information related to peak load.

Energy Systems Integration: Demonstrating Distributed Resource Communications

DOE Office of Scientific and Technical Information (OSTI.GOV)

2017-01-01

Overview fact sheet about the Electric Power Research Institute (EPRI) and Schneider Electric Integrated Network Testbed for Energy Grid Research and Technology Experimentation (INTEGRATE) project at the Energy Systems Integration Facility. INTEGRATE is part of the U.S. Department of Energy's Grid Modernization Initiative.

Drive Control Scheme of Electric Power Assisted Wheelchair Based on Neural Network Learning of Human Wheelchair Operation Characteristics

NASA Astrophysics Data System (ADS)

Tanohata, Naoki; Seki, Hirokazu

This paper describes a novel drive control scheme of electric power assisted wheelchairs based on neural network learning of human wheelchair operation characteristics. “Electric power assisted wheelchair” which enhances the drive force of the operator by employing electric motors is expected to be widely used as a mobility support system for elderly and disabled people. However, some handicapped people with paralysis of the muscles of one side of the body cannot maneuver the wheelchair as desired because of the difference in the right and left input force. Therefore, this study proposes a neural network learning system of such human wheelchair operation characteristics and a drive control scheme with variable distribution and assistance ratios. Some driving experiments will be performed to confirm the effectiveness of the proposed control system.

An adequacy-constrained integrated planning method for effective accommodation of DG and electric vehicles in smart distribution systems

NASA Astrophysics Data System (ADS)

Tan, Zhukui; Xie, Baiming; Zhao, Yuanliang; Dou, Jinyue; Yan, Tong; Liu, Bin; Zeng, Ming

2018-06-01

This paper presents a new integrated planning framework for effective accommodating electric vehicles in smart distribution systems (SDS). The proposed method incorporates various investment options available for the utility collectively, including distributed generation (DG), capacitors and network reinforcement. Using a back-propagation algorithm combined with cost-benefit analysis, the optimal network upgrade plan, allocation and sizing of the selected components are determined, with the purpose of minimizing the total system capital and operating costs of DG and EV accommodation. Furthermore, a new iterative reliability test method is proposed. It can check the optimization results by subsequently simulating the reliability level of the planning scheme, and modify the generation reserve margin to guarantee acceptable adequacy levels for each year of the planning horizon. Numerical results based on a 32-bus distribution system verify the effectiveness of the proposed method.

Infrastructure for Integration of Legacy Electrical Equipment into a Smart-Grid Using Wireless Sensor Networks.

PubMed

de Araújo, Paulo Régis C; Filho, Raimir Holanda; Rodrigues, Joel J P C; Oliveira, João P C M; Braga, Stephanie A

2018-04-24

At present, the standardisation of electrical equipment communications is on the rise. In particular, manufacturers are releasing equipment for the smart grid endowed with communication protocols such as DNP3, IEC 61850, and MODBUS. However, there are legacy equipment operating in the electricity distribution network that cannot communicate using any of these protocols. Thus, we propose an infrastructure to allow the integration of legacy electrical equipment to smart grids by using wireless sensor networks (WSNs). In this infrastructure, each legacy electrical device is connected to a sensor node, and the sink node runs a middleware that enables the integration of this device into a smart grid based on suitable communication protocols. This middleware performs tasks such as the translation of messages between the power substation control centre (PSCC) and electrical equipment in the smart grid. Moreover, the infrastructure satisfies certain requirements for communication between the electrical equipment and the PSCC, such as enhanced security, short response time, and automatic configuration. The paper’s contributions include a solution that enables electrical companies to integrate their legacy equipment into smart-grid networks relying on any of the above mentioned communication protocols. This integration will reduce the costs related to the modernisation of power substations.

Infrastructure for Integration of Legacy Electrical Equipment into a Smart-Grid Using Wireless Sensor Networks

PubMed Central

de Araújo, Paulo Régis C.; Filho, Raimir Holanda; Oliveira, João P. C. M.; Braga, Stephanie A.

2018-01-01

At present, the standardisation of electrical equipment communications is on the rise. In particular, manufacturers are releasing equipment for the smart grid endowed with communication protocols such as DNP3, IEC 61850, and MODBUS. However, there are legacy equipment operating in the electricity distribution network that cannot communicate using any of these protocols. Thus, we propose an infrastructure to allow the integration of legacy electrical equipment to smart grids by using wireless sensor networks (WSNs). In this infrastructure, each legacy electrical device is connected to a sensor node, and the sink node runs a middleware that enables the integration of this device into a smart grid based on suitable communication protocols. This middleware performs tasks such as the translation of messages between the power substation control centre (PSCC) and electrical equipment in the smart grid. Moreover, the infrastructure satisfies certain requirements for communication between the electrical equipment and the PSCC, such as enhanced security, short response time, and automatic configuration. The paper’s contributions include a solution that enables electrical companies to integrate their legacy equipment into smart-grid networks relying on any of the above mentioned communication protocols. This integration will reduce the costs related to the modernisation of power substations. PMID:29695099

Advanced Distribution Network Modelling with Distributed Energy Resources

NASA Astrophysics Data System (ADS)

O'Connell, Alison

The addition of new distributed energy resources, such as electric vehicles, photovoltaics, and storage, to low voltage distribution networks means that these networks will undergo major changes in the future. Traditionally, distribution systems would have been a passive part of the wider power system, delivering electricity to the customer and not needing much control or management. However, the introduction of these new technologies may cause unforeseen issues for distribution networks, due to the fact that they were not considered when the networks were originally designed. This thesis examines different types of technologies that may begin to emerge on distribution systems, as well as the resulting challenges that they may impose. Three-phase models of distribution networks are developed and subsequently utilised as test cases. Various management strategies are devised for the purposes of controlling distributed resources from a distribution network perspective. The aim of the management strategies is to mitigate those issues that distributed resources may cause, while also keeping customers' preferences in mind. A rolling optimisation formulation is proposed as an operational tool which can manage distributed resources, while also accounting for the uncertainties that these resources may present. Network sensitivities for a particular feeder are extracted from a three-phase load flow methodology and incorporated into an optimisation. Electric vehicles are the focus of the work, although the method could be applied to other types of resources. The aim is to minimise the cost of electric vehicle charging over a 24-hour time horizon by controlling the charge rates and timings of the vehicles. The results demonstrate the advantage that controlled EV charging can have over an uncontrolled case, as well as the benefits provided by the rolling formulation and updated inputs in terms of cost and energy delivered to customers. Building upon the rolling optimisation, a three-phase optimal power flow method is developed. The formulation has the capability to provide optimal solutions for distribution system control variables, for a chosen objective function, subject to required constraints. It can, therefore, be utilised for numerous technologies and applications. The three-phase optimal power flow is employed to manage various distributed resources, such as photovoltaics and storage, as well as distribution equipment, including tap changers and switches. The flexibility of the methodology allows it to be applied in both an operational and a planning capacity. The three-phase optimal power flow is employed in an operational planning capacity to determine volt-var curves for distributed photovoltaic inverters. The formulation finds optimal reactive power settings for a number of load and solar scenarios and uses these reactive power points to create volt-var curves. Volt-var curves are determined for 10 PV systems on a test feeder. A universal curve is also determined which is applicable to all inverters. The curves are validated by testing them in a power flow setting over a 24-hour test period. The curves are shown to provide advantages to the feeder in terms of reduction of voltage deviations and unbalance, with the individual curves proving to be more effective. It is also shown that adding a new PV system to the feeder only requires analysis for that system. In order to represent the uncertainties that inherently occur on distribution systems, an information gap decision theory method is also proposed and integrated into the three-phase optimal power flow formulation. This allows for robust network decisions to be made using only an initial prediction for what the uncertain parameter will be. The work determines tap and switch settings for a test network with demand being treated as uncertain. The aim is to keep losses below a predefined acceptable value. The results provide the decision maker with the maximum possible variation in demand for a given acceptable variation in the losses. A validation is performed with the resulting tap and switch settings being implemented, and shows that the control decisions provided by the formulation keep losses below the acceptable value while adhering to the limits imposed by the network.

Foundational Report Series: Advanced Distribution Management Systems for Grid Modernization, DMS Integration of Distributed Energy Resources and Microgrids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Ravindra; Reilly, James T.; Wang, Jianhui

Deregulation of the electric utility industry, environmental concerns associated with traditional fossil fuel-based power plants, volatility of electric energy costs, Federal and State regulatory support of “green” energy, and rapid technological developments all support the growth of Distributed Energy Resources (DERs) in electric utility systems and ensure an important role for DERs in the smart grid and other aspects of modern utilities. DERs include distributed generation (DG) systems, such as renewables; controllable loads (also known as demand response); and energy storage systems. This report describes the role of aggregators of DERs in providing optimal services to distribution networks, through DERmore » monitoring and control systems—collectively referred to as a Distributed Energy Resource Management System (DERMS)—and microgrids in various configurations.« less

Noise-sustained synchronization between electrically coupled FitzHugh-Nagumo networks

NASA Astrophysics Data System (ADS)

Cascallares, Guadalupe; Sánchez, Alejandro D.; dell'Erba, Matías G.; Izús, Gonzalo G.

2015-09-01

We investigate the capability of electrical synapses to transmit the noise-sustained network activity from one network to another. The particular setup we consider is two identical rings with excitable FitzHugh-Nagumo cell dynamics and nearest-neighbor antiphase intra-ring coupling, electrically coupled between corresponding nodes. The whole system is submitted to independent local additive Gaussian white noises with common intensity η, but only one ring is externally forced by a global adiabatic subthreshold harmonic signal. We then seek conditions for a particular noise level to promote synchronized stable firing patterns. By running numerical integrations with increasing η, we observe the excitation activity to become spatiotemporally self-organized, until η is so strong that spoils sync between networks for a given value of the electric coupling strength. By means of a four-cell model and calculating the stationary probability distribution, we obtain a (signal-dependent) non-equilibrium potential landscape which explains qualitatively the observed regimes, and whose barrier heights give a good estimate of the optimal noise intensity for the sync between networks.

Advancing Underwater Acoustic Communication for Autonomous Distributed Networks via Sparse Channel Sensing, Coding, and Navigation Support

DTIC Science & Technology

2013-09-30

underwater acoustic communication technologies for autonomous distributed underwater networks, through innovative signal processing, coding, and navigation...in real enviroments , an offshore testbed has been developed to conduct field experimetns. The testbed consists of four nodes and has been deployed...Leadership by the Connecticut Technology Council. Dr. Zhaohui Wang joined the faculty of the Department of Electrical and Computer Engineering at

Network model and short circuit program for the Kennedy Space Center electric power distribution system

NASA Technical Reports Server (NTRS)

1976-01-01

Assumptions made and techniques used in modeling the power network to the 480 volt level are discussed. Basic computational techniques used in the short circuit program are described along with a flow diagram of the program and operational procedures. Procedures for incorporating network changes are included in this user's manual.

Space Station laboratory module power loading analysis

NASA Astrophysics Data System (ADS)

Fu, S. J.

1994-07-01

The electrical power system of Space Station Freedom is an isolated electrical power generation and distribution network designed to meet the demands of a large number of electrical loads. An algorithm is developed to determine the power bus loading status under normal operating conditions to ensure the supply meets demand. The probabilities of power availability for payload operations (experiments) are also derived.

Smart PV grid to reinforce the electrical network

NASA Astrophysics Data System (ADS)

AL-Hamad, Mohamed Y.; Qamber, Isa S.

2017-11-01

Photovoltaic (PV) became the new competitive energy resources of the planet and needs to be engaged in grid to break up the congestion in both Distribution and Transmission systems. The objective of this research is to reduce the load flow through the distribution and transmission equipment by 20%. This reduction will help in relief networks loaded equipment's in all networks. Many projects are starting to develop in the GCC countries and need to be organized to achieve maximum benefits from involving the Renewable Energy Sources (RES) in the network. The GCC countries have a good location for solar energy with high intensity of the solar radiation and clear sky along the year. The opportunities of the solar energy is to utilize and create a sustainable energy resource for this region. Moreover, the target of this research is to engage the PV technology in such a way to lower the over loaded equipment and increases the electricity demand at the consumer's side.

Internal services simulation control in 220/110kV power transformer station Mintia

NASA Astrophysics Data System (ADS)

Ciulica, D.; Rob, R.

2018-01-01

The main objectives in developing the electric transport and distribution networks infrastructure are satisfying the electric energy demand, ensuring the continuity of supply to customers, minimizing electricity losses in the transmission and distribution networks of public interest. This paper presents simulations in functioning of the internal services system 400/230 V ac in the 220/110 kV power transformer station Mintia. Using simulations in Visual Basic, the following premises are taken into consideration. All the ac consumers of the 220/110 kV power transformer station Mintia will be supplied by three 400/230 V transformers for internal services which can mutual reserve. In case of damaging at one transformer, the others are able to assume the entire consumption using automatic release of reserves. The simulation program studies three variants in which the continuity of supply to customers are ensured. As well, by simulations, all the functioning situations are analyzed in detail.

Distribution and Network of Basal Temporal Language Areas: A Study of the Combination of Electric Cortical Stimulation and Diffusion Tensor Imaging.

PubMed

Enatsu, Rei; Kanno, Aya; Ookawa, Satoshi; Ochi, Satoko; Ishiai, Sumio; Nagamine, Takashi; Mikuni, Nobuhiro

2017-10-01

The basal temporal language area (BTLA) is considered to have several functions in language processing; however, its brain network is still unknown. This study investigated the distribution and networks of the BTLA using a combination of electric cortical stimulation and diffusion tensor imaging (DTI). 10 patients with intractable focal epilepsy who underwent presurgical evaluation with subdural electrodes were enrolled in this study (language dominant side: 6 patients, language nondominant side: 4 patients). Electric stimulation at 50 Hz was applied to the electrodes during Japanese sentence reading, morphograms (kanji) reading, and syllabograms (kana) reading tasks to identify the BTLA. DTI was used to identify the subcortical fibers originating from the BTLA found by electric stimulation. The BTLA was found in 6 patients who underwent implantation of the subdural electrodes in the dominant hemisphere. The BTLA was located anywhere between 20 mm and 56 mm posterior to the temporal tips. In 3 patients, electric stimulation of some or all areas within the BTLA induced disturbance in reading of kanji words only. DTI detected the inferior longitudinal fasciculus (ILF) in all patients and the uncinate fasciculus (UF) in 1 patient, originating from the BTLA. ILF was detected from both kanji-specific areas and kanji-nonspecific areas. This study indicates that the network of the BTLA is a part of a ventral stream and is mainly composed of the ILF, which acts as a critical structure for lexical retrieval. ILF is also associated with the specific processing of kanji words. Copyright © 2017 Elsevier Inc. All rights reserved.

Data-Aware Retrodiction for Asynchronous Harmonic Measurement in a Cyber-Physical Energy System

PubMed Central

Liu, Youda; Wang, Xue; Liu, Yanchi; Cui, Sujin

2016-01-01

Cyber-physical energy systems provide a networked solution for safety, reliability and efficiency problems in smart grids. On the demand side, the secure and trustworthy energy supply requires real-time supervising and online power quality assessing. Harmonics measurement is necessary in power quality evaluation. However, under the large-scale distributed metering architecture, harmonic measurement faces the out-of-sequence measurement (OOSM) problem, which is the result of latencies in sensing or the communication process and brings deviations in data fusion. This paper depicts a distributed measurement network for large-scale asynchronous harmonic analysis and exploits a nonlinear autoregressive model with exogenous inputs (NARX) network to reorder the out-of-sequence measuring data. The NARX network gets the characteristics of the electrical harmonics from practical data rather than the kinematic equations. Thus, the data-aware network approximates the behavior of the practical electrical parameter with real-time data and improves the retrodiction accuracy. Theoretical analysis demonstrates that the data-aware method maintains a reasonable consumption of computing resources. Experiments on a practical testbed of a cyber-physical system are implemented, and harmonic measurement and analysis accuracy are adopted to evaluate the measuring mechanism under a distributed metering network. Results demonstrate an improvement of the harmonics analysis precision and validate the asynchronous measuring method in cyber-physical energy systems. PMID:27548171

77 FR 47828 - Amended Notice of Intent To Prepare the Hawai'i Clean Energy Programmatic Environmental Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-10

... efficiency and renewable energy activities and technologies to be analyzed in the PEIS and, accordingly, has... Renewables, (4) Alternative Transportation Fuels and Modes, and (5) Electrical Transmission and Distribution... Kaua'i; electric vehicle public charging networks; efficient appliance rebates; solar water heating...

Islanding detection and over voltage mitigation using wireless sensor networks and electric vehicle charging stations.

DOT National Transportation Integrated Search

2016-06-01

An islanding condition occurs when a distributed generation (DG) unit continues to energize a : part of the grid while said part has been isolated from the main electrical utility. In this event, if : the power of the DG exceeds the load, a transient...

Upscaling of spectral induced polarization response using random tube networks

NASA Astrophysics Data System (ADS)

Maineult, Alexis; Revil, André; Camerlynck, Christian; Florsch, Nicolas; Titov, Konstantin

2017-05-01

In order to upscale the induced polarization (IP) response of porous media, from the pore scale to the sample scale, we implement a procedure to compute the macroscopic complex resistivity response of random tube networks. A network is made of a 2-D square-meshed grid of connected tubes, which obey to a given tube radius distribution. In a simplified approach, the electrical impedance of each tube follows a local Pelton resistivity model, with identical resistivity, chargeability and Cole-Cole exponent values for all the tubes-only the time constant varies, as it depends on the radius of each tube and on a diffusion coefficient also identical for all the tubes. By solving the conservation law for the electrical charge, the macroscopic IP response of the network is obtained. We fit successfully the macroscopic complex resistivity also by a Pelton resistivity model. Simulations on uncorrelated and correlated networks, for which the tube radius distribution is so that the decimal logarithm of the radius is normally distributed, evidence that the local and macroscopic model parameters are the same, except the Cole-Cole exponent: its macroscopic value diminishes with increasing heterogeneity (i.e. with increasing standard deviation of the radius distribution), compared to its local value. The methodology is also applied to six siliciclastic rock samples, for which the pore radius distributions from mercury porosimetry are available. These samples exhibit the same behaviour as synthetic media, that is, the macroscopic Cole-Cole exponent is always lower than the local one. As a conclusion, the pore network method seems to be a promising tool for studying the upscaling of the IP response of porous media.

Detection of Frauds and Other Non-technical Losses in Power Utilities using Smart Meters: A Review

NASA Astrophysics Data System (ADS)

Ahmad, Tanveer; Ul Hasan, Qadeer

2016-06-01

Analysis of losses in power distribution system and techniques to mitigate these are two active areas of research especially in energy scarce countries like Pakistan to increase the availability of power without installing new generation. Since total energy losses account for both technical losses (TL) as well as non-technical losses (NTLs). Utility companies in developing countries are incurring of major financial losses due to non-technical losses. NTLs lead to a series of additional losses, such as damage to the network (infrastructure and the reduction of network reliability) etc. The purpose of this paper is to perform an introductory investigation of non-technical losses in power distribution systems. Additionally, analysis of NTLs using consumer energy consumption data with the help of Linear Regression Analysis has been carried out. This data focuses on the Low Voltage (LV) distribution network, which includes: residential, commercial, agricultural and industrial consumers by using the monthly kWh interval data acquired over a period (one month) of time using smart meters. In this research different prevention techniques are also discussed to prevent illegal use of electricity in the distribution of electrical power system.

Optimal operation management of fuel cell/wind/photovoltaic power sources connected to distribution networks

NASA Astrophysics Data System (ADS)

Niknam, Taher; Kavousifard, Abdollah; Tabatabaei, Sajad; Aghaei, Jamshid

2011-10-01

In this paper a new multiobjective modified honey bee mating optimization (MHBMO) algorithm is presented to investigate the distribution feeder reconfiguration (DFR) problem considering renewable energy sources (RESs) (photovoltaics, fuel cell and wind energy) connected to the distribution network. The objective functions of the problem to be minimized are the electrical active power losses, the voltage deviations, the total electrical energy costs and the total emissions of RESs and substations. During the optimization process, the proposed algorithm finds a set of non-dominated (Pareto) optimal solutions which are stored in an external memory called repository. Since the objective functions investigated are not the same, a fuzzy clustering algorithm is utilized to handle the size of the repository in the specified limits. Moreover, a fuzzy-based decision maker is adopted to select the 'best' compromised solution among the non-dominated optimal solutions of multiobjective optimization problem. In order to see the feasibility and effectiveness of the proposed algorithm, two standard distribution test systems are used as case studies.

Multiobjective assessment of distributed energy storage location in electricity networks

NASA Astrophysics Data System (ADS)

Ribeiro Gonçalves, José António; Neves, Luís Pires; Martins, António Gomes

2017-07-01

This paper presents a methodology to provide information to a decision maker on the associated impacts, both of economic and technical nature, of possible management schemes of storage units for choosing the best location of distributed storage devices, with a multiobjective optimisation approach based on genetic algorithms. The methodology was applied to a case study, a known distribution network model in which the installation of distributed storage units was tested, using lithium-ion batteries. The obtained results show a significant influence of the charging/discharging profile of batteries on the choice of their best location, as well as the relevance that these choices may have for the different network management objectives, for example, for reducing network energy losses or minimising voltage deviations. Results also show a difficult cost-effectiveness of an energy-only service, with the tested systems, both due to capital cost and due to the efficiency of conversion.

Resilient Core Networks for Energy Distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuntze, Nicolai; Rudolph, Carsten; Leivesley, Sally

2014-07-28

Abstract—Substations and their control are crucial for the availability of electricity in today’s energy distribution. Ad- vanced energy grids with Distributed Energy Resources require higher complexity in substations, distributed functionality and communication between devices inside substations and between substations. Also, substations include more and more intelligent devices and ICT based systems. All these devices are connected to other systems by different types of communication links or are situated in uncontrolled environments. Therefore, the risk of ICT based attacks on energy grids is growing. Consequently, security measures to counter these risks need to be an intrinsic part of energy grids. Thismore » paper introduces the concept of a Resilient Core Network to interconnected substations. This core network provides essen- tial security features, enables fast detection of attacks and allows for a distributed and autonomous mitigation of ICT based risks.« less

Investigation of transient overvoltages in heavily meshed low-voltage underground distribution networks

NASA Astrophysics Data System (ADS)

Salcedo Ulerio, Reynaldo Odalis

The analysis of overvoltages in electrical distribution networks is of considerable significance since they may damage the power system infrastructure and the associated electrical equipment. Overvoltages in distribution networks arise due to switching transients, resonance, lightning strikes and ground faults, among other causes. The operation of network protectors (NWP), low voltage circuit breakers with directional power relay, in a secondary network prevents the continuous flow of reverse power. There are three modes of operation for the network protectors: sensitive, time delayed, and insensitive. In case of a fault, although all of the network protectors sense the fault at the same time, their operation is not simultaneous. Many of them open very quickly with opening times similar to those of the feeder breaker. However, some operate a few cycles later, others take several seconds to open and a few might even fail to operate. Therefore, depending on the settings of the network protectors, faults can last for significantly long time due to backfeeding of current from the low voltage (LV) network into the medium voltage (MV) network. In this work, low voltages are defined as 208V/460V and medium voltage are defined as 25kV/35kV. This thesis presents overvoltages which arise because of the occurrence of a single-line-to-ground (SLG) fault on the MV side (connected in delta) of the system. The thesis reveals that overvoltage stresses are imposed on insulation, micro-processor controlled equipment, and switching devices by overvoltages during current backfeeding. Also, it establishes a relationship between overvoltage magnitude, its duration, and the network loading conditions. Overvoltages above 3 p.u. may be developed as a result of a simultaneous occurrence of three phenomena: neutral displacement, Ferranti effect, and magnetic current chopping. Furthermore, this thesis exposes the possibility of occurrence of the ferro-resonance phenomena in a distribution network having secondary grid, making the study of extreme importance especially in the case of a misoperating network protector. The test systems for both studies were designed following the conventional distribution network with secondary grid, similar to those in the New York City Area. Simulations were performed using the electro-magnetic transient program revised version (EMTP-RV) considering detailed representation of system components as well as the non-linear magnetization and losses of transformers.

Trans-oceanic Remote Power Hardware-in-the-Loop: Multi-site Hardware, Integrated Controller, and Electric Network Co-simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lundstrom, Blake R.; Palmintier, Bryan S.; Rowe, Daniel

Electric system operators are increasingly concerned with the potential system-wide impacts of the large-scale integration of distributed energy resources (DERs) including voltage control, protection coordination, and equipment wear. This prompts a need for new simulation techniques that can simultaneously capture all the components of these large integrated smart grid systems. This paper describes a novel platform that combines three emerging research areas: power systems co-simulation, power hardware in the loop (PHIL) simulation, and lab-lab links. The platform is distributed, real-time capable, allows for easy internet-based connection from geographically-dispersed participants, and is software platform agnostic. We demonstrate its utility by studyingmore » real-time PHIL co-simulation of coordinated solar PV firming control of two inverters connected in multiple electric distribution network models, prototypical of U.S. and Australian systems. Here, the novel trans-pacific closed-loop system simulation was conducted in real-time using a power network simulator and physical PV/battery inverter at power at the National Renewable Energy Laboratory in Golden, CO, USA and a physical PV inverter at power at the Commonwealth Scientific and Industrial Research Organisation's Energy Centre in Newcastle, NSW, Australia. This capability enables smart grid researchers throughout the world to leverage their unique simulation capabilities for multi-site collaborations that can effectively simulate and validate emerging smart grid technology solutions.« less

Trans-oceanic Remote Power Hardware-in-the-Loop: Multi-site Hardware, Integrated Controller, and Electric Network Co-simulation

DOE PAGES

Lundstrom, Blake R.; Palmintier, Bryan S.; Rowe, Daniel; ...

2017-07-24

Electric system operators are increasingly concerned with the potential system-wide impacts of the large-scale integration of distributed energy resources (DERs) including voltage control, protection coordination, and equipment wear. This prompts a need for new simulation techniques that can simultaneously capture all the components of these large integrated smart grid systems. This paper describes a novel platform that combines three emerging research areas: power systems co-simulation, power hardware in the loop (PHIL) simulation, and lab-lab links. The platform is distributed, real-time capable, allows for easy internet-based connection from geographically-dispersed participants, and is software platform agnostic. We demonstrate its utility by studyingmore » real-time PHIL co-simulation of coordinated solar PV firming control of two inverters connected in multiple electric distribution network models, prototypical of U.S. and Australian systems. Here, the novel trans-pacific closed-loop system simulation was conducted in real-time using a power network simulator and physical PV/battery inverter at power at the National Renewable Energy Laboratory in Golden, CO, USA and a physical PV inverter at power at the Commonwealth Scientific and Industrial Research Organisation's Energy Centre in Newcastle, NSW, Australia. This capability enables smart grid researchers throughout the world to leverage their unique simulation capabilities for multi-site collaborations that can effectively simulate and validate emerging smart grid technology solutions.« less

Electrical localization of weakly electric fish using neural networks

NASA Astrophysics Data System (ADS)

Kiar, Greg; Mamatjan, Yasin; Jun, James; Maler, Len; Adler, Andy

2013-04-01

Weakly Electric Fish (WEF) emit an Electric Organ Discharge (EOD), which travels through the surrounding water and enables WEF to locate nearby objects or to communicate between individuals. Previous tracking of WEF has been conducted using infrared (IR) cameras and subsequent image processing. The limitation of visual tracking is its relatively low frame-rate and lack of reliability when visually obstructed. Thus, there is a need for reliable monitoring of WEF location and behaviour. The objective of this study is to provide an alternative and non-invasive means of tracking WEF in real-time using neural networks (NN). This study was carried out in three stages. First stage was to recreate voltage distributions by simulating the WEF using EIDORS and finite element method (FEM) modelling. Second stage was to validate the model using phantom data acquired from an Electrical Impedance Tomography (EIT) based system, including a phantom fish and tank. In the third stage, the measurement data was acquired using a restrained WEF within a tank. We trained the NN based on the voltage distributions for different locations of the WEF. With networks trained on the acquired data, we tracked new locations of the WEF and observed the movement patterns. The results showed a strong correlation between expected and calculated values of WEF position in one dimension, yielding a high spatial resolution within 1 cm and 10 times higher temporal resolution than IR cameras. Thus, the developed approach could be used as a practical method to non-invasively monitor the WEF in real-time.

Information Theoretically Secure, Enhanced Johnson Noise Based Key Distribution over the Smart Grid with Switched Filters

PubMed Central

2013-01-01

We introduce a protocol with a reconfigurable filter system to create non-overlapping single loops in the smart power grid for the realization of the Kirchhoff-Law-Johnson-(like)-Noise secure key distribution system. The protocol is valid for one-dimensional radial networks (chain-like power line) which are typical of the electricity distribution network between the utility and the customer. The speed of the protocol (the number of steps needed) versus grid size is analyzed. When properly generalized, such a system has the potential to achieve unconditionally secure key distribution over the smart power grid of arbitrary geometrical dimensions. PMID:23936164

Information theoretically secure, enhanced Johnson noise based key distribution over the smart grid with switched filters.

PubMed

Gonzalez, Elias; Kish, Laszlo B; Balog, Robert S; Enjeti, Prasad

2013-01-01

We introduce a protocol with a reconfigurable filter system to create non-overlapping single loops in the smart power grid for the realization of the Kirchhoff-Law-Johnson-(like)-Noise secure key distribution system. The protocol is valid for one-dimensional radial networks (chain-like power line) which are typical of the electricity distribution network between the utility and the customer. The speed of the protocol (the number of steps needed) versus grid size is analyzed. When properly generalized, such a system has the potential to achieve unconditionally secure key distribution over the smart power grid of arbitrary geometrical dimensions.

How large customer direct power transaction mode give consideration to power generation cleaning and power saving

NASA Astrophysics Data System (ADS)

Liu, Yu; Zeng, Ming; Liu, Wei; Li, Ran

2017-05-01

The so-called Large Customers' Direct Power Transaction, refers to the mode that the users on high voltage level, or being seized of hold the large power or independent power distribution, have the qualification of purchasing electricity directly from the generation companies and pay reasonable electricity transmission and distribution fee to the power network enterprises because the transaction is through its transmission channel. The Direct Purchase promotes the marketization level of electricity trading, but there are some problems in its developing process, especially whether promotes the green optimal allocation of power resources, this paper aims to explore the solution.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trinklei, Eddy; Parker, Gordon; Weaver, Wayne

This report presents a scoping study for networked microgrids which are defined as "Interoperable groups of multiple Advanced Microgrids that become an integral part of the electricity grid while providing enhanced resiliency through self-healing, aggregated ancillary services, and real-time communication." They result in optimal electrical system configurations and controls whether grid-connected or in islanded modes and enable high penetrations of distributed and renewable energy resources. The vision for the purpose of this document is: "Networked microgrids seamlessly integrate with the electricity grid or other Electric Power Sources (EPS) providing cost effective, high quality, reliable, resilient, self-healing power delivery systems." Scopingmore » Study: Networked Microgrids September 4, 2014 Eddy Trinklein, Michigan Technological University Gordon Parker, Michigan Technological University Wayne Weaver, Michigan Technological University Rush Robinett, Michigan Technological University Lucia Gauchia Babe, Michigan Technological University Chee-Wooi Ten, Michigan Technological University Ward Bower, Ward Bower Innovations LLC Steve Glover, Sandia National Laboratories Steve Bukowski, Sandia National Laboratories Prepared by Michigan Technological University Houghton, Michigan 49931 Michigan Technological University« less

Artificial neural network application for space station power system fault diagnosis

NASA Technical Reports Server (NTRS)

Momoh, James A.; Oliver, Walter E.; Dias, Lakshman G.

1995-01-01

This study presents a methodology for fault diagnosis using a Two-Stage Artificial Neural Network Clustering Algorithm. Previously, SPICE models of a 5-bus DC power distribution system with assumed constant output power during contingencies from the DDCU were used to evaluate the ANN's fault diagnosis capabilities. This on-going study uses EMTP models of the components (distribution lines, SPDU, TPDU, loads) and power sources (DDCU) of Space Station Alpha's electrical Power Distribution System as a basis for the ANN fault diagnostic tool. The results from the two studies are contrasted. In the event of a major fault, ground controllers need the ability to identify the type of fault, isolate the fault to the orbital replaceable unit level and provide the necessary information for the power management expert system to optimally determine a degraded-mode load schedule. To accomplish these goals, the electrical power distribution system's architecture can be subdivided into three major classes: DC-DC converter to loads, DC Switching Unit (DCSU) to Main bus Switching Unit (MBSU), and Power Sources to DCSU. Each class which has its own electrical characteristics and operations, requires a unique fault analysis philosophy. This study identifies these philosophies as Riddles 1, 2 and 3 respectively. The results of the on-going study addresses Riddle-1. It is concluded in this study that the combination of the EMTP models of the DDCU, distribution cables and electrical loads yields a more accurate model of the behavior and in addition yielded more accurate fault diagnosis using ANN versus the results obtained with the SPICE models.

Monitoring and control requirement definition study for Dispersed Storage and Generation (DSG). Volume 4, appendix C: Identification from utility visits of present and future approaches to integration of DSG into distribution networks

NASA Technical Reports Server (NTRS)

1980-01-01

Visits to four utilities concerned with the use of DSG power sources on their distribution networks yielded useful impressions of present and future approaches to the integration of DSGs into electrical distribution network. Different approaches to future utility systems with DSG are beginning to take shape. The new DSG sources will be in decentralized locations with some measure of centralized control. The utilities have yet to establish firmly the communication and control means or their organization. For the present, the means for integrating the DSGs and their associated monitoring and control equipment into a unified system have not been decided.

Confining the angular distribution of terrestrial gamma ray flash emission

NASA Astrophysics Data System (ADS)

Gjesteland, T.; Østgaard, N.; Collier, A. B.; Carlson, B. E.; Cohen, M. B.; Lehtinen, N. G.

2011-11-01

Terrestrial gamma ray flashes (TGFs) are bremsstrahlung emissions from relativistic electrons accelerated in electric fields associated with thunder storms, with photon energies up to at least 40 MeV, which sets the lowest estimate of the total potential of 40 MV. The electric field that produces TGFs will be reflected by the initial angular distribution of the TGF emission. Here we present the first constraints on the TGF emission cone based on accurately geolocated TGFs. The source lightning discharges associated with TGFs detected by RHESSI are determined from the Atmospheric Weather Electromagnetic System for Observation, Modeling, and Education (AWESOME) network and the World Wide Lightning Location Network (WWLLN). The distribution of the observation angles for 106 TGFs are compared to Monte Carlo simulations. We find that TGF emissions within a half angle >30° are consistent with the distributions of observation angle derived from the networks. In addition, 36 events occurring before 2006 are used for spectral analysis. The energy spectra are binned according to observation angle. The result is a significant softening of the TGF energy spectrum for large (>40°) observation angles, which is consistent with a TGF emission half angle (<40°). The softening is due to Compton scattering which reduces the photon energies.

Degradable transportation network with the addition of electric vehicles: Network equilibrium analysis

PubMed Central

Zhang, Rui; Yao, Enjian; Yang, Yang

2017-01-01

Introducing electric vehicles (EVs) into urban transportation network brings higher requirement on travel time reliability and charging reliability. Specifically, it is believed that travel time reliability is a key factor influencing travelers’ route choice. Meanwhile, due to the limited cruising range, EV drivers need to better learn about the required energy for the whole trip to make decisions about whether charging or not and where to charge (i.e., charging reliability). Since EV energy consumption is highly related to travel speed, network uncertainty affects travel time and charging demand estimation significantly. Considering the network uncertainty resulted from link degradation, which influences the distribution of travel demand on transportation network and the energy demand on power network, this paper aims to develop a reliability-based network equilibrium framework for accommodating degradable road conditions with the addition of EVs. First, based on the link travel time distribution, the mean and variance of route travel time and monetary expenses related to energy consumption are deduced, respectively. And the charging time distribution of EVs with charging demand is also estimated. Then, a nested structure is considered to deal with the difference of route choice behavior derived by the different uncertainty degrees between the routes with and without degradable links. Given the expected generalized travel cost and a psychological safety margin, a traffic assignment model with the addition of EVs is formulated. Subsequently, a heuristic solution algorithm is developed to solve the proposed model. Finally, the effects of travelers’ risk attitude, network degradation degree, and EV penetration rate on network performance are illustrated through an example network. The numerical results show that the difference of travelers’ risk attitudes does have impact on the route choice, and the widespread adoption of EVs can cut down the total system travel cost effectively when the transportation network is more reliable. PMID:28886167

Degradable transportation network with the addition of electric vehicles: Network equilibrium analysis.

PubMed

Zhang, Rui; Yao, Enjian; Yang, Yang

2017-01-01

Introducing electric vehicles (EVs) into urban transportation network brings higher requirement on travel time reliability and charging reliability. Specifically, it is believed that travel time reliability is a key factor influencing travelers' route choice. Meanwhile, due to the limited cruising range, EV drivers need to better learn about the required energy for the whole trip to make decisions about whether charging or not and where to charge (i.e., charging reliability). Since EV energy consumption is highly related to travel speed, network uncertainty affects travel time and charging demand estimation significantly. Considering the network uncertainty resulted from link degradation, which influences the distribution of travel demand on transportation network and the energy demand on power network, this paper aims to develop a reliability-based network equilibrium framework for accommodating degradable road conditions with the addition of EVs. First, based on the link travel time distribution, the mean and variance of route travel time and monetary expenses related to energy consumption are deduced, respectively. And the charging time distribution of EVs with charging demand is also estimated. Then, a nested structure is considered to deal with the difference of route choice behavior derived by the different uncertainty degrees between the routes with and without degradable links. Given the expected generalized travel cost and a psychological safety margin, a traffic assignment model with the addition of EVs is formulated. Subsequently, a heuristic solution algorithm is developed to solve the proposed model. Finally, the effects of travelers' risk attitude, network degradation degree, and EV penetration rate on network performance are illustrated through an example network. The numerical results show that the difference of travelers' risk attitudes does have impact on the route choice, and the widespread adoption of EVs can cut down the total system travel cost effectively when the transportation network is more reliable.

Automated Power-Distribution System

NASA Technical Reports Server (NTRS)

Thomason, Cindy; Anderson, Paul M.; Martin, James A.

1990-01-01

Automated power-distribution system monitors and controls electrical power to modules in network. Handles both 208-V, 20-kHz single-phase alternating current and 120- to 150-V direct current. Power distributed to load modules from power-distribution control units (PDCU's) via subsystem distributors. Ring busses carry power to PDCU's from power source. Needs minimal attention. Detects faults and also protects against them. Potential applications include autonomous land vehicles and automated industrial process systems.

Intelligent Distribution Voltage Control with Distributed Generation =

NASA Astrophysics Data System (ADS)

Castro Mendieta, Jose

In this thesis, three methods for the optimal participation of the reactive power of distributed generations (DGs) in unbalanced distributed network have been proposed, developed, and tested. These new methods were developed with the objectives of maintain voltage within permissible limits and reduce losses. The first method proposes an optimal participation of reactive power of all devices available in the network. The propose approach is validated by comparing the results with other methods reported in the literature. The proposed method was implemented using Simulink of Matlab and OpenDSS. Optimization techniques and the presentation of results are from Matlab. The co-simulation of Electric Power Research Institute's (EPRI) OpenDSS program solves a three-phase optimal power flow problem in the unbalanced IEEE 13 and 34-node test feeders. The results from this work showed a better loss reduction compared to the Coordinated Voltage Control (CVC) method. The second method aims to minimize the voltage variation on the pilot bus on distribution network using DGs. It uses Pareto and Fuzzy-PID logic to reduce the voltage variation. Results indicate that the proposed method reduces the voltage variation more than the other methods. Simulink of Matlab and OpenDSS is used in the development of the proposed approach. The performance of the method is evaluated on IEEE 13-node test feeder with one and three DGs. Variables and unbalanced loads are used, based on real consumption data, over a time window of 48 hours. The third method aims to minimize the reactive losses using DGs on distribution networks. This method analyzes the problem using the IEEE 13-node test feeder with three different loads and the IEEE 123-node test feeder with four DGs. The DGs can be fixed or variables. Results indicate that integration of DGs to optimize the reactive power of the network helps to maintain the voltage within the allowed limits and to reduce the reactive power losses. The thesis is presented in the form of the three articles. The first article is published in the journal Electrical Power and Energy System, the second is published in the international journal Energies and the third was submitted to the journal Electrical Power and Energy System. Two other articles have been published in conferences with reviewing committee. This work is based on six chapters, which are detailed in the various sections of the thesis.

Electric field mill network products to improve detection of the lightning hazard

NASA Technical Reports Server (NTRS)

Maier, Launa M.

1987-01-01

An electric field mill network has been used at Kennedy Space Center for over 10 years as part of the thunderstorm detection system. Several algorithms are currently available to improve the informational output of the electric field mill data. The charge distributions of roughly 50 percent of all lightning can be modeled as if they reduced the charged cloud by a point charge or a point dipole. Using these models, the spatial differences in the lightning induced electric field changes, and a least squares algorithm to obtain an optimum solution, the three-dimensional locations of the lightning charge centers can be located. During the lifetime of a thunderstorm, dynamically induced charging, modeled as a current source, can be located spatially with measurements of Maxwell current density. The electric field mills can be used to calculate the Maxwell current density at times when it is equal to the displacement current density. These improvements will produce more accurate assessments of the potential electrical activity, identify active cells, and forecast thunderstorm termination.

Intelligent decision support algorithm for distribution system restoration.

PubMed

Singh, Reetu; Mehfuz, Shabana; Kumar, Parmod

2016-01-01

Distribution system is the means of revenue for electric utility. It needs to be restored at the earliest if any feeder or complete system is tripped out due to fault or any other cause. Further, uncertainty of the loads, result in variations in the distribution network's parameters. Thus, an intelligent algorithm incorporating hybrid fuzzy-grey relation, which can take into account the uncertainties and compare the sequences is discussed to analyse and restore the distribution system. The simulation studies are carried out to show the utility of the method by ranking the restoration plans for a typical distribution system. This algorithm also meets the smart grid requirements in terms of an automated restoration plan for the partial/full blackout of network.

Simulation of a Lunar Surface Base Power Distribution Network for the Constellation Lunar Surface Systems

NASA Technical Reports Server (NTRS)

Mintz, Toby; Maslowski, Edward A.; Colozza, Anthony; McFarland, Willard; Prokopius, Kevin P.; George, Patrick J.; Hussey, Sam W.

2010-01-01

The Lunar Surface Power Distribution Network Study team worked to define, breadboard, build and test an electrical power distribution system consistent with NASA's goal of providing electrical power to sustain life and power equipment used to explore the lunar surface. A testbed was set up to simulate the connection of different power sources and loads together to form a mini-grid and gain an understanding of how the power systems would interact. Within the power distribution scheme, each power source contributes to the grid in an independent manner without communication among the power sources and without a master-slave scenario. The grid consisted of four separate power sources and the accompanying power conditioning equipment. Overall system design and testing was performed. The tests were performed to observe the output and interaction of the different power sources as some sources are added and others are removed from the grid connection. The loads on the system were also varied from no load to maximum load to observe the power source interactions.

Application of high performance asynchronous socket communication in power distribution automation

NASA Astrophysics Data System (ADS)

Wang, Ziyu

2017-05-01

With the development of information technology and Internet technology, and the growing demand for electricity, the stability and the reliable operation of power system have been the goal of power grid workers. With the advent of the era of big data, the power data will gradually become an important breakthrough to guarantee the safe and reliable operation of the power grid. So, in the electric power industry, how to efficiently and robustly receive the data transmitted by the data acquisition device, make the power distribution automation system be able to execute scientific decision quickly, which is the pursuit direction in power grid. In this paper, some existing problems in the power system communication are analysed, and with the help of the network technology, a set of solutions called Asynchronous Socket Technology to the problem in network communication which meets the high concurrency and the high throughput is proposed. Besides, the paper also looks forward to the development direction of power distribution automation in the era of big data and artificial intelligence.

A Scalable Distribution Network Risk Evaluation Framework via Symbolic Dynamics

PubMed Central

Yuan, Kai; Liu, Jian; Liu, Kaipei; Tan, Tianyuan

2015-01-01

Background Evaluations of electric power distribution network risks must address the problems of incomplete information and changing dynamics. A risk evaluation framework should be adaptable to a specific situation and an evolving understanding of risk. Methods This study investigates the use of symbolic dynamics to abstract raw data. After introducing symbolic dynamics operators, Kolmogorov-Sinai entropy and Kullback-Leibler relative entropy are used to quantitatively evaluate relationships between risk sub-factors and main factors. For layered risk indicators, where the factors are categorized into four main factors – device, structure, load and special operation – a merging algorithm using operators to calculate the risk factors is discussed. Finally, an example from the Sanya Power Company is given to demonstrate the feasibility of the proposed method. Conclusion Distribution networks are exposed and can be affected by many things. The topology and the operating mode of a distribution network are dynamic, so the faults and their consequences are probabilistic. PMID:25789859

Optical interconnections and networks; Proceedings of the Meeting, The Hague, Netherlands, Mar. 14, 15, 1990

NASA Technical Reports Server (NTRS)

Bartelt, Hartmut (Editor)

1990-01-01

The conference presents papers on interconnections, clock distribution, neural networks, and components and materials. Particular attention is given to a comparison of optical and electrical data interconnections at the board and backplane levels, a wafer-level optical interconnection network layout, an analysis and simulation of photonic switch networks, and the integration of picosecond GaAs photoconductive devices with silicon circuits for optical clocking and interconnects. Consideration is also given to the optical implementation of neural networks, invariance in an optoelectronic implementation of neural networks, and the recording of reversible patterns in polymer lightguides.

An integrated eVoucher mechanism for flexible loads in real-time retail electricity market

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Tao; Pourbabak, Hajir; Liang, Zheming

This study proposes an innovative economic and engineering coupled framework to encourage typical flexible loads or load aggregators, such as parking lots with high penetration of electric vehicles, to participate directly in the real-time retail electricity market based on an integrated eVoucher program. The integrated eVoucher program entails demand side management, either in the positive or negative direction, following a popular customer-centric design principle. It provides the extra economic benefit to end-users and reduces the risk associated with the wholesale electricity market for electric distribution companies (EDCs), meanwhile improving the potential resilience of the distribution networks with consideration for frequencymore » deviations. When implemented, the eVoucher program allows typical flexible loads, such as electric vehicle parking lots, to adjust their demand and consumption behavior according to financial incentives from an EDC. A distribution system operator (DSO) works as a third party to hasten negotiations between such parking lots and EDCs, as well as the price clearing process. Eventually, both electricity retailers and power system operators will benefit from the active participation of the flexible loads and energy customers.« less

An integrated eVoucher mechanism for flexible loads in real-time retail electricity market

DOE PAGES

Chen, Tao; Pourbabak, Hajir; Liang, Zheming; ...

2017-01-26

This study proposes an innovative economic and engineering coupled framework to encourage typical flexible loads or load aggregators, such as parking lots with high penetration of electric vehicles, to participate directly in the real-time retail electricity market based on an integrated eVoucher program. The integrated eVoucher program entails demand side management, either in the positive or negative direction, following a popular customer-centric design principle. It provides the extra economic benefit to end-users and reduces the risk associated with the wholesale electricity market for electric distribution companies (EDCs), meanwhile improving the potential resilience of the distribution networks with consideration for frequencymore » deviations. When implemented, the eVoucher program allows typical flexible loads, such as electric vehicle parking lots, to adjust their demand and consumption behavior according to financial incentives from an EDC. A distribution system operator (DSO) works as a third party to hasten negotiations between such parking lots and EDCs, as well as the price clearing process. Eventually, both electricity retailers and power system operators will benefit from the active participation of the flexible loads and energy customers.« less

Programmability of nanowire networks

NASA Astrophysics Data System (ADS)

Bellew, A. T.; Bell, A. P.; McCarthy, E. K.; Fairfield, J. A.; Boland, J. J.

2014-07-01

Electrical connectivity in networks of nanoscale junctions must be better understood if nanowire devices are to be scaled up from single wires to functional material systems. We show that the natural connectivity behaviour found in random nanowire networks presents a new paradigm for creating multi-functional, programmable materials. In devices made from networks of Ni/NiO core-shell nanowires at different length scales, we discover the emergence of distinct behavioural regimes when networks are electrically stressed. We show that a small network, with few nanowire-nanowire junctions, acts as a unipolar resistive switch, demonstrating very high ON/OFF current ratios (>105). However, large networks of nanowires distribute an applied bias across a large number of junctions, and thus respond not by switching but instead by evolving connectivity. We demonstrate that these emergent properties lead to fault-tolerant materials whose resistance may be tuned, and which are capable of adaptively reconfiguring under stress. By combining these two behavioural regimes, we demonstrate that the same nanowire network may be programmed to act both as a metallic interconnect, and a resistive switch device with high ON/OFF ratio. These results enable the fabrication of programmable, multi-functional materials from random nanowire networks.Electrical connectivity in networks of nanoscale junctions must be better understood if nanowire devices are to be scaled up from single wires to functional material systems. We show that the natural connectivity behaviour found in random nanowire networks presents a new paradigm for creating multi-functional, programmable materials. In devices made from networks of Ni/NiO core-shell nanowires at different length scales, we discover the emergence of distinct behavioural regimes when networks are electrically stressed. We show that a small network, with few nanowire-nanowire junctions, acts as a unipolar resistive switch, demonstrating very high ON/OFF current ratios (>105). However, large networks of nanowires distribute an applied bias across a large number of junctions, and thus respond not by switching but instead by evolving connectivity. We demonstrate that these emergent properties lead to fault-tolerant materials whose resistance may be tuned, and which are capable of adaptively reconfiguring under stress. By combining these two behavioural regimes, we demonstrate that the same nanowire network may be programmed to act both as a metallic interconnect, and a resistive switch device with high ON/OFF ratio. These results enable the fabrication of programmable, multi-functional materials from random nanowire networks. Electronic supplementary information (ESI) available: Nanowire statistics (length, diameter statistics, and oxide thickness) are provided. Forming curves for single junctions and networks. Passive voltage contrast image demonstrating selectivity of conductive pathways in 100 μm network. See DOI: 10.1039/c4nr02338b

Fault detection and classification in electrical power transmission system using artificial neural network.

PubMed

Jamil, Majid; Sharma, Sanjeev Kumar; Singh, Rajveer

2015-01-01

This paper focuses on the detection and classification of the faults on electrical power transmission line using artificial neural networks. The three phase currents and voltages of one end are taken as inputs in the proposed scheme. The feed forward neural network along with back propagation algorithm has been employed for detection and classification of the fault for analysis of each of the three phases involved in the process. A detailed analysis with varying number of hidden layers has been performed to validate the choice of the neural network. The simulation results concluded that the present method based on the neural network is efficient in detecting and classifying the faults on transmission lines with satisfactory performances. The different faults are simulated with different parameters to check the versatility of the method. The proposed method can be extended to the Distribution network of the Power System. The various simulations and analysis of signals is done in the MATLAB(®) environment.

A novel method for energy harvesting simulation based on scenario generation

NASA Astrophysics Data System (ADS)

Wang, Zhe; Li, Taoshen; Xiao, Nan; Ye, Jin; Wu, Min

2018-06-01

Energy harvesting network (EHN) is a new form of computer networks. It converts ambient energy into usable electric energy and supply the electrical energy as a primary or secondary power source to the communication devices. However, most of the EHN uses the analytical probability distribution function to describe the energy harvesting process, which cannot accurately identify the actual situation for the lack of authenticity. We propose an EHN simulation method based on scenario generation in this paper. Firstly, instead of setting a probability distribution in advance, it uses optimal scenario reduction technology to generate representative scenarios in single period based on the historical data of the harvested energy. Secondly, it uses homogeneous simulated annealing algorithm to generate optimal daily energy harvesting scenario sequences to get a more accurate simulation of the random characteristics of the energy harvesting network. Then taking the actual wind power data as an example, the accuracy and stability of the method are verified by comparing with the real data. Finally, we cite an instance to optimize the network throughput, which indicate the feasibility and effectiveness of the method we proposed from the optimal solution and data analysis in energy harvesting simulation.

Electro-actuated hydrogel walkers with dual responsive legs.

PubMed

Morales, Daniel; Palleau, Etienne; Dickey, Michael D; Velev, Orlin D

2014-03-07

Stimuli responsive polyelectrolyte hydrogels may be useful for soft robotics because of their ability to transform chemical energy into mechanical motion without the use of external mechanical input. Composed of soft and biocompatible materials, gel robots can easily bend and fold, interface and manipulate biological components and transport cargo in aqueous solutions. Electrical fields in aqueous solutions offer repeatable and controllable stimuli, which induce actuation by the re-distribution of ions in the system. Electrical fields applied to polyelectrolyte-doped gels submerged in ionic solution distribute the mobile ions asymmetrically to create osmotic pressure differences that swell and deform the gels. The sign of the fixed charges on the polyelectrolyte network determines the direction of bending, which we harness to control the motion of the gel legs in opposing directions as a response to electrical fields. We present and analyze a walking gel actuator comprised of cationic and anionic gel legs made of copolymer networks of acrylamide (AAm)/sodium acrylate (NaAc) and acrylamide/quaternized dimethylaminoethyl methacrylate (DMAEMA Q), respectively. The anionic and cationic legs were attached by electric field-promoted polyion complexation. We characterize the electro-actuated response of the sodium acrylate hydrogel as a function of charge density and external salt concentration. We demonstrate that "osmotically passive" fixed charges play an important role in controlling the bending magnitude of the gel networks. The gel walkers achieve unidirectional motion on flat elastomer substrates and exemplify a simple way to move and manipulate soft matter devices and robots in aqueous solutions.

Design and fabrication of a photovoltaic power system for the Papago Indian village of Schuchuli (Gunsight), Arizona

NASA Technical Reports Server (NTRS)

Bifano, W. J.; Ratajczak, A. F.; Ice, W. J.

1978-01-01

A stand alone photovoltaic power system for installation in the Papago Indian village of Schuchuli is being designed and fabricated to provide electricity for village water pumping and basic domestic needs. The system will consist of a 3.5 kW (peak) photovoltaic array; controls, instrumentations, and storage batteries located in an electrical equipment building and a 120 volt dc village distribution network. The system will power a 2 HP dc electric motor.

Lithographically fabricated gold nanowire waveguides for plasmonic routers and logic gates.

PubMed

Gao, Long; Chen, Li; Wei, Hong; Xu, Hongxing

2018-06-14

Fabricating plasmonic nanowire waveguides and circuits by lithographic fabrication methods is highly desired for nanophotonic circuitry applications. Here we report an approach for fabricating metal nanowire networks by using electron beam lithography and metal film deposition techniques. The gold nanowire structures are fabricated on quartz substrates without using any adhesion layer but coated with a thin layer of Al2O3 film for immobilization. The thermal annealing during the Al2O3 deposition process decreases the surface plasmon loss. In a Y-shaped gold nanowire network, the surface plasmons can be routed to different branches by controlling the polarization of the excitation light, and the routing behavior is dependent on the length of the main nanowire. Simulated electric field distributions show that the zigzag distribution of the electric field in the nanowire network determines the surface plasmon routing. By using two laser beams to excite surface plasmons in a Y-shaped nanowire network, the output intensity can be modulated by the interference of surface plasmons, which can be used to design Boolean logic gates. We experimentally demonstrate that AND, OR, XOR and NOT gates can be realized in three-terminal nanowire networks, and NAND, NOR and XNOR gates can be realized in four-terminal nanowire networks. This work takes a step toward the fabrication of on-chip integrated plasmonic circuits.

Models for the modern power grid

NASA Astrophysics Data System (ADS)

Nardelli, Pedro H. J.; Rubido, Nicolas; Wang, Chengwei; Baptista, Murilo S.; Pomalaza-Raez, Carlos; Cardieri, Paulo; Latva-aho, Matti

2014-10-01

This article reviews different kinds of models for the electric power grid that can be used to understand the modern power system, the smart grid. From the physical network to abstract energy markets, we identify in the literature different aspects that co-determine the spatio-temporal multilayer dynamics of power system. We start our review by showing how the generation, transmission and distribution characteristics of the traditional power grids are already subject to complex behaviour appearing as a result of the the interplay between dynamics of the nodes and topology, namely synchronisation and cascade effects. When dealing with smart grids, the system complexity increases even more: on top of the physical network of power lines and controllable sources of electricity, the modernisation brings information networks, renewable intermittent generation, market liberalisation, prosumers, among other aspects. In this case, we forecast a dynamical co-evolution of the smart grid and other kind of networked systems that cannot be understood isolated. This review compiles recent results that model electric power grids as complex systems, going beyond pure technological aspects. From this perspective, we then indicate possible ways to incorporate the diverse co-evolving systems into the smart grid model using, for example, network theory and multi-agent simulation.

An intelligent switch with back-propagation neural network based hybrid power system

NASA Astrophysics Data System (ADS)

Perdana, R. H. Y.; Fibriana, F.

2018-03-01

The consumption of conventional energy such as fossil fuels plays the critical role in the global warming issues. The carbon dioxide, methane, nitrous oxide, etc. could lead the greenhouse effects and change the climate pattern. In fact, 77% of the electrical energy is generated from fossil fuels combustion. Therefore, it is necessary to use the renewable energy sources for reducing the conventional energy consumption regarding electricity generation. This paper presents an intelligent switch to combine both energy resources, i.e., the solar panels as the renewable energy with the conventional energy from the State Electricity Enterprise (PLN). The artificial intelligence technology with the back-propagation neural network was designed to control the flow of energy that is distributed dynamically based on renewable energy generation. By the continuous monitoring on each load and source, the dynamic pattern of the intelligent switch was better than the conventional switching method. The first experimental results for 60 W solar panels showed the standard deviation of the trial at 0.7 and standard deviation of the experiment at 0.28. The second operation for a 900 W of solar panel obtained the standard deviation of the trial at 0.05 and 0.18 for the standard deviation of the experiment. Moreover, the accuracy reached 83% using this method. By the combination of the back-propagation neural network with the observation of energy usage of the load using wireless sensor network, each load can be evenly distributed and will impact on the reduction of conventional energy usage.

RHYTHMICITY IN THE PROTOPLASMIC STREAMING OF A SLIME MOLD, PHYSARUM POLYCEPHALUM

PubMed Central

Kishimoto, Uichiro

1958-01-01

The electric potential difference (1 to 15 mv.) between two loci of the slime mold connected with a strand of protoplasm changes rhythmically with the same period (60 to 180 seconds) as that of the back and forth protoplasmic streaming along the strand. Generally some phase difference is observed between them. Periods of the electric potential rhythm show a Gaussian distribution. Amplitudes give a somewhat different distribution curve. Wave forms are not always simple harmonic ones, but are distorted more or less. However, auto-correlation analysis proves that there is a dominant rhythm of a nearly constant period which coincides with the mean period of the Gaussian distribution curve. Calculations made on an assumption that the electric potential rhythm is the result of many elementary rhythms (i.e., same periodicity, arbitrary phase angles) distributed throughout the plasmodium, give a satisfactory coincidence with the observed distribution for the amplitude. The predominance of a rhythm of a nearly constant periodicity suggests the existence of well organized interactions among components of a contractile protein network, the rhythmic deformation of which is supposed to be responsible for the protoplasmic streaming and for the electric potential rhythm. PMID:13563808

ESB-based Sensor Web integration for the prediction of electric power supply system vulnerability.

PubMed

Stoimenov, Leonid; Bogdanovic, Milos; Bogdanovic-Dinic, Sanja

2013-08-15

Electric power supply companies increasingly rely on enterprise IT systems to provide them with a comprehensive view of the state of the distribution network. Within a utility-wide network, enterprise IT systems collect data from various metering devices. Such data can be effectively used for the prediction of power supply network vulnerability. The purpose of this paper is to present the Enterprise Service Bus (ESB)-based Sensor Web integration solution that we have developed with the purpose of enabling prediction of power supply network vulnerability, in terms of a prediction of defect probability for a particular network element. We will give an example of its usage and demonstrate our vulnerability prediction model on data collected from two different power supply companies. The proposed solution is an extension of the GinisSense Sensor Web-based architecture for collecting, processing, analyzing, decision making and alerting based on the data received from heterogeneous data sources. In this case, GinisSense has been upgraded to be capable of operating in an ESB environment and combine Sensor Web and GIS technologies to enable prediction of electric power supply system vulnerability. Aside from electrical values, the proposed solution gathers ambient values from additional sensors installed in the existing power supply network infrastructure. GinisSense aggregates gathered data according to an adapted Omnibus data fusion model and applies decision-making logic on the aggregated data. Detected vulnerabilities are visualized to end-users through means of a specialized Web GIS application.

ESB-Based Sensor Web Integration for the Prediction of Electric Power Supply System Vulnerability

PubMed Central

Stoimenov, Leonid; Bogdanovic, Milos; Bogdanovic-Dinic, Sanja

2013-01-01

Electric power supply companies increasingly rely on enterprise IT systems to provide them with a comprehensive view of the state of the distribution network. Within a utility-wide network, enterprise IT systems collect data from various metering devices. Such data can be effectively used for the prediction of power supply network vulnerability. The purpose of this paper is to present the Enterprise Service Bus (ESB)-based Sensor Web integration solution that we have developed with the purpose of enabling prediction of power supply network vulnerability, in terms of a prediction of defect probability for a particular network element. We will give an example of its usage and demonstrate our vulnerability prediction model on data collected from two different power supply companies. The proposed solution is an extension of the GinisSense Sensor Web-based architecture for collecting, processing, analyzing, decision making and alerting based on the data received from heterogeneous data sources. In this case, GinisSense has been upgraded to be capable of operating in an ESB environment and combine Sensor Web and GIS technologies to enable prediction of electric power supply system vulnerability. Aside from electrical values, the proposed solution gathers ambient values from additional sensors installed in the existing power supply network infrastructure. GinisSense aggregates gathered data according to an adapted Omnibus data fusion model and applies decision-making logic on the aggregated data. Detected vulnerabilities are visualized to end-users through means of a specialized Web GIS application. PMID:23955435

The Future of Centrally-Organized Wholesale Electricity Markets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glazer, Craig; Morrison, Jay; Breakman, Paul

The electricity grid in the United States is organized around a network of large, centralized power plants and high voltage transmission lines that transport electricity, sometimes over large distances, before it is delivered to the customer through a local distribution grid. This network of centralized generation and high voltage transmission lines is called the “bulk power system.” Costs relating to bulk power generation typically account for more than half of a customer’s electric bill.1 For this reason, the structure and functioning of wholesale electricity markets have major impacts on costs and economic value for consumers, as well as energy securitymore » and national security. Diverse arrangements for bulk power wholesale markets have evolved over the last several decades. The Southeast and Western United States outside of California have a “bilateral-based” bulk power system where market participants enter into long-term bilateral agreements — using competitive procurements through power marketers, direct arrangements among utilities or with other generation owners, and auctions and exchanges.« less

Passively Damped Laminated Piezoelectric Shell Structures with Integrated Electric Networks

NASA Technical Reports Server (NTRS)

Saravanos, Dimitris A.

1999-01-01

Multi-field mechanics are presented for curvilinear piezoelectric laminates interfaced with distributed passive electric components. The equations of motion for laminated piezoelectric shell structures with embedded passive electric networks are directly formulated and solved using a finite element methodology. The modal damping and frequencies of the piezoelectric shell are calculated from the poles of the system. Experimental and numerical results are presented for the modal damping and frequency of composite beams with a resistively shunted piezoceramic patch. The modal damping and frequency of plates, cylindrical shells and cylindrical composite blades with piezoelectric-resistor layers are predicted. Both analytical and experimental studies illustrate a unique dependence of modal damping and frequencies on the shunting resistance and show the effect of structural shape and curvature on piezoelectric damping.

A compact model for electroosmotic flows in microfluidic devices

NASA Astrophysics Data System (ADS)

Qiao, R.; Aluru, N. R.

2002-09-01

A compact model to compute flow rate and pressure in microfluidic devices is presented. The microfluidic flow can be driven by either an applied electric field or a combined electric field and pressure gradient. A step change in the ζ-potential on a channel wall is treated by a pressure source in the compact model. The pressure source is obtained from the pressure Poisson equation and conservation of mass principle. In the proposed compact model, the complex fluidic network is simplified by an electrical circuit. The compact model can predict the flow rate, pressure distribution and other basic characteristics in microfluidic channels quickly with good accuracy when compared to detailed numerical simulation. Using the compact model, fluidic mixing and dispersion control are studied in a complex microfluidic network.

Energy Production from Biogas: Competitiveness and Support Instruments in Latvia

NASA Astrophysics Data System (ADS)

Klāvs, G.; Kundziņa, A.; Kudrenickis, I.

2016-10-01

Use of renewable energy sources (RES) might be one of the key factors for the triple win-win: improving energy supply security, promoting local economic development, and reducing greenhouse gas emissions. The authors ex-post evaluate the impact of two main support instruments applied in 2010-2014 - the investment support (IS) and the feed-in tariff (FIT) - on the economic viability of small scale (up to 2MWel) biogas unit. The results indicate that the electricity production cost in biogas utility roughly corresponds to the historical FIT regarding electricity production using RES. However, if in addition to the FIT the IS is provided, the analysis shows that the practice of combining both the above-mentioned instruments is not optimal because too high total support (overcompensation) is provided for a biogas utility developer. In a long-term perspective, the latter gives wrong signals for investments in new technologies and also creates unequal competition in the RES electricity market. To provide optimal biogas utilisation, it is necessary to consider several options. Both on-site production of electricity and upgrading to biomethane for use in a low pressure gas distribution network are simulated by the cost estimation model. The authors' estimates show that upgrading for use in a gas distribution network should be particularly considered taking into account the already existing infrastructure and technologies. This option requires lower support compared to support for electricity production in small-scale biogas utilities.

Smart Grid Communications System Blueprint

NASA Astrophysics Data System (ADS)

Clark, Adrian; Pavlovski, Chris

2010-10-01

Telecommunications operators are well versed in deploying 2G and 3G wireless networks. These networks presently support the mobile business user and/or retail consumer wishing to place conventional voice calls and data connections. The electrical power industry has recently commenced transformation of its distribution networks by deploying smart monitoring and control devices throughout their networks. This evolution of the network into a `smart grid' has also motivated the need to deploy wireless technologies that bridge the communication gap between the smart devices and information technology systems. The requirements of these networks differ from traditional wireless networks that communications operators have deployed, which have thus far forced energy companies to consider deploying their own wireless networks. We present our experience in deploying wireless networks to support the smart grid and highlight the key properties of these networks. These characteristics include application awareness, support for large numbers of simultaneous cell connections, high service coverage and prioritized routing of data. We also outline our target blueprint architecture that may be useful to the industry in building wireless and fixed networks to support the smart grid. By observing our experiences, telecommunications operators and equipment manufacturers will be able to augment their current networks and products in a way that accommodates the needs of the emerging industry of smart grids and intelligent electrical networks.

Interdependent networks: the fragility of control

PubMed Central

Morris, Richard G.; Barthelemy, Marc

2013-01-01

Recent work in the area of interdependent networks has focused on interactions between two systems of the same type. However, an important and ubiquitous class of systems are those involving monitoring and control, an example of interdependence between processes that are very different. In this Article, we introduce a framework for modelling ‘distributed supervisory control' in the guise of an electrical network supervised by a distributed system of control devices. The system is characterised by degrees of freedom salient to real-world systems— namely, the number of control devices, their inherent reliability, and the topology of the control network. Surprisingly, the behavior of the system depends crucially on the reliability of control devices. When devices are completely reliable, cascade sizes are percolation controlled; the number of devices being the relevant parameter. For unreliable devices, the topology of the control network is important and can dramatically reduce the resilience of the system. PMID:24067404

Optimum Aggregation and Control of Spatially Distributed Flexible Resources in Smart Grid

DOE PAGES

Bhattarai, Bishnu; Mendaza, Iker Diaz de Cerio; Myers, Kurt S.; ...

2017-03-24

This paper presents an algorithm to optimally aggregate spatially distributed flexible resources at strategic microgrid/smart-grid locations. The aggregation reduces a distribution network having thousands of nodes to an equivalent network with a few aggregated nodes, thereby enabling distribution system operators (DSOs) to make faster operational decisions. Moreover, the aggregation enables flexibility from small distributed flexible resources to be traded to different power and energy markets. A hierarchical control architecture comprising a combination of centralized and decentralized control approaches is proposed to practically deploy the aggregated flexibility. The proposed method serves as a great operational tool for DSOs to decide themore » exact amount of required flexibilities from different network section(s) for solving grid constraint violations. The effectiveness of the proposed method is demonstrated through simulation of three operational scenarios in a real low voltage distribution system having high penetrations of electric vehicles and heat pumps. Finally, the simulation results demonstrated that the aggregation helps DSOs not only in taking faster operational decisions, but also in effectively utilizing the available flexibility.« less

Optimum Aggregation and Control of Spatially Distributed Flexible Resources in Smart Grid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattarai, Bishnu; Mendaza, Iker Diaz de Cerio; Myers, Kurt S.

This paper presents an algorithm to optimally aggregate spatially distributed flexible resources at strategic microgrid/smart-grid locations. The aggregation reduces a distribution network having thousands of nodes to an equivalent network with a few aggregated nodes, thereby enabling distribution system operators (DSOs) to make faster operational decisions. Moreover, the aggregation enables flexibility from small distributed flexible resources to be traded to different power and energy markets. A hierarchical control architecture comprising a combination of centralized and decentralized control approaches is proposed to practically deploy the aggregated flexibility. The proposed method serves as a great operational tool for DSOs to decide themore » exact amount of required flexibilities from different network section(s) for solving grid constraint violations. The effectiveness of the proposed method is demonstrated through simulation of three operational scenarios in a real low voltage distribution system having high penetrations of electric vehicles and heat pumps. Finally, the simulation results demonstrated that the aggregation helps DSOs not only in taking faster operational decisions, but also in effectively utilizing the available flexibility.« less

Impact of impedance unbalance on the efficiency of electricity transmission and distribution - A case study

NASA Astrophysics Data System (ADS)

Pavlov, L'uboš; Skurčák, L'uboš; Chovanec, Juraj; Altus, Juraj

2017-11-01

This article is devoted to the analysis of the possible influence of impedance asymmetry on the efficiency of electricity transmission and distribution in the electricity system in Slovakia, at a voltage level of 110 kV - 400 kV, using synchronic phasor monitoring results. For simplicity of calculations, in practice, the impedance imbalance from mutual interfacial inductive capacitances bonds is neglected. In this way, the 3-phase network is interpreted as symmetrical in the calculations. In this case, it is possible to determine only some components of losses (ohmic losses, corona loss, leakages, etc). The influence of impedance asymmetry can be quantified by calculation using the results of the monitoring of the synchronous phasors of selected electricity system elements (OHL, transformer, choke) or by 3-phase modelling of real system elements. frequency to test the transformer for induced over voltage test, and its characteristics is analysed.

Heterogeneous collaborative sensor network for electrical management of an automated house with PV energy.

PubMed

Castillo-Cagigal, Manuel; Matallanas, Eduardo; Gutiérrez, Alvaro; Monasterio-Huelin, Félix; Caamaño-Martín, Estefaná; Masa-Bote, Daniel; Jiménez-Leube, Javier

2011-01-01

In this paper we present a heterogeneous collaborative sensor network for electrical management in the residential sector. Improving demand-side management is very important in distributed energy generation applications. Sensing and control are the foundations of the "Smart Grid" which is the future of large-scale energy management. The system presented in this paper has been developed on a self-sufficient solar house called "MagicBox" equipped with grid connection, PV generation, lead-acid batteries, controllable appliances and smart metering. Therefore, there is a large number of energy variables to be monitored that allow us to precisely manage the energy performance of the house by means of collaborative sensors. The experimental results, performed on a real house, demonstrate the feasibility of the proposed collaborative system to reduce the consumption of electrical power and to increase energy efficiency.

Load flows and faults considering dc current injections

NASA Technical Reports Server (NTRS)

Kusic, G. L.; Beach, R. F.

1991-01-01

The authors present novel methods for incorporating current injection sources into dc power flow computations and determining network fault currents when electronic devices limit fault currents. Combinations of current and voltage sources into a single network are considered in a general formulation. An example of relay coordination is presented. The present study is pertinent to the development of the Space Station Freedom electrical generation, transmission, and distribution system.

Modeling MAC layer for powerline communications networks

NASA Astrophysics Data System (ADS)

Hrasnica, Halid; Haidine, Abdelfatteh

2001-02-01

The usage of electrical power distribution networks for voice and data transmission, called Powerline Communications, becomes nowadays more and more attractive, particularly in the telecommunication access area. The most important reasons for that are the deregulation of the telecommunication market and a fact that the access networks are still property of former monopolistic companies. In this work, first we analyze a PLC network and system structure as well as a disturbance scenario in powerline networks. After that, we define a logical structure of the powerline MAC layer and propose the reservation MAC protocols for the usage in the PLC network which provides collision free data transmission. This makes possible better network utilization and realization of QoS guarantees which can make PLC networks competitive to other access technologies.

Relative Localization in Wireless Sensor Networks for Measurement of Electric Fields under HVDC Transmission Lines

PubMed Central

Cui, Yong; Wang, Qiusheng; Yuan, Haiwen; Song, Xiao; Hu, Xuemin; Zhao, Luxing

2015-01-01

In the wireless sensor networks (WSNs) for electric field measurement system under the High-Voltage Direct Current (HVDC) transmission lines, it is necessary to obtain the electric field distribution with multiple sensors. The location information of each sensor is essential to the correct analysis of measurement results. Compared with the existing approach which gathers the location information by manually labelling sensors during deployment, the automatic localization can reduce the workload and improve the measurement efficiency. A novel and practical range-free localization algorithm for the localization of one-dimensional linear topology wireless networks in the electric field measurement system is presented. The algorithm utilizes unknown nodes' neighbor lists based on the Received Signal Strength Indicator (RSSI) values to determine the relative locations of nodes. The algorithm is able to handle the exceptional situation of the output permutation which can effectively improve the accuracy of localization. The performance of this algorithm under real circumstances has been evaluated through several experiments with different numbers of nodes and different node deployments in the China State Grid HVDC test base. Results show that the proposed algorithm achieves an accuracy of over 96% under different conditions. PMID:25658390

Relative localization in wireless sensor networks for measurement of electric fields under HVDC transmission lines.

PubMed

Cui, Yong; Wang, Qiusheng; Yuan, Haiwen; Song, Xiao; Hu, Xuemin; Zhao, Luxing

2015-02-04

In the wireless sensor networks (WSNs) for electric field measurement system under the High-Voltage Direct Current (HVDC) transmission lines, it is necessary to obtain the electric field distribution with multiple sensors. The location information of each sensor is essential to the correct analysis of measurement results. Compared with the existing approach which gathers the location information by manually labelling sensors during deployment, the automatic localization can reduce the workload and improve the measurement efficiency. A novel and practical range-free localization algorithm for the localization of one-dimensional linear topology wireless networks in the electric field measurement system is presented. The algorithm utilizes unknown nodes' neighbor lists based on the Received Signal Strength Indicator (RSSI) values to determine the relative locations of nodes. The algorithm is able to handle the exceptional situation of the output permutation which can effectively improve the accuracy of localization. The performance of this algorithm under real circumstances has been evaluated through several experiments with different numbers of nodes and different node deployments in the China State Grid HVDC test base. Results show that the proposed algorithm achieves an accuracy of over 96% under different conditions.

A study using a Monte Carlo method of the optimal configuration of a distribution network in terms of power loss sensing.

PubMed

Moon, Hyun Ho; Lee, Jong Joo; Choi, Sang Yule; Cha, Jae Sang; Kang, Jang Mook; Kim, Jong Tae; Shin, Myong Chul

2011-01-01

Recently there have been many studies of power systems with a focus on "New and Renewable Energy" as part of "New Growth Engine Industry" promoted by the Korean government. "New And Renewable Energy"-especially focused on wind energy, solar energy and fuel cells that will replace conventional fossil fuels-is a part of the Power-IT Sector which is the basis of the SmartGrid. A SmartGrid is a form of highly-efficient intelligent electricity network that allows interactivity (two-way communications) between suppliers and consumers by utilizing information technology in electricity production, transmission, distribution and consumption. The New and Renewable Energy Program has been driven with a goal to develop and spread through intensive studies, by public or private institutions, new and renewable energy which, unlike conventional systems, have been operated through connections with various kinds of distributed power generation systems. Considerable research on smart grids has been pursued in the United States and Europe. In the United States, a variety of research activities on the smart power grid have been conducted within EPRI's IntelliGrid research program. The European Union (EU), which represents Europe's Smart Grid policy, has focused on an expansion of distributed generation (decentralized generation) and power trade between countries with improved environmental protection. Thus, there is current emphasis on a need for studies that assesses the economic efficiency of such distributed generation systems. In this paper, based on the cost of distributed power generation capacity, calculations of the best profits obtainable were made by a Monte Carlo simulation. Monte Carlo simulations that rely on repeated random sampling to compute their results take into account the cost of electricity production, daily loads and the cost of sales and generate a result faster than mathematical computations. In addition, we have suggested the optimal design, which considers the distribution loss associated with power distribution systems focus on sensing aspect and distributed power generation.

Electricity exchange and the valuation of transnational transmission access: A case study of intra-regional integration of the electric industries of Argentina and Chile

NASA Astrophysics Data System (ADS)

Brereton, Beverly Ann

The interconnection of neighboring electricity networks provides opportunities for the realization of synergies between electricity systems. Examples of the synergies to be realized are the rationalized management of the electricity networks whose fuel source domination differs, and the exploitation of non-coincident system peak demands. These factors allow technology diversity in the satisfaction of electricity demand, the coordination of planning and maintenance schedules between the networks by exploiting the cost differences in the pool of generation assets and the load configuration differences in the neighboring locations. The interconnection decision studied in this dissertation focused on the electricity networks of Argentina and Chile whose electricity systems operate in isolation at the current time. The cooperative game-theoretic framework was applied in the analysis of the decision facing the two countries and the net surplus to be derived from interconnection was evaluated. Measurement of the net gains from interconnection used in this study were reflected in changes in generating costs under the assumption that demand is fixed under all scenarios. With the demand for electricity assumed perfectly inelastic, passive or aggressive bidding strategies were considered under the scenarios for the generators in the two countries. The interconnection decision was modeled using a linear power flow model which utilizes linear programming techniques to reflect dispatch procedures based on generation bids. Results of the study indicate that the current interconnection project between Argentina and Chile will not result in positive net surplus under a variety of scenarios. Only under significantly reduced interconnection cost will the venture prove attractive. Possible sharing mechanisms were also explored in the research and a symmetric distribution of the net surplus to be derived under the reduced interconnection cost scenario was recommended to preserve equity in the allocation of the interconnection gains.

Stress-induced electric current fluctuations in rocks: a superstatistical model

NASA Astrophysics Data System (ADS)

Cartwright-Taylor, Alexis; Vallianatos, Filippos; Sammonds, Peter

2017-04-01

We recorded spontaneous electric current flow in non-piezoelectric Carrara marble samples during triaxial deformation. Mechanical data, ultrasonic velocities and acoustic emissions were acquired simultaneously with electric current to constrain the relationship between electric current flow, differential stress and damage. Under strain-controlled loading, spontaneous electric current signals (nA) were generated and sustained under all conditions tested. In dry samples, a detectable electric current arises only during dilatancy and the overall signal is correlated with the damage induced by microcracking. Our results show that fracture plays a key role in the generation of electric currents in deforming rocks (Cartwright-Taylor et al., in prep). We also analysed the high-frequency fluctuations of these electric current signals and found that they are not normally distributed - they exhibit power-law tails (Cartwright-Taylor et al., 2014). We modelled these distributions with q-Gaussian statistics, derived by maximising the Tsallis entropy. This definition of entropy is particularly applicable to systems which are strongly correlated and far from equilibrium. Good agreement, at all experimental conditions, between the distributions of electric current fluctuations and the q-Gaussian function with q-values far from one, illustrates the highly correlated, fractal nature of the electric source network within the samples and provides further evidence that the source of the electric signals is the developing fractal network of cracks. It has been shown (Beck, 2001) that q-Gaussian distributions can arise from the superposition of local relaxations in the presence of a slowly varying driving force, thus providing a dynamic reason for the appearance of Tsallis statistics in systems with a fluctuating energy dissipation rate. So, the probability distribution for a dynamic variable, u under some external slow forcing, β, can be obtained as a superposition of temporary local equilibrium processes whose variance fluctuates over time. The appearance of q-Gaussian statistics are caused by the fluctuating β parameter, which effectively models the fluctuating energy dissipation rate in the system. This concept is known as superstatistics and is physically relevant for modelling driven non-equilibrium systems where the environmental conditions fluctuate on a large scale. The idea is that the environmental variable, such as temperature or pressure, changes so slowly that a rapidly fluctuating variable within that environment has time to relax back to equilibrium between each change in the environment. The application of superstatistical techniques to our experimental electric current fluctuations show that they can indeed be described, to good approximation, by the superposition of local Gaussian processes with fluctuating variance. We conclude, then, that the measured electric current fluctuates in response to intermittent energy dissipation and is driven to varying temporary local equilibria during deformation by the variations in stress intensity. The advantage of this technique is that, once the model has been established to be a good description of the system in question, the average β parameter (a measure of the average energy dissipation rate) for the system can be obtained simply from the macroscopic q-Gaussian distribution parameters.

Autonomous, Decentralized Grid Architecture: Prosumer-Based Distributed Autonomous Cyber-Physical Architecture for Ultra-Reliable Green Electricity Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2012-01-11

GENI Project: Georgia Tech is developing a decentralized, autonomous, internet-like control architecture and control software system for the electric power grid. Georgia Tech’s new architecture is based on the emerging concept of electricity prosumers—economically motivated actors that can produce, consume, or store electricity. Under Georgia Tech’s architecture, all of the actors in an energy system are empowered to offer associated energy services based on their capabilities. The actors achieve their sustainability, efficiency, reliability, and economic objectives, while contributing to system-wide reliability and efficiency goals. This is in marked contrast to the current one-way, centralized control paradigm.

Simulation Tools and Techniques for Analyzing the Impacts of Photovoltaic System Integration

NASA Astrophysics Data System (ADS)

Hariri, Ali

Solar photovoltaic (PV) energy integration in distribution networks is one of the fastest growing sectors of distributed energy integration. The growth in solar PV integration is incentivized by various clean power policies, global interest in solar energy, and reduction in manufacturing and installation costs of solar energy systems. The increase in solar PV integration has raised a number of concerns regarding the potential impacts that might arise as a result of high PV penetration. Some impacts have already been recorded in networks with high PV penetration such as in China, Germany, and USA (Hawaii and California). Therefore, network planning is becoming more intricate as new technologies are integrated into the existing electric grid. The integrated new technologies pose certain compatibility concerns regarding the existing electric grid infrastructure. Therefore, PV integration impact studies are becoming more essential in order to have a better understanding of how to advance the solar PV integration efforts without introducing adverse impacts into the network. PV impact studies are important for understanding the nature of the new introduced phenomena. Understanding the nature of the potential impacts is a key factor for mitigating and accommodating for said impacts. Traditionally, electric power utilities relied on phasor-based power flow simulations for planning their electric networks. However, the conventional, commercially available, phasor-based simulation tools do not provide proper visibility across a wide spectrum of electric phenomena. Moreover, different types of simulation approaches are suitable for specific types of studies. For instance, power flow software cannot be used for studying time varying phenomena. At the same time, it is not practical to use electromagnetic transient (EMT) tools to perform power flow solutions. Therefore, some electric phenomena caused by the variability of PV generation are not visible using the conventional utility simulation software. On the other hand, EMT simulation tools provide high accuracy and visibility over a wide bandwidth of frequencies at the expense of larger processing and memory requirements, limited network size, and long simulation time. Therefore, there is a gap in simulation tools and techniques that can efficiently and effectively identify potential PV impact. New planning simulation tools are needed in order to accommodate for the simulation requirements of new integrated technologies in the electric grid. The dissertation at hand starts by identifying some of the potential impacts that are caused by high PV penetration. A phasor-based quasi-static time series (QSTS) analysis tool is developed in order to study the slow dynamics that are caused by the variations in the PV generation that lead to voltage fluctuations. Moreover, some EMT simulations are performed in order to study the impacts of PV systems on the electric network harmonic levels. These studies provide insights into the type and duration of certain impacts, as well as the conditions that may lead to adverse phenomena. In addition these studies present an idea about the type of simulation tools that are sufficient for each type of study. After identifying some of the potential impacts, certain planning tools and techniques are proposed. The potential PV impacts may cause certain utilities to refrain from integrating PV systems into their networks. However, each electric network has a certain limit beyond which the impacts become substantial and may adversely interfere with the system operation and the equipment along the feeder; this limit is referred to as the hosting limit (or hosting capacity). Therefore, it is important for utilities to identify the PV hosting limit on a specific electric network in order to safely and confidently integrate the maximum possible PV systems. In the following dissertation, two approaches have been proposed for identifying the hosing limit: 1. Analytical approach: this is a theoretical mathematical approach that demonstrated the understanding of the fundamentals of electric power system operation. It provides an easy way to estimate the maximum amount of PV power that can be injected at each node in the network. This approach has been tested and validated. 2. Stochastic simulation software approach: this approach provides a comprehensive simulation software that can be used in order to identify the PV hosting limit. The software performs a large number of stochastic simulation while varying the PV system size and location. The collected data is then analyzed for violations in the voltage levels, voltage fluctuations and reverse power flow. (Abstract shortened by ProQuest.).

Alternative energy balances for Bulgaria to mitigate climate change

NASA Astrophysics Data System (ADS)

Christov, Christo

1996-01-01

Alternative energy balances aimed to mitigate greenhouse gas (GHG) emissions are developed as alternatives to the baseline energy balance. The section of mitigation options is based on the results of the GHG emission inventory for the 1987 1992 period. The energy sector is the main contributor to the total CO2 emissions of Bulgaria. Stationary combustion for heat and electricity production as well as direct end-use combustion amounts to 80% of the total emissions. The parts of the energy network that could have the biggest influence on GHG emission reduction are identified. The potential effects of the following mitigation measures are discussed: rehabilitation of the combustion facilities currently in operation; repowering to natural gas; reduction of losses in thermal and electrical transmission and distribution networks; penetration of new combustion technologies; tariff structure improvement; renewable sources for electricity and heat production; wasteheat utilization; and supply of households with natural gas to substitute for electricity in space heating and cooking. The total available and the achievable potentials are estimated and the implementation barriers are discussed.

Hybrid power system intelligent operation and protection involving distributed architectures and pulsed loads

NASA Astrophysics Data System (ADS)

Mohamed, Ahmed

Efficient and reliable techniques for power delivery and utilization are needed to account for the increased penetration of renewable energy sources in electric power systems. Such methods are also required for current and future demands of plug-in electric vehicles and high-power electronic loads. Distributed control and optimal power network architectures will lead to viable solutions to the energy management issue with high level of reliability and security. This dissertation is aimed at developing and verifying new techniques for distributed control by deploying DC microgrids, involving distributed renewable generation and energy storage, through the operating AC power system. To achieve the findings of this dissertation, an energy system architecture was developed involving AC and DC networks, both with distributed generations and demands. The various components of the DC microgrid were designed and built including DC-DC converters, voltage source inverters (VSI) and AC-DC rectifiers featuring novel designs developed by the candidate. New control techniques were developed and implemented to maximize the operating range of the power conditioning units used for integrating renewable energy into the DC bus. The control and operation of the DC microgrids in the hybrid AC/DC system involve intelligent energy management. Real-time energy management algorithms were developed and experimentally verified. These algorithms are based on intelligent decision-making elements along with an optimization process. This was aimed at enhancing the overall performance of the power system and mitigating the effect of heavy non-linear loads with variable intensity and duration. The developed algorithms were also used for managing the charging/discharging process of plug-in electric vehicle emulators. The protection of the proposed hybrid AC/DC power system was studied. Fault analysis and protection scheme and coordination, in addition to ideas on how to retrofit currently available protection concepts and devices for AC systems in a DC network, were presented. A study was also conducted on the effect of changing the distribution architecture and distributing the storage assets on the various zones of the network on the system's dynamic security and stability. A practical shipboard power system was studied as an example of a hybrid AC/DC power system involving pulsed loads. Generally, the proposed hybrid AC/DC power system, besides most of the ideas, controls and algorithms presented in this dissertation, were experimentally verified at the Smart Grid Testbed, Energy Systems Research Laboratory. All the developments in this dissertation were experimentally verified at the Smart Grid Testbed.

Assessment of critical path analyses of the relationship between permeability and electrical conductivity of pore networks

NASA Astrophysics Data System (ADS)

Skaggs, Todd H.

2011-10-01

Critical path analysis (CPA) is a method for estimating macroscopic transport coefficients of heterogeneous materials that are highly disordered at the micro-scale. Developed originally to model conduction in semiconductors, numerous researchers have noted that CPA might also have relevance to flow and transport processes in porous media. However, the results of several numerical investigations of critical path analysis on pore network models raise questions about the applicability of CPA to porous media. Among other things, these studies found that (i) in well-connected 3D networks, CPA predictions were inaccurate and became worse when heterogeneity was increased; and (ii) CPA could not fully explain the transport properties of 2D networks. To better understand the applicability of CPA to porous media, we made numerical computations of permeability and electrical conductivity on 2D and 3D networks with differing pore-size distributions and geometries. A new CPA model for the relationship between the permeability and electrical conductivity was found to be in good agreement with numerical data, and to be a significant improvement over a classical CPA model. In sufficiently disordered 3D networks, the new CPA prediction was within ±20% of the true value, and was nearly optimal in terms of minimizing the squared prediction errors across differing network configurations. The agreement of CPA predictions with 2D network computations was similarly good, although 2D networks are in general not well-suited for evaluating CPA. Numerical transport coefficients derived for regular 3D networks of slit-shaped pores were found to be in better agreement with experimental data from rock samples than were coefficients derived for networks of cylindrical pores.

Distributed Energy Systems Integration and Demand Optimization for Autonomous Operations and Electric Grid Transactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghatikar, Girish; Mashayekh, Salman; Stadler, Michael

Distributed power systems in the U.S. and globally are evolving to provide reliable and clean energy to consumers. In California, existing regulations require significant increases in renewable generation, as well as identification of customer-side distributed energy resources (DER) controls, communication technologies, and standards for interconnection with the electric grid systems. As DER deployment expands, customer-side DER control and optimization will be critical for system flexibility and demand response (DR) participation, which improves the economic viability of DER systems. Current DER systems integration and communication challenges include leveraging the existing DER and DR technology and systems infrastructure, and enabling optimized cost,more » energy and carbon choices for customers to deploy interoperable grid transactions and renewable energy systems at scale. Our paper presents a cost-effective solution to these challenges by exploring communication technologies and information models for DER system integration and interoperability. This system uses open standards and optimization models for resource planning based on dynamic-pricing notifications and autonomous operations within various domains of the smart grid energy system. It identifies architectures and customer engagement strategies in dynamic DR pricing transactions to generate feedback information models for load flexibility, load profiles, and participation schedules. The models are tested at a real site in California—Fort Hunter Liggett (FHL). Furthermore, our results for FHL show that the model fits within the existing and new DR business models and networked systems for transactive energy concepts. Integrated energy systems, communication networks, and modeling tools that coordinate supply-side networks and DER will enable electric grid system operators to use DER for grid transactions in an integrated system.« less

Voltage profile program for the Kennedy Space Center electric power distribution system

NASA Technical Reports Server (NTRS)

1976-01-01

The Kennedy Space Center voltage profile program computes voltages at all busses greater than 1 Kv in the network under various conditions of load. The computation is based upon power flow principles and utilizes a Newton-Raphson iterative load flow algorithm. Power flow conditions throughout the network are also provided. The computer program is designed for both steady state and transient operation. In the steady state mode, automatic tap changing of primary distribution transformers is incorporated. Under transient conditions, such as motor starts etc., it is assumed that tap changing is not accomplished so that transformer secondary voltage is allowed to sag.

Distribution path robust optimization of electric vehicle with multiple distribution centers

PubMed Central

Hao, Wei; He, Ruichun; Jia, Xiaoyan; Pan, Fuquan; Fan, Jing; Xiong, Ruiqi

2018-01-01

To identify electrical vehicle (EV) distribution paths with high robustness, insensitivity to uncertainty factors, and detailed road-by-road schemes, optimization of the distribution path problem of EV with multiple distribution centers and considering the charging facilities is necessary. With the minimum transport time as the goal, a robust optimization model of EV distribution path with adjustable robustness is established based on Bertsimas’ theory of robust discrete optimization. An enhanced three-segment genetic algorithm is also developed to solve the model, such that the optimal distribution scheme initially contains all road-by-road path data using the three-segment mixed coding and decoding method. During genetic manipulation, different interlacing and mutation operations are carried out on different chromosomes, while, during population evolution, the infeasible solution is naturally avoided. A part of the road network of Xifeng District in Qingyang City is taken as an example to test the model and the algorithm in this study, and the concrete transportation paths are utilized in the final distribution scheme. Therefore, more robust EV distribution paths with multiple distribution centers can be obtained using the robust optimization model. PMID:29518169

Regulation and competition without privatization: Norway`s experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moen, J.; Hamrin, J.

The competitive market for the hydro-based Norwegian electricity system is working well, with end-user prices only slightly above the wholesale market. Pool prices are reflecting only weather-related variations, and no market power abuses are evident. The challenge now is to restructure ownership of the wires and retail suppliers to lower wheeling costs and avoid cross-subsidization. Since the Norwegian Energy Act came into effect in 1991, the electricity industry in Norway has operated as one of the most deregulated electricity industries in the world. The Energy Act introduced third party access to the retail market and competition in electricity production. Themore » generation, sale and purchase of electricity is now highly competitive, with customers free to buy electricity from any generator, trader or the electricity Pool. Transmission pricing was separated from power purchasing arrangements, so that the buying and selling of electricity as a product is distinct from the transmission of electricity as a service. Transmission and distribution networks continue to maintain natural monopolies, with network owners providing wheeling service across their networks to customers who are connected to them. These monopoly sectors of the industry are subject to regulation by the government-appointed regulatory body, Norwegian Water Resources and Energy Administration (NVE). Regulation is on a cost-of-service basis, with the revenue allowance determined by NVE. The main force behind the Norwegian reform was the desire for efficiency gains to be achieved through a total restructure of the commercial character of the energy service industry (ESI). Unlike the U.K., in Norway the monopoly franchise for both generation and retail supply was removed in one step without any transition period, and the old pool was reformed to provide the needed structure for this new competitive energy market.« less

Distributed cooperative control of AC microgrids

NASA Astrophysics Data System (ADS)

Bidram, Ali

In this dissertation, the comprehensive secondary control of electric power microgrids is of concern. Microgrid technical challenges are mainly realized through the hierarchical control structure, including primary, secondary, and tertiary control levels. Primary control level is locally implemented at each distributed generator (DG), while the secondary and tertiary control levels are conventionally implemented through a centralized control structure. The centralized structure requires a central controller which increases the reliability concerns by posing the single point of failure. In this dissertation, the distributed control structure using the distributed cooperative control of multi-agent systems is exploited to increase the secondary control reliability. The secondary control objectives are microgrid voltage and frequency, and distributed generators (DGs) active and reactive powers. Fully distributed control protocols are implemented through distributed communication networks. In the distributed control structure, each DG only requires its own information and the information of its neighbors on the communication network. The distributed structure obviates the requirements for a central controller and complex communication network which, in turn, improves the system reliability. Since the DG dynamics are nonlinear and non-identical, input-output feedback linearization is used to transform the nonlinear dynamics of DGs to linear dynamics. Proposed control frameworks cover the control of microgrids containing inverter-based DGs. Typical microgrid test systems are used to verify the effectiveness of the proposed control protocols.

Guest Editorial Introduction to the Special Issue on 'Advanced Signal Processing Techniques and Telecommunications Network Infrastructures for Smart Grid Analysis, Monitoring, and Management'

DOE PAGES

Bracale, Antonio; Barros, Julio; Cacciapuoti, Angela Sara; ...

2015-06-10

Electrical power systems are undergoing a radical change in structure, components, and operational paradigms, and are progressively approaching the new concept of smart grids (SGs). Future power distribution systems will be characterized by the simultaneous presence of various distributed resources, such as renewable energy systems (i.e., photovoltaic power plant and wind farms), storage systems, and controllable/non-controllable loads. Control and optimization architectures will enable network-wide coordination of these grid components in order to improve system efficiency and reliability and to limit greenhouse gas emissions. In this context, the energy flows will be bidirectional from large power plants to end users andmore » vice versa; producers and consumers will continuously interact at different voltage levels to determine in advance the requests of loads and to adapt the production and demand for electricity flexibly and efficiently also taking into account the presence of storage systems.« less

Heterogeneous Collaborative Sensor Network for Electrical Management of an Automated House with PV Energy

PubMed Central

Castillo-Cagigal, Manuel; Matallanas, Eduardo; Gutiérrez, Álvaro; Monasterio-Huelin, Félix; Caamaño-Martín, Estefaná; Masa-Bote, Daniel; Jiménez-Leube, Javier

2011-01-01

In this paper we present a heterogeneous collaborative sensor network for electrical management in the residential sector. Improving demand-side management is very important in distributed energy generation applications. Sensing and control are the foundations of the “Smart Grid” which is the future of large-scale energy management. The system presented in this paper has been developed on a self-sufficient solar house called “MagicBox” equipped with grid connection, PV generation, lead-acid batteries, controllable appliances and smart metering. Therefore, there is a large number of energy variables to be monitored that allow us to precisely manage the energy performance of the house by means of collaborative sensors. The experimental results, performed on a real house, demonstrate the feasibility of the proposed collaborative system to reduce the consumption of electrical power and to increase energy efficiency. PMID:22247680

Community Microgrid Scheduling Considering Network Operational Constraints and Building Thermal Dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Guodong; Ollis, Thomas B.; Xiao, Bailu

Here, this paper proposes a Mixed Integer Conic Programming (MICP) model for community microgrids considering the network operational constraints and building thermal dynamics. The proposed optimization model optimizes not only the operating cost, including fuel cost, purchasing cost, battery degradation cost, voluntary load shedding cost and the cost associated with customer discomfort due to room temperature deviation from the set point, but also several performance indices, including voltage deviation, network power loss and power factor at the Point of Common Coupling (PCC). In particular, the detailed thermal dynamic model of buildings is integrated into the distribution optimal power flow (D-OPF)more » model for the optimal operation of community microgrids. The heating, ventilation and air-conditioning (HVAC) systems can be scheduled intelligently to reduce the electricity cost while maintaining the indoor temperature in the comfort range set by customers. Numerical simulation results show the effectiveness of the proposed model and significant saving in electricity cost could be achieved with network operational constraints satisfied.« less

Community Microgrid Scheduling Considering Network Operational Constraints and Building Thermal Dynamics

DOE PAGES

Liu, Guodong; Ollis, Thomas B.; Xiao, Bailu; ...

2017-10-10

Here, this paper proposes a Mixed Integer Conic Programming (MICP) model for community microgrids considering the network operational constraints and building thermal dynamics. The proposed optimization model optimizes not only the operating cost, including fuel cost, purchasing cost, battery degradation cost, voluntary load shedding cost and the cost associated with customer discomfort due to room temperature deviation from the set point, but also several performance indices, including voltage deviation, network power loss and power factor at the Point of Common Coupling (PCC). In particular, the detailed thermal dynamic model of buildings is integrated into the distribution optimal power flow (D-OPF)more » model for the optimal operation of community microgrids. The heating, ventilation and air-conditioning (HVAC) systems can be scheduled intelligently to reduce the electricity cost while maintaining the indoor temperature in the comfort range set by customers. Numerical simulation results show the effectiveness of the proposed model and significant saving in electricity cost could be achieved with network operational constraints satisfied.« less

An analysis of electrical conductivity model in saturated porous media

NASA Astrophysics Data System (ADS)

Cai, J.; Wei, W.; Qin, X.; Hu, X.

2017-12-01

Electrical conductivity of saturated porous media has numerous applications in many fields. In recent years, the number of theoretical methods to model electrical conductivity of complex porous media has dramatically increased. Nevertheless, the process of modeling the spatial conductivity distributed function continues to present challenges when these models used in reservoirs, particularly in porous media with strongly heterogeneous pore-space distributions. Many experiments show a more complex distribution of electrical conductivity data than the predictions derived from the experiential model. Studies have observed anomalously-high electrical conductivity of some low-porosity (tight) formations compared to more- porous reservoir rocks, which indicates current flow in porous media is complex and difficult to predict. Moreover, the change of electrical conductivity depends not only on the pore volume fraction but also on several geometric properties of the more extensive pore network, including pore interconnection and tortuosity. In our understanding of electrical conductivity models in porous media, we study the applicability of several well-known methods/theories to electrical characteristics of porous rocks as a function of pore volume, tortuosity and interconnection, to estimate electrical conductivity based on the micro-geometrical properties of rocks. We analyze the state of the art of scientific knowledge and practice for modeling porous structural systems, with the purpose of identifying current limitations and defining a blueprint for future modeling advances. We compare conceptual descriptions of electrical current flow processes in pore space considering several distinct modeling approaches. Approaches to obtaining more reasonable electrical conductivity models are discussed. Experiments suggest more complex relationships between electrical conductivity and porosity than experiential models, particularly in low-porosity formations. However, the available theoretical models combined with simulations do provide insight to how microscale physics affects macroscale electrical conductivity in porous media.

Solar microclimatology. [tables (data) on insolation for application to solar energy conversion by electric power plants

NASA Technical Reports Server (NTRS)

Mckenney, D. B.; Beauchamp, W. T.

1975-01-01

It has become apparent in recent years that solar energy can be used for electric power production by several methods. Because of the diffuse nature of the solar insolation, the area involved in any central power plant design can encompass several square miles. A detailed design of these large area collection systems will require precise knowledge of the local solar insolation. Detailed information will also be needed concerning the temporal nature of the insolation and the local spatial distribution. Therefore, insolation data was collected and analyzed for a network of sensors distributed over an area of several square kilometers in Arizona. The analyses of this data yielded probability distributions of cloud size, velocity, and direction of motion which were compared with data obtained from the National Weather Service. Microclimatological analyses were also performed for suitable modeling parameters pertinent to large scale electric power plant design. Instrumentation used to collect the data is described.

Solar thermal power systems point-focusing distributed receiver technology project. Volume 2: Detailed report

NASA Technical Reports Server (NTRS)

1980-01-01

The accomplishments of the Point-Focusing Distributed Receiver Technology Project during fiscal year 1979 are detailed. Present studies involve designs of modular units that collect and concentrate solar energy via highly reflective, parabolic-shaped dishes. The concentrated energy is then converted to heat in a working fluid, such as hot gas. In modules designed to produce heat for industrial applications, a flexible line conveys the heated fluid from the module to a heat transfer network. In modules designed to produce electricity the fluid carries the heat directly to an engine in a power conversion unit located at the focus of the concentrator. The engine is mechanically linked to an electric generator. A Brayton-cycle engine is currently being developed as the most promising electrical energy converter to meet near-future needs.

Evaluating conducting network based transparent electrodes from geometrical considerations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Ankush; Kulkarni, G. U., E-mail: guk@cens.res.in

2016-01-07

Conducting nanowire networks have been developed as viable alternative to existing indium tin oxide based transparent electrode (TE). The nature of electrical conduction and process optimization for electrodes have gained much from the theoretical models based on percolation transport using Monte Carlo approach and applying Kirchhoff's law on individual junctions and loops. While most of the literature work pertaining to theoretical analysis is focussed on networks obtained from conducting rods (mostly considering only junction resistance), hardly any attention has been paid to those made using template based methods, wherein the structure of network is neither similar to network obtained frommore » conducting rods nor similar to well periodic geometry. Here, we have attempted an analytical treatment based on geometrical arguments and applied image analysis on practical networks to gain deeper insight into conducting networked structure particularly in relation to sheet resistance and transmittance. Many literature examples reporting networks with straight or curvilinear wires with distributions in wire width and length have been analysed by treating the networks as two dimensional graphs and evaluating the sheet resistance based on wire density and wire width. The sheet resistance values from our analysis compare well with the experimental values. Our analysis on various examples has revealed that low sheet resistance is achieved with high wire density and compactness with straight rather than curvilinear wires and with narrower wire width distribution. Similarly, higher transmittance for given sheet resistance is possible with narrower wire width but of higher thickness, minimal curvilinearity, and maximum connectivity. For the purpose of evaluating active fraction of the network, the algorithm was made to distinguish and quantify current carrying backbone regions as against regions containing only dangling or isolated wires. The treatment can be helpful in predicting the properties of a network simply from image analysis and will be helpful in improvisation and comparison of various TEs and better understanding of electrical percolation.« less

Evaluating conducting network based transparent electrodes from geometrical considerations

NASA Astrophysics Data System (ADS)

Kumar, Ankush; Kulkarni, G. U.

2016-01-01

Conducting nanowire networks have been developed as viable alternative to existing indium tin oxide based transparent electrode (TE). The nature of electrical conduction and process optimization for electrodes have gained much from the theoretical models based on percolation transport using Monte Carlo approach and applying Kirchhoff's law on individual junctions and loops. While most of the literature work pertaining to theoretical analysis is focussed on networks obtained from conducting rods (mostly considering only junction resistance), hardly any attention has been paid to those made using template based methods, wherein the structure of network is neither similar to network obtained from conducting rods nor similar to well periodic geometry. Here, we have attempted an analytical treatment based on geometrical arguments and applied image analysis on practical networks to gain deeper insight into conducting networked structure particularly in relation to sheet resistance and transmittance. Many literature examples reporting networks with straight or curvilinear wires with distributions in wire width and length have been analysed by treating the networks as two dimensional graphs and evaluating the sheet resistance based on wire density and wire width. The sheet resistance values from our analysis compare well with the experimental values. Our analysis on various examples has revealed that low sheet resistance is achieved with high wire density and compactness with straight rather than curvilinear wires and with narrower wire width distribution. Similarly, higher transmittance for given sheet resistance is possible with narrower wire width but of higher thickness, minimal curvilinearity, and maximum connectivity. For the purpose of evaluating active fraction of the network, the algorithm was made to distinguish and quantify current carrying backbone regions as against regions containing only dangling or isolated wires. The treatment can be helpful in predicting the properties of a network simply from image analysis and will be helpful in improvisation and comparison of various TEs and better understanding of electrical percolation.

Illustration of distributed generation effects on protection system coordination

NASA Astrophysics Data System (ADS)

Alawami, Hussain Adnan

Environmental concerns, market forces, and emergence of new technologies have recently resulted in restructuring electric utility from vertically integrated networks to competitive deregulated entities. Distributed generation (DG) is playing a major role in such deregulated markets. When they are installed in small amounts and small sizes, their impacts on the system may be negligible. When their penetration levels increase as well as their sizes, however, they may start affecting the system performance from more than one aspect. Power system protection needs to be re-assessed after the emergence of DG. This thesis attempts to illustrate the impact of DG on the power system protection coordination. It will study the operation of the impedance relays, fuses, reclosers and overcurrent relays when a DG is added to the distribution network. Different DG sizes, distances from the network and locations within the distribution system will be considered. Power system protection coordination is very sensitive to the DG size where it is not for the DG distance. DG location has direct impact on the operation of the protective devices especially when it is inserted in the middle point of the distribution system. Key Words, Distributed Generation, Impedance relay, fuses, reclosers, overcurrent relays, power system protection coordination.

Vibration reduction for smart periodic structures via periodic piezoelectric arrays with nonlinear interleaved-switched electronic networks

NASA Astrophysics Data System (ADS)

Bao, Bin; Guyomar, Daniel; Lallart, Mickaël

2017-01-01

Smart periodic structures covered by periodically distributed piezoelectric patches have drawn more and more attention in recent years for wave propagation attenuation and corresponding structural vibration suppression. Since piezoelectric materials are special type of energy conversion materials that link mechanical characteristics with electrical characteristics, shunt circuits coupled with such materials play a key role in the wave propagation and/or vibration control performance in smart periodic structures. Conventional shunt circuit designs utilize resistive shunt (R-shunt) and resonant shunt (RL-shunt). More recently, semi-passive nonlinear approaches have also been developed for efficiently controlling the vibrations of such structures. In this paper, an innovative smart periodic beam structure with nonlinear interleaved-switched electric networks based on synchronized switching damping on inductor (SSDI) is proposed and investigated for vibration reduction and wave propagation attenuation. Different from locally resonant band gap mechanism forming narrow band gaps around the desired resonant frequencies, the proposed interleaved electrical networks can induce new broadly low-frequency stop bands and broaden primitive Bragg stop bands by virtue of unique interleaved electrical configurations and the SSDI technique which has the unique feature of realizing automatic impedance adaptation with a small inductance. Finite element modeling of a Timoshenko electromechanical beam structure is also presented for validating dispersion properties of the structure. Both theoretical and experimental results demonstrate that the proposed beam structure not only shows better vibration and wave propagation attenuation than the smart beam structure with independent switched networks, but also has technical simplicity of requiring only half of the number of switches than the independent switched network needs.

A distributed approach to the OPF problem

NASA Astrophysics Data System (ADS)

Erseghe, Tomaso

2015-12-01

This paper presents a distributed approach to optimal power flow (OPF) in an electrical network, suitable for application in a future smart grid scenario where access to resource and control is decentralized. The non-convex OPF problem is solved by an augmented Lagrangian method, similar to the widely known ADMM algorithm, with the key distinction that penalty parameters are constantly increased. A (weak) assumption on local solver reliability is required to always ensure convergence. A certificate of convergence to a local optimum is available in the case of bounded penalty parameters. For moderate sized networks (up to 300 nodes, and even in the presence of a severe partition of the network), the approach guarantees a performance very close to the optimum, with an appreciably fast convergence speed. The generality of the approach makes it applicable to any (convex or non-convex) distributed optimization problem in networked form. In the comparison with the literature, mostly focused on convex SDP approximations, the chosen approach guarantees adherence to the reference problem, and it also requires a smaller local computational complexity effort.

Multi-agent coordination algorithms for control of distributed energy resources in smart grids

NASA Astrophysics Data System (ADS)

Cortes, Andres

Sustainable energy is a top-priority for researchers these days, since electricity and transportation are pillars of modern society. Integration of clean energy technologies such as wind, solar, and plug-in electric vehicles (PEVs), is a major engineering challenge in operation and management of power systems. This is due to the uncertain nature of renewable energy technologies and the large amount of extra load that PEVs would add to the power grid. Given the networked structure of a power system, multi-agent control and optimization strategies are natural approaches to address the various problems of interest for the safe and reliable operation of the power grid. The distributed computation in multi-agent algorithms addresses three problems at the same time: i) it allows for the handling of problems with millions of variables that a single processor cannot compute, ii) it allows certain independence and privacy to electricity customers by not requiring any usage information, and iii) it is robust to localized failures in the communication network, being able to solve problems by simply neglecting the failing section of the system. We propose various algorithms to coordinate storage, generation, and demand resources in a power grid using multi-agent computation and decentralized decision making. First, we introduce a hierarchical vehicle-one-grid (V1G) algorithm for coordination of PEVs under usage constraints, where energy only flows from the grid in to the batteries of PEVs. We then present a hierarchical vehicle-to-grid (V2G) algorithm for PEV coordination that takes into consideration line capacity constraints in the distribution grid, and where energy flows both ways, from the grid in to the batteries, and from the batteries to the grid. Next, we develop a greedy-like hierarchical algorithm for management of demand response events with on/off loads. Finally, we introduce distributed algorithms for the optimal control of distributed energy resources, i.e., generation and storage in a microgrid. The algorithms we present are provably correct and tested in simulation. Each algorithm is assumed to work on a particular network topology, and simulation studies are carried out in order to demonstrate their convergence properties to a desired solution.

On-track testing of a power harvesting device for railroad track health monitoring

NASA Astrophysics Data System (ADS)

Hansen, Sean E.; Pourghodrat, Abolfazl; Nelson, Carl A.; Fateh, Mahmood

2010-03-01

A considerable proportion of railroad infrastructure exists in regions which are comparatively remote. With regard to the cost of extending electrical infrastructure into these areas, road crossings in these areas do not have warning light systems or crossing gates and are commonly marked with reflective signage. For railroad track health monitoring purposes, distributed sensor networks can be applicable in remote areas, but the same limitation regarding electrical infrastructure is the hindrance. This motivated the development of an energy harvesting solution for remote railroad deployment. This paper describes on-track experimental testing of a mechanical device for harvesting mechanical power from passing railcar traffic, in view of supplying electrical power to warning light systems at crossings and to remote networks of sensors. The device is mounted to and spans two rail ties and transforms the vertical rail displacement into electrical energy through mechanical amplification and rectification into a PMDC generator. A prototype was tested under loaded and unloaded railcar traffic at low speeds. Stress analysis and speed scaling analysis are presented, results of the on-track tests are compared and contrasted to previous laboratory testing, discrepancies between the two are explained, and conclusions are drawn regarding suitability of the device for illuminating high-efficiency LED lights at railroad crossings and powering track-health sensor networks.

Corticocortical evoked potentials reveal projectors and integrators in human brain networks.

PubMed

Keller, Corey J; Honey, Christopher J; Entz, Laszlo; Bickel, Stephan; Groppe, David M; Toth, Emilia; Ulbert, Istvan; Lado, Fred A; Mehta, Ashesh D

2014-07-02

The cerebral cortex is composed of subregions whose functional specialization is largely determined by their incoming and outgoing connections with each other. In the present study, we asked which cortical regions can exert the greatest influence over other regions and the cortical network as a whole. Previous research on this question has relied on coarse anatomy (mapping large fiber pathways) or functional connectivity (mapping inter-regional statistical dependencies in ongoing activity). Here we combined direct electrical stimulation with recordings from the cortical surface to provide a novel insight into directed, inter-regional influence within the cerebral cortex of awake humans. These networks of directed interaction were reproducible across strength thresholds and across subjects. Directed network properties included (1) a decrease in the reciprocity of connections with distance; (2) major projector nodes (sources of influence) were found in peri-Rolandic cortex and posterior, basal and polar regions of the temporal lobe; and (3) major receiver nodes (receivers of influence) were found in anterolateral frontal, superior parietal, and superior temporal regions. Connectivity maps derived from electrical stimulation and from resting electrocorticography (ECoG) correlations showed similar spatial distributions for the same source node. However, higher-level network topology analysis revealed differences between electrical stimulation and ECoG that were partially related to the reciprocity of connections. Together, these findings inform our understanding of large-scale corticocortical influence as well as the interpretation of functional connectivity networks. Copyright © 2014 the authors 0270-6474/14/349152-12$15.00/0.

Hydrogel Actuation by Electric Field Driven Effects

NASA Astrophysics Data System (ADS)

Morales, Daniel Humphrey

Hydrogels are networks of crosslinked, hydrophilic polymers capable of absorbing and releasing large amounts of water while maintaining their structural integrity. Polyelectrolyte hydrogels are a subset of hydrogels that contain ionizable moieties, which render the network sensitive to the pH and the ionic strength of the media and provide mobile counterions, which impart conductivity. These networks are part of a class of "smart" material systems that can sense and adjust their shape in response to the external environment. Hence, the ability to program and modulate hydrogel shape change has great potential for novel biomaterial and soft robotics applications. We utilized electric field driven effects to manipulate the interaction of ions within polyelectrolyte hydrogels in order to induce controlled deformation and patterning. Additionally, electric fields can be used to promote the interactions of separate gel networks, as modular components, and particle assemblies within gel networks to develop new types of soft composite systems. First, we present and analyze a walking gel actuator comprised of cationic and anionic gel legs attached by electric field-promoted polyion complexation. We characterize the electro-osmotic response of the hydrogels as a function of charge density and external salt concentration. The gel walkers achieve unidirectional motion on flat elastomer substrates and exemplify a simple way to move and manipulate soft matter devices in aqueous solutions. An 'ionoprinting' technique is presented with the capability to topographically structure and actuate hydrated gels in two and three dimensions by locally patterning ions induced by electric fields. The bound charges change the local mechanical properties of the gel to induce relief patterns and evoke localized stress, causing rapid folding in air. The ionically patterned hydrogels exhibit programmable temporal and spatial shape transitions which can be tuned by the duration and/or strength of the applied electric field. We extend the use of ionoprinting to develop multi-responsive bilayer gel systems capable of more complex shape transformation. The localized crosslinked regions determine the bending axis as the gel responds to the external environment. The bending can be tuned to reverse direction isothermally by changing the solvent quality or by changing the temperature at a fixed concentration. The multi-responsive behavior is caused by the volume transitions of a non-ionic, thermos-sensitive hydrogel coupled with a superabsorbent ionic hydrogel. Lastly, electric field driven microparticle assembly, using dielectrophoretic (DEP) forces, organized colloidal microparticles within a hydrogel matrix. The use of DEP forces enables rapid, efficient and precise control over the colloidal distribution. The resulting supracolloidal endoskeleton structures impart directional bending as the hydrogel shrinks. We compare the ordered particles structures to random particle distributions in affecting the hydrogel sheet bending response. This study demonstrates a universal technique for imparting directional properties in hydrogels towards new generations of hybrid soft materials.

A Distributed Prognostic Health Management Architecture

NASA Technical Reports Server (NTRS)

Bhaskar, Saha; Saha, Sankalita; Goebel, Kai

2009-01-01

This paper introduces a generic distributed prognostic health management (PHM) architecture with specific application to the electrical power systems domain. Current state-of-the-art PHM systems are mostly centralized in nature, where all the processing is reliant on a single processor. This can lead to loss of functionality in case of a crash of the central processor or monitor. Furthermore, with increases in the volume of sensor data as well as the complexity of algorithms, traditional centralized systems become unsuitable for successful deployment, and efficient distributed architectures are required. A distributed architecture though, is not effective unless there is an algorithmic framework to take advantage of its unique abilities. The health management paradigm envisaged here incorporates a heterogeneous set of system components monitored by a varied suite of sensors and a particle filtering (PF) framework that has the power and the flexibility to adapt to the different diagnostic and prognostic needs. Both the diagnostic and prognostic tasks are formulated as a particle filtering problem in order to explicitly represent and manage uncertainties; however, typically the complexity of the prognostic routine is higher than the computational power of one computational element ( CE). Individual CEs run diagnostic routines until the system variable being monitored crosses beyond a nominal threshold, upon which it coordinates with other networked CEs to run the prognostic routine in a distributed fashion. Implementation results from a network of distributed embedded devices monitoring a prototypical aircraft electrical power system are presented, where the CEs are Sun Microsystems Small Programmable Object Technology (SPOT) devices.

Modelling Framework and the Quantitative Analysis of Distributed Energy Resources in Future Distribution Networks

NASA Astrophysics Data System (ADS)

Han, Xue; Sandels, Claes; Zhu, Kun; Nordström, Lars

2013-08-01

There has been a large body of statements claiming that the large-scale deployment of Distributed Energy Resources (DERs) could eventually reshape the future distribution grid operation in numerous ways. Thus, it is necessary to introduce a framework to measure to what extent the power system operation will be changed by various parameters of DERs. This article proposed a modelling framework for an overview analysis on the correlation between DERs. Furthermore, to validate the framework, the authors described the reference models of different categories of DERs with their unique characteristics, comprising distributed generation, active demand and electric vehicles. Subsequently, quantitative analysis was made on the basis of the current and envisioned DER deployment scenarios proposed for Sweden. Simulations are performed in two typical distribution network models for four seasons. The simulation results show that in general the DER deployment brings in the possibilities to reduce the power losses and voltage drops by compensating power from the local generation and optimizing the local load profiles.

Workshop on Scientific Analysis and Policy in Network Security

DTIC Science & Technology

2010-09-10

IBBT Dcpt. Electrical Engineering-ESAT/COSlC. Kasteelpark Arenberg 10 Bus 2446, B-3001 Leuven. Belgium bart.preneelflesat.kuleuven.be Abstract. This...Bouissou1,3 1 Electricity de France R&D, 1 avenue du General de Gaulle, 92141 Clamart, France 2 Institut Telecom, Telecom ParisTech, 46 rue Barrault...for any x G Aj1; /, !,_0(x) is a probability distribution on AQ, such that if x G S{i then £jeS, (/’.^(.OXj) = L illul if x e Dii > then £j

The CAN Microcluster: Parallel Processing over the Controller Area Network

ERIC Educational Resources Information Center

Kuban, Paul A.; Ragade, Rammohan K.

2005-01-01

Most electrical engineering and computer science undergraduate programs include at least one course on microcontrollers and assembly language programming. Some departments offer legacy courses in C programming, but few include C programming from an embedded systems perspective, where it is still regularly used. Distributed computing and parallel…

Electrical Coupling between the Myenteric Interstitial Cells of Cajal and Adjacent Muscle Layers in the Guinea-Pig Gastric Antrum

PubMed Central

Cousins, H M; Edwards, F R; Hickey, H; Hill, C E; Hirst, G D S

2003-01-01

Intracellular recordings were made from short segments of the muscular wall of the guinea-pig gastric antrum. Preparations were impaled using two independent microelectrodes, one positioned in the circular layer and the other either in the longitudinal layer, in the network of myenteric interstitial cells of Cajal (ICCmy) or in the circular layer. Cells in each layer displayed characteristic patterns of rhythmical activity, with the largest signals being generated by ICCmy. Current pulses injected into the circular muscle layer produced electrotonic potentials in each cell layer, indicating that the layers are electrically interconnected. The amplitudes of these electrotonic potentials were largest in the circular layer and smallest in the longitudinal layer. An analysis of electrical coupling between the three layers suggests that although the cells in each layer are well coupled to neighbouring cells, the coupling between either muscle layer and the network of ICCmy is relatively poor. The electrical connections between ICCmy and the circular layer did not rectify. In parallel immunohistochemical studies, the distribution of the connexins Cx40, Cx43 and Cx45 within the antral wall was determined. Only Cx43 was detected; it was widely distributed on ICCmy and throughout the circular smooth muscle layer, being concentrated around ICCIM, but was less abundant in the circular muscle layer immediately adjacent to ICCmy. Although the electrophysiological studies indicate that smooth muscle cells in the longitudinal muscle layer are electrically coupled to each other, none of the connexins examined were detected in this layer. PMID:12844505

The active control strategy on the output power for photovoltaic-storage systems based on extended PQ-QV-PV Node

NASA Astrophysics Data System (ADS)

Xu, Chen; Zhou, Bao-Rong; Zhai, Jian-Wei; Zhang, Yong-Jun; Yi, Ying-Qi

2017-05-01

In order to solve the problem of voltage exceeding specified limits and improve the penetration of photovoltaic in distribution network, we can make full use of the active power regulation ability of energy storage(ES) and the reactive power regulation ability of grid-connected photovoltaic inverter to provide support of active power and reactive power for distribution network. A strategy of actively controlling the output power for photovoltaic-storage system based on extended PQ-QV-PV node by analyzing the voltage regulating mechanism of point of commom coupling(PCC) of photovoltaic with energy storage(PVES) by controlling photovoltaic inverter and energy storage. The strategy set a small wave range of voltage to every photovoltaic by making the type of PCC convert among PQ, PV and QV. The simulation results indicate that the active control method can provide a better solution to the problem of voltage exceeding specified limits when photovoltaic is connectted to electric distribution network.

Evaluation of water quality and stability in the drinking water distribution network in the Azogues city, Ecuador.

PubMed

García-Ávila, Fernando; Ramos-Fernández, Lía; Pauta, Damián; Quezada, Diego

2018-06-01

This document presents the physical-chemical parameters with the objective of evaluating and analyzing the drinking water quality in the Azogues city applying the water quality index (WQI) and to research the water stability in the distribution network using corrosion indexes. Thirty samples were collected monthly for six months throughout the drinking water distribution network; turbidity, temperature, electric conductivity, pH, total dissolved solids, total hardness, calcium, magnesium, alkalinity, chlorides, nitrates, sulfates and phosphates were determined; the physical-chemical parameters were measured using standard methods. The processed data revealed that the average values ​​of LSI, RSI and PSI were 0.5 (±0.34), 6.76 (±0.6), 6.50 (±0.99) respectively. The WQI calculation indicated that 100% of the samples are considered excellent quality water. According to the Langelier, Ryznar and Pukorius indexes showed that drinking water in Azogues is corrosive. The quality of drinking water according to the WQI is in a good and excellent category.

Optical sensors for electrical elements of a medium voltage distribution network

NASA Astrophysics Data System (ADS)

De Maria, Letizia; Bartalesi, Daniele; Serragli, Paolo; Paladino, Domenico

2012-04-01

The aging of most of the components of the National transmission and distribution system can potentially influence the reliability of power supply in a Medium Voltage (MV) network. In order to prevent possible dangerous situations, selected diagnostic indicators on electrical parts exploiting reliable and potentially low-cost sensors are required. This paper presents results concerning two main research activities regarding the development and application of innovative optical sensors for the diagnostic of MV electrical components. The first concerns a multi-sensor prototype for the detection of pre-discharges in MV switchboards: it is the combination of three different types of sensors operating simultaneously to detect incipient failure and to reduce the occurrence of false alarms. The system is real-time controlled by an embedded computer through a LabView interface. The second activity refers to a diagnostic tool to provide significant real-time information about early aging of MV/Low Voltage (LV) transformers by means of its vibration fingerprint. A miniaturized Optical Micro-Electro-Mechanical System (MEMS) based unit has been assembled for vibration measurements, wireless connected to a remote computer and controlled via LabView interface. Preliminary comparative tests were carried out with standard piezoelectric accelerometers on a conventional MV/LV test transformer under open circuit and in short-circuited configuration.

Analysis of Electric Vehicle Charging Impact on the Electric Power Grid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Zeming; Tian, Hao; Beshir, Mohammed J.

2016-09-24

In order to evaluate the impact of electric vehicles (EVs) on the distribution grid and assess their potential benefits to the future smart grid, it is crucial to study the EV charging patterns and the usage charging station. Though EVs are not yet widely adopted nationwide, a valuable methodology to conduct such studies is the statistical analysis of real-world charging data. This paper presents actual EV charging behavior of 64 EVs (5 brands, 8 models) from EV users and charging stations at Los Angeles Department of Water and Power for more than one year. Twenty-four-hour EV charging load curves havemore » been generated and studied for various load periods: daily, monthly, seasonally and yearly. Finally, the effect and impact of EV load on the California distribution network are evaluated at different EV penetration rates.« less

On the Dynamics of the Spontaneous Activity in Neuronal Networks

PubMed Central

Bonifazi, Paolo; Ruaro, Maria Elisabetta; Torre, Vincent

2007-01-01

Most neuronal networks, even in the absence of external stimuli, produce spontaneous bursts of spikes separated by periods of reduced activity. The origin and functional role of these neuronal events are still unclear. The present work shows that the spontaneous activity of two very different networks, intact leech ganglia and dissociated cultures of rat hippocampal neurons, share several features. Indeed, in both networks: i) the inter-spike intervals distribution of the spontaneous firing of single neurons is either regular or periodic or bursting, with the fraction of bursting neurons depending on the network activity; ii) bursts of spontaneous spikes have the same broad distributions of size and duration; iii) the degree of correlated activity increases with the bin width, and the power spectrum of the network firing rate has a 1/f behavior at low frequencies, indicating the existence of long-range temporal correlations; iv) the activity of excitatory synaptic pathways mediated by NMDA receptors is necessary for the onset of the long-range correlations and for the presence of large bursts; v) blockage of inhibitory synaptic pathways mediated by GABAA receptors causes instead an increase in the correlation among neurons and leads to a burst distribution composed only of very small and very large bursts. These results suggest that the spontaneous electrical activity in neuronal networks with different architectures and functions can have very similar properties and common dynamics. PMID:17502919

Research on information security system of waste terminal disposal process

NASA Astrophysics Data System (ADS)

Zhou, Chao; Wang, Ziying; Guo, Jing; Guo, Yajuan; Huang, Wei

2017-05-01

Informatization has penetrated the whole process of production and operation of electric power enterprises. It not only improves the level of lean management and quality service, but also faces severe security risks. The internal network terminal is the outermost layer and the most vulnerable node of the inner network boundary. It has the characteristics of wide distribution, long depth and large quantity. The user and operation and maintenance personnel technical level and security awareness is uneven, which led to the internal network terminal is the weakest link in information security. Through the implementation of security of management, technology and physics, we should establish an internal network terminal security protection system, so as to fully protect the internal network terminal information security.

The use of network theory to model disparate ship design information

NASA Astrophysics Data System (ADS)

Rigterink, Douglas; Piks, Rebecca; Singer, David J.

2014-06-01

This paper introduces the use of network theory to model and analyze disparate ship design information. This work will focus on a ship's distributed systems and their intra- and intersystem structures and interactions. The three system to be analyzed are: a passageway system, an electrical system, and a fire fighting system. These systems will be analyzed individually using common network metrics to glean information regarding their structures and attributes. The systems will also be subjected to community detection algorithms both separately and as a multiplex network to compare their similarities, differences, and interactions. Network theory will be shown to be useful in the early design stage due to its simplicity and ability to model any shipboard system.

A Study Using a Monte Carlo Method of the Optimal Configuration of a Distribution Network in Terms of Power Loss Sensing

PubMed Central

Moon, Hyun Ho; Lee, Jong Joo; Choi, Sang Yule; Cha, Jae Sang; Kang, Jang Mook; Kim, Jong Tae; Shin, Myong Chul

2011-01-01

Recently there have been many studies of power systems with a focus on “New and Renewable Energy” as part of “New Growth Engine Industry” promoted by the Korean government. “New And Renewable Energy”—especially focused on wind energy, solar energy and fuel cells that will replace conventional fossil fuels—is a part of the Power-IT Sector which is the basis of the SmartGrid. A SmartGrid is a form of highly-efficient intelligent electricity network that allows interactivity (two-way communications) between suppliers and consumers by utilizing information technology in electricity production, transmission, distribution and consumption. The New and Renewable Energy Program has been driven with a goal to develop and spread through intensive studies, by public or private institutions, new and renewable energy which, unlike conventional systems, have been operated through connections with various kinds of distributed power generation systems. Considerable research on smart grids has been pursued in the United States and Europe. In the United States, a variety of research activities on the smart power grid have been conducted within EPRI’s IntelliGrid research program. The European Union (EU), which represents Europe’s Smart Grid policy, has focused on an expansion of distributed generation (decentralized generation) and power trade between countries with improved environmental protection. Thus, there is current emphasis on a need for studies that assesses the economic efficiency of such distributed generation systems. In this paper, based on the cost of distributed power generation capacity, calculations of the best profits obtainable were made by a Monte Carlo simulation. Monte Carlo simulations that rely on repeated random sampling to compute their results take into account the cost of electricity production, daily loads and the cost of sales and generate a result faster than mathematical computations. In addition, we have suggested the optimal design, which considers the distribution loss associated with power distribution systems focus on sensing aspect and distributed power generation. PMID:22164047

High Current Ionic Diode Using Homogeneously Charged Asymmetric Nanochannel Network Membrane.

PubMed

Choi, Eunpyo; Wang, Cong; Chang, Gyu Tae; Park, Jungyul

2016-04-13

A high current ionic diode is achieved using an asymmetric nanochannel network membrane (NCNM) constructed by soft lithography and in situ self-assembly of nanoparticles with uniform surface charge. The asymmetric NCNM exhibits high rectified currents without losing a rectification ratio because of its ionic selectivity gradient and differentiated electrical conductance. Asymmetric ionic transport is analyzed with diode-like I-V curves and visualized via fluorescent dyes, which is closely correlated with ionic selectivity and ion distribution according to variation of NCNM geometries.

Testing of the box transformer 10/04.4 kV in the network of the electricity supply company

NASA Astrophysics Data System (ADS)

Cichowski, R.; Nickling, G.

1983-08-01

Applications of a 10/0.4 kV box transformer are studied. Single phase and triple phase prototypes were tested in a distribution network. Test results show that heat loss, hence ground desiccation danger is eliminated by using lean concrete as bedding material (ratio of weight sand: cement: water = 19:1:2). Redistribution of no-load losses and winding losses reduces the total loss from 460 to 324 W, and improves the connection technique.

Fuzzy-driven energy storage system for mitigating voltage unbalance factor on distribution network with photovoltaic system

NASA Astrophysics Data System (ADS)

Wong, Jianhui; Lim, Yun Seng; Morris, Stella; Morris, Ezra; Chua, Kein Huat

2017-04-01

The amount of small-scaled renewable energy sources is anticipated to increase on the low-voltage distribution networks for the improvement of energy efficiency and reduction of greenhouse gas emission. The growth of the PV systems on the low-voltage distribution networks can create voltage unbalance, voltage rise, and reverse-power flow. Usually these issues happen with little fluctuation. However, it tends to fluctuate severely as Malaysia is a region with low clear sky index. A large amount of clouds often passes over the country, hence making the solar irradiance to be highly scattered. Therefore, the PV power output fluctuates substantially. These issues can lead to the malfunction of the electronic based equipment, reduction in the network efficiency and improper operation of the power protection system. At the current practice, the amount of PV system installed on the distribution network is constraint by the utility company. As a result, this can limit the reduction of carbon footprint. Therefore, energy storage system is proposed as a solution for these power quality issues. To ensure an effective operation of the distribution network with PV system, a fuzzy control system is developed and implemented to govern the operation of an energy storage system. The fuzzy driven energy storage system is able to mitigate the fluctuating voltage rise and voltage unbalance on the electrical grid by actively manipulates the flow of real power between the grid and the batteries. To verify the effectiveness of the proposed fuzzy driven energy storage system, an experimental network integrated with 7.2kWp PV system was setup. Several case studies are performed to evaluate the response of the proposed solution to mitigate voltage rises, voltage unbalance and reduce the amount of reverse power flow under highly intermittent PV power output.

Real-time modeling and simulation of distribution feeder and distributed resources

NASA Astrophysics Data System (ADS)

Singh, Pawan

The analysis of the electrical system dates back to the days when analog network analyzers were used. With the advent of digital computers, many programs were written for power-flow and short circuit analysis for the improvement of the electrical system. Real-time computer simulations can answer many what-if scenarios in the existing or the proposed power system. In this thesis, the standard IEEE 13-Node distribution feeder is developed and validated on a real-time platform OPAL-RT. The concept and the challenges of the real-time simulation are studied and addressed. Distributed energy resources include some of the commonly used distributed generation and storage devices like diesel engine, solar photovoltaic array, and battery storage system are modeled and simulated on a real-time platform. A microgrid encompasses a portion of an electric power distribution which is located downstream of the distribution substation. Normally, the microgrid operates in paralleled mode with the grid; however, scheduled or forced isolation can take place. In such conditions, the microgrid must have the ability to operate stably and autonomously. The microgrid can operate in grid connected and islanded mode, both the operating modes are studied in the last chapter. Towards the end, a simple microgrid controller modeled and simulated on the real-time platform is developed for energy management and protection for the microgrid.

Extension algorithm for generic low-voltage networks

NASA Astrophysics Data System (ADS)

Marwitz, S.; Olk, C.

2018-02-01

Distributed energy resources (DERs) are increasingly penetrating the energy system which is driven by climate and sustainability goals. These technologies are mostly connected to low- voltage electrical networks and change the demand and supply situation in these networks. This can cause critical network states. Network topologies vary significantly and depend on several conditions including geography, historical development, network design or number of network connections. In the past, only some of these aspects were taken into account when estimating the network investment needs for Germany on the low-voltage level. Typically, fixed network topologies are examined or a Monte Carlo approach is used to quantify the investment needs at this voltage level. Recent research has revealed that DERs differ substantially between rural, suburban and urban regions. The low-voltage network topologies have different design concepts in these regions, so that different network topologies have to be considered when assessing the need for network extensions and investments due to DERs. An extension algorithm is needed to calculate network extensions and investment needs for the different typologies of generic low-voltage networks. We therefore present a new algorithm, which is capable of calculating the extension for generic low-voltage networks of any given topology based on voltage range deviations and thermal overloads. The algorithm requires information about line and cable lengths, their topology and the network state only. We test the algorithm on a radial, a loop, and a heavily meshed network. Here we show that the algorithm functions for electrical networks with these topologies. We found that the algorithm is able to extend different networks efficiently by placing cables between network nodes. The main value of the algorithm is that it does not require any information about routes for additional cables or positions for additional substations when it comes to estimating network extension needs.

Physics, stability, and dynamics of supply networks

NASA Astrophysics Data System (ADS)

Helbing, Dirk; Lämmer, Stefan; Seidel, Thomas; Šeba, Pétr; Płatkowski, Tadeusz

2004-12-01

We show how to treat supply networks as physical transport problems governed by balance equations and equations for the adaptation of production speeds. Although the nonlinear behavior is different, the linearized set of coupled differential equations is formally related to those of mechanical or electrical oscillator networks. Supply networks possess interesting features due to their complex topology and directed links. We derive analytical conditions for absolute and convective instabilities. The empirically observed “bullwhip effect” in supply chains is explained as a form of convective instability based on resonance effects. Moreover, it is generalized to arbitrary supply networks. Their related eigenvalues are usually complex, depending on the network structure (even without loops). Therefore, their generic behavior is characterized by damped or growing oscillations. We also show that regular distribution networks possess two negative eigenvalues only, but perturbations generate a spectrum of complex eigenvalues.

Study on Impact of Electric Vehicles Charging Models on Power Load

NASA Astrophysics Data System (ADS)

Cheng, Chen; Hui-mei, Yuan

2017-05-01

With the rapid increase in the number of electric vehicles, which will lead the power load on grid increased and have an adversely affect. This paper gives a detailed analysis of the following factors, such as scale of the electric cars, charging mode, initial charging time, initial state of charge, charging power and other factors. Monte Carlo simulation method is used to compare the two charging modes, which are conventional charging and fast charging, and MATLAB is used to model and simulate the electric vehicle charging load. The results show that compared with the conventional charging mode, fast charging mode can meet the requirements of fast charging, but also bring great load to the distribution network which will affect the reliability of power grid.

A Distribution Level Wide Area Monitoring System for the Electric Power Grid–FNET/GridEye

DOE PAGES

Liu, Yong; You, Shutang; Yao, Wenxuan; ...

2017-02-09

The wide area monitoring system (WAMS) is considered a pivotal component of future electric power grids. As a pilot WAMS that has been operated for more than a decade, the frequency monitoring network FNET/GridEye makes use of hundreds of global positioning system-synchronized phasor measurement sensors to capture the increasingly complicated grid behaviors across the interconnected power systems. In this paper, the FNET/GridEye system is overviewed and its operation experiences in electric power grid wide area monitoring are presented. Particularly, the implementation of a number of data analytics applications will be discussed in details. FNET/GridEye lays a firm foundation for themore » later WAMS operation in the electric power industry.« less

Will electrical cyber-physical interdependent networks undergo first-order transition under random attacks?

NASA Astrophysics Data System (ADS)

Ji, Xingpei; Wang, Bo; Liu, Dichen; Dong, Zhaoyang; Chen, Guo; Zhu, Zhenshan; Zhu, Xuedong; Wang, Xunting

2016-10-01

Whether the realistic electrical cyber-physical interdependent networks will undergo first-order transition under random failures still remains a question. To reflect the reality of Chinese electrical cyber-physical system, the "partial one-to-one correspondence" interdependent networks model is proposed and the connectivity vulnerabilities of three realistic electrical cyber-physical interdependent networks are analyzed. The simulation results show that due to the service demands of power system the topologies of power grid and its cyber network are highly inter-similar which can effectively avoid the first-order transition. By comparing the vulnerability curves between electrical cyber-physical interdependent networks and its single-layer network, we find that complex network theory is still useful in the vulnerability analysis of electrical cyber-physical interdependent networks.

Radar signal transmission and switching over optical networks

NASA Astrophysics Data System (ADS)

Esmail, Maged A.; Ragheb, Amr; Seleem, Hussein; Fathallah, Habib; Alshebeili, Saleh

2018-03-01

In this paper, we experimentally demonstrate a radar signal distribution over optical networks. The use of fiber enables us to distribute radar signals to distant sites with a low power loss. Moreover, fiber networks can reduce the radar system cost, by sharing precise and expensive radar signal generation and processing equipment. In order to overcome the bandwidth challenges in electrical switches, a semiconductor optical amplifier (SOA) is used as an all-optical device for wavelength conversion to the desired port (or channel) of a wavelength division multiplexing (WDM) network. Moreover, the effect of chromatic dispersion in double sideband (DSB) signals is combated by generating optical single sideband (OSSB) signals. The optimal values of the SOA device parameters required to generate an OSSB with a high sideband suppression ratio (SSR) are determined. We considered various parameters such as injection current, pump power, and probe power. In addition, the effect of signal wavelength conversion and transmission over fiber are studied in terms of signal dynamic range.

Robustness analysis of complex networks with power decentralization strategy via flow-sensitive centrality against cascading failures

NASA Astrophysics Data System (ADS)

Guo, Wenzhang; Wang, Hao; Wu, Zhengping

2018-03-01

Most existing cascading failure mitigation strategy of power grids based on complex network ignores the impact of electrical characteristics on dynamic performance. In this paper, the robustness of the power grid under a power decentralization strategy is analysed through cascading failure simulation based on AC flow theory. The flow-sensitive (FS) centrality is introduced by integrating topological features and electrical properties to help determine the siting of the generation nodes. The simulation results of the IEEE-bus systems show that the flow-sensitive centrality method is a more stable and accurate approach and can enhance the robustness of the network remarkably. Through the study of the optimal flow-sensitive centrality selection for different networks, we find that the robustness of the network with obvious small-world effect depends more on contribution of the generation nodes detected by community structure, otherwise, contribution of the generation nodes with important influence on power flow is more critical. In addition, community structure plays a significant role in balancing the power flow distribution and further slowing the propagation of failures. These results are useful in power grid planning and cascading failure prevention.

3D Carbon Nanotube Networks as Mechanical, Electrical and Photovoltaic Transducer and Superhydrophobic Filter

DTIC Science & Technology

2015-06-01

area throughout the entire 3D structure. Hydrogels, organogels, and aerogels based on silica [1] or Distribution A: Approved for public release...porosity materials (e.g. bulk carbon aerogels ) or aligned CNT arrays [3]. In addition, to test the capability of the system to respond to incident light

Random network model of electrical conduction in two-phase rock

NASA Astrophysics Data System (ADS)

Fuji-ta, Kiyoshi; Seki, Masayuki; Ichiki, Masahiro

2018-05-01

We developed a cell-type lattice model to clarify the interconnected conductivity mechanism of two-phase rock. We quantified electrical conduction networks in rock and evaluated electrical conductivity models of the two-phase interaction. Considering the existence ratio of conductive and resistive cells in the model, we generated natural matrix cells simulating a natural mineral distribution pattern, using Mersenne Twister random numbers. The most important and prominent feature of the model simulation is a drastic increase in the pseudo-conductivity index for conductor ratio R > 0.22. This index in the model increased from 10-4 to 100 between R = 0.22 and 0.9, a change of four orders of magnitude. We compared our model responses with results from previous model studies. Although the pseudo-conductivity computed by the model differs slightly from that of the previous model, model responses can account for the conductivity change. Our modeling is thus effective for quantitatively estimating the degree of interconnection of rock and minerals.

Power system voltage stability and agent based distribution automation in smart grid

NASA Astrophysics Data System (ADS)

Nguyen, Cuong Phuc

2011-12-01

Our interconnected electric power system is presently facing many challenges that it was not originally designed and engineered to handle. The increased inter-area power transfers, aging infrastructure, and old technologies, have caused many problems including voltage instability, widespread blackouts, slow control response, among others. These problems have created an urgent need to transform the present electric power system to a highly stable, reliable, efficient, and self-healing electric power system of the future, which has been termed "smart grid". This dissertation begins with an investigation of voltage stability in bulk transmission networks. A new continuation power flow tool for studying the impacts of generator merit order based dispatch on inter-area transfer capability and static voltage stability is presented. The load demands are represented by lumped load models on the transmission system. While this representation is acceptable in traditional power system analysis, it may not be valid in the future smart grid where the distribution system will be integrated with intelligent and quick control capabilities to mitigate voltage problems before they propagate into the entire system. Therefore, before analyzing the operation of the whole smart grid, it is important to understand the distribution system first. The second part of this dissertation presents a new platform for studying and testing emerging technologies in advanced Distribution Automation (DA) within smart grids. Due to the key benefits over the traditional centralized approach, namely flexible deployment, scalability, and avoidance of single-point-of-failure, a new distributed approach is employed to design and develop all elements of the platform. A multi-agent system (MAS), which has the three key characteristics of autonomy, local view, and decentralization, is selected to implement the advanced DA functions. The intelligent agents utilize a communication network for cooperation and negotiation. Communication latency is modeled using a user-defined probability density function. Failure-tolerant communication strategies are developed for agent communications. Major elements of advanced DA are developed in a completely distributed way and successfully tested for several IEEE standard systems, including: Fault Detection, Location, Isolation, and Service Restoration (FLISR); Coordination of Distributed Energy Storage Systems (DES); Distributed Power Flow (DPF); Volt-VAR Control (VVC); and Loss Reduction (LR).

Power System Information Delivering System Based on Distributed Object

NASA Astrophysics Data System (ADS)

Tanaka, Tatsuji; Tsuchiya, Takehiko; Tamura, Setsuo; Seki, Tomomichi; Kubota, Kenji

In recent years, improvement in computer performance and development of computer network technology or the distributed information processing technology has a remarkable thing. Moreover, the deregulation is starting and will be spreading in the electric power industry in Japan. Consequently, power suppliers are required to supply low cost power with high quality services to customers. Corresponding to these movements the authors have been proposed SCOPE (System Configuration Of PowEr control system) architecture for distributed EMS/SCADA (Energy Management Systems / Supervisory Control and Data Acquisition) system based on distributed object technology, which offers the flexibility and expandability adapting those movements. In this paper, the authors introduce a prototype of the power system information delivering system, which was developed based on SCOPE architecture. This paper describes the architecture and the evaluation results of this prototype system. The power system information delivering system supplies useful power systems information such as electric power failures to the customers using Internet and distributed object technology. This system is new type of SCADA system which monitors failure of power transmission system and power distribution system with geographic information integrated way.

Detecting defective electrical components in heterogeneous infra-red images by spatial control charts

NASA Astrophysics Data System (ADS)

Jamshidieini, Bahman; Fazaee, Reza

2016-05-01

Distribution network components connect machines and other loads to electrical sources. If resistance or current of any component is more than specified range, its temperature may exceed the operational limit which can cause major problems. Therefore, these defects should be found and eliminated according to their severity. Although infra-red cameras have been used for inspection of electrical components, maintenance prioritization of distribution cubicles is mostly based on personal perception and lack of training data prevents engineers from developing image processing methods. New research on the spatial control chart encouraged us to use statistical approaches instead of the pattern recognition for the image processing. In the present study, a new scanning pattern which can tolerate heavy autocorrelation among adjacent pixels within infra-red image was developed and for the first time combination of kernel smoothing, spatial control charts and local robust regression were used for finding defects within heterogeneous infra-red images of old distribution cubicles. This method does not need training data and this advantage is crucially important when the training data is not available.

Fair Energy Scheduling for Vehicle-to-Grid Networks Using Adaptive Dynamic Programming.

PubMed

Xie, Shengli; Zhong, Weifeng; Xie, Kan; Yu, Rong; Zhang, Yan

2016-08-01

Research on the smart grid is being given enormous supports worldwide due to its great significance in solving environmental and energy crises. Electric vehicles (EVs), which are powered by clean energy, are adopted increasingly year by year. It is predictable that the huge charge load caused by high EV penetration will have a considerable impact on the reliability of the smart grid. Therefore, fair energy scheduling for EV charge and discharge is proposed in this paper. By using the vehicle-to-grid technology, the scheduler controls the electricity loads of EVs considering fairness in the residential distribution network. We propose contribution-based fairness, in which EVs with high contributions have high priorities to obtain charge energy. The contribution value is defined by both the charge/discharge energy and the timing of the action. EVs can achieve higher contribution values when discharging during the load peak hours. However, charging during this time will decrease the contribution values seriously. We formulate the fair energy scheduling problem as an infinite-horizon Markov decision process. The methodology of adaptive dynamic programming is employed to maximize the long-term fairness by processing online network training. The numerical results illustrate that the proposed EV energy scheduling is able to mitigate and flatten the peak load in the distribution network. Furthermore, contribution-based fairness achieves a fast recovery of EV batteries that have deeply discharged and guarantee fairness in the full charge time of all EVs.

Nonlinear inversion of electrical resistivity imaging using pruning Bayesian neural networks

NASA Astrophysics Data System (ADS)

Jiang, Fei-Bo; Dai, Qian-Wei; Dong, Li

2016-06-01

Conventional artificial neural networks used to solve electrical resistivity imaging (ERI) inversion problem suffer from overfitting and local minima. To solve these problems, we propose to use a pruning Bayesian neural network (PBNN) nonlinear inversion method and a sample design method based on the K-medoids clustering algorithm. In the sample design method, the training samples of the neural network are designed according to the prior information provided by the K-medoids clustering results; thus, the training process of the neural network is well guided. The proposed PBNN, based on Bayesian regularization, is used to select the hidden layer structure by assessing the effect of each hidden neuron to the inversion results. Then, the hyperparameter α k , which is based on the generalized mean, is chosen to guide the pruning process according to the prior distribution of the training samples under the small-sample condition. The proposed algorithm is more efficient than other common adaptive regularization methods in geophysics. The inversion of synthetic data and field data suggests that the proposed method suppresses the noise in the neural network training stage and enhances the generalization. The inversion results with the proposed method are better than those of the BPNN, RBFNN, and RRBFNN inversion methods as well as the conventional least squares inversion.

The governance of innovation diffusion - a socio-technical analysis of energy policy

NASA Astrophysics Data System (ADS)

Nolden, C.

2012-10-01

This paper describes a dynamic price mechanism to coordinate eletric power generation from micro Combined Heat and Power (micro-CHP) systems in a network of households. It is assumed that the households are prosumers, i.e. both producers and consumers of electricity. The control is done on household level in a completely distributed manner. Avoiding a centralized controller both eases computation complexity and preserves communication structure in the network. Local information is used to decide to turn on or off the micro-CHP, but through price signals between the prosumers the network as a whole operates in a cooperative way.

Splitting nodes and linking channels: A method for assembling biocircuits from stochastic elementary units

NASA Astrophysics Data System (ADS)

Ferwerda, Cameron; Lipan, Ovidiu

2016-11-01

Akin to electric circuits, we construct biocircuits that are manipulated by cutting and assembling channels through which stochastic information flows. This diagrammatic manipulation allows us to create a method which constructs networks by joining building blocks selected so that (a) they cover only basic processes; (b) it is scalable to large networks; (c) the mean and variance-covariance from the Pauli master equation form a closed system; and (d) given the initial probability distribution, no special boundary conditions are necessary to solve the master equation. The method aims to help with both designing new synthetic signaling pathways and quantifying naturally existing regulatory networks.

[Neuronal and synaptic properties: fundamentals of network plasticity].

PubMed

Le Masson, G

2000-02-01

Neurons, within the nervous system, are organized in different neural networks through synaptic connections. Two fundamental components are dynamically interacting in these functional units. The first one are the neurons themselves, and far from being simple action potential generators, they are capable of complex electrical integrative properties due to various types, number, distribution and modulation of voltage-gated ionic channels. The second elements are the synapses where a similar complexity and plasticity is found. Identifying both cellular and synaptic intrinsic properties is necessary to understand the links between neural networks behavior and physiological function, and is a useful step towards a better control of neurological diseases.

Simulation test beds for the space station electrical power system

NASA Technical Reports Server (NTRS)

Sadler, Gerald G.

1988-01-01

NASA Lewis Research Center and its prime contractor are responsible for developing the electrical power system on the space station. The power system will be controlled by a network of distributed processors. Control software will be verified, validated, and tested in hardware and software test beds. Current plans for the software test bed involve using real time and nonreal time simulations of the power system. This paper will discuss the general simulation objectives and configurations, control architecture, interfaces between simulator and controls, types of tests, and facility configurations.

Network integration of distributed power generation

NASA Astrophysics Data System (ADS)

Dondi, Peter; Bayoumi, Deia; Haederli, Christoph; Julian, Danny; Suter, Marco

The world-wide move to deregulation of the electricity and other energy markets, concerns about the environment, and advances in renewable and high efficiency technologies has led to major emphasis being placed on the use of small power generation units in a variety of forms. The paper reviews the position of distributed generation (DG, as these small units are called in comparison with central power plants) with respect to the installation and interconnection of such units with the classical grid infrastructure. In particular, the status of technical standards both in Europe and USA, possible ways to improve the interconnection situation, and also the need for decisions that provide a satisfactory position for the network operator (who remains responsible for the grid, its operation, maintenance and investment plans) are addressed.

Optimal planning and design of a renewable energy based supply system for microgrids

DOE PAGES

Hafez, Omar; Bhattacharya, Kankar

2012-03-03

This paper presents a technique for optimal planning and design of hybrid renewable energy systems for microgrid applications. The Distributed Energy Resources Customer Adoption Model (DER-CAM) is used to determine the optimal size and type of distributed energy resources (DERs) and their operating schedules for a sample utility distribution system. Using the DER-CAM results, an evaluation is performed to evaluate the electrical performance of the distribution circuit if the DERs selected by the DER-CAM optimization analyses are incorporated. Results of analyses regarding the economic benefits of utilizing the optimal locations identified for the selected DER within the system are alsomore » presented. The actual Brookhaven National Laboratory (BNL) campus electrical network is used as an example to show the effectiveness of this approach. The results show that these technical and economic analyses of hybrid renewable energy systems are essential for the efficient utilization of renewable energy resources for microgird applications.« less

Study on Improving Partial Load by Connecting Geo-thermal Heat Pump System to Fuel Cell Network

NASA Astrophysics Data System (ADS)

Obara, Shinya; Kudo, Kazuhiko

Hydrogen piping, the electric power line, and exhaust heat recovery piping of the distributed fuel cells are connected with network, and operational planning is carried out. Reduction of the efficiency in partial load is improved by operation of the geo-thermal heat pump linked to the fuel cell network. The energy demand pattern of the individual houses in Sapporo was introduced. And the analysis method aiming at minimization of the fuel rate by the genetic algorithm was described. The fuel cell network system of an analysis example assumed connecting the fuel cell co-generation of five houses. When geo-thermal heat pump was introduced into fuel cell network system stated in this paper, fuel consumption was reduced 6% rather than the conventional method

Anti-correlations in the degree distribution increase stimulus detection performance in noisy spiking neural networks.

PubMed

Martens, Marijn B; Houweling, Arthur R; E Tiesinga, Paul H

2017-02-01

Neuronal circuits in the rodent barrel cortex are characterized by stable low firing rates. However, recent experiments show that short spike trains elicited by electrical stimulation in single neurons can induce behavioral responses. Hence, the underlying neural networks provide stability against internal fluctuations in the firing rate, while simultaneously making the circuits sensitive to small external perturbations. Here we studied whether stability and sensitivity are affected by the connectivity structure in recurrently connected spiking networks. We found that anti-correlation between the number of afferent (in-degree) and efferent (out-degree) synaptic connections of neurons increases stability against pathological bursting, relative to networks where the degrees were either positively correlated or uncorrelated. In the stable network state, stimulation of a few cells could lead to a detectable change in the firing rate. To quantify the ability of networks to detect the stimulation, we used a receiver operating characteristic (ROC) analysis. For a given level of background noise, networks with anti-correlated degrees displayed the lowest false positive rates, and consequently had the highest stimulus detection performance. We propose that anti-correlation in the degree distribution may be a computational strategy employed by sensory cortices to increase the detectability of external stimuli. We show that networks with anti-correlated degrees can in principle be formed by applying learning rules comprised of a combination of spike-timing dependent plasticity, homeostatic plasticity and pruning to networks with uncorrelated degrees. To test our prediction we suggest a novel experimental method to estimate correlations in the degree distribution.

Data processing of high-rate low-voltage distribution grid recordings for smart grid monitoring and analysis

NASA Astrophysics Data System (ADS)

Maaß, Heiko; Cakmak, Hüseyin Kemal; Bach, Felix; Mikut, Ralf; Harrabi, Aymen; Süß, Wolfgang; Jakob, Wilfried; Stucky, Karl-Uwe; Kühnapfel, Uwe G.; Hagenmeyer, Veit

2015-12-01

Power networks will change from a rigid hierarchic architecture to dynamic interconnected smart grids. In traditional power grids, the frequency is the controlled quantity to maintain supply and load power balance. Thereby, high rotating mass inertia ensures for stability. In the future, system stability will have to rely more on real-time measurements and sophisticated control, especially when integrating fluctuating renewable power sources or high-load consumers like electrical vehicles to the low-voltage distribution grid.

Effects of the distribution density of a biomass combined heat and power plant network on heat utilisation efficiency in village-town systems.

PubMed

Zhang, Yifei; Kang, Jian

2017-11-01

The building of biomass combined heat and power (CHP) plants is an effective means of developing biomass energy because they can satisfy demands for winter heating and electricity consumption. The purpose of this study was to analyse the effect of the distribution density of a biomass CHP plant network on heat utilisation efficiency in a village-town system. The distribution density is determined based on the heat transmission threshold, and the heat utilisation efficiency is determined based on the heat demand distribution, heat output efficiency, and heat transmission loss. The objective of this study was to ascertain the optimal value for the heat transmission threshold using a multi-scheme comparison based on an analysis of these factors. To this end, a model of a biomass CHP plant network was built using geographic information system tools to simulate and generate three planning schemes with different heat transmission thresholds (6, 8, and 10 km) according to the heat demand distribution. The heat utilisation efficiencies of these planning schemes were then compared by calculating the gross power, heat output efficiency, and heat transmission loss of the biomass CHP plant for each scenario. This multi-scheme comparison yielded the following results: when the heat transmission threshold was low, the distribution density of the biomass CHP plant network was high and the biomass CHP plants tended to be relatively small. In contrast, when the heat transmission threshold was high, the distribution density of the network was low and the biomass CHP plants tended to be relatively large. When the heat transmission threshold was 8 km, the distribution density of the biomass CHP plant network was optimised for efficient heat utilisation. To promote the development of renewable energy sources, a planning scheme for a biomass CHP plant network that maximises heat utilisation efficiency can be obtained using the optimal heat transmission threshold and the nonlinearity coefficient for local roads. Copyright © 2017 Elsevier Ltd. All rights reserved.

Smart-DS: Synthetic Models for Advanced, Realistic Testing: Distribution Systems and Scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishnan, Venkat K; Palmintier, Bryan S; Hodge, Brian S

The National Renewable Energy Laboratory (NREL) in collaboration with Massachusetts Institute of Technology (MIT), Universidad Pontificia Comillas (Comillas-IIT, Spain) and GE Grid Solutions, is working on an ARPA-E GRID DATA project, titled Smart-DS, to create: 1) High-quality, realistic, synthetic distribution network models, and 2) Advanced tools for automated scenario generation based on high-resolution weather data and generation growth projections. Through these advancements, the Smart-DS project is envisioned to accelerate the development, testing, and adoption of advanced algorithms, approaches, and technologies for sustainable and resilient electric power systems, especially in the realm of U.S. distribution systems. This talk will present themore » goals and overall approach of the Smart-DS project, including the process of creating the synthetic distribution datasets using reference network model (RNM) and the comprehensive validation process to ensure network realism, feasibility, and applicability to advanced use cases. The talk will provide demonstrations of early versions of synthetic models, along with the lessons learnt from expert engagements to enhance future iterations. Finally, the scenario generation framework, its development plans, and co-ordination with GRID DATA repository teams to house these datasets for public access will also be discussed.« less

Alternative Fuels Data Center: Electric Vehicle Charging Network Expands at

Science.gov Websites

National Parks Electric Vehicle Charging Network Expands at National Parks to someone by E-mail Share Alternative Fuels Data Center: Electric Vehicle Charging Network Expands at National Parks on Facebook Tweet about Alternative Fuels Data Center: Electric Vehicle Charging Network Expands at National

Basic Principles of Electrical Network Reliability Optimization in Liberalised Electricity Market

NASA Astrophysics Data System (ADS)

Oleinikova, I.; Krishans, Z.; Mutule, A.

2008-01-01

The authors propose to select long-term solutions to the reliability problems of electrical networks in the stage of development planning. The guide lines or basic principles of such optimization are: 1) its dynamical nature; 2) development sustainability; 3) integrated solution of the problems of network development and electricity supply reliability; 4) consideration of information uncertainty; 5) concurrent consideration of the network and generation development problems; 6) application of specialized information technologies; 7) definition of requirements for independent electricity producers. In the article, the major aspects of liberalized electricity market, its functions and tasks are reviewed, with emphasis placed on the optimization of electrical network development as a significant component of sustainable management of power systems.

Utilities bullish on meter-reading technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garner, W.L.

1995-01-15

By the end of 1996, the 400,000 customers of Kansas City Power & Light Company (KCPL) will have their electric meters read by a real-time wireless network that will relay electrical consumption readings back to computers at the utility`s customer service office. KCPL`s executives believe the new radio and cellular network will greatly improve the company`s ability to control its power distribution, manage its load requirements, monitor outages, and in the near future, allow time-of-use and offpeak pricing. The KCPL system represents the first systemwide, commercial application of wireless automated meter reading (AMR) by a U.S. utility. The article alsomore » describes other AMR systems for reading water and gas meters, along with saying that $18 billion in future power plant investments can be avoided by using time-of-use pricing for residential customers.« less

Variable synaptic strengths controls the firing rate distribution in feedforward neural networks.

PubMed

Ly, Cheng; Marsat, Gary

2018-02-01

Heterogeneity of firing rate statistics is known to have severe consequences on neural coding. Recent experimental recordings in weakly electric fish indicate that the distribution-width of superficial pyramidal cell firing rates (trial- and time-averaged) in the electrosensory lateral line lobe (ELL) depends on the stimulus, and also that network inputs can mediate changes in the firing rate distribution across the population. We previously developed theoretical methods to understand how two attributes (synaptic and intrinsic heterogeneity) interact and alter the firing rate distribution in a population of integrate-and-fire neurons with random recurrent coupling. Inspired by our experimental data, we extend these theoretical results to a delayed feedforward spiking network that qualitatively capture the changes of firing rate heterogeneity observed in in-vivo recordings. We demonstrate how heterogeneous neural attributes alter firing rate heterogeneity, accounting for the effect with various sensory stimuli. The model predicts how the strength of the effective network connectivity is related to intrinsic heterogeneity in such delayed feedforward networks: the strength of the feedforward input is positively correlated with excitability (threshold value for spiking) when firing rate heterogeneity is low and is negatively correlated with excitability with high firing rate heterogeneity. We also show how our theory can be used to predict effective neural architecture. We demonstrate that neural attributes do not interact in a simple manner but rather in a complex stimulus-dependent fashion to control neural heterogeneity and discuss how it can ultimately shape population codes.

Assessment of foetal exposure to the homogeneous magnetic field harmonic spectrum generated by electricity transmission and distribution networks.

PubMed

Fiocchi, Serena; Liorni, Ilaria; Parazzini, Marta; Ravazzani, Paolo

2015-04-01

During the last decades studies addressing the effects of exposure to Extremely Low Frequency Electromagnetic Fields (ELF-EMF) have pointed out a possible link between those fields emitted by power lines and childhood leukaemia. They have also stressed the importance of also including in the assessment the contribution of frequency components, namely harmonics, other than the fundamental one. Based on the spectrum of supply voltage networks allowed by the European standard for electricity quality assessment, in this study the exposure of high-resolution three-dimensional models of foetuses to the whole harmonic content of a uniform magnetic field with a fundamental frequency of 50 Hz, was assessed. The results show that the main contribution in terms of induced electric fields to the foetal exposure is given by the fundamental frequency component. The harmonic components add some contributions to the overall level of electric fields, however, due to the extremely low permitted amplitude of the harmonic components with respect to the fundamental, their amplitudes are low. The level of the induced electric field is also much lower than the limits suggested by the guidelines for general public exposure, when the amplitude of the incident magnetic field is set at the maximum permitted level.

A cardiac electrical activity model based on a cellular automata system in comparison with neural network model.

PubMed

Khan, Muhammad Sadiq Ali; Yousuf, Sidrah

2016-03-01

Cardiac Electrical Activity is commonly distributed into three dimensions of Cardiac Tissue (Myocardium) and evolves with duration of time. The indicator of heart diseases can occur randomly at any time of a day. Heart rate, conduction and each electrical activity during cardiac cycle should be monitor non-invasively for the assessment of "Action Potential" (regular) and "Arrhythmia" (irregular) rhythms. Many heart diseases can easily be examined through Automata model like Cellular Automata concepts. This paper deals with the different states of cardiac rhythms using cellular automata with the comparison of neural network also provides fast and highly effective stimulation for the contraction of cardiac muscles on the Atria in the result of genesis of electrical spark or wave. The specific formulated model named as "States of automaton Proposed Model for CEA (Cardiac Electrical Activity)" by using Cellular Automata Methodology is commonly shows the three states of cardiac tissues conduction phenomena (i) Resting (Relax and Excitable state), (ii) ARP (Excited but Absolutely refractory Phase i.e. Excited but not able to excite neighboring cells) (iii) RRP (Excited but Relatively Refractory Phase i.e. Excited and able to excite neighboring cells). The result indicates most efficient modeling with few burden of computation and it is Action Potential during the pumping of blood in cardiac cycle.

Assessment of Foetal Exposure to the Homogeneous Magnetic Field Harmonic Spectrum Generated by Electricity Transmission and Distribution Networks

PubMed Central

Fiocchi, Serena; Liorni, Ilaria; Parazzini, Marta; Ravazzani, Paolo

2015-01-01

During the last decades studies addressing the effects of exposure to Extremely Low Frequency Electromagnetic Fields (ELF-EMF) have pointed out a possible link between those fields emitted by power lines and childhood leukaemia. They have also stressed the importance of also including in the assessment the contribution of frequency components, namely harmonics, other than the fundamental one. Based on the spectrum of supply voltage networks allowed by the European standard for electricity quality assessment, in this study the exposure of high-resolution three-dimensional models of foetuses to the whole harmonic content of a uniform magnetic field with a fundamental frequency of 50 Hz, was assessed. The results show that the main contribution in terms of induced electric fields to the foetal exposure is given by the fundamental frequency component. The harmonic components add some contributions to the overall level of electric fields, however, due to the extremely low permitted amplitude of the harmonic components with respect to the fundamental, their amplitudes are low. The level of the induced electric field is also much lower than the limits suggested by the guidelines for general public exposure, when the amplitude of the incident magnetic field is set at the maximum permitted level. PMID:25837346

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Ching-Yen; Shepelev, Aleksey; Qiu, Charlie

With an increased number of Electric Vehicles (EVs) on the roads, charging infrastructure is gaining an ever-more important role in simultaneously meeting the needs of the local distribution grid and of EV users. This paper proposes a mesh network RFID system for user identification and charging authorization as part of a smart charging infrastructure providing charge monitoring and control. The Zigbee-based mesh network RFID provides a cost-efficient solution to identify and authorize vehicles for charging and would allow EV charging to be conducted effectively while observing grid constraints and meeting the needs of EV drivers

Collegiate Cyber Defense Competition Effort

DTIC Science & Technology

2018-03-01

Energy – an electrical utility company. • 2016 : ODIN Security – a small aerospace and defense contracting firm Approved for Public Release...to secure supervisory control and data acquisition (SCADA) networks. Approved for Public Release; Distribution Unlimited 7 During the 2016 NCCDC...COLLEGIATE CYBER DEFENSE COMPETITION EFFORT UNIVERSITY OF TEXAS AT SAN ANTONIO MARCH 2018 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE

The harmonic impact of electric vehicle battery charging

NASA Astrophysics Data System (ADS)

Staats, Preston Trent

The potential widespread introduction of the electric vehicle (EV) presents both opportunities and challenges to the power systems engineers who will be required to supply power to EV batteries. One of the challenges associated with EV battery charging comes from the potentially high harmonic currents associated with the conversion of ac power system voltages to dc EV battery voltages. Harmonic currents lead to increased losses in distribution circuits and reduced life expectancy of such power distribution components as capacitors and transformers. Harmonic current injections also cause harmonic voltages on power distribution networks. These distorted voltages can affect power system loads and specific standards exist regulating acceptable voltage distortion. This dissertation develops and presents the theory required to evaluate the electric vehicle battery charger as a harmonic distorting load and its possible harmonic impact on various aspects of power distribution systems. The work begins by developing a method for evaluating the net harmonic current injection of a large collection of EV battery chargers which accounts for variation in the start-time and initial battery state-of-charge between individual chargers. Next, this method is analyzed to evaluate the effect of input parameter variation on the net harmonic currents predicted by the model. We then turn to an evaluation of the impact of EV charger harmonic currents on power distribution systems, first evaluating the impact of these currents on a substation transformer and then on power distribution system harmonic voltages. The method presented accounts for the uncertainty in EV harmonic current injections by modeling the start-time and initial battery state-of-charge (SOC) of an individual EV battery charger as random variables. Thus, the net harmonic current, and distribution system harmonic voltages are formulated in a stochastic framework. Results indicate that considering variation in start-time and SOC leads to reduced estimates of harmonic current injection when compared to more traditional methods that do not account for variation. Evaluation of power distribution system harmonic voltages suggests that for any power distribution network there is a definite threshold penetration of EVs, below which the total harmonic distortion of voltage exceeds 5% at an insignificant number of buses. Thus, most existing distribution systems will probably be able to accommodate the early introduction of EV battery charging without widespread harmonic voltage problems.

Probabilistic Harmonic Analysis on Distributed Photovoltaic Integration Considering Typical Weather Scenarios

NASA Astrophysics Data System (ADS)

Bin, Che; Ruoying, Yu; Dongsheng, Dang; Xiangyan, Wang

2017-05-01

Distributed Generation (DG) integrating to the network would cause the harmonic pollution which would cause damages on electrical devices and affect the normal operation of power system. On the other hand, due to the randomness of the wind and solar irradiation, the output of DG is random, too, which leads to an uncertainty of the harmonic generated by the DG. Thus, probabilistic methods are needed to analyse the impacts of the DG integration. In this work we studied the harmonic voltage probabilistic distribution and the harmonic distortion in distributed network after the distributed photovoltaic (DPV) system integrating in different weather conditions, mainly the sunny day, cloudy day, rainy day and the snowy day. The probabilistic distribution function of the DPV output power in different typical weather conditions could be acquired via the parameter identification method of maximum likelihood estimation. The Monte-Carlo simulation method was adopted to calculate the probabilistic distribution of harmonic voltage content at different frequency orders as well as the harmonic distortion (THD) in typical weather conditions. The case study was based on the IEEE33 system and the results of harmonic voltage content probabilistic distribution as well as THD in typical weather conditions were compared.

A decentralized approach to reducing the social costs of cascading failures

NASA Astrophysics Data System (ADS)

Hines, Paul

Large cascading failures in electrical power networks come with enormous social costs. These can be direct financial costs, such as the loss of refrigerated foods in grocery stores, or more indirect social costs, such as the traffic congestion that results from the failure of traffic signals. While engineers and policy makers have made numerous technical and organizational changes to reduce the frequency and impact of large cascading failures, the existing data, as described in Chapter 2 of this work, indicate that the overall frequency and impact of large electrical blackouts in the United States are not decreasing. Motivated by the cascading failure problem, this thesis describes a new method for Distributed Model Predictive Control and a power systems application. The central goal of the method, when applied to power systems, is to reduce the social costs of cascading failures by making small, targeted reductions in load and generation and changes to generator voltage set points. Unlike some existing schemes that operate from centrally located control centers, the method is operated by software agents located at substations distributed throughout the power network. The resulting multi-agent control system is a new approach to decentralized control, combining Distributed Model Predictive Control and Reciprocal Altruism. Experimental results indicate that this scheme can in fact decrease the average size, and thus social costs, of cascading failures. Over 100 randomly generated disturbances to a model of the IEEE 300 bus test network, the method resulted in nearly an order of magnitude decrease in average event size (measured in cost) relative to cascading failure simulations without remedial control actions. Additionally, the communication requirements for the method are measured, and found to be within the bandwidth capabilities of current communications technology (on the order of 100kB/second). Experiments on several resistor networks with varying structures, including a random graph, a scale-free network and a power grid indicate that the effectiveness of decentralized control schemes, like the method proposed here, is a function of the structure of the network that is to be controlled.

Geometric properties-dependent neural synchrony modulated by extracellular subthreshold electric field

NASA Astrophysics Data System (ADS)

Wei, Xile; Si, Kaili; Yi, Guosheng; Wang, Jiang; Lu, Meili

2016-07-01

In this paper, we use a reduced two-compartment neuron model to investigate the interaction between extracellular subthreshold electric field and synchrony in small world networks. It is observed that network synchronization is closely related to the strength of electric field and geometric properties of the two-compartment model. Specifically, increasing the electric field induces a gradual improvement in network synchrony, while increasing the geometric factor results in an abrupt decrease in synchronization of network. In addition, increasing electric field can make the network become synchronous from asynchronous when the geometric parameter is set to a given value. Furthermore, it is demonstrated that network synchrony can also be affected by the firing frequency and dynamical bifurcation feature of single neuron. These results highlight the effect of weak field on network synchrony from the view of biophysical model, which may contribute to further understanding the effect of electric field on network activity.

Structures with high number density of carbon nanotubes and 3-dimensional distribution

NASA Technical Reports Server (NTRS)

Chen, Zheng (Inventor); Tzeng, Yonhua (Inventor)

2002-01-01

A composite is described having a three dimensional distribution of carbon nanotubes. The critical aspect of such composites is a nonwoven network of randomly oriented fibers connected at their junctions to afford macropores in the spaces between the fibers. A variety of fibers may be employed, including metallic fibers, and especially nickel fibers. The composite has quite desirable properties for cold field electron emission applications, such as a relatively low turn-on electric field, high electric field enhancement factors, and high current densities. The composites of this invention also show favorable properties for other an electrode applications. Several methods, which also have general application in carbon nanotube production, of preparing these composites are described and employ a liquid feedstock of oxyhydrocarbons as carbon nanotube precursors.

Alternative Fuels Data Center: New York Broadens Network for Electric

Science.gov Websites

Vehicle Charging New York Broadens Network for Electric Vehicle Charging to someone by E-mail Share Alternative Fuels Data Center: New York Broadens Network for Electric Vehicle Charging on Facebook Tweet about Alternative Fuels Data Center: New York Broadens Network for Electric Vehicle Charging on

Global Electricity Trade Network: Structures and Implications

PubMed Central

Ji, Ling; Jia, Xiaoping; Chiu, Anthony S. F.; Xu, Ming

2016-01-01

Nations increasingly trade electricity, and understanding the structure of the global power grid can help identify nations that are critical for its reliability. This study examines the global grid as a network with nations as nodes and international electricity trade as links. We analyze the structure of the global electricity trade network and find that the network consists of four sub-networks, and provide a detailed analysis of the largest network, Eurasia. Russia, China, Ukraine, and Azerbaijan have high betweenness measures in the Eurasian sub-network, indicating the degrees of centrality of the positions they hold. The analysis reveals that the Eurasian sub-network consists of seven communities based on the network structure. We find that the communities do not fully align with geographical proximity, and that the present international electricity trade in the Eurasian sub-network causes an approximately 11 million additional tons of CO2 emissions. PMID:27504825

Global Electricity Trade Network: Structures and Implications.

PubMed

Ji, Ling; Jia, Xiaoping; Chiu, Anthony S F; Xu, Ming

2016-01-01

Nations increasingly trade electricity, and understanding the structure of the global power grid can help identify nations that are critical for its reliability. This study examines the global grid as a network with nations as nodes and international electricity trade as links. We analyze the structure of the global electricity trade network and find that the network consists of four sub-networks, and provide a detailed analysis of the largest network, Eurasia. Russia, China, Ukraine, and Azerbaijan have high betweenness measures in the Eurasian sub-network, indicating the degrees of centrality of the positions they hold. The analysis reveals that the Eurasian sub-network consists of seven communities based on the network structure. We find that the communities do not fully align with geographical proximity, and that the present international electricity trade in the Eurasian sub-network causes an approximately 11 million additional tons of CO2 emissions.

Statistical analysis of storm electrical discharges reconstituted from a lightning mapping system, a lightning location system, and an acoustic array

NASA Astrophysics Data System (ADS)

Gallin, Louis-Jonardan; Farges, Thomas; Marchiano, Régis; Coulouvrat, François; Defer, Eric; Rison, William; Schulz, Wolfgang; Nuret, Mathieu

2016-04-01

In the framework of the European Hydrological Cycle in the Mediterranean Experiment project, a field campaign devoted to the study of electrical activity during storms took place in the south of France in 2012. An acoustic station composed of four microphones and four microbarometers was deployed within the coverage of a Lightning Mapping Array network. On the 26 October 2012, a thunderstorm passed just over the acoustic station. Fifty-six natural thunder events, due to cloud-to-ground and intracloud flashes, were recorded. This paper studies the acoustic reconstruction, in the low frequency range from 1 to 40 Hz, of the recorded flashes and their comparison with detections from electromagnetic networks. Concurrent detections from the European Cooperation for Lightning Detection lightning location system were also used. Some case studies show clearly that acoustic signal from thunder comes from the return stroke but also from the horizontal discharges which occur inside the clouds. The huge amount of observation data leads to a statistical analysis of lightning discharges acoustically recorded. Especially, the distributions of altitudes of reconstructed acoustic detections are explored in detail. The impact of the distance to the source on these distributions is established. The capacity of the acoustic method to describe precisely the lower part of nearby cloud-to-ground discharges, where the Lightning Mapping Array network is not effective, is also highlighted.

An electrical betweenness approach for vulnerability assessment of power grids considering the capacity of generators and load

NASA Astrophysics Data System (ADS)

Wang, Kai; Zhang, Bu-han; Zhang, Zhe; Yin, Xiang-gen; Wang, Bo

2011-11-01

Most existing research on the vulnerability of power grids based on complex networks ignores the electrical characteristics and the capacity of generators and load. In this paper, the electrical betweenness is defined by considering the maximal demand of load and the capacity of generators in power grids. The loss of load, which reflects the ability of power grids to provide sufficient power to customers, is introduced to measure the vulnerability together with the size of the largest cluster. The simulation results of the IEEE-118 bus system and the Central China Power Grid show that the cumulative distributions of node electrical betweenness follow a power-law and that the nodes with high electrical betweenness play critical roles in both topological structure and power transmission of power grids. The results prove that the model proposed in this paper is effective for analyzing the vulnerability of power grids.

Electrical description of N2 capacitively coupled plasmas with the global model

NASA Astrophysics Data System (ADS)

Cao, Ming-Lu; Lu, Yi-Jia; Cheng, Jia; Ji, Lin-Hong; Engineering Design Team

2016-10-01

N2 discharges in a commercial capacitively coupled plasma reactor are modelled by a combination of an equivalent circuit and the global model, for a range of gas pressure at 1 4 Torr. The ohmic and inductive plasma bulk and the capacitive sheath are represented as LCR elements, with electrical characteristics determined by plasma parameters. The electron density and electron temperature are obtained from the global model in which a Maxwellian electron distribution is assumed. Voltages and currents are recorded by a VI probe installed after the match network. Using the measured voltage as an input, the current flowing through the discharge volume is calculated from the electrical model and shows excellent agreement with the measurements. The experimentally verified electrical model provides a simple and accurate description for the relationship between the external electrical parameters and the plasma properties, which can serve as a guideline for process window planning in industrial applications.

The electrical structure of lithosphere beneath Northeast China —Preliminary results from SinoProbe-01-04

NASA Astrophysics Data System (ADS)

Hui, F.; Qing, Z.; Gengen, Q.; Fagen, P.; Dawei, B.; Baotun, G.; Jingqi, L.; Changwang, L.; Xiaochang, L.; Meixing, H.; Bingrui, D.

2012-12-01

Being constituted by the Seberia, Northern China fossil plate and Pacific Plate, the tectonics of Northeast China are very complicated. In order to study the electrical structure in these areas, the project SinoProbe-01-04 'Experimental study of 'standard monitoring network' of continental EM parameters in Northeast China' have established a 4°×4°regional MT array covering the whole Northeast China(Fig. 1). To make sure that MT data observed on each standard point representatively, a cross profile with the standard point being center and eight auxiliary measuring points around has been designed in practical work, and the same direction of the physical measuring point should have 20 km space, the observation time should be more than 120 hours in standard point and more than 24 hours in each auxiliary station. Both broadband MT equipment (V5-2000) and long-period MT equipment (LEMI-417M) have been used together in standard point, then the ultra-wideband electromagnetic signals at 320HZ-1/10000Hz can be acquired by combining the field data observed by each equipment. Eleven MT standard network control point with total 99 physical measuring points have been finished in 2010, then those works were repeated again in 2011 to make sure observed result reliable. Based on the observed result, this article preliminary analysis the electrical structure of each major tectonic element in Northeast China, which including the regularity of distribution of regional electrical spindle, the distribution characteristics of vertical conductivity, development status of the low resistivity layer in the crust, and the depth of the high conductivity layer in upper mantle. It has been founded that the electrical features of the major tectonic element in Northeast China are different and appear electrical-heterogeneous in cross direction. Fig.1 MT array observed site

Conceptual study of superconducting urban area power systems

NASA Astrophysics Data System (ADS)

Noe, Mathias; Bach, Robert; Prusseit, Werner; Willén, Dag; Gold-acker, Wilfried; Poelchau, Juri; Linke, Christian

2010-06-01

Efficient transmission, distribution and usage of electricity are fundamental requirements for providing citizens, societies and economies with essential energy resources. It will be a major future challenge to integrate more sustainable generation resources, to meet growing electricity demand and to renew electricity networks. Research and development on superconducting equipment and components have an important role to play in addressing these challenges. Up to now, most studies on superconducting applications in power systems have been concentrated on the application of specific devices like for example cables and current limiters. In contrast to this, the main focus of our study is to show the consequence of a large scale integration of superconducting power equipment in distribution level urban power systems. Specific objectives are to summarize the state-of-the-art of superconducting power equipment including cooling systems and to compare the superconducting power system with respect to energy and economic efficiency with conventional solutions. Several scenarios were considered starting from the replacement of an existing distribution level sub-grid up to a full superconducting urban area distribution level power system. One major result is that a full superconducting urban area distribution level power system could be cost competitive with existing solutions in the future. In addition to that, superconducting power systems offer higher energy efficiency as well as a number of technical advantages like lower voltage drops and improved stability.

Harnessing Electrostatic Forces to Grow Bio-inspired Hierarchical Vascular Networks

NASA Astrophysics Data System (ADS)

Behler, Kristopher; Melrose, Zachary; Schott, Andrew; Wetzel, Eric

2012-02-01

Vascular networks provide a system for fluid distribution. Artificial vascular materials with enhanced properties are currently being developed that could ultimately be integrated into systems reliant upon fluid transport while retaining their structural properties. An uninterrupted and controllable supply of liquid is optimal for many applications such as continual self-healing materials, in-situ delivery of index matched fluids, thermal management and drug delivery systems could benefit from a bio-inspired vascular approach that combines complex network geometries with minimal processing parameters. Two such approaches to induce vascular networks are electrohydrodynamic viscous fingering (EHVF) and electrical treeing (ET). EHVF is a phenomenon that occurs when a low viscosity liquid is forced through a high viscosity fluid or matrix, resulting in branches due to capillary and viscous forces in the high viscosity material. By applying voltages of 0 -- 60 kV, finger diameter is reduced. ET is the result of partial discharges in a dielectric material. In the vicinity of a small diameter electrode, the local electric field is greater than the global dielectric strength, causing a localized, step-wise, breakdown to occur forming a highly branched interconnected structure. ET is a viable method to produce networks on a smaller, micron, scale than the products of the EHVF method.

A price mechanism for supply demand matching in local grid of households with micro-CHP

NASA Astrophysics Data System (ADS)

Larsen, G. K. H.; van Foreest, N. D.; Scherpen, J. M. A.

2012-10-01

This paper describes a dynamic price mechanism to coordinate eletric power generation from micro Combined Heat and Power (micro-CHP) systems in a network of households. It is assumed that the households are prosumers, i.e. both producers and consumers of electricity. The control is done on household level in a completely distributed manner. Avoiding a centralized controller both eases computation complexity and preserves communication structure in the network. Local information is used to decide to turn on or off the micro-CHP, but through price signals between the prosumers the network as a whole operates in a cooperative way.

Quantum dot-based local field imaging reveals plasmon-based interferometric logic in silver nanowire networks.

PubMed

Wei, Hong; Li, Zhipeng; Tian, Xiaorui; Wang, Zhuoxian; Cong, Fengzi; Liu, Ning; Zhang, Shunping; Nordlander, Peter; Halas, Naomi J; Xu, Hongxing

2011-02-09

We show that the local electric field distribution of propagating plasmons along silver nanowires can be imaged by coating the nanowires with a layer of quantum dots, held off the surface of the nanowire by a nanoscale dielectric spacer layer. In simple networks of silver nanowires with two optical inputs, control of the optical polarization and phase of the input fields directs the guided waves to a specific nanowire output. The QD-luminescent images of these structures reveal that a complete family of phase-dependent, interferometric logic functions can be performed on these simple networks. These results show the potential for plasmonic waveguides to support compact interferometric logic operations.

Exploring the Power Output of Small Wind Turbines in Urban San Antonio, Texas

NASA Astrophysics Data System (ADS)

Casillas, Jose; Sperduti, Stephanie; Cardenas, Rosa

2015-03-01

The means of transporting power from a centralized power plant by transmission lines has several disadvantages. Electricity transmission and distribution networks are costly, require long planning processes and are unsightly to residents. These networks are also susceptible to natural disasters creating massive disruptions to consumers. For these reasons distributed power sources such as solar panels and small wind turbines are becoming a more desirable and viable means of energy production. We report on the status of a study to determine the maximum output power of small wind turbines in urban San Antonio, Texas. Wind speed data along with power measurements from small wind turbines in urban San Antonio will be reported. U.S. Department of Education Title V HSI-STEM and Articulation Award No. P031C110145.

Design principles of electrical synaptic plasticity.

PubMed

O'Brien, John

2017-09-08

Essentially all animals with nervous systems utilize electrical synapses as a core element of communication. Electrical synapses, formed by gap junctions between neurons, provide rapid, bidirectional communication that accomplishes tasks distinct from and complementary to chemical synapses. These include coordination of neuron activity, suppression of voltage noise, establishment of electrical pathways that define circuits, and modulation of high order network behavior. In keeping with the omnipresent demand to alter neural network function in order to respond to environmental cues and perform tasks, electrical synapses exhibit extensive plasticity. In some networks, this plasticity can have dramatic effects that completely remodel circuits or remove the influence of certain cell types from networks. Electrical synaptic plasticity occurs on three distinct time scales, ranging from milliseconds to days, with different mechanisms accounting for each. This essay highlights principles that dictate the properties of electrical coupling within networks and the plasticity of the electrical synapses, drawing examples extensively from retinal networks. Copyright © 2017 The Author. Published by Elsevier B.V. All rights reserved.

The hearing ear is always found close to the speaking tongue: Review of the role of the motor system in speech perception.

PubMed

Skipper, Jeremy I; Devlin, Joseph T; Lametti, Daniel R

2017-01-01

Does "the motor system" play "a role" in speech perception? If so, where, how, and when? We conducted a systematic review that addresses these questions using both qualitative and quantitative methods. The qualitative review of behavioural, computational modelling, non-human animal, brain damage/disorder, electrical stimulation/recording, and neuroimaging research suggests that distributed brain regions involved in producing speech play specific, dynamic, and contextually determined roles in speech perception. The quantitative review employed region and network based neuroimaging meta-analyses and a novel text mining method to describe relative contributions of nodes in distributed brain networks. Supporting the qualitative review, results show a specific functional correspondence between regions involved in non-linguistic movement of the articulators, covertly and overtly producing speech, and the perception of both nonword and word sounds. This distributed set of cortical and subcortical speech production regions are ubiquitously active and form multiple networks whose topologies dynamically change with listening context. Results are inconsistent with motor and acoustic only models of speech perception and classical and contemporary dual-stream models of the organization of language and the brain. Instead, results are more consistent with complex network models in which multiple speech production related networks and subnetworks dynamically self-organize to constrain interpretation of indeterminant acoustic patterns as listening context requires. Copyright © 2016. Published by Elsevier Inc.

Electrical and mechanical tuning of a silicon vacancy defect in SiC for quantum information technology

NASA Astrophysics Data System (ADS)

Soykal, Oney O.; Reinecke, Thomas L.

We develop coherent control via Stark effect over the optical transition energies of silicon monovacancy deep center in hexagonal silicon carbide. We show that this defect's unique asymmetry properties of its piezoelectric tensor and Kramer's degenerate high-spin ground/excited state configurations can be used to create new possibilities in quantum information technology ranging from photonic networks to quantum key distribution. We also give examples of its qubit implementations via precise electric field control. This work was supported in part by ONR and by the Office of Secretary of Defense, Quantum Science and Engineering Program.

Estimation of electrical conductivity distribution within the human head from magnetic flux density measurement.

PubMed

Gao, Nuo; Zhu, S A; He, Bin

2005-06-07

We have developed a new algorithm for magnetic resonance electrical impedance tomography (MREIT), which uses only one component of the magnetic flux density to reconstruct the electrical conductivity distribution within the body. The radial basis function (RBF) network and simplex method are used in the present approach to estimate the conductivity distribution by minimizing the errors between the 'measured' and model-predicted magnetic flux densities. Computer simulations were conducted in a realistic-geometry head model to test the feasibility of the proposed approach. Single-variable and three-variable simulations were performed to estimate the brain-skull conductivity ratio and the conductivity values of the brain, skull and scalp layers. When SNR = 15 for magnetic flux density measurements with the target skull-to-brain conductivity ratio being 1/15, the relative error (RE) between the target and estimated conductivity was 0.0737 +/- 0.0746 in the single-variable simulations. In the three-variable simulations, the RE was 0.1676 +/- 0.0317. Effects of electrode position uncertainty were also assessed by computer simulations. The present promising results suggest the feasibility of estimating important conductivity values within the head from noninvasive magnetic flux density measurements.

Review of Supervisory Control and Data Acquisition (SCADA) Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reva Nickelson; Briam Johnson; Ken Barnes

2004-01-01

A review using open source information was performed to obtain data related to Supervisory Control and Data Acquisition (SCADA) systems used to supervise and control domestic electric power generation, transmission, and distribution. This report provides the technical details for the types of systems used, system disposal, cyber and physical security measures, network connections, and a gap analysis of SCADA security holes.

Energy Security of Army Installations & Islanding Methodologies

DTIC Science & Technology

2012-01-16

islanding of energy generation and distribution networks including electricity, natural gas , steam , liquid fuel, water, and others for the diverse...in geopolitics and war/peace/terrorism Breakthrough in reformation process of synthetic fuel production Hydrogen focused energy sector Oil and gas ...of synthetic AMf Q production Hydrogen focused energy sector D Of and gas remain available and cost-effective Natural Gas prices cut In

Creation of lumped parameter thermal model by the use of finite elements

NASA Technical Reports Server (NTRS)

1978-01-01

In the finite difference technique, the thermal network is represented by an analogous electrical network. The development of this network model, which is used to describe a physical system, often requires tedious and mental data preparation and checkout by the analyst which can be greatly reduced through the use of the computer programs to develop automatically the mathematical model and associated input data and graphically display the analytical model to facilitate model verification. Three separate programs are involved which are linked through common mass storage files and data card formats. These programs are SPAR, CINGEN and GEOMPLT, and are used to (1) develop thermal models for the MITAS II thermal analyzer program; (2) produce geometry plots of the thermal network; and (3) produce temperature distribution and time history plots.

Graphical models for optimal power flow

DOE PAGES

Dvijotham, Krishnamurthy; Chertkov, Michael; Van Hentenryck, Pascal; ...

2016-09-13

Optimal power flow (OPF) is the central optimization problem in electric power grids. Although solved routinely in the course of power grid operations, it is known to be strongly NP-hard in general, and weakly NP-hard over tree networks. In this paper, we formulate the optimal power flow problem over tree networks as an inference problem over a tree-structured graphical model where the nodal variables are low-dimensional vectors. We adapt the standard dynamic programming algorithm for inference over a tree-structured graphical model to the OPF problem. Combining this with an interval discretization of the nodal variables, we develop an approximation algorithmmore » for the OPF problem. Further, we use techniques from constraint programming (CP) to perform interval computations and adaptive bound propagation to obtain practically efficient algorithms. Compared to previous algorithms that solve OPF with optimality guarantees using convex relaxations, our approach is able to work for arbitrary tree-structured distribution networks and handle mixed-integer optimization problems. Further, it can be implemented in a distributed message-passing fashion that is scalable and is suitable for “smart grid” applications like control of distributed energy resources. In conclusion, numerical evaluations on several benchmark networks show that practical OPF problems can be solved effectively using this approach.« less

Network reliability maximization for stochastic-flow network subject to correlated failures using genetic algorithm and tabu\\xA0search

NASA Astrophysics Data System (ADS)

Yeh, Cheng-Ta; Lin, Yi-Kuei; Yang, Jo-Yun

2018-07-01

Network reliability is an important performance index for many real-life systems, such as electric power systems, computer systems and transportation systems. These systems can be modelled as stochastic-flow networks (SFNs) composed of arcs and nodes. Most system supervisors respect the network reliability maximization by finding the optimal multi-state resource assignment, which is one resource to each arc. However, a disaster may cause correlated failures for the assigned resources, affecting the network reliability. This article focuses on determining the optimal resource assignment with maximal network reliability for SFNs. To solve the problem, this study proposes a hybrid algorithm integrating the genetic algorithm and tabu search to determine the optimal assignment, called the hybrid GA-TS algorithm (HGTA), and integrates minimal paths, recursive sum of disjoint products and the correlated binomial distribution to calculate network reliability. Several practical numerical experiments are adopted to demonstrate that HGTA has better computational quality than several popular soft computing algorithms.

Future Roles of Milli-, Micro-, and Nano- Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marnay, Chris; Nordman, Bruce; Lai, Judy

Although it has slowed considerably, consumption of electricity continues to grow in developed economies. Further, there are some unknowns which might accelerate this growth, such as electrification of vehicle fleets and geothermal heat pump space and water heating. Most analysts anticipate that distributed energy resources (DER) will provide a large share of the expanded generation capacity required to meet this seemingly inexorably increasing electricity demand. Further, given the urgency of tackling the climate change problem, most of the added assets must be carbonfree renewables or nuclear, end-use efficiency improvements, or highly efficient fossil-fired technologies. In developed economies worldwide, the currentmore » power delivery paradigm has been in place for more than a century, i.e. since the emergence of polyphase AC systems around the turn of the last century. A key feature of this structure is that, in principle, universal service is delivered at a consistent level of power quality and reliability (PQR) throughout large regions. This paper describes a future possible structure for the electricity generation and delivery system that leaves the existing high voltage meshed grid paradigm in place, but involves radical reorganization of parts of the distribution network and customer sites. Managing a much more diverse dispersed system poses major challenges to the current centralized grid paradigm, particularly since many of these assets are small to tiny by macrogrid standards and they may ultimately number in the millions. They are also not ones that centralized control can rely upon to function in traditionally dependable ways, e.g. renewable generation can be highly variable and changes in output of generators are not independent. Although most involved in the industry agree that a paradigm shift is both necessary and desirable to manage the new system, the nature of the future system remains quite unclear. In the possible structure described here, the traditional grid, or macrogrid, remains similar at the high voltage meshed level. Three new entities are added more locally: community grids or milligrids that operate a segment of the existing distribution system, microgrids which are akin to current customer sites but which have automonous control, and nanogrids, such as telecom or Ethernet networks that currently distribute power to many low-power devices. The latter exist currently in the local electrical systems but are not typically considered a part of the traditional electricity supply system. Because all these new entities exhibit some localized control, providing appropriate local heterogeneous PQR becomes a possibility. These new grid concepts enable a more"bottom-up" approach to electricity distribution, in contrast to the historic 'top-down' model. The future will almost certainly include a mix of the two, but the balance among them and the interface (if any) between them is unclear.« less

Optimal Operation of Energy Storage in Power Transmission and Distribution

NASA Astrophysics Data System (ADS)

Akhavan Hejazi, Seyed Hossein

In this thesis, we investigate optimal operation of energy storage units in power transmission and distribution grids. At transmission level, we investigate the problem where an investor-owned independently-operated energy storage system seeks to offer energy and ancillary services in the day-ahead and real-time markets. We specifically consider the case where a significant portion of the power generated in the grid is from renewable energy resources and there exists significant uncertainty in system operation. In this regard, we formulate a stochastic programming framework to choose optimal energy and reserve bids for the storage units that takes into account the fluctuating nature of the market prices due to the randomness in the renewable power generation availability. At distribution level, we develop a comprehensive data set to model various stochastic factors on power distribution networks, with focus on networks that have high penetration of electric vehicle charging load and distributed renewable generation. Furthermore, we develop a data-driven stochastic model for energy storage operation at distribution level, where the distribution of nodal voltage and line power flow are modelled as stochastic functions of the energy storage unit's charge and discharge schedules. In particular, we develop new closed-form stochastic models for such key operational parameters in the system. Our approach is analytical and allows formulating tractable optimization problems. Yet, it does not involve any restricting assumption on the distribution of random parameters, hence, it results in accurate modeling of uncertainties. By considering the specific characteristics of random variables, such as their statistical dependencies and often irregularly-shaped probability distributions, we propose a non-parametric chance-constrained optimization approach to operate and plan energy storage units in power distribution girds. In the proposed stochastic optimization, we consider uncertainty from various elements, such as solar photovoltaic , electric vehicle chargers, and residential baseloads, in the form of discrete probability functions. In the last part of this thesis we address some other resources and concepts for enhancing the operation of power distribution and transmission systems. In particular, we proposed a new framework to determine the best sites, sizes, and optimal payment incentives under special contracts for committed-type DG projects to offset distribution network investment costs. In this framework, the aim is to allocate DGs such that the profit gained by the distribution company is maximized while each DG unit's individual profit is also taken into account to assure that private DG investment remains economical.

Estimation of electric fields and current from ground-based magnetometer data

NASA Technical Reports Server (NTRS)

Kamide, Y.; Richmond, A. D.

1984-01-01

Recent advances in numerical algorithms for estimating ionospheric electric fields and currents from groundbased magnetometer data are reviewed and evaluated. Tests of the adequacy of one such algorithm in reproducing large-scale patterns of electrodynamic parameters in the high-latitude ionosphere have yielded generally positive results, at least for some simple cases. Some encouraging advances in producing realistic conductivity models, which are a critical input, are pointed out. When the algorithms are applied to extensive data sets, such as the ones from meridian chain magnetometer networks during the IMS, together with refined conductivity models, unique information on instantaneous electric field and current patterns can be obtained. Examples of electric potentials, ionospheric currents, field-aligned currents, and Joule heating distributions derived from ground magnetic data are presented. Possible directions for future improvements are also pointed out.

Effects of nuclear electromagnetic pulse (EMP) on synchronous stability of the electric power system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manweiler, R.W.

1975-11-01

The effects of a nuclear electromagnetic pulse (EMP) on the synchronous stability of the electric power transmission and distribution systems are evaluated. The various modes of coupling of EMP to the power system are briefly discussed, with particular emphasis on those perturbations affecting the synchronous stability of the transmission system. A brief review of the fundamental concepts of the stability problem is given, with a discussion of the general characteristics of transient analysis. A model is developed to represent single sets as well as repetitive sets of multiple faults on the distribution systems, as might be produced by EMP. Themore » results of many numerical stability calculations are presented to illustrate the transmission system's response from different types of perturbations. The important parameters of both multiple and repetitive faults are studied, including the dependence of the response on the size of the perturbed area, the fault density, and the effective impedance between the fault location and the transmission system. Both major load reduction and the effect of the opening of tie lines at the time of perturbation are also studied. We conclude that there is a high probability that EMP can induce perturbations on the distribution networks causing a large portion of the transmission network in the perturbed area to lose synchronism. The result would be an immediate and massive power failure. (auth)« less

Abruptness of Cascade Failures in Power Grids

NASA Astrophysics Data System (ADS)

Pahwa, Sakshi; Scoglio, Caterina; Scala, Antonio

2014-01-01

Electric power-systems are one of the most important critical infrastructures. In recent years, they have been exposed to extreme stress due to the increasing demand, the introduction of distributed renewable energy sources, and the development of extensive interconnections. We investigate the phenomenon of abrupt breakdown of an electric power-system under two scenarios: load growth (mimicking the ever-increasing customer demand) and power fluctuations (mimicking the effects of renewable sources). Our results on real, realistic and synthetic networks indicate that increasing the system size causes breakdowns to become more abrupt; in fact, mapping the system to a solvable statistical-physics model indicates the occurrence of a first order transition in the large size limit. Such an enhancement for the systemic risk failures (black-outs) with increasing network size is an effect that should be considered in the current projects aiming to integrate national power-grids into ``super-grids''.

Abruptness of cascade failures in power grids.

PubMed

Pahwa, Sakshi; Scoglio, Caterina; Scala, Antonio

2014-01-15

Electric power-systems are one of the most important critical infrastructures. In recent years, they have been exposed to extreme stress due to the increasing demand, the introduction of distributed renewable energy sources, and the development of extensive interconnections. We investigate the phenomenon of abrupt breakdown of an electric power-system under two scenarios: load growth (mimicking the ever-increasing customer demand) and power fluctuations (mimicking the effects of renewable sources). Our results on real, realistic and synthetic networks indicate that increasing the system size causes breakdowns to become more abrupt; in fact, mapping the system to a solvable statistical-physics model indicates the occurrence of a first order transition in the large size limit. Such an enhancement for the systemic risk failures (black-outs) with increasing network size is an effect that should be considered in the current projects aiming to integrate national power-grids into "super-grids".

Abruptness of Cascade Failures in Power Grids

PubMed Central

Pahwa, Sakshi; Scoglio, Caterina; Scala, Antonio

2014-01-01

Electric power-systems are one of the most important critical infrastructures. In recent years, they have been exposed to extreme stress due to the increasing demand, the introduction of distributed renewable energy sources, and the development of extensive interconnections. We investigate the phenomenon of abrupt breakdown of an electric power-system under two scenarios: load growth (mimicking the ever-increasing customer demand) and power fluctuations (mimicking the effects of renewable sources). Our results on real, realistic and synthetic networks indicate that increasing the system size causes breakdowns to become more abrupt; in fact, mapping the system to a solvable statistical-physics model indicates the occurrence of a first order transition in the large size limit. Such an enhancement for the systemic risk failures (black-outs) with increasing network size is an effect that should be considered in the current projects aiming to integrate national power-grids into “super-grids”. PMID:24424239

Quantifying the Impact of Unavailability in Cyber-Physical Environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aissa, Anis Ben; Abercrombie, Robert K; Sheldon, Federick T.

2014-01-01

The Supervisory Control and Data Acquisition (SCADA) system discussed in this work manages a distributed control network for the Tunisian Electric & Gas Utility. The network is dispersed over a large geographic area that monitors and controls the flow of electricity/gas from both remote and centralized locations. The availability of the SCADA system in this context is critical to ensuring the uninterrupted delivery of energy, including safety, security, continuity of operations and revenue. Such SCADA systems are the backbone of national critical cyber-physical infrastructures. Herein, we propose adapting the Mean Failure Cost (MFC) metric for quantifying the cost of unavailability.more » This new metric combines the classic availability formulation with MFC. The resulting metric, so-called Econometric Availability (EA), offers a computational basis to evaluate a system in terms of the gain/loss ($/hour of operation) that affects each stakeholder due to unavailability.« less

Predictive modelling of grain-size distributions from marine electromagnetic profiling data using end-member analysis and a radial basis function network

NASA Astrophysics Data System (ADS)

Baasch, B.; Müller, H.; von Dobeneck, T.

2018-07-01

In this work, we present a new methodology to predict grain-size distributions from geophysical data. Specifically, electric conductivity and magnetic susceptibility of seafloor sediments recovered from electromagnetic profiling data are used to predict grain-size distributions along shelf-wide survey lines. Field data from the NW Iberian shelf are investigated and reveal a strong relation between the electromagnetic properties and grain-size distribution. The here presented workflow combines unsupervised and supervised machine-learning techniques. Non-negative matrix factorization is used to determine grain-size end-members from sediment surface samples. Four end-members were found, which well represent the variety of sediments in the study area. A radial basis function network modified for prediction of compositional data is then used to estimate the abundances of these end-members from the electromagnetic properties. The end-members together with their predicted abundances are finally back transformed to grain-size distributions. A minimum spatial variation constraint is implemented in the training of the network to avoid overfitting and to respect the spatial distribution of sediment patterns. The predicted models are tested via leave-one-out cross-validation revealing high prediction accuracy with coefficients of determination (R2) between 0.76 and 0.89. The predicted grain-size distributions represent the well-known sediment facies and patterns on the NW Iberian shelf and provide new insights into their distribution, transition and dynamics. This study suggests that electromagnetic benthic profiling in combination with machine learning techniques is a powerful tool to estimate grain-size distribution of marine sediments.

Predictive modelling of grain size distributions from marine electromagnetic profiling data using end-member analysis and a radial basis function network

NASA Astrophysics Data System (ADS)

Baasch, B.; M"uller, H.; von Dobeneck, T.

2018-04-01

In this work we present a new methodology to predict grain-size distributions from geophysical data. Specifically, electric conductivity and magnetic susceptibility of seafloor sediments recovered from electromagnetic profiling data are used to predict grain-size distributions along shelf-wide survey lines. Field data from the NW Iberian shelf are investigated and reveal a strong relation between the electromagnetic properties and grain-size distribution. The here presented workflow combines unsupervised and supervised machine learning techniques. Nonnegative matrix factorisation is used to determine grain-size end-members from sediment surface samples. Four end-members were found which well represent the variety of sediments in the study area. A radial-basis function network modified for prediction of compositional data is then used to estimate the abundances of these end-members from the electromagnetic properties. The end-members together with their predicted abundances are finally back transformed to grain-size distributions. A minimum spatial variation constraint is implemented in the training of the network to avoid overfitting and to respect the spatial distribution of sediment patterns. The predicted models are tested via leave-one-out cross-validation revealing high prediction accuracy with coefficients of determination (R2) between 0.76 and 0.89. The predicted grain-size distributions represent the well-known sediment facies and patterns on the NW Iberian shelf and provide new insights into their distribution, transition and dynamics. This study suggests that electromagnetic benthic profiling in combination with machine learning techniques is a powerful tool to estimate grain-size distribution of marine sediments.

Solar electricity supply isolines of generation capacity and storage.

PubMed

Grossmann, Wolf; Grossmann, Iris; Steininger, Karl W

2015-03-24

The recent sharp drop in the cost of photovoltaic (PV) electricity generation accompanied by globally rapidly increasing investment in PV plants calls for new planning and management tools for large-scale distributed solar networks. Of major importance are methods to overcome intermittency of solar electricity, i.e., to provide dispatchable electricity at minimal costs. We find that pairs of electricity generation capacity G and storage S that give dispatchable electricity and are minimal with respect to S for a given G exhibit a smooth relationship of mutual substitutability between G and S. These isolines between G and S support the solving of several tasks, including the optimal sizing of generation capacity and storage, optimal siting of solar parks, optimal connections of solar parks across time zones for minimizing intermittency, and management of storage in situations of far below average insolation to provide dispatchable electricity. G-S isolines allow determining the cost-optimal pair (G,S) as a function of the cost ratio of G and S. G-S isolines provide a method for evaluating the effect of geographic spread and time zone coverage on costs of solar electricity.

Solar electricity supply isolines of generation capacity and storage

PubMed Central

Grossmann, Wolf; Grossmann, Iris; Steininger, Karl W.

2015-01-01

The recent sharp drop in the cost of photovoltaic (PV) electricity generation accompanied by globally rapidly increasing investment in PV plants calls for new planning and management tools for large-scale distributed solar networks. Of major importance are methods to overcome intermittency of solar electricity, i.e., to provide dispatchable electricity at minimal costs. We find that pairs of electricity generation capacity G and storage S that give dispatchable electricity and are minimal with respect to S for a given G exhibit a smooth relationship of mutual substitutability between G and S. These isolines between G and S support the solving of several tasks, including the optimal sizing of generation capacity and storage, optimal siting of solar parks, optimal connections of solar parks across time zones for minimizing intermittency, and management of storage in situations of far below average insolation to provide dispatchable electricity. G−S isolines allow determining the cost-optimal pair (G,S) as a function of the cost ratio of G and S. G−S isolines provide a method for evaluating the effect of geographic spread and time zone coverage on costs of solar electricity. PMID:25755261

If it walks like a duck: nanosensor threat assessment

NASA Astrophysics Data System (ADS)

Chachis, George C.

2003-09-01

A convergence of technologies is making deployment of unattended ground nanosensors operationally feasible in terms of energy, communications for both arbitrated and self-organizing distributed, collective behaviors. A number of nano communications technologies are already making network-centric systems possible for MicroElectrical Mechanical (MEM) sensor devices today. Similar technologies may make NanoElectrical Mechanical (NEM) sensor devices operationally feasible a few years from now. Just as organizational behaviors of large numbers of nanodevices can derive strategies from social insects and other group-oriented animals, bio-inspired heuristics for threat assessment provide a conceptual approach for successful integration of nanosensors into unattended smart sensor networks. Biological models such as the organization of social insects or the dynamics of immune systems show promise as biologically-inspired paradigms for protecting nanosensor networks for security scene analysis and battlespace awareness. The paradox of nanosensors is that the smaller the device is the more useful it is but the smaller it is the more vulnerable it is to a variety of threats. In other words simpler means networked nanosensors are more likely to fall prey to a wide-range of attacks including jamming, spoofing, Janisserian recruitment, Pied-Piper distraction, as well as typical attacks computer network security. Thus, unattended sensor technologies call for network architectures that include security and countermeasures to provide reliable scene analysis or battlespace awareness information. Such network centric architectures may well draw upon a variety of bio-inspired approaches to safeguard, validate and make sense of large quantities of information.

Limitations of demand- and pressure-driven modeling for large deficient networks

NASA Astrophysics Data System (ADS)

Braun, Mathias; Piller, Olivier; Deuerlein, Jochen; Mortazavi, Iraj

2017-10-01

The calculation of hydraulic state variables for a network is an important task in managing the distribution of potable water. Over the years the mathematical modeling process has been improved by numerous researchers for utilization in new computer applications and the more realistic modeling of water distribution networks. But, in spite of these continuous advances, there are still a number of physical phenomena that may not be tackled correctly by current models. This paper will take a closer look at the two modeling paradigms given by demand- and pressure-driven modeling. The basic equations are introduced and parallels are drawn with the optimization formulations from electrical engineering. These formulations guarantee the existence and uniqueness of the solution. One of the central questions of the French and German research project ResiWater is the investigation of the network resilience in the case of extreme events or disasters. Under such extraordinary conditions where models are pushed beyond their limits, we talk about deficient network models. Examples of deficient networks are given by highly regulated flow, leakage or pipe bursts and cases where pressure falls below the vapor pressure of water. These examples will be presented and analyzed on the solvability and physical correctness of the solution with respect to demand- and pressure-driven models.

ABS-SmartComAgri: An Agent-Based Simulator of Smart Communication Protocols in Wireless Sensor Networks for Debugging in Precision Agriculture.

PubMed

García-Magariño, Iván; Lacuesta, Raquel; Lloret, Jaime

2018-03-27

Smart communication protocols are becoming a key mechanism for improving communication performance in networks such as wireless sensor networks. However, the literature lacks mechanisms for simulating smart communication protocols in precision agriculture for decreasing production costs. In this context, the current work presents an agent-based simulator of smart communication protocols for efficiently managing pesticides. The simulator considers the needs of electric power, crop health, percentage of alive bugs and pesticide consumption. The current approach is illustrated with three different communication protocols respectively called (a) broadcast, (b) neighbor and (c) low-cost neighbor. The low-cost neighbor protocol obtained a statistically-significant reduction in the need of electric power over the neighbor protocol, with a very large difference according to the common interpretations about the Cohen's d effect size. The presented simulator is called ABS-SmartComAgri and is freely distributed as open-source from a public research data repository. It ensures the reproducibility of experiments and allows other researchers to extend the current approach.

ABS-SmartComAgri: An Agent-Based Simulator of Smart Communication Protocols in Wireless Sensor Networks for Debugging in Precision Agriculture

PubMed Central

2018-01-01

Smart communication protocols are becoming a key mechanism for improving communication performance in networks such as wireless sensor networks. However, the literature lacks mechanisms for simulating smart communication protocols in precision agriculture for decreasing production costs. In this context, the current work presents an agent-based simulator of smart communication protocols for efficiently managing pesticides. The simulator considers the needs of electric power, crop health, percentage of alive bugs and pesticide consumption. The current approach is illustrated with three different communication protocols respectively called (a) broadcast, (b) neighbor and (c) low-cost neighbor. The low-cost neighbor protocol obtained a statistically-significant reduction in the need of electric power over the neighbor protocol, with a very large difference according to the common interpretations about the Cohen’s d effect size. The presented simulator is called ABS-SmartComAgri and is freely distributed as open-source from a public research data repository. It ensures the reproducibility of experiments and allows other researchers to extend the current approach. PMID:29584703

Long distance seawater intrusion through a karst conduit network in the Woodville Karst Plain, Florida

NASA Astrophysics Data System (ADS)

Xu, Zexuan; Bassett, Seth Willis; Hu, Bill; Dyer, Scott Barrett

2016-08-01

Five periods of increased electrical conductivity have been found in the karst conduits supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed conduit networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electrical conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and traveling 11 miles against the prevailing regional hydraulic gradient from from Spring Creek Spring Complex (SCSC), a group of submarine springs at the Gulf Coast. A geochemical analysis of samples from the spring vent rules out anthropogenic contamination and upwelling regional recharge from the deep aquifer as sources of the rising conductivity. The interpretation is supported by the conceptual model established by prior researchers working to characterize the study area. This paper documents the first and longest case of seawater intrusion in the WKP, and also indicates significant possibility of seawater contamination through subsurface conduit networks in a coastal karst aquifer.

Field observations of extended seawater intrusion through subsurface karst conduit networks at Wakulla Spring in the Woodville Karst Plain, Florida

NASA Astrophysics Data System (ADS)

Xu, Z.; Bassett, S.; Hu, B. X.; Dyer, S.

2016-12-01

Five periods of increased electrical conductivity have been found in the karst conduits supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed conduit networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electric conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and traveling 14 miles against the prevailing regional hydraulic gradient from from Spring Creek Spring Complex (SCSC), a group of submarine springs at the Gulf Coast. A geochemical analysis of samples from the spring vent rules out anthropogenic contamination and upwelling regional recharge from the deep aquifer as sources of the rising conductivity. The interpretation is supported by the conceptual model established by prior researchers working to characterize the study area. This abstract documented the first and longest case of seawater intrusion in the WKP, and also indicates significant possibility of seawater contamination through subsurface conduit networks in a coastal karst aquifer.

Long distance seawater intrusion through a karst conduit network in the Woodville Karst Plain, Florida.

PubMed

Xu, Zexuan; Bassett, Seth Willis; Hu, Bill; Dyer, Scott Barrett

2016-08-25

Five periods of increased electrical conductivity have been found in the karst conduits supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed conduit networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electrical conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and traveling 11 miles against the prevailing regional hydraulic gradient from from Spring Creek Spring Complex (SCSC), a group of submarine springs at the Gulf Coast. A geochemical analysis of samples from the spring vent rules out anthropogenic contamination and upwelling regional recharge from the deep aquifer as sources of the rising conductivity. The interpretation is supported by the conceptual model established by prior researchers working to characterize the study area. This paper documents the first and longest case of seawater intrusion in the WKP, and also indicates significant possibility of seawater contamination through subsurface conduit networks in a coastal karst aquifer.

Long distance seawater intrusion through a karst conduit network in the Woodville Karst Plain, Florida

PubMed Central

Xu, Zexuan; Bassett, Seth Willis; Hu, Bill; Dyer, Scott Barrett

2016-01-01

Five periods of increased electrical conductivity have been found in the karst conduits supplying one of the largest first magnitude springs in Florida with water. Numerous well-developed conduit networks are distributed in the Woodville Karst Plain (WKP), Florida and connected to the Gulf of Mexico. A composite analysis of precipitation and electrical conductivity data provides strong evidence that the increases in conductivity are directly tied to seawater intrusion moving inland and traveling 11 miles against the prevailing regional hydraulic gradient from from Spring Creek Spring Complex (SCSC), a group of submarine springs at the Gulf Coast. A geochemical analysis of samples from the spring vent rules out anthropogenic contamination and upwelling regional recharge from the deep aquifer as sources of the rising conductivity. The interpretation is supported by the conceptual model established by prior researchers working to characterize the study area. This paper documents the first and longest case of seawater intrusion in the WKP, and also indicates significant possibility of seawater contamination through subsurface conduit networks in a coastal karst aquifer. PMID:27557803

Cost analysis of an electricity supply chain using modification of price based dynamic economic dispatch in wheeling transaction scheme

NASA Astrophysics Data System (ADS)

Wahyuda; Santosa, Budi; Rusdiansyah, Ahmad

2018-04-01

Deregulation of the electricity market requires coordination between parties to synchronize the optimization on the production side (power station) and the transport side (transmission). Electricity supply chain presented in this article is designed to facilitate the coordination between the parties. Generally, the production side is optimized with price based dynamic economic dispatch (PBDED) model, while the transmission side is optimized with Multi-echelon distribution model. Both sides optimization are done separately. This article proposes a joint model of PBDED and multi-echelon distribution for the combined optimization of production and transmission. This combined optimization is important because changes in electricity demand on the customer side will cause changes to the production side that automatically also alter the transmission path. The transmission will cause two cost components. First, the cost of losses. Second, the cost of using the transmission network (wheeling transaction). Costs due to losses are calculated based on ohmic losses, while the cost of using transmission lines using the MW - mile method. As a result, this method is able to provide best allocation analysis for electrical transactions, as well as emission levels in power generation and cost analysis. As for the calculation of transmission costs, the Reverse MW-mile method produces a cheaper cost than the Absolute MW-mile method

A New Dual-Pore Formation Factor Model: A Percolation Network Study and Comparison to Experimental Data

NASA Astrophysics Data System (ADS)

Tang, Y. B.; Li, M.; Bernabe, Y.

2014-12-01

We modeled the electrical transport behavior of dual-pore carbonate rocks in this paper. Based on experimental data of a carbonate reservoir in China, we simply considered the low porosity samples equivalent to the matrix (micro-pore system) of the high porosity samples. For modeling the bimodal porous media, we considered that the matrix is homogeneous and interconnected. The connectivity and the pore size distribution of macro-pore system are varied randomly. Both pore systems are supposed to act electrically in parallel, connected at the nodes, where the fluid exchange takes place, an approach previously used by Bauer et al. (2012). Then, the effect of the properties of matrix, the pore size distribution and connectivity of macro-pore system on petrophysical properties of carbonates can be investigated. We simulated electrical current through networks in three-dimensional simple cubic (SC) and body-center cubic (BCC) with different coordination numbers and different pipe radius distributions of macro-pore system. Based on the simulation results, we found that the formation factor obeys a "universal" scaling relationship (i.e. independent of lattice type), 1/F∝eγz, where γ is a function of the normalized standard deviation of the pore radius distribution of macro-pore system and z is the coordination number of macro-pore system. This relationship is different from the classic "universal power law" in percolation theory. A formation factor model was inferred on the basis of the scaling relationship mentioned above and several scale-invariant quantities (such as hydraulic radius rH and throat length l of macro-pore). Several methods were developed to estimate corresponding parameters of the new model with conventional core analyses. It was satisfactorily tested against experimental data, including some published experimental data. Furthermore, the relationship between water saturation and resistivity in dual-pore carbonates was discussed based on the new model.

Accelerating the Integration of Distributed Water Solutions: A Conceptual Financing Model from the Electricity Sector

NASA Astrophysics Data System (ADS)

Quesnel, Kimberly J.; Ajami, Newsha K.; Wyss, Noemi

2017-11-01

Modern challenges require new approaches to urban water management. One solution in the portfolio of potential strategies is the integration of distributed water infrastructure, practices, and technologies into existing systems. However, many practical barriers have prevented the widespread adoption of these systems in the US. The objective of this paper is to address these challenges by developing a conceptual model encompassing regulatory, financial, and governance components that can be used to incorporate new distributed water solutions into our current network. To construct the model, case studies of successfully implemented distributed electricity systems, specifically energy efficiency and renewable energy technologies, were examined to determine how these solutions have become prominent in recent years and what lessons can be applied to the water sector in a similar pursuit. The proposed model includes four action-oriented elements: catalyzing change, establishing funding sources, using resource pathways, and creating innovative governance structures. As illustrated in the model, the water sector should use suite of coordinated policies to promote change, engage end users through fiscal incentives, and encourage research, development and dissemination of new technologies over time.

Accelerating the Integration of Distributed Water Solutions: A Conceptual Financing Model from the Electricity Sector.

PubMed

Quesnel, Kimberly J; Ajami, Newsha K; Wyss, Noemi

2017-11-01

Modern challenges require new approaches to urban water management. One solution in the portfolio of potential strategies is the integration of distributed water infrastructure, practices, and technologies into existing systems. However, many practical barriers have prevented the widespread adoption of these systems in the US. The objective of this paper is to address these challenges by developing a conceptual model encompassing regulatory, financial, and governance components that can be used to incorporate new distributed water solutions into our current network. To construct the model, case studies of successfully implemented distributed electricity systems, specifically energy efficiency and renewable energy technologies, were examined to determine how these solutions have become prominent in recent years and what lessons can be applied to the water sector in a similar pursuit. The proposed model includes four action-oriented elements: catalyzing change, establishing funding sources, using resource pathways, and creating innovative governance structures. As illustrated in the model, the water sector should use suite of coordinated policies to promote change, engage end users through fiscal incentives, and encourage research, development and dissemination of new technologies over time.

Optimal Output of Distributed Generation Based On Complex Power Increment

NASA Astrophysics Data System (ADS)

Wu, D.; Bao, H.

2017-12-01

In order to meet the growing demand for electricity and improve the cleanliness of power generation, new energy generation, represented by wind power generation, photovoltaic power generation, etc has been widely used. The new energy power generation access to distribution network in the form of distributed generation, consumed by local load. However, with the increase of the scale of distribution generation access to the network, the optimization of its power output is becoming more and more prominent, which needs further study. Classical optimization methods often use extended sensitivity method to obtain the relationship between different power generators, but ignore the coupling parameter between nodes makes the results are not accurate; heuristic algorithm also has defects such as slow calculation speed, uncertain outcomes. This article proposes a method called complex power increment, the essence of this method is the analysis of the power grid under steady power flow. After analyzing the results we can obtain the complex scaling function equation between the power supplies, the coefficient of the equation is based on the impedance parameter of the network, so the description of the relation of variables to the coefficients is more precise Thus, the method can accurately describe the power increment relationship, and can obtain the power optimization scheme more accurately and quickly than the extended sensitivity method and heuristic method.

Electro-textile garments for power and data distribution

NASA Astrophysics Data System (ADS)

Slade, Jeremiah R.; Winterhalter, Carole

2015-05-01

U.S. troops are increasingly being equipped with various electronic assets including flexible displays, computers, and communications systems. While these systems can significantly enhance operational capabilities, forming reliable connections between them poses a number of challenges in terms of comfort, weight, ergonomics, and operational security. IST has addressed these challenges by developing the technologies needed to integrate large-scale cross-seam electrical functionality into virtually any textile product, including the various garments and vests that comprise the warfighter's ensemble. Using this technology IST is able to develop textile products that do not simply support or accommodate a network but are the network.

Change in Brooklyn and Queens: How New York?s Reforming the Energy Vision Program and Con Edison Are Reshaping Electric Distribution Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coddington, Michael; Sciano, Damian; Fuller, Jason

In response to this tremendous growth in both population and electricity demand, Con Edison estimates that its cost to expand the “traditional” Brooklyn-Queens grid will be in the neighborhood of US$1.2 billion—a relatively high number, even for New York City and Con Edison. The complexity of the city’s underground electrical system along with the difficulties of construction in a highly congested urban environment with infrastructure both above and below ground mean that the costs for transmission, substations, and secondary networks are significantly higher than those of a typical electric utility. The New York State Public Service Commission (PSC) is inmore » the process revising its approach to acquiring and serving energy throughout the state of New York, and traditional expansion for this rather costly project was not likely to be approved. Instead, the PSC asked Con Edison to evaluate numerous alternatives. The PSC and Con Edison are now considering and adopting strategies that include renewable energy generation, demand response (DR), battery energy storage systems, fuel-cell distributed generation, combined heat and power, volt-volt ampere reactive (VAR) optimization (VVO), and a host of other innovative solutions that would both reduce electricity demand and transform how and when Con Edison’s consumers use electricity.« less

Monte Carlo simulations of electrical percolation in multicomponent thin films with nanofillers

NASA Astrophysics Data System (ADS)

Ni, Xiaojuan; Hui, Chao; Su, Ninghai; Jiang, Wei; Liu, Feng

2018-02-01

We developed a 2D disk-stick percolation model to investigate the electrical percolation behavior of an insulating thin film reinforced with 1D and 2D conductive nanofillers via Monte Carlo simulation. Numerical predictions of the percolation threshold in single component thin films showed good agreement with the previous published work, validating our model for investigating the characteristics of the percolation phenomena. Parametric studies of size effect, i.e., length of 1D nanofiller and diameter of 2D nanofiller, were carried out to predict the electrical percolation threshold for hybrid systems. The relationships between the nanofillers in two hybrid systems was established, which showed differences from previous linear assumption. The effective electrical conductance was evaluated through Kirchhoff’s current law by transforming it into a resistor network. The equivalent resistance was obtained from the distribution of nodal voltages by solving a system of linear equations with a Gaussian elimination method. We examined the effects of stick length, relative concentration, and contact patterns of 1D/2D inclusions on electrical performance. One novel aspect of our study is its ability to investigate the effective conductance of nanocomposites as a function of relative concentrations, which shows there is a synergistic effect when nanofillers with different dimensionalities combine properly. Our work provides an important theoretical basis for designing the conductive networks and predicting the percolation properties of multicomponent nanocomposites.

Thermally Stimulated Currents in Nanocrystalline Titania

PubMed Central

Bruzzi, Mara; Mori, Riccardo; Baldi, Andrea; Cavallaro, Alessandro; Scaringella, Monica

2018-01-01

A thorough study on the distribution of defect-related active energy levels has been performed on nanocrystalline TiO2. Films have been deposited on thick-alumina printed circuit boards equipped with electrical contacts, heater and temperature sensors, to carry out a detailed thermally stimulated currents analysis on a wide temperature range (5–630 K), in view to evidence contributions from shallow to deep energy levels within the gap. Data have been processed by numerically modelling electrical transport. The model considers both free and hopping contribution to conduction, a density of states characterized by an exponential tail of localized states below the conduction band and the convolution of standard Thermally Stimulated Currents (TSC) emissions with gaussian distributions to take into account the variability in energy due to local perturbations in the highly disordered network. Results show that in the low temperature range, up to 200 K, hopping within the exponential band tail represents the main contribution to electrical conduction. Above room temperature, electrical conduction is dominated by free carriers contribution and by emissions from deep energy levels, with a defect density ranging within 1014–1018 cm−3, associated with physio- and chemi-sorbed water vapour, OH groups and to oxygen vacancies. PMID:29303976

Thermally Stimulated Currents in Nanocrystalline Titania.

PubMed

Bruzzi, Mara; Mori, Riccardo; Baldi, Andrea; Carnevale, Ennio Antonio; Cavallaro, Alessandro; Scaringella, Monica

2018-01-05

A thorough study on the distribution of defect-related active energy levels has been performed on nanocrystalline TiO₂. Films have been deposited on thick-alumina printed circuit boards equipped with electrical contacts, heater and temperature sensors, to carry out a detailed thermally stimulated currents analysis on a wide temperature range (5-630 K), in view to evidence contributions from shallow to deep energy levels within the gap. Data have been processed by numerically modelling electrical transport. The model considers both free and hopping contribution to conduction, a density of states characterized by an exponential tail of localized states below the conduction band and the convolution of standard Thermally Stimulated Currents (TSC) emissions with gaussian distributions to take into account the variability in energy due to local perturbations in the highly disordered network. Results show that in the low temperature range, up to 200 K, hopping within the exponential band tail represents the main contribution to electrical conduction. Above room temperature, electrical conduction is dominated by free carriers contribution and by emissions from deep energy levels, with a defect density ranging within 10 14 -10 18 cm -3 , associated with physio- and chemi-sorbed water vapour, OH groups and to oxygen vacancies.

VIDAC; A New Technology for Increasing the Effectiveness of Television Distribution Networks: Report on a Feasibility Study of a Central Library "Integrated Media" Satellite Delivery System.

ERIC Educational Resources Information Center

Diambra, Henry M.; And Others

VIDAC (Video Audio Compressed), a new technology based upon non-real-time transmission of audiovisual information via conventional television systems, has been invented by the Westinghouse Electric Corporation. This system permits time compression, during storage and transmission of the audio component of a still visual-narrative audio…

Microfluidic System Simulation Including the Electro-Viscous Effect

NASA Technical Reports Server (NTRS)

Rojas, Eileen; Chen, C. P.; Majumdar, Alok

2007-01-01

This paper describes a practical approach using a general purpose lumped-parameter computer program, GFSSP (Generalized Fluid System Simulation Program) for calculating flow distribution in a network of micro-channels including electro-viscous effects due to the existence of electrical double layer (EDL). In this study, an empirical formulation for calculating an effective viscosity of ionic solutions based on dimensional analysis is described to account for surface charge and bulk fluid conductivity, which give rise to electro-viscous effect in microfluidics network. Two dimensional slit micro flow data was used to determine the model coefficients. Geometry effect is then included through a Poiseuille number correlation in GFSSP. The bi-power model was used to calculate flow distribution of isotropically etched straight channel and T-junction microflows involving ionic solutions. Performance of the proposed model is assessed against experimental test data.

The effect of body bias of the metal-oxide-semiconductor field-effect transistor in the resistive network on spatial current distribution in a bio-inspired complementary metal-oxide-semiconductor vision chip

NASA Astrophysics Data System (ADS)

Kong, Jae-Sung; Hyun, Hyo-Young; Seo, Sang-Ho; Shin, Jang-Kyoo

2008-11-01

Complementary metal-oxide-semiconductor (CMOS) vision chips for edge detection based on a resistive circuit have recently been developed. These chips help in the creation of neuromorphic systems of a compact size, high speed of operation, and low power dissipation. The output of the vision chip depends predominantly upon the electrical characteristics of the resistive network which consists of a resistive circuit. In this paper, the body effect of the metal-oxide-semiconductor field-effect transistor for current distribution in a resistive circuit is discussed with a simple model. In order to evaluate the model, two 160 × 120 CMOS vision chips have been fabricated using a standard CMOS technology. The experimental results nicely match our prediction.

A study on reliability of power customer in distribution network

NASA Astrophysics Data System (ADS)

Liu, Liyuan; Ouyang, Sen; Chen, Danling; Ma, Shaohua; Wang, Xin

2017-05-01

The existing power supply reliability index system is oriented to power system without considering actual electricity availability in customer side. In addition, it is unable to reflect outage or customer’s equipment shutdown caused by instantaneous interruption and power quality problem. This paper thus makes a systematic study on reliability of power customer. By comparing with power supply reliability, reliability of power customer is defined and extracted its evaluation requirements. An indexes system, consisting of seven customer indexes and two contrast indexes, are designed to describe reliability of power customer from continuity and availability. In order to comprehensively and quantitatively evaluate reliability of power customer in distribution networks, reliability evaluation method is proposed based on improved entropy method and the punishment weighting principle. Practical application has proved that reliability index system and evaluation method for power customer is reasonable and effective.

Sliceable transponders for metro-access transmission links

NASA Astrophysics Data System (ADS)

Wagner, C.; Madsen, P.; Spolitis, S.; Vegas Olmos, J. J.; Tafur Monroy, I.

2015-01-01

This paper presents a solution for upgrading optical access networks by reusing existing electronics or optical equipment: sliceable transponders using signal spectrum slicing and stitching back method after direct detection. This technique allows transmission of wide bandwidth signals from the service provider (OLT - optical line terminal) to the end user (ONU - optical network unit) over an optical distribution network (ODN) via low bandwidth equipment. We show simulation and experimental results for duobinary signaling of 1 Gbit/s and 10 Gbit/s waveforms. The number of slices is adjusted to match the lowest analog bandwidth of used electrical devices and scale from 2 slices to 10 slices. Results of experimental transmission show error free signal recovery by using post forward error correction with 7% overhead.

Optimization based on benefit of regional energy suppliers of distributed generation in active distribution network

NASA Astrophysics Data System (ADS)

Huo, Xianxu; Li, Guodong; Jiang, Ling; Wang, Xudong

2017-08-01

With the development of electricity market, distributed generation (DG) technology and related policies, regional energy suppliers are encouraged to build DG. Under this background, the concept of active distribution network (ADN) is put forward. In this paper, a bi-level model of intermittent DG considering benefit of regional energy suppliers is proposed. The objective of the upper level is the maximization of benefit of regional energy suppliers. On this basis, the lower level is optimized for each scene. The uncertainties of DG output and load of users, as well as four active management measures, which include demand-side management, curtailing the output power of DG, regulating reactive power compensation capacity and regulating the on-load tap changer, are considered. Harmony search algorithm and particle swarm optimization are combined as a hybrid strategy to solve the model. This model and strategy are tested with IEEE-33 node system, and results of case study indicate that the model and strategy successfully increase the capacity of DG and benefit of regional energy suppliers.

Enhancement of Electrical Conductivity in Multicomponent Nanocomposites.

NASA Astrophysics Data System (ADS)

Ni, Xiaojuan; Hui, Chao; Su, Ninghai; Liu, Feng

To date, very limited theoretical or numerical analyses have been carried out to understand the electrical percolation properties in multicomponent nanocomposite systems. In this work, a disk-stick percolation model was developed to investigate the electrical percolation behavior of an electrically insulating matrix reinforced with one-dimensional (1D) and two-dimensional (2D) conductors via Monte Carlo simulation. The effective electrical conductivity was evaluated through Kirchhoff's current law by transforming it into an equivalent resistor network. The percolation threshold, equivalent resistance and conductivity were obtained from the distribution of nodal voltages by solving a system of linear equations with Gaussian elimination method. The effects of size, aspect ratio, relative concentration and contact patterns of 1D/2D inclusions on conductivity performance were examined. Our model is able to predict the electrical percolation threshold and evaluate the conductivity for hybrid systems with multiple components. The results suggest that carbon-based nanocomposites can have a high potential for applications where favorable electrical properties and low specific weight are required. We acknowledge the financial support from DOE-BES (No. DE-FG02-04ER46148).

Decentralized energy systems for clean electricity access

NASA Astrophysics Data System (ADS)

Alstone, Peter; Gershenson, Dimitry; Kammen, Daniel M.

2015-04-01

Innovative approaches are needed to address the needs of the 1.3 billion people lacking electricity, while simultaneously transitioning to a decarbonized energy system. With particular focus on the energy needs of the underserved, we present an analytic and conceptual framework that clarifies the heterogeneous continuum of centralized on-grid electricity, autonomous mini- or community grids, and distributed, individual energy services. A historical analysis shows that the present day is a unique moment in the history of electrification where decentralized energy networks are rapidly spreading, based on super-efficient end-use appliances and low-cost photovoltaics. We document how this evolution is supported by critical and widely available information technologies, particularly mobile phones and virtual financial services. These disruptive technology systems can rapidly increase access to basic electricity services and directly inform the emerging Sustainable Development Goals for quality of life, while simultaneously driving action towards low-carbon, Earth-sustaining, inclusive energy systems.

Modeling Percolation in Polymer Nanocomposites by Stochastic Microstructuring

PubMed Central

Soto, Matias; Esteva, Milton; Martínez-Romero, Oscar; Baez, Jesús; Elías-Zúñiga, Alex

2015-01-01

A methodology was developed for the prediction of the electrical properties of carbon nanotube-polymer nanocomposites via Monte Carlo computational simulations. A two-dimensional microstructure that takes into account waviness, fiber length and diameter distributions is used as a representative volume element. Fiber interactions in the microstructure are identified and then modeled as an equivalent electrical circuit, assuming one-third metallic and two-thirds semiconductor nanotubes. Tunneling paths in the microstructure are also modeled as electrical resistors, and crossing fibers are accounted for by assuming a contact resistance associated with them. The equivalent resistor network is then converted into a set of linear equations using nodal voltage analysis, which is then solved by means of the Gauss–Jordan elimination method. Nodal voltages are obtained for the microstructure, from which the percolation probability, equivalent resistance and conductivity are calculated. Percolation probability curves and electrical conductivity values are compared to those found in the literature. PMID:28793594

Power harvesting for railroad track safety enhancement using vertical track displacement

NASA Astrophysics Data System (ADS)

Nelson, Carl A.; Platt, Stephen R.; Hansen, Sean E.; Fateh, Mahmood

2009-03-01

A significant portion of railroad infrastructure exists in areas that are relatively remote. Railroad crossings in these areas are typically only marked with reflective signage and do not have warning light systems or crossbars due to the cost of electrical infrastructure. Distributed sensor networks used for railroad track health monitoring applications would be useful in these areas, but the same limitation regarding electrical infrastructure exists. This motivates the search for a long-term, low-maintenance power supply solution for remote railroad deployment. This paper describes the development of a mechanical device for harvesting mechanical power from passing railcar traffic that can be used to supply electrical power to warning light systems at crossings and to remote networks of sensors via rechargeable batteries. The device is mounted to and spans two rail ties such that it directly harnesses the vertical displacement of the rail and attached ties and translates the linear motion into rotational motion. The rotational motion is amplified and mechanically rectified to rotate a PMDC generator that charges a system of batteries. A prototype was built and tested in a laboratory setting for verifying functionality of the design. Results indicate power production capabilities on the order of 10 W per device in its current form. This is sufficient for illuminating high-efficiency LED lights at a railroad crossing or for powering track-health sensor networks.

Architecture and Methods for Substation SCADA Cybersecurity: Best Practices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Albunashee, Hamdi; Al Sarray, Muthanna; McCann, Roy

There are over 3000 electricity providers in the United States, encompassing investor and publicly owned utilities as well as electric cooperatives. There has been ongoing trends to increasingly automate and provide remote control and monitoring of electric energy delivery systems. The deployment of computer network technologies has increased the efficiency and reliability of electric power infrastructure. However, the increased use of digital communications has also increased the vulnerability to malicious cyber attacks [1]. In 2004 the National Research Councils (National Academies) formed a committee of specialists to address these vulnerabilities and propose possible solutions with an objective to prioritize themore » R&D needs for developing countermeasures. The committee addressed many potential concerns in the electric power delivery system and classified them based upon different criteria and presented recommendations to minimize the gap between the academic research directions and the needs of the electric utility industry. The complexity and diversity of the electric power delivery system in the U.S. has opened many ports for attackers and intruders [1]. This complexity and diversity is attributed to the fact that power delivery system is a network of substations, transmission and distribution lines, sub-networks of controlling, sensing and monitoring units, and human operator involvement for running the system [1]. Accordingly, any incident such as the occurrence of a fault or disturbance in this complex network cannot be deferred and should be resolved within an order of milliseconds, otherwise there is risk of large-scale outages similar to the occurrences in India and the U.S. in 2003 [2]. There are three main vulnerabilities in supervisory control and data acquisition (SCADA) systems commonly identified—physical vulnerability, cyber vulnerability and personal vulnerability [1]. In terms of cyber threats, SCADA systems are the most critical elements in the electric power grid in the U.S. Unauthorized access to a SCADA system could enable/disable unexpected equipment (such as disable the protection system or a circuit breaker) which could cause large scale disruptions of electric power delivery. This paper provides an overview of power system SCADA technologies in transmission substations (Section 2) and summarizes the best practices for implementing a cyber security program. After introducing SCADA system operations in Section 2, a description of the security challenges for SCADA systems is presented in Section 3. In Section 4, NECRC Critical Infrastructure Protection standards CIP-002 through CIP-009 are summarized. An overview of industry best practices is presented in Section 5.« less

Worldwide electricity used in data centers

NASA Astrophysics Data System (ADS)

Koomey, Jonathan G.

2008-07-01

The direct electricity used by data centers has become an important issue in recent years as demands for new Internet services (such as search, music downloads, video-on-demand, social networking, and telephony) have become more widespread. This study estimates historical electricity used by data centers worldwide and regionally on the basis of more detailed data than were available for previous assessments, including electricity used by servers, data center communications, and storage equipment. Aggregate electricity use for data centers doubled worldwide from 2000 to 2005. Three quarters of this growth was the result of growth in the number of the least expensive (volume) servers. Data center communications and storage equipment each contributed about 10% of the growth. Total electricity use grew at an average annual rate of 16.7% per year, with the Asia Pacific region (without Japan) being the only major world region with growth significantly exceeding that average. Direct electricity used by information technology equipment in data centers represented about 0.5% of total world electricity consumption in 2005. When electricity for cooling and power distribution is included, that figure is about 1%. Worldwide data center power demand in 2005 was equivalent (in capacity terms) to about seventeen 1000 MW power plants.

Electric field generated by longitudinal axial microtubule vibration modes with high spatial resolution microtubule model

NASA Astrophysics Data System (ADS)

Cifra, M.; Havelka, D.; Deriu, M. A.

2011-12-01

Microtubules are electrically polar structures fulfilling prerequisites for generation of oscillatory electric field in the kHz to GHz region. Energy supply for excitation of elasto-electrical vibrations in microtubules may be provided from GTP-hydrolysis; motor protein-microtubule interactions; and energy efflux from mitochondria. It recently was determined from anisotropic elastic network modeling of entire microtubules that the frequencies of microtubule longitudinal axial eigenmodes lie in the region of tens of GHz for the physiologically common microtubule lengths. We calculated electric field generated by axial longitudinal vibration modes of microtubule, which model is based on subnanometer precision of charge distribution. Due to elastoelectric nature of the vibrations, the vibration wavelength is million-fold shorter than that of the electromagnetic field in free space and the electric field around the microtubule manifests rich spatial structure with multiple minima. The dielectrophoretic force exerted by electric field on the surrounding molecules will influence the kinetics of reactions via change in the probability of the transport of charge and mass particles. The electric field generated by vibrations of electrically polar cellular structures is expected to play a role in biological self-organization.

Integration of SPS with utility system networks

NASA Technical Reports Server (NTRS)

Kaupang, B. M.

1980-01-01

The integration of Satellite Power System (SPS) power in electric utility power systems is discussed. Specifically, the nature of the power output variations from the spacecraft to the rectenna, the operational characteristics of the rectenna power, and the impacts on the electric utility system from utilizing SPS power to serve part of the system load are treated. It is concluded that if RF beam control is an acceptable method for power control, and that the site distribution of SPS rectennas do not cause a very high local penetration (40 to 50%), SPS may be integrated into electric utility system with a few negative impacts. Increased regulating duty on the conventional generation, and a potential impact on system reliability for SPS penetration in excess of about 25% appear to be two areas of concern.

Integral electrical characteristics and local plasma parameters of a RF ion thruster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masherov, P. E.; Riaby, V. A., E-mail: riaby2001@yahoo.com; Godyak, V. A.

2016-02-15

Comprehensive diagnostics has been carried out for a RF ion thruster based on inductively coupled plasma (ICP) source with an external flat antenna coil enhanced by ferrite core. The ICP was confined within a cylindrical chamber with low aspect ratio to minimize plasma loss to the chamber wall. Integral diagnostics of the ICP electrical parameters (RF power balance and coil current) allowed for evaluation of the antenna coils, matching networks, and eddy current loss and the true RF power deposited to plasma. Spatially resolved electron energy distribution functions, plasma density, electron temperatures, and plasma potentials were measured with movable Langmuirmore » probes.« less

Heating the sun's lower transition region with fine-scale electric currents

NASA Technical Reports Server (NTRS)

Rabin, D.; Moore, R.

1984-01-01

Analytical and observational data are presented to show that the lower transition zone, a 100 km thick region at 10,000-200,000 K between the solar chromosphere and corona, is heated by local electric currents. The study was spurred by correlations between the enhanced atmospheric heating and magnetospheric flux in the chromospheric network and active regions. Field aligned current heated flux loops are asserted to mainly reside in and make up most of the transition region. It is shown that thermal conduction from the sides of hot gas columns generated by the current dissipation is the source of the observed temperature distribution in the transition regions.

Analysis of the energy efficiency of the implementation power electric generated modules in the CHS

NASA Astrophysics Data System (ADS)

Sukhikh, A. A.; Milyutin, V. A.; Lvova, A. M.

2017-11-01

Application on the Central heat source (CHS) local generation of electricity is primarily aimed at solving problems of own needs of electric energy that not only guarantees the independence of the work of the CHS from external electrical networks, but will prevent the stop of heat supply of consumers and defrosting heating networks in case of accidents in electrical networks caused by natural or anthropogenic factors. Open the prospects of electric power supply stand-alone objects, such commercial or industrial objects on the territory of a particular neighborhood.

ROLE OF THE NETWORK FORMER IN SEMICONDUCTING OXIDE GLASSES.

DTIC Science & Technology

SEMICONDUCTOR DEVICES, * GLASS ), (*ELECTRICAL NETWORKS, GLASS ), ELECTRICAL PROPERTIES, SEEBECK EFFECT, BORATES, PHOSPHATES, ELECTRICAL RESISTANCE, X RAY DIFFRACTION, ANNEALING, OXIDATION, OXIDES, ELECTRODES, VANADIUM

Effects of Electrical and Optogenetic Deep Brain Stimulation on Synchronized Oscillatory Activity in Parkinsonian Basal Ganglia.

PubMed

Ratnadurai-Giridharan, Shivakeshavan; Cheung, Chung C; Rubchinsky, Leonid L

2017-11-01

Conventional deep brain stimulation of basal ganglia uses high-frequency regular electrical pulses to treat Parkinsonian motor symptoms but has a series of limitations. Relatively new and not yet clinically tested, optogenetic stimulation is an effective experimental stimulation technique to affect pathological network dynamics. We compared the effects of electrical and optogenetic stimulation of the basal gangliaon the pathologicalParkinsonian rhythmic neural activity. We studied the network response to electrical stimulation and excitatory and inhibitory optogenetic stimulations. Different stimulations exhibit different interactions with pathological activity in the network. We studied these interactions for different network and stimulation parameter values. Optogenetic stimulation was found to be more efficient than electrical stimulation in suppressing pathological rhythmicity. Our findings indicate that optogenetic control of neural synchrony may be more efficacious than electrical control because of the different ways of how stimulations interact with network dynamics.

Price Based Local Power Distribution Management System (Local Power Distribution Manager) v1.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

BROWN, RICHARD E.; CZARNECKI, STEPHEN; SPEARS, MICHAEL

2016-11-28

A trans-active energy micro-grid controller is implemented in the VOLTTRON distributed control platform. The system uses the price of electricity as the mechanism for conducting transactions that are used to manage energy use and to balance supply and demand. In order to allow testing and analysis of the control system, the implementation is designed to run completely as a software simulation, while allowing the inclusion of selected hardware that physically manages power. Equipment to be integrated with the micro-grid controller must have an IP (Internet Protocol)-based network connection and a software "driver" must exist to translate data communications between themore » device and the controller.« less

Reliability Modeling of Microelectromechanical Systems Using Neural Networks

NASA Technical Reports Server (NTRS)

Perera. J. Sebastian

2000-01-01

Microelectromechanical systems (MEMS) are a broad and rapidly expanding field that is currently receiving a great deal of attention because of the potential to significantly improve the ability to sense, analyze, and control a variety of processes, such as heating and ventilation systems, automobiles, medicine, aeronautical flight, military surveillance, weather forecasting, and space exploration. MEMS are very small and are a blend of electrical and mechanical components, with electrical and mechanical systems on one chip. This research establishes reliability estimation and prediction for MEMS devices at the conceptual design phase using neural networks. At the conceptual design phase, before devices are built and tested, traditional methods of quantifying reliability are inadequate because the device is not in existence and cannot be tested to establish the reliability distributions. A novel approach using neural networks is created to predict the overall reliability of a MEMS device based on its components and each component's attributes. The methodology begins with collecting attribute data (fabrication process, physical specifications, operating environment, property characteristics, packaging, etc.) and reliability data for many types of microengines. The data are partitioned into training data (the majority) and validation data (the remainder). A neural network is applied to the training data (both attribute and reliability); the attributes become the system inputs and reliability data (cycles to failure), the system output. After the neural network is trained with sufficient data. the validation data are used to verify the neural networks provided accurate reliability estimates. Now, the reliability of a new proposed MEMS device can be estimated by using the appropriate trained neural networks developed in this work.

Acoustic Network Localization and Interpretation of Infrasonic Pulses from Lightning

NASA Astrophysics Data System (ADS)

Arechiga, R. O.; Johnson, J. B.; Badillo, E.; Michnovicz, J. C.; Thomas, R. J.; Edens, H. E.; Rison, W.

2011-12-01

We improve on the localization accuracy of thunder sources and identify infrasonic pulses that are correlated across a network of acoustic arrays. We attribute these pulses to electrostatic charge relaxation (collapse of the electric field) and attempt to model their spatial extent and acoustic source strength. Toward this objective we have developed a single audio range (20-15,000 Hz) acoustic array and a 4-station network of broadband (0.01-500 Hz) microphone arrays with aperture of ~45 m. The network has an aperture of 1700 m and was installed during the summers of 2009-2011 in the Magdalena mountains of New Mexico, an area that is subject to frequent lightning activity. We are exploring a new technique based on inverse theory that integrates information from the audio range and the network of broadband acoustic arrays to locate thunder sources more accurately than can be achieved with a single array. We evaluate the performance of the technique by comparing the location of thunder sources with RF sources located by the lightning mapping array (LMA) of Langmuir Laboratory at New Mexico Tech. We will show results of this technique for lightning flashes that occurred in the vicinity of our network of acoustic arrays and over the LMA. We will use acoustic network detection of infrasonic pulses together with LMA data and electric field measurements to estimate the spatial distribution of the charge (within the cloud) that is used to produce a lightning flash, and will try to quantify volumetric charges (charge magnitude) within clouds.

Multicellular automaticity of cardiac cell monolayers: effects of density and spatial distribution of pacemaker cells

NASA Astrophysics Data System (ADS)

Elber Duverger, James; Boudreau-Béland, Jonathan; Le, Minh Duc; Comtois, Philippe

2014-11-01

Self-organization of pacemaker (PM) activity of interconnected elements is important to the general theory of reaction-diffusion systems as well as for applications such as PM activity in cardiac tissue to initiate beating of the heart. Monolayer cultures of neonatal rat ventricular myocytes (NRVMs) are often used as experimental models in studies on cardiac electrophysiology. These monolayers exhibit automaticity (spontaneous activation) of their electrical activity. At low plated density, cells usually show a heterogeneous population consisting of PM and quiescent excitable cells (QECs). It is therefore highly probable that monolayers of NRVMs consist of a heterogeneous network of the two cell types. However, the effects of density and spatial distribution of the PM cells on spontaneous activity of monolayers remain unknown. Thus, a simple stochastic pattern formation algorithm was implemented to distribute PM and QECs in a binary-like 2D network. A FitzHugh-Nagumo excitable medium was used to simulate electrical spontaneous and propagating activity. Simulations showed a clear nonlinear dependency of spontaneous activity (occurrence and amplitude of spontaneous period) on the spatial patterns of PM cells. In most simulations, the first initiation sites were found to be located near the substrate boundaries. Comparison with experimental data obtained from cardiomyocyte monolayers shows important similarities in the position of initiation site activity. However, limitations in the model that do not reflect the complex beat-to-beat variation found in experiments indicate the need for a more realistic cardiomyocyte representation.

Computer-Assisted Monitoring Of A Complex System

NASA Technical Reports Server (NTRS)

Beil, Bob J.; Mickelson, Eric M.; Sterritt, John M.; Costantino, Rob W.; Houvener, Bob C.; Super, Mike A.

1995-01-01

Propulsion System Advisor (PSA) computer-based system assists engineers and technicians in analyzing masses of sensory data indicative of operating conditions of space shuttle propulsion system during pre-launch and launch activities. Designed solely for monitoring; does not perform any control functions. Although PSA developed for highly specialized application, serves as prototype of noncontrolling, computer-based subsystems for monitoring other complex systems like electric-power-distribution networks and factories.

Shuttle Electrical Power Analysis Program (SEPAP); single string circuit analysis report

NASA Technical Reports Server (NTRS)

Murdock, C. R.

1974-01-01

An evaluation is reported of the data obtained from an analysis of the distribution network characteristics of the shuttle during a spacelab mission. A description of the approach utilized in the development of the computer program and data base is provided and conclusions are drawn from the analysis of the data. Data sheets are provided for information to support the detailed discussion on each computer run.

Multimodal EEG Recordings, Psychometrics and Behavioural Analysis.

PubMed

Boeijinga, Peter H

2015-01-01

High spatial and temporal resolution measurements of neuronal activity are preferably combined. In an overview on how this approach can take shape, multimodal electroencephalography (EEG) is treated in 2 main parts: by experiments without a task and in the experimentally cued working brain. It concentrates first on the alpha rhythm properties and next on data-driven search for patterns such as the default mode network. The high-resolution volumic distributions of neuronal metabolic indices result in distributed cortical regions and possibly relate to numerous nuclei, observable in a non-invasive manner in the central nervous system of humans. The second part deals with paradigms in which nowadays assessment of target-related networks can align level-dependent blood oxygenation, electrical responses and behaviour, taking the temporal resolution advantages of event-related potentials. Evidence-based electrical propagation in serial tasks during performance is now to a large extent attributed to interconnected pathways, particularly chronometry-dependent ones, throughout a chain including a dorsal stream, next ventral cortical areas taking the flow of information towards inferior temporal domains. The influence of aging is documented, and results of the first multimodal studies in neuropharmacology are consistent. Finally a scope on implementation of advanced clinical applications and personalized marker strategies in neuropsychiatry is indicated. © 2016 S. Karger AG, Basel.

Resolution-Enhanced Harmonic and Interharmonic Measurement for Power Quality Analysis in Cyber-Physical Energy System.

PubMed

Liu, Yanchi; Wang, Xue; Liu, Youda; Cui, Sujin

2016-06-27

Power quality analysis issues, especially the measurement of harmonic and interharmonic in cyber-physical energy systems, are addressed in this paper. As new situations are introduced to the power system, the impact of electric vehicles, distributed generation and renewable energy has introduced extra demands to distributed sensors, waveform-level information and power quality data analytics. Harmonics and interharmonics, as the most significant disturbances, require carefully designed detection methods for an accurate measurement of electric loads whose information is crucial to subsequent analyzing and control. This paper gives a detailed description of the power quality analysis framework in networked environment and presents a fast and resolution-enhanced method for harmonic and interharmonic measurement. The proposed method first extracts harmonic and interharmonic components efficiently using the single-channel version of Robust Independent Component Analysis (RobustICA), then estimates the high-resolution frequency from three discrete Fourier transform (DFT) samples with little additional computation, and finally computes the amplitudes and phases with the adaptive linear neuron network. The experiments show that the proposed method is time-efficient and leads to a better accuracy of the simulated and experimental signals in the presence of noise and fundamental frequency deviation, thus providing a deeper insight into the (inter)harmonic sources or even the whole system.

Resolution-Enhanced Harmonic and Interharmonic Measurement for Power Quality Analysis in Cyber-Physical Energy System

PubMed Central

Liu, Yanchi; Wang, Xue; Liu, Youda; Cui, Sujin

2016-01-01

Power quality analysis issues, especially the measurement of harmonic and interharmonic in cyber-physical energy systems, are addressed in this paper. As new situations are introduced to the power system, the impact of electric vehicles, distributed generation and renewable energy has introduced extra demands to distributed sensors, waveform-level information and power quality data analytics. Harmonics and interharmonics, as the most significant disturbances, require carefully designed detection methods for an accurate measurement of electric loads whose information is crucial to subsequent analyzing and control. This paper gives a detailed description of the power quality analysis framework in networked environment and presents a fast and resolution-enhanced method for harmonic and interharmonic measurement. The proposed method first extracts harmonic and interharmonic components efficiently using the single-channel version of Robust Independent Component Analysis (RobustICA), then estimates the high-resolution frequency from three discrete Fourier transform (DFT) samples with little additional computation, and finally computes the amplitudes and phases with the adaptive linear neuron network. The experiments show that the proposed method is time-efficient and leads to a better accuracy of the simulated and experimental signals in the presence of noise and fundamental frequency deviation, thus providing a deeper insight into the (inter)harmonic sources or even the whole system. PMID:27355946

A novel LTE scheduling algorithm for green technology in smart grid.

PubMed

Hindia, Mohammad Nour; Reza, Ahmed Wasif; Noordin, Kamarul Ariffin; Chayon, Muhammad Hasibur Rashid

2015-01-01

Smart grid (SG) application is being used nowadays to meet the demand of increasing power consumption. SG application is considered as a perfect solution for combining renewable energy resources and electrical grid by means of creating a bidirectional communication channel between the two systems. In this paper, three SG applications applicable to renewable energy system, namely, distribution automation (DA), distributed energy system-storage (DER) and electrical vehicle (EV), are investigated in order to study their suitability in Long Term Evolution (LTE) network. To compensate the weakness in the existing scheduling algorithms, a novel bandwidth estimation and allocation technique and a new scheduling algorithm are proposed. The technique allocates available network resources based on application's priority, whereas the algorithm makes scheduling decision based on dynamic weighting factors of multi-criteria to satisfy the demands (delay, past average throughput and instantaneous transmission rate) of quality of service. Finally, the simulation results demonstrate that the proposed mechanism achieves higher throughput, lower delay and lower packet loss rate for DA and DER as well as provide a degree of service for EV. In terms of fairness, the proposed algorithm shows 3%, 7 % and 9% better performance compared to exponential rule (EXP-Rule), modified-largest weighted delay first (M-LWDF) and exponential/PF (EXP/PF), respectively.

A Novel LTE Scheduling Algorithm for Green Technology in Smart Grid

PubMed Central

Hindia, Mohammad Nour; Reza, Ahmed Wasif; Noordin, Kamarul Ariffin; Chayon, Muhammad Hasibur Rashid

2015-01-01

Smart grid (SG) application is being used nowadays to meet the demand of increasing power consumption. SG application is considered as a perfect solution for combining renewable energy resources and electrical grid by means of creating a bidirectional communication channel between the two systems. In this paper, three SG applications applicable to renewable energy system, namely, distribution automation (DA), distributed energy system-storage (DER) and electrical vehicle (EV), are investigated in order to study their suitability in Long Term Evolution (LTE) network. To compensate the weakness in the existing scheduling algorithms, a novel bandwidth estimation and allocation technique and a new scheduling algorithm are proposed. The technique allocates available network resources based on application’s priority, whereas the algorithm makes scheduling decision based on dynamic weighting factors of multi-criteria to satisfy the demands (delay, past average throughput and instantaneous transmission rate) of quality of service. Finally, the simulation results demonstrate that the proposed mechanism achieves higher throughput, lower delay and lower packet loss rate for DA and DER as well as provide a degree of service for EV. In terms of fairness, the proposed algorithm shows 3%, 7 % and 9% better performance compared to exponential rule (EXP-Rule), modified-largest weighted delay first (M-LWDF) and exponential/PF (EXP/PF), respectively. PMID:25830703

Equivalent model and power flow model for electric railway traction network

NASA Astrophysics Data System (ADS)

Wang, Feng

2018-05-01

An equivalent model of the Cable Traction Network (CTN) considering the distributed capacitance effect of the cable system is proposed. The model can be divided into 110kV side and 27.5kV side two kinds. The 110kV side equivalent model can be used to calculate the power supply capacity of the CTN. The 27.5kV side equivalent model can be used to solve the voltage of the catenary. Based on the equivalent simplified model of CTN, the power flow model of CTN which involves the reactive power compensation coefficient and the interaction of voltage and current, is derived.

Identifying Hydrologic Flowpaths on Arctic Hillslopes Using Electrical Resistivity and Self Potential

NASA Astrophysics Data System (ADS)

Voytek, E.; Rushlow, C. R.; Godsey, S.; Singha, K.

2015-12-01

Shallow subsurface flow is a dominant process controlling hillslope runoff generation, soil development, and solute reaction and transport. Despite their importance, the location and geometry of flowpaths are difficult to determine. In arctic environments, shallow subsurface flowpaths are limited to a thin zone of seasonal thaw above continuous permafrost, which is traditionally assumed to mimic to surface topography. Here we use a combined approach of electrical resistivity imaging (ERI) and self-potential measurements (SP) to map shallow subsurface flowpaths in and around water tracks, drainage features common to arctic hillslopes. ERI measurements delineate thawed zones in the subsurface that control flowpaths, while SP is sensitive to groundwater flow. We find that areas of low electrical resistivity in the water tracks are deeper than manual thaw depth estimates and variations from surface topography. This finding suggests that traditional techniques significantly underestimate active layer thaw and the extent of the flowpath network on arctic hillslopes. SP measurements identify complex 3-D flowpaths in the thawed zone. Our results lay the groundwork for investigations into the seasonal dynamics, hydrologic connectivity, and climate sensitivity of spatially distributed flowpath networks on arctic hillslopes.

Distributed Energy Resources Customer Adoption Model Plus (DER-CAM+), Version 1.0.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadler, Michael; Cardorso, Goncalo; Mashayekh, Salman

DER-CAM+ v1.0.0 is internally referred to as DER-CAM v5.0.0. Due to fundamental changes from previous versions, a new name (DER-CAM+) will be used for DER-CAM version 5.0.0 and above. DER-CAM+ is a Decision Support Tool for Decentralized Energy Systems that has been tailored for microgrid applications, and now explicitly considers electrical and thermal networks within a microgrid, ancillary services, and operating reserve. DER-CAM was initially created as an exclusively economic energy model, able to find the cost minimizing combination and operation profile of a set of DER technologies that meet energy loads of a building or microgrid for a typicalmore » test year. The previous versions of DER-CAM were formulated without modeling the electrical/thermal networks within the microgrid, and hence, used aggregate single-node approaches. Furthermore, they were not able to consider operating reserve constraints, and microgrid revenue streams from participating in ancillary services markets. This new version DER-CAM+ considers these issues by including electrical power flow and thermal flow equations and constraints in the microgrid, revenues from various ancillary services markets, and operating reserve constraints.« less

Power quality control of an autonomous wind-diesel power system based on hybrid intelligent controller.

PubMed

Ko, Hee-Sang; Lee, Kwang Y; Kang, Min-Jae; Kim, Ho-Chan

2008-12-01

Wind power generation is gaining popularity as the power industry in the world is moving toward more liberalized trade of energy along with public concerns of more environmentally friendly mode of electricity generation. The weakness of wind power generation is its dependence on nature-the power output varies in quite a wide range due to the change of wind speed, which is difficult to model and predict. The excess fluctuation of power output and voltages can influence negatively the quality of electricity in the distribution system connected to the wind power generation plant. In this paper, the authors propose an intelligent adaptive system to control the output of a wind power generation plant to maintain the quality of electricity in the distribution system. The target wind generator is a cost-effective induction generator, while the plant is equipped with a small capacity energy storage based on conventional batteries, heater load for co-generation and braking, and a voltage smoothing device such as a static Var compensator (SVC). Fuzzy logic controller provides a flexible controller covering a wide range of energy/voltage compensation. A neural network inverse model is designed to provide compensating control amount for a system. The system can be optimized to cope with the fluctuating market-based electricity price conditions to lower the cost of electricity consumption or to maximize the power sales opportunities from the wind generation plant.

Application of Artificial Neural Networks in the Heart Electrical Axis Position Conclusion Modeling

NASA Astrophysics Data System (ADS)

Bakanovskaya, L. N.

2016-08-01

The article touches upon building of a heart electrical axis position conclusion model using an artificial neural network. The input signals of the neural network are the values of deflections Q, R and S; and the output signal is the value of the heart electrical axis position. Training of the network is carried out by the error propagation method. The test results allow concluding that the created neural network makes a conclusion with a high degree of accuracy.

Distribution System Reliability Analysis for Smart Grid Applications

NASA Astrophysics Data System (ADS)

Aljohani, Tawfiq Masad

Reliability of power systems is a key aspect in modern power system planning, design, and operation. The ascendance of the smart grid concept has provided high hopes of developing an intelligent network that is capable of being a self-healing grid, offering the ability to overcome the interruption problems that face the utility and cost it tens of millions in repair and loss. To address its reliability concerns, the power utilities and interested parties have spent extensive amount of time and effort to analyze and study the reliability of the generation and transmission sectors of the power grid. Only recently has attention shifted to be focused on improving the reliability of the distribution network, the connection joint between the power providers and the consumers where most of the electricity problems occur. In this work, we will examine the effect of the smart grid applications in improving the reliability of the power distribution networks. The test system used in conducting this thesis is the IEEE 34 node test feeder, released in 2003 by the Distribution System Analysis Subcommittee of the IEEE Power Engineering Society. The objective is to analyze the feeder for the optimal placement of the automatic switching devices and quantify their proper installation based on the performance of the distribution system. The measures will be the changes in the reliability system indices including SAIDI, SAIFI, and EUE. The goal is to design and simulate the effect of the installation of the Distributed Generators (DGs) on the utility's distribution system and measure the potential improvement of its reliability. The software used in this work is DISREL, which is intelligent power distribution software that is developed by General Reliability Co.

An electrical-heating and self-sensing shape memory polymer composite incorporated with carbon fiber felt

NASA Astrophysics Data System (ADS)

Gong, Xiaobo; Liu, Liwu; Liu, Yanju; Leng, Jinsong

2016-03-01

Shape memory polymers (SMPs) have the ability to adjust their stiffness, lock a temporary shape, and recover the permanent shape upon imposing an appropriate stimulus. They have found their way into the field of morphing structures. The electrically Joule resistive heating of the conductive composite can be a desirable stimulus to activate the shape memory effect of SMPs without external heating equipment. Electro-induced SMP composites incorporated with carbon fiber felt (CFF) were explored in this work. The CFF is an excellent conductive filler which can easily spread throughout the composite. It has a huge advantage in terms of low cost, simple manufacturing process, and uniform and tunable temperature distribution while heating. A continuous and compact conductive network made of carbon fibers and the overlap joints among them was observed from the microscopy images, and this network contributes to the high conductive properties of the CFF/SMP composites. The CFF/SMP composites can be electrical-heated rapidly and uniformly, and its’ shape recovery effect can be actuated by the electrical resistance Joule heating of the CFF without an external heater. The CFF/SMP composite get higher modulus and higher strength than the pure SMP without losing any strain recovery property. The high dependence of temperature and strain on the electrical resistance also make the composite a good self-sensing material. In general, the CFF/SMP composite shows great prospects as a potential material for the future morphing structures.

Voltage regulation and power losses reduction in a wind farm integrated MV distribution network

NASA Astrophysics Data System (ADS)

Fandi, Ghaeth; Igbinovia, Famous Omar; Tlusty, Josef; Mahmoud, Rateb

2018-01-01

A medium-voltage (MV) wind production system is proposed in this paper. The system applies a medium-voltage permanent magnet synchronous generator (PMSG) as well as MV interconnection and distribution networks. The simulation scheme of an existing commercial electric-power system (Case A) and a proposed wind farm with a gearless PMSG insulated gate bipolar transistor (IGBT) power electronics converter scheme (Case B) is compared. The analyses carried out in MATLAB/Simulink environment shows an enhanced voltage profile and reduced power losses, thus, efficiency in installed IGBT power electronics devices in the wind farm. The resulting wind energy transformation scheme is a simple and controllable medium voltage application since it is not restrained by the IGBT power electronics voltage source converter (VSC) arrangement. Active and reactive power control is made possible with the aid of the gearless PMSG IGBT power converters.

Effects of Distributed Generation on Overcurrent Relay Coordination and an Adaptive Protection Scheme

NASA Astrophysics Data System (ADS)

Ilik, Semih C.; Arsoy, Aysen B.

2017-07-01

Integration of distributed generation (DG) such as renewable energy sources to electrical network becomes more prevalent in recent years. Grid connection of DG has effects on load flow directions, voltage profile, short circuit power and especially protection selectivity. Applying traditional overcurrent protection scheme is inconvenient when system reliability and sustainability are considered. If a fault happens in DG connected network, short circuit contribution of DG, creates additional branch element feeding the fault current; compels to consider directional overcurrent (OC) protection scheme. Protection coordination might get lost for changing working conditions when DG sources are connected. Directional overcurrent relay parameters are determined for downstream and upstream relays when different combinations of DG connected singular or plural, on radial test system. With the help of proposed flow chart, relay parameters are updated and coordination between relays kept sustained for different working conditions in DigSILENT PowerFactory program.

Network, system, and status software enhancements for the autonomously managed electrical power system breadboard. Volume 2: Protocol specification

NASA Technical Reports Server (NTRS)

Mckee, James W.

1990-01-01

This volume (2 of 4) contains the specification, structured flow charts, and code listing for the protocol. The purpose of an autonomous power system on a spacecraft is to relieve humans from having to continuously monitor and control the generation, storage, and distribution of power in the craft. This implies that algorithms will have been developed to monitor and control the power system. The power system will contain computers on which the algorithms run. There should be one control computer system that makes the high level decisions and sends commands to and receive data from the other distributed computers. This will require a communications network and an efficient protocol by which the computers will communicate. One of the major requirements on the protocol is that it be real time because of the need to control the power elements.

Virtual CO2 Emission Flows in the Global Electricity Trade Network.

PubMed

Qu, Shen; Li, Yun; Liang, Sai; Yuan, Jiahai; Xu, Ming

2018-06-05

Quantifying greenhouse gas emissions due to electricity consumption is crucial for climate mitigation in the electric power sector. Current practices primarily use production-based emission factors to quantify emissions for electricity consumption, assuming production and consumption of electricity take place within the same region. The increasingly intensified cross-border electricity trade complicates the accounting for emissions of electricity consumption. This study employs a network approach to account for the flows in the whole electricity trade network to estimate CO 2 emissions of electricity consumption for 137 major countries/regions in 2014. Results show that in some countries, especially those in Europe and Southern Africa, the impacts of electricity trade on the estimation of emission factors and embodied emissions are significant. The changes made to emission factors by considering intergrid electricity trade can have significant implications for emission accounting and climate mitigation when multiplied by total electricity consumption of the corresponding countries/regions.

Three Essays in Energy Economics and Industrial Organization, with Applications to Electricity and Distribution Networks

NASA Astrophysics Data System (ADS)

Dimitropoulos, Dimitrios

Electricity industries are experiencing upward cost pressures in many parts of the world. Chapter 1 of this thesis studies the production technology of electricity distributors. Although production and cost functions are mathematical duals, practitioners typically estimate only one or the other. This chapter proposes an approach for joint estimation of production and costs. Combining such quantity and price data has the effect of adding statistical information without introducing additional parameters into the model. We define a GMM estimator that produces internally consistent parameter estimates for both the production function and the cost function. We consider a multi-output framework, and show how to account for the presence of certain types of simultaneity and measurement error. The methodology is applied to data on 73 Ontario distributors for the period 2002-2012. As expected, the joint model results in a substantial improvement in the precision of parameter estimates. Chapter 2 focuses on productivity trends in electricity distribution. We apply two methodologies for estimating productivity growth . an index based approach, and an econometric cost based approach . to our data on the 73 Ontario distributors for the period 2002 to 2012. The resulting productivity growth estimates are approximately 1% per year, suggesting a reversal of the positive estimates that have generally been reported in previous periods. We implement flexible semi-parametric variants to assess the robustness of these conclusions and discuss the use of such statistical analyses for calibrating productivity and relative efficiencies within a price-cap framework. In chapter 3, I turn to the historically important problem of vertical contractual relations. While the existing literature has established that resale price maintenance is sufficient to coordinate the distribution network of a manufacturer, this chapter asks whether such vertical restraints are necessary. Specifically, I study the vertical contracting problem between an upstream manufacturer and its downstream distributors in a setting where spot market contracts fail, but resale price maintenance cannot be appealed to due to legal prohibition. I show that a bonus scheme based on retail revenues is sufficient to provide incentives to decentralized retailers to elicit the correct levels of both price and service.

Three Essays in Energy Economics and Industrial Organization, with Applications to Electricity and Distribution Networks

NASA Astrophysics Data System (ADS)

Dimitropoulos, Dimitrios

Electricity industries are experiencing upward cost pressures in many parts of the world. Chapter 1 of this thesis studies the production technology of electricity distributors. Although production and cost functions are mathematical duals, practitioners typically estimate only one or the other. This chapter proposes an approach for joint estimation of production and costs. Combining such quantity and price data has the effect of adding statistical information without introducing additional parameters into the model. We define a GMM estimator that produces internally consistent parameter estimates for both the production function and the cost function. We consider a multi-output framework, and show how to account for the presence of certain types of simultaneity and measurement error. The methodology is applied to data on 73 Ontario distributors for the period 2002-2012. As expected, the joint model results in a substantial improvement in the precision of parameter estimates. Chapter 2 focuses on productivity trends in electricity distribution. We apply two methodologies for estimating productivity growth---an index based approach, and an econometric cost based approach---to our data on the 73 Ontario distributors for the period 2002 to 2012. The resulting productivity growth estimates are approximately -1% per year, suggesting a reversal of the positive estimates that have generally been reported in previous periods. We implement flexible semi-parametric variants to assess the robustness of these conclusions and discuss the use of such statistical analyses for calibrating productivity and relative efficiencies within a price-cap framework. In chapter 3, I turn to the historically important problem of vertical contractual relations. While the existing literature has established that resale price maintenance is sufficient to coordinate the distribution network of a manufacturer, this chapter asks whether such vertical restraints are necessary. Specifically, I study the vertical contracting problem between an upstream manufacturer and its downstream distributors in a setting where spot market contracts fail, but resale price maintenance cannot be appealed to due to legal prohibition. I show that a bonus scheme based on retail revenues is sufficient to provide incentives to decentralized retailers to elicit the correct levels of both price and service.

Ship electric propulsion simulator based on networking technology

NASA Astrophysics Data System (ADS)

Zheng, Huayao; Huang, Xuewu; Chen, Jutao; Lu, Binquan

2006-11-01

According the new ship building tense, a novel electric propulsion simulator (EPS) had been developed in Marine Simulation Center of SMU. The architecture, software function and FCS network technology of EPS and integrated power system (IPS) were described. In allusion to the POD propeller in ship, a special physical model was built. The POD power was supplied from the simulative 6.6 kV Medium Voltage Main Switchboard, its control could be realized in local or remote mode. Through LAN, the simulated feature information of EPS will pass to the physical POD model, which would reflect the real thruster working status in different sea conditions. The software includes vessel-propeller math module, thruster control system, distribution and emergency integrated management, double closed loop control system, vessel static water resistance and dynamic software; instructor main control software. The monitor and control system is realized by real time data collection system and CAN bus technology. During the construction, most devices such as monitor panels and intelligent meters, are developed in lab which were based on embedded microcomputer system with CAN interface to link the network. They had also successfully used in practice and would be suitable for the future demands of digitalization ship.

Bioelectrical Signals and Ion Channels in the Modeling of Multicellular Patterns and Cancer Biophysics.

PubMed

Cervera, Javier; Alcaraz, Antonio; Mafe, Salvador

2016-02-04

Bioelectrical signals and ion channels are central to spatial patterns in cell ensembles, a problem of fundamental interest in positional information and cancer processes. We propose a model for electrically connected cells based on simple biological concepts: i) the membrane potential of a single cell characterizes its electrical state; ii) the long-range electrical coupling of the multicellular ensemble is realized by a network of gap junction channels between neighboring cells; and iii) the spatial distribution of an external biochemical agent can modify the conductances of the ion channels in a cell membrane and the multicellular electrical state. We focus on electrical effects in small multicellular ensembles, ignoring slow diffusional processes. The spatio-temporal patterns obtained for the local map of cell electric potentials illustrate the normalization of regions with abnormal cell electrical states. The effects of intercellular coupling and blocking of specific channels on the electrical patterns are described. These patterns can regulate the electrically-induced redistribution of charged nanoparticles over small regions of a model tissue. The inclusion of bioelectrical signals provides new insights for the modeling of cancer biophysics because collective multicellular states show electrical coupling mechanisms that are not readily deduced from biochemical descriptions at the individual cell level.

Bioelectrical Signals and Ion Channels in the Modeling of Multicellular Patterns and Cancer Biophysics

PubMed Central

Cervera, Javier; Alcaraz, Antonio; Mafe, Salvador

2016-01-01

Bioelectrical signals and ion channels are central to spatial patterns in cell ensembles, a problem of fundamental interest in positional information and cancer processes. We propose a model for electrically connected cells based on simple biological concepts: i) the membrane potential of a single cell characterizes its electrical state; ii) the long-range electrical coupling of the multicellular ensemble is realized by a network of gap junction channels between neighboring cells; and iii) the spatial distribution of an external biochemical agent can modify the conductances of the ion channels in a cell membrane and the multicellular electrical state. We focus on electrical effects in small multicellular ensembles, ignoring slow diffusional processes. The spatio-temporal patterns obtained for the local map of cell electric potentials illustrate the normalization of regions with abnormal cell electrical states. The effects of intercellular coupling and blocking of specific channels on the electrical patterns are described. These patterns can regulate the electrically-induced redistribution of charged nanoparticles over small regions of a model tissue. The inclusion of bioelectrical signals provides new insights for the modeling of cancer biophysics because collective multicellular states show electrical coupling mechanisms that are not readily deduced from biochemical descriptions at the individual cell level. PMID:26841954

Bioelectrical Signals and Ion Channels in the Modeling of Multicellular Patterns and Cancer Biophysics

NASA Astrophysics Data System (ADS)

Cervera, Javier; Alcaraz, Antonio; Mafe, Salvador

2016-02-01

Bioelectrical signals and ion channels are central to spatial patterns in cell ensembles, a problem of fundamental interest in positional information and cancer processes. We propose a model for electrically connected cells based on simple biological concepts: i) the membrane potential of a single cell characterizes its electrical state; ii) the long-range electrical coupling of the multicellular ensemble is realized by a network of gap junction channels between neighboring cells; and iii) the spatial distribution of an external biochemical agent can modify the conductances of the ion channels in a cell membrane and the multicellular electrical state. We focus on electrical effects in small multicellular ensembles, ignoring slow diffusional processes. The spatio-temporal patterns obtained for the local map of cell electric potentials illustrate the normalization of regions with abnormal cell electrical states. The effects of intercellular coupling and blocking of specific channels on the electrical patterns are described. These patterns can regulate the electrically-induced redistribution of charged nanoparticles over small regions of a model tissue. The inclusion of bioelectrical signals provides new insights for the modeling of cancer biophysics because collective multicellular states show electrical coupling mechanisms that are not readily deduced from biochemical descriptions at the individual cell level.

Multiport power router and its impact on future smart grids

NASA Astrophysics Data System (ADS)

Kado, Yuichi; Shichijo, Daiki; Wada, Keiji; Iwatsuki, Katsumi

2016-07-01

We propose a Y configuration power router as a unit cell to easily construct a power delivery system that can meet many types of user requirements. The Y configuration power router controls the direction and magnitude of power flows between three ports regardless of DC or AC. We constructed a prototype three-way isolated DC/DC converter that is the core unit of the Y configuration power router. The electrical insulation between three ports assures safety and reliability for power network systems. We then tested the operation of power flow control. The experimental results revealed that our methodology based on a governing equation was appropriate to control the power flow of the three-way DC/DC converter. In addition, a distribution network composed of power routers had the ability to easily enable interchanges of electrical power between autonomous microgrid cells. We also explored the requirements for communication between energy routers to achieve dynamic adjustments of energy flows in a coordinated manner and their impact on resilient power grid systems.

Defects formation and wave emitting from defects in excitable media

NASA Astrophysics Data System (ADS)

Ma, Jun; Xu, Ying; Tang, Jun; Wang, Chunni

2016-05-01

Abnormal electrical activities in neuronal system could be associated with some neuronal diseases. Indeed, external forcing can cause breakdown even collapse in nervous system under appropriate condition. The excitable media sometimes could be described by neuronal network with different topologies. The collective behaviors of neurons can show complex spatiotemporal dynamical properties and spatial distribution for electrical activities due to self-organization even from the regulating from central nervous system. Defects in the nervous system can emit continuous waves or pulses, and pacemaker-like source is generated to perturb the normal signal propagation in nervous system. How these defects are developed? In this paper, a network of neurons is designed in two-dimensional square array with nearest-neighbor connection type; the formation mechanism of defects is investigated by detecting the wave propagation induced by external forcing. It is found that defects could be induced under external periodical forcing under the boundary, and then the wave emitted from the defects can keep balance with the waves excited from external forcing.

Evaluating North American Electric Grid Reliability Using the Barabasi-Albert Network Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chassin, David P.; Posse, Christian

2005-09-15

The reliability of electric transmission systems is examined using a scale-free model of network topology and failure propagation. The topologies of the North American eastern and western electric grids are analyzed to estimate their reliability based on the Barabási-Albert network model. A commonly used power system reliability index is computed using a simple failure propagation model. The results are compared to the values of power system reliability indices previously obtained using other methods and they suggest that scale-free network models are usable to estimate aggregate electric grid reliability.

Evaluating North American Electric Grid Reliability Using the Barabasi-Albert Network Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chassin, David P.; Posse, Christian

2005-09-15

The reliability of electric transmission systems is examined using a scale-free model of network topology and failure propagation. The topologies of the North American eastern and western electric grids are analyzed to estimate their reliability based on the Barabasi-Albert network model. A commonly used power system reliability index is computed using a simple failure propagation model. The results are compared to the values of power system reliability indices previously obtained using standard power engineering methods, and they suggest that scale-free network models are usable to estimate aggregate electric grid reliability.

Effects of magnetic fields during high voltage live-line maintenance

NASA Astrophysics Data System (ADS)

Göcsei, Gábor; Kiss, István, Dr; Németh, Bálint

2015-10-01

In case of transmission and distribution networks, extra low frequency (typically 50 or 60 Hz) electric and magnetic fields have to be taken into consideration separately from each other. Health effects have been documented from exposures to both types of fields. Magnetic fields are qualified as possibly carcinogenic to humans (category “2B”) by WHO's cancer research institute, International Agency for Research on Cancer (IARC), so it is essential to protect the workers against their harmful effects. During live-line maintenance (LLM) electric fields can be shielded effectively by different kinds of conductive clothing, which are enclosed metal surfaces acting as a Faraday-cage. In practice laboratory measurements also prove their efficiency, the required shielding ratio is above 99% by the related standard.. A set of measurements have proved that regular conductive clothing used against the electric fields cannot shield the magnetic fields effectively at all. This paper introduces the possible risks of LLM from the aspect of the health effects of magnetic fields. Although in this case the principle of shielding the electric fields cannot be applied, new considerations in equipment design and technology can be used as a possible solution. Calculations and simulations based on the data of the Hungarian transmission network - which represents the European grid as a part of ENTSO-E - and high-current laboratory measurement results also prove the importance of the topic.

Against the grain: The physical properties of anisotropic partially molten rocks

NASA Astrophysics Data System (ADS)

Ghanbarzadeh, S.; Hesse, M. A.; Prodanovic, M.

2014-12-01

Partially molten rocks commonly develop textures that appear close to textural equilibrium, where the melt network evolves to minimize the energy of the melt-solid interfaces, while maintaining the dihedral angle θ at solid-solid-melt contact lines. Textural equilibrium provides a powerful model for the melt distribution that controls the petro-physical properties of partially molten rocks, e.g., permeability, elastic moduli, and electrical resistivity. We present the first level-set computations of three-dimensional texturally equilibrated melt networks in rocks with an anisotropic fabric. Our results show that anisotropy induces wetting of smaller grain boundary faces for θ > 0 at realistic porosities ϕ < 3%. This was previously not thought to be possible at textural equilibrium and reconciles the theory with experimental observations. Wetting of the grain boundary faces leads to a dramatic redistribution of the melt from the edges to the faces that introduces strong anisotropy in the petro-physical properties such as permeability, effective electrical conductivity and mechanical properties. Figure, on left, shows that smaller grain boundaries become wetted at relatively low melt fractions of 3% in stretched polyhedral grains with elongation factor 1.5. Right plot represents the ratio of melt electrical conductivity to effective conductivity of medium (known as formation factor) as an example of anisotropy in physical properties. The plot shows that even slight anisotropy in grains induces considerable anisotropy in electrical properties.

Design of pressure-driven microfluidic networks using electric circuit analogy.

PubMed

Oh, Kwang W; Lee, Kangsun; Ahn, Byungwook; Furlani, Edward P

2012-02-07

This article reviews the application of electric circuit methods for the analysis of pressure-driven microfluidic networks with an emphasis on concentration- and flow-dependent systems. The application of circuit methods to microfluidics is based on the analogous behaviour of hydraulic and electric circuits with correlations of pressure to voltage, volumetric flow rate to current, and hydraulic to electric resistance. Circuit analysis enables rapid predictions of pressure-driven laminar flow in microchannels and is very useful for designing complex microfluidic networks in advance of fabrication. This article provides a comprehensive overview of the physics of pressure-driven laminar flow, the formal analogy between electric and hydraulic circuits, applications of circuit theory to microfluidic network-based devices, recent development and applications of concentration- and flow-dependent microfluidic networks, and promising future applications. The lab-on-a-chip (LOC) and microfluidics community will gain insightful ideas and practical design strategies for developing unique microfluidic network-based devices to address a broad range of biological, chemical, pharmaceutical, and other scientific and technical challenges.

A distributed big data storage and data mining framework for solar-generated electricity quantity forecasting

NASA Astrophysics Data System (ADS)

Wang, Jianzong; Chen, Yanjun; Hua, Rui; Wang, Peng; Fu, Jia

2012-02-01

Photovoltaic is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material. Due to the growing demand for renewable energy sources, the manufacturing of solar cells and photovoltaic arrays has advanced considerably in recent years. Solar photovoltaics are growing rapidly, albeit from a small base, to a total global capacity of 40,000 MW at the end of 2010. More than 100 countries use solar photovoltaics. Driven by advances in technology and increases in manufacturing scale and sophistication, the cost of photovoltaic has declined steadily since the first solar cells were manufactured. Net metering and financial incentives, such as preferential feed-in tariffs for solar-generated electricity; have supported solar photovoltaics installations in many countries. However, the power that generated by solar photovoltaics is affected by the weather and other natural factors dramatically. To predict the photovoltaic energy accurately is of importance for the entire power intelligent dispatch in order to reduce the energy dissipation and maintain the security of power grid. In this paper, we have proposed a big data system--the Solar Photovoltaic Power Forecasting System, called SPPFS to calculate and predict the power according the real-time conditions. In this system, we utilized the distributed mixed database to speed up the rate of collecting, storing and analysis the meteorological data. In order to improve the accuracy of power prediction, the given neural network algorithm has been imported into SPPFS.By adopting abundant experiments, we shows that the framework can provide higher forecast accuracy-error rate less than 15% and obtain low latency of computing by deploying the mixed distributed database architecture for solar-generated electricity.

Proceedings of the American Power Conference. Volume 58-I

DOE Office of Scientific and Technical Information (OSTI.GOV)

McBride, A.E.

1996-10-01

This is volume 58-I of the proceedings of the American Power Conference, 1996, Technology for Competition and Globalization. The topics of the papers include power plant DC issues; cost of environmental compliance; advanced coal systems -- environmental performance; technology for competition in dispersed generation; superconductivity technologies for electric utility applications; power generation trends and challenges in China; aging in nuclear power plants; innovative and competitive repowering options; structural examinations, modifications and repairs; electric load forecasting; distribution planning; EMF effects; fuzzy logic and neural networks for power plant applications; electrokinetic decontamination of soils; integrated gasification combined cycle; advances in fusion; coolingmore » towers; relays; plant controls; flue gas desulfurization; waste product utilization; and improved technologies.« less

MQW Optical Feedback Modulators And Phase Shifters

NASA Technical Reports Server (NTRS)

Jackson, Deborah J.

1995-01-01

Laser diodes equipped with proposed multiple-quantum-well (MQW) optical feedback modulators prove useful in variety of analog and digital optical-communication applications, including fiber-optic signal-distribution networks and high-speed, low-crosstalk interconnections among super computers or very-high-speed integrated circuits. Development exploits accompanying electro-optical aspect of QCSE - variation in index of refraction with applied electric field. Also exploits sensitivity of laser diodes to optical feedback. Approach is reverse of prior approach.

A comprehensive WSN-based approach to efficiently manage a Smart Grid.

PubMed

Martinez-Sandoval, Ruben; Garcia-Sanchez, Antonio-Javier; Garcia-Sanchez, Felipe; Garcia-Haro, Joan; Flynn, David

2014-10-10

The Smart Grid (SG) is conceived as the evolution of the current electrical grid representing a big leap in terms of efficiency, reliability and flexibility compared to today's electrical network. To achieve this goal, the Wireless Sensor Networks (WSNs) are considered by the scientific/engineering community to be one of the most suitable technologies to apply SG technology to due to their low-cost, collaborative and long-standing nature. However, the SG has posed significant challenges to utility operators-mainly very harsh radio propagation conditions and the lack of appropriate systems to empower WSN devices-making most of the commercial widespread solutions inadequate. In this context, and as a main contribution, we have designed a comprehensive ad-hoc WSN-based solution for the Smart Grid (SENSED-SG) that focuses on specific implementations of the MAC, the network and the application layers to attain maximum performance and to successfully deal with any arising hurdles. Our approach has been exhaustively evaluated by computer simulations and mathematical analysis, as well as validation within real test-beds deployed in controlled environments. In particular, these test-beds cover two of the main scenarios found in a SG; on one hand, an indoor electrical substation environment, implemented in a High Voltage AC/DC laboratory, and, on the other hand, an outdoor case, deployed in the Transmission and Distribution segment of a power grid. The results obtained show that SENSED-SG performs better and is more suitable for the Smart Grid than the popular ZigBee WSN approach.

Intraoperative dorsal language network mapping by using single-pulse electrical stimulation.

PubMed

Yamao, Yukihiro; Matsumoto, Riki; Kunieda, Takeharu; Arakawa, Yoshiki; Kobayashi, Katsuya; Usami, Kiyohide; Shibata, Sumiya; Kikuchi, Takayuki; Sawamoto, Nobukatsu; Mikuni, Nobuhiro; Ikeda, Akio; Fukuyama, Hidenao; Miyamoto, Susumu

2014-09-01

The preservation of language function during brain surgery still poses a challenge. No intraoperative methods have been established to monitor the language network reliably. We aimed to establish intraoperative language network monitoring by means of cortico-cortical evoked potentials (CCEPs). Subjects were six patients with tumors located close to the arcuate fasciculus (AF) in the language-dominant left hemisphere. Under general anesthesia, the anterior perisylvian language area (AL) was first defined by the CCEP connectivity patterns between the ventrolateral frontal and temporoparietal area, and also by presurgical neuroimaging findings. We then monitored the integrity of the language network by stimulating AL and by recording CCEPs from the posterior perisylvian language area (PL) consecutively during both general anesthesia and awake condition. High-frequency electrical stimulation (ES) performed during awake craniotomy confirmed language function at AL in all six patients. Despite an amplitude decline (≤32%) in two patients, CCEP monitoring successfully prevented persistent language impairment. After tumor removal, single-pulse ES was applied to the white matter tract beneath the floor of the removal cavity in five patients, in order to trace its connections into the language cortices. In three patients in whom high-frequency ES of the white matter produced naming impairment, this "eloquent" subcortical site directly connected AL and PL, judging from the latencies and distributions of cortico- and subcortico-cortical evoked potentials. In conclusion, this study provided the direct evidence that AL, PL, and AF constitute the dorsal language network. Intraoperative CCEP monitoring is clinically useful for evaluating the integrity of the language network. Copyright © 2014 Wiley Periodicals, Inc.

Self-assembled tunable networks of sticky colloidal particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demortiere, Arnaud; Snezhko, Oleksiy Alexey; Sapozhnikov, Maksim

Self-assembled tunable networks of microscopic polymer fibers ranging from wavy colloidal "fur" to highly interconnected networks are created from polymer systems and an applied electric field. The networks emerge via dynamic self-assembly in an alternating (ac) electric field from a non-aqueous suspension of "sticky" polymeric colloidal particles with a controlled degree of polymerization. The resulting architectures are tuned by the frequency and amplitude of the electric field and surface properties of the particles.

International Review of Standards and Labeling Programs for Distribution Transformers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Letschert, Virginie; Scholand, Michael; Carreño, Ana María

Transmission and distribution (T&D) losses in electricity networks represent 8.5% of final energy consumption in the world. In Latin America, T&D losses range between 6% and 20% of final energy consumption, and represent 7% in Chile. Because approximately one-third of T&D losses take place in distribution transformers alone, there is significant potential to save energy and reduce costs and carbon emissions through policy intervention to increase distribution transformer efficiency. A large number of economies around the world have recognized the significant impact of addressing distribution losses and have implemented policies to support market transformation towards more efficient distribution transformers. Asmore » a result, there is considerable international experience to be shared and leveraged to inform countries interested in reducing distribution losses through policy intervention. The report builds upon past international studies of standards and labeling (S&L) programs for distribution transformers to present the current energy efficiency programs for distribution transformers around the world.« less

Complete characterization of the stability of cluster synchronization in complex dynamical networks.

PubMed

Sorrentino, Francesco; Pecora, Louis M; Hagerstrom, Aaron M; Murphy, Thomas E; Roy, Rajarshi

2016-04-01

Synchronization is an important and prevalent phenomenon in natural and engineered systems. In many dynamical networks, the coupling is balanced or adjusted to admit global synchronization, a condition called Laplacian coupling. Many networks exhibit incomplete synchronization, where two or more clusters of synchronization persist, and computational group theory has recently proved to be valuable in discovering these cluster states based on the topology of the network. In the important case of Laplacian coupling, additional synchronization patterns can exist that would not be predicted from the group theory analysis alone. Understanding how and when clusters form, merge, and persist is essential for understanding collective dynamics, synchronization, and failure mechanisms of complex networks such as electric power grids, distributed control networks, and autonomous swarming vehicles. We describe a method to find and analyze all of the possible cluster synchronization patterns in a Laplacian-coupled network, by applying methods of computational group theory to dynamically equivalent networks. We present a general technique to evaluate the stability of each of the dynamically valid cluster synchronization patterns. Our results are validated in an optoelectronic experiment on a five-node network that confirms the synchronization patterns predicted by the theory.

Stochastic resonance enhancement of small-world neural networks by hybrid synapses and time delay

NASA Astrophysics Data System (ADS)

Yu, Haitao; Guo, Xinmeng; Wang, Jiang

2017-01-01

The synergistic effect of hybrid electrical-chemical synapses and information transmission delay on the stochastic response behavior in small-world neuronal networks is investigated. Numerical results show that, the stochastic response behavior can be regulated by moderate noise intensity to track the rhythm of subthreshold pacemaker, indicating the occurrence of stochastic resonance (SR) in the considered neural system. Inheriting the characteristics of two types of synapses-electrical and chemical ones, neural networks with hybrid electrical-chemical synapses are of great improvement in neuron communication. Particularly, chemical synapses are conducive to increase the network detectability by lowering the resonance noise intensity, while the information is better transmitted through the networks via electrical coupling. Moreover, time delay is able to enhance or destroy the periodic stochastic response behavior intermittently. In the time-delayed small-world neuronal networks, the introduction of electrical synapses can significantly improve the signal detection capability by widening the range of optimal noise intensity for the subthreshold signal, and the efficiency of SR is largely amplified in the case of pure chemical couplings. In addition, the stochastic response behavior is also profoundly influenced by the network topology. Increasing the rewiring probability in pure chemically coupled networks can always enhance the effect of SR, which is slightly influenced by information transmission delay. On the other hand, the capacity of information communication is robust to the network topology within the time-delayed neuronal systems including electrical couplings.

Prediction of Industrial Electric Energy Consumption in Anhui Province Based on GA-BP Neural Network

NASA Astrophysics Data System (ADS)

Zhang, Jiajing; Yin, Guodong; Ni, Youcong; Chen, Jinlan

2018-01-01

In order to improve the prediction accuracy of industrial electrical energy consumption, a prediction model of industrial electrical energy consumption was proposed based on genetic algorithm and neural network. The model use genetic algorithm to optimize the weights and thresholds of BP neural network, and the model is used to predict the energy consumption of industrial power in Anhui Province, to improve the prediction accuracy of industrial electric energy consumption in Anhui province. By comparing experiment of GA-BP prediction model and BP neural network model, the GA-BP model is more accurate with smaller number of neurons in the hidden layer.

Smart Grid Enabled EVSE

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

2015-01-12

The combined team of GE Global Research, Federal Express, National Renewable Energy Laboratory, and Consolidated Edison has successfully achieved the established goals contained within the Department of Energy’s Smart Grid Capable Electric Vehicle Supply Equipment funding opportunity. The final program product, shown charging two vehicles in Figure 1, reduces by nearly 50% the total installed system cost of the electric vehicle supply equipment (EVSE) as well as enabling a host of new Smart Grid enabled features. These include bi-directional communications, load control, utility message exchange and transaction management information. Using the new charging system, Utilities or energy service providers willmore » now be able to monitor transportation related electrical loads on their distribution networks, send load control commands or preferences to individual systems, and then see measured responses. Installation owners will be able to authorize usage of the stations, monitor operations, and optimally control their electricity consumption. These features and cost reductions have been developed through a total system design solution.« less

Networked Microgrids for Self-healing Power Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhaoyu; Chen, Bokan; Wang, Jianhui

This paper proposes a transformative architecture for the normal operation and self-healing of networked microgrids (MGs). MGs can support and interchange electricity with each other in the proposed infrastructure. The networked MGs are connected by a physical common bus and a designed two-layer cyber communication network. The lower layer is within each MG where the energy management system (EMS) schedules the MG operation; the upper layer links a number of EMSs for global optimization and communication. In the normal operation mode, the objective is to schedule dispatchable distributed generators (DGs), energy storage systems (ESs) and controllable loads to minimize themore » operation costs and maximize the supply adequacy of each MG. When a generation deficiency or fault happens in a MG, the model switches to the self-healing mode and the local generation capacities of other MGs can be used to support the on-emergency portion of the system. A consensus algorithm is used to distribute portions of the desired power support to each individual MG in a decentralized way. The allocated portion corresponds to each MG’s local power exchange target which is used by its EMS to perform the optimal schedule. The resultant aggregated power output of networked MGs will be used to provide the requested power support. Test cases demonstrate the effectiveness of the proposed methodology.« less

Analysis of the resistive network in a bio-inspired CMOS vision chip

NASA Astrophysics Data System (ADS)

Kong, Jae-Sung; Sung, Dong-Kyu; Hyun, Hyo-Young; Shin, Jang-Kyoo

2007-12-01

CMOS vision chips for edge detection based on a resistive circuit have recently been developed. These chips help develop neuromorphic systems with a compact size, high speed of operation, and low power dissipation. The output of the vision chip depends dominantly upon the electrical characteristics of the resistive network which consists of a resistive circuit. In this paper, the body effect of the MOSFET for current distribution in a resistive circuit is discussed with a simple model. In order to evaluate the model, two 160×120 CMOS vision chips have been fabricated by using a standard CMOS technology. The experimental results have been nicely matched with our prediction.

Robustness of a multimodal piezoelectric damping involving the electrical analogue of a plate

NASA Astrophysics Data System (ADS)

Lossouarn, Boris; Cunefare, Kenneth A.; Aucejo, Mathieu; Deü, Jean-François

2016-04-01

Multimodal passive damping of a mechanical structure can be implemented by a coupling to a secondary structure exhibiting similar modal properties. When considering a piezoelectric coupling, the secondary structure is an electrical network. A suitable topology for such a network can be obtained by a finite difference formulation of the mechanical equations, followed by a direct electromechanical analogy. This procedure is applied to the Kirchhoff-Love theory in order to find the electrical analogue of a clamped plate. The passive electrical network is implemented with inductors, transformers and the inherent capacitance of the piezoelectric patches. The electrical resonances are tuned to approach those of several mechanical modes simultaneously. This yields a broadband reduction of the plate vibrations through the array of interconnected piezoelectric patches. The robustness of the control strategy is evaluated by introducing perturbations in the mechanical or electrical designs. A non-optimal tuning is considered by way of a uniform variation of the network inductance. Then, the effect of local or boundary modifications of the electromechanical system is observed experimentally. In the end, the use of an analogous electrical network appears as an efficient and robust solution for the multimodal control of a plate.

Energy management of a university campus utilizing short-term load forecasting with an artificial neural network

NASA Astrophysics Data System (ADS)

Palchak, David

Electrical load forecasting is a tool that has been utilized by distribution designers and operators as a means for resource planning and generation dispatch. The techniques employed in these predictions are proving useful in the growing market of consumer, or end-user, participation in electrical energy consumption. These predictions are based on exogenous variables, such as weather, and time variables, such as day of week and time of day as well as prior energy consumption patterns. The participation of the end-user is a cornerstone of the Smart Grid initiative presented in the Energy Independence and Security Act of 2007, and is being made possible by the emergence of enabling technologies such as advanced metering infrastructure. The optimal application of the data provided by an advanced metering infrastructure is the primary motivation for the work done in this thesis. The methodology for using this data in an energy management scheme that utilizes a short-term load forecast is presented. The objective of this research is to quantify opportunities for a range of energy management and operation cost savings of a university campus through the use of a forecasted daily electrical load profile. The proposed algorithm for short-term load forecasting is optimized for Colorado State University's main campus, and utilizes an artificial neural network that accepts weather and time variables as inputs. The performance of the predicted daily electrical load is evaluated using a number of error measurements that seek to quantify the best application of the forecast. The energy management presented utilizes historical electrical load data from the local service provider to optimize the time of day that electrical loads are being managed. Finally, the utilization of forecasts in the presented energy management scenario is evaluated based on cost and energy savings.

District heating and cooling systems for communities through power plant retrofit distribution network. Volume 3. Final report, September 1, 1978-May 31, 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

This final report of Phase I of the study presents Task 4, Technical Review and Assessment. The most-promising district-heating concept identified in the Phase I study for the Public Service Electric and Gas Company, Newark, New Jersey, is a hot-water system in which steam is extracted from an existing turbine and used to drive a new, small backpressure turbine-generator. The backpressure turbine provides heat for district heating and simultaneously provides additional electric-generating capacity to partially offset the capacity lost due to the steam extraction. This approach is the most-economical way to retrofit the stations studied for district heating while minimizingmore » electric-capacity loss. Nine fossil-fuel-fired stations within the PSE and G system were evaluated for possibly supplying heat for district heating and cooling in cogeneration operations, but only three were selected to supply the district-heating steam. They are Essex, Hudson, and Bergen. Plant retrofit, thermal distribution schemes, consumer-conversion scheme, and consumer-metering system are discussed. Extensive technical information is provided in 16 appendices, additional tables, figures, and drawings. (MCW)« less

Design, Specification, and Synthesis of Aircraft Electric Power Systems Control Logic

NASA Astrophysics Data System (ADS)

Xu, Huan

Cyber-physical systems integrate computation, networking, and physical processes. Substantial research challenges exist in the design and verification of such large-scale, distributed sensing, actuation, and control systems. Rapidly improving technology and recent advances in control theory, networked systems, and computer science give us the opportunity to drastically improve our approach to integrated flow of information and cooperative behavior. Current systems rely on text-based specifications and manual design. Using new technology advances, we can create easier, more efficient, and cheaper ways of developing these control systems. This thesis will focus on design considerations for system topologies, ways to formally and automatically specify requirements, and methods to synthesize reactive control protocols, all within the context of an aircraft electric power system as a representative application area. This thesis consists of three complementary parts: synthesis, specification, and design. The first section focuses on the synthesis of central and distributed reactive controllers for an aircraft elec- tric power system. This approach incorporates methodologies from computer science and control. The resulting controllers are correct by construction with respect to system requirements, which are formulated using the specification language of linear temporal logic (LTL). The second section addresses how to formally specify requirements and introduces a domain-specific language for electric power systems. A software tool automatically converts high-level requirements into LTL and synthesizes a controller. The final sections focus on design space exploration. A design methodology is proposed that uses mixed-integer linear programming to obtain candidate topologies, which are then used to synthesize controllers. The discrete-time control logic is then verified in real-time by two methods: hardware and simulation. Finally, the problem of partial observability and dynamic state estimation is explored. Given a set placement of sensors on an electric power system, measurements from these sensors can be used in conjunction with control logic to infer the state of the system.

The application of the multi-alternative approach in active neural network models

NASA Astrophysics Data System (ADS)

Podvalny, S.; Vasiljev, E.

2017-02-01

The article refers to the construction of intelligent systems based artificial neuron networks are used. We discuss the basic properties of the non-compliance of artificial neuron networks and their biological prototypes. It is shown here that the main reason for these discrepancies is the structural immutability of the neuron network models in the learning process, that is, their passivity. Based on the modern understanding of the biological nervous system as a structured ensemble of nerve cells, it is proposed to abandon the attempts to simulate its work at the level of the elementary neurons functioning processes and proceed to the reproduction of the information structure of data storage and processing on the basis of the general enough evolutionary principles of multialternativity, i.e. the multi-level structural model, diversity and modularity. The implementation method of these principles is offered, using the faceted memory organization in the neuron network with the rearranging active structure. An example of the implementation of the active facet-type neuron network in the intellectual decision-making system in the conditions of critical events development in the electrical distribution system.

Graph Design via Convex Optimization: Online and Distributed Perspectives

NASA Astrophysics Data System (ADS)

Meng, De

Network and graph have long been natural abstraction of relations in a variety of applications, e.g. transportation, power system, social network, communication, electrical circuit, etc. As a large number of computation and optimization problems are naturally defined on graphs, graph structures not only enable important properties of these problems, but also leads to highly efficient distributed and online algorithms. For example, graph separability enables the parallelism for computation and operation as well as limits the size of local problems. More interestingly, graphs can be defined and constructed in order to take best advantage of those problem properties. This dissertation focuses on graph structure and design in newly proposed optimization problems, which establish a bridge between graph properties and optimization problem properties. We first study a new optimization problem called Geodesic Distance Maximization Problem (GDMP). Given a graph with fixed edge weights, finding the shortest path, also known as the geodesic, between two nodes is a well-studied network flow problem. We introduce the Geodesic Distance Maximization Problem (GDMP): the problem of finding the edge weights that maximize the length of the geodesic subject to convex constraints on the weights. We show that GDMP is a convex optimization problem for a wide class of flow costs, and provide a physical interpretation using the dual. We present applications of the GDMP in various fields, including optical lens design, network interdiction, and resource allocation in the control of forest fires. We develop an Alternating Direction Method of Multipliers (ADMM) by exploiting specific problem structures to solve large-scale GDMP, and demonstrate its effectiveness in numerical examples. We then turn our attention to distributed optimization on graph with only local communication. Distributed optimization arises in a variety of applications, e.g. distributed tracking and localization, estimation problems in sensor networks, multi-agent coordination. Distributed optimization aims to optimize a global objective function formed by summation of coupled local functions over a graph via only local communication and computation. We developed a weighted proximal ADMM for distributed optimization using graph structure. This fully distributed, single-loop algorithm allows simultaneous updates and can be viewed as a generalization of existing algorithms. More importantly, we achieve faster convergence by jointly designing graph weights and algorithm parameters. Finally, we propose a new problem on networks called Online Network Formation Problem: starting with a base graph and a set of candidate edges, at each round of the game, player one first chooses a candidate edge and reveals it to player two, then player two decides whether to accept it; player two can only accept limited number of edges and make online decisions with the goal to achieve the best properties of the synthesized network. The network properties considered include the number of spanning trees, algebraic connectivity and total effective resistance. These network formation games arise in a variety of cooperative multiagent systems. We propose a primal-dual algorithm framework for the general online network formation game, and analyze the algorithm performance by the competitive ratio and regret.

Network model of bilateral power markets based on complex networks

NASA Astrophysics Data System (ADS)

Wu, Yang; Liu, Junyong; Li, Furong; Yan, Zhanxin; Zhang, Li

2014-06-01

The bilateral power transaction (BPT) mode becomes a typical market organization with the restructuring of electric power industry, the proper model which could capture its characteristics is in urgent need. However, the model is lacking because of this market organization's complexity. As a promising approach to modeling complex systems, complex networks could provide a sound theoretical framework for developing proper simulation model. In this paper, a complex network model of the BPT market is proposed. In this model, price advantage mechanism is a precondition. Unlike other general commodity transactions, both of the financial layer and the physical layer are considered in the model. Through simulation analysis, the feasibility and validity of the model are verified. At same time, some typical statistical features of BPT network are identified. Namely, the degree distribution follows the power law, the clustering coefficient is low and the average path length is a bit long. Moreover, the topological stability of the BPT network is tested. The results show that the network displays a topological robustness to random market member's failures while it is fragile against deliberate attacks, and the network could resist cascading failure to some extent. These features are helpful for making decisions and risk management in BPT markets.

Multimodal vibration damping of a plate by piezoelectric coupling to its analogous electrical network

NASA Astrophysics Data System (ADS)

Lossouarn, B.; Deü, J.-F.; Aucejo, M.; Cunefare, K. A.

2016-11-01

Multimodal damping can be achieved by coupling a mechanical structure to an electrical network exhibiting similar modal properties. Focusing on a plate, a new topology for such an electrical analogue is found from a finite difference approximation of the Kirchhoff-Love theory and the use of the direct electromechanical analogy. Discrete models based on element dynamic stiffness matrices are proposed to simulate square plate unit cells coupled to their electrical analogues through two-dimensional piezoelectric transducers. A setup made of a clamped plate covered with an array of piezoelectric patches is built in order to validate the control strategy and the numerical models. The analogous electrical network is implemented with passive components as inductors, transformers and the inherent capacitance of the piezoelectric patches. The effect of the piezoelectric coupling on the dynamics of the clamped plate is significant as it creates the equivalent of a multimodal tuned mass damping. An adequate tuning of the network then yields a broadband vibration reduction. In the end, the use of an analogous electrical network appears as an efficient solution for the multimodal control of a plate.

A Micro grid design for a kind of household energy efficiency management system based on high permeability

NASA Astrophysics Data System (ADS)

Li, Siwei; Li, Jun; Liu, Zhuochu; Wang, Min; Yue, Liang

2017-05-01

After the access of household distributed photovoltaic, conditions of high permeability generally occur, which cut off the connection between distributed power supply and major network rapidly and use energy storage device to realize electrical energy storage. The above operations cannot be adequate for the power grid health after distributed power supply access any more from the perspective of economy and rationality. This paper uses the integration between device and device, integration between device and system and integration between system and system of household microgrid and household energy efficiency management, to design household microgrid building program and operation strategy containing household energy efficiency management, to achieve efficient integration of household energy efficiency management and household microgrid, to effectively solve problems of high permeability of household distributed power supply and so on.

AUTOMATED UTILITY SERVICE AREA ASSESSMENT UNDER EMERGENCY CONDITIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

G. TOOLE; S. LINGER

2001-01-01

All electric utilities serve power to their customers through a variety of functional levels, notably substations. The majority of these components consist of distribution substations operating at lower voltages while a small fraction are transmission substations. There is an associated geographical area that encompasses customers who are served, defined as the service area. Analysis of substation service areas is greatly complicated by several factors: distribution networks are often highly interconnected which allows a multitude of possible switching operations; also, utilities dynamically alter the network topology in order to respond to emergency events. As a result, the service area for amore » substation can change radically. A utility will generally attempt to minimize the number of customers outaged by switching effected loads to alternate substations. In this manner, all or a portion of a disabled substation's load may be served by one or more adjacent substations. This paper describes a suite of analytical tools developed at Los Alamos National Laboratory (LANL), which address the problem of determining how a utility might respond to such emergency events. The estimated outage areas derived using the tools are overlaid onto other geographical and electrical layers in a geographic information system (GIS) software application. The effects of a power outage on a population, other infrastructures, or other physical features, can be inferred by the proximity of these features to the estimated outage area.« less

30 CFR 77.501 - Electric distribution circuits and equipment; repair.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric distribution circuits and equipment... OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.501 Electric distribution circuits and equipment; repair. No electrical work shall be performed on electric distribution circuits or equipment...

Statistical theory and applications of lock-in carrierographic image pixel brightness dependence on multi-crystalline Si solar cell efficiency and photovoltage

NASA Astrophysics Data System (ADS)

Mandelis, Andreas; Zhang, Yu; Melnikov, Alexander

2012-09-01

A solar cell lock-in carrierographic image generation theory based on the concept of non-equilibrium radiation chemical potential was developed. An optoelectronic diode expression was derived linking the emitted radiative recombination photon flux (current density), the solar conversion efficiency, and the external load resistance via the closed- and/or open-circuit photovoltage. The expression was shown to be of a structure similar to the conventional electrical photovoltaic I-V equation, thereby allowing the carrierographic image to be used in a quantitative statistical pixel brightness distribution analysis with outcome being the non-contacting measurement of mean values of these important parameters averaged over the entire illuminated solar cell surface. This is the optoelectronic equivalent of the electrical (contacting) measurement method using an external resistor circuit and the outputs of the solar cell electrode grid, the latter acting as an averaging distribution network over the surface. The statistical theory was confirmed using multi-crystalline Si solar cells.

Stocks, Flows, and Distribution of Critical Metals in Embedded Electronics in Passenger Vehicles.

PubMed

Restrepo, Eliette; Løvik, Amund N; Wäger, Patrick; Widmer, Rolf; Lonka, Radek; Müller, Daniel B

2017-02-07

One of the major applications of critical metals (CMs) is in electrical and electronic equipment (EEE), which is increasingly embedded in other products, notably passenger vehicles. However, recycling strategies for future CM quantities in end-of-life vehicles (ELVs) are poorly understood, mainly due to a limited understating of the complexity of automotive embedded EEE. We introduce a harmonization of the network structure of automotive electronics that enables a comprehensive quantification of CMs in all embedded EEE in a vehicle. This network is combined with a material flow analysis along the vehicle lifecycle in Switzerland to quantify the stocks and flows of Ag, Au, Pd, Ru, Dy, La, Nd, and Co in automotive embedded EEE. In vehicles in use, we calculated 5 -2 +3 t precious metals in controllers embedded in all vehicle types and 220 -60 +90 t rare earth elements (REE); found mainly in five electric motors: alternator, starter, radiator-fan and electronic power steering motor embedded in conventional passenger vehicles and drive motor/generator embedded in hybrid and electric vehicles. Dismantling these devices before ELV shredding, as well as postshredder treatment of automobile shredder residue may increase the recovery of CMs from ELVs. Environmental and economic implications of such recycling strategies must be considered.

Thermal energy storage to minimize cost and improve efficiency of a polygeneration district energy system in a real-time electricity market

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powell, Kody M.; Kim, Jong Suk; Cole, Wesley J.

2016-10-01

District energy systems can produce low-cost utilities for large energy networks, but can also be a resource for the electric grid by their ability to ramp production or to store thermal energy by responding to real-time market signals. In this work, dynamic optimization exploits the flexibility of thermal energy storage by determining optimal times to store and extract excess energy. This concept is applied to a polygeneration distributed energy system with combined heat and power, district heating, district cooling, and chilled water thermal energy storage. The system is a university campus responsible for meeting the energy needs of tens ofmore » thousands of people. The objective for the dynamic optimization problem is to minimize cost over a 24-h period while meeting multiple loads in real time. The paper presents a novel algorithm to solve this dynamic optimization problem with energy storage by decomposing the problem into multiple static mixed-integer nonlinear programming (MINLP) problems. Another innovative feature of this work is the study of a large, complex energy network which includes the interrelations of a wide variety of energy technologies. Results indicate that a cost savings of 16.5% is realized when the system can participate in the wholesale electricity market.« less

Continuous and reversible tuning of the disorder-driven superconductor–insulator transition in bilayer graphene

PubMed Central

Lee, Gil-Ho; Jeong, Dongchan; Park, Kee-Su; Meir, Yigal; Cha, Min-Chul; Lee, Hu-Jong

2015-01-01

The influence of static disorder on a quantum phase transition (QPT) is a fundamental issue in condensed matter physics. As a prototypical example of a disorder-tuned QPT, the superconductor–insulator transition (SIT) has been investigated intensively over the past three decades, but as yet without a general consensus on its nature. A key element is good control of disorder. Here, we present an experimental study of the SIT based on precise in-situ tuning of disorder in dual-gated bilayer graphene proximity-coupled to two superconducting electrodes through electrical and reversible control of the band gap and the charge carrier density. In the presence of a static disorder potential, Andreev-paired carriers formed close to the Fermi level in bilayer graphene constitute a randomly distributed network of proximity-induced superconducting puddles. The landscape of the network was easily tuned by electrical gating to induce percolative clusters at the onset of superconductivity. This is evidenced by scaling behavior consistent with the classical percolation in transport measurements. At lower temperatures, the solely electrical tuning of the disorder-induced landscape enables us to observe, for the first time, a crossover from classical to quantum percolation in a single device, which elucidates how thermal dephasing engages in separating the two regimes. PMID:26310774

Continuous and reversible tuning of the disorder-driven superconductor-insulator transition in bilayer graphene.

PubMed

Lee, Gil-Ho; Jeong, Dongchan; Park, Kee-Su; Meir, Yigal; Cha, Min-Chul; Lee, Hu-Jong

2015-08-27

The influence of static disorder on a quantum phase transition (QPT) is a fundamental issue in condensed matter physics. As a prototypical example of a disorder-tuned QPT, the superconductor-insulator transition (SIT) has been investigated intensively over the past three decades, but as yet without a general consensus on its nature. A key element is good control of disorder. Here, we present an experimental study of the SIT based on precise in-situ tuning of disorder in dual-gated bilayer graphene proximity-coupled to two superconducting electrodes through electrical and reversible control of the band gap and the charge carrier density. In the presence of a static disorder potential, Andreev-paired carriers formed close to the Fermi level in bilayer graphene constitute a randomly distributed network of proximity-induced superconducting puddles. The landscape of the network was easily tuned by electrical gating to induce percolative clusters at the onset of superconductivity. This is evidenced by scaling behavior consistent with the classical percolation in transport measurements. At lower temperatures, the solely electrical tuning of the disorder-induced landscape enables us to observe, for the first time, a crossover from classical to quantum percolation in a single device, which elucidates how thermal dephasing engages in separating the two regimes.

Electrically activated artificial muscles made with liquid crystal elastomers

NASA Astrophysics Data System (ADS)

Shahinpoor, Mohsen

2000-06-01

Composites of monodomain nematic liquid crystal elastomers and a conducting material distributed within their network are shown to exhibit large deformations, i.e. contraction, expansion, bending with strains of over 200% and appreciable force, by Joule heating through electrical activation. The electrical activation of the conducting material induces a rapid Joule heating in the sample leading to a nematic to isotropic phase transition where the elastomer of dimensions 32 mm x 7 mm x 0.4 mm contracted in less than a second. The cooling process, isotropic to nematic transition where the elastomer expands back to its original length, was slow and took 8 seconds. The material studied here is a highly novel liquid crystalline co-elastomer, invented and developed by Heino Finkelmann and co-workers at Albert-Ludwigs-Universitaet in Freiburg, Germany. The material is such that in which the mesogenic units are in both the side chains and the main chains of the elastomer. This co-elastomer was then mechanically loaded to induce a uniaxial network anisotropy before the cross-linking reaction was completed. These samples were then made into a composite with a conducting material such as dispersed silver particles or graphite fibers. The final samples was capable of undergoing more than 200% reversible strain in a few seconds.

An integrated multi-electrode-optrode array for in vitro optogenetics

PubMed Central

Welkenhuysen, Marleen; Hoffman, Luis; Luo, Zhengxiang; De Proft, Anabel; Van den Haute, Chris; Baekelandt, Veerle; Debyser, Zeger; Gielen, Georges; Puers, Robert; Braeken, Dries

2016-01-01

Modulation of a group of cells or tissue needs to be very precise in order to exercise effective control over the cell population under investigation. Optogenetic tools have already demonstrated to be of great value in the study of neuronal circuits and in neuromodulation. Ideally, they should permit very accurate resolution, preferably down to the single cell level. Further, to address a spatially distributed sample, independently addressable multiple optical outputs should be present. In current techniques, at least one of these requirements is not fulfilled. In addition to this, it is interesting to directly monitor feedback of the modulation by electrical registration of the activity of the stimulated cells. Here, we present the fabrication and characterization of a fully integrated silicon-based multi-electrode-optrode array (MEOA) for in vitro optogenetics. We demonstrate that this device allows for artifact-free electrical recording. Moreover, the MEOA was used to reliably elicit spiking activity from ChR2-transduced neurons. Thanks to the single cell resolution stimulation capability, we could determine spatial and temporal activation patterns and spike latencies of the neuronal network. This integrated approach to multi-site combined optical stimulation and electrical recording significantly advances today’s tool set for neuroscientists in their search to unravel neuronal network dynamics. PMID:26832455

Promoting the Market for Plug-in Hybrid and Battery Electric Vehicles: Role of Recharge Availability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Zhenhong; Greene, David L

Much recent attention has been drawn to providing adequate recharge availability as a means to promote the battery electric vehicle (BEV) and plug-in hybrid electric vehicle (PHEV) market. The possible role of improved recharge availability in developing the BEV-PHEV market and the priorities that different charging options should receive from the government require better understanding. This study reviews the charging issue and conceptualizes it into three interactions between the charge network and the travel network. With travel data from 3,755 drivers in the National Household Travel Survey, this paper estimates the distribution among U.S. consumers of (a) PHEV fuel-saving benefitsmore » by different recharge availability improvements, (b) range anxiety by different BEV ranges, and (c) willingness to pay for workplace and public charging in addition to home recharging. With the Oak Ridge National Laboratory MA3T model, the impact of three recharge improvements is quantified by the resulting increase in BEV-PHEV sales. Compared with workplace and public recharging improvements, home recharging improvement appears to have a greater impact on BEV-PHEV sales. The impact of improved recharging availability is shown to be amplified by a faster reduction in battery cost.« less

An addressable conducting network for autonomic structural health management of composite structures

NASA Astrophysics Data System (ADS)

Takahashi, Kosuke; Park, Jong Se; Hahn, H. Thomas

2010-10-01

The electrical resistance change method (ERCM) has long been an area of interest as an in-service health monitoring system. To apply the ERCM to existing structures, a new concept, the addressable conducting network (ACN), is proposed for autonomic structural health management of graphite/polymer composites. The ACN consists of two sets of conducting lines normal to each other, where one set resides on the top surface of the laminate and the other on the bottom surface. Damage can be detected by monitoring the resistance change 'through the laminate thickness' between two lines. By using a thermally mendable polymer as the matrix, the same conducting lines can be used to supply the electric current needed for resistive heating, thereby allowing the detected damage to be healed. As shown experimentally, the electrical resistance change method using an ACN distinguishes between laminates made of properly and improperly cured prepreg as well as revealing damage generated during three-point bending tests. Finite element analysis was performed to examine the feasibility of the ACN and indicated that the damage can be easily located from the spatial distribution of resistance changes and that the damaged area can be locally heated by supplying a large amount of current to selected conducting lines.

CO2 Emissions Embodied in Interprovincial Electricity Transmissions in China.

PubMed

Qu, Shen; Liang, Sai; Xu, Ming

2017-09-19

Existing studies on the evaluation of CO 2 emissions due to electricity consumption in China are inaccurate and incomplete. This study uses a network approach to calculate CO 2 emissions of purchased electricity in Chinese provinces. The CO 2 emission factors of purchased electricity range from 265 g/kWh in Sichuan to 947 g/kWh in Inner Mongolia. We find that emission factors of purchased electricity in many provinces are quite different from the emission factors of electricity generation. This indicates the importance of the network approach in accurately reflecting embodied emissions. We also observe substantial variations of emissions factors of purchased electricity within subnational grids: the provincial emission factors deviate from the corresponding subnational-grid averages from -58% to 44%. This implies that using subnational-grid averages as required by Chinese government agencies can be quite inaccurate for reporting indirect CO 2 emissions of enterprises' purchased electricity. The network approach can improve the accuracy of the quantification of embodied emissions in purchased electricity and emission flows embodied in electricity transmission.

Research Electrical Distribution Bus | Energy Systems Integration Facility

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| NREL Research Electrical Distribution Bus Research Electrical Distribution Bus The research electrical distribution bus (REDB) is the heart of the Energy Systems Integration Facility electrical system throughout the laboratories. Photo of a technician performing maintenance on the Research Electrical

Technical and Economic Assessment of the Implementation of Measures for Reducing Energy Losses in Distribution Systems

NASA Astrophysics Data System (ADS)

Aguila, Alexander; Wilson, Jorge

2017-07-01

This paper develops a methodology to assess a group of measures of electrical improvements in distribution systems, starting from the complementation of technical and economic criteria. In order to solve the problem of energy losses in distribution systems, technical and economic analysis was performed based on a mathematical model to establish a direct relationship between the energy saved by way of minimized losses and the costs of implementing the proposed measures. This paper aims at analysing the feasibility of reducing energy losses in distribution systems, by changing existing network conductors by larger crosssection conductors and distribution voltage change at higher levels. The impact of this methodology provides a highly efficient mathematical tool for analysing the feasibility of implementing improvement projects based on their costs which is a very useful tool for the distribution companies that will serve as a starting point to the analysis for this type of projects in distribution systems.

Interconnecting PV on New York City's Secondary Network Distribution System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, K; Coddington, M; Burman, K

2009-11-01

The U.S. Department of Energy (DOE) has teamed with cities across the country through the Solar America Cities (SAC) partnership program to help reduce barriers and accelerate implementation of solar energy. The New York City SAC team is a partnership between the City University of New York (CUNY), the New York City Mayor s Office of Long-term Planning and Sustainability, and the New York City Economic Development Corporation (NYCEDC).The New York City SAC team is working with DOE s National Renewable Energy Laboratory (NREL) and Con Edison, the local utility, to develop a roadmap for photovoltaic (PV) installations in themore » five boroughs. The city set a goal to increase its installed PV capacity from1.1 MW in 2005 to 8.1 MW by 2015 (the maximum allowed in 2005). A key barrier to reaching this goal, however, is the complexity of the interconnection process with the local utility. Unique challenges are associated with connecting distributed PV systems to secondary network distribution systems (simplified to networks in this report). Although most areas of the country use simpler radial distribution systems to distribute electricity, larger metropolitan areas like New York City typically use networks to increase reliability in large load centers. Unlike the radial distribution system, where each customer receives power through a single line, a network uses a grid of interconnected lines to deliver power to each customer through several parallel circuits and sources. This redundancy improves reliability, but it also requires more complicated coordination and protection schemes that can be disrupted by energy exported from distributed PV systems. Currently, Con Edison studies each potential PV system in New York City to evaluate the system s impact on the network, but this is time consuming for utility engineers and may delay the customer s project or add cost for larger installations. City leaders would like to streamline this process to facilitate faster, simpler, and less expensive distributed PV system interconnections. To assess ways to improve the interconnection process, NREL conducted a four-part study with support from DOE. The NREL team then compiled the final reports from each study into this report. In Section 1PV Deployment Analysis for New York City we analyze the technical potential for rooftop PV systems in the city. This analysis evaluates potential PV power production in ten Con Edison networks of various locations and building densities (ranging from high density apartments to lower density single family homes). Next, we compare the potential power production to network loads to determine where and when PV generation is most likely to exceed network load and disrupt network protection schemes. The results of this analysis may assist Con Edison in evaluating future PV interconnection applications and in planning future network protection system upgrades. This analysis may also assist other utilities interconnecting PV systems to networks by defining a method for assessing the technical potential of PV in the network and its impact on network loads. Section 2. A Briefing for Policy Makers on Connecting PV to a Network Grid presents an overview intended for nontechnical stakeholders. This section describes the issues associated with interconnecting PV systems to networks, along with possible solutions. Section 3. Technical Review of Concerns and Solutions to PV Interconnection in New York City summarizes common concerns of utility engineers and network experts about interconnecting PV systems to secondary networks. This section also contains detailed descriptions of nine solutions, including advantages and disadvantages, potential impacts, and road maps for deployment. Section 4. Utility Application Process Reviewlooks at utility interconnection application processes across the country and identifies administrative best practices for efficient PV interconnection.« less

Maui Smart Grid Demonstration Project Managing Distribution System Resources for Improved Service Quality and Reliability, Transmission Congestion Relief, and Grid Support Functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

none,

2014-09-30

The Maui Smart Grid Project (MSGP) is under the leadership of the Hawaii Natural Energy Institute (HNEI) of the University of Hawaii at Manoa. The project team includes Maui Electric Company, Ltd. (MECO), Hawaiian Electric Company, Inc. (HECO), Sentech (a division of SRA International, Inc.), Silver Spring Networks (SSN), Alstom Grid, Maui Economic Development Board (MEDB), University of Hawaii-Maui College (UHMC), and the County of Maui. MSGP was supported by the U.S. Department of Energy (DOE) under Cooperative Agreement Number DE-FC26-08NT02871, with approximately 50% co-funding supplied by MECO. The project was designed to develop and demonstrate an integrated monitoring, communications,more » database, applications, and decision support solution that aggregates renewable energy (RE), other distributed generation (DG), energy storage, and demand response technologies in a distribution system to achieve both distribution and transmission-level benefits. The application of these new technologies and procedures will increase MECO’s visibility into system conditions, with the expected benefits of enabling more renewable energy resources to be integrated into the grid, improving service quality, increasing overall reliability of the power system, and ultimately reducing costs to both MECO and its customers.« less

Diversity modelling for electrical power system simulation

NASA Astrophysics Data System (ADS)

Sharip, R. M.; Abu Zarim, M. A. U. A.

2013-12-01

This paper considers diversity of generation and demand profiles against the different future energy scenarios and evaluates these on a technical basis. Compared to previous studies, this research applied a forecasting concept based on possible growth rates from publically electrical distribution scenarios concerning the UK. These scenarios were created by different bodies considering aspects such as environment, policy, regulation, economic and technical. In line with these scenarios, forecasting is on a long term timescale (up to every ten years from 2020 until 2050) in order to create a possible output of generation mix and demand profiles to be used as an appropriate boundary condition for the network simulation. The network considered is a segment of rural LV populated with a mixture of different housing types. The profiles for the 'future' energy and demand have been successfully modelled by applying a forecasting method. The network results under these profiles shows for the cases studied that even though the value of the power produced from each Micro-generation is often in line with the demand requirements of an individual dwelling there will be no problems arising from high penetration of Micro-generation and demand side management for each dwellings considered. The results obtained highlight the technical issues/changes for energy delivery and management to rural customers under the future energy scenarios.

Sponge-Templated Macroporous Graphene Network for Piezoelectric ZnO Nanogenerator.

PubMed

Li, Xinda; Chen, Yi; Kumar, Amit; Mahmoud, Ahmed; Nychka, John A; Chung, Hyun-Joong

2015-09-23

We report a simple approach to fabricate zinc oxide (ZnO) nanowire based electricity generators on three-dimensional (3D) graphene networks by utilizing a commercial polyurethane (PU) sponge as a structural template. Here, a 3D network of graphene oxide is deposited from solution on the template and then is chemically reduced. Following steps of ZnO nanowire growth, polydimethylsiloxane (PDMS) backfilling and electrode lamination completes the fabrication processes. When compared to conventional generators with 2D planar geometry, the sponge template provides a 3D structure that has a potential to increase power density per unit area. The modified one-pot ZnO synthesis method allows the whole process to be inexpensive and environmentally benign. The nanogenerator yields an open circuit voltage of ∼0.5 V and short circuit current density of ∼2 μA/cm(2), while the output was found to be consistent after ∼3000 cycles. Finite element analysis of stress distribution showed that external stress is concentrated to deform ZnO nanowires by orders of magnitude compared to surrounding PU and PDMS, in agreement with our experiment. It is shown that the backfilled PDMS plays a crucial role for the stress concentration, which leads to an efficient electricity generation.

Endogenous Cortical Oscillations Constrain Neuromodulation by Weak Electric Fields

PubMed Central

Schmidt, Stephen L.; Iyengar, Apoorva K.; Foulser, A. Alban; Boyle, Michael R.; Fröhlich, Flavio

2014-01-01

Background Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation modality that may modulate cognition by enhancing endogenous neocortical oscillations with the application of sine-wave electric fields. Yet, the role of endogenous network activity in enabling and shaping the effects of tACS has remained unclear. Objective We combined optogenetic stimulation and multichannel slice electrophysiology to elucidate how the effect of weak sine-wave electric field depends on the ongoing cortical oscillatory activity. We hypothesized that the structure of the response to stimulation depended on matching the stimulation frequency to the endogenous cortical oscillation. Methods We studied the effect of weak sine-wave electric fields on oscillatory activity in mouse neocortical slices. Optogenetic control of the network activity enabled the generation of in vivo like cortical oscillations for studying the temporal relationship between network activity and sine-wave electric field stimulation. Results Weak electric fields enhanced endogenous oscillations but failed to induce a frequency shift of the ongoing oscillation for stimulation frequencies that were not matched to the endogenous oscillation. This constraint on the effect of electric field stimulation imposed by endogenous network dynamics was limited to the case of weak electric fields targeting in vivo-like network dynamics. Together, these results suggest that the key mechanism of tACS may be enhancing but not overriding of intrinsic network dynamics. Conclusion Our results contribute to understanding the inconsistent tACS results from human studies and propose that stimulation precisely adjusted in frequency to the endogenous oscillations is key to rational design of non-invasive brain stimulation paradigms. PMID:25129402

Metropolitan all-pass and inter-city quantum communication network.

PubMed

Chen, Teng-Yun; Wang, Jian; Liang, Hao; Liu, Wei-Yue; Liu, Yang; Jiang, Xiao; Wang, Yuan; Wan, Xu; Cai, Wei-Qi; Ju, Lei; Chen, Luo-Kan; Wang, Liu-Jun; Gao, Yuan; Chen, Kai; Peng, Cheng-Zhi; Chen, Zeng-Bing; Pan, Jian-Wei

2010-12-20

We have demonstrated a metropolitan all-pass quantum communication network in field fiber for four nodes. Any two nodes of them can be connected in the network to perform quantum key distribution (QKD). An optical switching module is presented that enables arbitrary 2-connectivity among output ports. Integrated QKD terminals are worked out, which can operate either as a transmitter, a receiver, or even both at the same time. Furthermore, an additional link in another city of 60 km fiber (up to 130 km) is seamless integrated into this network based on a trusted relay architecture. On all the links, we have implemented protocol of decoy state scheme. All of necessary electrical hardware, synchronization, feedback control, network software, execution of QKD protocols are made by tailored designing, which allow a completely automatical and stable running. Our system has been put into operation in Hefei in August 2009, and publicly demonstrated during an evaluation conference on quantum network organized by the Chinese Academy of Sciences on August 29, 2009. Real-time voice telephone with one-time pad encoding between any two of the five nodes (four all-pass nodes plus one additional node through relay) is successfully established in the network within 60 km.

A Comprehensive WSN-Based Approach to Efficiently Manage a Smart Grid

PubMed Central

Martinez-Sandoval, Ruben; Garcia-Sanchez, Antonio-Javier; Garcia-Sanchez, Felipe; Garcia-Haro, Joan; Flynn, David

2014-01-01

The Smart Grid (SG) is conceived as the evolution of the current electrical grid representing a big leap in terms of efficiency, reliability and flexibility compared to today's electrical network. To achieve this goal, the Wireless Sensor Networks (WSNs) are considered by the scientific/engineering community to be one of the most suitable technologies to apply SG technology to due to their low-cost, collaborative and long-standing nature. However, the SG has posed significant challenges to utility operators—mainly very harsh radio propagation conditions and the lack of appropriate systems to empower WSN devices—making most of the commercial widespread solutions inadequate. In this context, and as a main contribution, we have designed a comprehensive ad-hoc WSN-based solution for the Smart Grid (SENSED-SG) that focuses on specific implementations of the MAC, the network and the application layers to attain maximum performance and to successfully deal with any arising hurdles. Our approach has been exhaustively evaluated by computer simulations and mathematical analysis, as well as validation within real test-beds deployed in controlled environments. In particular, these test-beds cover two of the main scenarios found in a SG; on one hand, an indoor electrical substation environment, implemented in a High Voltage AC/DC laboratory, and, on the other hand, an outdoor case, deployed in the Transmission and Distribution segment of a power grid. The results obtained show that SENSED-SG performs better and is more suitable for the Smart Grid than the popular ZigBee WSN approach. PMID:25310468

Stability analysis of spacecraft power systems

NASA Technical Reports Server (NTRS)

Halpin, S. M.; Grigsby, L. L.; Sheble, G. B.; Nelms, R. M.

1990-01-01

The problems in applying standard electric utility models, analyses, and algorithms to the study of the stability of spacecraft power conditioning and distribution systems are discussed. Both single-phase and three-phase systems are considered. Of particular concern are the load and generator models that are used in terrestrial power system studies, as well as the standard assumptions of load and topological balance that lead to the use of the positive sequence network. The standard assumptions regarding relative speeds of subsystem dynamic responses that are made in the classical transient stability algorithm, which forms the backbone of utility-based studies, are examined. The applicability of these assumptions to a spacecraft power system stability study is discussed in detail. In addition to the classical indirect method, the applicability of Liapunov's direct methods to the stability determination of spacecraft power systems is discussed. It is pointed out that while the proposed method uses a solution process similar to the classical algorithm, the models used for the sources, loads, and networks are, in general, more accurate. Some preliminary results are given for a linear-graph, state-variable-based modeling approach to the study of the stability of space-based power distribution networks.

Using peer-to-peer energy-trading platforms to incentivize prosumers to form federated power plants

NASA Astrophysics Data System (ADS)

Morstyn, Thomas; Farrell, Niall; Darby, Sarah J.; McCulloch, Malcolm D.

2018-02-01

Power networks are undergoing a fundamental transition, with traditionally passive consumers becoming `prosumers' — proactive consumers with distributed energy resources, actively managing their consumption, production and storage of energy. A key question that remains unresolved is: how can we incentivize coordination between vast numbers of distributed energy resources, each with different owners and characteristics? Virtual power plants and peer-to-peer (P2P) energy trading offer different sources of value to prosumers and the power network, and have been proposed as different potential structures for future prosumer electricity markets. In this Perspective, we argue they can be combined to capture the benefits of both. We thus propose the concept of the federated power plant, a virtual power plant formed through P2P transactions between self-organizing prosumers. This addresses social, institutional and economic issues faced by top-down strategies for coordinating virtual power plants, while unlocking additional value for P2P energy trading.

Research on the effects of wind power grid to the distribution network of Henan province

NASA Astrophysics Data System (ADS)

Liu, Yunfeng; Zhang, Jian

2018-04-01

With the draining of traditional energy, all parts of nation implement policies to develop new energy to generate electricity under the favorable national policy. The wind has no pollution, Renewable and other advantages. It has become the most popular energy among the new energy power generation. The development of wind power in Henan province started relatively late, but the speed of the development is fast. The wind power of Henan province has broad development prospects. Wind power has the characteristics of volatility and randomness. The wind power access to power grids will cause much influence on the power stability and the power quality of distribution network, and some areas have appeared abandon the wind phenomenon. So the study of wind power access to power grids and find out improvement measures is very urgent. Energy storage has the properties of the space transfer energy can stabilize the operation of power grid and improve the power quality.

Reactive power optimization strategy considering analytical impedance ratio

NASA Astrophysics Data System (ADS)

Wu, Zhongchao; Shen, Weibing; Liu, Jinming; Guo, Maoran; Zhang, Shoulin; Xu, Keqiang; Wang, Wanjun; Sui, Jinlong

2017-05-01

In this paper, considering the traditional reactive power optimization cannot realize the continuous voltage adjustment and voltage stability, a dynamic reactive power optimization strategy is proposed in order to achieve both the minimization of network loss and high voltage stability with wind power. Due to the fact that wind power generation is fluctuant and uncertain, electrical equipments such as transformers and shunt capacitors may be operated frequently in order to achieve minimization of network loss, which affect the lives of these devices. In order to solve this problem, this paper introduces the derivation process of analytical impedance ratio based on Thevenin equivalent. Thus, the multiple objective function is proposed to minimize the network loss and analytical impedance ratio. Finally, taking the improved IEEE 33-bus distribution system as example, the result shows that the movement of voltage control equipment has been reduced and network loss increment is controlled at the same time, which proves the applicable value of this strategy.

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

DOEpatents

Chassin, David P [Pasco, WA; Donnelly, Matthew K [Kennewick, WA; Dagle, Jeffery E [Richland, WA

2011-12-06

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

DOEpatents

Chassin, David P.; Donnelly, Matthew K.; Dagle, Jeffery E.

2006-12-12

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

Synchronization properties of networks of electrically coupled neurons in the presence of noise and heterogeneities.

PubMed

Ostojic, Srdjan; Brunel, Nicolas; Hakim, Vincent

2009-06-01

We investigate how synchrony can be generated or induced in networks of electrically coupled integrate-and-fire neurons subject to noisy and heterogeneous inputs. Using analytical tools, we find that in a network under constant external inputs, synchrony can appear via a Hopf bifurcation from the asynchronous state to an oscillatory state. In a homogeneous net work, in the oscillatory state all neurons fire in synchrony, while in a heterogeneous network synchrony is looser, many neurons skipping cycles of the oscillation. If the transmission of action potentials via the electrical synapses is effectively excitatory, the Hopf bifurcation is supercritical, while effectively inhibitory transmission due to pronounced hyperpolarization leads to a subcritical bifurcation. In the latter case, the network exhibits bistability between an asynchronous state and an oscillatory state where all the neurons fire in synchrony. Finally we show that for time-varying external inputs, electrical coupling enhances the synchronization in an asynchronous network via a resonance at the firing-rate frequency.

Computational model of electrically coupled, intrinsically distinct pacemaker neurons.

PubMed

Soto-Treviño, Cristina; Rabbah, Pascale; Marder, Eve; Nadim, Farzan

2005-07-01

Electrical coupling between neurons with similar properties is often studied. Nonetheless, the role of electrical coupling between neurons with widely different intrinsic properties also occurs, but is less well understood. Inspired by the pacemaker group of the crustacean pyloric network, we developed a multicompartment, conductance-based model of a small network of intrinsically distinct, electrically coupled neurons. In the pyloric network, a small intrinsically bursting neuron, through gap junctions, drives 2 larger, tonically spiking neurons to reliably burst in-phase with it. Each model neuron has 2 compartments, one responsible for spike generation and the other for producing a slow, large-amplitude oscillation. We illustrate how these compartments interact and determine the dynamics of the model neurons. Our model captures the dynamic oscillation range measured from the isolated and coupled biological neurons. At the network level, we explore the range of coupling strengths for which synchronous bursting oscillations are possible. The spatial segregation of ionic currents significantly enhances the ability of the 2 neurons to burst synchronously, and the oscillation range of the model pacemaker network depends not only on the strength of the electrical synapse but also on the identity of the neuron receiving inputs. We also compare the activity of the electrically coupled, distinct neurons with that of a network of coupled identical bursting neurons. For small to moderate coupling strengths, the network of identical elements, when receiving asymmetrical inputs, can have a smaller dynamic range of oscillation than that of its constituent neurons in isolation.

Optimal Operation System of the Integrated District Heating System with Multiple Regional Branches

NASA Astrophysics Data System (ADS)

Kim, Ui Sik; Park, Tae Chang; Kim, Lae-Hyun; Yeo, Yeong Koo

This paper presents an optimal production and distribution management for structural and operational optimization of the integrated district heating system (DHS) with multiple regional branches. A DHS consists of energy suppliers and consumers, district heating pipelines network and heat storage facilities in the covered region. In the optimal management system, production of heat and electric power, regional heat demand, electric power bidding and sales, transport and storage of heat at each regional DHS are taken into account. The optimal management system is formulated as a mixed integer linear programming (MILP) where the objectives is to minimize the overall cost of the integrated DHS while satisfying the operation constraints of heat units and networks as well as fulfilling heating demands from consumers. Piecewise linear formulation of the production cost function and stairwise formulation of the start-up cost function are used to compute nonlinear cost function approximately. Evaluation of the total overall cost is based on weekly operations at each district heat branches. Numerical simulations show the increase of energy efficiency due to the introduction of the present optimal management system.

Gross domestic product estimation based on electricity utilization by artificial neural network

NASA Astrophysics Data System (ADS)

Stevanović, Mirjana; Vujičić, Slađana; Gajić, Aleksandar M.

2018-01-01

The main goal of the paper was to estimate gross domestic product (GDP) based on electricity estimation by artificial neural network (ANN). The electricity utilization was analyzed based on different sources like renewable, coal and nuclear sources. The ANN network was trained with two training algorithms namely extreme learning method and back-propagation algorithm in order to produce the best prediction results of the GDP. According to the results it can be concluded that the ANN model with extreme learning method could produce the acceptable prediction of the GDP based on the electricity utilization.

On the watch for geomagnetic storms

USGS Publications Warehouse

Green, Arthur W.; Brown, William M.

1997-01-01

Geomagnetic storms, induced by solar activity, pose significant hazards to satellites, electrical power distribution systems, radio communications, navigation, and geophysical surveys. Strong storms can expose astronauts and crews of high-flying aircraft to dangerous levels of radiation. Economic losses from recent geomagnetic storms have run into hundreds of millions of dollars. With the U.S. Geological Survey (USGS) as the lead agency, an international network of geomagnetic observatories monitors the onset of solar-induced storms and gives warnings that help diminish losses to military and commercial operations and facilities.

A Framework for Organizing Current and Future Electric Utility Regulatory and Business Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Satchwell, Andrew; Cappers, Peter; Schwartz, Lisa

In this report, we will present a descriptive and organizational framework for incremental and fundamental changes to regulatory and utility business models in the context of clean energy public policy goals. We will also discuss the regulated utility's role in providing value-added services that relate to distributed energy resources, identify the "openness" of customer information and utility networks necessary to facilitate change, and discuss the relative risks, and the shifting of risks, for utilities and customers.

Theoretical study of a thermo-acousto-electric generator equipped with an electroacoustic feedback loop

NASA Astrophysics Data System (ADS)

Olivier, Come; Penelet, Guillaume; Poignand, Gaelle; Lotton, Pierrick

2015-10-01

A simplified model of a Stirling-type thermoacoustic engine coupled to a resonant mechanical system is presented. The acoustic network is presented as its temperature-dependent lumped element equivalent, and the nonlinear effects involved in such engines are accounted for in a nonlinear heat equation governing the temperature distribution through the thermoacoustic core. The low-order model is sufficient to capture the behavior of the engine, both in terms of stability and dynamic behavior.

Electrical Properties of an m × n Hammock Network

NASA Astrophysics Data System (ADS)

Tan, Zhen; Tan, Zhi-Zhong; Zhou, Ling

2018-05-01

Electrical property is an important problem in the field of natural science and physics, which usually involves potential, current and resistance in the electric circuit. We investigate the electrical properties of an arbitrary hammock network, which has not been resolved before, and propose the exact potential formula of an arbitrary m × n hammock network by means of the Recursion-Transform method with current parameters (RT-I) pioneered by one of us [Z. Z. Tan, Phys. Rev. E 91 (2015) 052122], and the branch currents and equivalent resistance of the network are derived naturally. Our key technique is to setting up matrix equations and making matrix transformation, the potential formula derived is a meaningful discovery, which deduces many novel applications. The discovery of potential formula of the hammock network provides new theoretical tools and techniques for related scientific research. Supported by the Natural Science Foundation of Jiangsu Province under Grant No. BK20161278

EMMNet: sensor networking for electricity meter monitoring.

PubMed

Lin, Zhi-Ting; Zheng, Jie; Ji, Yu-Sheng; Zhao, Bao-Hua; Qu, Yu-Gui; Huang, Xu-Dong; Jiang, Xiu-Fang

2010-01-01

Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters.

EMMNet: Sensor Networking for Electricity Meter Monitoring

PubMed Central

Lin, Zhi-Ting; Zheng, Jie; Ji, Yu-Sheng; Zhao, Bao-Hua; Qu, Yu-Gui; Huang, Xu-Dong; Jiang, Xiu-Fang

2010-01-01

Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters. PMID:22163551

Recruitment of local inhibitory networks by horizontal connections in layer 2/3 of ferret visual cortex.

PubMed

Tucker, Thomas R; Katz, Lawrence C

2003-01-01

To investigate how neurons in cortical layer 2/3 integrate horizontal inputs arising from widely distributed sites, we combined intracellular recording and voltage-sensitive dye imaging to visualize the spatiotemporal dynamics of neuronal activity evoked by electrical stimulation of multiple sites in visual cortex. Individual stimuli evoked characteristic patterns of optical activity, while delivering stimuli at multiple sites generated interacting patterns in the regions of overlap. We observed that neurons in overlapping regions received convergent horizontal activation that generated nonlinear responses due to the emergence of large inhibitory potentials. The results indicate that co-activation of multiple sets of horizontal connections recruit strong inhibition from local inhibitory networks, causing marked deviations from simple linear integration.

Overexpression of cypin alters dendrite morphology, single neuron activity, and network properties via distinct mechanisms

NASA Astrophysics Data System (ADS)

Rodríguez, Ana R.; O'Neill, Kate M.; Swiatkowski, Przemyslaw; Patel, Mihir V.; Firestein, Bonnie L.

2018-02-01

Objective. This study investigates the effect that overexpression of cytosolic PSD-95 interactor (cypin), a regulator of synaptic PSD-95 protein localization and a core regulator of dendrite branching, exerts on the electrical activity of rat hippocampal neurons and networks. Approach. We cultured rat hippocampal neurons and used lipid-mediated transfection and lentiviral gene transfer to achieve high levels of cypin or cypin mutant (cypinΔPDZ PSD-95 non-binding) expression cellularly and network-wide, respectively. Main results. Our analysis revealed that although overexpression of cypin and cypinΔPDZ increase dendrite numbers and decrease spine density, cypin and cypinΔPDZ distinctly regulate neuronal activity. At the single cell level, cypin promotes decreases in bursting activity while cypinΔPDZ reduces sEPSC frequency and further decreases bursting compared to cypin. At the network level, by using the Fano factor as a measure of spike count variability, cypin overexpression results in an increase in variability of spike count, and this effect is abolished when cypin cannot bind PSD-95. This variability is also dependent on baseline activity levels and on mean spike rate over time. Finally, our spike sorting data show that overexpression of cypin results in a more complex distribution of spike waveforms and that binding to PSD-95 is essential for this complexity. Significance. Our data suggest that dendrite morphology does not play a major role in cypin action on electrical activity.

Analysis of fault-tolerant neurocontrol architectures

NASA Technical Reports Server (NTRS)

Troudet, T.; Merrill, W.

1992-01-01

The fault-tolerance of analog parallel distributed implementations of a multivariable aircraft neurocontroller is analyzed by simulating weight and neuron failures in a simplified scheme of analog processing based on the functional architecture of the ETANN chip (Electrically Trainable Artificial Neural Network). The neural information processing is found to be only partially distributed throughout the set of weights of the neurocontroller synthesized with the backpropagation algorithm. Although the degree of distribution of the neural processing, and consequently the fault-tolerance of the neurocontroller, could be enhanced using Locally Distributed Weight and Neuron Approaches, a satisfactory level of fault-tolerance could only be obtained by retraining the degrated VLSI neurocontroller. The possibility of maintaining neurocontrol performance and stability in the presence of single weight of neuron failures was demonstrated through an automated retraining procedure of the neurocontroller based on a pre-programmed choice and sequence of the training parameters.

Optical technologies for the Internet of Things era

NASA Astrophysics Data System (ADS)

Ji, Philip N.

2017-08-01

Internet of Things (IoT) is a network of interrelated physical objects that can collect and exchange data with one another through embedded electronics, software, sensors, over the Internet. It extends Internet connectivity beyond traditional networking devices to a diverse range of physical devices and everyday things that utilize embedded technologies to communicate and interact with the external environment. The IoT brings automation and efficiency improvement to everyday life, business, and society. Therefore IoT applications and market are growing rapidly. Contrary to common belief that IoT is only related to wireless technology, optical technologies actually play important roles in the growth of IoT and contribute to its advancement. Firstly, fiber optics provides the backbone for transporting large amount of data generated by IoT network in the core , metro and access networks, and in building or in the physical object. Secondly, optical switching technologies, including all-optical switching and hybrid optical-electrical switching, enable fast and high bandwidth routing in IoT data processing center. Thirdly, optical sensing and imaging delivers comprehensive information of multiple physical phenomena through monitoring various optical properties such as intensity, phase, wavelength, frequency, polarization, and spectral distribution. In particular, fiber optic sensor has the advantages of high sensitivity, low latency, and long distributed sensing range. It is also immune to electromagnetic interference, and can be implemented in harsh environment. In this paper, the architecture of IoT is described, and the optical technologies and their applications in the IoT networks are discussed with practical examples.

Network meta-analysis, electrical networks and graph theory.

PubMed

Rücker, Gerta

2012-12-01

Network meta-analysis is an active field of research in clinical biostatistics. It aims to combine information from all randomized comparisons among a set of treatments for a given medical condition. We show how graph-theoretical methods can be applied to network meta-analysis. A meta-analytic graph consists of vertices (treatments) and edges (randomized comparisons). We illustrate the correspondence between meta-analytic networks and electrical networks, where variance corresponds to resistance, treatment effects to voltage, and weighted treatment effects to current flows. Based thereon, we then show that graph-theoretical methods that have been routinely applied to electrical networks also work well in network meta-analysis. In more detail, the resulting consistent treatment effects induced in the edges can be estimated via the Moore-Penrose pseudoinverse of the Laplacian matrix. Moreover, the variances of the treatment effects are estimated in analogy to electrical effective resistances. It is shown that this method, being computationally simple, leads to the usual fixed effect model estimate when applied to pairwise meta-analysis and is consistent with published results when applied to network meta-analysis examples from the literature. Moreover, problems of heterogeneity and inconsistency, random effects modeling and including multi-armed trials are addressed. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.

Swelling characteristics of acrylic acid polyelectrolyte hydrogel in a dc electric field

NASA Astrophysics Data System (ADS)

Jabbari, Esmaiel; Tavakoli, Javad; Sarvestani, Alireza S.

2007-10-01

A novel application of environmentally sensitive polyelectrolytes is in the fabrication of BioMEMS devices as sensors and actuators. Poly(acrylic acid) (PAA) gels are anionic polyelectrolyte networks that exhibit volume expansion in aqueous physiological environments. When an electric field is applied to PAA polyelectrolyte gels, the fixed anionic polyelectrolyte charges and the requirement of electro-neutrality in the network generate an osmotic pressure, above that in the absence of the electric field, to expand the network. The objective of this research was to investigate the effect of an externally applied dc electric field on the volume expansion of the PAA polyelectrolyte gel in a simulated physiological solution of phosphate buffer saline (PBS). For swelling studies in the electric field, two platinum-coated plates, as electrodes, were wrapped in a polyethylene sheet to protect the plates from corrosion and placed vertically in a vessel filled with PBS. The plates were placed on a rail such that the distance between the two plates could be adjusted. The PAA gel was synthesized by free radical crosslinking of acrylic acid monomer with ethylene glycol dimethacrylate (EGDMA) crosslinker. Our results demonstrate that volume expansion depends on the intensity of the electric field, the PAA network density, network homogeneity, and the position of the gel in the field relative to positive/negative electrodes. Our model predictions for PAA volume expansion, based on the dilute electrolyte concentration in the gel network, is in excellent agreement with the experimental findings in the high-electric-field regime (250-300 Newton/Coulomb).

Neural network based load and price forecasting and confidence interval estimation in deregulated power markets

NASA Astrophysics Data System (ADS)

Zhang, Li

With the deregulation of the electric power market in New England, an independent system operator (ISO) has been separated from the New England Power Pool (NEPOOL). The ISO provides a regional spot market, with bids on various electricity-related products and services submitted by utilities and independent power producers. A utility can bid on the spot market and buy or sell electricity via bilateral transactions. Good estimation of market clearing prices (MCP) will help utilities and independent power producers determine bidding and transaction strategies with low risks, and this is crucial for utilities to compete in the deregulated environment. MCP prediction, however, is difficult since bidding strategies used by participants are complicated and MCP is a non-stationary process. The main objective of this research is to provide efficient short-term load and MCP forecasting and corresponding confidence interval estimation methodologies. In this research, the complexity of load and MCP with other factors is investigated, and neural networks are used to model the complex relationship between input and output. With improved learning algorithm and on-line update features for load forecasting, a neural network based load forecaster was developed, and has been in daily industry use since summer 1998 with good performance. MCP is volatile because of the complexity of market behaviors. In practice, neural network based MCP predictors usually have a cascaded structure, as several key input factors need to be estimated first. In this research, the uncertainties involved in a cascaded neural network structure for MCP prediction are analyzed, and prediction distribution under the Bayesian framework is developed. A fast algorithm to evaluate the confidence intervals by using the memoryless Quasi-Newton method is also developed. The traditional back-propagation algorithm for neural network learning needs to be improved since MCP is a non-stationary process. The extended Kalman filter (EKF) can be used as an integrated adaptive learning and confidence interval estimation algorithm for neural networks, with fast convergence and small confidence intervals. However, EKF learning is computationally expensive because it involves high dimensional matrix manipulations. A modified U-D factorization within the decoupled EKF (DEKF-UD) framework is developed in this research. The computational efficiency and numerical stability are significantly improved.

Time series prediction in the case of nonlinear loads by using ADALINE and NAR neural networks

NASA Astrophysics Data System (ADS)

Ghiormez, L.; Panoiu, M.; Panoiu, C.; Tirian, O.

2018-01-01

This paper presents a study regarding the time series prediction in the case of an electric arc furnace. The considered furnace is a three phase load and it is used to melt scrap in order to obtain liquid steel. The furnace is powered by a three-phase electrical supply and therefore has three graphite electrodes. The furnace is a nonlinear load that can influence the equipment connected to the same electrical power supply network. The nonlinearity is given by the electric arc that appears at the furnace between the graphite electrode and the scrap. Because of the disturbances caused by the electric arc furnace during the elaboration process of steel it is very useful to predict the current of the electric arc and the voltage from the measuring point in the secondary side of the furnace transformer. In order to make the predictions were used ADALINE and NAR neural networks. To train the networks and to make the predictions were used data acquired from the real technological plant.

Optically triggered high voltage switch network and method for switching a high voltage

DOEpatents

El-Sharkawi, Mohamed A.; Andexler, George; Silberkleit, Lee I.

1993-01-19

An optically triggered solid state switch and method for switching a high voltage electrical current. A plurality of solid state switches (350) are connected in series for controlling electrical current flow between a compensation capacitor (112) and ground in a reactive power compensator (50, 50') that monitors the voltage and current flowing through each of three distribution lines (52a, 52b and 52c), which are supplying three-phase power to one or more inductive loads. An optical transmitter (100) controlled by the reactive power compensation system produces light pulses that are conveyed over optical fibers (102) to a switch driver (110') that includes a plurality of series connected optical triger circuits (288). Each of the optical trigger circuits controls a pair of the solid state switches and includes a plurality of series connected resistors (294, 326, 330, and 334) that equalize or balance the potential across the plurality of trigger circuits. The trigger circuits are connected to one of the distribution lines through a trigger capacitor (340). In each switch driver, the light signals activate a phototransistor (300) so that an electrical current flows from one of the energy reservoir capacitors through a pulse transformer (306) in the trigger circuit, producing gate signals that turn on the pair of serially connected solid state switches (350).

Load allocation of power plant using multi echelon economic dispatch

NASA Astrophysics Data System (ADS)

Wahyuda, Santosa, Budi; Rusdiansyah, Ahmad

2017-11-01

In this paper, the allocation of power plant load which is usually done with a single echelon as in the load flow calculation, is expanded into a multi echelon. A plant load allocation model based on the integration of economic dispatch and multi-echelon problem is proposed. The resulting model is called as Single Objective Multi Echelon Economic Dispatch (SOME ED). This model allows the distribution of electrical power in more detail in the transmission and distribution substations along the existing network. Considering the interconnection system where the distance between the plant and the load center is usually far away, therefore the loss in this model is seen as a function of distance. The advantages of this model is its capability of allocating electrical loads properly, as well as economic dispatch information with the flexibility of electric power system as a result of using multi-echelon. In this model, the flexibility can be viewed from two sides, namely the supply and demand sides, so that the security of the power system is maintained. The model was tested on a small artificial data. The results demonstrated a good performance. It is still very open to further develop the model considering the integration with renewable energy, multi-objective with environmental issues and applied to the case with a larger scale.

Effect of Morphologic Features of Neurons on the Extracellular Electric Potential: A Simulation Study Using Cable Theory and Electro-Quasi-Static Equations.

PubMed

Bestel, R; Appali, R; van Rienen, U; Thielemann, C

2017-11-01

Microelectrode arrays serve as an indispensable tool in electro-physiological research to study the electrical activity of neural cells, enabling measurements of single cell as well as network communication analysis. Recent experimental studies have reported that the neuronal geometry has an influence on electrical signaling and extracellular recordings. However, the corresponding mechanisms are not yet fully understood and require further investigation. Allowing systematic parameter studies, computational modeling provides the opportunity to examine the underlying effects that influence extracellular potentials. In this letter, we present an in silico single cell model to analyze the effect of geometrical variability on the extracellular electric potentials. We describe finite element models of a single neuron with varying geometric complexity in three-dimensional space. The electric potential generation of the neuron is modeled using Hodgkin-Huxley equations. The signal propagation is described with electro-quasi-static equations, and results are compared with corresponding cable equation descriptions. Our results show that both the geometric dimensions and the distribution of ion channels of a neuron are critical factors that significantly influence both the amplitude and shape of extracellular potentials.

Recycling potential for low voltage and high voltage high rupturing capacity fuse links.

PubMed

Psomopoulos, Constantinos S; Barkas, Dimitrios A; Kaminaris, Stavros D; Ioannidis, George C; Karagiannopoulos, Panagiotis

2017-12-01

Low voltage and high voltage high-rupturing-capacity fuse links are used in LV and HV installations respectively, protecting mainly the LV and HV electricity distribution and transportation networks. The Waste Electrical and Electronic Equipment Directive (2002/96/EC) for "Waste of electrical and electronic equipment" is the main related legislation and as it concerns electrical and electronic equipment, it includes electric fuses. Although, the fuse links consist of recyclable materials, only small scale actions have been implemented for their recycling around Europe. This work presents the possibilities for material recovery from this specialized industrial waste for which there are only limited volume data. Furthermore, in order to present the huge possibilities and environmental benefits, it presents the potential for recycling of HRC fuses used by the Public Power Corporation of Greece, which is the major consumer for the country, but one of the smallest ones in Europe and globally, emphasizing in this way in the issue. According to the obtained results, fuse recycling could contribute to the effort for minimize the impacts on the environment through materials recovery and reduction of the wastes' volume disposed of in landfills. Copyright © 2017 Elsevier Ltd. All rights reserved.

A simulation-based efficiency comparison of AC and DC power distribution networks in commercial buildings

DOE PAGES

Gerber, Daniel L.; Vossos, Vagelis; Feng, Wei; ...

2017-06-12

Direct current (DC) power distribution has recently gained traction in buildings research due to the proliferation of on-site electricity generation and battery storage, and an increasing prevalence of internal DC loads. The research discussed in this paper uses Modelica-based simulation to compare the efficiency of DC building power distribution with an equivalent alternating current (AC) distribution. The buildings are all modeled with solar generation, battery storage, and loads that are representative of the most efficient building technology. A variety of paramet ric simulations determine how and when DC distribution proves advantageous. These simulations also validate previous studies that use simplermore » approaches and arithmetic efficiency models. This work shows that using DC distribution can be considerably more efficient: a medium sized office building using DC distribution has an expected baseline of 12% savings, but may also save up to 18%. In these results, the baseline simulation parameters are for a zero net energy (ZNE) building that can island as a microgrid. DC is most advantageous in buildings with large solar capacity, large battery capacity, and high voltage distribution.« less

A simulation-based efficiency comparison of AC and DC power distribution networks in commercial buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerber, Daniel L.; Vossos, Vagelis; Feng, Wei

Direct current (DC) power distribution has recently gained traction in buildings research due to the proliferation of on-site electricity generation and battery storage, and an increasing prevalence of internal DC loads. The research discussed in this paper uses Modelica-based simulation to compare the efficiency of DC building power distribution with an equivalent alternating current (AC) distribution. The buildings are all modeled with solar generation, battery storage, and loads that are representative of the most efficient building technology. A variety of paramet ric simulations determine how and when DC distribution proves advantageous. These simulations also validate previous studies that use simplermore » approaches and arithmetic efficiency models. This work shows that using DC distribution can be considerably more efficient: a medium sized office building using DC distribution has an expected baseline of 12% savings, but may also save up to 18%. In these results, the baseline simulation parameters are for a zero net energy (ZNE) building that can island as a microgrid. DC is most advantageous in buildings with large solar capacity, large battery capacity, and high voltage distribution.« less

Recycling and reuse of waste from electricity distribution networks as reinforcement agents in polymeric composites.

PubMed

Zimmermann, Matheus V G; Zattera, Ademir J

2013-07-01

Of the waste generated from electricity distribution networks, wooden posts treated with chromated copper arsenate (CCA) and ceramic insulators make up the majority of the materials for which no effective recycling scheme has been developed. This study aims to recycle and reuse this waste as reinforcement elements in polymer composites and hybrid composites, promoting an ecologically and economically viable alternative for the disposal of this waste. The CCA wooden posts were cut, crushed and recycled via acid leaching using 0.2 and 0.4N H2SO4 in triplicate at 70°C and then washed and dried. The ceramic insulators were fragmented in a hydraulic press and separated by particle size using a vibrating sieve. The composites were mixed in a twin-screw extruder and injected into the test specimens, which were subjected to physical, mechanical, thermal and morphological characterization. The results indicate that the acid treatment most effective for removing heavy metals in the wood utilizes 0.4NH2SO4. However, the composites made from wood treated with 0.2NH2SO4 exhibited the highest mechanical properties of the composites, whereas the use of a ceramic insulator produces composites with better thermal stability and impact strength. This study is part of the research and development project of ANEEL (Agência Nacional de Energia Elétrica) and funded by CPFL (Companhia Paulista de Força e Luz). Copyright © 2013 Elsevier Ltd. All rights reserved.

Excitement and synchronization of small-world neuronal networks with short-term synaptic plasticity.

PubMed

Han, Fang; Wiercigroch, Marian; Fang, Jian-An; Wang, Zhijie

2011-10-01

Excitement and synchronization of electrically and chemically coupled Newman-Watts (NW) small-world neuronal networks with a short-term synaptic plasticity described by a modified Oja learning rule are investigated. For each type of neuronal network, the variation properties of synaptic weights are examined first. Then the effects of the learning rate, the coupling strength and the shortcut-adding probability on excitement and synchronization of the neuronal network are studied. It is shown that the synaptic learning suppresses the over-excitement, helps synchronization for the electrically coupled network but impairs synchronization for the chemically coupled one. Both the introduction of shortcuts and the increase of the coupling strength improve synchronization and they are helpful in increasing the excitement for the chemically coupled network, but have little effect on the excitement of the electrically coupled one.

Tablet based distributed intelligent load management

DOEpatents

Lu, Yan; Zhou, Siyuan

2018-01-09

A facility is connected to an electricity utility and is responsive to Demand Response Events. A plurality of devices is each individually connected to the electricity grid via an addressable switch connected to a secure network that is enabled to be individually switched off by a server. An occupant of a room in control of the plurality of devices provides via a Human Machine Interface on a tablet a preferred order of switching off the plurality of devices in case of a Demand Response Event. A configuration file based at least partially on the preferred order and on a severity of the Demand Response Events determines which devices which of the plurality devices will be switched off. The server accesses the configuration file and switches off the devices included in the configuration file.

Heat Pipe Technology

NASA Astrophysics Data System (ADS)

1981-01-01

The heat pipe, a sealed chamber whose walls are lined with a "wick," a thin capillary network containing a working fluid in liquid form was developed for a heat distribution system for non-rotating satellites. Use of the heat pipe provides a continuous heat transfer mechanism. "Heat tubes" that improve temperature control in plastics manufacturing equipment incorporated the heat pipe technology. James M. Stewart, an independent consultant, patented the heat tubes he developed and granted a license to Kona Corporation. The Kona Nozzle for heaterless injection molding gets heat for its operation from an external source and has no internal heating bands, reducing machine maintenance and also eliminating electrical hazards associated with heater bands. The nozzles are used by Eastman Kodak, Bic Pen Corporation, Polaroid, Tupperware, Ford Motor Company, RCA, and Western Electric in the molding of their products.

Social representations of electricity network technologies: exploring processes of anchoring and objectification through the use of visual research methods.

PubMed

Devine-Wright, Hannah; Devine-Wright, Patrick

2009-06-01

The aim of this study was to explore everyday thinking about the UK electricity network, in light of government policy to increase the generation of electricity from renewable energy sources. Existing literature on public perceptions of electricity network technologies was broadened by adopting a more socially embedded conception of the construction of knowledge using the theory of social representations (SRT) to explore symbolic associations with network technologies. Drawing and association tasks were administered within nine discussion groups held in two places: a Scottish town where significant upgrades to the local transmission network were planned and an English city with no such plans. Our results illustrate the ways in which network technologies, such as high voltage (HV) pylons, are objectified in talk and drawings. These invoked positive as well as negative symbolic and affective associations, both at the level of specific pylons, and the 'National Grid' as a whole and are anchored in understanding of other networks such as mobile telecommunications. We conclude that visual methods are especially useful for exploring beliefs about technologies that are widespread, proximal to our everyday experience but nevertheless unfamiliar topics of everyday conversation.

Modeling of synchronization behavior of bursting neurons at nonlinearly coupled dynamical networks.

PubMed

Çakir, Yüksel

2016-01-01

Synchronization behaviors of bursting neurons coupled through electrical and dynamic chemical synapses are investigated. The Izhikevich model is used with random and small world network of bursting neurons. Various currents which consist of diffusive electrical and time-delayed dynamic chemical synapses are used in the simulations to investigate the influences of synaptic currents and couplings on synchronization behavior of bursting neurons. The effects of parameters, such as time delay, inhibitory synaptic strengths, and decay time on synchronization behavior are investigated. It is observed that in random networks with no delay, bursting synchrony is established with the electrical synapse alone, single spiking synchrony is observed with hybrid coupling. In small world network with no delay, periodic bursting behavior with multiple spikes is observed when only chemical and only electrical synapse exist. Single-spike and multiple-spike bursting are established with hybrid couplings. A decrease in the synchronization measure is observed with zero time delay, as the decay time is increased in random network. For synaptic delays which are above active phase period, synchronization measure increases with an increase in synaptic strength and time delay in small world network. However, in random network, it increases with only an increase in synaptic strength.

Carbon nanotube-based bioceramic grafts for electrotherapy of bone.

PubMed

Mata, D; Horovistiz, A L; Branco, I; Ferro, M; Ferreira, N M; Belmonte, M; Lopes, M A; Silva, R F; Oliveira, F J

2014-01-01

Bone complexity demands the engineering of new scaffolding solutions for its reconstructive surgery. Emerging bone grafts should offer not only mechanical support but also functional properties to explore innovative bone therapies. Following this, ceramic bone grafts of Glass/hydroxyapatite (HA) reinforced with conductive carbon nanotubes (CNTs) - CNT/Glass/HA - were prepared for bone electrotherapy purposes. Computer-aided 3D microstructural reconstructions and TEM analysis of CNT/Glass/HA composites provided details on the CNT 3D network and further correlation to their functional properties. CNTs are arranged as sub-micrometric sized ropes bridging homogenously distributed ellipsoid-shaped agglomerates. This arrangement yielded composites with a percolation threshold of pc=1.5vol.%. At 4.4vol.% of CNTs, thermal and electrical conductivities of 1.5W·m(-1)·K(-1) and 55S·m(-1), respectively, were obtained, matching relevant requisites in electrical stimulation protocols. While the former avoids bone damaging from Joule's heat generation, the latter might allow the confinement of external electrical fields through the conductive material if used for in vivo electrical stimulation. Moreover, the electrically conductive bone grafts have better mechanical properties than those of the natural cortical bone. Overall, these highly conductive materials with controlled size CNT agglomerates might accelerate bone bonding and maximize the delivery of electrical stimulation during electrotherapy practices. © 2013.

Quantum key distribution using card, base station and trusted authority

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nordholt, Jane E.; Hughes, Richard John; Newell, Raymond Thorson

Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trust authority. The keys can be used to set up secure communication, for authentication, for access control, or formore » other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.« less

Quantum key distribution using card, base station and trusted authority

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nordholt, Jane Elizabeth; Hughes, Richard John; Newell, Raymond Thorson

Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trusted authority. The keys can be used to set up secure communication, for authentication, for access control, or formore » other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.« less

Multi-focus and multi-level techniques for visualization and analysis of networks with thematic data

NASA Astrophysics Data System (ADS)

Cossalter, Michele; Mengshoel, Ole J.; Selker, Ted

2013-01-01

Information-rich data sets bring several challenges in the areas of visualization and analysis, even when associated with node-link network visualizations. This paper presents an integration of multi-focus and multi-level techniques that enable interactive, multi-step comparisons in node-link networks. We describe NetEx, a visualization tool that enables users to simultaneously explore different parts of a network and its thematic data, such as time series or conditional probability tables. NetEx, implemented as a Cytoscape plug-in, has been applied to the analysis of electrical power networks, Bayesian networks, and the Enron e-mail repository. In this paper we briefly discuss visualization and analysis of the Enron social network, but focus on data from an electrical power network. Specifically, we demonstrate how NetEx supports the analytical task of electrical power system fault diagnosis. Results from a user study with 25 subjects suggest that NetEx enables more accurate isolation of complex faults compared to an especially designed software tool.

Developing Large-Scale Bayesian Networks by Composition: Fault Diagnosis of Electrical Power Systems in Aircraft and Spacecraft

NASA Technical Reports Server (NTRS)

Mengshoel, Ole Jakob; Poll, Scott; Kurtoglu, Tolga

2009-01-01

In this paper, we investigate the use of Bayesian networks to construct large-scale diagnostic systems. In particular, we consider the development of large-scale Bayesian networks by composition. This compositional approach reflects how (often redundant) subsystems are architected to form systems such as electrical power systems. We develop high-level specifications, Bayesian networks, clique trees, and arithmetic circuits representing 24 different electrical power systems. The largest among these 24 Bayesian networks contains over 1,000 random variables. Another BN represents the real-world electrical power system ADAPT, which is representative of electrical power systems deployed in aerospace vehicles. In addition to demonstrating the scalability of the compositional approach, we briefly report on experimental results from the diagnostic competition DXC, where the ProADAPT team, using techniques discussed here, obtained the highest scores in both Tier 1 (among 9 international competitors) and Tier 2 (among 6 international competitors) of the industrial track. While we consider diagnosis of power systems specifically, we believe this work is relevant to other system health management problems, in particular in dependable systems such as aircraft and spacecraft. (See CASI ID 20100021910 for supplemental data disk.)

Nanoscale Control over the Mixing Behavior of Surface-Confined Bicomponent Supramolecular Networks Using an Oriented External Electric Field

PubMed Central

2017-01-01

Strong electric fields are known to influence the properties of molecules as well as materials. Here we show that by changing the orientation of an externally applied electric field, one can locally control the mixing behavior of two molecules physisorbed on a solid surface. Whether the starting two-component network evolves into an ordered two-dimensional (2D) cocrystal, yields an amorphous network where the two components phase separate, or shows preferential adsorption of only one component depends on the solution stoichiometry. The experiments are carried out by changing the orientation of the strong electric field that exists between the tip of a scanning tunneling microscope and a solid substrate. The structure of the two-component network typically changes from open porous at negative substrate bias to relatively compact when the polarity of the applied bias is reversed. The electric-field-induced mixing behavior is reversible, and the supramolecular system exhibits excellent stability and good response efficiency. When molecular guests are adsorbed in the porous networks, the field-induced switching behavior was found to be completely different. Plausible reasons behind the field-induced mixing behavior are discussed. PMID:29112378

46 CFR 28.855 - Electrical distribution systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Electrical distribution systems. 28.855 Section 28.855... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor...

46 CFR 28.360 - Electrical distribution systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Electrical distribution systems. 28.360 Section 28.360... Operate With More Than 16 Individuals on Board § 28.360 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor...

46 CFR 28.360 - Electrical distribution systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Electrical distribution systems. 28.360 Section 28.360... Operate With More Than 16 Individuals on Board § 28.360 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor...

46 CFR 28.360 - Electrical distribution systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Electrical distribution systems. 28.360 Section 28.360... Operate With More Than 16 Individuals on Board § 28.360 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor...

46 CFR 28.855 - Electrical distribution systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Electrical distribution systems. 28.855 Section 28.855... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor...

46 CFR 28.360 - Electrical distribution systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Electrical distribution systems. 28.360 Section 28.360... Operate With More Than 16 Individuals on Board § 28.360 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor...

46 CFR 28.855 - Electrical distribution systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Electrical distribution systems. 28.855 Section 28.855... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor...

46 CFR 28.855 - Electrical distribution systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Electrical distribution systems. 28.855 Section 28.855... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor...

Investigating the consequences of urban volcanism using a scenario approach I: Development and application of a hypothetical eruption in the Auckland Volcanic Field, New Zealand

NASA Astrophysics Data System (ADS)

Deligne, Natalia I.; Fitzgerald, Rebecca H.; Blake, Daniel M.; Davies, Alistair J.; Hayes, Josh L.; Stewart, Carol; Wilson, Grant; Wilson, Thomas M.; Castelino, Renella; Kennedy, Ben M.; Muspratt, Scott; Woods, Richard

2017-04-01

What happens when a city has a volcanic eruption within its boundaries? To explore the consequences of this rare but potentially catastrophic combination, we develop a detailed multi-hazard scenario of an Auckland Volcanic Field (AVF) eruption; the AVF underlies New Zealand's largest city, Auckland. We start with an existing AVF unrest scenario sequence and develop it through a month-long hypothetical eruption based on geologic investigations of the AVF and historic similar eruptions from around the world. We devise a credible eruption sequence and include all volcanic hazards that could occur in an AVF eruption. In consultation with Civil Defence and Emergency Management staff, we create a series of evacuation maps for before, during, and after the hypothetical eruption sequence. Our result is a versatile scenario with many possible applications, developed further in companion papers that explore eruption consequences on transportation and water networks. However, here we illustrate one application: evaluating the consequences of an eruption on electricity service provision. In a collaborative approach between scientists and electricity service providers, we evaluate the impact of the hypothetical eruption to electricity generation, transmission, and distribution infrastructure. We then evaluate how the impacted network functions, accounting for network adaptations (e.g., diverting power away from evacuated areas), site access, and restoration factors. We present a series of regional maps showing areas with full service, rolling outages, and no power as a result of the eruption. This illustrative example demonstrates how a detailed scenario can be used to further understand the ramifications of urban volcanism on local and regional populations, and highlights the importance of looking beyond damage to explore the consequences of volcanism.

Evaluating the electricity intensity of evolving water supply mixes: the case of California’s water network

NASA Astrophysics Data System (ADS)

Stokes-Draut, Jennifer; Taptich, Michael; Kavvada, Olga; Horvath, Arpad

2017-11-01

Climate change is making water supply less predictable, even unreliable, in parts of the world. Urban water providers, especially in already arid areas, will need to diversify their water resources by switching to alternative sources and negotiating trading agreements to create more resilient and interdependent networks. The increasing complexity of these networks will likely require more operational electricity. The ability to document, visualize, and analyze water-energy relationships will be critical to future water planning, especially as data needed to conduct the analyses become increasingly available. We have developed a network model and decision-support tool, WESTNet, to perform these tasks. Herein, WESTNet was used to analyze a model of California’s 2010 urban water network as well as the projected system for 2020 and 2030. Results for California’s ten hydrologic regions show that the average number of water sources per utility and total electricity consumption for supplying water will increase in spite of decreasing per-capita water consumption. Electricity intensity (kWh m-3) will increase in arid regions of the state due to shifts to alternative water sources such as indirect potable water reuse, desalination, and water transfers. In wetter, typically less populated, regions, reduced water demand for electricity-intensive supplies will decrease the electricity intensity of the water supply mix, though total electricity consumption will increase due to urban population growth. The results of this study provide a baseline for comparing current and potential innovations to California’s water system. The WESTNet tool can be applied to diverse water systems in any geographic region at a variety of scales to evaluate an array of network-dependent water-energy parameters.

Recent Trend of New Type Power Delivery System and its Demonstrative Project in Japan

NASA Astrophysics Data System (ADS)

Morozumi, Satoshi; Nara, Koichi

Recently many such distributed generating systems as co-generation, photovoltaic, wind, fuel cells etc. are introduced into power distribution system, and the power system must cope with the situation with distributed generators. Moreover, such industries as IT request reliable and high quality power to preserve their businesses, and some other electric energy based industries request less reliable but cheaper electricity. From these backgrounds, several new type power delivery systems are emerging where lots of distributed generators (DGs) can be connected and many benefits offered by DGs can be realized without affecting the existing power system. They are referred to various names. In U.S.A., Microgrid, Power Park and Virtual Utilities, etc. are proposed. In Europe, DISPOWER or Smart Grid is under developing. In Japan, FRIENDS and Demand Area Network System etc. are proposed and tested in real sites. In this paper, first, general concepts of such new type power delivery systems and new businesses expected to be created by using DGs are introduced. Then, recent research activities in this area in Japan are introduced so as to stimulate new business opportunities. In the later part of this paper, related NEDO's demonstrative projects are introduced. NEDO is the largest public R&D management organization and promoting several projects regarding grid connecting issues on the power system. Those projects were planned to solve several problems on the power system where distributed renewable energy resources are installed.

Electromagnetic compatibility of PLC adapters for in-home/domestic networks

NASA Astrophysics Data System (ADS)

Potisk, Lukas; Hallon, Jozef; Orgon, Milos; Fujdiak, Radek

2018-01-01

The use of programable logic controllers (PLC) technology in electrical networks 230 V causes electromagnetic radiation that interferes with other electrical equipment connected to the network [1-4]. Therefore, this article describes the issues of electromagnetic compatibility (EMC) of new PLC adapters used in IP broadband services in a multi-user environment. The measurements of disturbing electromagnetic field originated in PLC adapters were made in a certified laboratory EMC (laboratory of electromagnetic compatibility) in the Institute of Electrical Engineering at Faculty of Electrical Engineering and Information Technology of the Slovak University of Technology in Bratislava. The measured spectra of the radiated electromagnetic field will be compared with the results obtained when testing older PLC modems [5].

DC grid for home applications

NASA Astrophysics Data System (ADS)

Elangovan, D.; Archana, R.; Jayadeep, V. J.; Nithin, M.; Arunkumar, G.

2017-11-01

More than fifty percent Indian population do not have access to electricity in daily lives. The distance between the power generating stations and the distribution centers forms one of the main reasons for lack of electrification in rural and remote areas. Here lies the importance of decentralization of power generation through renewable energy resources. In the present world, electricity is predominantly powered by alternating current, but most day to day devices like LED lamps, computers and electrical vehicles, all run on DC power. By directly supplying DC to these loads, the number of power conversion stages was reduced, and overall system efficiency increases. Replacing existing AC network with DC is a humongous task, but with power electronic techniques, this project intends to implement DC grid at a household level in remote and rural areas. Proposed work was designed and simulated successfully for various loads amounting to 250 W through appropriate power electronic convertors. Maximum utilization of the renewable sources for domestic and commercial application was achieved with the proposed DC topology.

A case study of the Thunderstorm Research International Project storm of July 11, 1978. I - Analysis of the data base

NASA Technical Reports Server (NTRS)

Nisbet, John S.; Barnard, Theresa A.; Forbes, Gregory S.; Krider, E. Philip; Lhermitte, Roger

1990-01-01

The data obtained at the time of the Thunderstorm Research International Project storm at the Kennedy Space Center on July 11, 1978 are analyzed in a model-independent manner. The data base included data from three Doppler radars, a lightning detection and ranging system and a network of 25 electric field mills, and rain gages. Electric field measurements were used to analyze the charge moments transferred by lightning flashes, and the data were fitted to Weibull distributions; these were used to estimate statistical parameters of the lightning for both intracloud and cloud-to-ground flashes and to estimate the fraction of the flashes which were below the observation threshold. The displacement and the conduction current densities were calculated from electric field measurements between flashes. These values were used to derive the magnitudes and the locations of dipole and monopole generators by least squares fitting the measured Maxwell current densities to the displacement-dominated equations.

EMP/GMD Phase 0 Report, A Review of EMP Hazard Environments and Impacts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivera, Michael Kelly; Backhaus, Scott N.; Woodroffe, Jesse Richard

The purpose of this study is to determine methods to analyze the hazard environments, impacts, and consequences of different sources of electromagnetic pulse (EMP), including nuclear electromagnetic pulse (NEMP) and geomagnetic disturbance (GMD) on the U.S. electric power infrastructures and to use those methods to determine EMP and GMD events of concern. The study will be carried out in four phases, each of which will provide higher levels of analytic fidelity that focuses on those EMP/GMD sources and events that create significant consequences, or whose consequences are sufficiently uncertain, to require more in-depth study. This study will leverage the bestmore » experimental data; device, equipment and system models; and simulation tools currently available. This study focuses primarily on the bulk electric system (BES) including large generating stations, large power transformers, the transmission network, and transmission system protection. Electrical distribution systems may potentially be included, if warranted, after consideration of the consequences for the bulk power system.« less

Incipient fault diagnosis of power transformers using optical spectro-photometric technique

NASA Astrophysics Data System (ADS)

Hussain, K.; Karmakar, Subrata

2015-06-01

Power transformers are the vital equipment in the network of power generation, transmission and distribution. Mineral oil in oil-filled transformers plays very important role as far as electrical insulation for the winding and cooling of the transformer is concerned. As transformers are always under the influence of electrical and thermal stresses, incipient faults like partial discharge, sparking and arcing take place. As a result, mineral oil deteriorates there by premature failure of the transformer occurs causing huge losses in terms of revenue and assets. Therefore, the transformer health condition has to be monitored continuously. The Dissolved Gas Analysis (DGA) is being extensively used for this purpose, but it has some drawbacks like it needs carrier gas, regular instrument calibration, etc. To overcome these drawbacks, Ultraviolet (UV) -Visible and Fourier Transform Infrared (FTIR) Spectro-photometric techniques are used as diagnostic tools for investigating the degraded transformer oil affected by electrical, mechanical and thermal stresses. The technique has several advantages over the conventional DGA technique.

Ancillary-service costs for 12 US electric utilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirby, B.; Hirst, E.

1996-03-01

Ancillary services are those functions performed by electrical generating, transmission, system-control, and distribution-system equipment and people to support the basic services of generating capacity, energy supply, and power delivery. The Federal Energy Regulatory Commission defined ancillary services as ``those services necessary to support the transmission of electric power from seller to purchaser given the obligations of control areas and transmitting utilities within those control areas to maintain reliable operations of the interconnected transmission system.`` FERC divided these services into three categories: ``actions taken to effect the transaction (such as scheduling and dispatching services) , services that are necessary to maintainmore » the integrity of the transmission system [and] services needed to correct for the effects associated with undertaking a transaction.`` In March 1995, FERC published a proposed rule to ensure open and comparable access to transmission networks throughout the country. The rule defined six ancillary services and developed pro forma tariffs for these services: scheduling and dispatch, load following, system protection, energy imbalance, loss compensation, and reactive power/voltage control.« less

Processing and Characterization of a Novel Distributed Strain Sensor Using Carbon Nanotube-Based Nonwoven Composites

PubMed Central

Dai, Hongbo; Thostenson, Erik T.; Schumacher, Thomas

2015-01-01

This paper describes the development of an innovative carbon nanotube-based non-woven composite sensor that can be tailored for strain sensing properties and potentially offers a reliable and cost-effective sensing option for structural health monitoring (SHM). This novel strain sensor is fabricated using a readily scalable process of coating Carbon nanotubes (CNT) onto a nonwoven carrier fabric to form an electrically-isotropic conductive network. Epoxy is then infused into the CNT-modified fabric to form a free-standing nanocomposite strain sensor. By measuring the changes in the electrical properties of the sensing composite the deformation can be measured in real-time. The sensors are repeatable and linear up to 0.4% strain. Highest elastic strain gage factors of 1.9 and 4.0 have been achieved in the longitudinal and transverse direction, respectively. Although the longitudinal gage factor of the newly formed nanocomposite sensor is close to some metallic foil strain gages, the proposed sensing methodology offers spatial coverage, manufacturing customizability, distributed sensing capability as well as transverse sensitivity. PMID:26197323

Development of Voltage Regulation Plan by Composing Subsystem with the SFES for DC On-line Electric Vehicle

NASA Astrophysics Data System (ADS)

Jung, S.; Lee, J. H.; Yoon, M.; Lee, H.; Jang, G.

The study of the application process of the relatively small size 'Superconducting Flywheel Energy Storage (SFES)' system is conducted to regulate voltage fluctuation of the DC On-Line Electric Vehicle (OLEV) system, which is designed by using DC power system network. It is recommended to construct the power conversion system nearby the substation because the charging system is under the low voltage. But as the system is usually built around urban area and it makes hard to construct the subsystems at every station, voltage drop can occur in power supply inverter that is some distance from the substation. As the alternative of this issue, DC distribution system is recently introduced and has possibility to solve the above issue. In this paper, SFES is introduced to solve the voltage drop under the low voltage distribution system by using the concept of the proposed DC OLEV which results in building the longer distance power supply system. The simulation to design the SFES by using DC power flow analysis is carried out and it is verified in this paper.

Conductive network formation of carbon nanotubes in elastic polymer microfibers and its effect on the electrical conductance: Experiment and simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, Hyun Woo; Kim, Jeongmin; Sung, Bong June, E-mail: jjpark@chonnam.ac.kr, E-mail: bjsung@sogang.ac.kr

We investigate how the electrical conductance of microfibers (made of polymers and conductive nanofillers) decreases upon uniaxial deformation by performing both experiments and simulations. Even though various elastic conductors have been developed due to promising applications for deformable electronic devices, the mechanism at a molecular level for electrical conductance change has remained elusive. Previous studies proposed that the decrease in electrical conductance would result from changes in either distances or contact numbers between conductive fillers. In this work, we prepare microfibers of single walled carbon nanotubes (SWCNTs)/polyvinyl alcohol composites and investigate the electrical conductance and the orientation of SWCNTs uponmore » uniaxial deformation. We also perform extensive Monte Carlo simulations, which reproduce experimental results for the relative decrease in conductance and the SWCNTs orientation. We investigate the electrical networks of SWCNTs in microfibers and find that the decrease in the electrical conductance upon uniaxial deformation should be attributed to a subtle change in the topological structure of the electrical network.« less

Evaluation of corrosion and scaling tendency indices in a drinking water distribution system: a case study of Bandar Abbas city, Iran.

PubMed

Alipour, Vali; Dindarloo, Kavoos; Mahvi, Amir Hossein; Rezaei, Leila

2015-03-01

Corrosion and scaling is a major problem in water distribution systems, thus evaluation of water corrosivity properties is a routine test in water networks. To evaluate water stability in the Bandar Abbas water distribution system, the network was divided into 15 clusters and 45 samples were taken. Langelier, Ryznar, Puckorius, Larson-Skold (LS) and Aggressive indices were determined and compared to the marble test. The mean parameters included were pH (7.8 ± 0.1), electrical conductivity (1,083.9 ± 108.7 μS/cm), total dissolved solids (595.7 ± 54.7 mg/L), Cl (203.5 ± 18.7 mg/L), SO₄(174.7 ± 16.0 mg/L), alkalinity (134.5 ± 9.7 mg/L), total hardness (156.5 ± 9.3 mg/L), HCO₃(137.4 ± 13.0 mg/L) and calcium hardness (71.8 ± 4.3 mg/L). According to the Ryznar, Puckorius and Aggressive Indices, all samples were stable; based on the Langelier Index, 73% of samples were slightly corrosive and the rest were scale forming; according to the LS index, all samples were corrosive. Marble test results showed tested water of all 15 clusters tended to scale formation. Water in Bandar Abbas is slightly scale forming. The most appropriate indices for the network conditions are the Aggressive, Puckorius and Ryznar indices that were consistent with the marble test.

GABA and Gap Junctions in the Development of Synchronized Activity in Human Pluripotent Stem Cell-Derived Neural Networks

PubMed Central

Mäkinen, Meeri Eeva-Liisa; Ylä-Outinen, Laura; Narkilahti, Susanna

2018-01-01

The electrical activity of the brain arises from single neurons communicating with each other. However, how single neurons interact during early development to give rise to neural network activity remains poorly understood. We studied the emergence of synchronous neural activity in human pluripotent stem cell (hPSC)-derived neural networks simultaneously on a single-neuron level and network level. The contribution of gamma-aminobutyric acid (GABA) and gap junctions to the development of synchronous activity in hPSC-derived neural networks was studied with GABA agonist and antagonist and by blocking gap junctional communication, respectively. We characterized the dynamics of the network-wide synchrony in hPSC-derived neural networks with high spatial resolution (calcium imaging) and temporal resolution microelectrode array (MEA). We found that the emergence of synchrony correlates with a decrease in very strong GABA excitation. However, the synchronous network was found to consist of a heterogeneous mixture of synchronously active cells with variable responses to GABA, GABA agonists and gap junction blockers. Furthermore, we show how single-cell distributions give rise to the network effect of GABA, GABA agonists and gap junction blockers. Finally, based on our observations, we suggest that the earliest form of synchronous neuronal activity depends on gap junctions and a decrease in GABA induced depolarization but not on GABAA mediated signaling. PMID:29559893

Micro-economic analysis of the physical constrained markets: game theory application to competitive electricity markets

NASA Astrophysics Data System (ADS)

Bompard, E.; Ma, Y. C.; Ragazzi, E.

2006-03-01

Competition has been introduced in the electricity markets with the goal of reducing prices and improving efficiency. The basic idea which stays behind this choice is that, in competitive markets, a greater quantity of the good is exchanged at a lower price, leading to higher market efficiency. Electricity markets are pretty different from other commodities mainly due to the physical constraints related to the network structure that may impact the market performance. The network structure of the system on which the economic transactions need to be undertaken poses strict physical and operational constraints. Strategic interactions among producers that game the market with the objective of maximizing their producer surplus must be taken into account when modeling competitive electricity markets. The physical constraints, specific of the electricity markets, provide additional opportunity of gaming to the market players. Game theory provides a tool to model such a context. This paper discussed the application of game theory to physical constrained electricity markets with the goal of providing tools for assessing the market performance and pinpointing the critical network constraints that may impact the market efficiency. The basic models of game theory specifically designed to represent the electricity markets will be presented. IEEE30 bus test system of the constrained electricity market will be discussed to show the network impacts on the market performances in presence of strategic bidding behavior of the producers.

29 CFR 1915.181 - Electrical circuits and distribution boards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Electrical circuits and distribution boards. 1915.181... Electrical Machinery § 1915.181 Electrical circuits and distribution boards. (a) The provisions of this... employee is permitted to work on an electrical circuit, except when the circuit must remain energized for...

Quantum key distribution with an entangled light emitting diode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dzurnak, B.; Stevenson, R. M.; Nilsson, J.

Measurements performed on entangled photon pairs shared between two parties can allow unique quantum cryptographic keys to be formed, creating secure links between users. An advantage of using such entangled photon links is that they can be adapted to propagate entanglement to end users of quantum networks with only untrusted nodes. However, demonstrations of quantum key distribution with entangled photons have so far relied on sources optically excited with lasers. Here, we realize a quantum cryptography system based on an electrically driven entangled-light-emitting diode. Measurement bases are passively chosen and we show formation of an error-free quantum key. Our measurementsmore » also simultaneously reveal Bell's parameter for the detected light, which exceeds the threshold for quantum entanglement.« less

Quantifying Availability in SCADA Environments Using the Cyber Security Metric MFC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aissa, Anis Ben; Rabai, Latifa Ben Arfa; Abercrombie, Robert K

2014-01-01

Supervisory Control and Data Acquisition (SCADA) systems are distributed networks dispersed over large geographic areas that aim to monitor and control industrial processes from remote areas and/or a centralized location. They are used in the management of critical infrastructures such as electric power generation, transmission and distribution, water and sewage, manufacturing/industrial manufacturing as well as oil and gas production. The availability of SCADA systems is tantamount to assuring safety, security and profitability. SCADA systems are the backbone of the national cyber-physical critical infrastructure. Herein, we explore the definition and quantification of an econometric measure of availability, as it applies tomore » SCADA systems; our metric is a specialization of the generic measure of mean failure cost.« less

Quantum key distribution with an entangled light emitting diode

NASA Astrophysics Data System (ADS)

Dzurnak, B.; Stevenson, R. M.; Nilsson, J.; Dynes, J. F.; Yuan, Z. L.; Skiba-Szymanska, J.; Farrer, I.; Ritchie, D. A.; Shields, A. J.

2015-12-01

Measurements performed on entangled photon pairs shared between two parties can allow unique quantum cryptographic keys to be formed, creating secure links between users. An advantage of using such entangled photon links is that they can be adapted to propagate entanglement to end users of quantum networks with only untrusted nodes. However, demonstrations of quantum key distribution with entangled photons have so far relied on sources optically excited with lasers. Here, we realize a quantum cryptography system based on an electrically driven entangled-light-emitting diode. Measurement bases are passively chosen and we show formation of an error-free quantum key. Our measurements also simultaneously reveal Bell's parameter for the detected light, which exceeds the threshold for quantum entanglement.

Modeling Geoelectric Fields and Geomagnetically Induced Currents Around New Zealand to Explore GIC in the South Island's Electrical Transmission Network

NASA Astrophysics Data System (ADS)

Divett, T.; Ingham, M.; Beggan, C. D.; Richardson, G. S.; Rodger, C. J.; Thomson, A. W. P.; Dalzell, M.

2017-10-01

Transformers in New Zealand's South Island electrical transmission network have been impacted by geomagnetically induced currents (GIC) during geomagnetic storms. We explore the impact of GIC on this network by developing a thin-sheet conductance (TSC) model for the region, a geoelectric field model, and a GIC network model. (The TSC is composed of a thin-sheet conductance map with underlying layered resistivity structure.) Using modeling approaches that have been successfully used in the United Kingdom and Ireland, we applied a thin-sheet model to calculate the electric field as a function of magnetic field and ground conductance. We developed a TSC model based on magnetotelluric surveys, geology, and bathymetry, modified to account for offshore sediments. Using this representation, the thin sheet model gave good agreement with measured impedance vectors. Driven by a spatially uniform magnetic field variation, the thin-sheet model results in electric fields dominated by the ocean-land boundary with effects due to the deep ocean and steep terrain. There is a strong tendency for the electric field to align northwest-southeast, irrespective of the direction of the magnetic field. Applying this electric field to a GIC network model, we show that modeled GIC are dominated by northwest-southeast transmission lines rather than east-west lines usually assumed to dominate.

Developing a tissue-engineered neural-electrical relay using encapsulated neuronal constructs on conducting polymer fibers.

PubMed

Cullen, D Kacy; R Patel, Ankur; Doorish, John F; Smith, Douglas H; Pfister, Bryan J

2008-12-01

Neural-electrical interface platforms are being developed to extracellularly monitor neuronal population activity. Polyaniline-based electrically conducting polymer fibers are attractive substrates for sustained functional interfaces with neurons due to their flexibility, tailored geometry and controlled electro-conductive properties. In this study, we addressed the neurobiological considerations of utilizing small diameter (<400 microm) fibers consisting of a blend of electrically conductive polyaniline and polypropylene (PA-PP) as the backbone of encapsulated tissue-engineered neural-electrical relays. We devised new approaches to promote survival, adhesion and neurite outgrowth of primary dorsal root ganglion neurons on PA-PP fibers. We attained a greater than ten-fold increase in the density of viable neurons on fiber surfaces to approximately 700 neurons mm(-2) by manipulating surrounding surface charges to bias settling neuronal suspensions toward fibers coated with cell-adhesive ligands. This stark increase in neuronal density resulted in robust neuritic extension and network formation directly along the fibers. Additionally, we encapsulated these neuronal networks on PA-PP fibers using agarose to form a protective barrier while potentially facilitating network stability. Following encapsulation, the neuronal networks maintained integrity, high viability (>85%) and intimate adhesion to PA-PP fibers. These efforts accomplished key prerequisites for the establishment of functional electrical interfaces with neuronal populations using small diameter PA-PP fibers-specifically, improved neurocompatibility, high-density neuronal adhesion and neuritic network development directly on fiber surfaces.

Electrode material comprising graphene-composite materials in a graphite network

DOEpatents

Kung, Harold H.; Lee, Jung K.

2014-07-15

A durable electrode material suitable for use in Li ion batteries is provided. The material is comprised of a continuous network of graphite regions integrated with, and in good electrical contact with a composite comprising graphene sheets and an electrically active material, such as silicon, wherein the electrically active material is dispersed between, and supported by, the graphene sheets.

Electrode material comprising graphene-composite materials in a graphite network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kung, Harold H.; Lee, Jung K.

A durable electrode material suitable for use in Li ion batteries is provided. The material is comprised of a continuous network of graphite regions integrated with, and in good electrical contact with a composite comprising graphene sheets and an electrically active material, such as silicon, wherein the electrically active material is dispersed between, and supported by, the graphene sheets.

Study on probability distribution of prices in electricity market: A case study of zhejiang province, china

NASA Astrophysics Data System (ADS)

Zhou, H.; Chen, B.; Han, Z. X.; Zhang, F. Q.

2009-05-01

The study on probability density function and distribution function of electricity prices contributes to the power suppliers and purchasers to estimate their own management accurately, and helps the regulator monitor the periods deviating from normal distribution. Based on the assumption of normal distribution load and non-linear characteristic of the aggregate supply curve, this paper has derived the distribution of electricity prices as the function of random variable of load. The conclusion has been validated with the electricity price data of Zhejiang market. The results show that electricity prices obey normal distribution approximately only when supply-demand relationship is loose, whereas the prices deviate from normal distribution and present strong right-skewness characteristic. Finally, the real electricity markets also display the narrow-peak characteristic when undersupply occurs.

High resolution structural characterisation of laser-induced defect clusters inside diamond

NASA Astrophysics Data System (ADS)

Salter, Patrick S.; Booth, Martin J.; Courvoisier, Arnaud; Moran, David A. J.; MacLaren, Donald A.

2017-08-01

Laser writing with ultrashort pulses provides a potential route for the manufacture of three-dimensional wires, waveguides, and defects within diamond. We present a transmission electron microscopy study of the intrinsic structure of the laser modifications and reveal a complex distribution of defects. Electron energy loss spectroscopy indicates that the majority of the irradiated region remains as sp3 bonded diamond. Electrically conductive paths are attributed to the formation of multiple nano-scale, sp2-bonded graphitic wires and a network of strain-relieving micro-cracks.

Protection coordination of the Kennedy Space Center electric distribution network

NASA Technical Reports Server (NTRS)

1976-01-01

A computer technique is described for visualizing the coordination and protection of any existing system of devices and settings by plotting the tripping characteristics of the involved devices on a common basis. The program determines the optimum settings of a given set of protective devices and configuration in the sense of the best expected coordinated operation of these devices. Subroutines are given for simulating time versus current characteristics of the different relays, circuit breakers, and fuses in the system; coordination index computation; protection checks; plotting; and coordination optimation.

Isolation contactor state control system

DOEpatents

Bissontz, Jay E.

2017-05-16

A controller area network (CAN) installed on a hybrid electric vehicle provides one node with control of high voltage power distribution system isolation contactors and the capacity to energize a secondary electro-mechanical relay device. The output of the secondary relay provides a redundant and persistent backup signal to the output of the node. The secondary relay is relatively immune to CAN message traffic interruptions and, as a result, the high voltage isolation contactor(s) are less likely to transition open in the event that the intelligent output driver should fail.

Alicudi project

NASA Astrophysics Data System (ADS)

Arcidiacono, V.; Corsi, S.; Iliceto, A.; Previ, A.; Taschini, A.

Design features and goals of the photovoltaic array power system for Alicudi Island hamlets are described. The array will have two 40 kWe sections, a 3 kAh battery system, an inverter to assure three-phase, ac current, a data acquisition system, and a 60 kVA diesel back-up system. The semi-arid conic volcanic island has terraces and a slope ideally suited to installation of the array. A computer simulation was developed to optimize the output and load profile matching using historical insolation data. A block diagram is provided of the electricity distribution network.

Design and Development of a 200-kW Turbo-Electric Distributed Propulsion Testbed

NASA Technical Reports Server (NTRS)

Papathakis, Kurt V.; Kloesel, Kurt J.; Lin, Yohan; Clarke, Sean; Ediger, Jacob J.; Ginn, Starr

2016-01-01

The National Aeronautics and Space Administration (NASA) Armstrong Flight Research Center (AFRC) (Edwards, California) is developing a Hybrid-Electric Integrated Systems Testbed (HEIST) Testbed as part of the HEIST Project, to study power management and transition complexities, modular architectures, and flight control laws for turbo-electric distributed propulsion technologies using representative hardware and piloted simulations. Capabilities are being developed to assess the flight readiness of hybrid electric and distributed electric vehicle architectures. Additionally, NASA will leverage experience gained and assets developed from HEIST to assist in flight-test proposal development, flight-test vehicle design, and evaluation of hybrid electric and distributed electric concept vehicles for flight safety. The HEIST test equipment will include three trailers supporting a distributed electric propulsion wing, a battery system and turbogenerator, dynamometers, and supporting power and communication infrastructure, all connected to the AFRC Core simulation. Plans call for 18 high performance electric motors that will be powered by batteries and the turbogenerator, and commanded by a piloted simulation. Flight control algorithms will be developed on the turbo-electric distributed propulsion system.

Storage of electric and magnetic energy in passive nonreciprocal networks

NASA Technical Reports Server (NTRS)

Smith, W. E.

1969-01-01

Examination of the relation of stored electric and magnetic energy within a system to the terminal behavior of nonreciprocal passive networks shows both similarities and important differences between wholly reciprocal systems and systems containing nonreciprocal elements.

Characterisation of electrical resistance for CMC Materials up to 1200 °C

NASA Astrophysics Data System (ADS)

Stäbler, T.; Böhrk, H.; Voggenreiter, H.

2017-12-01

Damage to thermal protection systems (TPS) during atmospheric re-entry is a severe safety issue, especially when considering re-usability of space transportation systems. There is a need for structural health monitoring systems and non-destructive inspection methods. However, damages are hard to detect. When ceramic matrix composites, in this case carbon fibre reinforced silicon carbide (C/C-SiC), are used as a TPS, the electrical properties of the present semiconductor material can be used for health monitoring, since the resistivity changes with damage, strain and temperature. In this work the electrical resistivity as a function of the material temperature is analysed eliminating effects of thermal electricity and the thermal coefficient of electrical resistance is determined. A sensor network is applied for locally and time resolved monitoring of the 300 mm x 120 mm x 3 mm panel shaped samples. Since the material is used for atmospheric re-entry it needs to be characterised for a wide range of temperatures, in this case as high as 1200 °C. Therefore, experiments in an inductively heated test bench were conducted. Firstly, a reference sample was used with thermocouples for characterising the temperature distribution across the sample surface. Secondly, electrical resistance under heat load was measured, time and spatially resolved. Results will be shown and discussed in terms of resistance dependence on temperature, thermal coefficient of electrical resistance, thermal electricity and electrical path orientation including an analysis on effective conducting cross section. Conversely, the thermal coefficient can also be used to determine the material temperature as a function of electrical resistance.

Energy Management of Smart Distribution Systems

NASA Astrophysics Data System (ADS)

Ansari, Bananeh

Electric power distribution systems interface the end-users of electricity with the power grid. Traditional distribution systems are operated in a centralized fashion with the distribution system owner or operator being the only decision maker. The management and control architecture of distribution systems needs to gradually transform to accommodate the emerging smart grid technologies, distributed energy resources, and active electricity end-users or prosumers. The content of this document concerns with developing multi-task multi-objective energy management schemes for: 1) commercial/large residential prosumers, and 2) distribution system operator of a smart distribution system. The first part of this document describes a method of distributed energy management of multiple commercial/ large residential prosumers. These prosumers not only consume electricity, but also generate electricity using their roof-top solar photovoltaics systems. When photovoltaics generation is larger than local consumption, excess electricity will be fed into the distribution system, creating a voltage rise along the feeder. Distribution system operator cannot tolerate a significant voltage rise. ES can help the prosumers manage their electricity exchanges with the distribution system such that minimal voltage fluctuation occurs. The proposed distributed energy management scheme sizes and schedules each prosumer's ES to reduce the electricity bill and mitigate voltage rise along the feeder. The second part of this document focuses on emergency energy management and resilience assessment of a distribution system. The developed emergency energy management system uses available resources and redundancy to restore the distribution system's functionality fully or partially. The success of the restoration maneuver depends on how resilient the distribution system is. Engineering resilience terminology is used to evaluate the resilience of distribution system. The proposed emergency energy management scheme together with resilience assessment increases the distribution system operator's preparedness for emergency events.

Role of atomistic structure in the stochastic nature of conductivity in substoichiometric tantalum pentoxide

DOE PAGES

Bondi, Robert James; Fox, Brian Philip; Marinella, Matthew J.

2016-03-22

In this study, first-principles calculations of electrical conductivity (σ o) are revisited to determine the atomistic origin of its stochasticity in a distribution generated from sampling 14 ab-initio molecular dynamics configurations from 10 independently quenched models (n = 140) of substoichiometric amorphous Ta 2O 5, where each structure contains a neutral O monovacancy (V O 0). Structural analysis revealed a distinct minimum Ta-Ta separation (dimer/trimer) corresponding to each V O 0 location. Bader charge decomposition using a commonality analysis approach based on the σ o distribution extremes revealed nanostructural signatures indicating that both the magnitude and distribution of cationic chargemore » on the Ta subnetwork have a profound influence on σ o. Furthermore, visualization of local defect structures and their electron densities reinforces these conclusions and suggests σ o in the amorphous oxide is best suppressed by a highly charged, compact Ta cation shell that effectively screens and minimizes localized V O 0 interaction with the a-Ta 2O 5 network; conversely, delocalization of V O 0 corresponds to metallic character and high σ o. The random network of a-Ta 2O 5 provides countless variations of an ionic configuration scaffold in which small perturbations affect the electronic charge distribution and result in a fixed-stoichiometry distribution of σ o; consequently, precisely controlled and highly repeatable oxide fabrication processes are likely paramount for advancement of resistive memory technologies.« less

Partial Discharge Monitoring on Metal-Enclosed Switchgear with Distributed Non-Contact Sensors.

PubMed

Zhang, Chongxing; Dong, Ming; Ren, Ming; Huang, Wenguang; Zhou, Jierui; Gao, Xuze; Albarracín, Ricardo

2018-02-11

Metal-enclosed switchgear, which are widely used in the distribution of electrical energy, play an important role in power distribution networks. Their safe operation is directly related to the reliability of power system as well as the power quality on the consumer side. Partial discharge detection is an effective way to identify potential faults and can be utilized for insulation diagnosis of metal-enclosed switchgear. The transient earth voltage method, an effective non-intrusive method, has substantial engineering application value for estimating the insulation condition of switchgear. However, the practical application effectiveness of TEV detection is not satisfactory because of the lack of a TEV detection application method, i.e., a method with sufficient technical cognition and analysis. This paper proposes an innovative online PD detection system and a corresponding application strategy based on an intelligent feedback distributed TEV wireless sensor network, consisting of sensing, communication, and diagnosis layers. In the proposed system, the TEV signal or status data are wirelessly transmitted to the terminal following low-energy signal preprocessing and acquisition by TEV sensors. Then, a central server analyzes the correlation of the uploaded data and gives a fault warning level according to the quantity, trend, parallel analysis, and phase resolved partial discharge pattern recognition. In this way, a TEV detection system and strategy with distributed acquisition, unitized fault warning, and centralized diagnosis is realized. The proposed system has positive significance for reducing the fault rate of medium voltage switchgear and improving its operation and maintenance level.

A Custom Approach for a Flexible, Real-Time and Reliable Software Defined Utility.

PubMed

Zaballos, Agustín; Navarro, Joan; Martín De Pozuelo, Ramon

2018-02-28

Information and communication technologies (ICTs) have enabled the evolution of traditional electric power distribution networks towards a new paradigm referred to as the smart grid. However, the different elements that compose the ICT plane of a smart grid are usually conceived as isolated systems that typically result in rigid hardware architectures, which are hard to interoperate, manage and adapt to new situations. In the recent years, software-defined systems that take advantage of software and high-speed data network infrastructures have emerged as a promising alternative to classic ad hoc approaches in terms of integration, automation, real-time reconfiguration and resource reusability. The purpose of this paper is to propose the usage of software-defined utilities (SDUs) to address the latent deployment and management limitations of smart grids. More specifically, the implementation of a smart grid's data storage and management system prototype by means of SDUs is introduced, which exhibits the feasibility of this alternative approach. This system features a hybrid cloud architecture able to meet the data storage requirements of electric utilities and adapt itself to their ever-evolving needs. Conducted experimentations endorse the feasibility of this solution and encourage practitioners to point their efforts in this direction.

A Custom Approach for a Flexible, Real-Time and Reliable Software Defined Utility

PubMed Central

2018-01-01

Information and communication technologies (ICTs) have enabled the evolution of traditional electric power distribution networks towards a new paradigm referred to as the smart grid. However, the different elements that compose the ICT plane of a smart grid are usually conceived as isolated systems that typically result in rigid hardware architectures, which are hard to interoperate, manage and adapt to new situations. In the recent years, software-defined systems that take advantage of software and high-speed data network infrastructures have emerged as a promising alternative to classic ad hoc approaches in terms of integration, automation, real-time reconfiguration and resource reusability. The purpose of this paper is to propose the usage of software-defined utilities (SDUs) to address the latent deployment and management limitations of smart grids. More specifically, the implementation of a smart grid’s data storage and management system prototype by means of SDUs is introduced, which exhibits the feasibility of this alternative approach. This system features a hybrid cloud architecture able to meet the data storage requirements of electric utilities and adapt itself to their ever-evolving needs. Conducted experimentations endorse the feasibility of this solution and encourage practitioners to point their efforts in this direction. PMID:29495599

Flow distribution analysis on the cooling tube network of ITER thermal shield

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nam, Kwanwoo; Chung, Wooho; Noh, Chang Hyun

2014-01-29

Thermal shield (TS) is to be installed between the vacuum vessel or the cryostat and the magnets in ITER tokamak to reduce the thermal radiation load to the magnets operating at 4.2K. The TS is cooled by pressurized helium gas at the inlet temperature of 80K. The cooling tube is welded on the TS panel surface and the composed flow network of the TS cooling tubes is complex. The flow rate in each panel should be matched to the thermal design value for effective radiation shielding. This paper presents one dimensional analysis on the flow distribution of cooling tube networkmore » for the ITER TS. The hydraulic cooling tube network is modeled by an electrical analogy. Only the cooling tube on the TS surface and its connecting pipe from the manifold are considered in the analysis model. Considering the frictional factor and the local loss in the cooling tube, the hydraulic resistance is expressed as a linear function with respect to mass flow rate. Sub-circuits in the TS are analyzed separately because each circuit is controlled by its own control valve independently. It is found that flow rates in some panels are insufficient compared with the design values. In order to improve the flow distribution, two kinds of design modifications are proposed. The first one is to connect the tubes of the adjacent panels. This will increase the resistance of the tube on the panel where the flow rate is excessive. The other design suggestion is that an orifice is installed at the exit of tube routing where the flow rate is to be reduced. The analysis for the design suggestions shows that the flow mal-distribution is improved significantly.« less

Geometry of complex networks and topological centrality

NASA Astrophysics Data System (ADS)

Ranjan, Gyan; Zhang, Zhi-Li

2013-09-01

We explore the geometry of complex networks in terms of an n-dimensional Euclidean embedding represented by the Moore-Penrose pseudo-inverse of the graph Laplacian (L). The squared distance of a node i to the origin in this n-dimensional space (lii+), yields a topological centrality index, defined as C∗(i)=1/lii+. In turn, the sum of reciprocals of individual node centralities, ∑i1/C∗(i)=∑ilii+, or the trace of L, yields the well-known Kirchhoff index (K), an overall structural descriptor for the network. To put into context this geometric definition of centrality, we provide alternative interpretations of the proposed indices that connect them to meaningful topological characteristics - first, as forced detour overheads and frequency of recurrences in random walks that has an interesting analogy to voltage distributions in the equivalent electrical network; and then as the average connectedness of i in all the bi-partitions of the graph. These interpretations respectively help establish the topological centrality (C∗(i)) of node i as a measure of its overall position as well as its overall connectedness in the network; thus reflecting the robustness of i to random multiple edge failures. Through empirical evaluations using synthetic and real world networks, we demonstrate how the topological centrality is better able to distinguish nodes in terms of their structural roles in the network and, along with Kirchhoff index, is appropriately sensitive to perturbations/re-wirings in the network.

Application of Phasor Measurement Units for Protection of Distribution Networks with High Penetration of Photovoltaic Sources

NASA Astrophysics Data System (ADS)

Meskin, Matin

The rate of the integration of distributed generation (DG) units to the distribution level to meet the growth in demand increases as a reasonable replacement for costly network expansion. This integration brings many advantages to the consumers and power grids, as well as giving rise to more challenges in relation to protection and control. Recent research has brought to light the negative effects of DG units on short circuit currents and overcurrent (OC) protection systems in distribution networks. Change in the direction of fault current flow, increment or decrement of fault current magnitude, blindness of protection, feeder sympathy trip, nuisance trip of interrupting devices, and the disruption of coordination between protective devices are some potential impacts of DG unit integration. Among other types of DG units, the integration of renewable energy resources into the electric grid has seen a vast improvement in recent years. In particular, the interconnection of photovoltaic (PV) sources to the medium voltage (MV) distribution networks has experienced a rapid increase in the last decade. In this work, the effect of PV source on conventional OC relays in MV distribution networks is shown. It is indicated that the PV output fluctuation, due to changes in solar radiation, causes the magnitude and direction of the current to change haphazardly. These variations may result in the poor operation of OC relays as the main protective devices in the MV distribution networks. In other words, due to the bi-directional power flow characteristic and the fluctuation of current magnitude occurring in the presence of PV sources, a specific setting of OC relays is difficult to realize. Therefore, OC relays may operate in normal conditions. To improve the OC relay operation, a voltage-dependent-overcurrent protection is proposed. Although, this new method prevents the OC relay from maloperation, its ability to detect earth faults and high impedance faults is poor. Thus, a comprehensive protective system is suggested at the end of the dissertation. The proposed method is based on the application of the phasor measurement unit (PMU) and the differential protection method. All of the current magnitudes and angles are collected by PMU and are sent to the phasor data concentrator (PDC), where a differential protection algorithm is applied to these data. If any fault is detected, the trip will be sent back to the corresponding circuit breakers across the network. Higher selectivity, sensitivity, and faster operation in the differential protection are superior to those of other protection schemes. Differential protection operates as unit protection, which means that it operates only when there is a fault in the protection zone. It does not function for faults occurring out of zone. Therefore, no coordination is required between differential protections across the power system. Moreover, the misoperation of this protective scheme is less likely as compared to other protection methods.

Surface dynamics of voltage-gated ion channels.

PubMed

Heine, Martin; Ciuraszkiewicz, Anna; Voigt, Andreas; Heck, Jennifer; Bikbaev, Arthur

2016-07-03

Neurons encode information in fast changes of the membrane potential, and thus electrical membrane properties are critically important for the integration and processing of synaptic inputs by a neuron. These electrical properties are largely determined by ion channels embedded in the membrane. The distribution of most ion channels in the membrane is not spatially uniform: they undergo activity-driven changes in the range of minutes to days. Even in the range of milliseconds, the composition and topology of ion channels are not static but engage in highly dynamic processes including stochastic or activity-dependent transient association of the pore-forming and auxiliary subunits, lateral diffusion, as well as clustering of different channels. In this review we briefly discuss the potential impact of mobile sodium, calcium and potassium ion channels and the functional significance of this for individual neurons and neuronal networks.

Determination of the Prosumer's Optimal Bids

NASA Astrophysics Data System (ADS)

Ferruzzi, Gabriella; Rossi, Federico; Russo, Angela

2015-12-01

This paper considers a microgrid connected with a medium-voltage (MV) distribution network. It is assumed that the microgrid, which is managed by a prosumer, operates in a competitive environment and participates in the day-ahead market. Then, as the first step of the short-term management problem, the prosumer must determine the bids to be submitted to the market. The offer strategy is based on the application of an optimization model, which is solved for different hourly price profiles of energy exchanged with the main grid. The proposed procedure is applied to a microgrid and four different its configurations were analyzed. The configurations consider the presence of thermoelectric units that only produce electricity, a boiler or/and cogeneration power plants for the thermal loads, and an electric storage system. The numerical results confirmed the numerous theoretical considerations that have been made.

Surface dynamics of voltage-gated ion channels

PubMed Central

Heine, Martin; Ciuraszkiewicz, Anna; Voigt, Andreas; Heck, Jennifer; Bikbaev, Arthur

2016-01-01

ABSTRACT Neurons encode information in fast changes of the membrane potential, and thus electrical membrane properties are critically important for the integration and processing of synaptic inputs by a neuron. These electrical properties are largely determined by ion channels embedded in the membrane. The distribution of most ion channels in the membrane is not spatially uniform: they undergo activity-driven changes in the range of minutes to days. Even in the range of milliseconds, the composition and topology of ion channels are not static but engage in highly dynamic processes including stochastic or activity-dependent transient association of the pore-forming and auxiliary subunits, lateral diffusion, as well as clustering of different channels. In this review we briefly discuss the potential impact of mobile sodium, calcium and potassium ion channels and the functional significance of this for individual neurons and neuronal networks. PMID:26891382

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattarai, Bishnu; Kouzelis, Konstantinos; Mendaza, Iker

The gradual active load penetration in low voltage distribution grids is expected to challenge their network capacity in the near future. Distribution system operators should for this reason resort to either costly grid reinforcements or to demand side management mechanisms. Since demand side management implementation is usually cheaper, it is also the favorable solution. To this end, this article presents a framework for handling grid limit violations, both voltage and current, to ensure a secure and qualitative operation of the distribution grid. This framework consists of two steps, namely a proactive centralized and subsequently a reactive decentralized control scheme. Themore » former is employed to balance the one hour ahead load while the latter aims at regulating the consumption in real-time. In both cases, the importance of fair use of electricity demand flexibility is emphasized. Thus, it is demonstrated that this methodology aids in keeping the grid status within preset limits while utilizing flexibility from all flexibility participants.« less

Physics-driven Spatiotemporal Regularization for High-dimensional Predictive Modeling: A Novel Approach to Solve the Inverse ECG Problem

NASA Astrophysics Data System (ADS)

Yao, Bing; Yang, Hui

2016-12-01

This paper presents a novel physics-driven spatiotemporal regularization (STRE) method for high-dimensional predictive modeling in complex healthcare systems. This model not only captures the physics-based interrelationship between time-varying explanatory and response variables that are distributed in the space, but also addresses the spatial and temporal regularizations to improve the prediction performance. The STRE model is implemented to predict the time-varying distribution of electric potentials on the heart surface based on the electrocardiogram (ECG) data from the distributed sensor network placed on the body surface. The model performance is evaluated and validated in both a simulated two-sphere geometry and a realistic torso-heart geometry. Experimental results show that the STRE model significantly outperforms other regularization models that are widely used in current practice such as Tikhonov zero-order, Tikhonov first-order and L1 first-order regularization methods.

Feature Selection and Parameters Optimization of SVM Using Particle Swarm Optimization for Fault Classification in Power Distribution Systems.

PubMed

Cho, Ming-Yuan; Hoang, Thi Thom

2017-01-01

Fast and accurate fault classification is essential to power system operations. In this paper, in order to classify electrical faults in radial distribution systems, a particle swarm optimization (PSO) based support vector machine (SVM) classifier has been proposed. The proposed PSO based SVM classifier is able to select appropriate input features and optimize SVM parameters to increase classification accuracy. Further, a time-domain reflectometry (TDR) method with a pseudorandom binary sequence (PRBS) stimulus has been used to generate a dataset for purposes of classification. The proposed technique has been tested on a typical radial distribution network to identify ten different types of faults considering 12 given input features generated by using Simulink software and MATLAB Toolbox. The success rate of the SVM classifier is over 97%, which demonstrates the effectiveness and high efficiency of the developed method.

A network thermodynamic method for numerical solution of the Nernst-Planck and Poisson equation system with application to ionic transport through membranes.

PubMed

Horno, J; González-Caballero, F; González-Fernández, C F

1990-01-01

Simple techniques of network thermodynamics are used to obtain the numerical solution of the Nernst-Planck and Poisson equation system. A network model for a particular physical situation, namely ionic transport through a thin membrane with simultaneous diffusion, convection and electric current, is proposed. Concentration and electric field profiles across the membrane, as well as diffusion potential, have been simulated using the electric circuit simulation program, SPICE. The method is quite general and extremely efficient, permitting treatments of multi-ion systems whatever the boundary and experimental conditions may be.

Neural network based short-term load forecasting using weather compensation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chow, T.W.S.; Leung, C.T.

This paper presents a novel technique for electric load forecasting based on neural weather compensation. The proposed method is a nonlinear generalization of Box and Jenkins approach for nonstationary time-series prediction. A weather compensation neural network is implemented for one-day ahead electric load forecasting. The weather compensation neural network can accurately predict the change of actual electric load consumption from the previous day. The results, based on Hong Kong Island historical load demand, indicate that this methodology is capable of providing a more accurate load forecast with a 0.9% reduction in forecast error.

The Study on the Communication Network of Wide Area Measurement System in Electricity Grid

NASA Astrophysics Data System (ADS)

Xiaorong, Cheng; Ying, Wang; Yangdan, Ni

Wide area measurement system(WAMS) is a fundamental part of security defense in Smart Grid, and the communication system of WAMS is an important part of Electric power communication network. For a large regional network is concerned, the real-time data which is transferred in the communication network of WAMS will affect the safe operation of the power grid directly. Therefore, WAMS raised higher requirements for real-time, reliability and security to its communication network. In this paper, the architecture of WASM communication network was studied according to the seven layers model of the open systems interconnection(OSI), and the network architecture was researched from all levels. We explored the media of WAMS communication network, the network communication protocol and network technology. Finally, the delay of the network were analyzed.

Synchronization stability and pattern selection in a memristive neuronal network.

PubMed

Wang, Chunni; Lv, Mi; Alsaedi, Ahmed; Ma, Jun

2017-11-01

Spatial pattern formation and selection depend on the intrinsic self-organization and cooperation between nodes in spatiotemporal systems. Based on a memory neuron model, a regular network with electromagnetic induction is proposed to investigate the synchronization and pattern selection. In our model, the memristor is used to bridge the coupling between the magnetic flux and the membrane potential, and the induction current results from the time-varying electromagnetic field contributed by the exchange of ion currents and the distribution of charged ions. The statistical factor of synchronization predicts the transition of synchronization and pattern stability. The bifurcation analysis of the sampled time series for the membrane potential reveals the mode transition in electrical activity and pattern selection. A formation mechanism is outlined to account for the emergence of target waves. Although an external stimulus is imposed on each neuron uniformly, the diversity in the magnetic flux and the induction current leads to emergence of target waves in the studied network.

Energy optimization for a wind DFIG with flywheel energy storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamzaoui, Ihssen, E-mail: hamzaoui-ihssen2000@yahoo.fr; Laboratory of Instrumentation, Faculty of Electronics and Computer, University of Khemis Miliana, Ain Defla; Bouchafaa, Farid, E-mail: fbouchafa@gmail.com

2016-07-25

The type of distributed generation unit that is the subject of this paper relates to renewable energy sources, especially wind power. The wind generator used is based on a double fed induction Generator (DFIG). The stator of the DFIG is connected directly to the network and the rotor is connected to the network through the power converter with three levels. The objective of this work is to study the association a Flywheel Energy Storage System (FESS) in wind generator. This system is used to improve the quality of electricity provided by wind generator. It is composed of a flywheel; anmore » induction machine (IM) and a power electronic converter. A maximum power tracking technique « Maximum Power Point Tracking » (MPPT) and a strategy for controlling the pitch angle is presented. The model of the complete system is developed in Matlab/Simulink environment / to analyze the results from simulation the integration of wind chain to networks.« less

Multi-time scale control of demand flexibility in smart distribution networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattarai, Bishnu; Myers, Kurt; Bak-Jensen, Birgitte

This study presents a multi-timescale control strategy to deploy demand flexibilities of electric vehicles (EV) for providing system balancing and local congestion management by simultaneously ensuring economic benefits to participating actors. First, the EV charging problem from consumer, aggregator, and grid operator’s perspective is investigated. A hierarchical control architecture (HCA) comprising scheduling, coordinative, and adaptive layers is then designed to realize their coordinative goal. This is realized by integrating a multi-time scale control, which works from a day-ahead scheduling up to real-time adaptive control. The performance of the developed method is investigated with high EV penetration in a typical distributionmore » network. The simulation results demonstrates that HCA exploit EV flexibility to solve grid unbalancing and congestions with simultaneous maximization of economic benefits by ensuring EV participation to day-ahead, balancing, and regulation markets. For the given network configuration and pricing structure, HCA ensures the EV owners to get paid up to 5 times the cost they were paying without control.« less

Multi-time scale control of demand flexibility in smart distribution networks

DOE PAGES

Bhattarai, Bishnu; Myers, Kurt; Bak-Jensen, Birgitte; ...

2017-01-01

This study presents a multi-timescale control strategy to deploy demand flexibilities of electric vehicles (EV) for providing system balancing and local congestion management by simultaneously ensuring economic benefits to participating actors. First, the EV charging problem from consumer, aggregator, and grid operator’s perspective is investigated. A hierarchical control architecture (HCA) comprising scheduling, coordinative, and adaptive layers is then designed to realize their coordinative goal. This is realized by integrating a multi-time scale control, which works from a day-ahead scheduling up to real-time adaptive control. The performance of the developed method is investigated with high EV penetration in a typical distributionmore » network. The simulation results demonstrates that HCA exploit EV flexibility to solve grid unbalancing and congestions with simultaneous maximization of economic benefits by ensuring EV participation to day-ahead, balancing, and regulation markets. For the given network configuration and pricing structure, HCA ensures the EV owners to get paid up to 5 times the cost they were paying without control.« less

Web-Enabled Optoelectronic Particle-Fallout Monitor

NASA Technical Reports Server (NTRS)

Lineberger, Lewis P.

2008-01-01

A Web-enabled optoelectronic particle- fallout monitor has been developed as a prototype of future such instruments that (l) would be installed in multiple locations for which assurance of cleanliness is required and (2) could be interrogated and controlled in nearly real time by multiple remote users. Like prior particle-fallout monitors, this instrument provides a measure of particles that accumulate on a surface as an indication of the quantity of airborne particulate contaminants. The design of this instrument reflects requirements to: Reduce the cost and complexity of its optoelectronic sensory subsystem relative to those of prior optoelectronic particle fallout monitors while maintaining or improving capabilities; Use existing network and office computers for distributed display and control; Derive electric power for the instrument from a computer network, a wall outlet, or a battery; Provide for Web-based retrieval and analysis of measurement data and of a file containing such ancillary data as a log of command attempts at remote units; and Use the User Datagram Protocol (UDP) for maximum performance and minimal network overhead.

Synchronization stability and pattern selection in a memristive neuronal network

NASA Astrophysics Data System (ADS)

Wang, Chunni; Lv, Mi; Alsaedi, Ahmed; Ma, Jun

2017-11-01

Spatial pattern formation and selection depend on the intrinsic self-organization and cooperation between nodes in spatiotemporal systems. Based on a memory neuron model, a regular network with electromagnetic induction is proposed to investigate the synchronization and pattern selection. In our model, the memristor is used to bridge the coupling between the magnetic flux and the membrane potential, and the induction current results from the time-varying electromagnetic field contributed by the exchange of ion currents and the distribution of charged ions. The statistical factor of synchronization predicts the transition of synchronization and pattern stability. The bifurcation analysis of the sampled time series for the membrane potential reveals the mode transition in electrical activity and pattern selection. A formation mechanism is outlined to account for the emergence of target waves. Although an external stimulus is imposed on each neuron uniformly, the diversity in the magnetic flux and the induction current leads to emergence of target waves in the studied network.

Mechanical and Electrical Characterization of Entangled Networks of Carbon Nanofibers

PubMed Central

Mousavi, Arash K.; Atwater, Mark A.; Mousavi, Behnam K.; Jalalpour, Mohammad; Taha, Mahmoud Reda; Leseman, Zayd C.

2014-01-01

Entangled networks of carbon nanofibers are characterized both mechanically and electrically. Results for both tensile and compressive loadings of the entangled networks are presented for various densities. Mechanically, the nanofiber ensembles follow the micromechanical model originally proposed by van Wyk nearly 70 years ago. Interpretations are given on the mechanisms occurring during loading and unloading of the carbon nanofiber components. PMID:28788709

The Effect of Plug-in Electric Vehicles on Harmonic Analysis of Smart Grid

NASA Astrophysics Data System (ADS)

Heidarian, T.; Joorabian, M.; Reza, A.

2015-12-01

In this paper, the effect of plug-in electric vehicles is studied on the smart distribution system with a standard IEEE 30-bus network. At first, harmonic power flow analysis is performed by Newton-Raphson method and by considering distorted substation voltage. Afterward, proper sizes of capacitors is selected by cuckoo optimization algorithm to reduce the power losses and cost and by imposing acceptable limit for total harmonic distortion and RMS voltages. It is proposed that the impact of generated current harmonics by electric vehicle battery chargers should be factored into overall load control strategies of smart appliances. This study is generalized to the different hours of a day by using daily load curve, and then optimum time for charging of electric vehicles batteries in the parking lots are determined by cuckoo optimization algorithm. The results show that injecting harmonic currents of plug-in electric vehicles causes a drop in the voltage profile and increases power loss. Moreover, charging the vehicle batteries has more impact on increasing the power losses rather than the harmonic currents effect. Also, the findings showed that the current harmonics has a great influence on increasing of THD. Finally, optimum working times of all parking lots was obtained for the utilization cost reduction.

Physical deposition behavior of stiff amphiphilic polyelectrolytes in an external electric field

NASA Astrophysics Data System (ADS)

Hu, Dongmei; Zuo, Chuncheng; Cao, Qianqian; Chen, Hongli

2017-08-01

Coarse-grained molecular dynamics simulations are conducted to study the physical deposition behavior of stiff amphiphilic polyelectrolytes (APEs) in an external electric field. The effects of chain stiffness, the charge distribution of a hydrophilic block, and electric field strength are investigated. Amphiphilic multilayers, which consist of a monolayer of adsorbed hydrophilic monomers (HLMs), a hydrophobic layer, and another hydrophilic layer, are formed in a selective solvent. All cases exhibit locally ordered hydrophilic monolayers. Two kinds of hydrophobic micelles are distinguished based on local structures. Stripe and network hydrophobic patterns are formed in individual cases. Increasing the chain stiffness decreases the thickness of the deposited layer, the lateral size of the hydrophobic micelles, and the amount of deposition. Increasing the number of positively charged HLMs in a single chain has the same effect as increasing chain stiffness. Moreover, when applied normally to the substrate, the electric field compresses the deposited structures and increases the amount of deposition by pulling more PEs toward the substrate. A stronger electric field also facilitates the formation of a thinner and more ordered hydrophilic adsorption layer. These estimates help us explore how to tailor patterned nano-surfaces, nano-interfaces, or amphiphilic nanostructures by physically depositing semi-flexible APEs which is of crucial importance in physical sciences, life sciences and nanotechnology.

Lightning protection of distribution systems

NASA Astrophysics Data System (ADS)

Darveniza, M.; Uman, M. A.

1982-09-01

Research work on the lightning protection of distribution systems is described. The rationale behind the planning of the first major phase of the work - the field experiments conducted in the Tampa Bay area during August 1978 and July to September 1979 is explained. The aims of the field work were to characterize lightning in the Tampa Bay area, and to identify the lightning parameters associated with the occurrence of line outages and equipment damage on the distribution systems of the participating utilities. The equipment developed for these studies is fully described. The field work provided: general data on lightning - e.g., electric and magnetic fields of cloud and ground flashes; data from automated monitoring of lightning activity; stroke current waveshapes and peak currents measured at distribution arresters; and line outage and equipment damage on 13 kV networks in the Tampa Bay area. Computer aided analyses were required to collate and to process the accumulated data. The computer programs developed for this work are described.

NREL Topic 1 Final Report: Cohesive Application of Standards-Based Connected Devices to Enable Clean Energy Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hudgins, Andrew P.; Sparn, Bethany F.; Jin, Xin

This document is the final report of a two-year development, test, and demonstration project entitled 'Cohesive Application of Standards-Based Connected Devices to Enable Clean Energy Technologies.' The project was part of the National Renewable Energy Laboratory's (NREL) Integrated Network Test-bed for Energy Grid Research and Technology (INTEGRATE) initiative. The Electric Power Research Institute (EPRI) and a team of partners were selected by NREL to carry out a project to develop and test how smart, connected consumer devices can act to enable the use of more clean energy technologies on the electric power grid. The project team includes a set ofmore » leading companies that produce key products in relation to achieving this vision: thermostats, water heaters, pool pumps, solar inverters, electric vehicle supply equipment, and battery storage systems. A key requirement of the project was open access at the device level - a feature seen as foundational to achieving a future of widespread distributed generation and storage. The internal intelligence, standard functionality and communication interfaces utilized in this project result in the ability to integrate devices at any level, to work collectively at the level of the home/business, microgrid, community, distribution circuit or other. Collectively, the set of products serve as a platform on which a wide range of control strategies may be developed and deployed.« less

A Computational Methodology to Support Reimbursement Requests Analysis Concerning Electrical Damages

NASA Astrophysics Data System (ADS)

Almeida Junior, Afonso Bernardino; Gondim, Isaque Nogueira; Rezende, Paulo Henrique Oliveira; Oliveira, José Carlos

2015-12-01

In light of the growing number of reimbursement requests processed from consumers for electrical damage to equipment, supposedly caused through the manifestation of anomalies on the power grid, there comes the need for reliable means for providing a decision on the issues highlighted herein. Through the recognition that in the current context, the procedures used are based on reviews, information and records of occurrences in the field, there has been significant inadequacy and fragility in the issuing of conclusive advice or opinions. In particular, the search for mechanisms grounded in classical principles and accepted in electrical engineering presents itself as an important challenge on which to base the decision making process in full awareness of its incumbent science and technology. Therefore, with the aim of meeting these assumptions, the study in question excels in its presentation of the principles that guided the software analysis, which intend above all else to correlate cause and effect. The elaborated strategy involves modelling stages as well as studies aimed at: distribution supply reproduction; characterization of the distribution network to the complainant consumer; representation of the diverse electro-electronic appliances and lastly, a proposal for correlating the disturbances impacting on equipment with their dielectric and thermal supportability requirements. For the purpose of illustrating the software process, an actual case study coupled with a loss and claim scenario is presented.

Electrical appliance energy consumption control methods and electrical energy consumption systems

DOEpatents

Donnelly, Matthew K [Kennewick, WA; Chassin, David P [Pasco, WA; Dagle, Jeffery E [Richland, WA; Kintner-Meyer, Michael [Richland, WA; Winiarski, David W [Kennewick, WA; Pratt, Robert G [Kennewick, WA; Boberly-Bartis, Anne Marie [Alexandria, VA

2006-03-07

Electrical appliance energy consumption control methods and electrical energy consumption systems are described. In one aspect, an electrical appliance energy consumption control method includes providing an electrical appliance coupled with a power distribution system, receiving electrical energy within the appliance from the power distribution system, consuming the received electrical energy using a plurality of loads of the appliance, monitoring electrical energy of the power distribution system, and adjusting an amount of consumption of the received electrical energy via one of the loads of the appliance from an initial level of consumption to an other level of consumption different than the initial level of consumption responsive to the monitoring.

Electrical appliance energy consumption control methods and electrical energy consumption systems

DOEpatents

Donnelly, Matthew K [Kennewick, WA; Chassin, David P [Pasco, WA; Dagle, Jeffery E [Richland, WA; Kintner-Meyer, Michael [Richland, WA; Winiarski, David W [Kennewick, WA; Pratt, Robert G [Kennewick, WA; Boberly-Bartis, Anne Marie [Alexandria, VA

2008-09-02

Electrical appliance energy consumption control methods and electrical energy consumption systems are described. In one aspect, an electrical appliance energy consumption control method includes providing an electrical appliance coupled with a power distribution system, receiving electrical energy within the appliance from the power distribution system, consuming the received electrical energy using a plurality of loads of the appliance, monitoring electrical energy of the power distribution system, and adjusting an amount of consumption of the received electrical energy via one of the loads of the appliance from an initial level of consumption to an other level of consumption different than the initial level of consumption responsive to the monitoring.

Studies of stimulus parameters for seizure disruption using neural network simulations.

PubMed

Anderson, William S; Kudela, Pawel; Cho, Jounhong; Bergey, Gregory K; Franaszczuk, Piotr J

2007-08-01

A large scale neural network simulation with realistic cortical architecture has been undertaken to investigate the effects of external electrical stimulation on the propagation and evolution of ongoing seizure activity. This is an effort to explore the parameter space of stimulation variables to uncover promising avenues of research for this therapeutic modality. The model consists of an approximately 800 mum x 800 mum region of simulated cortex, and includes seven neuron classes organized by cortical layer, inhibitory or excitatory properties, and electrophysiological characteristics. The cell dynamics are governed by a modified version of the Hodgkin-Huxley equations in single compartment format. Axonal connections are patterned after histological data and published models of local cortical wiring. Stimulation induced action potentials take place at the axon initial segments, according to threshold requirements on the applied electric field distribution. Stimulation induced action potentials in horizontal axonal branches are also separately simulated. The calculations are performed on a 16 node distributed 32-bit processor system. Clear differences in seizure evolution are presented for stimulated versus the undisturbed rhythmic activity. Data is provided for frequency dependent stimulation effects demonstrating a plateau effect of stimulation efficacy as the applied frequency is increased from 60 to 200 Hz. Timing of the stimulation with respect to the underlying rhythmic activity demonstrates a phase dependent sensitivity. Electrode height and position effects are also presented. Using a dipole stimulation electrode arrangement, clear orientation effects of the dipole with respect to the model connectivity is also demonstrated. A sensitivity analysis of these results as a function of the stimulation threshold is also provided.

Interface Control Document for the EMPACT Module that Estimates Electric Power Transmission System Response to EMP-Caused Damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Werley, Kenneth Alan; Mccown, Andrew William

The EPREP code is designed to evaluate the effects of an Electro-Magnetic Pulse (EMP) on the electric power transmission system. The EPREP code embodies an umbrella framework that allows a user to set up analysis conditions and to examine analysis results. The code links to three major physics/engineering modules. The first module describes the EM wave in space and time. The second module evaluates the damage caused by the wave on specific electric power (EP) transmission system components. The third module evaluates the consequence of the damaged network on its (reduced) ability to provide electric power to meet demand. Thismore » third module is the focus of the present paper. The EMPACT code serves as the third module. The EMPACT name denotes EMP effects on Alternating Current Transmission systems. The EMPACT algorithms compute electric power transmission network flow solutions under severely damaged network conditions. Initial solutions are often characterized by unacceptible network conditions including line overloads and bad voltages. The EMPACT code contains algorithms to adjust optimally network parameters to eliminate network problems while minimizing outages. System adjustments include automatically adjusting control equipment (generator V control, variable transformers, and variable shunts), as well as non-automatic control of generator power settings and minimal load shedding. The goal is to evaluate the minimal loss of customer load under equilibrium (steady-state) conditions during peak demand.« less

Electrical Resistivity Imaging Below Nuclear Waste Tank Farms at the Hanford Site

NASA Astrophysics Data System (ADS)

Rucker, D. F.; Levitt, M. T.

2006-12-01

The Hanford Site, a Department of Energy nuclear processing facility in eastern Washington, contains a complex series of radiological liquid waste disposal and storage facilities. The primary method of interim storage is the use of large single-shelled steel tanks with capacities of up to 3790 m3 (1 million gallons). The tanks are organized below ground into tank farms, with about 12 tanks per farm. The liquid waste within the tanks is primarily comprised of inorganic salts with minor constituents of heavy metals and radiological metals. The electrical properties of the radiological waste are significantly different to that of the surrounding engineered fill and native geologic formations. Over the past 60 years since the earliest tanks have been in use, many have been known to leak. An electrical resistivity survey was conducted within a tank farm to map the extent of the plumes resulting from historic leaks. Traditional surface-based electrical resistivity surveys resulted in unusable data due to the significant subsurface infrastructure that included a network of delivery pipes, wells, fences, and electrical discharge sources . HGI adapted the resistivity technique to include the site infrastructure as transceivers to augment data density and geometry. The results show a distribution of low resistivity values within the farm in areas that match known historic leak sites. The addition of site infrastructure as sensors demonstrates that the electrical resistivity technique can be used in highly industrial sites.

Design of the smart home system based on the optimal routing algorithm and ZigBee network.

PubMed

Jiang, Dengying; Yu, Ling; Wang, Fei; Xie, Xiaoxia; Yu, Yongsheng

2017-01-01

To improve the traditional smart home system, its electric wiring, networking technology, information transmission and facility control are studied. In this paper, we study the electric wiring, networking technology, information transmission and facility control to improve the traditional smart home system. First, ZigBee is used to replace the traditional electric wiring. Second, a network is built to connect lots of wireless sensors and facilities, thanks to the capability of ZigBee self-organized network and Genetic Algorithm-Particle Swarm Optimization Algorithm (GA-PSOA) to search for the optimal route. Finally, when the smart home system is connected to the internet based on the remote server technology, home environment and facilities could be remote real-time controlled. The experiments show that the GA-PSOA reduce the system delay and decrease the energy consumption of the wireless system.

Design of the smart home system based on the optimal routing algorithm and ZigBee network

PubMed Central

Xie, Xiaoxia

2017-01-01

To improve the traditional smart home system, its electric wiring, networking technology, information transmission and facility control are studied. In this paper, we study the electric wiring, networking technology, information transmission and facility control to improve the traditional smart home system. First, ZigBee is used to replace the traditional electric wiring. Second, a network is built to connect lots of wireless sensors and facilities, thanks to the capability of ZigBee self-organized network and Genetic Algorithm-Particle Swarm Optimization Algorithm (GA-PSOA) to search for the optimal route. Finally, when the smart home system is connected to the internet based on the remote server technology, home environment and facilities could be remote real-time controlled. The experiments show that the GA-PSOA reduce the system delay and decrease the energy consumption of the wireless system. PMID:29131868

A strip chart recorder pattern recognition tool kit for Shuttle operations

NASA Technical Reports Server (NTRS)

Hammen, David G.; Moebes, Travis A.; Shelton, Robert O.; Savely, Robert T.

1993-01-01

During Space Shuttle operations, Mission Control personnel monitor numerous mission-critical systems such as electrical power; guidance, navigation, and control; and propulsion by means of paper strip chart recorders. For example, electrical power controllers monitor strip chart recorder pen traces to identify onboard electrical equipment activations and deactivations. Recent developments in pattern recognition technologies coupled with new capabilities that distribute real-time Shuttle telemetry data to engineering workstations make it possible to develop computer applications that perform some of the low-level monitoring now performed by controllers. The number of opportunities for such applications suggests a need to build a pattern recognition tool kit to reduce software development effort through software reuse. We are building pattern recognition applications while keeping such a tool kit in mind. We demonstrated the initial prototype application, which identifies electrical equipment activations, during three recent Shuttle flights. This prototype was developed to test the viability of the basic system architecture, to evaluate the performance of several pattern recognition techniques including those based on cross-correlation, neural networks, and statistical methods, to understand the interplay between an advanced automation application and human controllers to enhance utility, and to identify capabilities needed in a more general-purpose tool kit.

Distributed charging of electrical assets

DOEpatents

Ghosh, Soumyadip; Phan, Dung; Sharma, Mayank; Wu, Chai Wah; Xiong, Jinjun

2016-02-16

The present disclosure relates generally to the field of distributed charging of electrical assets. In various examples, distributed charging of electrical assets may be implemented in the form of systems, methods and/or algorithms.

Decompositions of injection patterns for nodal flow allocation in renewable electricity networks

NASA Astrophysics Data System (ADS)

Schäfer, Mirko; Tranberg, Bo; Hempel, Sabrina; Schramm, Stefan; Greiner, Martin

2017-08-01

The large-scale integration of fluctuating renewable power generation represents a challenge to the technical and economical design of a sustainable future electricity system. In this context, the increasing significance of long-range power transmission calls for innovative methods to understand the emerging complex flow patterns and to integrate price signals about the respective infrastructure needs into the energy market design. We introduce a decomposition method of injection patterns. Contrary to standard flow tracing approaches, it provides nodal allocations of link flows and costs in electricity networks by decomposing the network injection pattern into market-inspired elementary import/export building blocks. We apply the new approach to a simplified data-driven model of a European electricity grid with a high share of renewable wind and solar power generation.

Synchronization of Lienard-Type Oscillators in Uniform Electrical Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinha, Mohit; Dorfler, Florian; Johnson, Brian B.

2016-08-01

This paper presents a condition for global asymptotic synchronization of Lienard-type nonlinear oscillators in uniform LTI electrical networks with series R-L circuits modeling interconnections. By uniform electrical networks, we mean that the per-unit-length impedances are identical for the interconnecting lines. We derive conditions for global asymptotic synchronization for a particular feedback architecture where the derivative of the oscillator output current supplements the innate current feedback induced by simply interconnecting the oscillator to the network. Our proof leverages a coordinate transformation to a set of differential coordinates that emphasizes signal differences and the particular form of feedback permits the formulation ofmore » a quadratic Lyapunov function for this class of networks. This approach is particularly interesting since synchronization conditions are difficult to obtain by means of quadratic Lyapunov functions when only current feedback is used and for networks composed of series R-L circuits. Our synchronization condition depends on the algebraic connectivity of the underlying network, and reiterates the conventional wisdom from Lyapunov- and passivity-based arguments that strong coupling is required to ensure synchronization.« less

Three essays on "making" electric power markets

NASA Astrophysics Data System (ADS)

Kench, Brian Thomas

2000-10-01

Technological change over the past three decades has altered most of the basic conditions in the electric power industry. Because of technical progress, the dominant paradigm has shifted from the provision of electric power by regulated and vertically integrated local natural monopolies to competition and vertical separation. In the first essay I provide a historical context of the electric industry's power current deregulation debate. Then a dynamic model of induced institutional change is used to investigate how endogenous technological advancements have induced radical institutional change in the generation and transmission segments of the electric power industry. Because the Federal Energy Regulatory Commission (FERC) ordered regulated utilities to provide open access to their transmission networks and to separate their generation and transmission functions, transmission networks have been used more intensively and in much different ways then in the past. The second essay tests experimentally the predictions of neoclassical theory for a radial electric power market under two alternative deregulated transmission institutions: financial transmission rights and physical transmission rights. Experimental evidence presented there demonstrates that an electric power market with physical transmission rights governing its transmission network generates more "right" market signals relative to a transmission network governed by financial transmission rights. The move to a greater reliance on markets for electric power is an idea that has animated sweeping and dramatic changes in the traditional business of electric power. The third essay examines two of the most innovative and complex initiatives of making electric power markets in the United States: California and PJM. As those markets mature and others are made, they must revise their governance mechanisms to eliminate rules that create inefficiency and adopt rules that work efficiently elsewhere. I argue that restructured electric power markets in the United States we should consider adopting an integrated procurement approach for electric power and ancillary services, binding forward markets for those commodities, and a market for physical transmission rights.

Electricity storage: Friend or foe of the networks?

NASA Astrophysics Data System (ADS)

Jamasb, Tooraj

2017-06-01

As storage technology progresses it offers a range of solutions and services to users and the electricity industry. A new study explores whether or not this will eventually lead to self-sufficient consumers and spell the end of the networks as we know them.

A Taxonomy of Attacks on the DNP3 Protocol

NASA Astrophysics Data System (ADS)

East, Samuel; Butts, Jonathan; Papa, Mauricio; Shenoi, Sujeet

Distributed Network Protocol (DNP3) is the predominant SCADA protocol in the energy sector - more than 75% of North American electric utilities currently use DNP3 for industrial control applications. This paper presents a taxonomy of attacks on the protocol. The attacks are classified based on targets (control center, outstation devices and network/communication paths) and threat categories (interception, interruption, modification and fabrication). To facilitate risk analysis and mitigation strategies, the attacks are associated with the specific DNP3 protocol layers they exploit. Also, the operational impact of the attacks is categorized in terms of three key SCADA objectives: process confi- dentiality, process awareness and process control. The attack taxonomy clarifies the nature and scope of the threats to DNP3 systems, and can provide insights into the relative costs and benefits of implementing mitigation strategies.

Ensuring sustainability of non-networked sanitation technologies: an approach to standardization.

PubMed

Starkl, Markus; Brunner, Norbert; Feil, Magdalena; Hauser, Andreas

2015-06-02

Non-networked sanitation technologies use no sewer, water or electricity lines. Based on a review of 45 commercially distributed technologies, 12 (representing three concepts) were selected for a detailed audit. They were located in six countries of Africa and Asia. The safety of users was generally assured and the costs per use were not excessive, whereas costs were fully transparent for only one technology surveyed. A main drawback was insufficient quality of the byproducts from on-site treatment, making recycling in agriculture a hygienic and environmental risk. Further, no technology was sufficiently mature (requiring e.g. to shift wastes by hand). In order to promote further development and give producers of mature products a competitive advantage, the paper proposes a certification of technologies to confirm the fulfillment of basic requirements to make them attractive for future users.

Cybersecurity Intrusion Detection and Monitoring for Field Area Network: Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pietrowicz, Stanley

This report summarizes the key technical accomplishments, industry impact and performance of the I2-CEDS grant entitled “Cybersecurity Intrusion Detection and Monitoring for Field Area Network”. Led by Applied Communication Sciences (ACS/Vencore Labs) in conjunction with its utility partner Sacramento Municipal Utility District (SMUD), the project accelerated research on a first-of-its-kind cybersecurity monitoring solution for Advanced Meter Infrastructure and Distribution Automation field networks. It advanced the technology to a validated, full-scale solution that detects anomalies, intrusion events and improves utility situational awareness and visibility. The solution was successfully transitioned and commercialized for production use as SecureSmart™ Continuous Monitoring. Discoveries made withmore » SecureSmart™ Continuous Monitoring led to tangible and demonstrable improvements in the security posture of the US national electric infrastructure.« less

Neural network control of a parallel hybrid-electric propulsion system for a small unmanned aerial vehicle

NASA Astrophysics Data System (ADS)

Harmon, Frederick G.

2005-11-01

Parallel hybrid-electric propulsion systems would be beneficial for small unmanned aerial vehicles (UAVs) used for military, homeland security, and disaster-monitoring missions. The benefits, due to the hybrid and electric-only modes, include increased time-on-station and greater range as compared to electric-powered UAVs and stealth modes not available with gasoline-powered UAVs. This dissertation contributes to the research fields of small unmanned aerial vehicles, hybrid-electric propulsion system control, and intelligent control. A conceptual design of a small UAV with a parallel hybrid-electric propulsion system is provided. The UAV is intended for intelligence, surveillance, and reconnaissance (ISR) missions. A conceptual design reveals the trade-offs that must be considered to take advantage of the hybrid-electric propulsion system. The resulting hybrid-electric propulsion system is a two-point design that includes an engine primarily sized for cruise speed and an electric motor and battery pack that are primarily sized for a slower endurance speed. The electric motor provides additional power for take-off, climbing, and acceleration and also serves as a generator during charge-sustaining operation or regeneration. The intelligent control of the hybrid-electric propulsion system is based on an instantaneous optimization algorithm that generates a hyper-plane from the nonlinear efficiency maps for the internal combustion engine, electric motor, and lithium-ion battery pack. The hyper-plane incorporates charge-depletion and charge-sustaining strategies. The optimization algorithm is flexible and allows the operator/user to assign relative importance between the use of gasoline, electricity, and recharging depending on the intended mission. A MATLAB/Simulink model was developed to test the control algorithms. The Cerebellar Model Arithmetic Computer (CMAC) associative memory neural network is applied to the control of the UAVs parallel hybrid-electric propulsion system. The CMAC neural network approximates the hyper-plane generated from the instantaneous optimization algorithm and produces torque commands for the internal combustion engine and electric motor. The CMAC neural network controller saves on the required memory as compared to a large look-up table by two orders of magnitude. The CMAC controller also prevents the need to compute a hyper-plane or complex logic every time step.

Diagnosis and Reconfiguration using Bayesian Networks: An Electrical Power System Case Study

NASA Technical Reports Server (NTRS)

Knox, W. Bradley; Mengshoel, Ole

2009-01-01

Automated diagnosis and reconfiguration are important computational techniques that aim to minimize human intervention in autonomous systems. In this paper, we develop novel techniques and models in the context of diagnosis and reconfiguration reasoning using causal Bayesian networks (BNs). We take as starting point a successful diagnostic approach, using a static BN developed for a real-world electrical power system. We discuss in this paper the extension of this diagnostic approach along two dimensions, namely: (i) from a static BN to a dynamic BN; and (ii) from a diagnostic task to a reconfiguration task. More specifically, we discuss the auto-generation of a dynamic Bayesian network from a static Bayesian network. In addition, we discuss subtle, but important, differences between Bayesian networks when used for diagnosis versus reconfiguration. We discuss a novel reconfiguration agent, which models a system causally, including effects of actions through time, using a dynamic Bayesian network. Though the techniques we discuss are general, we demonstrate them in the context of electrical power systems (EPSs) for aircraft and spacecraft. EPSs are vital subsystems on-board aircraft and spacecraft, and many incidents and accidents of these vehicles have been attributed to EPS failures. We discuss a case study that provides initial but promising results for our approach in the setting of electrical power systems.

Effects of length dispersity and film fabrication on the sheet resistance of copper nanowire transparent conductors

NASA Astrophysics Data System (ADS)

Borchert, James W.; Stewart, Ian E.; Ye, Shengrong; Rathmell, Aaron R.; Wiley, Benjamin J.; Winey, Karen I.

2015-08-01

Development of thin-film transparent conductors (TC) based on percolating networks of metal nanowires has leaped forward in recent years, owing to the improvement of nanowire synthetic methods and modeling efforts by several research groups. While silver nanowires are the first commercially viable iteration of this technology, systems based on copper nanowires are not far behind. Here we present an analysis of TCs composed of copper nanowire networks on sheets of polyethylene terephthalate that have been treated with various oxide-removing post treatments to improve conductivity. A pseudo-2D rod network modeling approach has been modified to include lognormal distributions in length that more closely reflect experimental data collected from the nanowire TCs. In our analysis, we find that the copper nanowire TCs are capable of achieving comparable electrical performance to silver nanowire TCs with similar dimensions. Lastly, we present a method for more accurately determining the nanowire area coverage in a TC over a large area using Rutherford Backscattering Spectrometry (RBS) to directly measure the metal content in the TCs. These developments will aid research and industry groups alike in the characterization of nanowire based TCs.Development of thin-film transparent conductors (TC) based on percolating networks of metal nanowires has leaped forward in recent years, owing to the improvement of nanowire synthetic methods and modeling efforts by several research groups. While silver nanowires are the first commercially viable iteration of this technology, systems based on copper nanowires are not far behind. Here we present an analysis of TCs composed of copper nanowire networks on sheets of polyethylene terephthalate that have been treated with various oxide-removing post treatments to improve conductivity. A pseudo-2D rod network modeling approach has been modified to include lognormal distributions in length that more closely reflect experimental data collected from the nanowire TCs. In our analysis, we find that the copper nanowire TCs are capable of achieving comparable electrical performance to silver nanowire TCs with similar dimensions. Lastly, we present a method for more accurately determining the nanowire area coverage in a TC over a large area using Rutherford Backscattering Spectrometry (RBS) to directly measure the metal content in the TCs. These developments will aid research and industry groups alike in the characterization of nanowire based TCs. Electronic supplementary information (ESI) available: Contains calibration curve for %T vs. area fraction. See DOI: 10.1039/c5nr03671b

Energy-aware virtual network embedding in flexi-grid networks.

PubMed

Lin, Rongping; Luo, Shan; Wang, Haoran; Wang, Sheng

2017-11-27

Network virtualization technology has been proposed to allow multiple heterogeneous virtual networks (VNs) to coexist on a shared substrate network, which increases the utilization of the substrate network. Efficiently mapping VNs on the substrate network is a major challenge on account of the VN embedding (VNE) problem. Meanwhile, energy efficiency has been widely considered in the network design in terms of operation expenses and the ecological awareness. In this paper, we aim to solve the energy-aware VNE problem in flexi-grid optical networks. We provide an integer linear programming (ILP) formulation to minimize the electricity cost of each arriving VN request. We also propose a polynomial-time heuristic algorithm where virtual links are embedded sequentially to keep a reasonable acceptance ratio and maintain a low electricity cost. Numerical results show that the heuristic algorithm performs closely to the ILP for a small size network, and we also demonstrate its applicability to larger networks.

Self-organized topology of recurrence-based complex networks

NASA Astrophysics Data System (ADS)

Yang, Hui; Liu, Gang

2013-12-01

With the rapid technological advancement, network is almost everywhere in our daily life. Network theory leads to a new way to investigate the dynamics of complex systems. As a result, many methods are proposed to construct a network from nonlinear time series, including the partition of state space, visibility graph, nearest neighbors, and recurrence approaches. However, most previous works focus on deriving the adjacency matrix to represent the complex network and extract new network-theoretic measures. Although the adjacency matrix provides connectivity information of nodes and edges, the network geometry can take variable forms. The research objective of this article is to develop a self-organizing approach to derive the steady geometric structure of a network from the adjacency matrix. We simulate the recurrence network as a physical system by treating the edges as springs and the nodes as electrically charged particles. Then, force-directed algorithms are developed to automatically organize the network geometry by minimizing the system energy. Further, a set of experiments were designed to investigate important factors (i.e., dynamical systems, network construction methods, force-model parameter, nonhomogeneous distribution) affecting this self-organizing process. Interestingly, experimental results show that the self-organized geometry recovers the attractor of a dynamical system that produced the adjacency matrix. This research addresses a question, i.e., "what is the self-organizing geometry of a recurrence network?" and provides a new way to reproduce the attractor or time series from the recurrence plot. As a result, novel network-theoretic measures (e.g., average path length and proximity ratio) can be achieved based on actual node-to-node distances in the self-organized network topology. The paper brings the physical models into the recurrence analysis and discloses the spatial geometry of recurrence networks.

Self-organized topology of recurrence-based complex networks.

PubMed

Yang, Hui; Liu, Gang

2013-12-01

With the rapid technological advancement, network is almost everywhere in our daily life. Network theory leads to a new way to investigate the dynamics of complex systems. As a result, many methods are proposed to construct a network from nonlinear time series, including the partition of state space, visibility graph, nearest neighbors, and recurrence approaches. However, most previous works focus on deriving the adjacency matrix to represent the complex network and extract new network-theoretic measures. Although the adjacency matrix provides connectivity information of nodes and edges, the network geometry can take variable forms. The research objective of this article is to develop a self-organizing approach to derive the steady geometric structure of a network from the adjacency matrix. We simulate the recurrence network as a physical system by treating the edges as springs and the nodes as electrically charged particles. Then, force-directed algorithms are developed to automatically organize the network geometry by minimizing the system energy. Further, a set of experiments were designed to investigate important factors (i.e., dynamical systems, network construction methods, force-model parameter, nonhomogeneous distribution) affecting this self-organizing process. Interestingly, experimental results show that the self-organized geometry recovers the attractor of a dynamical system that produced the adjacency matrix. This research addresses a question, i.e., "what is the self-organizing geometry of a recurrence network?" and provides a new way to reproduce the attractor or time series from the recurrence plot. As a result, novel network-theoretic measures (e.g., average path length and proximity ratio) can be achieved based on actual node-to-node distances in the self-organized network topology. The paper brings the physical models into the recurrence analysis and discloses the spatial geometry of recurrence networks.

Self-organized topology of recurrence-based complex networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Hui, E-mail: huiyang@usf.edu; Liu, Gang

With the rapid technological advancement, network is almost everywhere in our daily life. Network theory leads to a new way to investigate the dynamics of complex systems. As a result, many methods are proposed to construct a network from nonlinear time series, including the partition of state space, visibility graph, nearest neighbors, and recurrence approaches. However, most previous works focus on deriving the adjacency matrix to represent the complex network and extract new network-theoretic measures. Although the adjacency matrix provides connectivity information of nodes and edges, the network geometry can take variable forms. The research objective of this article ismore » to develop a self-organizing approach to derive the steady geometric structure of a network from the adjacency matrix. We simulate the recurrence network as a physical system by treating the edges as springs and the nodes as electrically charged particles. Then, force-directed algorithms are developed to automatically organize the network geometry by minimizing the system energy. Further, a set of experiments were designed to investigate important factors (i.e., dynamical systems, network construction methods, force-model parameter, nonhomogeneous distribution) affecting this self-organizing process. Interestingly, experimental results show that the self-organized geometry recovers the attractor of a dynamical system that produced the adjacency matrix. This research addresses a question, i.e., “what is the self-organizing geometry of a recurrence network?” and provides a new way to reproduce the attractor or time series from the recurrence plot. As a result, novel network-theoretic measures (e.g., average path length and proximity ratio) can be achieved based on actual node-to-node distances in the self-organized network topology. The paper brings the physical models into the recurrence analysis and discloses the spatial geometry of recurrence networks.« less

Relationship between inter-stimulus-intervals and intervals of autonomous activities in a neuronal network.

PubMed

Ito, Hidekatsu; Minoshima, Wataru; Kudoh, Suguru N

2015-08-01

To investigate relationships between neuronal network activity and electrical stimulus, we analyzed autonomous activity before and after electrical stimulus. Recordings of autonomous activity were performed using dissociated culture of rat hippocampal neurons on a multi-electrodes array (MEA) dish. Single stimulus and pared stimuli were applied to a cultured neuronal network. Single stimulus was applied every 1 min, and paired stimuli was performed by two sequential stimuli every 1 min. As a result, the patterns of synchronized activities of a neuronal network were changed after stimulus. Especially, long range synchronous activities were induced by paired stimuli. When 1 s inter-stimulus-intervals (ISI) and 1.5 s ISI paired stimuli are applied to a neuronal network, relatively long range synchronous activities expressed in case of 1.5 s ISI. Temporal synchronous activity of neuronal network is changed according to inter-stimulus-intervals (ISI) of electrical stimulus. In other words, dissociated neuronal network can maintain given information in temporal pattern and a certain type of an information maintenance mechanism was considered to be implemented in a semi-artificial dissociated neuronal network. The result is useful toward manipulation technology of neuronal activity in a brain system.

ELECTRIC VEHICLE CONVERSIONS USING ALTERNATIVE ENERGY TO DRIVE ALASKAN RURAL COMMUNITIES

EPA Science Inventory

This proposal concerns sustainable transportation in rural Alaskan communities which are not part of a road or electrical network (off grid). In most off-grid communities, the road networks generally are less than 50 square miles, so transportation needs are limited. This limi...