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1

MPPT Battery Charger for Stand-Alone Wind Power System  

Microsoft Academic Search

In this paper, a buck-type power converter as the bat- tery charger for the stand-alone wind power system is proposed. The proposed power converter can harvest the maximum power from the wind turbine while generating pulsating current for the battery bank to improve the charging efficiency. The maximum power point tracking function is realized by the constant on-time control, the

Kuo-Yuan Lo; Yaow-Ming Chen; Yung-Ruei Chang

2011-01-01

2

Hybrid powering system for stand-alone remote telecom applications  

Microsoft Academic Search

This paper presents the analysis of a hybrid power system (HPS) based on photovoltaic, battery and liquefied petroleum gas genset (PV\\/BAT\\/LPG) in remote telecommunications equipment of low power. From the various forms of supplying such equipment not connected to the public grid, a solution is proposed that combines three sources (one of them renewable energy), providing redundancy. It is procured

Vicente Salas; Emilio Olias; M. Rascon; M. Vazquez; C. Quifiones

2000-01-01

3

Neural-Network-Based MPPT Control of a Stand-Alone Hybrid Power Generation System  

Microsoft Academic Search

A stand-alone hybrid power system is proposed in this paper. The system consists of solar power, wind power, diesel engine, and an intelligent power controller. MATLAB\\/Simulink was used to build the dynamic model and simulate the system. To achieve a fast and stable response for the real power control, the intelligent controller consists of a radial basis function network (RBFN)

Whei-Min Lin; Chih-Ming Hong; Chiung-Hsing Chen

2011-01-01

4

A systems approach for sizing a stand-alone residential PEMFC power system  

Microsoft Academic Search

Polymer electrolyte membrane fuel cells (PEMFCs) show great promise in portable, automotive, and stationary applications. They have reached the test and demonstration phase in automotive and power markets today. This paper is focused on a stand-alone residential PEMFC power system that provides the electricity needs of the house. A novel stochastic sizing methodology is developed that considers both fuel cell

U?ur S. Selamo?ullar?; Thomas R. Willemain; David A. Torrey

2007-01-01

5

Economic evaluation of a stand-alone residential photovoltaic power system in Bangladesh  

Microsoft Academic Search

The economics of stand-alone photovoltaic power system is studied to test its feasibility in remote and rural areas of Bangladesh and to compare renewable generators with non-renewable generators. The life cycle cost of these generators are determined using the method of net present value analysis. It is found that the life cycle cost of this experimental PV system is Tk.

M. M. H Bhuiyan; M. Ali Asgar; R. K Mazumder; M Hussain

2000-01-01

6

A Novel Maximum Power Point Tracking Strategy for Stand-alone Solar Pumping Systems  

Microsoft Academic Search

A novel hybrid maximum power point tracking (MPPT) control strategy for stand-alone solar pumping systems without backup batteries is proposed in this paper. The whole control process consists of two steps: the judgment of speed up or down and the selection of step size of speed command. Basically, the system with the proposed MPPT strategy is controlled by a normal

Guo Heng; Xu Zheng; Li You-Chun; Wang Hui

2005-01-01

7

Novel Power Control Scheme for Stand-Alone Photovoltaic Generation System  

Microsoft Academic Search

This study mainly develops a novel power control scheme for a stand-alone photovoltaic (PV) generation system. In order to make the PV generation system more flexibility and expandability, the later power circuit is composed of a high step-up converter and a pulse-width-modulation (PWM) inverter. In the DC-DC power conversion, the high step-up converter is introduced to improve the conversion efficiency

Rong-Jong Wai; Chung-You Lin; Wen-Hung Wang

2006-01-01

8

Loss of power supply probability of stand-alone photovoltaic systems: a closed form solution approach  

Microsoft Academic Search

A closed-form solution approach to the evaluation of the loss of power supply probability of stand-alone photovoltaic system with energy storage is presented. Nontracking and single-axis tracking systems are considered. In both cases, the tilt is assumed to be fixed. A numerical example is included to illustrate the usefulness of the expressions developed. Relationships between the amount of energy storage

Imad Abouzahr; R. Ramakumar

1991-01-01

9

Why are remote Western Australians installing renewable energy technologies in stand-alone power supply systems?  

Microsoft Academic Search

As people living in remote areas rely on SPS systems for their electricity and water needs, they hold a practical and non-idealistic perspective towards using renewable energy technologies. This research explores pastoral owner-operators’ personal experience and opinion of stand-alone power supply (SPS) systems over 30years in remote pastoral regions Western Australia (WA). This research was undertaken qualitatively in terms of

Mark P. McHenry

2009-01-01

10

A Control Method for Maximum Power Point Tracking in Stand-Alone-Type PV Generation Systems  

NASA Astrophysics Data System (ADS)

In this paper, a new control method for maximum power point tracking (MPPT) in stand-alone-type PV generaton systems is proposed. In this control method, the operations detecting the maximum power point and tracking its point are alternately carried out by using a step-up DC—DC converter. This method requires neither the measurement of temperature and insolation level nor PV array model. In a stand-alone-type application with a battery load, the design method for the boost inductance L of the step-up DC—DC converter is described, and the experimental results show that the use of the proposed MPPT control increases the PV generated energy by 14.8% compared to the conventional system.

Itako, Kazutaka; Mori, Takeaki

11

Estimating loss-of-power probabilities of stand-alone photovoltaic solar energy systems  

Microsoft Academic Search

This paper describes an approximate approach to evaluating the performance, including the probability of loss-of-power (or loss-of-load, as some would have it) of stand-alone photovoltaic solar energy systems. The method treats the energy capture, storage and disbursement process as a random walk in the storage domain. To apply the technique, one must know the variance, as well as the mean,

L. L. Bucciarelli Jr.

1984-01-01

12

A Novel Method for Improving Overload Capability of Stand-alone Power System Based on a Flywheel Induction Motor  

NASA Astrophysics Data System (ADS)

Stand-alone power systems are widely used in islands and remote areas. With the rapid advances in the new energy technology, stand-alone power systems have got a rapid development. However, their overload capability is very poor. In this paper, a novel method to improve the overload performance of the stand-alone power system is proposed by using a flywheel induction motor. The flywheel induction motor is composed of a flywheel disk connected to a squirrel cage induction motor. It is controlled to supply the overload power of the stand-alone power supply by charging and discharging. The proposed system is characterized by the following three points: 1) Simple configuration; The flywheel induction motor is directly connected to the inverter-controlled load without any converters. 2) Simple frequency control; The expected active power flow is realized by a small change of the stand-alone power side inverter's output frequency. 3) Low cost system; A decreased power capacity demand for the stand-alone power supply is realized by adding a low cost flywheel induction motor. Experimental results are provided to verify the proposed system.

Cheng, Miao-Miao; Kato, Shuhei; Sumitani, Hideo; Shimada, Ryuichi

13

Design Optimization and Dynamic Performance Analysis of a Stand-Alone Hybrid Wind–Diesel Electrical Power Generation System  

Microsoft Academic Search

An algorithm for optimal sizing of all the components of a stand-alone hybrid wind-diesel electrical power generation system, in the sense of minimum energy cost is reported in this paper. The total system reactive power balance condition, which is not often considered for designing stand-alone systems, is included with others in the nonlinear constrained optimization technique employed to maximize the

Tapas Kumar Saha; Debaprasad Kastha

2010-01-01

14

Power control of a stand-alone photovoltaic\\/ wind\\/ energy storage hybrid generation system with Maximum Power Point Tracker  

Microsoft Academic Search

In this paper, a hybrid generation system combining photovoltaic (PV), wind turbine (WT) and Electric Double Layer Capacitor (EDLC) is presented to supply stable power to residential power applications as stand-alone loads. The photovoltaic and wind systems are used as main energy sources while the EDLC is used as storage device. Three individual DC\\/DC converters are used to control the

Yukihiro Ozaki; Masafumi Miyatake; Daisuke Iwaki

2010-01-01

15

Solar photovoltaic applications seminar: design, installation and operation of small, stand-alone photovoltaic power systems  

SciTech Connect

This seminar material was developed primarily to provide solar photovoltaic (PV) applied engineering technology to the Federal community. An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. The seminar details general systems design and incorporates most known information from industry, academia, and Government concerning small solar cell power system design engineering, presented in a practical and applied manner. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping, domestic uses, navigational and aircraft aids, and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand-alone systems to be used in remote locations. Also presented are practical lessons gained from currently installed and operating systems, problems at sites and their resolution, a logical progression through each major phase of system acquisition, as well as thorough design reviews for each application.

Not Available

1980-07-01

16

A stand-alone photovoltaic power system for remote villages using pumped water energy storage  

Microsoft Academic Search

The present paper regards the implementation of a stand-alone photovoltaic plant in which battery storage is partially replaced by a micro-hydraulic system. The plant was installed on Donoussa Island in the Aegean Sea, Greece to cover basic electricity needs of the remote village of Merssini (13 houses). Lighting, TV set and refrigerator were considered basic electricity needs for each house.

D. Manolakos; G. Papadakis; D. Papantonis; S. Kyritsis

2004-01-01

17

Power management of a stand-alone hybrid wind-microturbine distributed generation system  

Microsoft Academic Search

As generation and transmission costs, system stability, and security issues continue to be complicated by growing electricity demand that relies primarily on centralized electricity production, alternative distributed generation (DG) systems show promise as a solution. This paper presents a hybrid wind-microturbine generation (MTG) system for stand-alone applications. The Wind-MTG hybrid mainly consists of a wind energy conversion system that utilizes

Caisheng Wang; C. M. Colson; M. H. Nehrir; Jian Li

2009-01-01

18

Performance Analysis of Optimally Operated DOIG Based Stand-Alone Wind Power Generation System at Different Sites  

Microsoft Academic Search

An algorithm is developed for optimal sizing of wind driven stand-alone double output induction generator (DOIG). Nonlinear constrained optimization technique is used to trace the maximum power generated by the system for a given machine and converter rating. Both inequality and equality nonlinear constraints are considered. Among them the most significant one is the reactive power balance constraints, which is

T. K. Saha; Debaprasad Kastha

2006-01-01

19

Economic viability of stand-alone solar photovoltaic system in comparison with diesel-powered system for India  

Microsoft Academic Search

The economic viability of a stand-alone solar photovoltaic (PV) system with the most likely conventional alternative system, i.e. a diesel-powered system, has been analysed for energy demand through sensitivity analysis using a life-cycle cost computation. The sensitivity analysis allows estimation of the comparative viability of PV against a conventional alternative system based on particular country-specific parameters. The overall PV best

Mohanlal Kolhe; Sunita Kolhe; J. C. Joshi

2002-01-01

20

Current status of research on optimum sizing of stand-alone hybrid solar–wind power generation systems  

Microsoft Academic Search

Solar and wind energy systems are omnipresent, freely available, environmental friendly, and they are considered as promising power generating sources due to their availability and topological advantages for local power generations. Hybrid solar–wind energy systems, uses two renewable energy sources, allow improving the system efficiency and power reliability and reduce the energy storage requirements for stand-alone applications. The hybrid solar–wind

Wei Zhou; Chengzhi Lou; Zhongshi Li; Lin Lu; Hongxing Yang

2010-01-01

21

An Integrated Feasibility Analysis of a Stand-alone Wind Power System, including No-energy Fulfillment Cost  

Microsoft Academic Search

Autonomous wind power systems are among the most interesting and environmentally friendly technological solutions for the electrification of remote consumers. However, the expected system operational cost is quite high, especially if the no-load rejection restriction is applied. This article describes an integrated feasibility analysis of a stand-alone wind power system, considering, beyond the total long-term operational cost of the system,

J. K. Kaldellis

2003-01-01

22

Power fluctuations suppression of stand-alone hybrid generation combining solar photovoltaic\\/wind turbine and fuel cell systems  

Microsoft Academic Search

In this paper a hybrid energy system combining variable speed wind turbine, solar photovoltaic and fuel cell generation systems is presented to supply continuous power to residential power applications as stand-alone loads. The wind and photovoltaic systems are used as main energy sources while the fuel cell is used as secondary or back-up energy source. Three individual dc–dc boost converters

Nabil A. Ahmed; Masafumi Miyatake; A. K. Al-Othman

2008-01-01

23

Loss of power supply probability of stand-alone wind electric conversion systems: a closed form solution approach  

Microsoft Academic Search

A closed-form solution approach to evaluating the loss of power supply probability for stand-alone wind-electric conversion systems with energy storage is presented. A numerical example is included to illustrate the usefulness of the expressions developed. In particular, the results allow investigation of the relationship between the amount of energy storage and the loss of power supply probability under various operating

Imad Abouzahr; R. Ramakumar

1990-01-01

24

Integrated vs. Stand-Alone Systems.  

ERIC Educational Resources Information Center

|Discusses the benefits and disadvantages for library uses of stand-alone and integrated computer systems, multi-user and single-user systems, local area networks versus shared logic systems, and the Macintosh Library System which combines features of both. (EM)|

Kline, Norman

1986-01-01

25

Dynamic behavior of a stand-alone hybrid power generation system of wind turbine, microturbine, solar array and battery storage  

Microsoft Academic Search

This paper presents dynamic behavior and simulation results in a stand-alone hybrid power generation system of wind turbine, microturbine, solar array and battery storage. The hybrid system consists of a 195xa0;kW wind turbine, an 85xa0;kW solar array; a 230xa0;kW microturbine and a 2.14xa0;kAh lead acid battery pack optimized based on economic analysis using genetic algorithm (GA). At first, a developed

M. Kalantar

2010-01-01

26

An improved PV battery charger for low cost low power stand alone low power systems  

Microsoft Academic Search

Single dwelling solar lighting systems fulfill the much-needed gaps in rural applications in less developed geographies. Many of these systems are designed to meet challenging cost objectives, but fail to consider the reliability and availability aspects. In this paper, a simple modification to the battery charging circuit for these applications is proposed that will increase the battery life and availability

Supratim Basu; Lars Norum; Dhaval Dalal

2008-01-01

27

Stand-alone PV generation system with maximum power point tracking  

Microsoft Academic Search

The power available at the output of photovoltaic (PV) cells keeps changing with solar irradiation and ambient temperature because PV cells exhibit a nonlinear current-voltage characteristic. Maximum power point tracking (MPPT) techniques are used in PV systems to make full utilization of PV array output power which depends on solar irradiation and ambient temperature. Inverter control is another key aspect

Hadi Aghazadeh; Hossein Madadi Kojabadi; Ahmad Sadeghi Yazdankhah

2010-01-01

28

A study on the stand-alone operating or photovoltaic\\/wind power hybrid generation system  

Microsoft Academic Search

Photovoltaic energy and wind energy are very in constant depending on the season, time and extremely intermittent energy sources. Because of these reasons, in view of the reliability the solar and the wind generation system have many problems(energy conversion, energy storage, load control etc.) comparing with a conventional power plant. So, in order to solve these existing problems, hybrid generation

S. J. Park; B. B. Kang; J. P. Yoon; I. S. Cha; J. Y. Lim

2004-01-01

29

Developed Algorithm of Maximum Power Tracking for Stand-Alone Photovoltaic System  

Microsoft Academic Search

The rapid increase in the cost of conventional energy sources leads to the use of nonconventional energy sources. The photovoltaic (PV) is one nonconventional source that is safe, reliable, and environmentally healthy. However, the PV system is expensive and needs a large area to operate. To solve these disadvantages, it is necessary to operate at the maximum power point (MPP)

ABD EL-SHAFY A. NAFEH; FATEN H. FAHMY; OSAMA A. MAHGOUB; ESSAM M. ABOU EL-ZAHAB

1998-01-01

30

Medium power wind mill control for stand alone energy generation  

Microsoft Academic Search

This paper will propose the study of a the control of a coupled wind turbine to a stand alone electric generator based on other renewable energies and storage systems. In this study a new method has been investigated to design the maximum power point tracking (MPPT) in order to have a good efficiency with a simple approach. From the wind

O. Ba; D. Depernet; P. Ndiaye; A. Berthon

2009-01-01

31

Analysis of a stand-alone power system for remote-site applications. Final report  

SciTech Connect

The Coast Guard has over 40 automated remote lighthouses which are powered by a continuously run, diesel-electric generator. Continuous operation of a diesel generator increases maintenance requirements as well as fuel costs. Previous studies have indicated that maintenance and operational costs at remote, automated lighthouses could be substantially reduced by incorporating a hybrid-energy-management system. Such a 120-volt system was designed, developed, and built and includes the following major components: diesel-electric generator, wind turbine generator, battery storage, inverter, system controller and lighthouse load. This report discusses the system design, the chronological record of events, conclusions, and recommendations of over three months of continuous data collection and system operation. Additionally, each major system component is discussed in detail in an appropriate appendix.

Thacker, J.R.

1986-05-01

32

ESTIMATION PROCEDURE FOR APPLICATION EFFECT OF WIND-DIESEL POWER SYSTEMS FOR STAND-ALONE USERS  

Microsoft Academic Search

The paper presents a calculation procedure of application efficiency of wind-diesel complexes in the rural electric supply system. Electrical capacity of a wind-powered generator (wind turbine) depends upon the air flow rate through the wind-wheel plane and is determined on the basis of weather data supplied by the nearest meteorological station. Under sufficient wind flow the wind turbine takes over

Vasili Sudachenko; Nickolay Zuev

2008-01-01

33

Stand-alone hybrid wind-photovoltaic power generation systems optimal sizing  

NASA Astrophysics Data System (ADS)

Wind and photovoltaic energy resources have attracted energy sectors to generate power on a large scale. A drawback, common to these options, is their unpredictable nature and dependence on day time and meteorological conditions. Fortunately, the problems caused by the variable nature of these resources can be partially overcome by integrating the two resources in proper combination, using the strengths of one source to overcome the weakness of the other. The hybrid systems that combine wind and solar generating units with battery backup can attenuate their individual fluctuations and can match with the power requirements of the beneficiaries. In order to efficiently and economically utilize the hybrid energy system, one optimum match design sizing method is necessary. In this way, literature offers a variety of methods for multi-objective optimal designing of hybrid wind/photovoltaic (WG/PV) generating systems, one of the last being genetic algorithms (GA) and particle swarm optimization (PSO). In this paper, mathematical models of hybrid WG/PV components and a short description of the last proposed multi-objective optimization algorithms are given.

Cr?ciunescu, Aurelian; Popescu, Claudia; Popescu, Mihai; Florea, Leonard Marin

2013-10-01

34

Unit sizing of stand-alone hybrid wind\\/PV\\/fuel cell power generation systems  

Microsoft Academic Search

An economic evaluation of a hybrid wind\\/photovoltaic\\/fuel cell generation system for a typical home in the Pacific Northwest is performed. In this configuration the combination of a fuel cell stack, an electrolyzer, and a hydrogen storage tank is used for the energy storage system. This system is compared to a traditional hybrid energy system with battery storage. A computer program

D. B. Nelson; M. H. Nehrir; C. Wang

2005-01-01

35

Power-Quality Improvement of a Stand-Alone Induction Generator Using a STATCOM With Battery Energy Storage System  

Microsoft Academic Search

This paper presents a STATCOM with a self-oscillating bidirectional dc-dc converter for interfacing battery energy storage in a stand-alone induction generator system. The self-oscillation mode is based on relay feedback control with hysteresis. To reduce the output current ripple, an LCL filter is connected between the half bridge of this dc-dc converter and the energy storage system. The other side

J. A. Barrado; R. Grino; H. Valderrama-Blavi

2010-01-01

36

High-Performance Stand-Alone Photovoltaic Generation System  

Microsoft Academic Search

This study develops a high-performance stand-alone photovoltaic (PV) generation system. To make the PV generation system more flexible and expandable, the backstage power circuit is composed of a high step-up converter and a pulsewidth-modulation (PWM) inverter. In the dc-dc power conversion, the high step-up converter is introduced to improve the conversion efficiency in conventional boost converters to allow the parallel

Rong-Jong Wai; Wen-Hung Wang; Chung-You Lin

2008-01-01

37

Intelligent controller for a stand-alone hybrid generation system  

Microsoft Academic Search

This paper aims at the modeling and power flow analysis of a stand-alone hybrid generating system (SAHGS) comprising of wind and photovoltaic systems. The wind driven self-excited induction generator (SEIG), photovoltaic array and other network components are modeled and simulated using Matlab\\/Simulink. The variable voltage and frequency of a generator is first rectified and controlled by a DC\\/DC converter before

S. Meenakshi; K. Rajambal; C. Chellamuthu; S. Elangovan

2006-01-01

38

A Study on Electric Power Smoothing System for Lead-Acid Battery of Stand-Alone Natural Energy Power System Using EDLC  

NASA Astrophysics Data System (ADS)

To resolve energy shortage and global warming problem, renewable natural resource and its power system has been gradually generalizing. However, the power fluctuation suppressing in short period and the balance control of consumption and supply in long period are two of main problems that need to be resolved urgently in natural energy power system. In Stand-alone Natural Energy Power System (SNEPS) with power energy storage devices, power fluctuation in short period is one of the main reasons that recharge cycle times increase and lead-acid battery early failure. Hence, to prolong the service life of lead-acid battery and improve power quality through suppressing the power fluctuation, we proposed a method of electric power smoothing for lead-acid battery of SNEPS using bi-directional Buck/Boost converter and Electric Double Layer Capacitor (EDLC) in this paper. According to the test data of existing SNEPS, a power fluctuation condition is selected and as an example to analyze the validity of the proposed method. The analysis of frequency characteristics indicates the power fluctuation is suppressed a desired range in the target frequency region. The experimental results of confirmed the feasibility of the proposed system and the results well satisfy the requirement of system design.

Jia, Yan; Shibata, Ryosuke; Yamamura, Naoki; Ishida, Muneaki

39

Power control and modeling of a solar-ultra capacitor hybrid energy system for stand-alone applications  

Microsoft Academic Search

This paper proposes the integration of photovoltaic (PV) and energy storage systems for sustained power generation. In this proposed system, whenever the PV system cannot completely meet load demands, the super capacitor provides power to meet the remaining load. A power management strategy is designed for the proposed system to manage power flows between PV systems and ultracapacitor(UC). The main

Jae Hoon Cho; Won-Pyo Hong

2010-01-01

40

A battery management system for stand alone photovoltaic energy systems  

Microsoft Academic Search

This paper outlines the development of a battery management system (BMS) for stand alone photovoltaic (PV) energy systems. The BMS calculates the state of charge (SOC) of a lead acid battery to determine the capacity over time. This enables intelligent control schemes to be implemented. A fully functioning prototype was constructed that involved both hardware and software design. Several tests

Shane Duryea; Syed Islam; William Lawrance

1999-01-01

41

The Loss of Power Supply Probability as a Technique for Designing Stand-Alone Solar Electrical (Photovoltaic) Systems  

Microsoft Academic Search

It is noted that most of the analysis and design methods used in solar electrical systems (SESs) are based on the concept of power supply during a number of autonomous days (NAD). The NAD value is the number of consecutive days on which no power is supplied to the system from the solar cell array (SCA). The storage system capacity

E. Ofry; A. Braunstein

1983-01-01

42

A new stand-alone beam emittance measurement system  

NASA Astrophysics Data System (ADS)

A unique mechanical arrangement is employed which utilizes a single Allison type emittance scanner pod. This arrangement allows scans to be taken at any rotational angle, thereby eliminating any differences that can occur between gap settings when multiple pods are used. Flexibility is enhanced since the user is not restricted to orthogonal angles. A stand alone control and data acquisition system is utilized. The architecture includes an 80386TM PC and CAMAC interfaces. Two TrekTM power supplies and a computer controlled signal generator provide maximum flexibility to the sweep voltages on the pod deflector plates. This paper describes the mechanical design of the scanner pod assembly, and the electrical and software design of the control system.

Heuer, R.; Saadatmand, K.; Solensten, L.; Debiak, T.; Sredniawski, J.; Kuehne, F.

1989-05-01

43

Improve wind energy penetration in an isolated power system by a stand-alone wind pumped storage hydropower plant  

Microsoft Academic Search

As is well-known, using pumped storage system in a power system is one of ways to raise the wind energy penetration. In former studies, the introduction of pumped storage system in power production systems aims mainly at peak clipping, valley filling of a grid and so on. In the present study, a relatively novel solution is introduced to enable wind-hydro-pumped

Kun Qian; Yuxiang Jiang; Zheng Li

2011-01-01

44

Small renewable hybrid systems for stand alone applications  

Microsoft Academic Search

To provide renewable energy to stand alone applications the generation system should be composed of different types of energy sources to make better use of the natural resources in these applications. A common practice is to combine wind and solar PV energies in the so called hybrid renewable systems. Due to the long distance, and difficult access the overall system

Luiz A. de S. Ribeiro; Osvaldo R. Saavedra; J. G. de Matos; G. Bonan; A. S. Martins

2009-01-01

45

Modeling, control and simulation of a PV\\/FC\\/UC based hybrid power generation system for stand-alone applications  

Microsoft Academic Search

Different energy sources and converters need to be integrated to meet sustained load demands while accommodating various natural conditions. This paper focuses on the integration of photovoltaic (PV), fuel cell (FC) and ultra-capacitor (UC) systems for sustained power generation. In the proposed system, during adequate insolation, the PV system feeds the electrolyzer to produce hydrogen for future use and transfers

M. Uzunoglu; O. C. Onar; M. S. Alam

2009-01-01

46

Photovoltaic stand-alone modular systems. Phase 2. Final Report  

SciTech Connect

The final hardware and system qualification phase of a two part stand-alone photovoltaic (PV) system development is covered. The final design incorporated modular, power blocks capable of expanding incrementally from 320 watts to twenty kilowatts (PK). The basic power unit (PU) was nominally rated 1.28 kWp. The controls units, power collection buses and main lugs, electrical protection subsystems, power switching, and load management circuits are housed in a common control enclosure. Photo-voltaic modules are electrically connected in a horizontal daisy-chain method via Amp Solarlok plugs mating with compatible connectors installed on the back side of each photovoltaic module. A pair of channel rails accommodate the mounting of the modules into a frameless panel support structure. Foundations are of a unique planter (tub-like) configuration to allow for world-wide deployment without restriction as to types of soil. One battery string capable of supplying approximately 240 ampere hours nominal of carryover power is specified for each basic power unit. Load prioritization and shedding circuits are included to protect critical loads and selectively shed and defer lower priority or noncritical power demands. The baseline system, operating at approximately 2 1/2 PUs (3.2 kW pk.) was installed and deployed. Qualification was successfully complete in March 1983. Since that time, the demonstration system has logged approximately 3000 hours of continuous operation under load without major incident.

Naff, G.J.; Marshall, N.A.

1983-07-01

47

Stand-alone power systems for the future: Optimal design, operation and control of solar-hydrogen energy systems.  

National Technical Information Service (NTIS)

This thesis gives a systematic review of the fundamentals of energy systems, the governing physical and chemical laws related to energy, inherent characteristics of energy system, and the availability of the earth's energy. It shows clearly why solar-hydr...

O. Ulleberg

1998-01-01

48

Costing of a stand-alone photovoltaic system  

Microsoft Academic Search

We have used a life-cycle cost analysis for a stand-alone photovoltaic system with and without an auxiliary engine generator. Because of different published cost calculations, we apply average values or new estimates in the analysis based on examinations of component lifetimes, maintenance operations, fuel consumption, components costs, percentage of installation completed, and discount rates.

G. Notton; M. Muselli; P. Poggi

1998-01-01

49

A Stand-Alone Hybrid Generation System Combining Solar Photovoltaic and Wind Turbine with Simple Maximum Power Point Tracking Control  

Microsoft Academic Search

This paper proposes a hybrid energy system combing solar photovoltaic and wind turbine as a small-scale alternative source of electrical energy where conventional generation is not practical. A simple and cost effective control technique has been proposed for maximum power point tracking from the photovoltaic array and wind turbine under varying climatic conditions without measuring the irradiance of the photovoltaic

Nabil A. Ahmed; Masafumi Miyatake

2006-01-01

50

Modeling, control and simulation of a photovoltaic power system for grid-connected and stand-alone applications  

Microsoft Academic Search

This paper proposes a hybrid system consisting of a photovoltaic (PV) array and rechargeable battery integrated to the distribution grid with the aim to perform load sharing with the distribution grid. The PV array and the battery are connected to the dc-side of the voltage source inverter (VSI) through a boost converter and buck-boost converter respectively. A power management control

K. T. Tan; P. L. So; Y. C. Chu; K. H. Kwan

2010-01-01

51

A stochastic method for stand-alone photovoltaic system sizing  

SciTech Connect

Photovoltaic systems utilize solar energy to generate electrical energy to meet load demands. Optimal sizing of these systems includes the characterization of solar radiation. Solar radiation at the Earth's surface has random characteristics and has been the focus of various academic studies. The objective of this study was to stochastically analyze parameters involved in the sizing of photovoltaic generators and develop a methodology for sizing of stand-alone photovoltaic systems. Energy storage for isolated systems and solar radiation were analyzed stochastically due to their random behavior. For the development of the methodology proposed stochastic analysis were studied including the Markov chain and beta probability density function. The obtained results were compared with those for sizing of stand-alone using from the Sandia method (deterministic), in which the stochastic model presented more reliable values. Both models present advantages and disadvantages; however, the stochastic one is more complex and provides more reliable and realistic results. (author)

Cabral, Claudia Valeria Tavora; Filho, Delly Oliveira; Martins, Jose Helvecio; Toledo, Olga Moraes [Department of Agricultural Engineering, Federal University of Vicosa, Av. P. H. Rolfs, s/n. 36570-000 Vicosa, Minas Gerais (Brazil); Diniz, Antonia Sonia Alves C.; Machado Neto, Lauro de Vilhena B. [Group of Studies in Energy - GREEN Solar, Pontifical Catholic University of Minas Gerais - PUC Minas, Rua Dom Jose Gaspar no. 500, Predio 03, Sala 218 - Coracao Eucaristico 30535-610 Belo Horizonte - Minas Gerais (Brazil)

2010-09-15

52

Stand-alone PEM water electrolysis system for fail safe operation with a renewable energy source  

Microsoft Academic Search

A complete stand-alone electrolyser system has been constructed as a transportable unit for demonstration of a sustainable energy facility based on hydrogen and a renewable energy source. The stand-alone unit is designed to support a polymer electrolyte membrane (PEM) stack operating at up to ?4kW input power with a stack efficiency of about 80% based on HHV of hydrogen. It

R. E. Clarke; S. Giddey; S. P. S. Badwal

2010-01-01

53

Study of a thermoelectric system equipped with a maximum power point tracker for stand-alone electric generation.  

NASA Astrophysics Data System (ADS)

According to the International Energy Agency, 1.4 billion people are without electricity in the poorest countries and 2.5 billion people rely on biomass to meet their energy needs for cooking in developing countries. The use of cooking stoves equipped with small thermoelectric generator to provide electricity for basic needs (LED, cell phone and radio charging device) is probably a solution for houses far from the power grid. The cost of connecting every house with a landline is a lot higher than dropping thermoelectric generator in each house. Thermoelectric generators have very low efficiency but for isolated houses, they might become really competitive. Our laboratory works in collaboration with plane`te-bois (a non governmental organization) which has developed energy-efficient multifunction (cooking and hot water) stoves based on traditional stoves designs. A prototype of a thermoelectric generator (Bismuth Telluride) has been designed to convert a small part of the energy heating the sanitary water into electricity. This generator can produce up to 10 watts on an adapted load. Storing this energy in a battery is necessary as the cooking stove only works a few hours each day. As the working point of the stove varies a lot during the use it is also necessary to regulate the electrical power. An electric DC DC converter has been developed with a maximum power point tracker (MPPT) in order to have a good efficiency of the electronic part of the thermoelectric generator. The theoretical efficiency of the MMPT converter is discussed. First results obtained with a hot gas generator simulating the exhaust of the combustion chamber of a cooking stove are presented in the paper.

Favarel, C.; Champier, D.; Bédécarrats, J. P.; Kousksou, T.; Strub, F.

2012-06-01

54

A genetic algorithm based battery model for Stand Alone Radio Base Stations powering  

Microsoft Academic Search

This paper focuses on energy storage devices to be used in Stand Alone and Radio Base Stations powering, where performance analysis of different storage systems must be made taking into account the typical operating conditions. A Lithium Polymer (LiPo) cell model whose parameters have been identified through a combination of least mean square and genetic algorithms has been used to

G. Fabbri; M. Paschero; A. J. M. Cardoso; C. Boccaletti; F. M. Frattale Mascioli

2011-01-01

55

US manufacturers of commercially available stand-alone photovoltaic lighting systems  

SciTech Connect

This report introduces photovoltaic (PV) lighting systems, gives some specifications for ordering these systems, and provides a list of some of the manufacturers of these systems in the United States. These PV lighting systems are all commercially available. They are stand-alone systems because they are not tied to the electric utility power grid.

McNutt, P.

1994-05-01

56

A battery management system for stand-alone photovoltaic energy systems  

Microsoft Academic Search

It is estimated that about 80% of all photovoltaic (PV) modules are used in stand-alone applications. Continuous power is obtained from PV systems by using a storage buffer, typically in the form of a lead acid battery. Batteries used in PV applications have different performance characteristics compared with batteries used in more traditional applications. In PV applications, lead acid batteries

S. Duryea; S. Islam; W. Lawrance

2001-01-01

57

Integrated control of a stand-alone photovoltaic system based on decentralized DC-DC converters  

Microsoft Academic Search

This paper presents a scheme for supervisory control of decentralized stand-alone PV systems. The control is designed to maintain the DC bus regulated independently of solar irradiation, battery charge and load demands. In order to achieve this objective we propose an overall power management strategy to control power flows among PV arrays, battery bank, and inverter. Experimental results for a

Diogo B. Cândido; Leandro Michels; Hélio L. Hey

2010-01-01

58

Stand-alone and Network Capable Pocket Radiation Detection System  

SciTech Connect

A multi-functional and networked pocket radiation detection system has been developed at the Idaho National Laboratory (INL) capable of detecting and storing gamma ray and neutron data. The device can be used as a stand-alone device or in conjunction with an array to cover a small or large area. The device has programmable alarm trigger levels that can be modified for specific applications. The data is stored with a date/time stamp and can be transferred and viewed on a PDA via direct connection or, in networked configuration, wireless connection to a remote central facility upon request. Data functional/bench tests have been completed successfully and the device was demonstrated to detect radiation from a 55.6 uCi Cf-252 source at 5 meters and from 1.4 mCi Cf-252 source at 10 meters which exceeds both ANSI and IAEA standards for pocket radiation detection. In terms of sensitivity, this detection system detects neutron and gamma-ray fields down to 10 micro rem/hr levels and therefore can find the location of the radioactive source quickly. The detection system is small enough to be put in a pocket or clipped to a belt.

R. Aryaeinejad

2009-03-01

59

Compressed-air energy storage systems for stand-alone off-grid photovoltaic modules  

Microsoft Academic Search

In this work, a low-cost, low-volume, low-maintenance, small-scale compressed-air energy storage system (SS-CAES) is proposed, which can be used in conjunction with off-grid stand-alone photo-voltaic panels, for powering appliances and residential units in order to minimize the dependency on centralized power system grids. As a first step towards achieving this objective, we have designed and examined the compression efficiency of

Dominique Villela; Vijayanathan Veerasamy Kasinathan; Scott De Valle; Mark Alvarez; George Frantziskonis; Pierre Deymier; Krishna Muralidharan

2010-01-01

60

A voltage controller in photo-voltaic system without battery storage for Stand-Alone Applications  

Microsoft Academic Search

The paper proposes the new voltage controller in photo-voltaic system for Stand-Alone Applications without battery energy storage. The output of the PV array is unregulated DC supply due to change in weather conditions. The maximum power is tracked with respect to temperature and irradiance levels by using DC-DC converter. The perturbation and observes algorithm is applied for maximum power point

S. Senthil Kumar; Ganesh Dharmireddy; P. Raja; S. Moorthi

2011-01-01

61

Optimal coordination control for stand-alone PV system with nonlinear load  

Microsoft Academic Search

This paper presents a stand-alone photovoltaic system with Ni-Mh battery serving as its energy storage element. The proposed system is composed of a boost converter, a bidirectional DC\\/DC converter and a single-phase DC\\/AC inverter. The boost converter is used to track the maximum power point of the solar panel whereas the bidirectional DC\\/DC converter is applied to maintain the DC-link

Xiong Liu; Peng Wang; Poh Chiang Loh

2010-01-01

62

Generation unit sizing and cost analysis for stand-alone wind, photovoltaic, and hybrid wind\\/PV systems  

Microsoft Academic Search

This paper presents the results of investigations on the application of wind, photovoltaic (PV), and hybrid wind\\/PV power generating systems for utilization as stand-alone systems. A simple numerical algorithm has been developed for generation unit sizing. It has been used to determine the optimum generation capacity and storage needed for a stand-alone, wind, PV, and hybrid wind\\/PV system for an

W. D. Kellogg; M. H. Nehrir; G. Venkataramanan; V. Gerez

1998-01-01

63

System design optimization for stand-alone photovoltaic systems sizing by using superstructure model  

NASA Astrophysics Data System (ADS)

Although the photovoltaic (PV) systems have been increasingly installed as an alternative and renewable green power generation, the initial set up cost, maintenance cost and equipment mismatch are some of the key issues that slows down the installation in small household. This paper presents the design optimization of stand-alone photovoltaic systems using superstructure model where all possible types of technology of the equipment are captured and life cycle cost analysis is formulated as a mixed integer programming (MIP). A model for investment planning of power generation and long-term decision model are developed in order to help the system engineer to build a cost effective system.

Azau, M. A. M.; Jaafar, S.; Samsudin, K.

2013-06-01

64

An Improved Utility Interface for Microturbine Generation System With Stand-Alone Operation Capabilities  

Microsoft Academic Search

In this paper, an alternative filter and control approach for the design of a microturbine's utility interface is proposed. The new method employs a unified current-regulated controller to drive the system converter as a power conditioner for the grid-tied operation and an emergent generator for the stand-alone operation, where few current sensors are required to serve the controller for both

Fu-Sheng Pai

2006-01-01

65

Stand-alone photovoltaic (PV) powered electrochromic window  

DOEpatents

A variable transmittance double pane window includes an electrochromic material that has been deposited on one pane of the window in conjunction with an array of photovoltaic cells deposited along an edge of the pane to produce the required electric power necessary to vary the effective transmittance of the window. A battery is placed in a parallel fashion to the array of photovoltaic cells to allow the user the ability to manually override the system when a desired transmittance is desired. 11 figures.

Benson, D.K.; Crandall, R.S.; Deb, S.K.; Stone, J.L.

1995-01-24

66

Sizing photovoltaic systems components for stand-alone operation  

Microsoft Academic Search

The practicality of using solar photovoltaic panels combined with batteries and controls to generate emergency power in Maine is presented. Solar power is becoming less costly and more available, making the design and fabrication of emergency power and lighting highly feasible. This paper discusses the sizing, design, construction, and testing of such a system. The distinctions between the total power

J. Masi; C. Nadeau; J. Smith

2007-01-01

67

A simple and efficacious control system for stand alone generation plants equipped with induction machines  

Microsoft Academic Search

The paper presents a novel control algorithm, for a stand alone generation plant equipped with induction machine. The aim of control is to regulate properly the voltage and frequency generation of induction machine during load power changes. A \\

Andrea Del Pizzo; Diego Iannuzzi; Luigi Piegari; Stefano Baratto; Umberto Macri

2006-01-01

68

An approach to evaluate the general performance of stand-alone wind\\/photovoltaic generating systems  

Microsoft Academic Search

This paper reports the development of a computer approach for evaluating the general performance of stand-alone wind\\/photovoltaic generating systems. Simple models for different system components are developed, integrated, and used to predict the behavior of generating systems based on available wind\\/solar and load data. The model is useful for evaluating the performance of stand-alone generating systems and gaining a better

M. Hashem Nehrir; Brock J. LaMeres; Giri Venkataramanan; Victor Gerez; L. A. Alvarado

2000-01-01

69

Control of hybrid battery\\/ultra-capacitor energy storage for stand-alone photovoltaic system  

Microsoft Academic Search

Battery life is an important criterion in a stand-alone photovoltaic system operation due to intermittent characteristic of solar irradiation and demand. This paper presents a stand-alone photovoltaic system with Ni-MH battery and ultra-capacitor serving as its energy storage elements. A control strategy is proposed in this paper to reduce charging and discharging cycles and avoid deep discharges of battery. The

Xiong Liu; Peng Wang; Poh Chiang Loh; Feng Gao; Fook Hoong Choo

2010-01-01

70

Characterization of Stand Alone AC Generators During No-Break Power Transfer Using Radial Basis Networks  

Microsoft Academic Search

This paper describes the use of an artificial intelligence-electromagnetic modeling approach for the performance prediction of stand alone synchronous generators during no break power transfer (NBPT) operating conditions. This approach uses radial basis networks (RBNs), which have the advantage of not being locked into local minima as could do feedforward neural networks. The RBNs are simply linear function approximators that

A. A. Arkadan; Y. Abou-Samra; N. Al-Aawar

2007-01-01

71

Brackish water desalination by a stand alone reverse osmosis desalination unit powered by photovoltaic solar energy  

Microsoft Academic Search

Desalination of brackish water as a viable option to cope with water scarcity and to overcome water deficit in Jordan is assessed. A stand alone reverse osmosis (RO) desalination unit powered by photovoltaic (PV) solar energy is proposed, and a computer code in C++ was generated in order to simulate the process, and to predict the water production at 10

Eyad S. Hrayshat

2008-01-01

72

A novel active filter strategy for power mitigation and quality enhancements in a stand-alone WECS  

Microsoft Academic Search

In this study, a novel sinusoidal PWM Switched Power Filter (SPF) and Dynamic Voltage Compensation (DVC) scheme using VSC\\/SMC\\/B-B controller for power mitigation and quality enhancements in medium power distribution systems are simulated. The system is based upon a stand-alone Wind Energy Conversion Scheme (WECS) using an induction generator and the proposed system control mechanisms, which are digitally simulated by

Ismail H. Altas; Emre Ozkop; Adel M. Sharaf

2009-01-01

73

Integration of a stand-alone expert system with a hospital information system.  

PubMed

A stand-alone PC expert system for evaluating the appropriateness of inpatient admissions has been integrated with an existing hospital information system. The expert system supports preadmission screening for appropriateness of inpatient admissions. The HIS provides extensive clinical data in a coded electronic form, permitting high-level decision support. The integrated system was developed for a 20 week randomized clinical trial to evaluate the effects of preadmission screening on inappropriate inpatient admissions. Three factors of the integration are considered: programmatic integration of the expert system, seamless presentation of mixed platform applications, and integration of coded data from the stand-alone application into the HIS data structure. PMID:1482911

Hales, J W; Gardner, R M; Huff, S M

1992-01-01

74

4-E (energy–exergy–environmental–economic) analyses of line-focusing stand-alone concentrating solar power plants  

Microsoft Academic Search

In this study, energy–exergy–environmental–economic (4-E) analyses of stand-alone line-focusing concentrating solar power plants are carried out for different plant capacities ranging from 1 to 50 MWe<\\/sub>. Solar power plants based on concentrating power technologies are used to harness the solar radiation effectively. Among the solar power technologies, line-focusing concentrating systems such as linear Fresnel reflector (LFR) and parabolic trough collector

K. Ravi Kumar; K. S. Reddy

2012-01-01

75

Combined Photovoltaic \\/ Thermal Energy System for Stand-alone Operation  

Microsoft Academic Search

The utilization of solar energy can be made by photovoltaic (PV) cells to generate electric power directly and solar thermal (T) panels can be applied to generate heat power. When the utilization of the solar energy is necessary to generate electric power, the option of using T panels in combination with some heat \\/ electric power conversion technology can be

Rafael K. Jardan; Istvan Nagy; Angel Cid-Pastor; Ramon Leyva; Abdelali El Aroudi; Luis Martinez-Salamero

2007-01-01

76

An operating systems course using stand alone computers  

Microsoft Academic Search

Curriculum '78 [3] describes a course in Operating Systems and Computer Architecture. In the course outline it is stated, “The laboratory for this course would ideally use a small computer where the students could actually implement sections of operating systems and have them fail without serious consequence to other users”. Also in the recommendations for the Software Engineering Subject Area

Samuel J. Wiley

1982-01-01

77

Efficiency of hydrogen based storage systems for stand-alone PV applications: Numerical and experimental results  

Microsoft Academic Search

Photovoltaic (PV) technology is playing an important role as clean and long lasting electrical source. Energy storage is a prerequisite for using PV energy in stand-alone applications, in smart grid and for increase system reliability. Observing that today the hydrogen is an emerging solution as energy vector, PV-hydrogen system can be studied. The paper discusses the integration between the PV

D. Iannuzzi; M. Pagano

2009-01-01

78

Secure Stand Alone Positive Personnel Identity Verification System (SSA-PPIV).  

National Technical Information Service (NTIS)

The properties of a secure stand-alone positive personnel identity verification system are detailed. The system is designed to operate without the aid of a central computing facility and the verification function is performed in the absence of security pe...

P. D. Merillat

1979-01-01

79

Performance of a 268 Wp stand-alone PV system test facility  

Microsoft Academic Search

This paper reports on studies carried out on a 268 Wp stand-alone PV test facility installed at the University of Ghana. Parameters measured include solar irradiance, ambient temperature, cell temperature, array voltage, battery voltage, and energy output from the array. An automatic data acquisition system was used to record the data. The purpose of this study was to determine the

K. G. Adanu

1994-01-01

80

Stand Alone Wind Energy Conversion System Based on Functional Predictive Control  

Microsoft Academic Search

This paper investigates the application of the model predictive control (MPC) approach to control the voltage and frequency of a stand alone wind generation system. This scheme consists of a wind turbine which drives an induction generator feeding an isolated load. A static Var compensator (SVC) is connected at the induction generator terminals to regulate the load voltage. The rotor

Ali M. Yousef; Ahmed M. Kassem

2012-01-01

81

An improved control method for DFIG-based wind system supplying unbalanced stand-alone loads  

Microsoft Academic Search

This paper proposes a novel control method for operation of a DFIG-based wind generator under unbalanced stand-alone loads, connected directly with stator terminal of the generator. The effect of unbalance condition at loads causes torque pulsations on generator and the stator voltage unbalance that degrade the dynamic behavior of control system. To eliminate the negative sequence components existing in generated

Van-Tung Phan; Sung-Hyo Kwak; Hong-Hee Lee

2009-01-01

82

Automated stand-alone flow injection immunoanalysis system for the determination of cephalexin in milk  

Microsoft Academic Search

A fully automated stand-alone flow injection immunoanalysis (FIIA) device for the determination of cephalexin in milk is developed with a main focus on the investigation of the influence of the sample matrix. The system is based on principles of flow-through immunoassays and on sequential addition of the assay components to an immunoreactor. Protein G is immobilised on the surface of

Ulrich J. Meyer; Zheng-Liang Zhi; Markus Meusel; Friedrich Spener; Elma Loomans

1999-01-01

83

Information systems for the materials management department: stand-alone and enterprise resource planning systems.  

PubMed

Materials management information systems (MMISs) incorporate information tools that hospitals can use to automate certain business processes, increase staff compliance with these processes, and identify opportunities for cost savings. Recently, there has been a push by hospital administration to purchase enterprise resource planning (ERP) systems, information systems that promise to integrate many more facets of healthcare business. We offer this article to help materials managers, administrators, and others involved with information system selection understand the changes that have taken place in materials management information systems, decide whether they need a new system and, if so, whether a stand-alone MMIS or an ERP system will be the best choice. PMID:15887634

2005-03-01

84

Methodology for optimal sizing of stand-alone photovoltaic\\/wind-generator systems using genetic algorithms  

Microsoft Academic Search

A methodology for optimal sizing of stand-alone PV\\/WG systems is presented. The purpose of the proposed methodology is to suggest, among a list of commercially available system devices, the optimal number and type of units ensuring that the 20-year round total system cost is minimized subject to the constraint that the load energy requirements are completely covered, resulting in zero

Eftichios Koutroulis; Dionissia Kolokotsa; Antonis Potirakis; Kostas Kalaitzakis

2006-01-01

85

A new control method for VRB SOC estimation in stand-alone wind energy systems  

Microsoft Academic Search

This paper proposes the integration of a vanadium redox flow battery (VRB) system with a typical stand-alone wind energy system during wind speed variation as well as transient performance under variable load. The investigated system consists of a 3 kW variable speed wind turbine with permanent magnet synchronous generator (PMSG), diode rectifier bridge, buck-boost converter, bidirectional charge controller, transformer, inverter,

L. Barote; C. Marinescu

2009-01-01

86

A Novel Voltage Stabilization Control Scheme for Stand-alone Wind Energy Conversion Systems  

Microsoft Academic Search

This paper proposes a novel low cost FACTS based voltage stabilization scheme for a stand-alone wind energy conversion systems using self excited squirrel-cage induction generator (SEIG) driven by a wind turbine and interfaced to electric load. The new control scheme is designed not only to ensure bus voltage stabilization, but also to improve energy utilization using a low-cost PWM-switched modulated

A. M. Sharaf; A. Aljankawey; I. H. Altas

2007-01-01

87

Stand-alone WIreless Magnetometer System: Concept Design and Development Status  

NASA Astrophysics Data System (ADS)

The Stand-alone WIreless Magnetometer System (SWIMS) is intended to serve as a technology suitable for large scale deployment for magnetometer networks in sub-auroral latitudes with minimal logistical support and maintenance. SWIMS is based on a new magnetometer developed and licensed by JHU/APL. A SWIMS installation will consist of up to three solar/battery powered Sensor Modules (SM) each equipped with a new Mirror Image Differential Induction Amplitude Magnetometer (MIDIAM). The SMs are linked via wireless, radio frequency (RF) connection to a Central Node (CN). The RF link allows wireless installation over distances up to 300 meters between SMs. The CN may communicate either via land lines or wireless links to a central data facility. Because each SM is wireless, SWIMS can use more than one SM at a single site to discriminate against local noise sources. The present project objective is to develop a prototype SWIMS system of three SMs communicating via local RF link to a CN. The MIDIAM has yielded sub-nT performance with less than 1W power consumption in continuous operation. A conceptual system design using commercial solar/batter power system and RF communication components has been developed that is expected to achieve continuous operation at 1- second or higher rate sampling using a moderately sized solar cell array, 12" x 18", and a 6"x6"x4" AGM battery (144 W-hour). By monitoring the battery depth of discharge and duty cycling MIDIAM as required if incident effective power is low due to inclement conditions, the SM is expected to support continuous unattended operation with no coarser than one sample per minute on as little as four hours of sunlight every ten days.

Anderson, B. J.; Carkhuff, B. G.; Rhodes, E.; Korth, H.

2007-12-01

88

MATLAB\\/SIMULINK based teaching system for a Stand-Alone Energy System Supported by totally renewable hydrogen production  

Microsoft Academic Search

This paper describes the MATLAB\\/SIMULINK modeling for a Stand-Alone Energy System Supported by Totally Renewable Hydrogen Production. The full modelling of a stand-alone Energy System is a huge task implying heavy computation models with long computation times. Therefore, the full modelling approach cannot be used for teaching purposes. In this way, this paper describes a simplified model that is being

João P. Simões; Miguel C. Coelho; V. Fernão Pires; J. F. Martins

2009-01-01

89

Grid-enabled ANT compatible with both stand-alone and grid-based computing systems  

US Patent & Trademark Office Database

A grid-enabled ANT system that includes ANT XML task files that can run on both grid-enabled machines or stand-alone computers is disclosed. A network file server is used to store files accessed during the build process, and ANT's standard XML tagging and parameters are used, thus enabling the user to use a standardized format for entering XML information. This grid-enabled ANT is transparent to the user since ANT parses the tasks and automatically sends jobs to the grid, when appropriate, instead of the user deciding which tasks to implement as grid tasks.

2007-12-25

90

Characterization of Stand Alone AC Generators during No-Break Power Transfer using AI-EM Based Approach  

Microsoft Academic Search

This paper describes the use of artificial intelligence, - electromagnetic, AI-EM modeling approach for the performance prediction of stand alone synchronous generators during power transfer. This approach uses radial basis function, RBF, based data mining algorithm to evaluate the stresses accompanying the no break power transfer, NBPT. This mode of operation may result in the failure of the diodes in

A. A. Arkadan; N. Al Aawar; Y. Abou-Samra

2006-01-01

91

Battery and charge controller evaluations in small stand-alone PV systems  

SciTech Connect

We report the results of to separate long-term tests of batteries and charge controllers in small stand-alone PV systems. In these experiments, seven complete systems were tested for two years at each of two locations: Sandia National Laboratories in Albuquerque and the Florida Solar Energy Center in Cape Canaveral, Florida. Each system contained a PV array, flooded-lead-acid battery, a charge controller and a resistive load. Performance of the systems was strongly influenced by the difference in solar irradiance at the two sites, with some batteries at Sandia exceeding manufacturer`s predictions for cycle life. System performance was strongly correlated with regulation reconnect voltage (R{sup 2} correlation coefficient = 0.95) but only weakly correlated with regulation voltage. We will also discuss details of system performance, battery lifetime and battery water consumption.

Woodworth, J.R.; Thomas, M.G.; Stevens, J.W. [Sandia National Labs., Albuquerque, NM (United States); Dunlop, J.L.; Swamy, M.R.; Demetrius, L. [Florida Solar Energy Center, Cape Canaveral, FL (United States); Harrington, S.R. [K-Tech Corp., Albuquerque, NM (United States)

1994-07-01

92

Fundamental-Frequency-Modulated Six-Level Diode-Clamped Multilevel Inverter for Three-Phase Stand-Alone Photovoltaic System  

SciTech Connect

This paper presents a fundamental-frequency-modulated diode-clamped multilevel inverter (DCMLI) scheme for a three-phase stand-alone photovoltaic (PV) system. The system consists of five series-connected PV modules, a six-level DCMLI generating fundamental-modulation staircase three-phase output voltages, and a three-phase induction motor as the load. In order to validate the proposed concept, simulation studies and experimental measurements using a small-scale laboratory prototype are also presented. The results show the feasibility of the fundamental frequency switching application in three-phase stand-alone PV power systems.

Ozdemir, Engin [ORNL; Ozdemir, Sule [Oak Ridge National Laboratory (ORNL); Tolbert, Leon M [ORNL

2009-01-01

93

Stand-alone low energy measurements of light nuclei from PAMELA Time-of-Flight system  

NASA Astrophysics Data System (ADS)

The PAMELA experiment, built to detect charged particles in Cosmic Rays, is in orbit since June 2006. The Time-of-Flight system, composed by 24 scintillation counters arranged in three double view planes, is a key element of the apparatus: it generates the general trigger, provides measurements of the velocity of the particles entering the detector and allows rejection of albedo particles. It also operates identification of light nuclei up to Oxygen by means of measurements of the ionizing energy loss of the particles inside the scintillation counters. The procedure applied to obtain the atomic number and the kinetic energy per nucleon of a traversing nucleus starting from measurements of, respectively, energy loss and velocity of the nucleus itself will be described in this work. As an application, a completely stand-alone measurement from ToF of the B/C ratio below few GeV will be shown.

Carbone, Rita; PAMELA Collaboration

2012-11-01

94

A Low-Power Stand-Alone Adaptive Circuit for Harvesting Energy From a Piezoelectric Micropower Generator  

Microsoft Academic Search

An adaptive energy-harvesting circuit with low power dissipation is presented and demonstrated, which is useful for efficient ac\\/dc voltage conversion of a piezoelectric micropower generator. The circuit operates stand-alone, and it extracts the piezoelectric strain energy independent of the load and piezoelectric parameters without using any external sensor. The circuit consists of a voltage-doubler rectifier, a step-down switching converter, and

Ahmadreza Tabesh; Luc G. Frechette

2010-01-01

95

ACE16k based stand-alone system for real-time pre-processing tasks  

NASA Astrophysics Data System (ADS)

This paper describes the design of a programmable stand-alone system for real time vision pre-processing tasks. The system's architecture has been implemented and tested using an ACE16k chip and a Xilinx xc4028xl FPGA. The ACE16k chip consists basically of an array of 128x128 identical mixed-signal processing units, locally interacting, which operate in accordance with single instruction multiple data (SIMD) computing architectures and has been designed for high speed image pre-processing tasks requiring moderate accuracy levels (7 bits). The input images are acquired using the optical input capabilities of the ACE16k chip, and after being processed according to a programmed algorithm, the images are represented at real time on a TFT screen. The system is designed to store and run different algorithms and to allow changes and improvements. Its main board includes a digital core, implemented on a Xilinx 4028 Series FPGA, which comprises a custom programmable Control Unit, a digital monochrome PAL video generator and an image memory selector. Video SRAM chips are included to store and access images processed by the ACE16k. Two daughter boards hold the program SRAM and a video DAC-mixer card is used to generate composite analog video signal.

Carranza, Luis; Jimenez-Garrido, Francisco; Linan-Cembrano, Gustavo; Roca, Elisenda; Espejo Meana, Servando; Rodriguez-Vazquez, Angel

2005-06-01

96

Design and analysis of a switched reluctance generator for rural electrification in stand alone wind energy coversion system  

Microsoft Academic Search

This paper addresses the need for the exploration of utilization of maintenance free electric machines in non-conventional energy conversion systems. In stand alone wind energy conversion system meant for rural areas, cost effective and maintenance free electric machine as generator is envisaged to be an integral part of the system. The suitability of switched reluctance machine as generator for stand

R. Karthikeyan; K. Vijayakumar; R. Arumugam; V. Kamaraj

2009-01-01

97

A sequential simulation method for the generating capacity adequacy evaluation of small stand-alone wind energy conversion systems  

Microsoft Academic Search

This paper describes a sequential Monte Carlo simulation method for generating capacity adequacy evaluation of small stand-alone wind energy conversion systems containing battery storage. The wind speed, the energy conversion by the wind turbine generator, the equipment reliability and the energy storage facilities are major factors influencing the reliability performance of a wind energy conversion system. Time series models were

Roy Billinton; Bagen

2002-01-01

98

Direct Voltage Control for a Stand-Alone Wind-Driven Self-Excited Induction Generator With Improved Power Quality  

Microsoft Academic Search

An improved direct voltage control (DVC) strategy is proposed for the control of terminal voltage and frequency of a stand-alone wind-driven self-excited induction generator with vari- able loads. The DVC strategy, including a proportional-integral (PI) regulator, lead-lag corrector, and a feed-forward compen- sator, is designed based on the system transfer function matrix. The PI regulator can eliminate the steady-state tracking

Hua Geng; Bin Wu; Wei Huang

2011-01-01

99

Research issues on stand-alone pv\\/hybrid systems: state-of-art and future technology perspectives for the integration of ?grid topologies on local island grids  

Microsoft Academic Search

A review of the state-of-art on stand-alone PV\\/hybrid is presented in this paper. Gathered data on operational experiences of autonomous power stations on Hellenic islands show that energy production costs using conventional power supply sources is high and PV systems is a sustainable solution for electrification of distant areas. Emphasis is put on muGrid systems as these topologies have certain

Christos Protogeropoulos; Stathis Tselepis; Aristomenis Neris

2006-01-01

100

Cogging torque reduction in Dual-Rotor Permanent Magnet Generator for Direct Coupled Stand-Alone Wind Energy Systems  

Microsoft Academic Search

In a permanent magnet machine cogging torque is produced due to the interaction between the rotor magnets and the slots and teeth of the stator. This paper is a result of an ongoing research work that deals with reduction of cogging torque in dual-rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand-alone wind energy systems. The DRFPMG is

P. Sivachandran; P. Venkatesh; N. Kamaraj

2008-01-01

101

Low-loss DC to AC converter system for stand alone photovoltaic applications  

Microsoft Academic Search

A composite converter with a high-frequency link was investigated for stand alone DC-to-AC-conversion applications such as batteries charged by photovoltaic panels. The secondary converter was a supply-commutated high-frequency bridge, while the primary inverter was investigated further. A center-tap transformer inverter was chosen, and two approaches were used to minimize switching losses. The first approach was to implement regenerative snubbers. The

C. J. Simpson; J. D. van Wyk; J. J. Schoeman

1992-01-01

102

Sizing of a stand-alone hybrid wind-photovoltaic system using a three-event probability density approximation  

Microsoft Academic Search

The PV-array and battery storage sizing of a stand-alone hybrid wind-photovoltaic system is being addressed here. A probabilistic approach is used to arrive at the results. A new technique using a three event probability density instead of the traditional two event approximation is developed. This technique is then used to determine the optimum relationship between the number of PV panels

A. D. Bagul; Z. M. Salameh; B. Borowy

1996-01-01

103

Optimization of the photovoltaic-hydrogen supply system of a stand-alone remote-telecom application  

Microsoft Academic Search

Hydrogen is considered as the optimal carrier for the surplus energy storage from renewable resources. Although hydrogen and its application in fuel cell is considered as a high-cost energy system, some cost-efficient solutions have been found for their use in stand-alone applications, which usually depend on the variability of renewable sources that have to be oversized in order to reduce

Guillermo Gómez; Graciano Martínez; José L. Gálvez; Raúl Gila; Raquel Cuevas; Jesús Maellas; Emilio Bueno

2009-01-01

104

Expert systems design of stand-alone PV systems for export  

Microsoft Academic Search

Current system export practice is reviewed, and a promising export region, Nigeria, is selected and surveyed for resources and markets. An expert system design method is developed. The design optimization method appears promising for feasibility studies and optimal design of individual PV power systems. The life-cycle costs of the optimized PV drinking water pumping system appear to be within economic

J. Duffy; H. Campbell; E. Sanz; E. Kern

1988-01-01

105

A dynamic model for a stand-alone PEM fuel cell power plant for residential applications  

Microsoft Academic Search

A dynamic electrochemical simulation model of a grid independent proton exchange membrane (PEM) fuel cell power plant is presented. The model includes the methanol reformer, the PEM stack, and the power conditioning unit. The model is then used to predict the output voltage and study the transient response of a PEM power plant when subjected to rapid changes in a

M. Y. El-Sharkh; A. Rahman; M. S. Alam; P. C. Byrne; A. A. Sakla; T. Thomas

2004-01-01

106

Fuzzy logic control of stand-alone photovoltaic system with battery storage  

Microsoft Academic Search

Photovoltaic energy has nowadays an increased importance in electrical power applications, since it is considered as an essentially inexhaustible and broadly available energy resource. However, the output power provided via the photovoltaic conversion process depends on solar irradiation and temperature. Therefore, to maximize the efficiency of the photovoltaic energy system, it is necessary to track the maximum power point of

S. Lalouni; D. Rekioua; T. Rekioua; E. Matagne

2009-01-01

107

PV Prius; 8: Terrestrial PV Systems 8.1 Stand Alone Systems, Including Hybrid Systems  

Microsoft Academic Search

The major automobile manufacturers are producing hybrid automobiles, which are part electric and part gasoline powered. Could these automobiles take another step and obtain some of their fuel from the sun? Solar Electrical Vehicles has developed a prototype PV Prius to help answer that question. The PV Prius is fitted with a custom molded fiberglass photovoltaic module. Solar Electrical Vehicles

E. J. Simburger; J. T. Simburger; M. Bagnall

2006-01-01

108

A simplified propeller turbine runner design for stand alone micro-hydro power generation units  

Microsoft Academic Search

In most developing countries, the vast majority of potential micro-hydro power generation sites, i.e. with power outputs up to 100kW, are found in areas with high rainfall or extensive irrigation works with small canal drops. These sites, where the available head does not exceed 5m, are usually referred to as low head sites. The present paper introduces a simplified design

G. M. Demetriades; A. A. Williams; N. P. A. Smith

1996-01-01

109

Stand-Alone Front-End System for High-Frequency, High-Frame-Rate Coded Excitation Ultrasonic Imaging  

PubMed Central

A stand-alone front-end system for high-frequency coded excitation imaging was implemented to achieve a wider dynamic range. The system included an arbitrary waveform amplifier, an arbitrary waveform generator, an analog receiver, a motor position interpreter, a motor controller and power supplies. The digitized arbitrary waveforms at a sampling rate of 150 MHz could be programmed and converted to an analog signal. The pulse was subsequently amplified to excite an ultrasound transducer, and the maximum output voltage level achieved was 120 Vpp. The bandwidth of the arbitrary waveform amplifier was from 1 to 70 MHz. The noise figure of the preamplifier was less than 7.7 dB and the bandwidth was 95 MHz. Phantoms and biological tissues were imaged at a frame rate as high as 68 frames per second (fps) to evaluate the performance of the system. During the measurement, 40-MHz lithium niobate (LiNbO3) single-element lightweight (<0.28 g) transducers were utilized. The wire target measurement showed that the ?6-dB axial resolution of a chirp-coded excitation was 50 µm and lateral resolution was 120 µm. The echo signal-to-noise ratios were found to be 54 and 65 dB for the short burst and coded excitation, respectively. The contrast resolution in a sphere phantom study was estimated to be 24 dB for the chirp-coded excitation and 15 dB for the short burst modes. In an in vivo study, zebrafish and mouse hearts were imaged. Boundaries of the zebrafish heart in the image could be differentiated because of the low-noise operation of the implemented system. In mouse heart images, valves and chambers could be readily visualized with the coded excitation.

Park, Jinhyoung; Hu, Changhong; Shung, K. Kirk

2012-01-01

110

Stand-alone front-end system for high- frequency, high-frame-rate coded excitation ultrasonic imaging.  

PubMed

A stand-alone front-end system for high-frequency coded excitation imaging was implemented to achieve a wider dynamic range. The system included an arbitrary waveform amplifier, an arbitrary waveform generator, an analog receiver, a motor position interpreter, a motor controller and power supplies. The digitized arbitrary waveforms at a sampling rate of 150 MHz could be programmed and converted to an analog signal. The pulse was subsequently amplified to excite an ultrasound transducer, and the maximum output voltage level achieved was 120 V(pp). The bandwidth of the arbitrary waveform amplifier was from 1 to 70 MHz. The noise figure of the preamplifier was less than 7.7 dB and the bandwidth was 95 MHz. Phantoms and biological tissues were imaged at a frame rate as high as 68 frames per second (fps) to evaluate the performance of the system. During the measurement, 40-MHz lithium niobate (LiNbO(3)) single-element lightweight (<;0.28 g) transducers were utilized. The wire target measure- ment showed that the -6-dB axial resolution of a chirp-coded excitation was 50 ?m and lateral resolution was 120 ?m. The echo signal-to-noise ratios were found to be 54 and 65 dB for the short burst and coded excitation, respectively. The contrast resolution in a sphere phantom study was estimated to be 24 dB for the chirp-coded excitation and 15 dB for the short burst modes. In an in vivo study, zebrafish and mouse hearts were imaged. Boundaries of the zebrafish heart in the image could be differentiated because of the low-noise operation of the implemented system. In mouse heart images, valves and chambers could be readily visualized with the coded excitation. PMID:23443698

Park, Jinhyoung; Hu, Changhong; Shung, K Kirk

2011-12-01

111

Implementation of a stand-alone photovoltaic system based on decentralized dc-dc converters  

Microsoft Academic Search

This paper presents an alternative for standalone PV systems that performs a decentralized input energy processing with maximum power point tracking and a bidirectional converter to manage the power flux control of the battery bank. Previous works demonstrate that the gain in efficiency can reach up to 16% in situations where one or more photovoltaic panels are shaded, damaged or

Diogo Brum Cândido; Jonatan Rafael Rakoski Zientarski; Rafael Concatto Beltrame; José Renes Pinheiro; Hélio Leães Hey

2009-01-01

112

Integrating Fuel Cell\\/Electrolyzer\\/Ultracapacitor System Into a Stand-Alone Microhydro Plant  

Microsoft Academic Search

This paper explores the control and operational aspects of introducing fuel cell\\/electrolyzer\\/ultracapacitor (FC\\/ELZ\\/UC) unit into a microhydro power system, replacing the conventional electronic load controller\\/dump-load unit. FC\\/ELZ is expected to provide long-term energy balance by utilizing the hydrogen technology, whereas the UC is employed as buffer storage for the transient compensation. System configuration is proposed, control scheme is designed, and

Netra Gyawali; Yasuharu Ohsawa

2010-01-01

113

Development of a Laser-Powered Dielectric Structure-Based Accelerator as a Stand-Alone Particle Source  

SciTech Connect

An experimental program to develop and build a dielectric-based slab-symmetric structure (the micro-accelerator platform, or MAP) for generating and accelerating low-energy electrons is underway at UCLA and Manhattanville College. This optical acceleration structure is effectively a resonant cavity powered by a side-coupled laser, and has applications as a radiation source for medicine or industry. We present recent experimental and computational results on the accelerator, and progress toward its incorporation into a self-contained particle source. Such a particle source would incorporate a micron-scale electron emitter and a non-relativistic capture region to enable self-injection into the synchronous field within the accelerator. A prototype of the accelerator itself has been constructed from candidate dielectric materials using micromanufacturing techniques; the current status of the testing program is described. A novel electron emitter incorporating pyroelectric crystals with field-enhancing tips has been demonstrated to produce steady currents; the results are dependent on tip geometry, and appear suitable for injection into a microstructure. Extension of the MAP concept to non-relativistic velocities, as in the stand-alone source, requires a tapered structure that gives rise to numerous complications including beam defocusing and manufacturing challenges; approaches for addressing these complications are mentioned.

Yoder, R. B. [Dept. of Physics, Manhattanville College, Purchase, NY 10577 (United States); Travish, G.; Arab, E. R.; Fong, D.; Hoyer, Z.; Lacroix, U. H.; Vartanian, N.; Rosenzweig, J. B. [UCLA Dept. of Physics and Astronomy, Los Angeles, CA 90095-1547 (United States)

2010-11-04

114

System dynamic model and charging control of lead-acid battery for stand-alone solar PV system  

SciTech Connect

The lead-acid battery which is widely used in stand-alone solar system is easily damaged by a poor charging control which causes overcharging. The battery charging control is thus usually designed to stop charging after the overcharge point. This will reduce the storage energy capacity and reduce the service time in electricity supply. The design of charging control system however requires a good understanding of the system dynamic behaviour of the battery first. In the present study, a first-order system dynamics model of lead-acid battery at different operating points near the overcharge voltage was derived experimentally, from which a charging control system based on PI algorithm was developed using PWM charging technique. The feedback control system for battery charging after the overcharge point (14 V) was designed to compromise between the set-point response and the disturbance rejection. The experimental results show that the control system can suppress the battery voltage overshoot within 0.1 V when the solar irradiation is suddenly changed from 337 to 843 W/m{sup 2}. A long-term outdoor test for a solar LED lighting system shows that the battery voltage never exceeded 14.1 V for the set point 14 V and the control system can prevent the battery from overcharging. The test result also indicates that the control system is able to increase the charged energy by 78%, as compared to the case that the charging stops after the overcharge point (14 V). (author)

Huang, B.J.; Hsu, P.C.; Wu, M.S.; Ho, P.Y. [New Energy Center, Department of Mechanical Engineering, National Taiwan University, Taipei (China)

2010-05-15

115

Optimum design of a hybrid Photovoltaic\\/Fuel Cell energy system for stand-alone applications  

Microsoft Academic Search

This paper introduces hybrid photovoltaic\\/fuel cell generation system for a typical domestic load that is not located near the electric grid. In this configuration the combination of a battery, an electrolyser, and a hydrogen storage tank are used as the energy storage system. An energy based modeling has been developed with Matlab\\/Simulink to observe evolution of the system during the

Saeed Jalilzadeh; Ahmad Rohani; Hossein Kord; Mojtaba Nemati

2009-01-01

116

Optimisation of a Small Non Controlled Wind Energy Conversion System for Stand-Alone Applications  

Microsoft Academic Search

This article proposes a method to optimize the design of a small fixed-voltage wind energy conversion system (WECS). The system is composed of commercially available elements which are: a small horizontal axe wind turbine, a one- stage gearbox, a permanent magnet synchronous generator, a diode bridge and a battery bank. As there are no controlled devices on the system, the

Miguel Lopez; Philippe Dessante; Dario Morales; Jean-Claude Vannier; Daniel Sadarnac

117

5 Wp PV module-based stand-alone solar tracking system  

Microsoft Academic Search

5 Watt-PV module is utilized for tracking solar oven concentrator system with 2.6 kW\\/sub th\\/ capacity and 200 Kg weight. The tracking system follows the sun autonomously in altitude and azimuth using only 5 Watt-peak PV solar module as a tracking energy source. The tracking system is driven by means of two 12 DCV motors of 36 W each, and

J. A. Urbano; Y. Matsumoto; R. Asomoza; F. J. Aceves; A. Sotelo; A. Jacome

2003-01-01

118

Feasibility Study of Stand-Alone PV-Wind-Biomass Hybrid Energy System in Australia  

Microsoft Academic Search

This paper presents a feasibility study of photo- voltaic (PV), wind, biomass and battery storage based hybrid renewable energy (HRE) system providing electricity to residen- tial area in Australia. The system with load of 200 kWh·day ?1 is analyzed through the environmental and economic aspects. The study computes the net present cost (NPC, $), cost of energy (COE, $ ·

Gang Liu; M. G. Rasul; M. T. O. Amanullah; M. M. K. Khan

2011-01-01

119

Interactive multimedia planning support: moving from stand-alone systems to the World Wide Web  

Microsoft Academic Search

In city planning contexts, hypermedia systems have been demonstrated to be engaging tools that make complex information understandable to those who are not technically sophis ticated. This is accomplished through the use of multimedia interfaces that use images, motion, and sound as representational aids. Hypermedia also affords associative linking which allows one to organize and browse related information in a

M J Shiffer

1995-01-01

120

Highly efficient and high-power industrial FELs driven by a compact, stand-alone and zero-boil-off superconducting RF linac  

NASA Astrophysics Data System (ADS)

In order to realize a tunable, highly efficient, high average power, high peak power and ultra-short pulse free-electron laser (FEL) as a Supertool (Laser, Supertool of the 1980s, Ticker & Fields, New Heaven, CT, 1982) of the 21st century, for all, the JAERI FEL group and I have developed an industrial FEL driven by a compact, stand-alone and zero-boil-off superconducting RF linac (Nucl. Instr. and Meth. 445 (2000)183) with an energy-recovery geometry as a conceptual design. Our discussions on the Supertool will cover market requirements for the industrial FELs, some answers from the JAERI compact, stand-alone and zero-boil-off cryostat concept, non-stop cooling, and operational experience over these 9 years, and our discovery of the new, highly efficient, high-power, and ultra-short pulse lasing mode (Phys. Rev. Lett. 86 (2001) 5707), and the energy-recovery geometry.

Minehara, E. J.

2002-05-01

121

Modeling and simulation of a stand-alone photovoltaic system using an adaptive artificial neural network: Proposition for a new sizing procedure  

Microsoft Academic Search

This paper presents an adaptive artificial neural network (ANN) for modeling and simulation of a Stand-Alone photovoltaic (SAPV) system operating under variable climatic conditions. The ANN combines the Levenberg–Marquardt algorithm (LM) with an infinite impulse response (IIR) filter in order to accelerate the convergence of the network. SAPV systems are widely used in renewable energy source (RES) applications and it

A. Mellit; M. Benghanem; S. A. Kalogirou

2007-01-01

122

Voltage and frequency stabilizer based on Fuzzy logic control for three-level NPC converters in stand-alone wind energy systems  

Microsoft Academic Search

The paper proposes a Fuzzy logic approach for controlling three-level NPC converters in stand alone wind energy systems. A key function of this controller is to maintain constant voltage and frequency for customers while maintaining smooth voltage waveform with less filtering requirements. The principle of the proposed Fuzzy controller is based on a modified PI approach in which the error

Ameen Gargoom; Abu Mohammad Osman Haruni; M. E. Haque; M. Negnevitsky

2010-01-01

123

DC bus voltage build up and control in stand-alone wind energy conversion system using direct vector control of SCIM  

Microsoft Academic Search

This paper presents the start up and operation of a stand-alone wind energy conversion system (WECS) using a squirrel cage induction machine (SCIM). The proposed scheme obviates the use of either excitation capacitor or batteries in DC bus. The DC bus comprising of a combination of normal electrolytic capacitor and few super capacitors, is interfaced with the SCIM through a

Samir Hazra; Partha Sarathi Sensarma

2008-01-01

124

Validation of a Stand-Alone Near Infrared Spectroscopy System for Monitoring Cerebral Autoregulation during Cardiac Surgery  

PubMed Central

Background Individualizing arterial blood pressure (ABP) targets during cardiopulmonary bypass (CPB) based on cerebral blood flow (CBF) autoregulation monitoring may provide a more effective means for preventing cerebral hypoperfusion than the current standard of care. Autoregulation can be monitored in real-time with transcranial Doppler (TCD). We have previously demonstrated that near infrared spectroscopy (NIRS) derived regional cerebral oxygen saturation (rScO2) provides a clinically suitable surrogate of CBF for autoregulation monitoring. The purpose of this study was to determine the accuracy of a stand-alone “plug-and-play” investigational system for autoregulation monitoring that uses a commercially available NIRS monitor with TCD methods. Methods TCD monitoring of middle cerebral artery CBF velocity and NIRS monitoring was performed in 70 patients during CPB. Indices of autoregulation were computed by both a personal computer-based system and an investigational prototype NIRS-based monitor. A moving linear correlation coefficient between slow waves of ABP and CBF velocity (mean velocity index, M×) and between ABP and rScO2 (cerebral oximetry index, CO×) were calculated. When CBF is autoregulated, there is no correlation between CBF and ABP; when CBF is dysregulated, M× and CO× approach 1 (i.e., CBF and ABP are correlated). Linear regression and bias analysis was performed between time-averaged values of M× and CO× derived from the personal computer-based system and from CO× measured with the prototype monitor. Values for M× and CO× were categorized in 5 mmHg bins of ABP for each patient. The lower limit of CBF autoregulation) was defined as the ABP where M× incrementally increased to ? 0.4. Results There was correlation and good agreement between CO× derived from the prototype monitor and M× (r=0.510, 95% confidence interval [CI], 0.414 to 0.595, p<0.001; bias -0.07 ± 0.19). The correlation and bias between the personal computer-based CO× and CO× from the prototype NIRS monitor were r=0.957, 95% CI, 0.945 to 0.966, p<0.001 and 0.06±0.06, respectively. The average ABP at the lower limit of autoregulation was 63 ± 11 mmHg (95% prediction interval, 52 to 74 mmHg mmHg). While the mean ABP at the CO×-determined lower limit of autoregulation determined with the prototype monitor was statistically different from that determined by M× (59 ± 9 mmHg, 95% prediction interval, 50 to 68 mmHg, p=0.026), the difference is not likely clinically meaningful. Conclusions Monitoring CBF autoregulation with an investigational stand-alone NIRS monitor is correlated and in good agreement with TCD based methods. Availability of such a device would allow wide-spread autoregulation monitoring as a means of individualizing ABP targets during CPB.

Ono, Masahiro; Zheng, Yueying; Joshi, Brijen; Sigl, Jeffrey C.; Hogue, Charles W.

2013-01-01

125

An Evaluation of the Accuracy and Precision of a Stand-Alone Submersible Continuous Ruminal pH Measurement System1  

Microsoft Academic Search

The objectives of this study were 1) to develop and evaluate the accuracy and precision of a new stand- alone submersible continuous ruminal pH measure- ment system called the Lethbridge Research Centre ruminalpHmeasurementsystem(LRCpH;Experiment 1); 2) to establish the accuracy and precision of a well- documented, previously used continuous indwelling ru- minal pH system (CIpH) to ensure that the new system

G. B. Penner; K. A. Beauchemin; T. Mutsvangwa

2006-01-01

126

Estimation of the potential array output charge in the performance analysis of stand-alone photovoltaic systems without MPPT (Case study: Mediterranean climate)  

SciTech Connect

The potential array output energy, E{sub P}, stated by the Joint Research Centre (JRC) in their European Guidelines for the Assessment of Photovoltaic Plants and the IEC Standard 61724 does not estimate properly the potential array output of stand-alone photovoltaic (SAPV) systems without maximum power point tracker (MPPT) as it is the case for SAPV systems with MPPT and grid connected systems. In this way, the main purpose of this paper is to validate an expression that compromises simplicity and accuracy when estimating the potential array output of SAPV systems without MPPT. This issue can be of high interest to photovoltaic (PV) practitioners and experts as it can improve the analysis performance of this type of systems, helping to discriminate better the different losses in this kind of systems. Furthermore, a study of the array potential estimation through different expressions will be developed in order to evaluate which matches better the array potential output in SAPV system without MPPT. Although the analysis will be focused especially in Mediterranean climates, it will be derived some general conclusions that can be considered in other climates. (author)

Munoz, F.J.; Echbarthi, I.; Nofuentes, G.; Fuentes, M.; Aguilera, J. [Grupo IDEA, Departamento de Ingenieria Electronica y Automatica, Universidad de Jaen, Campus las Lagunillas, 23071 - Jaen (Spain)

2009-11-15

127

Minimization of the energy storage requirements of a stand-alone wind power installation by means of photovoltaic panels  

Microsoft Academic Search

Autonomous wind power systems are among the most interesting and environmentally friendly technological solutions for the electrification of remote consumers. In many cases, however, the battery contribution to the initial or the total operational cost is found to be dominant, discouraging further penetration of the available wind resource. This is basically the case for areas possessing a medium-low wind potential.

J. K. Kaldellis; P. Kostas; A. Filios

2006-01-01

128

A novel stand-alone PV generation system based on variable step size INC MPPT and SVPWM control  

Microsoft Academic Search

The power available at the output of photovoltaic (PV) cells keeps changing with solar irradiation and ambient temperature because PV cells exhibit a nonlinear current-voltage characteristic. So its maximum power point of photovoltaic cells varies with solar irradiation and ambient temperature. Maximum power point tracking (MPPT) techniques are used in PV systems to make full utilization of PV array output

Jiyong Li; Honghua Wang

2009-01-01

129

Implementation of a multiple input converter using fuzzy logic control for a stand-alone photovoltaic system  

Microsoft Academic Search

Photovoltaic (PV) systems are increasingly being used as distributive generation sources for renewable energy despite their low solar energy conversion to the grid. PV modules have nonlinear characteristics that are determined by solar irradiance and temperature which influences the overall output power of the system. To account for these nonlinearities, maximum power point tracking (MPPT) techniques are implemented to boost

Nadia Smith

2012-01-01

130

Operational optimization of a stand-alone hybrid renewable energy generation system based on an improved genetic algorithm  

Microsoft Academic Search

In a hybrid renewable energy power generation system, optimization and control is a challenging task because the behaviors of the system are becoming unpredictable and more complex. After the system is built, optimization and control of its operation is important for utilizing the renewable energy efficiently and economically. In the paper, an improved genetic algorithm is developed for achieving the

J. Zeng; M. Li; J. F. Liu; J. Wu; H. W. Ngan

2010-01-01

131

Real-Time Energy Management of a Stand-Alone Hybrid Wind-Microturbine Energy System Using Particle Swarm Optimization  

Microsoft Academic Search

Energy sustainability of hybrid energy systems is essentially a multiobjective, multiconstraint problem, where the energy system requires the capability to make rapid and robust decisions regarding the dispatch of electrical power produced by generation assets. This process of control for energy system components is known as energy management. In this paper, the application of particle swarm optimization (PSO), which is

S. Ali Pourmousavi; M. Hashem Nehrir; Christopher M. Colson; Caisheng Wang

2010-01-01

132

Design, simulation and economic analysis of a stand-alone reverse osmosis desalination unit powered by wind turbines and photovoltaics  

Microsoft Academic Search

The fresh water shortage is a significant problem in many areas of the world such as deserts, rural areas, Mediterranean countries and islands. However, renewable energy potential in these areas is usually high using solar and wind energy. A desalination unit powered by renewable energy sources is a promising solution for this problem. This paper presents the design of a

Essam Sh. Mohamed; G. Papadakis

2004-01-01

133

39 CFR 122.2 - Stand-alone special services.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Stand-alone special services. 122.2...SPECIAL SERVICES PRODUCTS § 122.2 Stand-alone special services. (a) The...from the time of order receipt within SFS systems, excluding designated postal...

2013-07-01

134

Stand Alone Air Cleaners: Evaluation and Implications  

Microsoft Academic Search

Stand alone (portable) air cleaners may be an efficient means for rapid removal of indoor fine particles, with potential use for shelter-in-place strategies following acts of bio-terrorism. In this study, a screening model was developed to ascertain the potential significance of size-resolved particle removal using portable air cleaners relative to filtration in HVAC systems, deposition to indoor surfaces, and air

Matthew Ward; Jeffrey A. Siegel; Richard L. Corsi

135

Photovoltaic stand-alone applications reading list  

NASA Astrophysics Data System (ADS)

This list of general publications on photovoltaic stand-alone applications was prepared by the Technical Information Branch at the Solar Energy Research Institute (SERI) for the US Department of Energy (DOE) as part of the Solar Technical Information Program. The list provides an introduction to this literature and is not intended to be comprehensive. Although some of the citations refer to grid-connected photovoltaic systems, they contain basic information applicable to stand-alone applications. Many of the technical reports in this reading list result from government contracts with the Jet Propulsion Laboratory, Sandia National Laboratories-Albuquerque, and the Solar Energy Research Institute, or subcontracts from these laboratories to universities and researchers in private industry.

1985-08-01

136

Dynamic modeling, design, and simulation of a combined PEM fuel cell and ultracapacitor system for stand-alone residential applications  

Microsoft Academic Search

The available power generated from a fuel cell (FC) power plant may not be sufficient to meet sustained load demands, especially during peak demand or transient events encountered in stationary power plant applications. An ultracapacitor (UC) bank can supply a large burst of power, but it cannot store a significant amount of energy. The combined use of FC and UC

M. Uzunoglu; M. S. Alam

2006-01-01

137

The Compact Disk-Circulation System Interface at the Tacoma Public Library: Beyond Stand-Alone CD-ROM.  

ERIC Educational Resources Information Center

|Describes the development of a CD-ROM public access catalog (CD-PAC)-circulation system interface at the Tacoma (Washington) Public Library. Cost considerations, advantages and disadvantages, access time, and currency of the CD-PAC are discussed. Sidebars cover CD-ROM and the library market, future technologies, and comparisons of prices for…

Hegarty, Kevin

1988-01-01

138

Evaluation of a stand-alone computer-aided detection system for acute intra-cranial hemorrhage in emergency environments  

NASA Astrophysics Data System (ADS)

Acute intra-cranial hemorrhage (AIH) may result from traumatic brain injury (TBI). Successful management of AIH depends heavily on the speed and accuracy of diagnosis. Timely diagnosis in emergency environments in both civilian and military settings is difficult primarily due to severe time restraints and lack of resources. Often, diagnosis is performed by emergency physicians rather than trained radiologists. As a result, added support in the form of computer-aided detection (CAD) would greatly enhance the decision-making process and help in providing faster and more accurate diagnosis of AIH. This paper discusses the implementation of a CAD system in an emergency environment, and its efficacy in aiding in the detection of AIH.

Fernandez, James; Deshpande, Ruchi; Wang, Ximing; Liu, Brent; Brazaitis, Michael; Munter, Fletcher; Liu, Margaret

2011-03-01

139

Solar photovoltaics: Stand alone applications  

NASA Astrophysics Data System (ADS)

The Lewis Research Center involvement in space photovoltaic research and development and in using photovoltaics for terrestrial applications is described with emphasis on applications in which the normal source of power may be a diesel generator, batteries, or other types of power not connected to a utility grid. Once an application is processed, technology is developed and demonstrated with a user who participates in the cost and furnishes the site. Projects completed related to instruments, communication, refrigeration, and highways, are described as well as warning systems, weather stations, fire lookouts, and village power systems. A commercially available photovoltaic powered electric fence charger is the result of Lewis research and development.

Deyo, J. N.

1980-11-01

140

The Impact of Course Delivery Systems on Student Achievement and Sense of Community: A Comparison of Learning Community versus Stand-Alone Classroom Settings in an Open-Enrollment Inner City Public Community College  

ERIC Educational Resources Information Center

|This study examined the effects of two types of course delivery systems (learning community classroom environments versus stand-alone classroom environments) on the achievement of students who were simultaneously enrolled in remedial and college-level social science courses at an inner city open-enrollment public community college. This study was…

Bandyopadhyay, Pamela

2010-01-01

141

Design of an energy efficient PV stand-alone power supply unit for a residential-based CubeSat ground station  

Microsoft Academic Search

This paper addresses the concern of the lack of reliability; efficiency; and power losses of many photovoltaic standalone power supply systems caused by the different elements of the power supply system and varied power ratings. There exists a need for load demand matching with generator output, and the possible variability of the load which introduces further inefficiency was considered. The

G. M. Mwanyasi; M. Adonis

2012-01-01

142

A novel stand-alone dual stator-winding induction generator with static excitation regulation  

Microsoft Academic Search

On the basis of the new idea of electric power integration, a novel stand-alone dual stator-winding induction generator (DWIG) system is built. In this generator, there are two sets of windings to be embedded in the stator slots. One, referred to as the 12-phase power winding, supplies power to the dc load via a 12-phase bridge rectifier, and the other,

Dong Wang; Weiming Ma; Fei Xiao; Botao Zhang; Dezhi Liu; An Hu

2005-01-01

143

Stand-alone microprobe at Livermore  

SciTech Connect

Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories/California have jointly constructed a new stand-alone microprobe facility. Although the facility was built to develop a method to rapidly locate and determine elemental concentrations of micron scale particulates on various media using PIXE, the facility has found numerous applications in biology and materials science. The facility is located at LLNL and uses a General Ionex Corporation Model 358 duoplasmatron negative ion source, a National Electrostatics Corporation 5SDH-2 tandem accelerator, and an Oxford triplet lens. Features of the system include complete computer control of the beam transport using LabVIEWTM for Macintosh, computer controlled beam collimating and divergence limiting slits, automated sample positioning to micron resolution, and video optics for beam positioning and sample observation. Data collection is accomplished with the simultaneous use of as many as four EG&G Ortec IGLET-XTM X-Ray detectors, digital amplifiers made by X-Ray Instruments and Associates (XIA), and LabVIEWTM for Macintosh acquisition software.

Antolak, A J; Bench, G S; Brown, T A; Frantz, B R; Grant, P G; Morse, D H; Roberts, M L

1998-10-02

144

Assessment of a stand-alone gradual capacity reverse osmosis desalination plant to adapt to wind power availability: A case study  

Microsoft Academic Search

Desalination driven by renewable energies is an interesting technology in isolated coastal areas. Its feasibility and reliability are guaranteed by innumerable designs implemented and experiences carried out, mainly focused on small capacity systems. However, only mature and efficient technologies are suitable for medium or large scale desalination. In the case of seawater desalination, wind-powered reverse osmosis is the most efficient,

Baltasar Peñate; Fernando Castellano; Alejandro Bello; Lourdes García-Rodríguez

2011-01-01

145

Three dimensional Pareto Optimal solution to design a hybrid stand-alone wind\\/PV generation system with hydrogen energy storage using multi-objective Particle Swarm Optimization  

Microsoft Academic Search

A hybrid Wind\\/Photovoltaic\\/hydrogen\\/fuel cell generation system is designed to supply power demand. The major components of the system i.e. wind turbine generators, photovoltaic arrays and DC\\/AC converter may be subjected to failure. Also, solar radiation, wind speed and load data are assumed to be entirely deterministic. The goal of this design is to use a novel multi-objective optimization algorithm to

H. R. Baghaee; G. B. Gharehpetian; A. Kashefi Kaviani

2012-01-01

146

Testing the stand-alone microbeam at Columbia University.  

PubMed

The stand-alone microbeam at Columbia University presents a novel approach to biological microbeam irradiation studies. Foregoing a conventional accelerator as a source of energetic ions, a small, high-specific-activity, alpha emitter is used. Alpha particles emitted from this source are focused using a compound magnetic lens consisting of 24 permanent magnets arranged in two quadrupole triplets. Using a 'home made' 6.5 mCi polonium source, a 1 alpha particle s(-1), 10 microm diameter microbeam can, in principle, be realised. As the alpha source energy is constant, once the microbeam has been set up, no further adjustments are necessary apart from a periodic replacement of the source. The use of permanent magnets eliminates the need for bulky power supplies and cooling systems required by other types of ion lenses and greatly simplifies operation. It also makes the microbeam simple and cheap enough to be realised in any large lab. The Microbeam design as well as first tests of its performance, using an accelerator-based beam are presented here. PMID:17189277

Garty, G; Ross, G J; Bigelow, A W; Randers-Pehrson, G; Brenner, D J

2006-12-21

147

Techno-economic Feasibility Analysis of Stand-alone Renewable Energy Systems (PV\\/bat, Wind\\/bat and Hybrid PV\\/wind\\/bat) in Kerman, Iran  

Microsoft Academic Search

This article presents a feasibility analysis of renewable energy systems for supplying the electrical load requirements of a typical community (50 rural households) in a remote location in Kerman, Iran. The renewable energy systems (photovoltaic\\/battery [PV\\/bat], wind\\/battery [wind\\/bat] and hybrid photovoltaic\\/wind\\/battery [PV\\/wind\\/bat]) considered in the analysis were comprised of different combinations of PV modules and wind energy conversion systems (WECS)

I. Baniasad Askari; M. Ameri

2012-01-01

148

Posterior dynamic stabilization of the lumbar spine with the Accuflex rod system as a stand-alone device: experience in 20 patients with 2-year follow-up  

Microsoft Academic Search

Decompression surgery for lumbar spinal stenosis is a common procedure. After surgery, segmental instability sometimes occurs,\\u000a therefore, different methods for restabilization have been developed. Dynamic stabilization systems have been designed to\\u000a improve segmental stability. In this study, clinical results of patients with lumbar spinal stenosis that underwent decompression\\u000a and stabilization with the Accuflex dynamic system are presented; clinical, radiographic, and

Alejandro Reyes-SanchezBaronZ; Barón Zárate-Kalfópulos; Isabel Ramírez-Mora; Luis Miguel Rosales-Olivarez; Armando Alpizar-Aguirre; Guadalupe Sánchez-Bringas

2010-01-01

149

Posterior dynamic stabilization of the lumbar spine with the Accuflex rod system as a stand-alone device: experience in 20 patients with 2-year follow-up  

PubMed Central

Decompression surgery for lumbar spinal stenosis is a common procedure. After surgery, segmental instability sometimes occurs, therefore, different methods for restabilization have been developed. Dynamic stabilization systems have been designed to improve segmental stability. In this study, clinical results of patients with lumbar spinal stenosis that underwent decompression and stabilization with the Accuflex dynamic system are presented; clinical, radiographic, and magnetic resonance imaging (MRI) findings are fully described. Improvements in all clinical measurements, including visual analog scale for back and leg pain, Oswestry disability index, and SF-36 health status survey were noticed. At a 2-year follow-up, 22.22% of patients required hardware removal due to fatigue while in 83% of them no progression of disk degeneration was observed after implantation of the Accuflex system. Additionally, as demonstrated by the MRI images at follow up, three patients (16%) showed disk rehydration with one grade higher on the Pfirmann classification. Although a relatively high hardware failure was observed (22.22%), the use of the dynamic stabilization system Accuflex posterior to decompression procedures, showed clinical benefits and stopped the degenerative process in 83% the patients.

Reyes-Sanchez, Alejandro; Ramirez-Mora, Isabel; Rosales-Olivarez, Luis Miguel; Alpizar-Aguirre, Armando; Sanchez-Bringas, Guadalupe

2010-01-01

150

Multi-site evaluation of a computer aided detection (CAD) algorithm for small acute intra-cranial hemorrhage and development of a stand-alone CAD system ready for deployment in a clinical environment  

NASA Astrophysics Data System (ADS)

Timely detection of Acute Intra-cranial Hemorrhage (AIH) in an emergency environment is essential for the triage of patients suffering from Traumatic Brain Injury. Moreover, the small size of lesions and lack of experience on the reader's part could lead to difficulties in the detection of AIH. A CT based CAD algorithm for the detection of AIH has been developed in order to improve upon the current standard of identification and treatment of AIH. A retrospective analysis of the algorithm has already been carried out with 135 AIH CT studies with 135 matched normal head CT studies from the Los Angeles County General Hospital/ University of Southern California Hospital System (LAC/USC). In the next step, AIH studies have been collected from Walter Reed Army Medical Center, and are currently being processed using the AIH CAD system as part of implementing a multi-site assessment and evaluation of the performance of the algorithm. The sensitivity and specificity numbers from the Walter Reed study will be compared with the numbers from the LAC/USC study to determine if there are differences in the presentation and detection due to the difference in the nature of trauma between the two sites. Simultaneously, a stand-alone system with a user friendly GUI has been developed to facilitate implementation in a clinical setting.

Deshpande, Ruchi R.; Fernandez, James; Lee, Joon K.; Chan, Tao; Liu, Brent J.; Huang, H. K.

2010-03-01

151

Verification of Computer Sizing of Photovoltaic Power Systems  

Microsoft Academic Search

There are no generally accepted computer sizing programs for stand-alone photovoltaic power systems, including the array and the battery, which have been verified for an extended period of time. In order to test the performance and the reliability of stand-alone photovoltaic power systems a computer sizing program for the solar array and battery has been developed. The program covers both

Arne O. Nilsson; Jan Johnsson; Roberto Marinetto

1985-01-01

152

Instructor-Facilitated vs. Stand-Alone Tactical Game Training.  

National Technical Information Service (NTIS)

Sixty-nine Infantry small unit leaders attending the Basic Non- Commissioned Officer Course (BNCOC) at Fort Benning, Georgia, participated in an experiment that investigated the impact of instructor-facilitated versus stand-alone game training on tactical...

S. A. Beal

2009-01-01

153

Efficient line-connected voltage-conditioner with minimum disturbance transfer to stand-alone mode  

NASA Astrophysics Data System (ADS)

This thesis deals with a novel efficient line-connected voltage-conditioning system (VCS) with minimum disturbance transfer to stand-alone mode. The proposed VCS is used for conditioning a terminal voltage of the critical load on the equipment level. It offers advantages over a conventional rectifier-inverter system in terms of efficiency/harmonic generation and over existing line-connected systems in terms of transfer time/dynamic response. To the author's best knowledge, the concept of a solid-state breaker realized with the controlled turn-on/turn-off switch has been introduced for the first time in this thesis. By using the proposed power converter topology, controller structure independent of the load parameters and line-disturbance detection method, the system conforms to the different susceptibility requirements of the critical equipment. A detailed power circuit and controller description of the proposed current-source-inverter voltage-conditioning system (CSI-VCS) are given. A steady-state analysis of the proposed system is performed including the higher order harmonics. A system controller is designed in order to achieve the two objectives that follow. The first objective is to provide the fast transfer from the line-connected mode to the stand-alone mode in the case of line disturbance. The second objective is to obtain the fast transient response under load disturbance and to provide, in the steady-state, the output voltage of low total harmonic distortion. Proposed is one algorithm for synchronization to the line voltage fully implemented in software. A novel line-voltage. disturbance detection scheme is developed and implemented in software. A 1kVA DSP-controlled laboratory prototype is built to verify the theoretically obtained results. A systematic design procedure and design example are presented and validated using a computer simulation.

Baronijan, Armen

154

Feasibility analysis of stand-alone renewable energy supply options for a large hotel  

Microsoft Academic Search

This paper provides a feasibility analysis of renewable energy supply (RES) for a stand-alone supply large-scale tourist operation (with over 100 beds). The analysis utilises the power load data from a hotel located in a subtropical coastal area of Queensland, Australia. The assessment criteria of the analysis are net present cost, renewable factor and payback time. Due to the limited

G. J. Dalton; D. A. Lockington; T. E. Baldock

2008-01-01

155

Flexible control of small wind turbines with grid failure detection operating in stand-alone and grid-connected mode  

Microsoft Academic Search

This paper presents the development and test of a flexible control strategy for an 11-kW wind turbine with a back-to-back power converter capable of working in both stand-alone and grid-connection mode. The stand-alone control is featured with a complex output voltage controller capable of handling nonlinear load and excess or deficit of generated power. Grid-connection mode with current control is

Remus Teodorescu; Frede Blaabjerg

2004-01-01

156

The Stand-Alone Pressure Measurement Device, a digital memory telemeter for assessing Shuttle structural dynamics  

NASA Astrophysics Data System (ADS)

The Stand-Alone Pressure Measurement Device (SAPMD) is a microminiaturized recorder which has in association with the requisite miniature sensor been used to collect absolute Space Shuttle pressure data over various points of the Orbiter's surface during ascent. The SAPMD is entirely self-contained, incorporating its own sensor, power supply, self-starting sensor, nonvolatile memory for sensor data, and a real-time clock for time reference; it is also sufficiently small, at 6.28 x 1.5 x 0.5 in., to be mounted beneath The Shuttle Orbiter's thermal protection system tiles. Data acquired during Shuttle ascent is recovered after the mission without removal of the SAPMD. Strain gages, vibration gages, and differential pressure gages can be incorporated by the device.

Havey, Gary; Tanji, Todd; Olson, Richard; Wald, Jerry

157

Stand-Alone Computer Courses in Teachers' IT Training  

ERIC Educational Resources Information Center

|The stand-alone computer course is the earliest IT training model in teacher education. Designed in the early 1980s, the course responded to increasing demands from schools that teachers have adequate technology skills. The primary goal was to improve technology proficiency among preservice teachers. Research later determined that student…

Wang, Yu-Mei

2006-01-01

158

Untangling the Confounding Perceptions Regarding the Stand Alone IT Course  

ERIC Educational Resources Information Center

|The stand alone IT/computer course is the earliest IT training model in teacher education programs. This course model has been severely criticized and there has been a call to eliminate it from preservice teachers' IT training. Over the past decade, new IT initiatives were implemented to integrate the computer use throughout teacher training…

Wang, Yu-Mei; Chen, Victor Der-Thanq

2007-01-01

159

Hanford tank initiative cone penetrometer stand alone grouting module  

SciTech Connect

The HTI subsurface characterization task will use the Hanford Cone Penetrometer platform (CPP) to deploy contaminant sensor and soil sampling probes into the vadose zone surrounding SST 241-AX-104. Closure of the resulting penetration holes may be stipulated by WAC requirements. A stand alone grouting capability deployable by the CPP has been developed. This qualification test plan defines testing of this capability to be performed at the Immobilized Low Activity Waste Disposal Complex.

CALLAWAY, W.S.

1998-10-15

160

A six-phase synchronous generator for stand-alone renewable energy generation: Experimental analysis  

Microsoft Academic Search

This paper presents the steady-state behavior of a SPSG (six-phase synchronous generator) configured to operate as a stand-alone electric energy source in conjunction with a hydro power plant. A purely experimental treatment is provided with the emphasis placed on operating regimes that illustrate the advantages of using SPSG. In particular, it is shown that the generator can supply two separate

G. K. Singh

2011-01-01

161

Stand-alone electric-field probe for measurements within enclosures  

Microsoft Academic Search

We propose a stand-alone electric-field probe for realizing electric-field measurements within enclosures that have no slits or holes. The prototype probe has an radio frequency (RF) power detector IC, a programmable IC for storing the electric field measurement data, and a bent monopole antenna printed on a PCB that is mounted in a shielding box. The probe was evaluated using

Hiroki Funato; Takashi Suga

2011-01-01

162

Voltage and Frequency Control of a Stand Alone Brushless Wind Electric Generation Using Generalized Impedance Controller  

Microsoft Academic Search

In this paper, a new strategy for the control of terminal voltage and frequency of a stand-alone self-excited induction generator-(SEIG) based wind generator, working with variable speed and load is proposed. With a generalized impedance controller (GIC) (voltage source pulsewidth-modulated inverter with a dc-link battery), a new strategy to maintain the active and reactive power balance at the SEIG terminals

B. Venkatesa Perumal; Jayanta K. Chatterjee

2008-01-01

163

Performance Prediction of a Stand-Alone Permanent-Magnet Induction Generator  

NASA Astrophysics Data System (ADS)

A permanent-magnet induction generator (PMIG) is a special induction machine self-excited from the inside of the squirrel-cage rotor by a permanent-magnet (PM) rotor. The PMIG can be made to operate as a stand-alone generator when the squirrel-cage rotor is driven by an external prime mover. Moreover, if the capacitors are connected across the stator terminals, adjusting their values can control the output voltage. This paper presents a method for predicting the steady-state performance of such a stand-alone PMIG theoretically. By introducing the per-unit system, a nonlinear equivalent circuit, which can include the variation of the circuit parameters, is derived. Based on this equivalent circuit, the steady-state performance is theoretically calculated, and its validity is confirmed through experiments.

Fukami, Tadashi; Shimizu, Bungo; Hanaoka, Ryoichi; Takata, Shinzo; Miyamoto, Toshio

164

Characteristics of stand-alone microlenses in fiber-based fluorescence imaging applications.  

PubMed

Microlens-ended fibers, which have found tremendous interest in the recent past, find potential biomedical applications, in particular, in endoscopic imaging. The work presented in this paper focuses on the stand-alone microlenses along with custom-fabricated specialty optical fiber, such as imaging fiber, for probe imaging applications. Stand-alone self-aligned microlenses have been fabricated employing microcompression molding and then attached at the end facet of imaging fiber. A detailed characterization of the fabricated microlens is carried and it demonstrates appropriate focusing ability, high fluorescence collection efficiency and imaging ability for biomedical applications. The surface roughness of the microlens is found to be 25 nm with a minimum spot size of 38 ?m. The probe imaging system is found to be able to image the fluorescence microspheres of 10 ?m size. The collection efficiency of the fiber probe with lens found to be enhanced by three times approximately. PMID:21528998

Mirkhalaf, M; Murukeshan, V M; Tor, Shu Beng; Shinoj, V K; Sathiyamoorthy, K

2011-04-01

165

49 CFR 1111.8 - Procedural schedule in stand-alone cost cases.  

Code of Federal Regulations, 2012 CFR

...Procedural schedule in stand-alone cost cases. 1111.8 Section 1111.8 Transportation...Procedural schedule in stand-alone cost cases. (a) Procedural schedule. Absent...schedule will apply in stand-alone cost cases: Day 0âComplaint filed,...

2012-10-01

166

49 CFR 1111.8 - Procedural schedule in stand-alone cost cases.  

Code of Federal Regulations, 2011 CFR

...Procedural schedule in stand-alone cost cases. 1111.8 Section 1111.8 Transportation...Procedural schedule in stand-alone cost cases. (a) Procedural schedule. Absent...schedule will apply in stand-alone cost cases: Day 0âComplaint filed,...

2011-10-01

167

Modeling and simulation of a stand-alone photovoltaic plant with MPPT feature and dedicated battery storage  

Microsoft Academic Search

This paper reports on the modeling and simulation of a stand-alone photovoltaic (PV) plant with maximum power point tracking (MPPT) feature and dedicated battery storage. The overall plant comprises the PV module, battery bank, MPPT module, controller, inverter and a resistive load. The load is supplied by both the PV and the battery bank. The fluctuations in the output of

N. W. Vanden Eynde; S. P. Chowdhury

2010-01-01

168

Optimum photovoltaic angle estimation for stand-alone installations of South Europe on the basis of experimental measurements  

Microsoft Academic Search

South Europe possesses excellent solar potential, setting photovoltaic (PV)-based energy production systems as one of the most promising solutions for covering the electricity needs of remote consumers all around the Mediterranean area. In order to improve the financial performance of similar installations, special attention should be paid in estimating the minimum dimensions of a stand- alone PV-based system, able to

K. A. Kavadias; Chr. Gitersos; D. Zafirakis; J. K. Kaldellis

2011-01-01

169

Stand-alone anterior lumbar discectomy and fusion with plate: initial experience  

Microsoft Academic Search

BackgroundThe stability of the lumbar spine after ALIF with lateral plate fixation and\\/or posterior fixation has previously been investigated; however, stand-alone ALDF with plate has not. Previous clinical studies have demonstrated poor fusion rates with stand-alone anterior interbody fusion in the absence of posterior instrumentation. We review our initial experience with stand-alone ALDF with segmental plate fixation for degenerative disc

Henry E. Aryan; Daniel C. Lu; Frank L. Acosta; Christopher P. Ames

2007-01-01

170

Probabilistic modeling of solar power systems  

Microsoft Academic Search

The author presents a probabilistic approach based on Markov chain theory to model stand-alone photovoltaic power systems and predict their long-term service performance. The major advantage of this approach is that it allows designers and developers of these systems to analyze the system performance as well as the battery subsystem performance in the long run and determine the system design

Fayssal M. Safie

1989-01-01

171

Research on Control Method of Double-Mode Inverter with Grid-Connection and Stand-Alone  

Microsoft Academic Search

Inverter system, as the interface device between the renewable energy system and grid, plays an important role in the distributed generation system. A double-mode single-phase inverter system, which can be operated in grid-connected mode or stand-alone mode with seamless transitions control, is proposed in this paper. The different control strategies applied on the system for the different modes are designed.

Herong Gu; Zilong Yang; Deyu Wang; Weiyang Wu

2006-01-01

172

Photovoltaic \\/ thermal system for stand-alone operation  

Microsoft Academic Search

The growing demand for the utilization of clean energy resources requires consideration of more efficient and economical ways in the usage of available resources and technologies. In the field of solar energy both the efficiency and the economics, i.e. the payback times are crucial questions for a more widespread application of this resource in the future. A novel solution and

Rafael K. Jardan; Istvan Nagy; Angel Cid-Pastor; Ramon Leyva; Abdelali El Aroudi; Luis Martinez-Salamero

2008-01-01

173

Stand alone induction generator with terminal impedance controller and no turbine controls  

Microsoft Academic Search

Induction generators with hydraulic turbines are often used for cogeneration. The same turbine generator configuration can be used for stand-alone generation if an impedance controller is connected to the generator terminals; this configuration requires no hydraulic controls on the turbine. The authors propose an electronic impedance controller to control the voltage and the frequency of a stand-alone induction generator. The

R. Bonert; G. Hoops

1990-01-01

174

A Task-Oriented Framework for Stand-Alone Technology Integration Classes  

ERIC Educational Resources Information Center

|A long-standing challenge for schools of education is how to prepare teachers to effectively integrate technology into classroom instruction. A widespread practice in training preservice teachers is the stand-alone technology class. These classes have evolved over time. This article suggests a further development in stand-alone technology…

Hammond, Thomas C.

2007-01-01

175

The PAMELA experiment: light-nuclei selection with stand-alone detectors  

NASA Astrophysics Data System (ADS)

Launched on the 15th of June 2006, the space experiment PAMELA is providing data showing interesting features in cosmic rays that might change our basic vision of the mechanisms of production, acceleration and propagation of cosmic rays in the galaxy. In addition, PAMELA measurements of cosmic antiproton and positron fluxes are setting strong constraints to the nature of Dark Matter. PAMELA is also testing cosmic rays acceleration and propagation models through precise measurements of light nuclei and their isotopes. The determination of fluxes and secondary-to-primary ratios is possible for nuclei up to Oxygen in the energy range 200MeV/n - 150 GeV/n. To investigate this important item, PAMELA can use measurements from three main detectors: the magnetic spectrometer, the calorimeter and the Time-of-Flight system. Analysis strategy and performance for nuclei studies using the detectors in stand-alone configuration will be discussed in this work.

Carbone, R.; Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Bianco, A.; Boezio, M.; Bogomolov, E. A.; Bonechi, L.; Bongi, M.; Bonvicini, V.; Borisov, S.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Castellini, G.; De Pascale, M. P.; De Santis, C.; De Simone, N.; Di Felice, V.; Formato, V.; Galper, A. M.; Giaccari, U.; Grishantseva, L.; Jerse, G.; Karelin, A. V.; Kheymits, M. D.; Koldashov, S. V.; Y Krutkov, S.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Malvezzi, V.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Menn, W.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Munini, R.; Nikonov, N.; Osteria, G.; Palma, F.; Papini, P.; Pearce, M.; Picozza, P.; Pizzolotto, C.; Ricci, M.; Ricciarini, S. B.; Rossetto, L.; Sarkar, R.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G.; Voronov, S. A.; Wu, J.; Yurkin, Y. T.; Zampa, G.; Zampa, N.; Zverev, V. G.

2013-02-01

176

Voltage regulation of a stand-alone induction generator using thyristor-switched capacitors  

Microsoft Academic Search

Induction generators operating in a stand-alone mode are increasingly being used in isolated areas. Such a generator has very poor voltage regulation. This paper proposes a simple thyristor-switched capacitor (TSC) type voltage regulator for a stand-alone induction generator to maintain voltage within the upper and lower acceptable limits. The capacitor size in each TSC branch is selected very carefully to

M. H. Haque

2008-01-01

177

Power Systems Development Facility, PFBC system perspectives  

Microsoft Academic Search

Southern Company Services (SCS) has investigated the feasibility of constructing a Power Systems Development Facility (PSDF) at the Southem Company`s Clean Coal Research Center in Wilsonville, Alabama. The PSDF combines a number of pilot-scale test facilities at a single site to reduce the overall capital and operating cost compared to individual stand-alone facilities, while continuing the DOE\\/METC`s objective of carrying

G. H. Griswold; T. J. Boyd; M. O. Fankhanel; C. J. Crumm; D. H. Pontius

1993-01-01

178

49 CFR 1109.4 - Mandatory mediation in rate cases to be considered under the stand-alone cost methodology.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Mandatory mediation in rate cases to be considered under the stand-alone...1109.4 Mandatory mediation in rate cases to be considered under the stand-alone...relief from a railroad or railroads in a case involving the stand-alone cost...

2012-10-01

179

49 CFR 1109.4 - Mandatory mediation in rate cases to be considered under the stand-alone cost methodology.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Mandatory mediation in rate cases to be considered under the stand-alone...1109.4 Mandatory mediation in rate cases to be considered under the stand-alone...relief from a railroad or railroads in a case involving the stand-alone cost...

2011-10-01

180

ResLab Performance Testing of Stand-Alone Inverters  

Microsoft Academic Search

ResLab is a testing facility with a range of experience in the testing of Renewable Energy Systems and their components. ResLab also has a key interest in the development of the Renewable Energy Industry and in the improvement of Renewable Energy Systems. This has involved the design of methodologies for testing various systems and their components. One area of interest

N. Dashlooty; N. A. Wilmot; H. Sharma; O. Arteaga; T. L. Pryor

181

An Intelligent Stand-Alone Ultrasonic Device for Monitoring Local Damage Growth in Civil Structures  

NASA Astrophysics Data System (ADS)

For aged, in-service civil structures, continuous structural health monitoring is vital to avoid catastrophic failure. This includes monitoring local damage growth at points crucial to the structure's stability. While traditional ultrasonic devices are well-established for scheduled local human inspections, they are ineligible for continuous monitoring. The objective of this research is to develop a stand-alone, self-contained, compact ultrasonic device for continuous structural health monitoring of civil structures. The battery powered device integrates small ultrasonic transducers with a compact high speed data acquisition and processing unit and a wireless communication device. Rayleigh surface waves, generated by the device, will be used to detect and assess surface cracks. This study, documenting the ongoing development, presents a concept for the functional layout of the ultrasonic device. It also examines a method for the assessment of surface breaking damage using Rayleigh waves in a simulated environment. The examination is under the limitations on power levels that can be supplied by batteries. The ultrasonic device may later be combined with global approaches, like analysis of vibration signals, to increase the sensitivity of damage detection in order to avoid catastrophic failures.

Pertsch, Alexander T.; Kim, Jin-Yeon; Wang, Yang; Jacobs, Laurence J.

2010-02-01

182

NOY: a neutrino observatory network project based on stand alone air shower detector arrays  

NASA Astrophysics Data System (ADS)

We have developed a self powered stand alone particle detector array dedicated to the observation of horizontal tau air showers induced by high energy neutrinos interacting in mountain rock. Air shower particle detection reaches a 100% duty cycle and is practically free of background when compared to Cherenkov light or radio techniques. It is thus better suited for rare neutrino event search. An appropriate mountain to valley topological configuration has been identified and the first array will be deployed on an inclined slope at an elevation of 1500 m facing Southern Alps near the city of Grenoble (France). A full simulation has been performed. A neutrino energy dependent mountain tomography chart is obtained using a neutrino and tau propagation code together with a detailed cartography and elevation map of the region. The array acceptance is then evaluated between 1 PeV and 100 EeV by simulating decaying tau air showers across the valley. The effective detection surface is determined by the shower lateral extension at array location and is hence much larger than the array geometrical area. The array exposure will be 1014 cm2 sr s at 100 PeV. Several independent arrays can be deployed with the aim of constituting a large distributed observatory. Some other sites are already under study. At last, special care is dedicated to the educational and outreach aspects of such a cosmic ray detector.

Montanet, F.; Lebrun, D.; Chauvin, J.; Lagorio, E.; Stassi, P.

2011-09-01

183

An intelligent stand-alone ultrasonic device for monitoring local structural damage: implementation and preliminary experiments  

NASA Astrophysics Data System (ADS)

Continuous structural health monitoring has the potential to significantly improve the safety management of aged, in-service civil structures. In particular, monitoring of local damage growth at hot-spot areas can help to prevent disastrous structural failures. Although ultrasonic nondestructive evaluation (NDE) has proved to be effective in monitoring local damage growth, conventional equipment and devices are usually bulky and only suitable for scheduled human inspections. The objective of this research is to harness the latest developments in embedded hardware and wireless communication for developing a stand-alone, compact ultrasonic device. The device is directed at the continuous structural health monitoring of civil structures. Relying on battery power, the device possesses the functionalities of high-speed actuation, sensing, signal processing, and wireless communication. Integrated with contact ultrasonic transducers, the device can generate 1 MHz Rayleigh surface waves in a steel specimen and measure response waves. An envelope detection algorithm based on the Hilbert transform is presented for efficiently determining the peak values of the response signals, from which small surface cracks are successfully identified.

Pertsch, Alexander; Kim, Jin-Yeon; Wang, Yang; Jacobs, Laurence J.

2011-01-01

184

Control of a stand alone variable speed wind turbine with a permanent magnet synchronous generator  

Microsoft Academic Search

A novel control strategy for the operation of a permanent magnet synchronous generator (PMSG) based stand alone variable speed wind turbine is presented in this paper. The direct drive PMSG is connected to the load through a switch mode rectifier and a vector controlled pulse width modulated (PWM) IGBT-inverter. The generator side switch mode rectifier is controlled to achieve maximum

M. E. Haque; K. M. Muttaqi; M. Negnevitsky

2008-01-01

185

The Boundaries of the Firm: The Choice Between Stand-Alone and Integrated Firms  

Microsoft Academic Search

This study presents a theory of corporate structure selection. It outlines when economic units should be structured as stand-alone firms versus an integrated firm (conglomerate). The theory suggests that an integrated firm better controls agency problems through yardstick competition between managers for project acceptance. However, this structure reduces the ability to receive division-specific project information from the market. Based on

Elazar Berkovitch; Ronen Israel; Efrat Tolkowsky

2006-01-01

186

Developing and Implementing a Stand-Alone Undergraduate Customer Relationship Management (CRM) Course  

Microsoft Academic Search

This paper describes the processes and outcomes undertaken in the pursuit of developing a stand-alone CRM course for undergraduate students enrolled at business schools. The purpose is to fill the current academic resource void on CRM that seems to inhibit schools from offering a CRM course. More specifically, the paper's goal is to aid faculty at those institutions much larger

Douglas J. Lincoln

187

A Fuzzy Voltage Regulator (FVR) for a Stand-alone Synchronous Generator  

Microsoft Academic Search

This study deals with terminal voltage control of a stand-alone synchronous generator using fuzzy logic based controller as a fuzzy voltage regulator (FVR) instead of classical automated voltage regulators (AVR). In order to obtain the simulated behavior of the synchronous machine more accurately, a dq axis transformation based model is preferred instead of reduced and linearized small signal models widely

Mehmet Kubilay Eker; Ismail H. Altas

2007-01-01

188

The operation of a stand-alone, single-phase induction generator using a single-phase, pulse-width modulated inverter with a battery supply  

Microsoft Academic Search

The steady-state and dynamic operation of a novel stand-alone, single-phase induction generator scheme is presented in which the load voltage and frequency are controlled by a single-phase, full-bridge, bipolar pulse-width modulated DC\\/AC inverter. A battery feeding the inverter supplies real power to the generator when the load demand is greater than the power supplied by the prime mover. When the

Olorunfemi Ojo; Obasohan Omozusi; Antonio Ginart; Ben Gonoh

1999-01-01

189

Against the stand-alone-cost test in U.S. freight rail regulation  

Microsoft Academic Search

The stand-alone-cost test has become an expensive, extensive, and time-consuming component of the regulatory practice of the\\u000a U.S. Surface Transportation Board in the performance of its statutory duty to protect “captive shippers” from monopoly rail\\u000a rates. A close examination of the history of its adoption and application suggests only a tenuous connection with its claimed\\u000a intellectual foundations. It is time

Russell Pittman

2010-01-01

190

What Drove First Year Premiums in Stand-Alone Medicare Drug Plans?  

Microsoft Academic Search

Medicare's Part D offers heavily subsidized new drug coverage to 22.5 million seniors to date, of whom 16.5 million are in stand-alone drug plans (Department of Health and Human Services, 2006). The government delegated the delivery of the benefit to private insurance companies arguing that market incentives would lead them to provide coverage at the lowest price possible. The massive

Kosali I. Simon; Claudio Lucarelli

2006-01-01

191

Biomechanical stability of five stand-alone anterior lumbar interbody fusion constructs  

Microsoft Academic Search

Anterior lumbar interbody fusion (ALIF) cages are expected to reduce segmental mobility. Current ALIF cages have different\\u000a designs, suggesting differences in initial stability. The objective of this study was to compare the effect of different stand-alone\\u000a ALIF cage constructs and cage-related features on initial segmental stability. Human multi-segmental specimens were tested\\u000a intact and with an instrumented L3\\/4 disc level. Five

Anthony Tsantrizos; Antonios Andreou; Max Aebi; Thomas Steffen

2000-01-01

192

An Intelligent Stand-Alone Ultrasonic Device for Monitoring Local Damage Growth in Civil Structures  

Microsoft Academic Search

For aged, in-service civil structures, continuous structural health monitoring is vital to avoid catastrophic failure. This includes monitoring local damage growth at points crucial to the structure's stability. While traditional ultrasonic devices are well-established for scheduled local human inspections, they are ineligible for continuous monitoring. The objective of this research is to develop a stand-alone, self-contained, compact ultrasonic device for

Alexander T. Pertsch; Jin-Yeon Kim; Yang Wang; Laurence J. Jacobs

2010-01-01

193

AN INTELLIGENT STAND-ALONE ULTRASONIC DEVICE FOR MONITORING LOCAL DAMAGE GROWTH IN CIVIL STRUCTURES  

Microsoft Academic Search

For aged, in-service civil structures, continuous structural health monitoring is vital to avoid catastrophic failure. This includes monitoring local damage growth at points crucial to the structure’s stability. While traditional ultrasonic devices are well-established for scheduled local human inspections, they are ineligible for continuous monitoring. The objective of this research is to develop a stand-alone, self-contained, compact ultrasonic device for

Alexander T. Pertsch; Jin-Yeon Kim; Yang Wang; Laurence J. Jacobs

2010-01-01

194

Stability analysis on the DC Power Distribution System of More Electric Aircraft  

Microsoft Academic Search

The local DC power distribution system (PDS) of a more electric aircraft is one of the cores of the electric power transmission. Generally, the PDS is made up of small power subsystems designed on their own stand-alone operation. But the interaction between the subsystems (sources and loads) induces some problems of stability. This paper compares the different stability behaviours of

H. Zhang; C. Saudemont; B. Robyns; N. Huttin; R. Meuret

2008-01-01

195

Advanced concept for dispersed power supply system using AC modules  

Microsoft Academic Search

A method of for estimating the reliability of new conceptual stand-alone dispersed power supply systems using AC modules with self-contained logic was proposed and system reliability estimated using a yearly scale simulation. The AC module is able to supply AC power on each module and has the flexibility to enable construction of a grid-connected system. Power storage devices were required

Naotaka Okada; Kiyoshi Takigawa

2001-01-01

196

A Review of Wind Energy Based Decentralized Power Generation Systems with New Developments in India  

Microsoft Academic Search

Wind energy based decentralized power generation implies power generation at islands, remote villages or hilly regions either by stand alone wind energy systems or by wind-diesel-solar etc hybrid systems that are not connected to common grid. There is an imperative need to review the past and discuss the present situation in this upcoming field. This paper reviews the research and

P. Sivachandran; P. Venkatesh; N. Kamaraj

2007-01-01

197

Deadbeat-based PI controller for stand-alone single-phase voltage source inverter using battery cell as primary sources  

Microsoft Academic Search

This paper presents a deadbeat-based proportional­ integral (PI) controller for stand-alone single-phase voltage source inverter using battery cell as primary energy sources. The system consists of the lead acid battery, third order Butterworth low pass DC filter and AC filter, H-bridge inverter, step-up transformer, and also a variety of loads as well as its sinusoidal pulse-width­ modulation (SPWM) deadbeat-based PI

Tiang Tow Leong; Dahaman Ishak

2011-01-01

198

Study of shallow trench isolation dry etching process using oxide hard mask and KrF photo-resist in 90 nm stand-alone flash device  

Microsoft Academic Search

We investigated that Shallow Trench Isolation (STI) dry etching process using SiO2 hard-mask and KrF photo-resist in 90nm stand-alone flash device. As shrinkage of design rule, the thickness of photo-resist is reduced because of guarantee for process margin in photolithographic process, but the etch process margin is smaller. For the reason, the hard-mask system for etch is needed. Generally, the

Eunsang Cho; Mingon Lee; Dongwon Shin; Sangil Hwang; Sangwook Ryu; Kanghyun Lee

2008-01-01

199

Sleeve Gastrectomy as a Stand-alone Bariatric Operation for Severe, Morbid, and Super Obesity  

PubMed Central

Background: The laparoscopic sleeve gastrectomy (LSG) is emerging as an effective bariatric operation and is especially attractive in high-risk populations. In this study we examine the efficacy of LSG as a stand-alone operation in the veteran population. Methods: This is a retrospective review of consecutive patients who underwent LSG as a stand-alone procedure at the Palo Alto Veterans Affairs medical center with a minimum 12-month follow-up. Results: Of 205 patients undergoing bariatric surgery, 71 patients had a sleeve gastrectomy, 40 of whom had the operation performed at least 12 months previously. Thirty-six (90%) were available for 1-year follow-up, with a mean follow-up duration of 22 months (range: 12–42), a mean body mass index of 48.3 kg/m2, and an 83% male population. Mean percent excess weight loss was 61% at an average of 22 months, with no significant difference between severely obese, morbidly obese, and super obese cohorts. Diabetes remission was seen in 56% of patients, hypertension remission in 51.6%, and obstructive sleep apnea remission in 46.4%, and gastroesophageal reflux disease improved or did not change in 83%. Medication use significantly decreased after surgery. Conclusion: LSG is safe and effective as a stand-alone bariatric operation in the high-risk veteran population. It is effective in severely obese, morbidly obese, and super obese patients. LSG induces remission or improvement in comorbidities of nearly all patients, translating to a decrease in medication use.

Bellatorre, Anna; Bellatorre, Nina

2013-01-01

200

A New Zero-profile Implant for Stand-alone Anterior Cervical Interbody Fusion  

Microsoft Academic Search

Background  Several studies suggest fusion rates are higher with anterior cervical discectomy and fusion procedures if supplemented with\\u000a a plate. However, plates may be associated with higher postoperative morbidity and higher rates of dysphagia. This led to\\u000a the development of a cervical stand-alone cage with integrated fixation for zero-profile segmental stabilization.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  We asked whether this new implant would be associated with

M. Scholz; K. J. Schnake; A. Pingel; R. Hoffmann; F. Kandziora

2011-01-01

201

Improvements and applications of COBRA-TF for stand-alone and coupled LWR safety analyses  

SciTech Connect

The advanced thermal-hydraulic subchannel code COBRA-TF has been recently improved and applied for stand-alone and coupled LWR core calculations at the Pennsylvania State Univ. in cooperation with AREVA NP GmbH (Germany)) and the Technical Univ. of Madrid. To enable COBRA-TF for academic and industrial applications including safety margins evaluations and LWR core design analyses, the code programming, numerics, and basic models were revised and substantially improved. The code has undergone through an extensive validation, verification, and qualification program. (authors)

Avramova, M. [Dept. of Mechanical and Nuclear Engineering, Pennsylvania State Univ., 230 Reber Building, Univ. Park, PA 16802 (United States); Cuervo, D. [Dept. of Nuclear Engineering, Technical Univ. of Madrid, Avda. Areo de la Victoria s/n, 28040 Madrid (Spain); Ivanov, K. [Dept. of Mechanical and Nuclear Engineering, Pennsylvania State Univ., 230 Reber Building, Univ. Park, PA 16802 (United States)

2006-07-01

202

Life-cycle cost comparisons of advanced storage batteries and fuel cells for utility, stand-alone, and electric vehicle applications  

SciTech Connect

This report presents a comparison of battery and fuel cell economics for ten different technologies. To develop an equitable economic comparison, the technologies were evaluated on a life-cycle cost (LCC) basis. The LCC comparison involved normalizing source estimates to a standard set of assumptions and preparing a lifetime cost scenario for each technology, including the initial capital cost, replacement costs, operating and maintenance (O M) costs, auxiliary energy costs, costs due to system inefficiencies, the cost of energy stored, and salvage costs or credits. By considering all the costs associated with each technology over its respective lifetime, the technology that is most economical to operate over any given period of time can be determined. An analysis of this type indicates whether paying a high initial capital cost for a technology with low O M costs is more or less economical on a lifetime basis than purchasing a technology with a low initial capital cost and high O M costs. It is important to realize that while minimizing cost is important, the customer will not always purchase the least expensive technology. The customer may identify benefits associated with a more expensive option that make it the more attractive over all (e.g., reduced construction lead times, modularity, environmental benefits, spinning reserve, etc.). The LCC estimates presented in this report represent three end-use applications: utility load-leveling, stand-alone power systems, and electric vehicles.

Humphreys, K.K.; Brown, D.R.

1990-01-01

203

Classification and Technical Review of DC-AC Inverters for Use in Photovoltaic Power Systems.  

National Technical Information Service (NTIS)

A classification system is presented for stand-alone and utility-interactive dc-to-ac inverters used in photovoltaic systems in the 1-to-100-kVA power range. Additional inverter topologies, noted during the classification process, are introduced. To provi...

E. E. Landsman

1979-01-01

204

Power Systems Development Facility, PFBC system perspectives  

SciTech Connect

Southern Company Services (SCS) has investigated the feasibility of constructing a Power Systems Development Facility (PSDF) at the Southem Company`s Clean Coal Research Center in Wilsonville, Alabama. The PSDF combines a number of pilot-scale test facilities at a single site to reduce the overall capital and operating cost compared to individual stand-alone facilities, while continuing the DOE/METC`s objective of carrying out meaningful systems and component testing for advanced coal-based power generation development. The intent of the PSDF is to provide a flexible test facility that can be used to develop advanced power system components and assess the integration and control issues of these advanced power systems. The facility would provide a resource for rigorous, long-term testing and performance assessment of hot stream cleanup devices in an integrated environment, permitting evaluation of not only the cleanup devices but also other components in an integrated operation.

Griswold, G.H. [Southern Co. Services, Inc., Birmingham, AL (United States); Boyd, T.J. [Electric Power Research Inst., Palo Alto, CA (United States); Fankhanel, M.O. [Kellogg (M.W.) Co. (United States); Crumm, C.J. [Foster Wheeler Corp. (United States); Pontius, D.H. [SRI International, Menlo Park, CA (United States)

1993-09-01

205

Subsidence and Nonunion after Anterior Cervical Interbody Fusion Using a Stand-Alone Polyetheretherketone (PEEK) Cage  

PubMed Central

Background The purposes of the present study are to evaluate the subsidence and nonunion that occurred after anterior cervical discectomy and fusion using a stand-alone intervertebral cage and to analyze the risk factors for the complications. Methods Thirty-eight patients (47 segments) who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage and an autologous cancellous iliac bone graft from June 2003 to August 2008 were enrolled in this study. The anterior and posterior segmental heights and the distance from the anterior edge of the upper vertebra to the anterior margin of the cage were measured on the plain radiographs. Subsidence was defined as ? a 2 mm (minor) or 3 mm (major) decrease of the segmental height at the final follow-up compared to that measured at the immediate postoperative period. Nonunion was evaluated according to the instability being ? 2 mm in the interspinous distance on the flexion-extension lateral radiographs. Results The anterior and posterior segmental heights decreased from the immediate postoperative period to the final follow-up at 1.33 ± 1.46 mm and 0.81 ± 1.27 mm, respectively. Subsidence ? 2 mm and 3 mm were observed in 12 segments (25.5%) and 7 segments (14.9%), respectively. Among the expected risk factors for subsidence, a smaller anteroposterior (AP) diameter (14 mm vs. 12 mm) of cages (p = 0.034; odds ratio [OR], 0.017) and larger intraoperative distraction (p = 0.041; OR, 3.988) had a significantly higher risk of subsidence. Intervertebral nonunion was observed in 7 segments (7/47, 14.9%). Compared with the union group, the nonunion group had a significantly higher ratio of two-level fusion to one-level fusions (p = 0.001). Conclusions Anterior cervical fusion using a stand-alone cage with a large AP diameter while preventing anterior intraoperative over-distraction will be helpful to prevent the subsidence of cages. Two-level cervical fusion might require more careful attention for avoiding nonunion.

Yang, Jae Jun; Yu, Chang Hun; Yeom, Jin Sup; Lee, Jae Hyup; Lee, Choon-Ki

2011-01-01

206

Market Assessment of Photovoltaic Power Systems for Agricultural Applications in Morocco.  

National Technical Information Service (NTIS)

A month-long study in Morocco was aimed at assessing the market potential for stand-alone photovoltaic systems in agriculture and rural service applications. The types of applications considered are those requiring less than 15 kw of power. The applicatio...

H. Steingass I. Asmon

1981-01-01

207

Market Assessment of Photovoltaic Power Systems for Agricultural Applications in Morocco.  

National Technical Information Service (NTIS)

Results of a month-long study in Morocco aimed at assessing the market potential for stand-alone photovoltaic systems in agriculture and rural service applications are presented. The following applications, requiring less than 15 kW of power, are describe...

H. Steingass I. Asmon

1981-01-01

208

A Comparative Biomechanical Analysis of Stand Alone Versus Facet Screw and Pedicle Screw Augmented Lateral Interbody Arthrodesis: An In Vitro Human Cadaveric Model.  

PubMed

STUDY DESIGN:: Cadaveric biomechanical study. OBJECTIVE:: To investigate the kinematic response of a stand-alone lateral lumbar interbody cage compared with supplemental posterior fixation with either facet or pedicle screws after lateral discectomy. SUMMARY OF BACKGROUND DATA:: Lateral interbody fusion is a promising minimally invasive fixation technique for lumbar interbody arthrodesis. The biomechanical stability of stand-alone cage placement compared with supplemental posterior fixation with either facet or bilateral pedicle screws remains unclear. METHODS:: A 6-degree of freedom spine simulator was used to test flexibility in 7 human cadaveric specimens. Flexion-extension, lateral-bending, and axial-rotation were tested in the intact condition, followed by destabilization through a lateral discectomy at L2-L3 and L4-L5. Specimens were then reconstructed at both operative segments in the following sequence: (1) lateral interbody cage placement; (2) either Discovery facet screws or the Viper F2 system using a transfacet-pedicular trajectory randomized to L2-L3 or L4-L5; and (3) removal of facet screw fixation followed by placement of bilateral pedicle screw instrumentation. Acute range of motion (ROM) was quantified and analyzed. RESULTS:: All 4 reconstruction groups, including stand-alone interbody cage placement, bilateral Discovery facet screws, the Viper F2 system, and bilateral pedicle screw-rod stabilization, resulted in a significant decrease in acute ROM in all loading modes tested (P<0.05). There were no significant differences observed between the 4 instrumentation groups (P>0.05). Although not statistically significant, the Viper F2 system resulted in greatest reduction of acute ROM in both flexion-extension and axial rotation versus all other treatments (P>0.05). CONCLUSIONS:: Stand-alone interbody cage placement results in a significant reduction in acute ROM at the operative segment in the absence of posterior supplemental fixation. If added fixation is desired, facet screw placement, including the Viper F2 facet screw system using an integrated compression washer and transfacet-pedicular trajectory, provides similar acute stability to the spinal segment compared with traditional bilateral pedicle screw fixation in the setting of lateral interbody cage deployment. PMID:23381181

Kretzer, Ryan M; Molina, Camilo; Hu, Nianbin; Umekoji, Hidemasa; Baaj, Ali A; Serhan, Hassan; Cunningham, Bryan W

2013-02-01

209

Stand-Alone Lateral Interbody Fusion for the Treatment of Low-Grade Degenerative Spondylolisthesis  

PubMed Central

The purpose of this paper was to investigate the stand-alone lateral interbody fusion as a minimally invasive option for the treatment of low-grade degenerative spondylolisthesis with a minimum 24-month followup. Prospective nonrandomized observational single-center study. 52 consecutive patients (67.6 ± 10?y/o; 73.1% female; 27.4 ± 3.4?BMI) with single-level grade I/II single-level degenerative spondylolisthesis without significant spine instability were included. Fusion procedures were performed as retroperitoneal lateral transpsoas interbody fusions without screw supplementation. The procedures were performed in average 73.2 minutes and with less than 50cc blood loss. VAS and Oswestry scores showed lasting improvements in clinical outcomes (60% and 54.5% change, resp.). The vertebral slippage was reduced in 90.4% of cases from mean values of 15.1% preoperatively to 7.4% at 6-week followup (P < 0.001) and was maintained through 24 months (7.1%, P < 0.001). Segmental lordosis (P < 0.001) and disc height (P < 0.001) were improved in postop evaluations. Cage subsidence occurred in 9/52 cases (17%) and 7/52 cases (13%) spine levels needed revision surgery. At the 24-month evaluation, solid fusion was observed in 86.5% of the levels treated. The minimally invasive lateral approach has been shown to be a safe and reproducible technique to treat low-grade degenerative spondylolisthesis.

Marchi, Luis; Abdala, Nitamar; Oliveira, Leonardo; Amaral, Rodrigo; Coutinho, Etevaldo; Pimenta, Luiz

2012-01-01

210

Stand-alone lateral interbody fusion for the treatment of low-grade degenerative spondylolisthesis.  

PubMed

The purpose of this paper was to investigate the stand-alone lateral interbody fusion as a minimally invasive option for the treatment of low-grade degenerative spondylolisthesis with a minimum 24-month followup. Prospective nonrandomized observational single-center study. 52 consecutive patients (67.6 ± 10 y/o; 73.1% female; 27.4 ± 3.4 BMI) with single-level grade I/II single-level degenerative spondylolisthesis without significant spine instability were included. Fusion procedures were performed as retroperitoneal lateral transpsoas interbody fusions without screw supplementation. The procedures were performed in average 73.2 minutes and with less than 50cc blood loss. VAS and Oswestry scores showed lasting improvements in clinical outcomes (60% and 54.5% change, resp.). The vertebral slippage was reduced in 90.4% of cases from mean values of 15.1% preoperatively to 7.4% at 6-week followup (P < 0.001) and was maintained through 24 months (7.1%, P < 0.001). Segmental lordosis (P < 0.001) and disc height (P < 0.001) were improved in postop evaluations. Cage subsidence occurred in 9/52 cases (17%) and 7/52 cases (13%) spine levels needed revision surgery. At the 24-month evaluation, solid fusion was observed in 86.5% of the levels treated. The minimally invasive lateral approach has been shown to be a safe and reproducible technique to treat low-grade degenerative spondylolisthesis. PMID:22545019

Marchi, Luis; Abdala, Nitamar; Oliveira, Leonardo; Amaral, Rodrigo; Coutinho, Etevaldo; Pimenta, Luiz

2012-04-01

211

Casework application of a stand-alone pentaplex assay of extended-ESS STRs.  

PubMed

Using a stand-alone pentaplex comprising two standard-length short tandem repeats (STRs): D12S391 and D1S1656 plus three mini-STRs: D2S441, D10S1248 and D22S1045, all recently adopted to extend the European Standard Set (ESS) STRs, we have examined the genotyping performance of the new markers in 111 challenging casework samples. Although commercial kits now combine the five new STRs with existing core loci, we found the ESS-pentaplex we developed in-house performed better than both MiniFiler (comprising eight miniaturized STRs) and the NGM kit that includes the new STRs in a 15-marker multiplex. Our findings suggest at least part of the improved sensitivity of recently available ESS STRs can be attributed to the loci themselves as well as applying long-standing, robust primer designs that were first designed for the extended ESS markers by the laboratories that originally developed them. Therefore the ESS-pentaplex provides an ideal adjunct to Identifiler or MiniFiler to allow laboratories to assess the new STRs alongside existing standard loci, measure performance with challenging material and generate population frequency data ahead of a final decision on which additional STRs will extend the reconfigured CODIS core set. PMID:23380509

Barbaro, A; Fernandez-Formoso, L; Phillips, C; Carracedo, A; Lareu, M V

2013-02-04

212

Stand-Alone Ethics, Social Responsibility, and Sustainability Course Requirements: A Snapshot from Australia and New Zealand  

ERIC Educational Resources Information Center

|This article analyzes the extent to which Australian and New Zealand marketing educators use dedicated or stand-alone courses to equip students with alternative views of business. A census of marketing programs in degree-granting universities was conducted. Program brochures were obtained via the Internet and were content analyzed. This study…

Rundle-Thiele, Sharyn R.; Wymer, Walter

2010-01-01

213

Strategies for Becoming Involved in Policy: What Was Learned When Faculty Opposed a Stand-Alone Course in Phonics  

Microsoft Academic Search

Recent involvement in teacher education policy around a proposed stand-alone phonics course in Mississippi revealed important guidelines for researchers aiming to influence policy, including (a) build relationships with policy makers; (b) help to define problems by framing issues and proactively put forth solutions rather than waiting to respond to proposals; (c) avoid dichotomization, but instead work to build common ground;

Devon Brenner

2007-01-01

214

Water Wisdom: 23 Stand-Alone Activities on Water Supply and Water Conservation for High School Students. 2nd Edition.  

ERIC Educational Resources Information Center

This water conservation education program for high schools consists of both stand-alone activities and teacher support materials. Lessons are divided into six broad categories: (1) The Water Cycle; (2) Water and Society; (3) Keeping Water Pure; (4) Visualizing Volumes; (5) The Economics of Water Use; and (6) Domestic Water Conservation. The…

Massachusetts State Water Resources Authority, Boston.

215

Strategies for Becoming Involved in Policy: What Was Learned When Faculty Opposed a Stand-Alone Course in Phonics  

ERIC Educational Resources Information Center

|Recent involvement in teacher education policy around a proposed stand-alone phonics course in Mississippi revealed important guidelines for researchers aiming to influence policy, including (a) build relationships with policy makers; (b) help to define problems by framing issues and proactively put forth solutions rather than waiting to respond…

Brenner, Devon

2007-01-01

216

Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications  

DOEpatents

An illumination source comprising a porous silicon having a source of electrons on the surface and/or interticies thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon.

Tam, Shiu-Wing (Downers Grove, IL)

1998-01-01

217

Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications  

DOEpatents

An illumination source comprising a porous silicon having a source of electrons on the surface and/or interticies thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon.

Tam, Shiu-Wing (Downers Grove, IL)

1997-01-01

218

Radiologic Assessment of Subsidence in Stand-Alone Cervical Polyetheretherketone (PEEK) Cage  

PubMed Central

Objective Aim of study was to find a proper method for assessing subsidence using a radiologic measurement following anterior cervical discectomy and fusion (ACDF) with stand-alone polyetheretherketone (PEEK), Solis™ cage. Methods Forty-two patients who underwent ACDF with Solis™ cage were selected. With a minimum follow-up of 6 months, the retrospective investigation was conducted for 37 levels in 32 patients. Mean follow-up period was 18.9 months. Total intervertebral height (TIH) of two fused vertebral bodies was measured on digital radiographs with built-in software. Degree of subsidence (?TIH) was reflected by the difference between the immediate postoperative and follow-up TIH. Change of postoperative disc space height (CT-MR?TIH) was reflected by the difference between TIH of the preoperative mid-sagittal 2D CT and that of the preoperative mid-sagittal T1-weighted MRI. Results Compared to preoperative findings, postoperative disc height was increased in all cases and subsidence was observed only in 3 cases. For comparison of subsidence and non-subsidence group, TIH and CT-MR?TIH of each group were analyzed. There was no statistically significant difference in TIH and CT-MR?TIH between each group at 4 and 8 weeks, but a difference was observed at the last follow-up TIH (p=0.0497). Conclusion ACDF with Solis™ cage was associated with relatively good radiologic long-term results. Fusion was achieved in 94.5% and subsidence occurred in 8.1% by the radiologic assessment. Statistical analysis reveals that the subsidence seen later than 8 weeks after surgery and the development of subsidence does not correlate statistically with the change of the postoperative disc space height.

Ha, Sung-Kon; Kim, Se-Hoon; Lim, Dong-Jun; Kim, Sang-Dae; Lee, Sang-Kook

2008-01-01

219

A simple mathematical description of an off-grid hybrid solar-wind power generating system  

NASA Astrophysics Data System (ADS)

We give a detailed description of the energy balance equation for a stand-alone hybrid solar-wind power generating system. The dimensions of the power generator and the energy capacity of a buffer battery (used as an energy storage system) are chosen to suit a known consumer's profile. Future applications of the mathematical model developed and analogies with a similar hydrodynamic problem are discussed.

Blasone, M.; Dell'Anno, F.; De Luca, R.; Torre, G.

2013-05-01

220

Biomechanical comparison of a new stand-alone anterior lumbar interbody fusion cage with established fixation techniques – a three-dimensional finite element analysis  

Microsoft Academic Search

BACKGROUND: Initial promise of a stand-alone interbody fusion cage to treat chronic back pain and restore disc height has not been realized. In some instances, a posterior spinal fixation has been used to enhance stability and increase fusion rate. In this manuscript, a new stand-alone cage is compared with conventional fixation methods based on the finite element analysis, with a

Shih-Hao Chen; Ching-Lung Tai; Chien-Yu Lin; Pang-Hsing Hsieh; Weng-Pin Chen

2008-01-01

221

Mathematical modelling and performance evaluation of a stand-alone polycrystalline PV plant with MPPT facility  

Microsoft Academic Search

Photovoltaic (PV) generation has now-a-days proved to be a cost-effective method for renewable power generation with minimum environmental impact. Due to environmental and economic benefits, PV is now being widely deployed as a distributed energy resources (DER) in distributed generation systems or microgrids. Extensive laboratory-based research and simulation studies are being performed for assessing its effectiveness as DER in microgrids.

S. Chowdhury; G. A. Taylor; Y. H. Song

2008-01-01

222

Market assessment of photovoltaic power systems for agricultural applications in Morocco  

Microsoft Academic Search

Results of a month-long study in Morocco aimed at assessing the market potential for stand-alone photovoltaic systems in agriculture and rural service applications are presented. The following applications, requiring less than 15 kW of power, are described: irrigation, cattle watering, refrigeration, crop processing, potable water and educational TV. Telecommunications and transportation signalling applications, descriptions of power and energy use profiles,

H. Steingass; I. Asmon

1981-01-01

223

Optimal unit sizing for a hybrid wind\\/photovoltaic generating system  

Microsoft Academic Search

The application of a hybrid wind\\/photovoltaic (PV) power generating system for utilization as a stand-alone or a network connected system is investigated. The optimum combination of wind and PV generation coupled with battery storage for a stand-alone system has been obtained for a hypothetical site in Montana. Generation and storage units for the hybrid system are properly sized in order

W. Kellogg; M. H. Nehrir; G. Venkataramanan; V. Gerez

1996-01-01

224

Photovoltaic Power Systems and the National Electrical Code: Suggested Practices  

SciTech Connect

This suggested practices manual examines the requirements of the National Electrical Code (NEC) as they apply to photovoltaic (PV) power systems. The design requirements for the balance of systems components in a PV system are addressed, including conductor selection and sizing, overcurrent protection ratings and location, and disconnect ratings and location. PV array, battery, charge controller, and inverter sizing and selection are not covered, as these items are the responsibility of the system designer, and they in turn determine the items in this manual. Stand-alone, hybrid, and utility-interactive PV systems are all covered.

WILES, JOHN

2001-03-01

225

Modeling of photovoltaic power plants  

Microsoft Academic Search

This work deals with methods of design for the appropriate selection of a stand-alone photovoltaic power system for residential application in the absence of utility power supply. For a prescribed power demand design includes the determination of required number of photovoltaic (PV) panels and the proper total size of batteries to store part of the day collected energy for night

Zakaria Anwar Zakaria; Bai-Chao Chen; Mohammed Osman Hassan

2008-01-01

226

Performance of a stand-alone wind-electric ice maker for remote villages  

SciTech Connect

Two ice makers in the 1.1 metric tons per 24 hours (1.2 tons per day) size range were tested to determine their performance when directly coupled to a variable-frequency wind turbine generator. Initial tests were conducted using a dynamometer to simulate to wind to evaluate whether previously determined potential problems were significant and to define basic performance parameters. Field testing in Norman, Oklahoma, was completed to determine the performance of one of the ice makers under real wind conditions. As expected, the ice makers produced more ice at a higher speed than rated, and less ice at a lower speed. Due to the large start-up torque requirement of reciprocating compressors, the ice making system experienced a large start-up current and corresponding voltage drop which required a larger wind turbine that expected to provide the necessary current and voltage. Performance curves for ice production and power consumption are presented. A spreadsheet model was constructed to predict ice production at a user-defined site given the wind conditions for that location. Future work should include long-term performance tests and research on reducing the large start-up currents the system experiences when first coming on line.

Davis, H.C. [National Renewable Energy Lab., Golden, CO (United States); Brandemuehl, M.J. [University of Colorado, Boulder, CO (United States). Joint Center for Energy Management; Bergey, M.L.S. [Bergey Windpower Co., Norman, OK (United States)

1995-01-01

227

Hybrid solar\\/wind power system probabilistic modelling for long-term performance assessment  

Microsoft Academic Search

This paper presents a probabilistic approach based on the convolution technique to assess the long-term performance of a hybrid solar–wind power system (HSWPS) for both stand-alone and grid-linked applications. To estimate energy performance of HSWPS the reliability analysis is performed by the use of the energy index of reliability (EIR) directly related to energy expected not supplied (EENS). Analytical expressions

G. Tina; S. Gagliano; S. Raiti

2006-01-01

228

An explosively driven high-power microwave pulsed power system  

NASA Astrophysics Data System (ADS)

The increased popularity of high power microwave systems and the various sources to drive them is the motivation behind the work to be presented. A stand-alone, self-contained explosively driven high power microwave pulsed power system has been designed, built, and tested at Texas Tech University's Center for Pulsed Power and Power Electronics. The system integrates four different sub-units that are composed of a battery driven prime power source utilizing capacitive energy storage, a dual stage helical flux compression generator as the main energy amplification device, an integrated power conditioning system with inductive energy storage including a fast opening electro-explosive switch, and a triode reflex geometry virtual cathode oscillator as the microwave radiating source. This system has displayed a measured electrical source power level of over 5 GW and peak radiated microwaves of about 200 MW. It is contained within a 15 cm diameter housing and measures 2 m in length, giving a housing volume of slightly less than 39 l. The system and its sub-components have been extensively studied, both as integrated and individual units, to further expand on components behavior and operation physics. This report will serve as a detailed design overview of each of the four subcomponents and provide detailed analysis of the overall system performance and benchmarks.

Elsayed, M. A.; Neuber, A. A.; Dickens, J. C.; Walter, J. W.; Kristiansen, M.; Altgilbers, L. L.

2012-02-01

229

Array-Structure Design Handbook for Stand-Alone Photovoltaic Applications.  

National Technical Information Service (NTIS)

This handbook will permit the user to design a low-cost structure for a variety of photovoltaic system applications under 10 kW. Any presently commercially available photovoltaic modules may be used. Design alternatives are provided for different generic ...

R. C. Didelot

1980-01-01

230

COMPARING UTILITY CONNECTED TO STAND ALONE MICRO-GRIDS: FROM THE VIEWPOINT OF A UTILITY ENGINEER  

SciTech Connect

Project examples of grid connected micro grid & example of grid isolated micro grid: drivers – economic, environmental and financial tools to plan/design modeling software resource options, tools to plan/design generation types, fuel options and services to provide smooth transitions required equipment and software controls minimal expense to maximum functionality, real time operational interfaces, getting it built real world complications and advice. This paper is an attempt to present a broad overview of micro grids, project examples, modeling tools, technology options, practical and business insights to enable those interested in micro-grids to quickly come up to speed on the basics and potentially move forward on their own projects with the tools and resources presented. Knowledge and experience with electrical distribution systems will make such an effort easier.

Hoffman, Michael G.; Russo, Bryan J.

2011-06-23

231

Continuous stand-alone controllable aerosol/cloud droplet dryer for atmospheric sampling  

NASA Astrophysics Data System (ADS)

We describe a general-purpose dryer designed for continuous sampling of atmospheric aerosol, where a specified relative humidity (RH) of the sample flow (lower than the atmospheric humidity) is required. It is often prescribed to measure the properties of dried aerosol, for instance for monitoring networks. The specific purpose of our dryer is to dry cloud droplets (maximum diameter approximately 25 ?m, highly charged, up to 5 × 102 charges). One criterion is to minimise losses from the droplet size distribution entering the dryer as well as on the residual dry particle size distribution exiting the dryer. This is achieved by using a straight vertical downwards path from the aerosol inlet mounted above the dryer, and removing humidity to a dry, closed loop airflow on the other side of a semi-permeable GORE-TEX membrane (total area 0.134 m2). The water vapour transfer coefficient, k, was measured to be 4.6 × 10-7 kg m-2 s-1% RH-1 in the laboratory (temperature 294 K) and is used for design purposes. A net water vapour transfer rate of up to 1.2 × 10-6 kg s-1 was achieved in the field. This corresponds to drying a 5.7 L min-1 (0.35 m3 h-1) aerosol sample flow from 100% RH to 27% RH at 293 K (with a drying air total flow of 8.7 L min-1). The system was used outdoors from 9 May until 20 October 2010, on the mountain Brocken (51.80° N, 10.67° E, 1142 m a.s.l.) in the Harz region in central Germany. Sample air relative humidity of less than 30% was obtained 72% of the time period. The total availability of the measurement system was >94% during these five months.

Sjogren, S.; Frank, G. P.; Berghof, M. I. A.; Martinsson, B. G.

2013-02-01

232

Design and implementation of a stand-alone workstation for stereotaxic neurosurgery  

NASA Astrophysics Data System (ADS)

We have developed a Macintosh II based workstation for stereotaxis neurosurgery. Computed Tomography (CT) and Magnetic Resonance Images (MRI) are displayed in the NIH Image environment, customized to include stereotaxic and image manipulation utilities. To obtain the soft tissue detail of MRI images along with the bone definition and coordinate system of CT images, scans from the same patient are registered globally. A transformation is calculated to align the planes of the MRI images along CT planes, and this is then used to extract a MRI slice to correspond to a CT slice containing the target site. The extracted slice is warped, to correct for local misregistration, using corresponding landmarks in this and the CT image. The composite image, generated by overlaying the two, is used to calculate the Brown- Roberts-Wells stereotaxis frame angle settings needed to access the target. Path planning using reformatted CT slices is available as another option. Experimental validation using patient data has been done. This workstation has all the capabilities of a conventional CT workstation in addition to these stereotaxis routines.

Taneja, Udita; Walker, Cedric F.

1993-07-01

233

Emerging technologies: polymer-free phospholipid encapsulated sirolimus nanocarriers for the controlled release of drug from a stent-plus-balloon or a stand-alone balloon catheter.  

PubMed

Drug-eluting stents have proven to be effective in reducing the risk of late restenosis. In order to achieve a controlled and prolonged release of the antiproliferative agent, current drug-eluting stents utilise various biodegradable as well as non-erodible polymeric blends to coat the stent surface and to serve as drug carriers. The utilisation of polymeric compounds in current drug-eluting stents may eventually limit their performance as well as their clinical applicability due to the potential induction of undesirable local reactions. The development of alternative, polymer-free drug carriers has the potential to overcome some of the limitations of current drug-eluting stent formulations. Moreover, improvements in drug carriers may also result in an expansion of the technological possibilities for other intravascular drug delivery systems, such as metal-free or even implant-free solutions. This article describes the structure and the preclinical validation profile of a novel phospholipid encapsulated sirolimus nanocarrier, used as a coating in two formulations: a coronary stent-plus-balloon system and a stand-alone balloon catheter. The nanoparticles provided a stable, even and homogenous coating to the devices in both formulations. Dose-finding studies allowed the most appropriate identification of the best nanoparticle structure associated with an extremely efficient transfer of drug to all layers of the vessel wall, achieving high tissue concentrations that persisted days after the application, with low systemic drug leaks. PMID:23685303

Lemos, Pedro A; Farooq, Vasim; Takimura, Celso K; Gutierrez, Paulo S; Virmani, Renu; Kolodgie, Frank; Christians, Uwe; Kharlamov, Alexander; Doshi, Manish; Sojitra, Prakash; van Beusekom, Heleen M M; Serruys, Patrick W

2013-05-20

234

Long-term clinical and radiological outcomes following stand-alone PLIF surgery using expandable cylindrical threaded cages in patients with degenerative lumbar spine disease  

Microsoft Academic Search

Purpose  Although posterior lumbar interbody fusion (PLIF) using stand-alone cages was a popular arthrodesis method, the effectiveness\\u000a of using such cages has been questioned. We assessed retrospectively the long-term clinical and radiological outcomes of PLIF\\u000a surgery using stand-alone cages for the treatment of degenerative lumbar spine disease, the incidences of pseudoarthrosis,\\u000a and its risk factors.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Between May 2000 and May 2005,

Jin Hoon Park; Sung Woo Roh

2011-01-01

235

Sensitive detection of black powder by a stand-alone ion mobility spectrometer with an embedded titration region.  

PubMed

Sensitive detection of black powder (BP) by stand-alone ion mobility spectrometry (IMS) is full of challenges. In conventional air-based IMS, overlap between the reactant ion O2(-)(H2O)n peak and the sulfur ion peak occurs severely; and common doping methods, providing alternative reactant ion Cl(-)(H2O)n, would hinder the formation of ionic sulfur allotropes. In this work, an ion mobility spectrometer embedded with a titration region (TR-IMS) downstream from the ionization region was developed for selective and sensitive detection of sulfur in BP with CH2Cl2 as the titration reagent. Sulfur ions were produced via reactions between sulfur molecules and O2(-)(H2O)n ions in the ionization region, and the remaining O2(-)(H2O)n ions that entered the titration region were converted to Cl(-)(H2O)n ions, which avoided the peak overlap as well as the negative effect of CH2Cl2 on sulfur ions. The limit of detection for sulfur was measured to be 5 pg. Furthermore, it was demonstrated that this TR-IMS was qualified for detecting less than 5 ng of BP and other nitro-organic explosives. PMID:23621418

Liang, Xixi; Zhou, Qinghua; Wang, Weiguo; Wang, Xin; Chen, Wendong; Chen, Chuang; Li, Yang; Hou, Keyong; Li, Jinghua; Li, Haiyang

2013-04-29

236

Kinome Render: a stand-alone and web-accessible tool to annotate the human protein kinome tree  

PubMed Central

Human protein kinases play fundamental roles mediating the majority of signal transduction pathways in eukaryotic cells as well as a multitude of other processes involved in metabolism, cell-cycle regulation, cellular shape, motility, differentiation and apoptosis. The human protein kinome contains 518 members. Most studies that focus on the human kinome require, at some point, the visualization of large amounts of data. The visualization of such data within the framework of a phylogenetic tree may help identify key relationships between different protein kinases in view of their evolutionary distance and the information used to annotate the kinome tree. For example, studies that focus on the promiscuity of kinase inhibitors can benefit from the annotations to depict binding affinities across kinase groups. Images involving the mapping of information into the kinome tree are common. However, producing such figures manually can be a long arduous process prone to errors. To circumvent this issue, we have developed a web-based tool called Kinome Render (KR) that produces customized annotations on the human kinome tree. KR allows the creation and automatic overlay of customizable text or shape-based annotations of different sizes and colors on the human kinome tree. The web interface can be accessed at: http://bcb.med.usherbrooke.ca/kinomerender. A stand-alone version is also available and can be run locally.

Barker, Jonathan

2013-01-01

237

Design description of the Schuchuli Village photovoltaic power system  

NASA Astrophysics Data System (ADS)

A stand alone photovoltaic (PV) power system for the village of Schuchuli (Gunsight), Arizona, on the Papago Indian Reservation is a limited energy, all 120 V (d.c.) system to which loads cannot be arbitrarily added and consists of a 3.5 kW (peak) PV array, 2380 ampere-hours of battery storage, an electrical equipment building, a 120 V (d.c.) electrical distribution network, and equipment and automatic controls to provide control power for pumping water into an existing water system; operating 15 refrigerators, a clothes washing machine, a sewing machine, and lights for each of the homes and communal buildings. A solar hot water heater supplies hot water for the washing machine and communal laundry. Automatic control systems provide voltage control by limiting the number of PV strings supplying power during system operation and battery charging, and load management for operating high priority at the expense of low priority loads as the main battery becomes depleted.

Ratajczak, A. F.; Vasicek, R. W.; Delombard, R.

1981-05-01

238

Subtask 3.12 - Small Power Systems  

SciTech Connect

The programmatic goal in advanced power systems is to develop small integrated waste treatment, water purification, and power systems in the range of 20 kW to 20 MW in cooperation with commercial vendors. These systems will be designed to incorporate the advanced technical capabilities of the Energy and Environmental Research Center (EERC) with the latest advancements in vendor-offered hardware and software. The primary objective for the work to be performed under this subtask is to develop a commercialization plan for small power systems, evaluate alternative design concepts, and select practical and economical designs for targeted development in upcoming years. A leading objective for the EERC will be to continue to form strong business partnerships with equipment manufacturers who can commercialize the selected power system and treatment design(s). FY95 activities were focused on collecting information from vendors and evaluating alternative design concepts. This year's activities began with the process of selecting one design for targeted development. A case study was performed to determine if the combination of water and waste treatment with power generation could improve the economics over a stand-alone power generation system.

Sprynczynatyk, C.; Schmidt, L.; Kurz, M.D.; Mann, M.D.; Kjelden, M.

1997-08-01

239

Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States  

EPA Science Inventory

The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

240

Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States. (UNH)  

EPA Science Inventory

The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

241

The SDAWES project: an ambitious R&D prototype for wind-powered desalination  

Microsoft Academic Search

This paper describes the design and operational strategies of an ambitious prototype for a desalination system powered exclusively by wind energy. The system, installed on the island of Gran Canaria, was designed with several objectives in mind: (a) to determine experimentally the feasibility of the stand-alone operation of wind farms isolated from the conventional power grids and supplying energy for

José A. Carta; Jaime González; Vicente Subiela

2004-01-01

242

Outcomes for Elderly Patients with Mental Illness Following Relocation from a Stand-Alone Psychiatric Hospital to Community-Based Extended Care Units  

Microsoft Academic Search

Objective: To assess the outcomes for a group of elderly patients with mental illness following their discharge from a stand-alone psychiatric facility to seven extended care units (ECUs).Method: All patients (n = 60) who were relocated to the ECUs were assessed using a number of standardized clinical and general functioning instruments at 6 months and 6 weeks pre-move, and again

Tom Meehan; Samantha Robertson; Terry Stedman; Gerard Byrne

2004-01-01

243

Regionalized supervisory control and data acquisition system for the Mead-Adelanto project  

Microsoft Academic Search

The Northridge Earthquake proved to the Los Angeles Department of Water & Power that power systems can and will go down. As a result it was decided that a stand-alone, redundant and geographically remote SCADA system should be installed on the transmission system which would have immediate economic payback while increasing system security. By giving us a “second look” the

M. J. LeBlanc; M. Rajabi; D. P. Sweeney

1996-01-01

244

Numerical simulations of a low power microchannel thermal cycling reactor  

Microsoft Academic Search

A roadblock to the development of stand-alone microscale biomedical and chemical analysis systems is the relatively high heating power requirement of the microscale reactors, which typically exceeds the capability of low cost batteries. In this study, a microchannel thermal cycling reactor design using in-channel heating and passive cooling is proposed and a numerical model has been developed. Numerical simulations were

David Erickson; Dongqing Li

2002-01-01

245

77 FR 45606 - Policy Statement Concerning Assistance to Troubled Farm Credit System Institutions  

Federal Register 2010, 2011, 2012, 2013

...to Troubled Farm Credit System (System) Institutions to replace...Policy Statement Concerning Stand- Alone Assistance. The...Assistance to Troubled System Institutions to replace...Policy Statement Concerning Stand-Alone...

2012-08-01

246

Stand-alone cage for posterior lumbar interbody fusion in the treatment of high-degree degenerative disc disease: design of a new device for an "old" technique. A prospective study on a series of 116 patients.  

PubMed

Chronic lumbar pain due to degenerative disc disease affects a large number of people, including those of fully active age. The usual self-repair system observed in nature is a spontaneous attempt at arthrodesis, which in most cases leads to pseudoarthrosis. In recent years, many possible surgical fusion techniques have been introduced; PLIF is one of these. Because of the growing interest in minimally invasive surgery and the unsatisfactory results reported in the literature (mainly due to the high incidence of morbidity and complications), a new titanium lumbar interbody cage (I-FLY) has been developed to achieve solid bone fusion by means of a stand-alone posterior device. The head of the cage is blunt and tapered so that it can be used as a blunt spreader, and the core is small, which facilitates self-positioning. From 2003 to 2007, 119 patients were treated for chronic lumbar discopathy (Modic grade III and Pfirrmann grade V) with I-FLY cages used as stand-alone devices. All patients were clinically evaluated preoperatively and after 1 and 2 years by means of a neurological examination, visual analogue score (VAS) and Prolo Economic and Functional Scale. Radiological results were evaluated by polyaxial computed tomography (CT) scan and flexion-extension radiography. Fusion was defined as the absence of segmental instability on flexion-extension radiography and Bridwell grade I or II on CT scan. Patients were considered clinical "responders" if VAS evaluation showed any improvement over baseline values and a Prolo value >7 was recorded. At the last follow-up examination, clinical success was deemed to have been achieved in 90.5% of patients; the rate of bone fusion was 99.1%, as evaluated by flexion-extension radiography, and 92.2%, as evaluated by CT scan. Morbidity (nerve root injury, dural lesions) and complications (subsidence and pseudoarthrosis) were minimal. PLIF by means of the stand-alone I-FLY cage can be regarded as a possible surgical treatment for chronic low-back pain due to high-degree DDD. This technique is not demanding and can be considered safe and effective, as shown by the excellent clinical and radiological success rates. PMID:21404031

Costa, Francesco; Sassi, Marco; Ortolina, Alessandro; Cardia, Andrea; Assietti, Roberto; Zerbi, Alberto; Lorenzetti, Martin; Galbusera, Fabio; Fornari, Maurizio

2011-03-15

247

Adaptive wide area protection of power systems  

NASA Astrophysics Data System (ADS)

Studies of major blackouts reveal that power system protection devices have contributed to a majority of system disturbances. This leads to efforts of improving protection philosophy. Analysis shows that conventional protection relies on coordination among stand-alone relays to obtain a dependability-biased component-protection scheme. Whereas it is more desirable and also feasible nowadays for an integrated approach to both component and system protection, provided modern relays possessing the ability of sharing information and applying intelligence in decision-making. This dissertation proposes the adaptive protection concept for wide area systems. The scope of the research includes identifying and developing the desired architecture, intelligent algorithms and communication needs that facilitate the protection system to avoid and reduce the impact of system emergencies. The purpose of this research work is to conceptualize and nurture adaptive protection concept for wide area systems, and to conduct feasibility studies to make this concept practically viable. Several case studies are conducted to show the effectiveness of the proposed adaptive protection scheme. In addition, voltage stability, which is a classic wide area problem, can be alleviated with the proposed concept. Steady state and transient simulation studies provided encouraging results. The detailed decision-making algorithms are simulated in several examples for validation of the concept.

Huang, Jiang

248

Power Systems Development Facility. Environmental Assessment  

SciTech Connect

The objective of the PSDF would be to provide a modular facility which would support the development of advanced, pilot-scale, coal-based power systems and hot gas clean-up components. These pilot-scale components would be designed to be large enough so that the results can be related and projected to commercial systems. The facility would use a modular approach to enhance the flexibility and capability for testing; consequently, overall capital and operating costs when compared with stand-alone facilities would be reduced by sharing resources common to different modules. The facility would identify and resolve technical barrier, as well as-provide a structure for long-term testing and performance assessment. It is also intended that the facility would evaluate the operational and performance characteristics of the advanced power systems with both bituminous and subbituminous coals. Five technology-based experimental modules are proposed for the PSDF: (1) an advanced gasifier module, (2) a fuel cell test module, (3) a PFBC module, (4) a combustion gas turbine module, and (5) a module comprised of five hot gas cleanup particulate control devices. The final module, the PCD, would capture coal-derived ash and particles from both the PFBC and advanced gasifier gas streams to provide for overall particulate emission control, as well as to protect the combustion turbine and the fuel cell.

Not Available

1993-06-01

249

Midterm Energy Forecasting System: Stand-Alone Boiler Model Results. Service Report SR/OA/79-04.  

National Technical Information Service (NTIS)

The Council on Wage and Price Stability requested an analysis of the incremental impacts of Fuel Use Act regulations as a function of the stringency of the economic test under which exemptions are granted. To carry out this analysis, EIA utilized both the...

F. H. Murphy J. H. Zalkind

1979-01-01

250

78 FR 65644 - Privacy Act of 1974; System of Records  

Federal Register 2010, 2011, 2012, 2013

...FHFA-OIG may transfer this system of records to a stand-alone, physically secure...FHFA-OIG may transfer this system of records to a stand-alone, physically secure...FHFA-OIG may transfer this system of records to a stand-alone, physically...

2013-11-01

251

POWER SYSTEMS  

Microsoft Academic Search

Low power output of other devices at this time dictates the use of ; nuclear-reactor systems for manned space explorations. Work up to the present is ; briefly reviewed, and progress and utilization of other power supplies are ; discussed. Pros and cons of solar cells, fuel cells, and thermoelectric and ; thermionic devices are included as well as consideration

1962-01-01

252

Single inductor quad-input-dual-output buck converter for photovoltaic systems  

Microsoft Academic Search

Stand-alone photovoltaic (SAPV) system is more favourable than grid connected photovoltaic (PV) system in areas where extension of power grid is impracticable. However, the high set up cost of a SAPV system requires cost efficient solar energy harvesting methods. To improve the energy harvesting efficiency of a PV system, a large, centrally controlled PV array can be rearranged into smaller

K. W. R. Chew; L. Siek

2010-01-01

253

ANALYSIS OF THE TURBULENT HEAT TRANSFER IN SOLAR POWER TOWER MOLTEN SALT RECEIVER TUBE  

Microsoft Academic Search

Central Receiver System (CRS) with molten salt (MS) technology represents the most cost effective and leading candidate technology for electricity generation for stand-alone Solar Power Plants. But MS has a high freezing point, and the tube alloy also can not stand long time with high temperature in MS circumstances. Tube freezing, leaking and salt decomposing are very likely to happen

Chun Chang; Zhifeng Wang; Xin Li; Fengwu Bai; Yong-Heack Kang; Jong-Kyu Kim

254

Economic evaluation of desalination by small-scale autonomous solar-powered membrane distillation units  

Microsoft Academic Search

Solar-powered desalination is an attractive and viable method for the production of fresh water in remote arid areas. One of the most important factors determining desalination decisions is economics. This paper presents an economic assessment performed to estimate the expected water cost, which is the ultimate measure of the feasibility of the stand-alone system. Based on the calculations, the estimated

Fawzi Banat; Nesreen Jwaied

2008-01-01

255

Control of solid oxide fuel cell for stand-alone and grid connection using fuzzy logic technique  

Microsoft Academic Search

Fuel cells are very promising sources of electricity; environmentally safe and very efficient. The fuel cells have numerous applications: houses, industries, hospitals, vehicles etc. Another facet of these fuel cell applications is distributed generation, the implementation of various power generating resources, near the site of need, for reducing reliance on grid power. Fuel cells generate electricity from hydrogen by a

A. R. Sakehare; Asad Davari; Ali Feliachi

2004-01-01

256

49 CFR 232.609 - Handling of defective equipment with ECP brake systems.  

Code of Federal Regulations, 2010 CFR

...freight cars equipped with stand-alone ECP brake systems unless: (1) The...that are equipped with stand-alone ECP brake systems provided all of the following...freight cars equipped with stand-alone ECP brake systems; and (3) The...

2009-10-01

257

49 CFR 232.609 - Handling of defective equipment with ECP brake systems.  

Code of Federal Regulations, 2010 CFR

...freight cars equipped with stand-alone ECP brake systems unless: (1) The...that are equipped with stand-alone ECP brake systems provided all of the following...freight cars equipped with stand-alone ECP brake systems; and (3) The...

2010-10-01

258

Performance enhancement of grid-connected fixed speed wind energy conversion systems (WECS)  

Microsoft Academic Search

Wind power generation is regarded as the most promising of all renewable energy supply to meet the global commitment to climate change. Of all wind power technologies, the fixed speed system employing the rugged squirrel cage induction generators (SCIGs) are the cheapest and simplest for grid connection. While the self excitable induction generator behavior in stand alone circumstances has been

S. Sugiarto; A. Abu-Siada; S. Islam

2009-01-01

259

Modelling and control of standalone solar photovoltaic charging system  

Microsoft Academic Search

The photovoltaic (PV) stand-alone system requires a battery charger for energy storage. This paper presents the modelling and control design of the PV charger system using Buck-Boost converter. The voltage command is determined by both the PV module maximum power point tracking (MPPT) control loop and the battery charging loop. Here the controller is designed so as to balance the

B. Sree Manju; R. Ramaprabha; B. L. Mathur

2011-01-01

260

Adapted multilayer feedforward ANN based power management control of solar photovoltaic and wind integrated power system  

Microsoft Academic Search

This paper proposes a DC linked hybrid solar photovoltaic\\/wind energy system for stand-alone applications. Solar and wind energy are utilized as primary energy sources and battery unit is considered as storage to meet the primary load demand. Loads are considered according to their priority such as primary, deferrable and dump loads. Among these loads primary load is having highest priority.

S. Kumaravel; S. Ashok

2011-01-01

261

A Prospective, Randomized, Controlled Trial Comparing Radiographic and Clinical Outcomes between Stand-Alone Lateral Interbody Lumbar Fusion with either Silicate Calcium Phosphate or rh-BMP2.  

PubMed

Object Iliac crest autograft has traditionally been considered the gold standard for lumbar spine fusion, though it is not without drawbacks related to harvesting site pain and other complications. Bone graft alternatives, such as recombinant human bone morphogenetic protein 2 (rh-BMP2), are now widely used but also have unique risk profiles and substantially increase costs. The purpose of the current study was to compare the efficacy of rh-BMP2 and synthetic silicate calcium phosphate (SiCaP) as bone graft substitutes on fusion rates and clinical outcomes in patients undergoing single-level lumbar stand-alone extreme lateral interbody fusion (XLIF).Methods A prospective, randomized, controlled, clinical, and radiographic study was performed at a single institution. Thirty patients with L4-L5 degenerative disc disease (DDD) were enrolled. Patients were randomized into one of two groups, 15 underwent lumbar single-level stand-alone XLIF using SiCaP, and 15 using rh-BMP2. Clinical and radiographic results were compared between the study groups. Pain (visual analogue scale) and disability (Oswestry disability index) were assessed preoperatively and at postoperative weeks 1 and 6 and postoperative months 3, 6, 12, 24, and 36. Radiographic evaluations were performed at 6, 12, 24, and 36 months. Neurological examinations and adverse events were recorded at each visit.Results No intraoperative complications were observed in either treatment group, and clinical outcomes were similarly improved between bone graft substitutes from baseline to 36 months postoperative. Complications were transient hip flexion weakness (13%), insufficient indirect decompression (7%), subsidence (17%), excessive bone formation (4%), and adjacent segment disease (14%). Complication rates between the groups were similar, though with slightly more instances of subsidence in the SiCaP group and higher rates of excessive bone formation and adjacent segment disease in the rh-BMP2 group. Rates of fusion at different time points were different between the groups, with the SiCaP patients progressing more slowly toward solid fusion. However, at 36 months, 100% of patients undergoing XLIF achieved solid fusion.Conclusions In stand-alone XLIF, SiCaP and rhBMP-2 bone graft substitutes both resulted in complete long-term fusion. rhBMP-2, however, seemed to result in more rapid early postoperative fusion, though with one instance of excessive bone formation in one patient that required subsequent surgical intervention. PMID:23444134

Pimenta, Luiz; Marchi, Luis; Oliveira, Leonardo; Coutinho, Etevaldo; Amaral, Rodrigo

2013-02-26

262

High-Order Sliding Control for a Wind Energy Conversion System Based on a Permanent Magnet Synchronous Generator  

Microsoft Academic Search

This paper presents the output power control of a wind energy conversion system (WECS) based on a permanent magnet synchronous generator (PMSG). It is assumed that the considered wind module integrates a stand-alone hybrid generation system, jointly with a battery bank, a variable ac load, and other generation subsystems. The operation strategy of the hybrid system determines two possible operation

F. Valenciaga; P. F. Puleston

2008-01-01

263

Embedding video in stand alone test equipment to eliminate training for low-volume, high mix manufacturing and field diagnostics  

Microsoft Academic Search

A common problem in supporting system readiness is the training required to operate test and diagnostic systems. Newly enlisted personnel, or multinationals not fluent in English, are often called upon to operate and maintain complex, high-value, low-volume systems with a minimum of training. Cost and availability of highly skilled technicians versus user interface development is frequently a major consideration in

K. K. Johnson

2003-01-01

264

Design considerations for a 48 V fuel cell to split single phase inverter system with ultracapacitor energy storage  

Microsoft Academic Search

Fuel cells are a versatile, renewable energy source that can be used in a wide range of applications. In this paper, topologies for a 10 kW inverter system with a low voltage fuel cell input are evaluated based on simplicity, performance, and cost. This particular fuel cell system is intended for household stand-alone power generation. The inverter proposed has a

Troy A. Nergaard; Jeremy F. Ferrell; Leonard G. Leslie; Jih-Sheng Lai

2002-01-01

265

Minimization of green house gases emission by using hybrid energy system for telephony base station site application  

Microsoft Academic Search

Cellular mobile service is a rapidly expanding and a very competitive business worldwide, including developing countries. This paper proposes that the suitable alternative solution of grid power is the stand-alone PV\\/wind hybrid energy system with diesel generator as a backup for cellular mobile telephony base station site in isolated areas. It is expected that the newly developed and installed system

Pragya Nema; R. K. Nema; Saroj Rangnekar

2010-01-01

266

Field detection of bacillus spore aerosols with stand-alone pyrolysis-gas chromatography and ion mobility spectrometry  

NASA Astrophysics Data System (ADS)

A commercially available, hand-held chemical vapor detector was modified to detect Gram-positive Bacillus subtilis var. globigii spores (BG) in outdoor field scenarios. An Airborne Vapor Monitor (AVM) ion mobility spectrometry (IMS) vapor detector was interfaced to a biological sample processing and transfer introduction system. The biological sample processing was accomplished by quartz tube pyrolysis (Py), and the resultant vapor was transferred by gas chromatography (GC) to the IMS detector. The Py-GC/IMS system can be described as a hyphenated device where two analytical dimensions, in series, allow the separation and isolation of individual components from the pyrolytic decomposition of biological analytes. Gram positive spores such as BG contain 5 - 15% by weight of dipicolinic acid (DPA), and picolinic acid is a pyrolysis product of DPA. Picolinic acid has a high proton affinity, and it is detected in a sensitive fashion by the atmospheric pressure-based IMS device. Picolinic acid occupies a unique region in the GC/IMS data domain with respect to other bacterial pyrolysis products. A 1000 to 1, air-to-air, aerosol concentrator was interfaced to the Py-GC/IMS instrument, and the system was placed in an open-air, Western United States desert environment. The system was tested with BG spore aerosol releases, and the instrument was remotely operated during a trial. A Met-One aerosol particle counter was placed next to the Py-GC/IMS so as to obtain a real-time record of the ambient and bacterial aerosol challenges. The presence/absence of an aerosol event, determined by an aerosol particle counter and a slit sampler-agar plate system, was compared to the presence/absence of a picolinic acid response in a GC/IMS data window at selected times in a trial with respect to a BG challenge. In the 21 BG trials, the Py-GC/IMS instrument experienced two true negatives, no false positives, and the instrument developed a software failure in one trial. The remaining 18 trials were true positive determinations for the presence of BG aerosol, and a limit of detection for the Py-GC/IMS instrument was estimated at approximately 3300 BG spore-containing particles.

Snyder, A. P.; Maswadeh, Waleed M.; Parsons, John A.; Tripathi, Ashish; Meuzelaar, Henk L.; Dworzanski, Jacek P.; Kim, Man-Goo

1999-12-01

267

Use of coronary calcium score scans from stand-alone multislice computed tomography for attenuation correction of myocardial perfusion SPECT  

Microsoft Academic Search

Purpose  To evaluate the use of CT attenuation maps, generated from coronary calcium scoring (CCS) scans at in- and expiration with\\u000a a 64-slice CT scanner, for attenuation correction (AC) of myocardial perfusion SPECT images.\\u000a \\u000a \\u000a \\u000a Methods  Thirty-two consecutive patients underwent 99mTc-tetrofosmin gated adenosine stress\\/rest SPECT scan on an Infinia Hawkeye SPECT-CT device (GE Medical Systems) followed\\u000a by CCS and CT angiography on a

Tiziano Schepis; Oliver Gaemperli; Pascal Koepfli; Christine Rüegg; Cyrill Burger; Sebastian Leschka; Lotus Desbiolles; Lars Husmann; Hatem Alkadhi; Philipp A. Kaufmann

2007-01-01

268

Combined low-cost, high-efficient inverter, peak power tracker and regulator for PV applications  

Microsoft Academic Search

A novel compound power converter that serves as a DC-to-AC inverter, maximum power point tracker (MPPT), and battery charger for stand-alone photovoltaic (PV) power systems is introduced. A theoretical analysis of the proposed converter is performed, and the results are compared with experimental results obtained from a 1.5 kW prototype. The overall cost of PV systems can thus be reduced

J. H. R. Enslin; D. B. Snyman

1991-01-01

269

A regenerative drive for incorporating flywheel energy storage into wind generation systems  

Microsoft Academic Search

The authors describe an asynchronous transmission scheme for a flywheel energy storage unit, which provides a reliable, rugged, but also relatively low-cost interface allowing bidirectional power transfer between the flywheel and the rest of the system. Although operation with stand-alone wind turbines is referred to in particular, the transmission can be readily modified to suit other applications. The configuration forms

T. S. Davies; N. Larsen

1989-01-01

270

Optimum photovoltaic array size for a hybrid wind\\/PV system  

Microsoft Academic Search

A methodology for calculation of the optimum size of a PV array for a stand-alone hybrid wind\\/PV power system is developed. Long term data of wind speed and irradiance recorded for every hour of the day for 30 years were used. These data were used to calculate the probability density functions of the wind speed and the irradiance for each

Bogdan S. Borowy; Ziyad M. Salameh

1994-01-01

271

Optimal dispatch strategy in remote hybrid power systems  

SciTech Connect

For small villages in developing countries, local stand-alone power systems are often more cost-effective than utility grid extension. Various combinations of wind turbine generators, photovoltaic arrays, diesel gensets, and batteries - remote hybrid power systems - may be preferred to diesel-only systems. Dispatch strategy is the aspect of control strategy that pertains to energy flows among components. In systems with both batteries and diesel genset(s), dispatch affects the life-cycle cost through both the fuel usage and the battery life. In this study, dispatch strategies are compared using (1) an analysis of cost trade-offs, (2) a simple, quasi-steady-state time-series model, and finally (3) HYBRID2, a more sophisticated stochastic time-series model. An idealized predictive dispatch strategy, based on assumed perfect knowledge of future load and wind conditions, is developed and used as a benchmark in evaluating simple, non-predictive strategies. The results illustrate the nature of the optimal strategy and indicate that one of two simple diesel dispatch strategies - either load-following or full power for a minimum run time - can, in conjunction with the frugal use of stored energy (the Frugal Discharge Strategy), be virtually as cost-effective as the Ideal Predictive Strategy. The optimal choice of these two simple charging strategies is correlated to three dimensionless parameters, yielding a generalized dispatch design chart for an important class of systems. 30 refs., 17 figs., 3 tabs.

Barley, C.D.; Winn, C.B. [Colorado State Univ., Fort Collins, CO (United States)

1996-10-01

272

Solar-powered, modular, emergency\\/disaster response housing  

Microsoft Academic Search

This paper discusses the use of solar-powered modular housing for nationwide disaster relief. Auburn University has performed a design study that demonstrates its feasibility for a stand-alone power system on 398 ft2 ¿Katrina Cottages¿. As a result of Hurricane Katrina, the concept of a ¿Katrina Cottage¿ to house residents temporarily was funded. They are equipped with energy star appliances and

H. W. Brandhorst; J. A. Rodiek

2009-01-01

273

Market assessment of photovoltaic power systems for agricultural applications worldwide  

NASA Astrophysics Data System (ADS)

Agricultural sector PV market assessments conducted in the Phillippines, Nigeria, Mexico, Morocco, and Colombia are extrapolated worldwide. The types of applications evaluated are those requiring less than 15 kW of power and operate in a stand alone mode. The major conclusions were as follows: PV will be competitive in applications requiring 2 to 3 kW of power prior to 1983; by 1986 PV system competitiveness will extend to applications requiring 4 to 6 kW of power, due to capital constraints, the private sector market may be restricted to applications requiring less than about 2 kW of power; the ultimate purchase of larger systems will be governments, either through direct purchase or loans from development banks. Though fragmented, a significant agriculture sector market for PV exists; however, the market for PV in telecommunications, signalling, rural services, and TV will be larger. Major market related factors influencing the potential for U.S. PV Sales are: lack of awareness; high first costs; shortage of long term capital; competition from German, French and Japanese companies who have government support; and low fuel prices in capital surplus countries. Strategies that may aid in overcoming some of these problems are: setting up of a trade association aimed at overcoming problems due to lack of awareness, innovative financing schemes such as lease arrangements, and designing products to match current user needs as opposed to attempting to change consumer behavior.

Cabraal, A.; Delasanta, D.; Rosen, J.; Nolfi, J.; Ulmer, R.

1981-11-01

274

Microcontroller-based power-angle instrument for a power systems laboratory  

Microsoft Academic Search

This paper presents the design and construction of a microcontroller-based instrument to measure the power angle, the rotor speed, and the terminal voltage frequency of synchronous machines. The instrument is suitable for both steady-state and transient measurements. It can be used as a stand alone instrument or connected to a personal computer. The instrument uses a 256-slit optical encoder and

E. Barrera-Cardiel; N. Pastor-Gomez

1999-01-01

275

Market assessment of photovoltaic power systems for agricultural applications in the Philippines  

NASA Astrophysics Data System (ADS)

The market potential in the Philippines for stand alone photovoltaic (P/V) systems in agriculture was assessed. Applications include: irrigation, postharvest operation, food and fiber processing and storage, and livestock and fisheries operations. Power and energy use profiles for many applications as well as assessments of business, government and financial climate for P/V sales are described. Many characteristics of the Philippine agriculture and energy sector favorably influence the use of P/V systems. However, serious and significant barriers prevent achieving the technically feasible, cost competitive market for P/V systems in the agricultural sector. The reason for the small market is the limited availability capital for financing P/V systems. It is suggested that innovative financing schemes and promotional campaigns should be devised.

Cabraal, R. A.; Delasanta, D.; Burrill, G.

1981-04-01

276

High Power Medium Voltage Electronic Load.  

National Technical Information Service (NTIS)

A Pulse Width Modulation (PWM) type, high power (2Kw) medium voltage (200V) electronic load suitable for operation as a stand alone instrument or as an integral part of a more complex test configuration is described. In stand alone operation, the load pow...

M. Martin H. J. N. Spruijt

1989-01-01

277

Evaluation of a photovoltaic energy mechatronics system with a built-in quadratic maximum power point tracking algorithm  

SciTech Connect

The historically high cost of crude oil price is stimulating research into solar (green) energy as an alternative energy source. In general, applications with large solar energy output require a maximum power point tracking (MPPT) algorithm to optimize the power generated by the photovoltaic effect. This work aims to provide a stand-alone solution for solar energy applications by integrating a DC/DC buck converter to a newly developed quadratic MPPT algorithm along with its appropriate software and hardware. The quadratic MPPT method utilizes three previously used duty cycles with their corresponding power outputs. It approaches the maximum value by using a second order polynomial formula, which converges faster than the existing MPPT algorithm. The hardware implementation takes advantage of the real-time controller system from National Instruments, USA. Experimental results have shown that the proposed solar mechatronics system can correctly and effectively track the maximum power point without any difficulties. (author)

Chao, R.M.; Ko, S.H.; Lin, I.H. [Department of Systems and Naval Mechatronics Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China); Pai, F.S. [Department of Electronic Engineering, National University of Tainan (China); Chang, C.C. [Department of Environment and Energy, National University of Tainan (China)

2009-12-15

278

An Efficient Wind–Photovoltaic Hybrid Generation System Using Doubly Excited Permanent-Magnet Brushless Machine  

Microsoft Academic Search

With ever-increasing concerns on energy issues, the development of renewable energy sources is becoming more and more attractive. This paper first reviews both the wind power and photovoltaic (PV) power generation techniques and their maximum-power-point tracking (MPPT) methods. Then, a new stand-alone wind-PV hybrid generation system is proposed for application to remote and isolated areas. For the wind power generation

Chunhua Liu; K. T. Chau; Xiaodong Zhang

2010-01-01

279

Distributed-dispersed renewable energy systems and novel control strategies  

NASA Astrophysics Data System (ADS)

Renewable green-energy systems are re-emerging as viable economic alternative sources of environmentally safe power generation in place of conventional fossil fuels. In terms of power quality and safety, this research investigates a number of renewable green-energy (wind, photovoltaic and fuel cells) interface schemes and control strategies that ensure maximum energy utilization, voltage and frequency stabilization and minimum impact on the host electric grid systems. The research key objectives are to study efficient and robust renewable energy converter schemes with associated control strategies and validate their operations for both stand-alone and electric utility grid interfacing. The research work investigates both stand-alone and grid connected renewable green-energy utilization schemes with a number of power electronic converter topologies and robust control schemes for both dispersed and hybrid renewable energy systems. Different sample study systems and control strategies are digitally simulated and fully validated using the MATLAB-Simulink-SimPower environment.

Aljankawey, Abdualah S.

280

Power system commonality study  

Microsoft Academic Search

A limited top level study was completed to determine the commonality of power system\\/subsystem concepts within potential lunar and Mars surface power system architectures. A list of power system concepts with high commonality was developed which can be used to synthesize power system architectures which minimize development cost. Examples of potential high commonality power system architectures are given in this

Franklin D. Littman

1992-01-01

281

Photovoltaic systems sizing for Algeria  

Microsoft Academic Search

The purpose of this work is to develop an optimization method applicable to stand-alone photovoltaic systems as a function of its reliability. For a given loss-of-load probability (LLP), there are many combinations of battery capacity and photovoltaic array peak power. The problem consists in determining the couple which corresponds to a minimum total system cost. The method has been applied

A. Hadj Arab; B. Ait Driss; R. Amimeur; E. Lorenzo

1995-01-01

282

Electrical Power Generating System.  

National Technical Information Service (NTIS)

An alternating current power generation system adopted to inject power in an already powered power line is discussed. The power generating system solves to adjustably coup an induction motor, as a generator, to an ac power line wherein the motor and power...

F. J. Nola

1981-01-01

283

Solar powered lighting system  

Microsoft Academic Search

A solar powered lighting system including a light emitting unit electrically connected to a rechargeable power storage unit, a solar powered recharger connected to that power storage unit, means to prevent discharge of that power storage unit through the solar powered recharger, means to prevent overcharging of the power storage unit, means to prevent discharging the power storage unit below

Stackpole

1983-01-01

284

System and Battery Charge Control for PV-Powered AC Lighting Systems  

SciTech Connect

This report reviews a number of issues specific to stand-alone AC lighting systems. A review of AC lighting technology is presented, which discusses the advantages and disadvantages of various lamps. The best lamps for small lighting systems are compact fluorescent. The best lamps for intermediate-size systems are high- or low-pressure sodium. Specifications for battery charging and load control are provided with the goal of achieving lamp lifetimes on the order of 16,000 to 24,000 hours and battery lifetimes of 4 to 5 years. A rough estimate of the potential domestic and global markets for stand-alone AC lighting systems is presented. DC current injection tests were performed on high-pressure sodium lamps and the test results are presented. Finally, a prototype system was designed and a prototype system controller (with battery charger and DC/AC inverter) was developed and built.

Kern, G.

1999-04-01

285

Battery energy storage system for variable speed driven PMSG for wind energy conversion system  

Microsoft Academic Search

There are many loads such as remote villages, islands, etc. that are located far away from the main grid. These loads require stand-alone generating system, which can provide constant voltage and frequency for local electrification. Locally available wind power can be used in such off-grid systems. As the wind speed is variable, an AC-DC-AC conversion system is required to convert

Rajveer Mittal; K. S. Sandhu; D. K. Jain

2010-01-01

286

Secondary power systems  

SciTech Connect

In aeronautical engineering secondary power systems have long played second fiddle to the airframe, the engine, and indeed, the avionics. This collection of papers is thus timely, and its publication by the Institution of Mechanical Engineers appropriate, as secondary power systems in modern aircraft present challenging mechanical engineering problems. In military aircraft demands for electrical and hydraulic power and high pressure air have grown over the past two decades. To these basic needs are added requirements for emergency power, ground power, and independent engine starting. Additionally increased reliability and maintainability is demanded from all secondary power systems. Complete contents: What is a secondary power system. Modern technology secondary power systems for next generation military aircraft; Integrated power units; Secondary power system gearbox; Starting the system - air turbine starters; Auxiliary and emergency power system; Secondary hydraulic power generation; Advanced technology electrical power generation equipment.

Not Available

1985-01-01

287

A system perspective on the heating of detached houses  

Microsoft Academic Search

Primary energy use, emission and the cost of whole energy system chains, from natural resource to end-user, were analysed, in a Swedish context, when heating detached houses. Both electricity-based systems employing heat pumps, boilers, or resistance heaters, and local fuel-based systems (e.g. natural gas, oil and wood fuel) were considered. The base-load electricity was produced in stand-alone power plants using

Leif Gustavsson; Åsa Karlsson

2002-01-01

288

Modeling and simulation of microturbine and renewable energy resources for distributed generation system  

Microsoft Academic Search

This paper presents the modeling, analysis, and simulation results of a hybrid generation system in a stand-alone power supply system. The system includes a microturbine (MT) and inverter-based renewable energy resources. A dynamic model and control system for the MT generator (MTG) and inverter-based renewable energy resources are developed to investigate the load-following performance under different operating conditions. The MTG

Yea-Kuang Chan; Jyh-Cherng Gu

2011-01-01

289

Power system restoration issues  

Microsoft Academic Search

Some of the problems encountered in the three phases of power system restoration (PSR) are described. The three phases are planning for restart and reintegration of the bulk power supply, actions during system degradations for saving and retaining critical sources of power, and restoration when the power system has stabilized at some degraded level. Common concerns found in several PSR

M. M. Adibi; R. J. Kafka

1991-01-01

290

Tropix Power System Architecture.  

National Technical Information Service (NTIS)

This document contains results obtained in the process of performing a power system definition study of the TROPIX power management and distribution system (PMAD). Requirements derived from the PMADs interaction with other spacecraft systems are discussed...

D. B. Manner J. M. Hickman

1995-01-01

291

Dynamic modeling of a photovoltaic hydrogen fuel cell hybrid system  

Microsoft Academic Search

The objective of this paper is to mathematically model a stand-alone renewable power system, referred to as “Photovoltaic–Fuel Cell (PVFC) hybrid system”, which maximizes the use of a renewable energy source. It comprises a photovoltaic generator (PV), a water electrolyzer, a hydrogen tank, and a proton exchange membrane (PEM) fuel cell generator. A multi-domain simulation platform Simplorer is employed to

J. J. Hwang; L. K. Lai; W. Wu; W. R. Chang

2009-01-01

292

Control System for a Diesel Generator and UPS Based Microgrid  

NASA Astrophysics Data System (ADS)

In this paper a microgrid composed of a diesel generator and two uninterruptible power supply systems with separate battery banks is introduced. The microgrid located in three academic buildings of Tallinn University of Technology. A three-level control and monitoring system for the microgrid based on the EtherNet/IP communication network is developed. In addition, a control strategy of the microgrid in the grid-connected and stand-alone mode of operation is proposed.

Palamar, Andriy; Pettai, Elmo; Beldjajev, Viktor

2010-01-01

293

Electrical power generating system  

NASA Astrophysics Data System (ADS)

An alternating current power generation system adopted to inject power in an already powered power line is discussed. The power generating system solves to adjustably coup an induction motor, as a generator, to an ac power line wherein the motor and power line are connected through a triac. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced. The principal application will be for windmill powered generation.

Nola, F. J.

1981-03-01

294

A Pneumatic System for Capturing and Storing Wind Energy in Egypt  

Microsoft Academic Search

This paper suggests a hybrid, vertical configuration of multi-bladed and multi-stage (multi-S) Savonius rotors for capturing and storing wind energy. The intended hybrid design is expected to provide small- or near-medium-sized wind turbine of unique design in terms of the gained energy and speed factors. The whole system is dedicated for stand-alone power plants. Integration of wind power into electricity

E. M. ElBeheiry

2011-01-01

295

Ocean engineering power systems  

Microsoft Academic Search

The text presents basic thermodynamic principles and engineering considerations for ocean power systems. A survey chapter introduces a wide range of applications of power systems in the oceans. Thermodynamic principles and engine cycles are extensively reviewed in the next chapter. Then, chapters on energy sources, thermal power plants, and engineering of specific types of ocean systems are presented. Engineering principles

Carmichael

1974-01-01

296

A Modular Plasma System Combining Ion Thrusters, Inertial Electrostatic Confinement, and Theta Pinch Devices  

Microsoft Academic Search

This system is designed to improve the effectiveness and investigate the synergy between several types of ion thrusters and fusion devices, which have typically been used as stand-alone systems. The experimental apparatus is powered by a 45kV capacitor bank, which can be discharged simultaneously through 2 separate cylindrical copper theta pinch coils. In addition 60kV can be applied to the

Jeffrey E. Norman; David N. Ruzic

1999-01-01

297

Power systems (review of \\  

Microsoft Academic Search

This is a good introductory textbook on the subject of power system dynamic performance and control, and I would recommend it to both students of power system dynamics and practicing engineers. It is well written with a good balance between mathematical rigger and physically insightful discussions. The book provides a good broad coverage of dynamics, stability and control of power

Pouyan Pourbeik

2009-01-01

298

Voltage and frequency control with reduced switch integrated voltage source converter for IAG in wind energy conversion system  

Microsoft Academic Search

This paper deals with a voltage and frequency controller (VFC) of a stand-alone wind energy conversion system using an isolated asynchronous generator (IAG) feeding three-phase four-wire loads. The reference generator currents are estimated using the power balance theory to control the voltage and frequency of IAG system. Two-leg reduced switch integrated voltage source converter (VSC) with a battery energy storage

Bhim Singh; Shailendra Sharma; Ambrish Chandra; K. Al Haddad

2010-01-01

299

NSTX electrical power systems  

Microsoft Academic Search

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. The design of the NSTX electrical power system was

S. Ramakrishnan; C. Neumeyer; R. Hatcher; E. Baker; H. Schneider; W. Reiersen; A. von Halle

1999-01-01

300

Design, fabrication, and certification of advanced modular PV power systems. Final technical progress report  

SciTech Connect

Solar Electric Specialties Company (SES) has completed a two and a half year effort under the auspices of the US Department of Energy (DOE) PVMaT (Photovoltaic Manufacturing Technology) project. Under Phase 4A1 of the project for Product Driven System and Component Technology, the SES contract ``Design, Fabrication and Certification of Advanced Modular PV Power Systems`` had the goal to reduce installed system life cycle costs through development of certified (Underwriters Laboratories or other listing) and standardized prototype products for two of the product lines, MAPPS{trademark} (Modular Autonomous PV Power Supply) and Photogensets{trademark}. MAPPS are small DC systems consisting of Photovoltaic modules, batteries and a charge controller and producing up to about a thousand watt-hours per day. Photogensets are stand-alone AC systems incorporating a generator as backup for the PV in addition to a DC-AC inverter and battery charger. The program tasks for the two-year contract consisted of designing and fabricating prototypes of both a MAPPS and a Photogenset to meet agency listing requirements using modular concepts that would support development of families of products, submitting the prototypes for listing, and performing functionality testing at Sandia and NREL. Both prototypes were candidates for UL (Underwriters Laboratories) listing. The MAPPS was also a candidate for FM (Factory Mutual) approval for hazardous (incendiary gases) locations.

Lambarski, T.; Minyard, G. [Solar Electric Specialties Co., Willits, CA (United States)

1998-10-01

301

Power System Analysis  

NASA Astrophysics Data System (ADS)

Electric power generation that relies on various sources as the primary sources of energy is expected to bring down CO2 emissions levels to support the overall strategy to curb global warming. Accordingly, utilities are moving towards integrating more renewable sources for generation, mostly dispersed, and adopting Smart Grid Technologies for system control. In order to construct, operate, and maintain power systems stably and economically in such background, thorough understanding about the characteristics of power systems and their components is essential. This paper presents modeling and simulation techniques available for the analysis of critical aspects such as thermal capacity, stability, voltage stability, and frequency dynamics, vital for the stable operation of power systems.

Taniguchi, Haruhito

302

Power systems (review of \\  

Microsoft Academic Search

This book covers a variety of issues related to the integration and operation of renewable energy (RE) in power systems. Given the steady increase in demand for electricity, increased interest in protecting the environment and deployment of RE power generation sources, and their increased penetration into the power grid worldwide, the subject book is very timely. Congratulations to the authors!

Hashem Nehrir

2009-01-01

303

Radioisotope powered AMTEC systems  

NASA Astrophysics Data System (ADS)

Alkali metal thermal to electric converter (AMTEC) systems are being developed for high performance spacecraft power systems, including small, general purpose heat source (GPHS) powered systems. Several design concepts have been evaluated for the power range from 75 W to 1 kW. The specific power for these concepts has been found to be as high as 18-20 W/kg and 22 kW/m(exp 3). The projected area, including radiators, has been as low as 0.4 m(exp 2)/kW. AMTEC power systems are extremely attractive, relative to other current and projected power systems, because AMTEC offers high power density, low projected area, and low volume. Two AMTEC cell design types have been identified. A single-tube cell is already under development and a multitube cell design, to provide additional power system gains, has undergone proof-of-principle testing. Solar powered AMTEC (SAMTEC) systems are also being developed, and numerous terrestrial applications have been identified for which the same basic AMTEC cells being developed for radioisotope systems are also suitable.

Ivanenok, Joseph F., III; Sievers, Robert K.

1994-11-01

304

Performance analysis of a directly coupled photovoltaic water-pumping system  

Microsoft Academic Search

The application of a stand-alone directly coupled photovoltaic (PV) electromechanical system for water pumping has increased in remote areas of developing countries. In this work, the performance of a PV-powered dc permanent-magnet (PM) motor coupled with a centrifugal pump has been analyzed at different solar intensities and corresponding cell temperature. The results obtained by experiments are compared with the calculated

Mohanlal Kolhe; J. C. Joshi; D. P. Kothari

2004-01-01

305

Flexible development and test system for 11 kW wind turbine  

Microsoft Academic Search

This paper describes a flexible development platform used to implement and test different control strategies for an 11 kW wind energy conversion system capable of working in both grid-connection and stand-alone operation modes. A dSPACE prototyper is used to implement the control and provide a high degree of flexibility allowing code development in Simulink. A back-to-back power conversion configuration is

Remus Teodorescu; Florin Iov; Frede Blaabjerg

2003-01-01

306

Electrical power generating system  

NASA Astrophysics Data System (ADS)

A power generating system for adjusting coupling an induction motor, as a generator, to an A.C. power line wherein the motor and power line are connected through a triac is described. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced.

Nola, F. J.

1983-06-01

307

Powering a CATV System  

Microsoft Academic Search

A cable television network is becoming more of a communications network than a simple distribution system for entertainment. CATV systems today are carrying data and voice communications as well as the entertainment channels. The power requirements for a communications network are far different than a simple entertainment network and the method of powering the network is considerably different than techniques

Robert J. Plow

1984-01-01

308

Economic assessment of advanced central-receiver solar-thermal power systems: PG and E assessment  

Microsoft Academic Search

The plants evaluated included solar\\/fossil hybrid concepts and solar stand-alone plants with thermal storage. Liquid metal\\/molten salt and combined Brayton\\/Rankine cycle concepts were investigated. The analysis was based on the operation of the Pacific Gas and Electric system with these plants modeled in detail on the system. Sensitivities to insolation site, collector area and thermal storage were investigated. The study

J. T. Day; R. F. Boyle; D. W. Doar

1981-01-01

309

Performance characteristics of 350 kW photovoltaic power system for Saudi Arabian villages  

NASA Astrophysics Data System (ADS)

The program goals, design features, and preliminary performance data for a 350 kW concentrator solar cell array for powering a village in Saudi Arabia are outlined. Main design features include passive array cooling, tolerance of sandstorms and 40 kt winds, cleaning with a water jet, inverter output of 277/480 Vac, 3-phase current, stand alone operation, modular construction, minimum maintenance, and a lifetime of 20 yr. The photovoltaic array subsystem comprises 160 pedestal concentrator arrays with each array consisting of 256 2.25-in. diam solar cells exposed to light transmitted through Fresnel lenses at a concentration of 33 suns. Details of the structure and tracking mechanisms are provided. A battery subsystem serves as a power source in the night, and is able to supply 1100 kWh down to 75% discharge. Back-up power is furnished by four 250 kVA diesel generators. The system has thus far displayed an overall efficiency of 11.91%, in line with design goals.

Khoshaim, B. H.

1982-01-01

310

Market assessment of photovoltaic power systems for agricultural applications in Morocco  

SciTech Connect

A month-long study in Morocco was aimed at assessing the market potential for stand-alone photovoltaic systems in agriculture and rural service applications. The types of applications considered are those requiring less than 15 kw of power. The applications include irrigation, cattle watering, refrigeration, crop processing, potable water and educational TV. Telecommunications and transportation signalling applications were also considered in the course of the study. Power and energy use profiles are described for many applications as well assessments of business environment, government and private sector attitudes towards photovoltaics, and financing. The Moroccan market presents both advantages and disadvantages for American PV manufacturers. The principle advantages are a limited grid, interest in and present use of PV in communications applications, attractive investment incentives and a stated policy favoring American investment. Major disadvantages include lack of government incentives for PV use, general unfamiliarity with PV technology, high first cost of PV, a well-established market network for diesel generators, and difficulty with financing. Given these parameters the market for PV in Morocco during the period of 1981 to 1986, will be relatively small, about 340 kwp. Sectors where the market for PV is likely to be more favorable than for agriculture include: telecommunications, transport signalling and some rural services. The primary market appears to be in the public (i.e., government) rather than private sector, due to financial constraints and the high price of PV relative to conventional power sector.

Steingass, H.; Asmon, I.

1981-09-01

311

Market assessment of photovoltaic power systems for agricultural applications in Morocco  

NASA Astrophysics Data System (ADS)

Results of a month-long study in Morocco aimed at assessing the market potential for stand-alone photovoltaic systems in agriculture and rural service applications are presented. The following applications, requiring less than 15 kW of power, are described: irrigation, cattle watering, refrigeration, crop processing, potable water and educational TV. Telecommunications and transportation signalling applications, descriptions of power and energy use profiles, assessments of business environment, government and private sector attitudes towards photovoltaics, and financing were also considered. The Moroccan market presents both advantages and disadvantages for American PV manufacturers. The principle advantages of the Moroccan market are: a limited grid, interest in and present use of PV in communications applications, attractive investment incentives, and a stated policy favoring American investment. Disadvantages include: lack of government incentives for PV use, general unfamiliarity with PV technology, high first cost of PV, a well-established market network for diesel generators, and difficulty with financing. The market for PV in Morocco (1981-1986), will be relatively small, about 340 kwp. The market for PV is likely to be more favorable in telecommunications, transport signalling and some rural services. The primary market appears to be in the public (i.e., government) rather than private sector, due to financial constraints and the high price of PV relative to conventional power sector.

Steingass, H.; Asmon, I.

1981-09-01

312

49 CFR 236.1015 - PTC Safety Plan content requirements and PTC System Certification.  

Code of Federal Regulations, 2010 CFR

...used in subpart H of this part. (3) Stand-alone. A PTC system proposed on a newly constructed track...method of operations. (4) Mixed systems. If a PTC system combining overlay, stand-alone, vital, or non-vital...

2010-10-01

313

A Low Distortion PWM DC-AC Inverter, with Active Current and Voltage Control, Allowing Line-Interfaced and Stand-Alone Photovoltaic Applications  

Microsoft Academic Search

The energy transfer between a photovoltaic solar panel and the grid can be realized by means of a DC-AC inverter, which is described in this paper. A reliability study of the entire system (i.e. the solar panels and the inverter) shows that the voltage generated by the solar panel matrix has to be low (? 100 V). The stability conditions

1982-01-01

314

Development of a Low-Cost, Stand-Alone Microterminal for Support of Testing and Instruction. Final Report for Period January 1977-February 1978.  

ERIC Educational Resources Information Center

A study was undertaken to develop a microterminal for use in a computer-based instructional system. Objectives were to use new microprocessor technology to produce one terminal that is more effective and efficient than either the management terminal or the plasma type interactive terminal presently in use by the Air Force Advanced Instructional…

Steffen, Dale A.; And Others

315

Power Systems Control Architecture  

SciTech Connect

A diagram provided in the report depicts the complexity of the power systems control architecture used by the national power structure. It shows the structural hierarchy and the relationship of the each system to those other systems interconnected to it. Each of these levels provides a different focus for vulnerability testing and has its own weaknesses. In evaluating each level, of prime concern is what vulnerabilities exist that provide a path into the system, either to cause the system to malfunction or to take control of a field device. An additional vulnerability to consider is can the system be compromised in such a manner that the attacker can obtain critical information about the system and the portion of the national power structure that it controls.

James Davidson

2005-01-01

316

Power systems development facility.  

National Technical Information Service (NTIS)

This report discusses the commissioning and operation of the transport reactor train and associated balance-of-plant equipment at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The transport reactor is an advanced circulati...

1998-01-01

317

Satellite Power System (SPS).  

National Technical Information Service (NTIS)

Potential organizational options for a solar power satellite system (SPS) were investigated. Selection and evaluation criteria were determined to include timeliness, reliability, and adequacy to contribute meaningfully to the U.S. supply; political feasib...

H. G. Edler

1978-01-01

318

NTFD--a stand-alone application for the non-targeted detection of stable isotope-labeled compounds in GC/MS data  

PubMed Central

Summary: Most current stable isotope-based methodologies are targeted and focus only on the well-described aspects of metabolic networks. Here, we present NTFD (non-targeted tracer fate detection), a software for the non-targeted analysis of all detectable compounds derived from a stable isotope-labeled tracer present in a GC/MS dataset. In contrast to traditional metabolic flux analysis approaches, NTFD does not depend on any a priori knowledge or library information. To obtain dynamic information on metabolic pathway activity, NTFD determines mass isotopomer distributions for all detected and labeled compounds. These data provide information on relative fluxes in a metabolic network. The graphical user interface allows users to import GC/MS data in netCDF format and export all information into a tab-separated format. Availability: NTFD is C++- and Qt4-based, and it is freely available under an open-source license. Pre-compiled packages for the installation on Debian- and Redhat-based Linux distributions, as well as Windows operating systems, along with example data, are provided for download at http://ntfd.mit.edu/. Contact: gregstep@mit.edu

Hiller, Karsten; Wegner, Andre; Weindl, Daniel; Cordes, Thekla; Metallo, Christian M.; Kelleher, Joanne K.; Stephanopoulos, Gregory

2013-01-01

319

NSTX Electrical Power Systems  

SciTech Connect

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physic Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. The design of the NSTX electrical power system was tailored to suit the available infrastructure and electrical equipment on site. Components were analyzed to verify their suitability for use in NSTX. The total number of circuits and the location of the NSTX device drove the major changes in the Power system hardware. The NSTX has eleven (11) circuits to be fed as compared to the basic three power loops for TFTR. This required changes in cabling to insure that each cable tray system has the positive and negative leg of cables in the same tray. Also additional power cabling had to be installed to the new location. The hardware had to b e modified to address the need for eleven power loops. Power converters had to be reconnected and controlled in anti-parallel mode for the Ohmic heating and two of the Poloidal Field circuits. The circuit for the Coaxial Helicity Injection (CHI) System had to be carefully developed to meet this special application. Additional Protection devices were designed and installed for the magnet coils and the CHI. The thrust was to making the changes in the most cost-effective manner without compromising technical requirements. This paper describes the changes and addition to the Electrical Power System components for the NSTX magnet systems.

A. Ilic; E. Baker; R. Hatcher; S. Ramakrishnan; et al

1999-12-16

320

Wind power generating system  

SciTech Connect

Normally feathered propeller blades of a wind power generating system unfeather in response to the actuation of a power cylinder that responds to actuating signals. Once operational, the propellers generate power over a large range of wind velocities. A maximum power generation design point signals a feather response of the propellers so that once the design point is reached no increase in power results, but the system still generates power. At wind speeds below this maximum point, propeller speed and power output optimize to preset values. The propellers drive a positive displacement pump that in turn drives a positive displacement motor of the swash plate type. The displacement of the motor varies depending on the load on the system, with increasing displacement resulting in increasing propeller speeds, and the converse. In the event of dangerous but not clandestine problems developing in the system, a control circuit dumps hydraulic pressure from the unfeathering cylinder resulting in a predetermined, lower operating pressure produced by the pump. In the event that a problem of potentially cladestine consequence arises, the propeller unfeathering cylinder immediately unloads. Upon startup, a bypass around the motor is blocked, applying a pressure across the motor. The motor drives the generator until the generator reaches a predetermined speed whereupon the generator is placed in circuit with a utility grid and permitted to motor up to synchronous speed.

Schachle, Ch.; Schachle, E. C.; Schachle, J. R.; Schachle, P. J.

1985-03-12

321

Hydrogenated ZnO core-shell nanocables for flexible supercapacitors and self-powered systems.  

PubMed

Although MnO2 is a promising material for supercapacitors (SCs) due to its excellent electrochemical performance and natural abundance, its wide application is limited by poor electrical conductivity. Inspired by our results that the electrochemical activity and electrical conductivity of ZnO nanowires were greatly improved after hydrogenation, we designed and fabricated hydrogenated single-crystal ZnO@amorphous ZnO-doped MnO2 core-shell nanocables (HZM) on carbon cloth as SC electrodes, showing excellent performance such as areal capacitance of 138.7 mF/cm(2) and specific capacitance of 1260.9 F/g. Highly flexible all-solid-state SCs were subsequently assembled with these novel HZM electrodes using polyvinyl alcohol/LiCl electrolyte. The working devices achieved very high total areal capacitance of 26 mF/cm(2) and retained 87.5% of the original capacitance even after 10?000 charge/discharge cycles. An integrated power pack incorporating series-wound SCs and dye-sensitized solar cells was demonstrated for stand-alone self-powered systems. PMID:23368853

Yang, Peihua; Xiao, Xu; Li, Yuzhi; Ding, Yong; Qiang, Pengfei; Tan, Xinghua; Mai, Wenjie; Lin, Ziyin; Wu, Wenzhuo; Li, Tianqi; Jin, Huanyu; Liu, Pengyi; Zhou, Jun; Wong, Ching Ping; Wang, Zhong Lin

2013-02-07

322

Stand alone biofuel production from algae  

Microsoft Academic Search

In this feature, leading researchers in the field of microbial biotechnology speculate on the technical and conceptual developments that will drive innovative research and open new vistas over the next few years

R. H. Wijffels; M. G. J. Janssen; M. J. Barbosa

2011-01-01

323

A Stand-Alone Interactive Physics Showcase  

ERIC Educational Resources Information Center

|We present a showcase with interactive exhibits of basic physical experiments that constitutes a complementary method for teaching physics and interesting students in physical phenomena. Our interactive physics showcase, shown in Fig. 1, stimulates interest for science by letting the students experience, firsthand, surprising phenomena and…

Pfaff, Daniel; Hagelgans, Anja; Weidemuller, Matthias; Bretzer, Klaus

2012-01-01

324

Proton driver power supply system  

SciTech Connect

This paper describes magnet power supply system for a proposed Proton Driver at Fermilab. The magnet power supply system consists of resonant dipole/quadrupole power supply system, quadrupole tracking, dipole correction (horizontal and vertical) and sextupole power supply systems. This paper also describes preliminary design of the power distribution system supplying 13.8 kV power to all proton Driver electrical systems.

C. Jach and D. Wolff

2002-06-03

325

Effect of Initial Powder Morphology and Thermal and Mechanical Properties of Stand-Alone Plasma-Sprayed 7 wt%Y2O3-ZrO2 Coatings  

SciTech Connect

The effects of starting powder morphology on the thermal and mechanical properties of stand-alone plasma-sprayed 7 wt.% Y{sub 2}O{sub 3}-ZrO{sub 2}(YSZ) coatings were studied. Two powder morphologies were investigated: an agglomerated and sintered powder (referred to presently as 'AS') and a powder manufactured using plasma spheroidization to create hollow spheres (referred to presently as 'HS'). Coatings made from AS powders contained 0.21 wt.% SiO{sub 2} impurity, twice as much as observed in coatings made from HS powders. Properties of coatings made from each powder type were compared in the as-sprayed state and after 50 h heat treatments at temperatures ranging from 1000 to 1400 C. SEM microstructural investigations revealed significant differences in the porosity and distribution of pores in the coatings. In coatings made with AS powders the majority of the high aspect ratio pores were located between lamella (interlamellar porosity). In addition to interlamellar pores, coatings made with HS powders demonstrated 1.5 times more spherical-shaped globular pores by number located within lamella. Globular pores were shown to still exist in coatings made with HS powders after 50 h heat treatments at 1400 C. Archimedes porosity measurements showed that coatings made with AS powders typically contained 4-5% less total porosity than coatings made with HS powders. Thermal conductivity experiments using laser flash showed that there was no difference in the thermal conductivity of coatings made from either powder type in the as-sprayed state despite higher porosity in the coatings made from HS powders. After a 50 h heat treatment at 1000 and 1200 C, coatings made from both powder types still demonstrated statistically similar thermal conductivities. However, after a 50 h heat treatment at 1400 C the thermal conductivity of coatings made from AS powders was found to be 0.3 W/m/K higher than coatings made from HS powders. Microstructural differences in the coatings made from the two powder types that affected sintering rates, including the increased level of SiO{sub 2} impurities and fewer globular pores, were used to explain variations in properties. In uniaxial compression tests on stand-alone samples at 1000, 1100, and 1200 C, coatings made from AS powders typically relaxed more stress than coatings made from HS powders. Differences in coating relaxation became more apparent as the test temperature increased through 1200 C. The higher percentage of impurity SiO{sub 2} in the AS coatings is believed to contribute to increased relaxation via formation of a glassy phase at the grain boundaries which assists grain boundary sliding during elevated temperature deformation.

Ercan, Batur [ORNL; Bowman, Keith [ORNL; Trice, Rodney [ORNL; Wang, Hsin [ORNL; Porter, Wallace D [ORNL

2006-01-01

326

Electrical power generating system  

SciTech Connect

An electrical power generating system includes a prime mover having a throttle control for converting a source of input energy into a mechanical output. The system includes an electrical generator having a plurality of output windings and a field winding for exciting the output windings. The generator is mechanically coupled to the mechanical output of the prime mover. Means are provided for sensing a plurality of parameters related to the performance of the system and further means are provided for converting each of the sensed parameters into a digital signal indicative of the magnitude of the sensed parameter. Additional means are provided responsive to the digital signals for developing a plurality of electrical output signals. The electrical output signals are utilized to control either or both the generator and the prime mover to thereby control the output of the power generating system. The system is further provided with circuits for sensing the phase position of the generator output voltage and current and the voltage in a main electrical power conductor. Accordingly, when the generator output is added to the power in the main power conductors, it is done so in phase. Some of the parameters sensed are generator output voltage , current and frequency, generator field winding current and engine throttle position. A digital logic circuit controls the excitation of the generator field winding to thereby control the generator output voltage and current.

Dimitrios, J.T.; Mezera, J.R.; Phillips, G.R.

1982-03-30

327

Autonomous power system brassboard  

NASA Astrophysics Data System (ADS)

The Autonomous Power System (APS) brassboard is a 20 kHz power distribution system which has been developed at NASA Lewis Research Center, Cleveland, Ohio. The brassboard exists to provide a realistic hardware platform capable of testing artificially intelligent (AI) software. The brassboard's power circuit topology is based upon a Power Distribution Control Unit (PDCU), which is a subset of an advanced development 20 kHz electrical power system (EPS) testbed, originally designed for Space Station Freedom (SSF). The APS program is designed to demonstrate the application of intelligent software as a fault detection, isolation, and recovery methodology for space power systems. This report discusses both the hardware and software elements used to construct the present configuration of the brassboard. The brassboard power components are described. These include the solid-state switches (herein referred to as switchgear), transformers, sources, and loads. Closely linked to this power portion of the brassboard is the first level of embedded control. Hardware used to implement this control and its associated software is discussed. An Ada software program, developed by Lewis Research Center's Space Station Freedom Directorate for their 20 kHz testbed, is used to control the brassboard's switchgear, as well as monitor key brassboard parameters through sensors located within these switches. The Ada code is downloaded from a PC/AT, and is resident within the 8086 microprocessor-based embedded controllers. The PC/AT is also used for smart terminal emulation, capable of controlling the switchgear as well as displaying data from them. Intelligent control is provided through use of a T1 Explorer and the Autonomous Power Expert (APEX) LISP software. Real-time load scheduling is implemented through use of a 'C' program-based scheduling engine. The methods of communication between these computers and the brassboard are explored. In order to evaluate the features of both the brassboard hardware and intelligent controlling software, fault circuits have been developed and integrated as part of the brassboard. A description of these fault circuits and their function is included. The brassboard has become an extremely useful test facility, promoting artificial intelligence (AI) applications for power distribution systems. system performance. &Modifications and enhancements to improve the brassboard's operation are discussed.

Merolla, Anthony

1992-10-01

328

Power line detection system  

DOEpatents

A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard. 4 figs.

Latorre, V.R.; Watwood, D.B.

1994-09-27

329

Coproduction of electric power and Fischer-Tropsch products (CATL-078)  

SciTech Connect

Because the coal gas produced from modern coal gasifiers can be purified to be compatable with slurry-phase F-T systems, it is feasible to integrate F-T synthesis with an IGCC facility to coproduce clean electric power and excellent quality nation fuels with high overall efficiency. This is similar in concept to coproducing electric power and methanol in a once-through process, and the feasibility of this concept has been extensively studied by EPRI. In the once-through methanol concept, the methanol could be used as peaking fuel in the power plant or sold as a chemical or fuel. This paper analyses this once-through F-T concept to determine the cost and efficiency advantages of a facility that coproduces power and transporation fuels compared to stand-alone IGCC and F-T facilities. The results of this analysis indicate that a coproduction facility can reduce the required selling price of transportation fuels by up to 15 percent compared to stand-alone facilities, and do so with no additional cost of electric power over the stand-alone IGCC case. This cost savings can also be achieved at a higher overall efficiency. Such a coproduction facility may allow coal-based IGCC technology to penetrate more rapidly into the marketplace. An independent power producer (IPP) may find this concept attractive since it allows the flexible production of power (for load following) and fuel as dictated by demand with no overall loss of plant capacity. In addition, the risk of plant investment is lowered by producing products for two markets.

Gray, D.; Tomlinson, G. [Mitre Corp., McLean, VA (United States)

1994-02-01

330

Precision Geocoding Demonstrator System.  

National Technical Information Service (NTIS)

An overview of a geocoding system designed as stand alone, which with a minimum of modifications can be adapted to interface with any SAR (Synthetic Aperture Radar) processor generating imagery in zero Doppler coordinates and being adequately annotated, i...

J. E. Laycock J. Whalley

1992-01-01

331

Power systems and power plant control  

SciTech Connect

This Proceedings consists of the 6 plenary papers and 65 of the contributed papers which were presented at the IFAC Symposium on Power Systems and Power Plant Control, held in Beijing, China on August 12-15, 1986. The control of power systems and of power plants is a subject of worldwide interest which continues to sustain a high level of research, development, and application activities in many diverse yet complementary areas. Papers pertaining to thirteen areas directly related to power system and power plant control are included in this Proceedings. The generation, transmission, and distribution of electrical energy for maximum economy, reliability, and quality of service, require both realtime control systems as well as offline support functions. The papers in this volume present state-of-the-art methods in hardware and software for both real-time control and offline decision-making. The functions and techniques described include linear and nonlinear optimization, static and dynamic state estimation, security analysis, generation control, excitation and voltage control, power plant modelling and control, stability analysis, emergency and restorative controls, large-scale sparse matrix techniques, data communications via wide area networks, microcomputer systems, power system stabilizers, load forecasting, optimum generation scheduling, and power system control centers.

Pingyang, W.

1987-01-01

332

Uninterruptible power system  

SciTech Connect

The present device is power system for providing an uninterruptible power supply to an external load comprising a flywheel generator, a first motor, a standby generator, and a transfer controller. The flywheel generator is adapted to supply energy to the external load. The first motor is drivingly connected to the flywheel generator. The first motor is adapted to be connected to a source of power external to the power system. The standby generator is electrically connected to the first motor. A standby motor is drivingly connected to the standby generator. The transfer controller is adapted to switchably interconnect the first motor to the source of power and to interconnect the standby generator to the first motor. The flywheel generator comprises a flywheel having a vertical axis, a shaft connected to the flywheel, and a synchronous A.C. generator arranged about the shaft. The standby motor is a diesel engine having an electric starter. A voltage regulator is electrically connected about the output of the flywheel generator.

Gottfried, C.F.

1984-07-17

333

Heatpipe power system development  

SciTech Connect

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of the project was to develop a design approach that could enable the development of near-term, low-cost, space fission-power systems. Sixteen desired attributes were identified for such systems and detailed analyses were performed to verify that they are feasible. Preliminary design work was performed on one concept, the Heatpipe Power system (HPS). As a direct result of this project, funding was obtained from the National Aeronautics and Space Administration to build and test an HPS module. The module tests went well, and they now have funding to build a bimodal module.

Houts, M.G.; Poston, D.I.

1998-12-31

334

Radiographic Comparison of Four Anterior Fusion Methods in Two Level Cervical Disc Diseases : Autograft Plate Fixation versus Cage Plate Fixation versus Stand-Alone Cage Fusion versus Corpectomy and Plate Fixation  

PubMed Central

Objective To evaluate radiographic results of anterior fusion methods in two-level cervical disc disease : tricortical autograft and plate fixation (ACDF-AP), cage and plate fixation (ACDF-CP), stand-alone cage (ACDF-CA), and corpectomy and plate fixation (ACCF). Methods The numbers of patients were 70 with a minimum 6 month follow-up (ACDF-AP : 12, ACDF-CP : 27, ACDF-CA : 15, and ACCF : 16). Dynamic simple X-ray and computed tomography were evaluated preoperatively, postoperatively, 6 month, and at the final follow-up. The fusion and subsidence rates at the final were determined, and global cervical lordosis (GCL), cervical range of motion, fused segment angle (FSA), and fused segment height (FSH) were analyzed. Results Nonunion was observed in 4 (25%) patients with ACDF-CA, 1 (8%) patient with ACDF-AP, 1 (4%) patient with ACDF-CP. The number of loss of FSH (%) more than 3 mm were 2 patients (16%) in ACDF-AP, 3 patients (11%) in ACDF-CP, 5 patients (33%) in ACDF-CA, and 3 patients (20%) in ACCF. The GCL was decreased with ACDF-CA and increased with others. The FSA was increased with ACDF-AP, ACDF-CP, and ACCF, but ACDF-CA was decreased. At the final follow-up, the FSH was slightly decreased in ACDF-CP, ACDF-AP, and ACCF, but ACDF-CA was more decreased. Graft related complication were minimal. Screw loosening, plate fracture, cage subsidence and migration were not identified. Conclusion ACDF-CP demonstrated a higher fusion rate and less minimal FSH loss than the other fusions in two-level cervical disc disease. The ACDF-AP and ACCF methods had a better outcome than the ACDF-CA with respect to GCL, FSA, and FSH.

Kim, Min-Ki; Jeon, Kwang-Mo; Kim, Tae-Sung

2012-01-01

335

Financial study of commercialization of solar central receiver power systems  

NASA Astrophysics Data System (ADS)

Commercialization requires that central receiver (CR) systems meet the economic criteria used by industry to select systems for capital ventures. Quantitative estimates are given of the investment required by government, utilities, and the manufacturing sector to meet the energy displacement goals for central receiver technology. Initial solar repowering and stand-alone electric utility plants will not have economic comparability with competitive energy sources. A major factor for this is that initial (first of a kind) heliostat costs will be high. As heliostat costs are reduced due to automated manufacturing economies, learning, and high volume production, central receiver technology will become more competitive. Under this task, several scenarios (0.1, 0.5, and 1.0 quad/y) were evaluated to determine the effect on commercial attractiveness and to determine the cost to government to bring about commercialization of solar central receivers.

1981-03-01

336

TOPEX electrical power system  

NASA Astrophysics Data System (ADS)

The TOPEX mission requirements which impact the power requirements and analyses are presented. A description of the electrical power system (EPS), including energy management and battery charging methods that were conceived and developed to meet the identified satellite requirements, is included. Analysis of the TOPEX EPS confirms that all of its electrical performance and reliability requirements have been met. The TOPEX EPS employs the flight-proven modular power system (MPS) which is part of the Multimission Modular Spacecraft and provides high reliability, abbreviated development effort and schedule, and low cost. An energy balance equation, unique to TOPEX, has been derived to confirm that the batteries will be completely recharged following each eclipse, under worst-case conditions. TOPEX uses three NASA Standard 50AH Ni-Cd batteries, each with 22 cells in series. The MPS contains battery charge control and protection based on measurements of battery currents, voltages, temperatures, and computed depth-of-discharge. In case of impending battery depletion, the MPS automatically implements load shedding.

Chetty, P. R. K.; Roufberg, Lew; Costogue, Ernest

337

Distributed Power System for Microsatellites.  

National Technical Information Service (NTIS)

The Aerospace Corporation has independently developed a distributed 'Ring Bus' electric power system for Picosatellites. This distributed power system architecture is being implemented on a number of upcoming Picosatellite missions. The first implementati...

E. J. Simburger D. Rumsey D. Hinkley S. Liu P. Carian

2004-01-01

338

Main Injector power distribution system  

SciTech Connect

The paper describes a new power distribution system for Fermilab's Main Injector. The system provides 13.8 kV power to Main Injector accelerator (accelerator and conventional loads) and is capable of providing power to the rest of the laboratory (backfeed system). Design criteria, and features including simulation results are given.

Cezary Jach and Daniel Wolff

2002-06-03

339

Limits to power system growth  

Microsoft Academic Search

In the design of space nuclear power systems a variety of conversion techniques may be used, each with its own advantages and disadvantages. A study was performed which analyzed over 120 proposed system designs. The designs were compared to identify the optimum conversion system as a function of power level and find limits to specific mass (kg\\/kWe) for each power

Stephen M. Slater; Andrew C. Klein; Brent J. Webb; Keith A. Pauley

1993-01-01

340

POWER SYSTEMS DEVELOPMENT FACILITY  

SciTech Connect

This report discusses test campaign GCT4 of the Kellogg Brown & Root, Inc. (KBR) transport reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The transport reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using one of two possible particulate control devices (PCDs). The transport reactor was operated as a pressurized gasifier during GCT4. GCT4 was planned as a 250-hour test run to continue characterization of the transport reactor using a blend of several Powder River Basin (PRB) coals and Bucyrus limestone from Ohio. The primary test objectives were: Operational Stability--Characterize reactor loop and PCD operations with short-term tests by varying coal-feed rate, air/coal ratio, riser velocity, solids-circulation rate, system pressure, and air distribution. Secondary objectives included the following: Reactor Operations--Study the devolatilization and tar cracking effects from transient conditions during transition from start-up burner to coal. Evaluate the effect of process operations on heat release, heat transfer, and accelerated fuel particle heat-up rates. Study the effect of changes in reactor conditions on transient temperature profiles, pressure balance, and product gas composition. Effects of Reactor Conditions on Synthesis Gas Composition--Evaluate the effect of air distribution, steam/coal ratio, solids-circulation rate, and reactor temperature on CO/CO{sub 2} ratio, synthesis gas Lower Heating Value (LHV), carbon conversion, and cold and hot gas efficiencies. Research Triangle Institute (RTI) Direct Sulfur Recovery Process (DSRP) Testing--Provide syngas in support of the DSRP commissioning. Loop Seal Operations--Optimize loop seal operations and investigate increases to previously achieved maximum solids-circulation rate.

Unknown

2002-11-01

341

48 CFR 252.242-7004 - Material management and accounting system.  

Code of Federal Regulations, 2010 CFR

... ) means the Contractor's system or systems for planning, controlling, and accounting...material. Material management and accounting systems may be manual or automated. They may be stand-alone systems or they may be integrated with...

2009-10-01

342

48 CFR 252.242-7004 - Material management and accounting system.  

Code of Federal Regulations, 2010 CFR

... ) means the Contractor's system or systems for planning, controlling, and accounting...material. Material management and accounting systems may be manual or automated. They may be stand-alone systems or they may be integrated with...

2010-10-01

343

Manned spacecraft electrical power systems  

Microsoft Academic Search

A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward growth of electrical power requirements and operational lifetimes with each succeeding space program. A review of the design philosophy and development experience associated with the Space Shuttle Orbiter electrical power system is presented, beginning with the state of technology

W. E. Simon; D. L. Nored

1987-01-01

344

BK070031, IDM Symphony System 2.0  

Center for Biologics Evaluation and Research (CBER)

Text Version... The system can be stand-alone or interface with other systems to allow for two-way communication of donor and donation information. ... More results from www.fda.gov/downloads/biologicsbloodvaccines/bloodbloodproducts

345

Solar Thermal Electric Power Systems.  

National Technical Information Service (NTIS)

The objective of this research program is to develop design parameters for solar thermal electric power systems that can provide lowest cost electric power. Parametric performance and cost models are being developed for subsystems such as the concentrator...

1974-01-01

346

Modular airborne remote sampling and sensing system (MARSSS)  

SciTech Connect

Sandia is developing a modular airborne instrumentation system for the Environmental Protection Agency. This system will allow flexibility in the choice of instruments by standardizing mountings, power supplies and sampling modes. The objective is to make it possible to perform aerial surveys from chartered aircraft that have not been adapted in a more than superficial manner. It will also allow the experimenter to tailor his choice of instruments to the specific problem. Since the equipment will have a stand-alone capability, it can be applied to other problems such as long-term unattended use at remote locations or in toxic or otherwise hazardous environments.

Woods, R.O.

1982-04-01

347

Plural engine power producing system  

SciTech Connect

A system is described for producing power utilizing gas turbine engines comprising: a primary engine including a gas generator and a power turbine; a secondary engine including: a compressor; a combustor; and a turbine driving engaged with the compressor; drive means selectively coupling the gas generator of the primary engine and the secondary engine for augmenting the output power of the primary engine and for achieving improved fuel consumption of the system at low power levels.

Banthin, C.; Deman, J.

1993-08-31

348

Evaluation of the Tri-Service Radiology System at the Naval Hospital, Bethesda.  

National Technical Information Service (NTIS)

The Tri-Service Medical Information Systems (TRIMIS) Program Office (TPO) has installed four initial stand-alone computer systems for support of radiology operations in Medical Treatment Facilities (MTFs). The system, known as the Tri-Service Radiology Sy...

1983-01-01

349

Control of electric power systems  

Microsoft Academic Search

The increase in size and complexity of interconnected electric power systems, coupled with the industrial commitment to maximize security at a minimum cost, has led to the development of many special control devices. These control devices ensure that the electric power system is able to operate, without instability, under a wide range of system conditions. This article presents a tutorial

Magdi S. Mahmoud; ABdulla Ismail

2003-01-01

350

Higher voltage aircraft power systems  

Microsoft Academic Search

Modern aircraft designs are focused on minimising the use of engine bleed air, eliminating gearboxes, and reducing the reliance on hydraulic systems. Instead, many of these mechanical systems will be replaced with electrical versions. The increasing amounts of electrical power that will be shipped through an aircraft means that it is increasingly difficult to rely on low voltage power systems

Ian Cotton; Andrew Nelms

2008-01-01

351

Thermoelectric module construction for low temperature gradient power generation  

Microsoft Academic Search

Energy related carbon dioxide emissions are the largest contributors to greenhouse gasses [1]. Thermoelectric power generation that exploits natural temperature differences between the air and earth can be a zero-emission replacement to small stand-alone power sources. Maximizing the temperature drop across the module is crucial to achieving optimal output power. An equation relating output power to thermoelectric module parameters is

Y. Meydbray; R. Singh; Ali Shakouri

2005-01-01

352

US electric power system reliability  

NASA Astrophysics Data System (ADS)

Electric energy supply, transmission and distribution systems are investigated in order to determine priorities for legislation. The status and the outlook for electric power reliability are discussed.

353

Development of high-performance solar LED lighting system  

Microsoft Academic Search

The present study developed a high-performance charge\\/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven

B. J. Huang; M. S. Wu; P. C. Hsu; J. W. Chen; K. Y. Chen

2010-01-01

354

Power quality load management for large spacecraft electrical power systems  

NASA Astrophysics Data System (ADS)

In December, 1986, a Center Director's Discretionary Fund (CDDF) proposal was granted to study power system control techniques in large space electrical power systems. Presented are the accomplishments in the area of power system control by power quality load management. In addition, information concerning the distortion problems in a 20 kHz ac power system is presented.

Lollar, Louis F.

1988-09-01

355

Hydrogen Powered Car Control System  

Microsoft Academic Search

Mobile embedded systems belong among the typical applications of the distributed systems control in real time. An example of a mobile control system is the hydrogen powered prototype car control system. The proposal and realization of such distributed control system represents a demanding and complex task of real time control for track optimizing with minimal fuel consumption. Design and realization

Srovnal Vilem; Koziorek Jiri; Horak Bohumil; Adam George; Garani Georgia

2008-01-01

356

Remote powered data transmission system  

Microsoft Academic Search

The authors consider remote powered data transmission system issues. In the systems under consideration, two stations, one at the beginning and one at the end, provide energy and regenerate the signal; several peripheral stations are serially powered along the line. Particular attention is given to energy problems, cable and operator safety, and noise generation. The objective is to ensure a

A. Fausti; R. Lelli; G. Mesini

1989-01-01

357

Antares power amplifier optical system  

Microsoft Academic Search

The optical systems of the six Antares laser power amplifiers are described. These assemblies are preceded by the front end optics and followed by the target system. Each power amplifier receives an annular input beam and divides it into 12 beams which are then directed to double pass them through 12 gain regions surrounding a central electron gun. Provisions are

C. J. Silvernail; K. C. Jones

1979-01-01

358

Operational performance of the photovoltaic-powered grain mill and water pump at Tangaye, Upper Volta  

NASA Astrophysics Data System (ADS)

The first two years of operation of a stand alone photovoltaic (PV) power system for the village of Tangaye, Upper Volta in West Africa are described. The purpose of the experiment was to demonstrate that PV systems could provide reliable electrical power for multiple use applications in remote areas where local technical expertise is limited. The 1.8 kW (peak) power system supplies 120-V (d.c.) electrical power to operate a grain mill, a water pump, and mill building lights for the village. The system was initially sized to pump a part of the village water requirements from an existing improved well, and to meet a portion of the village grain grinding requirements. The data, observations, experiences, and conclusions developed during the first two years of operation are discussed. Reports of tests of the mills used in the project are included.

Martz, J. E.; Ratajczak, A. F.; Delombard, R.

1982-02-01

359

Scaling of advanced power systems  

NASA Astrophysics Data System (ADS)

Parts of a study conducted to examine state-of-the-art power systems applicable to future military spacecraft are summarized. The study focused on burst-mode megawatt-class CW power, such as might be applied to SDIO directed energy systems, but lower-power, continuous-duty subsystems were included in less detail. A set of simple mass and volume algorithms has been developed to approximate several prime systems, and these were incorporated into a Lotus 1-2-3 spreadsheet. Among the power subsystems included in that study were primary batteries, alkaline primary fuel cells, and combustion turbogenerators. These systems, which are the most likely candidates for mobile battlefield power, are described in this paper.

Wiley, Robert L.

1991-12-01

360

Optimizal design and control strategies for novel Combined Heat and Power (CHP) fuel cell systems. Part II of II, case study results.  

SciTech Connect

Innovative energy system optimization models are deployed to evaluate novel fuel cell system (FCS) operating strategies, not typically pursued by commercial industry. Most FCS today are installed according to a 'business-as-usual' approach: (1) stand-alone (unconnected to district heating networks and low-voltage electricity distribution lines), (2) not load following (not producing output equivalent to the instantaneous electrical or thermal demand of surrounding buildings), (3) employing a fairly fixed heat-to-power ratio (producing heat and electricity in a relatively constant ratio to each other), and (4) producing only electricity and no recoverable heat. By contrast, models discussed here consider novel approaches as well. Novel approaches include (1) networking (connecting FCSs to electrical and/or thermal networks), (2) load following (having FCSs produce only the instantaneous electricity or heat demanded by surrounding buildings), (3) employing a variable heat-to-power ratio (such that FCS can vary the ratio of heat and electricity they produce), (4) co-generation (combining the production of electricity and recoverable heat), (5) permutations of these together, and (6) permutations of these combined with more 'business-as-usual' approaches.

Colella, Whitney G.

2010-04-01

361

Optimal design and control strategies for novel combined heat and power (CHP) fuel cell systems. Part II of II, case study results.  

SciTech Connect

Innovative energy system optimization models are deployed to evaluate novel fuel cell system (FCS) operating strategies, not typically pursued by commercial industry. Most FCS today are installed according to a 'business-as-usual' approach: (1) stand-alone (unconnected to district heating networks and low-voltage electricity distribution lines), (2) not load following (not producing output equivalent to the instantaneous electrical or thermal demand of surrounding buildings), (3) employing a fairly fixed heat-to-power ratio (producing heat and electricity in a relatively constant ratio to each other), and (4) producing only electricity and no recoverable heat. By contrast, models discussed here consider novel approaches as well. Novel approaches include (1) networking (connecting FCSs to electrical and/or thermal networks), (2) load following (having FCSs produce only the instantaneous electricity or heat demanded by surrounding buildings), (3) employing a variable heat-to-power ratio (such that FCS can vary the ratio of heat and electricity they produce), (4) co-generation (combining the production of electricity and recoverable heat), (5) permutations of these together, and (6) permutations of these combined with more 'business-as-usual' approaches. The detailed assumptions and methods behind these models are described in Part I of this article pair.

Colella, Whitney G.

2010-06-01

362

Prediction on future DC power system  

Microsoft Academic Search

Analyzed some serious issues, including power energy quality and large area power interruption, require complex method to overcome in 3-phase power system, so, suggested to go other way, proposed independent full DC power system to become one of main power systems in the future. The authors emphasized the necessity and capability of full DC power systems in the significance of

Qianzhi Zhou; Defang Yuan

2009-01-01

363

Ignitor Electrical Power Supply System  

Microsoft Academic Search

An iterative optimization process to reduce the total installed electrical power required for Ignitor has been performed, bringing its value down to about 70% of that estimated originally. Ignitor is planned to be installed within the 400 kV Station of Rondissone (near Turin). The required electrical power (1000 MVA \\/ 320 MVAr, including 480 MVAr locally compensated through static system,

Alberto Coletti; Roberto Coletti; Pietro Costa; Giuseppe Maffia; Giuseppe Ramogida; Massimo Roccella; Maurizio Santinelli; Fabio Starace

2004-01-01

364

XML-Based Knowledge Management System of Port Information for U.S. Coast Guard Cutters.  

National Technical Information Service (NTIS)

This thesis describes the development of a prototype application that collects, manages, and distributes knowledge gained by Coast Guard cutter crews making port calls throughout the world. The system uses XML technologies in server/client and stand alone...

J. D. Stewart

2003-01-01

365

Energy Conservation in the Electric Power System.  

National Technical Information Service (NTIS)

The possibilities for energy conservation in the Norwegian electric power supply system are analysed. This power system is based exclusively on hydroelectric power and consists of water storage reservoirs, pipes and tunnels for water transport, power plan...

A. Killingtveit K. Tvinnereim

1983-01-01

366

Optimalisatie en ontwerp van een pv/accu-systeem met back-upgenerator. (Optimization and design of a photovoltaic/accumulator system with aback-up generator).  

National Technical Information Service (NTIS)

Four different options for stand-alone energy supply systems havebeen compared to find out under which conditions application of aphotovoltaic battery system with back-up generator is economicallyfeasible. The options are: petrol generator; petrol generat...

V. A. P. Van Dijk E. A. Alsema

1989-01-01

367

Integrated protection on shipboard integrated power system  

Microsoft Academic Search

This paper had researched the protection issues for the shipboard integrated power system. Comparing with traditional ship power system, ship integrated power system is a electrical system wide platform entirely which needs to supply much higher density power to the all electrical ship. In this paper, the idea of integrated backup protection in the terrestrial power system was referred and

HanYu Liu; LongHua Mu

2011-01-01

368

Clean coal power system  

SciTech Connect

A coal burning power plant which produces electricity at high efficiency and with very low levels of atmospheric contamination. A fluidized bed of limestone and coal is used to burn the coal with little air pollution, and a large quantity of specially constructed heat pipes transfer the heat to a closed cycle gas turbine with very low temperature loss. The preferred embodiments of the heat pipes are constructed with steel casing, have a thin aluminum oxide layer on their surfaces to prevent hydrogen permeation into the casing and have a plasma sprayed coating of ceramic on the portion within the fluidized bed to prevent erosion of the heat pipe casing by the solid particles within the bed.

Eastman, G.Y.

1983-04-19

369

The ac power system testbed  

NASA Astrophysics Data System (ADS)

The object of this program was to design, build, test, and deliver a high frequency (20 kHz) Power System Testbed which would electrically approximate a single, separable power channel of an IOC Space Station. That program is described, including the technical background, and the results are discussed showing that the major assumptions about the characteristics of this class of hardware (size, mass, efficiency, control, etc.) were substantially correct. This testbed equipment was completed and delivered and is being operated as part of the Space Station Power System Test Facility.

Mildice, J.; Sundberg, R.

1987-11-01

370

Manned spacecraft electrical power systems  

SciTech Connect

A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward growth of electrical power requirements and operational lifetimes with each succeeding space program. A review of the design philosophy and development experience associated with the Space Shuttle Orbiter electrical power system is presented, beginning with the state of technology at the conclusion of the Apollo Program. A discussion of prototype, verification, and qualification hardware is included, and several design improvements following the first Orbiter flight are described. The problems encountered, the scientific and engineering approaches used to meet the technological challenges, and the results obtained are stressed. Major technology barriers and their solutions are discussed, and a brief Orbiter flight experience summary of early Space Shuttle missions is included. A description of projected Space Station power requirements and candidate system concepts which could satisfy these anticipated needs is presented.

Simon, W.E.; Nored, D.L.

1987-03-01

371

Protection of industrial power systems  

SciTech Connect

The protection which is installed on an industrial power system is likely to be subjected to more difficult conditions than the protection on any other kind of power system. This book is intended to help achieve an understanding of the protection necessary and covers the whole area of industrial power system protection, starting with the many simple devices which are employed. Covers vital aspects such as the modern cartridge fuse, types of relays, and the role of the current transformer. Includes critical examination of the widely used inverse definite-minimum time overcurrent relay, the theory of the Merz-Price protection system and the development of the high-impedance relay system. Describes commissioning and maintenance testing of equipment.

Davies, T.

1983-01-01

372

Dynamic Isotope Surface Power Systems  

NASA Astrophysics Data System (ADS)

The Dynamic Isotope Power Systems (DIPS) demonstration program, sponsored by the U.S. Department of Energy (DOE) with support funding from the National Aeronautics and Space Administration (NASA), is currently focused on the development of a standardized 2.5 kWe portable generator for multiple applications on the lunar or Martian surface. A variety of potential remote and mobile applications has been identified by NASA including surface rovers for both short and extended duration missions, remote power to science packages, and backup to central base power. Recent work focused on refining the 2.5 kWe design including assessing compatibility with the Martian environment to assure the design is suitable while imposing only a minor mass penalty on lunar operations. Additional work included a study performed to compare the DIPS with regenerative fuel cell systems for lunar mobile and remote power systems. Power requirements were reviewed and a modular system chosen for the comparison. Finally, a plan and cycle schematic were generated for an early demonstration of a prototypic isotope power Brayton system using the Antarctic as the test bed.

Hunt, Maribeth E.; Rovang, Richard D.; Cataldo, Robert

1991-09-01

373

Power Systems Development Facility, PFBC system perspectives.  

National Technical Information Service (NTIS)

Southern Company Services (SCS) has investigated the feasibility of constructing a Power Systems Development Facility (PSDF) at the Southem Company's Clean Coal Research Center in Wilsonville, Alabama. The PSDF combines a number of pilot-scale test facili...

G. H. Griswold T. J. Boyd M. O. Fankhanel C. J. Crumm D. H. Pontius

1993-01-01

374

Solar power source for a lighting system  

Microsoft Academic Search

A solar recharged power supply circuit for a lighting system which circuit includes a rechargeable power source, a solar powered recharger connected to that rechargeable power source and which circuit prevents discharge of that rechargeable power source through the solar powered recharger during times when the recharger is inactive; prevents overcharging of that power source; prevents discharging that power source

1982-01-01

375

Power Systems Advanced Research  

SciTech Connect

In the 17 quarters of the project, we have accomplished the following milestones - first, construction of the three multiwavelength laser scattering machines for different light scattering study purposes; second, build up of simulation software package for simulation of field and laboratory particulates matters data; third, carried out field online test on exhaust from combustion engines with our laser scatter system. This report gives a summary of the results and achievements during the project's 16 quarters period. During the 16 quarters of this project, we constructed three multiwavelength scattering instruments for PM2.5 particulates. We build up a simulation software package that could automate the simulation of light scattering for different combinations of particulate matters. At the field test site with our partner, Alturdyne, Inc., we collected light scattering data for a small gas turbine engine. We also included the experimental data feedback function to the simulation software to match simulation with real field data. The PM scattering instruments developed in this project involve the development of some core hardware technologies, including fast gated CCD system, accurately triggered Passively Q-Switched diode pumped lasers, and multiwavelength beam combination system. To calibrate the scattering results for liquid samples, we also developed the calibration system which includes liquid PM generator and size sorting instrument, i.e. MOUDI. In this report, we give the concise summary report on each of these subsystems development results.

California Institute of Technology

2007-03-31

376

Powerful Midwest Storm System  

NASA Video Gallery

This animation of imagery from NOAA’s GOES-13 satellite shows the movement of storm systems in the south central United States on May 20, 2013. Warm, moist gulf air flowing across Texas, Oklahoma, Kansas and Missouri triggered tornadoes, with an F-4 tornado (winds between 166 and 200 mph) crossing Moore, Okla., on May 20 around 3 p.m. CDT. Credit: NASA/NOAA GOES Project, Dennis Chesters › Related story › Download video

Robert Garner

2013-05-21

377

Artificial Representation of Power Systems  

Microsoft Academic Search

The size and complexity of present-day power systems have increased to the point where the prediction of the behavior of the system by analytical methods is more and more difficult. The solution of commercial networks by Kirchhoff's Laws or by cut and try methods, even with the help of star-delta transformations, leads to such involved equations that the need for

H. H. Spencer; H. L. Hazen

1925-01-01

378

Probabilistic assessment of power systems  

Microsoft Academic Search

Reliability is an important issue in power systems and historically has been assessed using deterministic criteria and indexes. However, these approaches can be, and in many cases have been, replaced by probabilistic methods that are able to respond to the actual stochastic factors that influence the reliability of the system. In the days of global, completely integrated and\\/or nationalized electricity

RON ALLAN; ROY BILLINTON

2000-01-01

379

Solar power source for a lighting system  

SciTech Connect

A solar recharged power supply circuit for a lighting system which circuit includes a rechargeable power source, a solar powered recharger connected to that rechargeable power source and which circuit prevents discharge of that rechargeable power source through the solar powered recharger during times when the recharger is inactive; prevents overcharging of that power source; prevents discharging that power source below a predetermined level; and automatically connects and disconnects the lighting system to and from the rechargeable power source.

Rogers, W.E.

1982-02-02

380

Power systems for space exploration  

SciTech Connect

The Outreach Program was designed to solicit creative ideas from academia, research institutions, private enterprises, and the general public and is intended to be helpful in defining promising technical areas and program paths for more detailed study. To the Outreach Program, a number of power system concepts were proposed. In conclusion, there are a number of advanced concepts for space power and propulsion sources that deserve study if we want to expand our ability to not only explore space, but to utilize it. Advanced nuclear concepts and power beaming concepts are two areas worthy of detailed assessments.

Shipbaugh, C.; Solomon, K.A.

1992-01-01

381

The Information System For Power Distribution System As Answer On New Demands In Power Distribution System  

Microsoft Academic Search

Information is most important thing now in 21st century. The many power utility company do not use information system for technical problems. This company work as before ten or fifty years. Only way for progress is insert information system into power utility system. Information system go into power utility company first as billing system. Next step is accounting, information system

S. M. Dragojlovic; O. T. Milenkovic; M. Vujicic

2005-01-01

382

Integration of the Premium Power Supply on Electric Power System  

Microsoft Academic Search

This paper describes an inverter-interfaced distributed generation (DG) system that is interconnected with the electric power system (EPS). This system has two main goals such as to serve the customer with reliable electric power and to improve power quality like harmonics and voltage event. This system is interfaced through the series and the shunt inverters because inverters are effective to

Jin-Woo Park; Il-Yop Chung; Kyoung-Nam Kim; Jong-Hun Lee; Seung-Il Moon; Byung-Moon Han

2005-01-01

383

Efficiency and internal power flow of renewable power supply system  

Microsoft Academic Search

Supplying of separate isolated load systems such as street lighting can be realized by combination of wind and solar power. Hybrid power supply system consists of a number of independent and different sources of electrical energy with different operating times during different seasons and with energy storage system. Deployment of a hybrid power system is expected in places outside the

Petr Bilik; Jakub Kvapil; Stanislav Misak

2011-01-01

384

Models for multimegawatt space power systems  

NASA Astrophysics Data System (ADS)

This report describes models for multimegawatt, space power systems which Sandia's Advanced Power Systems Division has constructed to help evaluate space power systems for SDI's Space Power Office. Five system models and models for associated components are presented for both open (power system waste products are exhausted into space) and closed (no waste products) systems: open, burst mode, hydrogen cooled nuclear reactor - turboalternator system; open, hydrogen-oxygen combustion turboalternator system; closed, nuclear reactor powered Brayton cycle system; closed, liquid metal Rankine cycle system; and closed, in-core, reactor thermionic system. The models estimate performance and mass for the components in each of these systems.

Edenburn, M. W.

1990-06-01

385

Models for multimegawatt space power systems  

SciTech Connect

This report describes models for multimegawatt, space power systems which Sandia's Advanced Power Systems Division has constructed to help evaluate space power systems for SDI's Space Power Office. Five system models and models for associated components are presented for both open (power system waste products are exhausted into space) and closed (no waste products) systems: open, burst mode, hydrogen cooled nuclear reactor -- turboalternator system; open, hydrogen-oxygen combustion turboalternator system; closed, nuclear reactor powered Brayton cycle system; closed, liquid metal Rankine cycle system; and closed, in-core, reactor therminonic system. The models estimate performance and mass for the components in each of these systems. 17 refs., 8 figs., 15 tabs.

Edenburn, M.W.

1990-06-01

386

MCFC power plant system verification  

SciTech Connect

In pursuit of commercialization, efforts are underway to: (1) advance the technology base by enhancing performance and demonstrating endurance, (2) scale up stack to the full area and height, (3) acquire stack manufacturing capability and experience, (4) establish capability as well as gain experience for power plant system testing of the full-height carbonate fuel cell stack, (5) and define power plant design and develop critical subsystem components. All the major project objectives have already been attained. Over the last year, significant progress has been achieved in establishing the full-height stack design, gaining stack manufacturing and system integrated testing experience, and verifying the major equipment design in power plant system tests. In this paper, recent progresses on stack scaleup, demonstration testing, BOP verification, and stack endurance are presented.

Farooque, M.; Bernard, R.; Doyon, J.; Paetsch, L.; Patel, P.; Skok, A.; Yuh, C.

1993-11-01

387

An expert system for power systems maintenance  

Microsoft Academic Search

When power equipment fails, maintenance personnel have traditionally had to investigate and repair the equipment by using information supplied by supervision and control systems, specified in manuals, or gained through personal experience. To enable maintenance personnel to respond more quickly and accurately, the authors have developed an expert system (called ALICE-ES), that provides diagnostic expert know-how and emergency procedures arranged

A. Mitsuhashi; T. Maruyama; H. Inoue; T. Takeda

1993-01-01

388

ADVANCED POWER SYSTEMS ASH BEHAVIOR IN POWER SYSTEMS  

SciTech Connect

The overall goal of this initiative is to develop fundamental knowledge of ash behavior in power systems for the purpose of increasing power production efficiency, reducing operation and maintenance costs, and reducing greenhouse gas emissions into the atmosphere. The specific objectives of this initiative focus primarily on ash behavior related to advanced power systems and include the following: ? Determine the current status of the fundamental ash interactions and deposition formation mechanisms as already reported through previous or ongoing projects at the EERC or in the literature. ? Determine sintering mechanisms for temperatures and particle compositions that are less well known and remain for the most part undetermined. ? Identify the relationship between the temperature of critical viscosity (Tcv ) as measured in a viscometer and the crystallization occurring in the melt. ? Perform a literature search on the use of heated-stage microscopy (HSM) for examining in situ ash-sintering phenomena and then validate the use of HSM in the determination of viscosity in spherical ash particles. ? Ascertain the formation and stability of specific mineral or amorphous phases in deposits typical of advanced power systems. ? Evaluate corrosion for alloys being used in supercritical combustion systems.

CHRISTOPHER J. ZYGARLICKE; DONALD P. MCCOLLOR; JOHN P. KAY; MICHAEL L. SWANSON

1998-09-01

389

Intelligent network reconfiguration of shipboard power systems  

Microsoft Academic Search

Electric power systems of ships supply energy to sophisticated systems for weapons, communications, navigation and operation. In this new era of the US navy with goals to reduce manning and increase system survivability, automatic reconfiguration of the electrical network in a shipboard power system is critical for quickly restoring service to a section of the power of the power system

K. L. Butler-Purry; N. D. R. Sarma

2003-01-01

390

Dynamic power management of electronic systems  

Microsoft Academic Search

Dynamic power management is a design methodology aiming at contro lling perfor- mance and power levels of digital circuits and systems, with thegoal of extending the autonomous operation time of battery-powered systems, providing graceful perfor- mance degradation when supply energy is limited, and adapting power dissipation to satisfy environmental constraints. We survey system-level dynamic power m anagement techniques. We first

Luca Benini; Alessandro Bogliolo; Giovanni De Micheli

1998-01-01

391

High average power solid state laser power conditioning system  

SciTech Connect

The power conditioning system for the High Average Power Laser program at Lawrence Livermore National Laboratory (LLNL) is described. The system has been operational for two years. It is high voltage, high power, fault protected, and solid state. The power conditioning system drives flashlamps that pump solid state lasers. Flashlamps are driven by silicon control rectifier (SCR) switched, resonant charged, (LC) discharge pulse forming networks (PFNs). The system uses fiber optics for control and diagnostics. Energy and thermal diagnostics are monitored by computers.

Steinkraus, R.F.

1987-03-03

392

TPX power systems design overview  

SciTech Connect

The power systems for the Tokamak Physics Experiment (TPX) supply the Toroidal Field (TF). Poloidal Field (PF), Field Error Correction (FEC), and Fast Vertical Position Control (FVPC) coil systems, the Neutral Beam (NB), Ion Cyclotron (IC), Lower Hybrid (LH) and Electron Cyclotron (EC) heating and current drive systems, and all balance of plant loads. Existing equipment from the Tokamak Fusion Test Reactor (TFTR), including the motor-generator (MG) sets and the rectifiers, can be adapted for the supply of the TPX PF systems. A new TF power supply is required. A new substation is required for the heating and current drive systems (NB, IC, LH, and EC). The baseline TPX load can be taken directly from the grid without special provision, whereas if all upgrade options are undertaken, a modest amount of reactive compensation will be required. This paper describes the conceptual design of the power systems, with emphasis on the AC, TF, and PF Systems, and the quench protection of the superconducting coils.

Neumeyer, C. [Ebasco Services, Inc., New York, NY (United States); Bronner, G.; Lu, E.; Ramakrishnan, S. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Jackson, M. [Lawrence Livermore National Lab., CA (United States)

1993-11-01

393

Integrated solar power systems [space power applications  

Microsoft Academic Search

The authors are developing lightweight devices that are capable of solar energy conversion and storage. These integrated power supplies (IPS) incorporate photovoltaic power generation with thin-film lithium ion energy storage. Lithium ion devices with large energy densities and long cycling lifetimes are ideal for this application. The techniques used to fabricate the solar cell and battery component films are compatible

R. P. Raffaelle; J. Underwood; D. Scheiman; J. Cowen; P. Jenkins; A. F. Hepp; J. Harris; D. M. Wilt

2000-01-01

394

Options for Affordable Fission Surface Power Systems.  

National Technical Information Service (NTIS)

Fission surface power systems could provide abundant power anywhere on free surface of the moon or Mars. Locations could include permanently shaded regions on the moon and high latitudes on Mars. To be fully utilized; however, fission surface power system...

M. Houts S. Gaddis R. Porter M. VanDyke T. Godfroy S. Bragg-Sitton A. Garber B. Pearson

2006-01-01

395

A contactless power supply for photovoltaic power generation system  

Microsoft Academic Search

Among the alternative energy sources, the solar energy is recognized as an important energy source and its application is increasing. Especially in future, the hybrid solar energy generation system with battery and fuel cell will be widely used as an independent distributed power generation system. In this paper, a solar power hybrid home generation system using a contactless power supply

Eun-Soo Kim; Sung-In Kang; Kwang-Ho Yoon; Yoon-Ho Kim

2008-01-01

396

Analysis methods for wind turbine control and electrical system dynamics  

NASA Astrophysics Data System (ADS)

The integration of new energy technologies into electric power systems requires methods which recognize the full range of dynamic events in both the new generating unit and the power system. Since new energy technologies are initially perceived as small contributors to large systems, little attention is generally paid to system integration, i.e. dynamic events in the power system are ignored. As a result, most new energy sources are only capable of base-load operation, i.e. they have no load following or cycling capability. Wind turbines are no exception. Greater awareness of this implicit (and often unnecessary) limitation is needed. Analysis methods are recommended which include very low penetration (infinite bus) as well as very high penetration (stand-alone) scenarios.

Hinrichsen, E. N.

1995-05-01

397

Power systems for space exploration  

Microsoft Academic Search

The Outreach Program was designed to solicit creative ideas from academia, research institutions, private enterprises, and the general public and is intended to be helpful in defining promising technical areas and program paths for more detailed study. To the Outreach Program, a number of power system concepts were proposed. In conclusion, there are a number of advanced concepts for space

Calvin Shipbaugh; Kenneth A. Solomon

1992-01-01

398

Power system dynamic response calculations  

Microsoft Academic Search

Engineers in the power industry, face the problem that, while stability is increasingly a limiting factor in secure system operation, the simulation of system dynamic response is grossly overburdening on present-day digital computing resources. Each individual response case involves the step-by-step numerical solution in the time domain of perhaps thousands of nonlinear differential-algebraic equations, at a cost of up to

B. Stott

1979-01-01

399

Solar-powered lighting system  

SciTech Connect

A solar-powered lighting system suitable for signs or hoardings, navigation beacons or as an emergency supply for hotels, cinemas, hospitals or other services. The system incorporates solar cell arrays which generate electricity which is stored in batteries. A sensing circuit selectively connects the batteries to lights. A timing/switching circuit may be provided to selectively connect the lights to a mains supply.

O'Brien, P.

1984-11-20

400

Low Voltage Bulk Power System Restoration Simulation  

Microsoft Academic Search

Time is the crucial element in restorative state control for electric power systems. One method for reenergizing large portions of a blacked out electric power system with a minimum of switching and thus time to restoration, is described. Results of a simulated system restart utilizing actual power system facilities are compared to power flow studies. The simulation tests were performed

Edward Simburger; Francis Hubert

1981-01-01

401

Optimal power flows of interconnected power systems  

Microsoft Academic Search

The work presented in this paper seeks to provide a theoretically sound, yet practical foundation for the implementation of inter-utilities power exchanges based on spot pricing. The proposed approach allows the operational independence of each utility. Using decomposition-coordination techniques, a multi-area optimal power flow problem is reformulated as a master problem and a set of area-OPF subproblems, each associated with

J. A. Aguado; Victor H. Quintana; Antonio J. Conejo

1999-01-01

402

Power system applications for PASC converter systems  

SciTech Connect

This paper shows, using computer EMTP simulations, some preliminary results of applying pulse amplitude synthesis and control (PASC) technology to single-source level voltage converter system. The method can be applied to any single terminal pair source with appropriate modifications in power extraction interface and computer control program to match source and load impedance characteristics. The PASC realization as discussed here employs banks of transformers, one bank per phase, in which the primaries are connected in parallel through a switch matrix to the dc source. Two opposite polarity primaries per transformer are pulsed alternatively in time to produce an oscillatory sinusoidal output waveform. PASC conversion system capabilities to produce both leading and lagging power factor power output in single-phase and three-phase {Delta} or Y configurations are illustrated. EMTP simulations are used to demonstrate the converter capabilities. Also included are discussions regarding harmonics and potential control strategies to adapt the converter to an application or to minimize harmonics.

Donnelly, M.K. [Pacific Northwest Lab., Richland, WA (United States); Johnson, R.M. [Montana State Univ., Bozeman, MT (United States)

1994-04-01

403

Power system applications for PASC converter systems  

SciTech Connect

This paper shows, using computer EMTP simulations, some preliminary results of applying pulse amplitude synthesis and control (PASC) technology to single-source voltage converter systems. The method can be applied to any single terminal pair source with appropriate modifications in power extraction interface and computer control program to match source and load impedance characteristics. The PASC realization as discussed here employs banks of transformers, one bank per phase, in which the primary are connected in parallel through a switch matrix to the dc source. Two opposite polarity primaries per transformer are pulsed alternatively in time to produce an oscillatory sinusoidal output waveform. PASC conversion system capabilities to produce both leading and lagging power factor power output in single-phase and three-phase {Delta} or Y configurations are illustrated. EHTP simulations are used to demonstrate the converter capabilities. Also included are discussions regarding harmonics and potential control strategies to adapt the converter to an application or to minimize harmonics.

Donnelly, M.K. [Pacific Northwest Lab., Richland, WA (United States); Johnson, R.M. [Montana State Univ., Bozeman, MT (United States)

1995-01-01

404

Power system applications for PASC converter systems  

NASA Astrophysics Data System (ADS)

This paper shows, using computer EMTP simulations, some preliminary results of applying pulse amplitude synthesis and control (PASC) technology to single-source level voltage converter system. The method can be applied to any single terminal pair source with appropriate modifications in power extraction interface and computer control program to match source and load impedance characteristics. The PASC realization as discussed here employs banks of transformers, one bank per phase, in which the primaries are connected in parallel through a switch matrix to the dc source. Two opposite polarity primaries per transformer are pulsed alternatively in time to produce an oscillatory sinusoidal output waveform. PASC conversion system capabilities to produce both leading and lagging power factor power output in single-phase and three-phase (Delta) or Y configurations are illustrated. EMTP simulations are used to demonstrate the converter capabilities. Also included are discussions regarding harmonics and potential control strategies to adapt the converter to an application or to minimize harmonics.

Donnelly, M. K.; Johnson, R. M.

1994-04-01

405

Dynamic Isotope Power System, Integrated System Test  

NASA Astrophysics Data System (ADS)

The Dynamic Isotope Power System (DIPS) can supply three to four times more electrical power than Radioisotope Thermoelectric Generators (RTGs) for the same amount of Pu-238 fuel. The available electrical power can be used to drive propellant-efficient electric thrusters, which would enable and/or significantly enhance the capabilities of interplanetary missions. Because of this, the DIPS program has been reviewing the application of DIPS technology to the interplanetary missions in the 500 We to 1.0 kWe power range. Such a DIPS program would focus on completing an Integrated System Test (IST) of the DIPS in a simulated space environment. The DIPS IST would fully demonstrate DIPS integrated operation, long-term containment boundary integrity, and, most importantly, DIPS flight readiness. To reduce cost, schedule, and risk of the DIPS development, the design would use the DOE-developed Brayton Isotope Power System (BIPS) turboalternator compressor (TAC), which is currently being refurbished for use in the NASA-LeRC Solar Dynamic Ground Test Demonstration (SD GTD) Program. The DIPS IST, which would follow the SD GTD testing, would make use of common elements with the SD GTD wherever practical to reduce the IST cost and schedule. The components demonstrated in the IST would be flight prototypical except that full flight qualification would not be performed. For future interplanetary applications, the DIPS system would employ the identical TAC design demonstrated in the IST for all applications. Power level scalability would be achieved by scaling other loop components in a straightforward manner without technology development or requalification. This will significantly reduce costs while providing only a small scalability performance penalty.

Otting, William D.; Hunt, Maribeth E.; Ashe, Thomas L.

1994-07-01

406

Power system applications for PASC converter systems  

Microsoft Academic Search

This paper shows, using computer EMTP simulations, some preliminary results of applying pulse amplitude synthesis and control (PASC) technology to single-source voltage converter systems. The method can be applied to any single terminal pair source with appropriate modifications in power extraction interface and computer control program to match source and load impedance characteristics. The PASC realization as discussed here employs

M. K. Donnelly; R. M. Johnson

1995-01-01

407

Power system applications for PASC converter systems  

Microsoft Academic Search

This paper shows, using computer EMTP simulations, some preliminary results of applying pulse amplitude synthesis and control (PASC) technology to single-source level voltage converter system. The method can be applied to any single terminal pair source with appropriate modifications in power extraction interface and computer control program to match source and load impedance characteristics. The PASC realization as discussed here

M. K. Donnelly; R. M. Johnson

1994-01-01

408

Embeded reactive power compensator and power factor monitor system  

Microsoft Academic Search

The Reactive power compensator and monitor of Power factor system is designed based on ARM7, with function of long distant transmission. It monitors and measures alternation current parameters, such as the active and reactive electric energy, active and reactive power, voltage, current, power factor and other parameters. To realize reactive compensation, it can automatically switch shunt compensation capacitor by Thyristor

Gong Peng; Xu Shuhua; Gong Yue

2011-01-01

409

A Novel 500kW High-Speed Turbine PM Synchronous Generator Set for Distributed Power Generation  

NASA Astrophysics Data System (ADS)

The paper presents a power generation system based on the cogeneration of heat and electricity with a novel high speed turbogenerator. The machine consists of a single stage steam turbine and a directly coupled permanent magnet synchronous generator in one constructional unit. A PWM IGBT rectifier is the load to the generator and a PWM IGBT three-phase four-wire inverter feeds the power into the low voltage mains. In order to increase the turbine efficiency at light load, variable speed operation of the turbogenerator is realized. Different control schemes for mains parallel operation and stand alone operation are presented. The control schemes allow for the use of a lookup table based control with a speed-power-characteristic or for the use of a maximum power point tracker. Measurement results from the successfully tested turbogenerator set are presented.

Wendt, Sven; Benecke, Frank; Güldner, Henry

410

Explaining Power System Operation to Nonengineers  

Microsoft Academic Search

It is sometimes difficult to explain how a power system works, especially for people who have not studied electrical engineering. This article shows how the interactions of a power system and its components can be explained using the parallel with a tandem bicycle. The active power balance in the power system is modeled by the parallel of keeping a constant

Lennart Soder

2002-01-01

411

Comparing System-Level Power Management Policies  

Microsoft Academic Search

Reducing power consumption is a challenge to system designers. Portable systems, such as laptop computers and personal digital assistants (PDAs), draw power from batteries, so reducing power consumption extends their operating times. For desktop computers or servers, high power consumption raises temperature and deteriorates performance and reliability. Soaring energy prices and rising concern about the environmental impact of electronics systems

Yung-hsiang Lu; Giovanni De Micheli

2001-01-01

412

Integrated operation system for telecommunications power equipment  

Microsoft Academic Search

Nippon Telegraph and Telephone Corporation (NTT) has developed ALICE (Advanced power Plants Integrated maintenance Control systEm), an intelligent system for operating telecommunications power equipment. This system performs not only centralized supervision and control functions, but also information processing (relational database and data communications tasks) and diagnostic functions. It accomplishes diagnoses by applying expert system technology to power equipment. The system

H. Yamamura; I. Kase; H. Ikebe

1990-01-01

413

Power system dynamics influenced by a power electronic interface for variable speed wind energy conversion systems  

Microsoft Academic Search

A study of the influence of a wind energy conversion system on power system dynamics is presented in this paper. The wind energy conversion system is interfaced into a power system through a power electronic system including a voltage source converter (VSC) at the grid side. This paper investigates the system performance during a power system disturbance; a voltage sag

Z. Chen; Y. Hu

2004-01-01

414

Systems Geobiology Powers of 10  

NSDL National Science Digital Library

The newly emerging field of Systems Geobiology requires linkage of biological processes with geological processes across broad scales of time (nanoseconds to eons) and space (nanometers to light years). Students are asked to specifically identify the scales of time and space across which Systems Geobiology research needs to be completed. They do this by making direct observations of a field photograph taken at Mammoth Hot Springs in Yellowstone National Park. Students then translate 10 of their observations onto Powers of 10 charts. This is followed by a class discussion of their results on topics such as: What is missing? How will these analyses be synthesized across such broad scales?

Fouke, Bruce

415

Modeling Power Systems as Complex Adaptive Systems  

SciTech Connect

Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.

Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

2004-12-30

416

A distributed data acquisition and centralized data reduction system for flexible and efficient measurements  

NASA Astrophysics Data System (ADS)

The Diagnostic Instrumentation and Analysis Laboratory (DIAL) at Mississippi State University (MSU) is developing nonintrusive optical diagnostic instrumentation to characterize a magnetohydrodynamic (MHD) gas stream. The optical instrumentation systems are being developed, as part of the US Department of Energy (DOE) development program for the MHD power process, to measure gas temperature profiles, gas velocity and turbulence intensity profiles, and average particle size and particle size distribution, etc. since these instruments are primarily intended for field use, most of them have been developed as stand-alone systems, providing for ease of operation. Each stand-alone system, also called a target system, has the capability to acquire data, do a preliminary analysis, and display the result. The data from various instrumentation systems are logged to a central computer for detailed analysis, and to trace the history of instrument operation through an IEEE 488 based network. This system has been used with success for over five years in our field measurements at different locations in the US. Although the implementation presented here is based on a particular environment, the principles described are applicable in a variety of situations.

Phillip, T.; Jang, Ping-Rey; Benton, R. D.

417

Reliability Issues in Stirling Radioisotope Power Systems.  

National Technical Information Service (NTIS)

Stirling power conversion is a potential candidate for use in a Radioisotope Power System (RPS) for space science missions because it offers a multifold increase in the conversion efficiency of heat to electric power and reduced requirement of radioactive...

A. R. Shah J. G. Schreiber

2004-01-01

418

Reliability Issues in Stirling Radioisotope Power Systems.  

National Technical Information Service (NTIS)

Stirling power conversion is a potential candidate for use in a Radioisotope Power System (RPS) for space science missions because it offers a multifold increase in the conversion efficiency of heat to electric power and reduced requirement of radioactive...

J. Schreiber A. Shah

2005-01-01

419

Computer Center: CIBE Systems.  

ERIC Educational Resources Information Center

Differentiates between computer systems and Computers in Biological Education (CIBE) systems (computer system intended for use in biological education). Describes several CIBE stand alone systems: single-user microcomputer; single-user microcomputer/video-disc; multiuser microcomputers; multiuser maxicomputer; and local and long distance computer…

Crovello, Theodore J.

1982-01-01

420

Liquid metal solar power system  

SciTech Connect

A solar power system for cogenerating heat and electricity is disclosed. An improved solar collector includes a transparent reflector envelope through which a reflective liquid metal such as mercury is circulated. The liquid metal is preheated as it focuses solar radiation onto the receiver of the collector module. A baffle tube within the receiver is perforated to permit the circulation of working fluid out of the absorption chamber of the receiver into the narrow annulus between the baffle tube and the receiver wall, thereby promoting the rapid generation of vapor. The liquid metal vapor is discharged through the channel of a magnetohydrodynamic generator for producing electrical power in a first power generating stage. The liquid metal vapor is condensed and accumulated in a primary storage reservoir for driving a turbine generator in a second generating stage, thereby providing electrical power during periods of insufficient solar radiation. Liquid metal discharged from the turbine is accumulated in a secondary storage reservoir for supplying the solar collector module during periods of adquate solar radiation.

Tammen, B.J.

1984-06-19

421

Power Block, an adaptable spacecraft power control system  

NASA Astrophysics Data System (ADS)

The authors discuss power block electric power subsystem, a modular, expandable spacecraft power system which can be used in a wide range of spacecraft applications without non-recurring engineering. They describe the power block controller (PBC), a modular, microprocessor-based solar array power/battery charge controller. The PBC controls battery charging current by diverting unwanted solar array current to ground with the use of switching shunts and provides an interface among spacecraft solar arrays, a telemetry and command system, batteries, and a power distribution unit (PDU). The PBC's hardware, software, interfaces, and capabilities are described. It is pointed out that one power block can provide battery charge balance for a spacecraft containing up to 4 batteries with 3600 W of solar array output power. System efficiency at 3600 W is 99 percent (exclusive of PDU operation).

Baker, William; Kenig, Alfredo; Streeter, Gary

422

Scalability of OTR space nuclear power systems.  

National Technical Information Service (NTIS)

In this document, masses of the STAR-C power system and an optimized out-of-core thermionic reactor (OTR) power system versus power level are investigated. The impacts of key system parameters on system performance are also addressed. The STAR-C is mass c...

D. R. Gallup

1990-01-01

423

SOLERAS - Solar-Powered Water Desalination Project at Yanbu: PKI collectors performance  

Microsoft Academic Search

The seawater desalination pilot plant at Yanbu in Saudi Arabia is a unique experiment in which an indirect bulk freeze desalination process is integrated with a stand-alone solar cogeneration power plant. Thermal energy is stored in molten salt and is converted into shaft power required for primary refrigeration by a conventional steam engine. An absorption refrigeration unit is thermally driven

Hamad

1987-01-01

424

Electric power distribution and load transfer system  

SciTech Connect

This patent describes a power distribution system. It comprises at least two switch means for controlling the application of power from a power source to a power output; at least two current means for preventing reverse power flow through respective ones of switch means; and processing means for providing control signals to operate the switch means, effective to switch respective ones of the power sources between on and off states with respect to the power output.

Bradford, M.P.; Parkinson, G.W.; Grant, R.M.

1989-10-10

425

Power assist system with power-damped operation information feedbacking  

Microsoft Academic Search

This research considers a human-limb power assist system, which can feedback the power- damped operating forces to human. The system can easily suitable to a person without using EMG sensor and knowing limb's mass, viscosity and elasticity. The control method, assist rate and system unit are discussed in this paper. Lastly, experimental verification on the proposed approach is performed and

Yong Yu; Daisuke Yoshimitsu; Showzow Tsujio; Ryota Hayashi

2007-01-01

426

Machine Learning Applications to Power Systems  

Microsoft Academic Search

The recent developments in the power system area, i.e. the on-going liberalization of the energy markets, the pressing demands\\u000a for power system efficiency and power quality, the increase of dispersed, renewable generation and the growing number of interconnections\\u000a and power exchanges among utilities, dictate the need for improvements in the power system planning, operation and control.\\u000a At the same time,

Nikolaos Hatziargyriou

2001-01-01

427

Power System Harmonics Estimation and Monitoring  

Microsoft Academic Search

The existence of harmonics in power systems and their effects have led to numerous issues of electric power quality. The IEEE Standard 519 is being revised and upgraded from a guide to a recommended practice in order to set limits on harmonic distortion and to ensure a high power quality. Thus, the measurement of harmonics in power system has assumed

Husam M. Beides; G. T. Heydt

1992-01-01

428

Dynamic state estimation of power system harmonics  

Microsoft Academic Search

The application of solid state drives in power systems has led to numerous issues of electric power quality. Many of these issues are related to harmonics in power systems which threaten the quality of electric power supplied to the consumer. The upgrading of the IEEE guide that set limits on harmonic injections added additional focus to the subject of harmonic

Husam Mohamed Beides

1991-01-01

429

Aspheric Cassegrain Laser Power Amplifier System.  

National Technical Information Service (NTIS)

This patent application is directed to a power amplifier system which extracts high power optical radiation from a laser media. The system includes a gas dynamic, E-beam, or chemical laser from which power is extracted. The extracted power is as near diff...

R. R. Fluhr S. T. Hanley R. B. Brown

1975-01-01

430

Stand-alone cage for posterior lumbar interbody fusion in the treatment of high-degree degenerative disc disease: design of a new device for an “old” technique. A prospective study on a series of 116 patients  

Microsoft Academic Search

Chronic lumbar pain due to degenerative disc disease affects a large number of people, including those of fully active age.\\u000a The usual self-repair system observed in nature is a spontaneous attempt at arthrodesis, which in most cases leads to pseudoarthrosis.\\u000a In recent years, many possible surgical fusion techniques have been introduced; PLIF is one of these. Because of the growing

Francesco Costa; Marco Sassi; Alessandro Ortolina; Andrea Cardia; Roberto Assietti; Alberto Zerbi; Martin Lorenzetti; Fabio Galbusera; Maurizio Fornari

2011-01-01

431

Emergency Power For Critical Items  

NASA Astrophysics Data System (ADS)

Natural disasters, such as hurricanes, floods, tornados, and tsunami, are becoming a greater problem as climate change impacts our environment. Disasters, whether natural or man made, destroy lives, homes, businesses and the natural environment. Such disasters can happen with little or no warning, leaving hundreds or even thousands of people without medical services, potable water, sanitation, communications and electrical services for up to several weeks. In our modern world, the need for electricity has become a necessity. Modern building codes and new disaster resistant building practices are reducing the damage to homes and businesses. Emergency gasoline and diesel generators are becoming common place for power outages. Generators need fuel, which may not be available after a disaster, but Photovoltaic (solar-electric) systems supply electricity without petroleum fuel as they are powered by the sun. Photovoltaic (PV) systems can provide electrical power for a home or business. PV systems can operate as utility interactive or stand-alone with battery backup. Determining your critical load items and sizing the photovoltaic system for those critical items, guarantees their operation in a disaster.

Young, William R.

2009-07-01

432

High Power Pulse Energy System Concept.  

National Technical Information Service (NTIS)

New advances in capacitor technology create exciting opportunities in size and weight reduction for high-power, pulse energy systems having a broad range of applications. Characteristics of a proposed high power pulse energy system, formed by combining a ...

H. L. Lee G. Mason K. Kern

1988-01-01

433

A power system for a microsatellite  

NASA Astrophysics Data System (ADS)

A power system for a microsatellite was designed for the Space Technology Research Vehicle (STRV-1) mainly aimed at technology demonstration experiments and studies of radiation effects and planned to be launched into geostationary transfer orbit. The low average solar array power (25 W) and the small volume allocation of the power system electronics (2.8 dm cubed) became a challenge when trying to produce a failure tolerant power system. The power system elements: shunt regulator, battery discharge regulator, power distribution, solar array, battery, and their management and protection are described. Power system performance and growth potential are also discussed. After several simplification iteractions, a modular power electronics system with a high degree of failure tolerance, with a mass less than 2.5 kg and an internal power consumption less than 3 W was developed.

Olsson, Dan

1993-01-01

434

SITE ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

The Site Electrical Power System receives and distributes utility power to all North Portal site users. The major North Portal users are the Protected Area including the subsurface facility and Balance of Plant areas. The system is remotely monitored and controlled from the Surface Operations Monitoring and Control System. The system monitors power quality and provides the capability to transfer between Off-Site Utility and standby power (including dedicated safeguards and security power). Standby power is only distributed to selected loads for personnel safety and essential operations. Security power is only distributed to essential security operations. The standby safeguards and security power is independent from all other site power. The system also provides surface lighting, grounding grid, and lightning protection for the North Portal. The system distributes power during construction, operation, caretaker, and closure phases of the repository. The system consists of substation equipment (disconnect switches, breakers, transformers and grounding equipment) and power distribution cabling from substation to the north portal switch gear building. Additionally, the system includes subsurface facility substation (located on surface), switch-gear, standby diesel generators, underground duct banks, power cables and conduits, switch-gear building and associated distribution equipment for power distribution. Each area substation distributes power to the electrical loads and includes the site grounding, site lighting and lightning protection equipment. The site electrical power system distributes power of sufficient quantity and quality to meet users demands. The Site Electrical Power System interfaces with the North Portal surface systems requiring electrical power. The system interfaces with the Subsurface Electrical Distribution System which will supply power to the underground facilities from the North Portal. Power required for the South Portal and development side activities of the subsurface facility will be provided at the South Portal by the Subsurface Electrical Distribution System. The Site Electrical Power System interfaces with the Off-Site Utility System for the receipt of power. The System interfaces with the Surface Operations Monitoring and Control System for monitoring and control. The System interfaces with MGR Site Layout System for the physical location of equipment and power distribution.

E.P. McCann

1999-04-16

435

Space nuclear power system studies in France  

Microsoft Academic Search

A program is described to investigate the feasibility, development, cost, and lead time of 20-200-kWe space nuclear power system adapted to powering different space missions as space-based radar for earth observation, LEO-GEO orbit-transfer vehicle and space transportation systems using electrical propulsion (200-400 kWe). Several concepts of nuclear power systems are studied including: a 200 kWe power system operating at very

F. Carre; J. Delaplace; E. Proust; Z. Tilliette

1991-01-01

436

Dc power supplies and hard-tube power conditioning systems  

SciTech Connect

In this lecture, we shall discuss some of the major characteristics of dc power supplies and hard-tube pulsers, along with many of their PCS limiting properties and several of the more powerful vacuum tubes that are currently available for larger hard-tube pulsers systems. The initial topic will be elementary dc power supplies, operating with standard 60 Hz AC input power. The full-wave bridge design will be discussed in detail, illustrating the majority of the significant circuit parameters.

Sarjeant, W.J.

1980-01-01

437

Frequency stability issues for islanded power systems  

Microsoft Academic Search

Frequency stability has not necessarily been a major problem for the majority of power systems in the past. However, for economic and environmental reasons, power systems are now operated closer to stability limits to maximise the use of the existing networks. Therefore, introduction of new, more efficient and renewable generation technologies, and their effect on the power system must be

Jonathan Horne; Damian Flynn; Tim Littler

2004-01-01

438

Advanced survivable space solar power system  

SciTech Connect

This patent describes a solar power system. It comprises: generally planar support means for providing support to the solar power system; heat pipe wall means, located along the outer edges of the support means and perpendicular with respect to the support means, for radiating waste heat away form the solar power system; foldable strut means; and transducer means.

Blackman, J.B.; Stone, K.W.; Gerrick, R.A.; Jones, N.E.

1992-10-13

439

Dynamic modeling of power electronic systems  

Microsoft Academic Search

Simulation and modeling provide a fast and cost-efficient way for sophisticated analysis and design of power converters. This paper presents various approaches of dynamic modeling of power electronic systems. It discusses practical technical issues in simulation and system modeling. Two demonstrative examples, the power converters in healthcare and energy systems, by using different simulation package and platforms are provided.

Luis Garcés; Xianghui Huang; Chunchun Xu; Paul Szczesny

2009-01-01

440

Impact of Security on Power Systems Operation  

Microsoft Academic Search

This paper reviews the status of security analyses in vertically integrated utilities and discusses the impact of system security on the operation and the planning of restructured power systems. The paper is focused on the static security rather than the dynamic security of power systems. The paper also discusses assumptions, functions, and calculation tools that are considered for satisfying power

MOHAMMAD SHAHIDEHPOUR; F. Tinney; Yong Fu

2005-01-01

441

Generation control in small isolated power systems  

Microsoft Academic Search

Recently, interest in isolated small power systems is rapidly increasing. This interest is due to the fact that larger power plants are economically unfeasible in many regions due to increasing system and fuel costs. When the system operates in isolation then load tracking problem arises which can cause voltage and frequency problems. One possible solution to keep power balance in

M. Milosevic; G. Andersson

2005-01-01

442

Using SPICE for power system simulations  

Microsoft Academic Search

Power system simulation software is a useful tool for teaching the fundamentals of power system design and operation. However, existing commercial packages are not ideal for teaching work-based students because of high-cost, complexity of the software and licensing restrictions. This paper describes a set of power systems libraries that have been developed for use with the free, studentedition of a

Andrew Cross; Dani Strickland

2011-01-01

443

Power management for hybrid fuel cell system  

Microsoft Academic Search

This paper proposes a power management control scheme for hybrid fuel cell power system. The hybrid fuel cell system consists of a fuel cell, an isolated unidirectional converter, a bi-directional converter, an inverter, and a battery. The fuel cell powers the steady state energy and the battery compensates the dynamic energy. They need to work together to ensure the system

Ke Jin; Xinbo Ruan; Mengxiong Yang; Min Xu

2008-01-01

444

ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

The purpose of this revision of the System Description Document (SDD) is to establish requirements that drive the design of the electrical power system and their bases to allow the design effort to proceed to License Application. This SDD is a living document that will be revised at strategic points as the design matures over time. This SDD identifies the requirements and describes the system design as they exist at this time, with emphasis on those attributes of the design provided to meet the requirements. This SDD has been developed to be an engineering tool for design control. Accordingly, the primary audience are design engineers. This type of SDD leads and follows the design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential to performing the design process. This SDD follows the design with regard to the description of the system. The description provided in the SDD is a reflection of the results of the design process to date. Functional and operational requirements applicable to this system are obtained from ''Project Functional and Operational Requirements'' (F&OR) (Siddoway, 2003). Other requirements to support the design process have been taken from higher level requirements documents such as ''Project Design Criteria Document'' (PDC) (Doraswamy 2004), the fire hazards analyses, and the preclosure safety analysis. The above mentioned low-level documents address ''Project Requirements Document'' (PRD) (Canori and Leitner 2003) requirements. This SDD includes several appendices with supporting information. Appendix B lists key system charts, diagrams, drawings, and lists; and Appendix C is a list of system procedures.

M. Maniyar

2004-06-22

445

Captive Water Current Power System  

SciTech Connect

Current energy is converted into shaft power in two stages; First, buoyant power units with stationary hydrofoil wings reach faster than the current speed by sweeping out a captive path. Second, turbines at said power units convert the fast relative local current into shaft power. Power units sweeping along the water surface, using cycloidal turbine methods, as well as power units sweeping on a submerged path, using axial flow turbine methods, are described.

Wuenscher, H. F.; Wuenscher, H. A.

1984-01-31

446

An Open Source Power System Analysis Toolbox  

Microsoft Academic Search

This paper describes the Power System Analysis Toolbox (PSAT), an open source Matlab and GNU\\/Octave-based software package for analysis and design of small to medium size electric power systems. PSAT includes power flow, continuation power flow, optimal power flow, small-signal stability analysis, and time-domain simulation, as well as several static and dynamic models, including nonconventional loads, synchronous and asynchronous machines,

Federico Milano

2005-01-01

447

Optimum Evaluation of Reactive Power Requirements in Power Distribution Systems  

Microsoft Academic Search

This paper presents three methodologies for determining optimum locations and magnitudes of reactive power compensation in power distribution systems. Method I and Method II are suitable for complex distribution systems with a combination of both radial and ring-main feeders and having different voltage levels. Method III is suitable for low-tension single voltage level radial feeders. Method I is based on

D. Thukaram; K. Parthasarathy; B. S. Ramakrishna IYENGAR

1985-01-01

448

Virtual SCADA Simulation System for Power Substation  

Microsoft Academic Search

With the recent development of industrial computing systems and human machine interface software packages, power systems research and development engineers ceased the opportunity to come up with virtual simulation tools to emulate the operation of power systems. The paper describes the development of a virtual SCADA (V-SCADA) system tool for testing and training purposes. Design engineers can test their system

K. W. Darwish; A. R. Al Ali; R. Dhaouadi

2007-01-01

449

Space Weather Situational Awareness for Power Systems  

NASA Astrophysics Data System (ADS)

Space weather, through the production of geomagnetic disturbances, has the potential to cause problems to the operation of high voltage power transmission networks on the ground. A space weather situational awareness tool has been developed for Canadian power utilities to provide power system operators with the information to make informed decisions to maintain system integrity during a space weather event. During geomagnetic disturbances electric currents induced in the power grid can cause partial satuartion of transformers causing increased harmonics and reactive power consumption that can cause misoperation of relays and voltage sags that interfere with system operation. This presentation will describe the development of a system for real-time simulation of geomagnetically induced currents in a power network and how this is being integrated with power system information into a comprehensive situation awareness tool for use in power system control centres.

Boteler, David; Marti, Luis

2012-07-01

450

Tailoring SCADA systems for standby power applications  

SciTech Connect

Supervisory control and data acquisition (SCADA) systems have been used by the manufacturing and process industries and many electric power utilities for energy management systems, including economic dispatch and the interconnection processing of energy. However, the use of SCADA in smaller power generation systems is not quite so wide spread. This article explains how a SCADA system was custom developed for a stand-by power generation system recently installed in a commercial office building.

Leslie, D.; Hlushko, A.; Abughazaleh, S.; Garza, F.

1994-04-01

451

EMERY BIOMASS GASIFICATION POWER SYSTEM  

SciTech Connect

Emery Recycling Corporation (now Emery Energy Company, LLC) evaluated the technical and economical feasibility of the Emery Biomass Gasification Power System (EBGPS). The gasifier technology is owned and being developed by Emery. The Emery Gasifier for this project was an oxygen-blown, pressurized, non-slagging gasification process that novelly integrates both fixed-bed and entrained-flow gasification processes into a single vessel. This unique internal geometry of the gasifier vessel will allow for tar and oil destruction within the gasifier. Additionally, the use of novel syngas cleaning processes using sorbents is proposed with the potential to displace traditional amine-based and other syngas cleaning processes. The work scope within this project included: one-dimensional gasifier modeling, overall plant process modeling (ASPEN), feedstock assessment, additional analyses on the proposed syngas cleaning process, plant cost estimating, and, market analysis to determine overall feasibility and applicability of the technology for further development and commercial deployment opportunities. Additionally, the project included the development of a detailed technology development roadmap necessary to commercialize the Emery Gasification technology. Process modeling was used to evaluate both combined cycle and solid oxide fuel cell power configurations. Ten (10) cases were evaluated in an ASPEN model wherein nine (9) cases were IGCC configurations with fuel-to-electricity efficiencies ranging from 38-42% and one (1) case was an IGFC solid oxide case where 53.5% overall plant efficiency was projected. The cost of electricity was determined to be very competitive at scales from 35-71 MWe. Market analysis of feedstock availability showed numerous market opportunities for commercial deployment of the technology with modular capabilities for various plant sizes based on feedstock availability and power demand.

Benjamin Phillips; Scott Hassett; Harry Gatley

2002-11-27

452

Photovoltaic Power Conditioning System With Line Connection  

Microsoft Academic Search

A photovoltaic (PV) power conditioning system (PCS) with line connection is proposed. Using the power slope versus voltage of the PV array, the maximum power point tracking (MPPT) controller that produces a smooth transition to the maximum power point is proposed. The dc current of the PV array is estimated without using a dc current sensor. A current controller is

Jung-Min Kwon; Kwang-Hee Nam; Bong-Hwan Kwon

2006-01-01

453

Low power systems for wireless microsensors  

Microsoft Academic Search

Low power wireless sensor networks pro- vide a new monitoring and control capability for civil and military applications in transportation, manufactur- ing, biomedical, environmental management, and safety and security systems. Wireless microsensor network nodes, operating at average and peak power levels con- strained by compact power sources, offer a range of important challenges for low power methods. This paper reports

K. Bult; Amit Burstein; D. Chang; Michael J. Dong; M. Fielding; E. Kruglick; J. Ho; F. Lin; T. H. Lin; William J. Kaiser; H. Marcy; R. Mukai; Phyllis R. Nelson; F. L. Newburg; Kristofer S. J. Pister; Gregory J. Pottie; Henry Sanchez; Oscar M. Stafsudd; K. Tan; S. Xue; J. Yao

1996-01-01

454

Applications of power electronics in railway systems  

Microsoft Academic Search

Power system interface with electrified railways (ER), auxiliary power, hybrid trains, electromagnetic interface (EMI) and traction are reviewed in this paper for diesel electric trains and ERs. Auxiliary power supply is a low voltage AC\\/DC power supply for onboard devices with an important consideration for safety equipment. In diesel electric railways because of variable train speed, a sort of compromise

Arash A. Boora; Firuz Zare; Arindam Ghosh; Gerard Ledwich

2007-01-01

455

Task 3.14 -- Demonstration of technologies for remote power generation in Alaska. Semi-annual report, July 1--December 31, 1995  

SciTech Connect

The overall goal of this project is a site specific demonstration of a small, environmentally acceptable electric generating system fueled on indigenous fuels and waste materials to serve the microgrid or stand alone power distribution systems typical of remote, isolated Alaska Native communities. The objective of the project is to develop a commercialization plan that includes an analysis of the quantity, quality, and cost of the available fuels; a mapping of the electricity and district heating needs of a selected community, including electrical distribution layout and interconnecting steam piping; a step by step review of the environmental regulations and permit applications that need to be met; and a preliminary design and budget for the demonstration of a 0.5 to 6 MWe power system to be completed by the Energy and Environmental Research Center (EERC) in a manner that provides technical and regulatory readiness to proceed with implementation of the demonstration.

NONE

1997-08-01

456

45 CFR 155.1065 - Stand-alone dental plans.  

Code of Federal Regulations, 2012 CFR

...REQUIREMENTS RELATING TO HEALTH CARE ACCESS EXCHANGE...STANDARDS UNDER THE AFFORDABLE CARE ACT Exchange...Certification of Qualified Health Plans § 155...dental essential health benefit as defined...J) of the Affordable Care Act,...

2012-10-01

457

Adaptive relay setting for stand-alone digital distance protection  

Microsoft Academic Search

Reach accuracy of a distance relay on transmission lines is adversely affected by fault resistance combined with remote-end infeed which is not measurable at the relaying point. Different network conditions correspond to different remote-end infeed behavior and in conventional setting a safety margin is necessary so as to avoid maloperation. In this paper an adaptive setting concept which can overcome

Y. Q. Xia; K. K. Li; A. K. David

1994-01-01

458

Stand-Alone versus Integrated Critical Thinking Courses  

ERIC Educational Resources Information Center

|For well over 25 years, critical thinking has been declared an educational ideal. However, though institutions are committed to teaching "critical thinking" (CT), there are numerous important questions that need careful treatment if this goal is to be met. First, the faculties must arrive at a shared understanding of what they mean by the…

Hatcher, Donald L.

2006-01-01

459

Stand-Alone versus Integrated Critical Thinking Courses  

ERIC Educational Resources Information Center

For well over 25 years, critical thinking has been declared an educational ideal. However, though institutions are committed to teaching "critical thinking" (CT), there are numerous important questions that need careful treatment if this goal is to be met. First, the faculties must arrive at a shared understanding of what they mean by the phrase…

Hatcher, Donald L.

2006-01-01

460

Line voltage stability calculations in power systems  

Microsoft Academic Search

Voltage instability and voltage collapses are increasingly attracting worldwide interest. Operating power system closer to its stability limits, transferring large amounts of powers from long distance and an inadequate supply of reactive power contribute to system voltage instability and eventually to voltage collapse. Accurate calculations of voltage stability, precise prediction of voltage collapse points and low time consumption of procedures

F. A. Althowibi; M. W. Mustafa

2010-01-01

461

Power system problems solved by FACTS devices  

Microsoft Academic Search

AC power transmission started in the late 19th century from low voltage levels and restricted supply areas and changed over time towards larger distances and higher power transfers. Increased transmission voltages have been one important measure making systems capable of meeting growing demands. While in the early days power systems had high reserve capacities economical and environmental constraints gradually increased

H. K. Tyll; Frank Schettler

2009-01-01

462

NASA Radioisotope Power Systems Program Update  

Microsoft Academic Search

The use of Radioisotope Power Systems (RPS) represents a critical capability for exploration of the Solar System. RPS have been used for decades to power deep space missions and sometimes for the operation of landers or rovers on Mars. Modest power needs (5 AU) make them attractive, and, in most cases,

B. Alan Harmon; David B. Lavery

2008-01-01

463

NASA Radioisotope Power Systems Program Update  

Microsoft Academic Search

The use of Radioisotope Power Systems (RPS) represents a critical capability for exploration of the Solar System. RPS have been used for decades to power deep space missions and sometimes for the operation of landers or rovers on Mars. Modest power needs (5 AU) make them attractive, and, in most cases, essential for a variety of missions. Even close by,

B. Alan Harmon; David B. Lavery

2008-01-01

464

Hydrogen turbine power conversion system assessment  

Microsoft Academic Search

A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three

D. E. Wright; A. D. Lucci; J. Campbell; J. C. Lee

1978-01-01

465

Lightning risk assessment of power systems  

Microsoft Academic Search

The work presented in this paper is a result of efforts to develop technically high-interest materials on lightning risk analysis aimed at teaching power systems. The paper describes series of case studies involving lightning effects on various parts of a power system including substations, transmission lines, and wind turbine systems. First, the paper defines the problem confronting protection systems engineers,

Riadh W. Y. Habash; Voicu Groza

2010-01-01

466

Seismic Performance Analysis of Electric Power Systems  

Microsoft Academic Search

This study carries out a seismic system performance analysis on Los Angeles Department of Water and Power's electric power system, given inventory data, system configuration and fragility information with or without rehabilitation. The analysis requires the delicate coordination of various technologies involving interpretation and manipulation of sophisticated and voluminous inventory data, utilization of highly specialized computer codes for systems analysis,

Masanobu Shinozuka

467

Expert Systems for Power System Dispatch: Pre-Study.  

National Technical Information Service (NTIS)

This pre-study will try to explain the concept of expert system and discuss if expert system technology is of any use for Vattenfall, the Swedish State Power Board, within the field of power system dispatch. Power system dispatch and control including con...

L. Berglund

1987-01-01

468

Energy storage for nuclear burst power systems  

NASA Astrophysics Data System (ADS)

This analysis indicated that the inclusion of storage in sprint power systems can yield overall system mass savings. Thermal storage and regenerable electrical storage (using fuel cells, batteries and flywheels) can play a role in various power system concepts. The cost to close the power cycle can be modest. Given the large uncertainties associated with the acceptability of effluent clouds in sprint operations, it would appear reasonable to develop the closed cycle/storage systems in parallel.

Olszewski, Mitchell; Morris, David G.

469

DOE/SCS Power Systems Development Facility.  

National Technical Information Service (NTIS)

The use of coal for power generation has come under increasing environmental scrutiny over the past five years. Advances in coal-based power generation technology will continue to develop towards systems that have high efficiency, environmental superiorit...

Z. U. Haq T. E. Pinkston R. E. Sears P. Vimalchand

1993-01-01

470

Improved refractories for IGCC power systems  

SciTech Connect

Certain advantages make coal gasification a key element in the US Department of Energy's Vision 21 power system. However, issues of reliability and gasifier operation economics need to be resolved before gasification is widely adopted by the power generation industry.

Dogan, Cynthia P.; Kwong, Kyei-Sing; Bennet, James P.; Chinn, Richard E.; Dahlin, Cheryl L.

2002-09-01

471

Pulsed high power fiber laser systems  

Microsoft Academic Search

The master-oscillator power-amplifier approach, cladding pumping technology and large mode area fibers provide a route to compact and efficient pulsed fiber laser systems with high beam quality and high output powers

A. Malinowski; J. H. V. Price; F. He; P. Dupriez; H. D. Foreman; A. C. Tropper; J. Nilsson; D. J. Richardson

2006-01-01

472

Hydrogen Turbine Power Conversion System Assessment.  

National Technical Information Service (NTIS)

A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and t...

D. E. Wright A. D. Lucci J. Campbell J. C. Lee

1978-01-01

473

Power storage system for electric railway  

SciTech Connect

This invention relates to a power storage system for electric railway which comprises a motor-generator connected to a power system for feeding an electric vehicle with electric power, and a flywheel coupled to the motor-generator, and in which the motor-generator is allowed to store the electric power and thereafter discharge it in correspondence with approach of the electric vehicle to a predetermined running section and running thereof in the section.

Kawamura, T.

1985-06-11

474

Unified energy conversion, power systems and power electronics lab  

Microsoft Academic Search

This paper introduces an unified laboratory consisting of power systems, power electronics and energy conversions at Oklahoma State University-Tulsa. It presents more on digital data acquisition (DAQ), and virtual instrumentation (VI), the base of our unified lab. The general design of lab setup is described here, and unique designs of front panels and motor mount are discussed in detail. Some

Seungwon An; Swakshar Ray; Thomas W. Gedra

2002-01-01

475

Power electronics as efficient interface in dispersed power generation systems  

Microsoft Academic Search

The global electrical energy consumption is rising and there is a steady increase of the demand on the power capacity, efficient production, distribution and utilization of energy. The traditional power systems are changing globally, a large number of dispersed generation (DG) units, including both renewable and nonrenewable energy sources such as wind turbines, photovoltaic (PV) generators, fuel cells, small hydro,

Frede Blaabjerg; Zhe Chen; S. B. Kjaer

2004-01-01

476

78 FR 39280 - Integrated System Power Rates  

Federal Register 2010, 2011, 2012, 2013

...facilities. The Administrator of Southwestern...proposed Integrated System rates, which are...guidelines, the Administrator of Southwestern...using existing system rates.\\1\\ This...proceeding, the Administrator will submit the finalized Integrated System Power...

2013-07-01

477

Advanced power conditioning for maglev systems  

NASA Astrophysics Data System (ADS)

The final report contains parametric scaling data and computer models of power conditioning equipment applicable to the design of an advanced maglev system. The power conditioning topologies were selected based on data from a literature search, on characteristics of present power semiconductor technology devices, and on actual performance characterization of designs using a circuit analysis program. The analyses show that GTO's are the best switches for traction drives, input power conditioning equipment, and the braking chopper. At lower power levels, as required for auxiliary power and superconducting coil power conditioning, the IGBT appeared to be the best switch.

Nerem, A.; Bowles, E. E.; Chapelle, S.; Callanan, R. J.

1992-08-01

478

Power system protection-power monitoring-data logging-remote interrogation system  

Microsoft Academic Search

A power monitoring system is described which uses microprocessor technology to provide protection, real-time status displays, event logging, and power management and control for industrial AC power distribution and generation systems. The system uses an industrial-grade host personal computer to monitor various device communication systems. Each device communication system consists of a display and monitoring unit connected by a single

B. G. Bailey

1990-01-01

479

Operation experience of a solar- and wind-powered desalination demonstration plant  

Microsoft Academic Search

The present work outlines the designing, erection and operation process of a stand-alone desalination plant powered by both solar photovoltaic and wind energy. Such a plant will serve small isolated communities in remote areas devoid of water resources. A specially customized code was built to simulate the operation of the installation in order to allow appropriate choice of components specifications.

Dan Weiner; David Fisher; Eduard J. Moses; Baruch Katz; Giora Meron

2001-01-01

480

Distributed control system approach for a unified power system  

Microsoft Academic Search

This paper presents an approach for applying distributed control system, DCS for a unified power system. It is well known that the distributed control system is usually serves to control, largescale systems, such as unified power systems, production lines in factories, airplanes, and airport earth services. The proposed distributed control system consists of hardware software and a number of controllers

M. Z. El-Sadek; A. M. Hemeida; M. A. Abelwahab; A. Alkosy; S. A. Younies

2004-01-01

481

Nonlinear and hybrid dynamics in power system  

NASA Astrophysics Data System (ADS)

In these years, power system is strongly interested from the viewpoint of unifying physical networks by information and communication technology (ICT). Fundamentally power system is highly nonlinear coupled system with control system to stabilize the system behavior around an equilibrium operating state. However, the analysis based on continuous dynamics is not enough to understand the practical system and its dynamics. In this manuscript, we are focusing the hybrid structure and the nonlinear behavior.

Hikihara, Talashi; Yoshihiko, Susuki

2011-04-01

482

The Failure Analysis in Traction Power System  

NASA Astrophysics Data System (ADS)

This paper presents a failure analysis of traction power systems. The electric railway consists of traction power systems, various vehicles, operating equipment, track, overhead line and electric equipment. It is a fundamental function of traction power systems that they supply customers with acceptable reliability and high quality power. Perhaps the most commonly used reliability assessment for railway systems has been the failure analysis of the traction signal system. The reliability assessment of traction power systems has also been an indispensable issue for reliability assessment. This paper deals with the classification of railway accidents caused by electrification problems, the estimation of failure rate in power equipments and failure analysis using fault trees. In study cases, the fault tree method for failure analysis is applied to railway substations in South Korea.

Kim, Hyungchul; Heo, Guk-Bum; Lee, Hyungwoo; Kim, Dong Jin; Kim, Jin O.

2008-10-01

483

Power quality investigations of VSCF aircraft electric power systems  

Microsoft Academic Search

A model of the advanced aircraft electric power system is developed and studied under variable-speed constant-frequency (VSCF) operation. The frequency of the generator's output voltage is varied from 400-Hz to 800-Hz for different loading case-studies. Non-linear DC loads in addition to the different passive and dynamic AC loads are included in the simulation of the VSCF aircraft electric power system.

A. Eid; H. El-Kishky; M. Abdel-Salam; T. El-Mohandes

2010-01-01

484

Cooperative converters in power electronic systems  

Microsoft Academic Search

The specifications of power electronic systems are becoming ever more exigent - better performance (dynamic and steady state), increased efficiency, reliability, and quality, and decreased power rating, size (volume and weight), and cost. One strategy for the overall improvement of these systems is to use various cooperating converters with the system functions being shared among them, optimizing each converter for

E. Romero-Cadaval; M. I. Milane?s-Montero

2010-01-01

485

Vulnerability assessment and control of power system  

Microsoft Academic Search

With power grids considered national security matters, the reliable operation of the system is of top priority to utilities. This concern is amplified by the utility's deregulation, which increases the system's openness while simultaneously decreasing the applied degree of control. Vulnerability Assessment (VA) deals with the power system's ability to continue to provide service in case of an unforeseen catastrophic

Mohamed A. El-Sharkawi

2002-01-01

486

A nuclear power plant system engineering workstation  

Microsoft Academic Search

System engineers offer an approach for effective technical support for operation and maintenance of nuclear power plants. System engineer groups are being set up by most utilities in the United States. Institute of Nuclear Power operations (INPO) and U.S. Nuclear Regulatory Commission (NRC) have endorsed the concept. The INPO Good Practice and a survey of system engineer programs in the

J. H. Mason; J. W. Crosby

1989-01-01

487

Advanced Aircraft Secondary Power System Design  

Microsoft Academic Search

This paper describes the requirements, the secondary power system design, and the results of a trade study for an Advanced Aircraft Secondary Power System Design (AASPSD). AASPSD is an Air Force funded contract performed by The Boeing Company. The aircraft selected for this study was a Mach 6 vehicle. The three AASPSD configurations studied were a conventional system having hydraulic

E. J. Woods; C. S. Rubertus; I. S. Mehdi

1990-01-01

488

Joint power control in cellular radio systems  

Microsoft Academic Search

Transmitter power control has proven to be an efficient method to control interference and to improve spectrum utilization in cellular and personal communication systems. Previous results have shown that a significantly higher capacity may be reached, even if the system is subject to (practical) power constraints. Since in most cellular systems a duplex link is required, adequate transmission quality has

Magnus Frodighl; Jens Zander

1995-01-01

489

Magnetic mirror fusion power systems  

NASA Astrophysics Data System (ADS)

The magnetic mirror plasma confinement concept has characteristics conducive to attractive central station power plants; namely linear geometry, high fusion power density, steady state, and direct conversion of plasma energy to electricity. Recent advances in mirror physics-tandem mirror plugs with thermal barriers, enhanced microstability from sloshing ions, drift pumping have improved performance to the point where technically viable commercial reactors can be designed now and economic power production is envisioned by evolution and maturation of fusion technology.

Gordon, J. D.; Logan, B. G.

1983-09-01

490

ADVANCED POWER SYSTEMS ANALYSIS TOOLS  

SciTech Connect

The use of Energy and Environmental Research Center (EERC) modeling tools and improved analytical methods has provided key information in optimizing advanced power system design and operating conditions for efficiency, producing minimal air pollutant emissions and utilizing a wide range of fossil fuel properties. This project was divided into four tasks: the demonstration of the ash transformation model, upgrading spreadsheet tools, enhancements to analytical capabilities using the scanning electron microscopy (SEM), and improvements to the slag viscosity model. The ash transformation model, Atran, was used to predict the size and composition of ash particles, which has a major impact on the fate of the combustion system. To optimize Atran key factors such as mineral fragmentation and coalescence, the heterogeneous and homogeneous interaction of the organically associated elements must be considered as they are applied to the operating conditions. The resulting model's ash composition compares favorably to measured results. Enhancements to existing EERC spreadsheet application included upgrading interactive spreadsheets to calculate the thermodynamic properties for fuels, reactants, products, and steam with Newton Raphson algorithms to perform calculations on mass, energy, and elemental balances, isentropic expansion of steam, and gasifier equilibrium conditions. Derivative calculations can be performed to estimate fuel heating values, adiabatic flame temperatures, emission factors, comparative fuel costs, and per-unit carbon taxes from fuel analyses. Using state-of-the-art computer-controlled scanning electron microscopes and associated microanalysis systems, a method to determine viscosity using the incorporation of grey-scale binning acquired by the SEM image was developed. The image analysis capabilities of a backscattered electron image can be subdivided into various grey-scale ranges that can be analyzed separately. Since the grey scale's intensity is dependent on the chemistry of the particle, it is possible to map chemically similar areas which can also be related to the viscosity of that compound at temperature. A second method was also developed to determine the elements associated with the organic matrix of the coals, which is currently determined by chemical fractionation. Mineral compositions and mineral densities can be determined for both included and excluded minerals, as well as the fraction of the ash that will be represented by that mineral on a frame-by-frame basis. The slag viscosity model was improved to provide improved predictions of slag viscosity and temperature of critical viscosity for representative Powder River Basin subbituminous and lignite coals.

Robert R. Jensen; Steven A. Benson; Jason D. Laumb

2001-08-31

491

Power system design issues for smart materials  

Microsoft Academic Search

The effect of bidirectional power flow on the power distribution system of an aircraft is addressed in this paper. The active vibration control problem of the tail surface of an aircraft using piezoelectric actuators is chosen to motivate the study presented. A simple dynamic model of the tail surface is developed. A current controlled switched-mode power amplifier is used to

Douglas K. Lindner; Sriram Chandrasekaran

1999-01-01

492

Overlaod Protection System for Power Inverter.  

National Technical Information Service (NTIS)

An overload protection system for a power inverter utilizes a first circuit for monitoring current to the load from the power inverter to detect an overload and a control circuit to shut off the power inverter when an overload condition is detected. At th...

S. Nagano

1976-01-01

493

System design of ELITE power processing unit  

Microsoft Academic Search

The Electric Propulsion Insertion Transfer Experiment (ELITE) is a space mission planned for the mid 1990s in which technological readiness will be demonstrated for electric orbit transfer vehicles (EOTVs). A system-level design of the power processing unit (PPU), which conditions solar array power for the arcjet thruster, was performed to optimize performance with respect to reliability, power output, efficiency, specific

David J. Caldwell

1991-01-01

494

Load control system for nuclear power plant  

Microsoft Academic Search

A load control system for a boiling water reactor power plant. A recirculating pump speed demand signal and a total steam flow demand signal are derived on the basis of combination of a first control signal produced in accordance with a power difference signal representative of difference between an actual value of an output power of an electric generator and

J. Tanji; M. Izumi

1984-01-01