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1

Generating capacity adequacy evaluation of small stand-alone power systems containing solar energy  

Microsoft Academic Search

This paper presents a time sequential simulation method for generating capacity adequacy evaluation of small stand-alone power systems containing solar energy (PSCSE) operating in parallel with battery storage. The reliability performance of such a system is quite different from one containing only conventional generation. This is due to the chronological random nature of the solar radiation level and the dependencies

Roy Billinton; Bagen

2006-01-01

2

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

3

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

4

Hybrid Configuration of Darrieus and Savonius Rotors for Stand-alone Power Systems  

NASA Astrophysics Data System (ADS)

The suitable hybrid configuration of Darrieus lift-type and Savonius drag-type rotors for stand-alone wind turbine-generator systems is discussed using our dynamic simulation model. Two types of hybrid configurations are taken up: Type-A installs the Savonius rotor inside the Darrieus rotor and Type-B installs the Savonius rotor outside the Darrieus rotor. The computed results of the output characteristics and the dynamic behaviors of the system operated at the maximum power coefficient points show that Type-A, which has fine operating behavior to wind speed changes and can be compactly designed because of a shorter rotational shaft, is an effective way for self-controlled stand-alone small-scale systems.

Wakui, Tetsuya; Tanzawa, Yoshiaki; Hashizume, Takumi; Nagao, Toshio

5

Development of a microprocessor controller for stand-alone photovoltaic power systems  

NASA Technical Reports Server (NTRS)

A controller for stand-alone photovoltaic systems has been developed using a low power CMOS microprocessor. It performs battery state of charge estimation, array control, load management, instrumentation, automatic testing, and communications functions. Array control options are sequential subarray switching and maximum power control. A calculator keypad and LCD display provides manual control, fault diagnosis and digital multimeter functions. An RS-232 port provides data logging or remote control capability. A prototype 5 kW unit has been built and tested successfully. The controller is expected to be useful in village photovoltaic power systems, large solar water pumping installations, and other battery management applications.

Millner, A. R.; Kaufman, D. L.

1984-01-01

6

International market assessment of stand-alone photovoltaic power systems for cottage industry applications  

NASA Astrophysics Data System (ADS)

The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop.

Philippi, T. M.

1981-11-01

7

Stand-alone self-powered integrated microfluidic blood analysis system (SIMBAS).  

PubMed

We present a self-powered integrated microfluidic blood analysis system (SIMBAS) that does not require any external connections, tethers, or tubing to deliver and analyze a raw whole-blood sample. SIMBAS only requires the user to place a 5 ?L droplet of whole-blood at the inlet port of the device, whereupon the stand-alone SIMBAS performs on-chip removal of red and white cells, without external valving or pumping mechanisms, followed by analyte detection in platelet-containing plasma. Five complete biotin-streptavidin sample-to-answer assays are performed in 10 min; the limit of detection is 1.5 pM. Red and white blood cells are removed by trapping them in an integral trench structure. Simulations and experimental data show 99.9% to 100% blood cell retention in the passive structure. Powered by pre-evacuation of its PDMS substrate, SIMBAS' guiding design principle is the integration of the minimal number of components without sacrificing effectiveness in performing rapid complete bioassays, a critical step towards point-of-care molecular diagnostics. PMID:21152509

Dimov, Ivan K; Basabe-Desmonts, Lourdes; Garcia-Cordero, Jose L; Ross, Benjamin M; Park, Younggeun; Ricco, Antonio J; Lee, Luke P

2011-03-01

8

Stand-alone flat-plate photovoltaic power systems: System sizing and life-cycle costing methodology for Federal agencies  

NASA Technical Reports Server (NTRS)

A simple methodology to estimate photovoltaic system size and life-cycle costs in stand-alone applications is presented. It is designed to assist engineers at Government agencies in determining the feasibility of using small stand-alone photovoltaic systems to supply ac or dc power to the load. Photovoltaic system design considerations are presented as well as the equations for sizing the flat-plate array and the battery storage to meet the required load. Cost effectiveness of a candidate photovoltaic system is based on comparison with the life-cycle cost of alternative systems. Examples of alternative systems addressed are batteries, diesel generators, the utility grid, and other renewable energy systems.

Borden, C. S.; Volkmer, K.; Cochrane, E. H.; Lawson, A. C.

1984-01-01

9

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

10

Optimization of a stand-alone Solar PV-Wind-DG Hybrid System for Distributed Power Generation at Sagar Island  

NASA Astrophysics Data System (ADS)

An estimation of a stand-alone solar PV and wind hybrid system for distributed power generation has been made based on the resources available at Sagar island, a remote area distant to grid operation. Optimization and sensitivity analysis has been made to evaluate the feasibility and size of the power generation unit. A comparison of the different modes of hybrid system has been studied. It has been estimated that Solar PV-Wind-DG hybrid system provides lesser per unit electricity cost. Capital investment is observed to be lesser when the system run with Wind-DG compared to Solar PV-DG.

Roy, P. C.; Majumder, A.; Chakraborty, N.

2010-10-01

11

A high-performance stand-alone solar PV power system for LED lighting  

Microsoft Academic Search

The present study developed a high-performance solar PV power technology for the LED lighting of a solar home system. The nMPPO (near-Maximum-Power-Point-Operation) design is employed in system design to eliminate MPPT. A feedback control system using pulse width modulation (PWM) technique was developed for battery charging control which can increase the charging capacity by 78%. For high-efficiency lighting, the LED

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

2010-01-01

12

Control aspects of the Schuchuli Village stand-alone photovoltaic power system  

NASA Technical Reports Server (NTRS)

A photovoltaic power system in an Arizona Indian village was installed. The control subsystem of this photovoltaic power system was analyzed. The four major functions of the control subsystem are: (1) voltage regulation; (2) load management; (3) water pump control; and (4) system protection. The control subsystem functions flowcharts for the control subsystem operation, and a computer program that models the control subsystem are presented.

Groumpos, P. P.; Culler, J. E.; Delombard, R.

1984-01-01

13

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

14

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

15

Optimal sizing of battery storage for stand-alone hybrid (photo-voltaic + diesel) power systems  

NASA Astrophysics Data System (ADS)

An important element of hybrid photo- voltaic(PV) + diesel sytem is battery storage. Size of battery storage plays a role in optimum operation of the hybrid system. Emphasis needs to be placed on this issue. In this perspective, hourly solar radiation data, for the period 1986 93 recorded at Dhahran, Saudi Arabia, have been analyzed to investigate the optimum size of battery storage capacity for hybrid (PV + diesel) power systems. Various sizing configurations have been simulated. The monthly average daily values of solar global radiation range from 3.61 to 7.96kWh/m2. As a case study, hybrid systems considered in the present analysis consist of 225m2 PV array area (panels/modules) supplemented with battery storage unit and diesel backup generators (to meet the load requirements of a typical residential building with annual electrical energy demand of 35,200kWh). The monthly average energy generated from the aforementioned hybrid system for different scenarios has been presented. More importantly, the study explores the influence of variation of battery storage capacity on hybrid power generation. The results exhibit a trade-off between size of the storage capacity and diesel power to be generated to cope with annual load distribution. Concurrently, the energy to be generated from the diesel generator and the number of operational hours of the diesel system to meet the load demand have been also addressed.The study shows that for optimum operation of diesel system, storage capacity equivalent to 12 18h of maximum monthly average hourly demand need to be used. It has been found that in the absence of battery bank, ˜58% of the load needs to be provided by the diesel system. However, use of 12h of battery storage (autonomy) reduces diesel energy generation by ˜49% and the number of hours of operation of the diesel system get reduced by about ˜82%. The findings of this study can be employed as a tool for sizing of battery storage for PV/diesel systems for other regions having climates similar to the location considered in the study.

Shaahid, S. M.; Elhadidy, M. A.

2005-09-01

16

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

17

Review of the maximum power point tracking algorithms for stand-alone photovoltaic systems  

Microsoft Academic Search

A survey of the algorithms for seeking the maximum power point (MPP) is proposed. As has been shown, there are many ways of distinguishing and grouping methods that seek the MPP from a photovoltaic (PV) generator. However, in this article they are grouped as either direct or nondirect methods. The indirect methods (“quasi seeks”) have the particular feature that the

V. Salas; E. Olías; A. Barrado; A. Lázaro

2006-01-01

18

Power system analysis project Modeling and Sizing optimization of Stand-alone  

E-print Network

to explore a new way to do the site matching of wind turbine by introducing the design parameters: cut panels and wind turbine to meet the electricity demand. Several researches on optimization of sizing the new cost function of wind turbine accordingly. To make the system close to the building, small scale

Lavaei, Javad

19

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

20

Modular photovoltaic stand-alone systems: Phase 1  

NASA Technical Reports Server (NTRS)

A family of modular stand-alone power systems that covered the range in power level from 1 kw to 14 kw was developed. Products within this family were required to be easily adaptable to different environments and applications, and were to be both reliable and cost effective. Additionally, true commonality in hardware was to be exploited, and unnecessary recurrence of design and development costs were to be minimized; thus improving hardware availability. Assurance of compatibility with large production runs, was also an underlying program goal. A secondary objective was to compile, evaluate, and determine the economic and technical status of available, and potentially available, technology options associated with the balance of systems (BOS) for stand-along photovoltaic (PV) power systems. The secondary objective not only directly supported the primary but additionally contributed to the definition and implementation of the BOS cost reduction plan.

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

1983-01-01

21

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

22

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

23

An FPGA based stand-alone solar tracking system  

Microsoft Academic Search

This paper presents new design idea for stand-alone solar tracking system which is based on Field Programmable Gate Array (FPGA). The proposed idea of the design is based on astronomical equations to determine the position of the sun in the sky at any time of the day to calculate the azimuth angle and altitude angle for the two axis tracking

Fawzi M. Al-Naima; Bilal R. Al-Taee

2010-01-01

24

Comparison of battery charging algorithms for stand alone photovoltaic systems  

Microsoft Academic Search

The battery is the most common method of energy storage in stand alone solar systems; the most popular being the valve regulated lead acid battery (VRLA) due to its low cost and ease of availability. Photovoltaics are not an ideal source for charging batteries as their output is heavily dependent on weather conditions. Therefore, when batteries are used in photovoltaic

S. Armstrong; M. E. Glavin; W. G. Hurley

2008-01-01

25

Photovoltaic stand-alone modular systems, phase 2  

NASA Technical Reports Server (NTRS)

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.

1983-01-01

26

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

Microsoft Academic Search

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

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

2006-01-01

27

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

28

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

29

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

30

Performance of a stand-alone renewable energy system based on energy storage as hydrogen  

Microsoft Academic Search

Electrolytic hydrogen offers a promising alternative for long-term energy storage of renewable energy (RE). A stand-alone RE system based on energy storage as hydrogen has been developed and installed at the Hydrogen Research Institute, and successfully tested for autonomous operation with developed control system and power conditioning devices. The excess energy produced, with respect to the load requirement, has been

Kodjo Agbossou; Mohanlal Kolhe; Jean Hamelin; Tapan K. Bose

2004-01-01

31

Stand-alone and network capable pocket radiation detection system  

NASA Astrophysics Data System (ADS)

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 are 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 ?Ci 252Cf source at 5 m and from 1.4 mCi 252Cf source at 10 m 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 ?rem/h 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.

Aryaeinejad, R.; Spencer, D. F.

2009-03-01

32

Distributed Energy Management for Stand-Alone Photovoltaic System with Storages  

Microsoft Academic Search

\\u000a This paper presents a distributed energy management system (DEMS) for stand-alone photovoltaic(PV) system with storage devices.\\u000a Usually, batteries can be used as the storage device for PV system to compensate PV output power changed by irradiation and\\u000a temperature. Recently, Ultracapacitor has been adopted for the better dynamic characteristic of a whole system. The control\\u000a of these systems, called hybrid system,

Jae Hoon Cho; Dong Hwa-Kim

33

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

34

Pre-feasibility study of stand-alone hybrid energy systems for applications in Newfoundland  

Microsoft Academic Search

A potential solution for stand-alone power generation is to use a hybrid energy system in parallel with some hydrogen energy storage. In this paper, a pre-feasibility study of using hybrid energy systems with hydrogen as an energy carrier for applications in Newfoundland, Canada is explained. Various renewable and non-renewable energy sources, energy storage methods and their applicability in terms of

M. J. Khan; M. T. Iqbal

2005-01-01

35

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

Microsoft Academic Search

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

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

2007-01-01

36

COMPRESSED-AIR ENERGY STORAGE SYSTEMS FOR STAND-ALONE OFF-GRID PHOTOVOLTAIC MODULES  

E-print Network

COMPRESSED-AIR ENERGY STORAGE SYSTEMS FOR STAND-ALONE OFF-GRID PHOTOVOLTAIC MODULES Dominique storage system (SS- CAES) is proposed, which can be used in conjunction with off-grid stand-alone photo-voltaic production, is critically dependent on the availability of cost-effective, energy- storage technologies

Deymier, Pierre

37

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.

Benson, David K. (Golden, CO); Crandall, Richard S. (Boulder, CO); Deb, Satyendra K. (Boulder, CO); Stone, Jack L. (Lakewood, CO)

1995-01-01

38

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

39

Life cycle cost analysis of a stand-alone PV system in rural Kenya  

NASA Astrophysics Data System (ADS)

The purpose of this quantitative research study was to determine the economic feasibility of a stand-alone PV system to electrify a rural area in Kenya. The research conducted involved a comprehensive review of all the relevant literature associated with the study. Methodologies were extrapolated from this extensive literature to develop a model for the complete design and economic analysis of a stand-alone PV system. A women's center in rural Kenya was used as a worked example to demonstrate the workings of the model. The results suggest that electrifying the center using a stand-alone PV system is an economically viable option which is encouraging for the surrounding area. This model can be used as a business model to determine the economic feasibility of a stand-alone PV system in alternative sites in Kenya.

Daly, Emma

40

Status of DOE and AID stand-alone photovoltaic system field tests  

NASA Astrophysics Data System (ADS)

The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system projects sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, and PV-powered vaccine refrigerator systems in six countries. The AID project includes a large village power system, a farmhouse system and two water pumping-irrigation systems in Tunisia, a water pumping/grain grinding system in Upper Volta, five medical clinic systems in four countries, PV-powered vaccine refrigerator systems in 18 countries and a PV-powered remote earth station in Indonesia. This paper reviews these PV projects and summarizes significant findings to date.

Bifano, W. J.; Delombard, R.; Ratajczak, A. F.; Scudder, L. R.

41

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

42

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

43

Experimental optimization of the performance and reliability of stand-alone photovoltaic systems  

Microsoft Academic Search

Stand-alone photovoltaic systems are deceptively complex. Optimizing the performance and reliability of these systems requires a complete understanding of their behavior as a function of site-dependent environmental conditions. Individual component specifications provide useful design information. However, to fully understand the interactions between components, it is necessary to simultaneously characterize the performance of the system and its separate components under actual

David L. King; Thomas D. Hund; William E. Boyson; Jay A. Kratochvil

2002-01-01

44

Design of a stand alone system with renewable energy sources using trade off methods  

Microsoft Academic Search

The authors present an application of recent theoretical advances in multiobjective planning under uncertainty, in the design of a stand-alone system with renewable energy sources. The system under design consists of a wind energy plant, a solar plant, and an storage battery. Time series data on wind, insolation, and load for the site of interest are assumed to be available.

E. S. Gavanidous; A. G. Bakirtzis

1992-01-01

45

OPTIMIZATION WITH ENERGY MANAGEMENT OF PV BATTERY STAND-ALONE SYSTEMS OVER THE ENTIRE LIFE CYCLE  

E-print Network

, to reduce cycling costs (sizable in the case of lead-acid batteries [1]) can in turn be optimized accordingOPTIMIZATION WITH ENERGY MANAGEMENT OF PV BATTERY STAND-ALONE SYSTEMS OVER THE ENTIRE LIFE CYCLE of working on averaged time series data using much narrower time intervals (e.g. 1-hour series). Design

Paris-Sud XI, Université de

46

Implementation of a Stand-Alone Photovoltaic Lighting System with MPPT, Battery Charger and High Brightness LEDs  

Microsoft Academic Search

This paper presents a high-efficiency stand-alone photovoltaic (PV) lighting system which can provide functional illumination based on high-brightness light-emitting diodes (HBLEDs). HBLED with specific features of small size, long life and low power consumption will be choices of future light sources. In order to provide a steady-state operating environment for HBLEDs, a specially designed lighting power module is implemented. Maximum

Chih-Chiang Hua; Pi-Kuang Ku

2005-01-01

47

Energy management of hydrogen-based stand-alone renewable energy system by using boost and buck converters  

Microsoft Academic Search

Electrolytic hydrogen offers a promising alternative for long-term energy storage of renewable energy (RE). A stand-alone RE system based on energy storage in the form of hydrogen has been developed at the Hydrogen Research Institute and successfully tested for automatic operation with an in-house designed control system and power conditioning devices. In this system the excess energy with respect to

Kodjo Agbossou; Sousso Kélouwani; Adil Anouar; Mohanlal Kolhe

2004-01-01

48

Charactrization of a Li-ion battery based stand-alone a-Si photovoltaic system  

NASA Astrophysics Data System (ADS)

The number of photovoltaic (PV) system installations is increasing rapidly. As more people learn about this versatile and often cost-effective power option, this trend will accelerate. This document presents a recommended design for a battery based stand-alone photovoltaic system (BSPV). BSPV system has the ability to be applied in different areas, including warning signals, lighting, refrigeration, communication, residential water pumping, remote sensing, and cathodic protection. The presented calculation method gives a proper idea for a system sizing technique. Based on application load, different scenarios are possible for designing a BSPV system. In this study, a battery based stand-alone system was designed. The electricity generation part is three a-Si panels, which are connected in parallel, and for the storage part LFP (lithium iron phosphate) battery was used. The high power LFP battery packs are 40 cells each 8S5P (configured 8 series 5 parallel). Each individual pack weighs 0.5 kg and is 25.6 V. In order to evaluate the efficiency of a-Si panels with respect to the temperature and the solar irradiation, cities of Istanbul, Ankara and Adana in Turkey were selected. Temperature and solar irradiation were gathered from reliable sources and by using translation equations, current and voltage output of panels were calculated. As a result of these calculations, current and energy outputs were computed by considering an average efficient solar irradiation time value per day in Turkey. The calculated power values were inserted to a battery cycler system, and the behavior of high power LFP batteries in a time sequence of 7.2 h was evaluated. The charging and discharging cycles were obtained and their behavior was discussed. According to the results, Istanbul has the lowest number of peak month's energy, it followed by Ankara, and ultimately Adana has the highest number of peak months and energy storage. It was observed during the tests that values up to 4 A was discharged by battery packages in a full discharge cycle depending on application and required load.

Hamid Vishkasougheh, Mehdi; Tunaboylu, Bahadir

2014-11-01

49

Implementation of a stand-alone photovoltaic lighting system with MPPT battery charging and LED current control  

Microsoft Academic Search

This paper presents a efficient stand-alone battery photovoltaic (PV) lighting system which can provide functional illumination based on power light-emitting diodes (PLEDs). PLED with specific features of small size, long life and high-brightness light will be choices of future light sources. The PLEDs are feed using a lead acid battery that is charged with a PV panel. This paper presents

José António Barros Vieira; Alexandre Manuel Mota

2010-01-01

50

Optimal hydrogen production in a stand-alone renewable energy system  

Microsoft Academic Search

A stand-alone renewable wind-photovoltaic energy system can be used to meet the energy requirements of off-grid remote area applications. Such a system has been developed and successfully tested at the Hydrogen Research Institute (HRI). In the HRFs system the excess electrical energy with respect to load demand, is transformed and stored as hydrogen gas via an electrolyzer. The stored hydrogen

Kodjo Agbossou; M. L. Doumbia; A. Anouar

2005-01-01

51

A stand-alone ultrasonic ranging system for hydrological water stage measurements  

Microsoft Academic Search

A stand-alone ultrasonic ranging system (SAURS) was designed and applied in hydrological measurements of water levels. Ranging is carried out through air by an electrostatic ultrasonic transducer which is controlled by a microprocessor-based system. The data are collected in a 64-kbyte EPROM cassette. The problems associated with temperature correction were studied theoretically and experimentally. The advantages of remote water level

S. Ben-Yaakov; C. Golan; S. Kessler

1992-01-01

52

Space crew radiation exposure analysis system based on a commercial stand-alone CAD system  

NASA Technical Reports Server (NTRS)

Major improvements have recently been completed in the approach to spacecraft shielding analysis. A Computer-Aided Design (CAD)-based system has been developed for determining the shielding provided to any point within or external to the spacecraft. Shielding analysis is performed using a commercially available stand-alone CAD system and a customized ray-tracing subroutine contained within a standard engineering modeling software package. This improved shielding analysis technique has been used in several vehicle design projects such as a Mars transfer habitat, pressurized lunar rover, and the redesigned Space Station. Results of these analyses are provided to demonstrate the applicability and versatility of the system.

Appleby, Matthew H.; Golightly, Michael J.; Hardy, Alva C.

1992-01-01

53

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

54

Stand-alone digital data storage control system including user control interface  

NASA Technical Reports Server (NTRS)

A storage control system includes an apparatus and method for user control of a storage interface to operate a storage medium to store data obtained by a real-time data acquisition system. Digital data received in serial format from the data acquisition system is first converted to a parallel format and then provided to the storage interface. The operation of the storage interface is controlled in accordance with instructions based on user control input from a user. Also, a user status output is displayed in accordance with storage data obtained from the storage interface. By allowing the user to control and monitor the operation of the storage interface, a stand-alone, user-controllable data storage system is provided for storing the digital data obtained by a real-time data acquisition system.

Wright, Kenneth D. (Inventor); Gray, David L. (Inventor)

1994-01-01

55

System Simulation by Recursive Feedback: Coupling a Set of Stand-Alone Subsystem Simulations  

NASA Technical Reports Server (NTRS)

Conventional construction of digital dynamic system simulations often involves collecting differential equations that model each subsystem, arran g them to a standard form, and obtaining their numerical gin solution as a single coupled, total-system simultaneous set. Simulation by numerical coupling of independent stand-alone subsimulations is a fundamentally different approach that is attractive because, among other things, the architecture naturally facilitates high fidelity, broad scope, and discipline independence. Recursive feedback is defined and discussed as a candidate approach to multidiscipline dynamic system simulation by numerical coupling of self-contained, single-discipline subsystem simulations. A satellite motion example containing three subsystems (orbit dynamics, attitude dynamics, and aerodynamics) has been defined and constructed using this approach. Conventional solution methods are used in the subsystem simulations. Distributed and centralized implementations of coupling have been considered. Numerical results are evaluated by direct comparison with a standard total-system, simultaneous-solution approach.

Nixon, D. D.

2001-01-01

56

Neural networks-based control of active and reactive power of a stand-alone PEM fuel cell power plant  

NASA Astrophysics Data System (ADS)

This paper presents a neural networks (NN)-based active and reactive power controller of a stand-alone proton exchange membrane (PEM) fuel cell power plant (FCPP). The controller modifies the inverter modulation index and the phase angle of the ac output voltage to control the active and reactive power output from an FCPP to match the terminal load. The control actions are based on feedback signals from the terminal load, output voltage and hydrogen input. The validity of the controller is verified when the FCPP model is used in conjunction with the NN controller to predict the response of the power plant to: (a) computer-simulated step changes in the load active and reactive power demand, and (b) actual active and reactive load demand of a single family residence. The response curves indicate the load following characteristics of the model and the predicted changes in the analytical parameters highlighted by the analysis.

El-Sharkh, M. Y.; Rahman, A.; Alam, M. S.

57

An automated stand-alone in-field remote sensing system (SIRSS) for in-season crop monitoring  

Microsoft Academic Search

A stand-alone in field remote sensing system (SIRSS) with high spatial and temporal resolution was developed in this study. System control and image processing algorithms consisted of image acquisition control, camera parameter control, crop canopy reflectance calibration, image rectification, image background segmentation and vegetation indices map generation were developed and embedded in the SIRSS. The SIRSS is able to automatically

Haitao Xiang; Lei Tian

2011-01-01

58

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

59

The Stand-Alone Microprocessor System: A Valuable Tool in College Admissions and Recruitment.  

ERIC Educational Resources Information Center

The stand-alone microprocessor is seen as one innovative tool that can be used both in the organizational management of decline and in meeting specific organizational needs such as those of the admissions director and staff. The term "microprocessor" is defined. (MLW)

Garrett, Larry Neal

1983-01-01

60

A stand-alone demography and landscape structure module for Earth system models  

NASA Astrophysics Data System (ADS)

We propose and demonstrate a new approach for the simulation of woody ecosystem stand dynamics, demography and disturbance-mediated heterogeneity suitable for continental to global applications and designed for coupling to the terrestrial ecosystem component of any earth system model (Haverd et al., 2013). The approach is encoded in a model called Populations-Order-Physiology (POP). We demonstrate the behaviour and performance of POP coupled to the Community Atmosphere Biosphere Land Exchange model (CABLE) for two contrasting applications: (i) to the Northern Australian Tropical Transect, featuring gradients in savanna vegetation cover, rainfall and fire disturbance and (ii) to a set of globally distributed forest locations coinciding with observations of forest biomass allometry. Along the Northern Australian Tropical Transect, CABLE-POP is able to simultaneously reproduce observation-based estimates of key functional and structural variables, namely gross primary production, tree foliage projective cover, basal area and maximum tree height. This application particularly demonstrates the ability of POP to quantify the contributions of drought and fire to tree mortality. Drought is manifested as an increase in mortality due to a decline in growth efficiency, while fires are treated as partial disturbance events, with tree mortality depending on tree size and fire intensity. In the application to global forests, POP is integrated with global forest data by calibrating it against paired observations of stem biomass and number density. The calibrated POP model is then coupled with CABLE and the coupled model is evaluated against leaf-stem allometry observations from forest stands ranging in age from 20 to 400 years. Results indicate that, in contrast to simulations from many global land surface models (Wolf et al., 2011), simulated biomass pools conform well with observed allometry. We conclude that POP, which can readily be coupled to the terrestrial carbon cycle component of any LSM, represents a significant advance in our ability to use in-situ and remotely sensed observations of biomass and individual level parameters (e.g. crown-size, tree-height, stem diameter) as constraints on the terrestrial carbon cycle. Haverd, V., B. Smith, G. Cook, P. Briggs, L. Nieradzik, S. Roxburgh, A. Liedloff, C. Meyer, and J. G. Canadell, A stand-alone tree demography and landscape structure module for Earth system models, submitted to Geophys. Res. Let., 2013 Wolf, A., P. Ciais, V. Bellassen, N. Delbart, C.B. Field, and J.A. Berry, Forest biomass allometry in global land surface models, Global Biogeochem. Cycles, 25, GB3015, doi:10.1029/2010GB003917, 2011

Nieradzik, L. P.; Haverd, V.; Smith, B.; Cook, G. D.; Briggs, P.; Roxburgh, S.; Liedloff, A.; Meyer, C.; Canadell, J.

2013-12-01

61

Design and Implementation of a Novel High-performance Stand-alone Photovoltaic LED Lighting System  

Microsoft Academic Search

This paper presents a novel high-performance standalone photovoltaic (PV) lighting system which can provide functional illumination based on high power White LEDs. An improved incremental conductance Maximum Power Point Tracking (MPPT) method is proposed in PV system to maximize the photovoltaic array output power, irrespective of the temperature and irradiation conditions and of the load electrical characteristics. A novel strategy

Ye Ai; Tingzhang Liu; Shisong Wang

2010-01-01

62

Possible use of vanadium redox-flow batteries for energy storage in small grids and stand-alone photovoltaic systems  

NASA Astrophysics Data System (ADS)

The all-vanadium redox-flow battery is a promising candidate for load leveling and seasonal energy storage in small grids and stand-alone photovoltaic systems. The reversible cell voltage of 1.3 to 1.4 V in the charged state allows the use of inexpensive active and structural materials. In this work, studies on the performance of inexpensive active materials for use in vanadium redox-flow batteries are reported. Additionally, a cost analysis for a load leveling and a seasonal energy storage system is given based on a flow battery technology well established in Zn-flow batteries.

Joerissen, Ludwig; Garche, Juergen; Fabjan, Ch.; Tomazic, G.

63

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

64

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

E-print Network

. This article proposes a method to optimize the design of a small fixed-voltage wind energy conversion system optimization. Nomenclature Pt Wind turbine mechanical power (W) A Wind turbine blade sweeping surface (m²) R Wind turbine blade radius (m) Cp Wind turbine power coefficient (­) Tip-speed ratio (­) Wind turbine

Paris-Sud XI, Université de

65

Honeywell Parallon Stand-alone Tests Honeywell Stand-alone Tests  

E-print Network

: Ramp Down Tests ­ Power and DC Bus Voltage ­ kW and kVAR Steps #12;Honeywell Stand-alone Tests 5 Figure E-1: Ramp Down Tests ­ Power and Shaft Speed ­ kW and kVAR Steps #12;Honeywell Stand-alone Tests 5 Down Tests ­ Power and Turbine Exit Temperature ­ kW and kVAR Steps #12;Honeywell Stand-alone Tests 5

66

A compact seven switches topology and reduced DC-link capacitor size for single-phase stand-alone PV system with hybrid energy storages  

Microsoft Academic Search

Single-phase stand-alone PV system is suitable for household applications in remote area. Hybrid battery\\/ultra- capacitor energy storage can reduce charge and discharge cycles and avoid deep discharges of battery. This paper proposes a compact seven switches structure for stand-alone PV system, which otherwise needs nine switches configuration, inclusive of one switch for boost converter, four switches for single-phase inverter and

Xiong Liu; Peng Wang; Poh Chiang Loh; Frede Blaabjerg; Feng Gao

2011-01-01

67

The effects of controls and controllable and storage loads on the performance of stand-alone photovoltaic systems  

NASA Technical Reports Server (NTRS)

Stand-alone photovoltaic systems have been modeled and analyzed from sunlight in to consumer product out. By including the consumer product in the analysis, concepts such as 'product storage' (a storage tank for water or cold-plates for refrigeration) and loads controllable by the system controller have been added to the system analysis. From a controls analysis viewpoint, this adds state variables to the system. The result is that the system controller can make operating control decisions on the energy flow between these various system elements to optimize system performance and reduce system cost. The effects on system performance of various control schemes employing these concepts are presented. Analysis of water pumping and/or refrigeration systems show possible performance improvements of greater than 15% with the addition of controllable loads with product storage.

Cull, R. C.; Eltimsahy, A. H.

1981-01-01

68

Supervisor control for a stand-alone hybrid generation system using wind and photovoltaic energy  

Microsoft Academic Search

A comprehensive supervisor control for a hybrid system that comprises wind and photovoltaic generation subsystems, a battery bank, and an ac load is developed in this paper. The objectives of the supervisor control are, primarily, to satisfy the load power demand and, second, to maintain the state of charge of the battery bank to prevent blackout and to extend the

Fernando Valenciaga; Paul F. Puleston

2005-01-01

69

Stand-alone development system using a KIM-1 microcomputer module  

NASA Technical Reports Server (NTRS)

A small microprocessor-based system designed to: contain all or most of the interface hardware, designed to be easy to access and modify the hardware, to be capable of being strapped to the seat of a small general aviation aircraft, and to be independent of the aircraft power system is described. The system is used to develop a low cost Loran C sensor processor, but is designed such that the Loran interface boards may be removed and other hardware interfaces inserted into the same connectors. This flexibility is achieved through memory-mapping techniques into the microprocessor.

Nickum, J. D.

1978-01-01

70

Robust optimal sizing of an hybrid energy stand-alone system  

E-print Network

Mar 24, 2014 ... tem composed of wind turbines, solar photovoltaic panels and batteries. To ... that show the efficiency of the proposed constraint generation algorithm. ... ering investment costs and power production criteria; a mixed-integer ...

2014-03-24

71

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

72

NASA preprototype redox storage system for a photovoltaic stand-alone application  

NASA Technical Reports Server (NTRS)

A 1 kW preprototype redox storage system underwent characterization tests and was operated as the storage device for a 5 kW (peak) photovoltaic array. The system is described and performance data are presented. Loss mechanisms are discussed and simple design changes leading to significant increases in efficiency are suggested. The effects on system performance of nonequilibrium between the predominant species of complexed chromic ion in the negative electrode reactant solution are indicated.

Hagedorn, N. H.

1981-01-01

73

Novel Technique of Sizing the Stand-Alone Photovoltaic Systems Using the Radial Basis Function Neural Networks: Application in Isolated Sites  

E-print Network

to the users of stand-alone PV systems to determine the number of solar panel modules and storage batteries necessary to satisfy a given consumption. The advantage of this model is to estimate of the sizing PV system in any site in Algeria particularly...

Mellit, A.; Benghanme, M.; Arab, A. H.; Guessoum, A.

2004-01-01

74

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. PMID:23223100

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

2013-01-01

75

Honeywell Parallon Delta Measurement Stand-alone Tests Honeywell Stand-alone Delta Tests  

E-print Network

Appendix F Honeywell Parallon Delta Measurement Stand-alone Tests 6/20/2001 #12;Honeywell Stand-alone Delta Tests 6/20/2001 -10,000 0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 80,000 0 50 100 150 200 (VAR) Engine Speed Figure F-1: Ramp Tests ­ Power and Shaft Speed ­ Delta Measurements #12;Honeywell

76

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

77

Comparison between solar utilization of a closed microalgae-based bio-loop and that of a stand-alone photovoltaic system.  

PubMed

This study compared the solar energy utilization of a closed microalgae-based bio-loop for energy efficient production of biogas with fertilizer recovery against that of a stand-alone photovoltaic (PV) system. The comparison was made from the perspective of broad life cycle assessment, simultaneously taking exergy to be the functional unit. The results indicated that the bio-loop was more environmentally competitive than an equivalent stand-alone PV system, but had higher economic cost due to high energy consumption during the operational phase. To fix the problem, a patented, interior pressurization scheduling method was used to operate the bio-loop, with microalgae and aerobic bacterial placed together in the same reactor. As a result, the overall environmental impact and total investment were respectively reduced by more than 75% and 84%, a vast improvement on the bio-loop. PMID:25465781

Jin, Qiang; Chen, Lei; Li, Aimin; Liu, Fuqiang; Long, Chao; Shan, Aidang; Borthwick, Alistair G L

2014-11-01

78

Evaluation of stand-alone inverters for remote applications  

NASA Astrophysics Data System (ADS)

A stand-alone or autonomous system that supplies ac electric power to loads in remote applications is a mini-utility. It requires all the basic elements of a large system. These basic elements are an energy source, a storage medium, and a power conditioner (inverter) with built-in or external control and distribution capabilities. The source for an autonomous system will probably be one of the renewable sources of energy such as wind or photovoltaics. The electrical storage will be a battery bank. The inverter, with the variable energy source and the energy storage sized for the autonomy of the system, must be capable of converting the energy and supplying controlled ac power to the loads on demand and in a safe, efficient, reliable, and compatible manner. This paper describes the evaluation of several small (typically 1-kW) stand-alone power conditioners. The purpose of these evaluations was to determine the dc input and ac output characteristics of the power conditioners, the control algorithms, and the compatibility and interactions of the power conditioners with the complex loads most likely to be used with the stand-alone or autonomous systems.

Bower, W.

79

Breaking through market barriers with an improved sizing method: Case study of a stand-alone PV system in the northern Sudan  

SciTech Connect

According to the sizing methodology used here, a stand-alone photovoltaic irrigation water-pumping system for installation in northern Sudan would cost less than anticipated by other sizing methods. This method makes use of the concept of system reliability or availability without the attendant computational complexity or unwieldiness associated with many other sizing methodologies presented in the literature. Thus, two barriers to the use of photovoltaic systems for electricity generation are addressed by an improved method of estimation. One is the commonly cited claim that PV systems are too costly. The other is that the computer-aided design methods for predicting performance are too complex or difficult to use. This makes one wonder if other objections to the use of renewable-energy technologies could be overcome through improving methods of specifying systems. 19 refs., 4 figs., 1 tab.

Lewis, G. (Memphis State Univ., TN (USA))

1990-12-01

80

Standing alone with prosodic help*  

PubMed Central

Two partially independent issues are addressed in two auditory rating studies: under what circumstances is a sub-string of a sentence identified as a stand-alone sentence, and under what circumstances do globally ill-formed but ‘locally coherent’ analyses (Tabor, Galantucci, & Richardson., 2004) emerge? A new type of locally coherent structure is established in Experiment 1, where a that-less complement clause is at least temporarily analyzed as a stand-alone sentence when it corresponds to a prosodic phrase. In Experiment 2, reduced relative clause structures like those in Tabor et al. were investigated. As in Experiment 1, the root sentence (mis-)analyses emerged most frequently when the locally coherent clause corresponded to a prosodic phrase. However, a substantial number of locally coherent analyses emerged even without prosodic help, especially in examples with for-datives (which do not grammatically permit a reduced relative clause structure for some speakers). Overall, the results suggest that prosodic grouping of constituents encourages analysis of a sub-string as a root sentence, and raise the question of whether all local coherence structures involve analysis of an utterance-final sub-string as a root sentence. PMID:24729648

Frazier, Lyn; Clifton, Charles; Carlson, Katy; Harris, Jesse A.

2013-01-01

81

A new technique based on Artificial Bee Colony Algorithm for optimal sizing of stand-alone photovoltaic system  

PubMed Central

One of the most recent optimization techniques applied to the optimal design of photovoltaic system to supply an isolated load demand is the Artificial Bee Colony Algorithm (ABC). The proposed methodology is applied to optimize the cost of the PV system including photovoltaic, a battery bank, a battery charger controller, and inverter. Two objective functions are proposed: the first one is the PV module output power which is to be maximized and the second one is the life cycle cost (LCC) which is to be minimized. The analysis is performed based on measured solar radiation and ambient temperature measured at Helwan city, Egypt. A comparison between ABC algorithm and Genetic Algorithm (GA) optimal results is done. Another location is selected which is Zagazig city to check the validity of ABC algorithm in any location. The ABC is more optimal than GA. The results encouraged the use of the PV systems to electrify the rural sites of Egypt.

Mohamed, Ahmed F.; Elarini, Mahdi M.; Othman, Ahmed M.

2013-01-01

82

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

83

DOE and AID stand-alone photovoltaic activities  

NASA Astrophysics Data System (ADS)

The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system activities sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, PV-powered medical refrigerators in six countries, PV system microprocessor control development activities and PV-hybrid system assessments. The AID project includes a large village system in Tunisia, a water pumping/grain grinding project in Upper Volta, five medical clinics in four countries, PV-powered remote earth station application. These PV activities and summarizes significant findings to data are reviewed.

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

84

DOE and AID stand-alone photovoltaic activities  

NASA Technical Reports Server (NTRS)

The NASA Lewis Research Center (LeRC) is managing stand-alone photovoltaic (PV) system activities sponsored by the U.S. Department of Energy (DOE) and the U.S. Agency for International Development (AID). The DOE project includes village PV power demonstration projects in Gabon (four sites) and the Marshall Islands, PV-powered medical refrigerators in six countries, PV system microprocessor control development activities and PV-hybrid system assessments. The AID project includes a large village system in Tunisia, a water pumping/grain grinding project in Upper Volta, five medical clinics in four countries, PV-powered remote earth station application. These PV activities and summarizes significant findings to data are reviewed.

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

1983-01-01

85

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

86

A stand-alone peristaltic micropump based on piezoelectric actuation  

Microsoft Academic Search

Despite significant efforts to develop micropumps, cumbersome driving equipment means that the design of portable micropumps\\u000a remains a challenge. This study presents a stand-alone micropump system, which includes a peristaltic micropump based on piezoelectric\\u000a actuation and a driving circuit. This battery-based driving circuit comprises a 12 V battery, an ATmega 8535 microprocessor,\\u000a a 12 V-to-180 V DC to DC converter using transformerless technology,

Ling-Sheng Jang; Yuan-Jie Li; Sung-Ju Lin; Yi-Chu Hsu; Wu-Sung Yao; Mi-Ching Tsai; Ching-Cheng Hou

2007-01-01

87

Dynamic modeling, design and simulation of a combined PEM fuel cell and ultra-capacitor 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 can not store significant amount of energy. The combined use of FC and UC

M. Uzunoglu; M. S. Alam

2006-01-01

88

A stand-alone peristaltic micropump based on piezoelectric actuation.  

PubMed

Despite significant efforts to develop micropumps, cumbersome driving equipment means that the design of portable micropumps remains a challenge. This study presents a stand-alone micropump system, which includes a peristaltic micropump based on piezoelectric actuation and a driving circuit. This battery-based driving circuit comprises a 12 V battery, an ATmega 8535 microprocessor, a 12 V-to-180 V DC to DC converter using transformerless technology, three differential amplifiers, an IC 7805, a phase controller, an A/D converter, a keyboard and an LCD module. The system can produce step-function signals with voltages of up to 228 V(pp) and frequencies ranging from 10 Hz to 100 kHz, as the inputs for the pump. It is portable and programmable with the package size of 22 x 12.8 x 9 cm. Additionally, this proposed system is used to design the driving signals of the pump which are 3-, 4, and 6-phase actuation sequences. This work performs the circuit testing and fluid pumping, and demonstrates the effects of actuation sequences on pump performance in terms of the dynamic behavior of the diaphragm, flow rates, back pressure and power consumption of the system. The experimental results show that the pump excited by the 6-phase sequence results in better performance compared with the 3- and 4-phase sequences, and produces a maximum flow rate of 36.8 microl/min and a maximum back pressure of 520 Pa with deionized water at 100 V (pp) and 700 Hz. PMID:17160705

Jang, Ling-Sheng; Li, Yuan-Jie; Lin, Sung-Ju; Hsu, Yi-Chu; Yao, Wu-Sung; Tsai, Mi-Ching; Hou, Ching-Cheng

2007-04-01

89

Design and implementation of a machine vision based but low cost stand alone system for real time counterfeit Bangladeshi bank notes detection  

Microsoft Academic Search

This paper presents the design of a machine vision based system for real time detection of the counterfeit Bangladeshi bank notes. The proposed system works with the denominations of five hundred and one hundred taka. This system relies on a specific feature of the both five hundred and one hundred taka. The relied feature is not possible to replicate for

K. Yoshida; M. Kamruzzaman; F. A. Jewel; R. F. Sajal

2007-01-01

90

CAD-based stand-alone spacecraft radiation exposure analysis system: An application of the early man-tended Space Station  

NASA Technical Reports Server (NTRS)

Major improvements have been completed in the approach to analyses and simulation of spacecraft radiation shielding and exposure. A computer-aided design (CAD)-based system has been developed for determining the amount of shielding provided by a spacecraft and simulating transmission of an incident radiation environment to any point within or external to the vehicle. Shielding analysis is performed using a customized ray-tracing subroutine contained within a standard engineering modeling software package. This improved shielding analysis technique has been used in several vehicle design programs such as a Mars transfer habitat, pressurized lunar rover, and the redesigned international Space Station. Results of analysis performed for the Space Station astronaut exposure assessment are provided to demonastrate the applicability and versatility of the system.

Appleby, M. H.; Golightly, M. J.; Hardy, A. C.

1993-01-01

91

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

92

Collaborative Eclipse Plug-in Integration Architecture for stand alone  

E-print Network

Collaborative Eclipse Plug-in Integration Architecture for stand alone programs (agents) A project Report Summary By Shajil K Kalathil (04/29/2005) #12;Table of Contents 1. Eclipse Platform Overview................................................................ 3 2. Eclipse Cross Section

Jones, Edward

93

21 CFR 801.50 - Labeling requirements for stand-alone software.  

Code of Federal Regulations, 2014 CFR

...false Labeling requirements for stand-alone software. 801.50 Section 801.50 Food and Drugs...50 Labeling requirements for stand-alone software. (a) Stand-alone software that is not distributed in packaged...

2014-04-01

94

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 teachers…

Wang, Yu-Mei

2006-01-01

95

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

96

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

97

Fuzzy logic control of fuel cell for stand-alone and grid connection  

NASA Astrophysics Data System (ADS)

Fuel cells have become one of the major areas of research in the academia and the industry with the numerous advantages they provide over the batteries and especially over the other small-scale sources of electricity including the photovoltaic and solar cells. Fuel cells generate electricity from hydrogen by a chemical process and are environmentally safe and efficient. Fuel cells have numerous stand-alone and grid-connected applications. The aim of the paper is to achieve the control of the fuel cell for stand-alone and grid connection. This is achieved by designing a suitable power conditioning unit. The power conditioning unit is needed for processing of the raw power output of the fuel cell in order to make it usable. The power conditioning unit might have only dc/dc converter or the two stages of dc/dc converter and dc/ac inverter. For the stand-alone part, the concentration is on the controlled direct current (dc) power, thus, only a boost converter (dc/dc) stage is used. For the grid interface of the fuel cell, controlled alternating current (ac) power is needed at the interface point of the fuel cell and the utility grid; thus, both stages, boost converter as well as the inverter (dc/ac), are needed. A power conditioning unit is designed for the solid oxide fuel cell, which can be used for other fuel cells with converter and the inverter of different ratings, but the control strategy will remain the same. The fuzzy logic control strategy is used for designing the controllers for both the stages.

Sakhare, Abhishek; Davari, Asad; Feliachi, Ali

98

SPEED: Stand-alone programmable ethernet enabled devices  

Microsoft Academic Search

In this paper we present the design and synthesis of Standalone Programmable Ethernet Enabled Devices (SPEED) as a low cost and power consumption embedded system, which also include an Electrical Erasable Programmable Read Only Memory controller for configurable address assignments.The main function of SPEED is to eliminate the operating system processing of network protocol stack running by personal computer processor

Omar S. Elkeelany; Ghulam Chaudhry

2004-01-01

99

Market assessment of photovoltaic power systems for agricultural applications in Nigeria  

NASA Technical Reports Server (NTRS)

The market potential for stand-alone photovoltaic systems in agriculture was studied. Information is presented on technical and economically feasible applications, and assessments of the business, government and financial climate for photovoltaic sales. It is concluded that the market for stand-alone systems will be large because of the availability of captial and the high premium placed on high reliability, low maintenance power systems. Various specific applications are described, mostly related to agriculture.

Staples, D.; Steingass, H.; Nolfi, J.

1981-01-01

100

A rule-based fuzzy logic controller for a PWM inverter in a stand alone wind energy conversion scheme  

Microsoft Academic Search

The paper presents a rule-based fuzzy logic controller to control the output power of a pulse width modulated (PWM) inverter used in a stand-alone wind energy conversion scheme (SAWECS). The self-excited induction generator used in SAWECS has the inherent problem of fluctuations in the magnitude and frequency of its terminal voltage with changes in wind velocity and load. To overcome

Rohin M. Hilloowala; Adel M. Sharaf

1996-01-01

101

45 CFR 156.150 - Application to stand-alone dental plans inside the Exchange.  

Code of Federal Regulations, 2014 CFR

...for two or more covered children. (b) Calculation of AV. A stand-alone dental plan: (1) May not use the AV calculator in § 156.135 of this subpart; (2) Must demonstrate that the stand-alone dental plan offers the pediatric dental...

2014-10-01

102

45 CFR 156.150 - Application to stand-alone dental plans inside the Exchange.  

Code of Federal Regulations, 2013 CFR

...regard to out-of-network services. (b) Calculation of AV. A stand-alone dental plan: (1) May not use the AV calculator in § 156.135 of this subpart; (2) Must demonstrate that the stand-alone dental plan offers the pediatric dental...

2013-10-01

103

University of Essex Rules of Assessment for stand-alone Postgraduate Diplomas Page 1 of 4  

E-print Network

University of Essex Rules of Assessment for stand-alone Postgraduate Diplomas Page 1 of 4 UNIVERSITY OF ESSEX GRADUATE SCHOOL RULES OF ASSESSMENT FOR POSTGRADUATE DIPLOMAS 2011/12 (where offered as a stand-alone award) 1 PREAMBLE a) These rules apply to full-time (9 months) postgraduate diploma courses

Codling, Edward A.

104

University of Essex Rules of Assessment for stand-alone Postgraduate Diplomas UNIVERSITY OF ESSEX  

E-print Network

University of Essex Rules of Assessment for stand-alone Postgraduate Diplomas UNIVERSITY OF ESSEX GRADUATE SCHOOL RULES OF ASSESSMENT FOR POSTGRADUATE DIPLOMAS 2009/10 (where offered as a stand-alone award) 1. PREAMBLE These rules apply to full-time (9 months) postgraduate diploma courses. The rules should

105

The vanadium redox battery - an energy reservoir for stand-alone ITS applications along motor and expressways  

Microsoft Academic Search

This paper presents a new technology\\/system to supply stand-alone ITS applications along motor- and expressways with electrical energy. The constantly increasing requirement for general mobility, while at the same time ensuring personal safety, requires a broad-based information system, including also the entire network of traffic routes. Focusing on traffic routes, traffic management and information systems are under consideration all over

Martha Schreiber; Adam H. Whitehead; Martin Harrer; René Moser

2005-01-01

106

Study of Stand-Alone Microgrid under Condition of Faults on Distribution Line  

NASA Astrophysics Data System (ADS)

The behavior of stand-alone microgrid is analyzed under the condition of faults on distribution feeders. During fault since battery is not able to maintain dc-link voltage within limit, the resistive dump load control is presented to do so. An inverter control is proposed to maintain balanced voltages at PCC under the unbalanced load condition and to reduce voltage unbalance factor (VUF) at load points. The proposed inverter control also has facility to protect itself from high fault current. Existing maximum power point tracker (MPPT) algorithm is modified to limit the speed of generator during fault. Extensive simulation results using MATLAB/SIMULINK established that the performance of the controllers is quite satisfactory under different fault conditions as well as unbalanced load conditions.

Malla, S. G.; Bhende, C. N.

2014-10-01

107

Real-time GPS seismology with a stand-alone receiver: A preliminary feasibility demonstration  

NASA Astrophysics Data System (ADS)

We show the feasibility of a real-time estimation of waveforms and coseismic displacements, within a few centimeters in accuracy, with a stand-alone dual-frequency Global Positioning System (GPS) receiver using a so-called "variometric" approach. The approach is based on time single-differences of carrier phase observations collected at a high-rate (1 Hz or more) using a stand-alone receiver, and on standard GPS broadcast products (orbits and clocks), which are ancillary information routinely available in real time. In the approach, first, the time series of epoch-by-epoch displacements are estimated. Then, provided that the collected observations are continuous, they can be summed over the interval (limited to a few minutes) over which an earthquake occurs. Since epoch-by-epoch displacements divided by the interval between consecutive epochs are essentially equal to the epoch-by-epoch velocities, this is equivalent to saying that we are using the GPS receiver as a velocimeter. Estimation biases, due to the possible mismodeling of various intervening effects (such as multipath, residual clock errors, orbit errors, and atmospheric errors), accumulate over time and display their signature as a trend in coseismic displacements. The trend can be considered linear and easily removed, at least for short intervals. Since the proposed approach (named VADASE (Variometric Approach for Displacements Analysis Stand-alone Engine)) does not require either additional technological complexity or a centralized data analysis, in principle it can be embedded into GPS receiver firmware, thereby providing a significant contribution to tsunami warning and other hazard assessment systems. After a preliminary test using a simulated example, the effectiveness of this approach was proven using real data. We analyzed the 1 Hz GPS data recorded by the International Global Navigation Satellite Systems Service station BREW during the Denali Fault, Alaska, earthquake (Mw 7.9, 3 November, 2002, 22:12:41 UTC), as well as the 5 Hz data collected by some of the stations of the University NAVSTAR Consortium-Plate Boundary Observatory network and the California Real Time Network during the Baja California, Mexico, earthquake (Mw 7.2, 4 April, 2010, 22:40:42 UTC). Comparisons of the results obtained using VADASE, as well as other already well-established approaches, displayed agreement to within a few centimeters.

Colosimo, G.; Crespi, M.; Mazzoni, A.

2011-11-01

108

Development of stand-alone germanium solar cells for application in space using spin-on diffusants  

Microsoft Academic Search

The development of stand-alone germanium solar cells is essential for application of this type of cell in highly efficient mechanically stacked solar cells and in Thermo Photo-Voltaic (TPV) systems. Up to now the highest efficiency reported for this type of cell is 6.4 percent (AM0). Simulations show that in order to obtain high efficiencies it is essential to create a

N. E. Posthuma; G. Flamand; J. Poortmans

2003-01-01

109

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

Code of Federal Regulations, 2013 CFR

...considered under the stand-alone cost methodology. 1109.4 Section 1109.4 Transportation...considered under the stand-alone cost methodology. (a) Mandatory use of mediation...case involving the stand-alone cost methodology must engage in non-binding...

2013-10-01

110

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

Code of Federal Regulations, 2012 CFR

...considered under the stand-alone cost methodology. 1109.4 Section 1109.4 Transportation...considered under the stand-alone cost methodology. (a) A shipper seeking rate relief...case involving the stand-alone cost methodology must engage in non-binding...

2012-10-01

111

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

112

Stand-alone and hybrid positioning using asynchronous pseudolites.  

PubMed

global navigation satellite system (GNSS) receivers are usually unable to achieve satisfactory performance in difficult environments, such as open-pit mines, urban canyons and indoors. Pseudolites have the potential to extend GNSS usage and significantly improve receiver performance in such environments by providing additional navigation signals. This also applies to asynchronous pseudolite systems, where different pseudolites operate in an independent way. Asynchronous pseudolite systems require, however, dedicated strategies in order to properly integrate GNSS and pseudolite measurements. In this paper, several asynchronous pseudolite/GNSS integration strategies are considered: loosely- and tightly-coupled approaches are developed and combined with pseudolite proximity and receiver signal strength (RSS)-based positioning. The performance of the approaches proposed has been tested in different scenarios, including static and kinematic conditions. The tests performed demonstrate that the methods developed are effective techniques for integrating heterogeneous measurements from different sources, such as asynchronous pseudolites and GNSS. PMID:25609041

Gioia, Ciro; Borio, Daniele

2014-01-01

113

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

114

EVALUATION AND USE OF STAND-ALONE COMMERCIAL PHOTOLYTIC CONVERTERS FOR NO2 TO NO CONVERSION  

EPA Science Inventory

Two types of stand-alone commercial photolytic converters of NO2 to NO are now available for use with NO, O3 chemiluminescence monitors for the measurement of NO2. Both units have been tested for interferences resulting from photolysis of HONO or from decomposition of PAN. On...

115

A Layerwise Shell Stiffener and Stand-Alone Curved Beam Element  

E-print Network

1 A Layerwise Shell Stiffener and Stand-Alone Curved Beam Element SAMUEL KINDE KASSEGNE* and J. N-dimensional stiffener element for laminated composite shells and plates is developed based on the Layerwise Theory of Reddy for composite laminates. The element has a displacement field compatible with that of a layerwise

Kassegne, Samuel Kinde

116

University of Essex Rules of Assessment for stand-alone Graduate Diplomas Page 1 of 4  

E-print Network

University of Essex Rules of Assessment for stand-alone Graduate Diplomas Page 1 of 4 UNIVERSITY OF ESSEX GRADUATE SCHOOL RULES OF ASSESSMENT FOR GRADUATE DIPLOMAS 2011/12 (where offered as a stand. ________________________________________________________________________________________ 2 PASS MARK a) The pass mark for all modules of the Graduate Diploma is 40. b) For the purposes

Codling, Edward A.

117

Stand Alone Pressure Measurement Device (SAPMD) for the space shuttle Orbiter, part 1  

NASA Technical Reports Server (NTRS)

The specifications for the Stand Alone Pressure Measurement Device (SAPMD) are as follows: the SAPMD shall measure ambient pressure at the surface of the Orbiter TPS in the range of 0 to 15 pounds per square inch absolute (PSIA). Measurement will begin at solid rocket booster (SRB) ignition as sensed by appropriate vibration sensing elements in the SAPMD. Pressure and corresponding real-time data are to be recorded every one tenth second for 140 seconds and at the end of the recording period, the operation will be discontinued with the data preserved for interrogation subsequent to Orbiter re-entry and landing. The type and size of the battery shall be such as to allow the vibration sensing elements and a real-time clock to be initialized a minimum of 30 day prior to launch and still provide power as necessary to perform the 140 second data recording period after SRB ignition. Battery installation shall be in such a manner as to allow battery replacement without removing the SAPMD from its position or removing more than one TPS tile. The SAPMD must be mounted in specific locations under tile of the TPS. To accommodate such mounting, the absolute maximum physical dimensions much not exceed 6.0 inches in length, 1.5 inches in width, and 0.4 inches in height, and the device shall be of such configuration that it can be bonded to the Orbiter skin at the joint line of two TPS tiles with the pressure sensing port at the surface of the tile. The SAPMD must remain operational in the temperature range of -40 to +85 C and survive storage temperature of -55 to +125 C. The pressure port must withstand 934 C without causing damage to the TPS during entry and must remain functional at 262 C during ascent. The accuracy of the pressure measurement must be plus or minus one-half PSIA over a temperature range of 0 to +36 C. All the specifications were met and verified by prototype testing and documented in the enclosed test data. Four flight-qualified models were fabricated and of these, two were delivered and successfully flown in the cargo bay of STS-26.

Tomlinson, Bill

1989-01-01

118

A stand-alone alphanumeric CRT teleprocessor unit for a Hewlett-Packard 2114B minicomputer  

E-print Network

. T. yne (Chairman Conmi ttee) ;, ' . Jones (Head 4f Department) . Druce ( ember) ~4. 0 ooc (Member) August 1973 4 3 6 8 S ~~ ABSTRACT A Stand-Alone Alphanumeric CRT Teleprocessor Unit for a Hewlett-Packard 2114B Minicomputer. (August.... The teleprocessor allows the display of over 400 alphanumeric characters in a 5 X 7 dot matrix font on an X-Y oscilloscope. Up to 32 lines of up to 32 characters per line are allowed. Alphanumeric data in ASCII format is used as input and output...

Burrage, George Richard

2012-06-07

119

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

NASA Astrophysics Data System (ADS)

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 STI dry etching process is composed of two or three steps, such as the ARC etch, the hard-mask etch, and the Si etch. In order to etch multi-stacked layer (ARC, Oxide hard-mask (SiO2), Si 3N 4 as CMP stopping layer, and Si), we have controlled the parameters of etching (plasma power, gas, and pressure). In the SiO II hard-mask and Si 3N 4 layer etching process, we use a mixture chemistry of CF 4, CHF 3, O II, and Ar and get an optimized condition for the multi-layer system. The SiO II layer is role of mask for Si layer because the selectivity between SiO II and Si is superior to others. Finally, we get a good horizontal and vertical profile of STI by using a mixture chemistry of Cl II, HBr, and O II.

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

2008-03-01

120

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

121

77 FR 14006 - Proposed Development of the Alaska Stand Alone Gas Pipeline Project (ASAP), From the North Slope...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Proposed Development of the Alaska Stand Alone Gas Pipeline Project (ASAP), From the North Slope to South Central Alaska, Draft Environmental Impact...1, 2012. William Keller, North Branch Chief, Alaska...

2012-03-08

122

CEPH Accreditation of Stand-Alone Baccalaureate Programs: A Preliminary Mapping Exercise.  

PubMed

The purpose of this article is to provide a brief background of quality assurance efforts in health education, provide a brief overview of the new Council on Education for Public Health (CEPH) accreditation process for stand-alone baccalaureate public health programs that prepare health education specialists, and describe the experience of two academic programs in reviewing their curricula for coverage of the newly approved CEPH requirements. The University of Alabama and the University of North Carolina Wilmington undertook a curriculum mapping exercise identifying which courses in their programs Introduced, Reinforced, and/or Covered each of the Critical Components Elements identified by CEPH. The mapping process is described, and recommendations for other programs considering accreditation under the newly adopted CEPH standards are provided. PMID:24898243

Figueroa, Jorge L; Birch, David A; Rasar King, Laura; Cottrell, Randall R

2015-01-01

123

Metabolomic analysis via reversed-phase ion-pairing liquid chromatography coupled to a stand alone orbitrap mass spectrometer  

PubMed Central

We present a liquid chromatography-mass spectrometry (LC-MS) method that capitalizes on the mass-resolving power of the orbitrap to enable sensitive and specific measurement of known and unanticipated metabolites in parallel, with a focus on water soluble species involved in core metabolism. The reversed phase LC method, with a cycle time 25 min, involves a water-methanol gradient on a C18 column with tributylamine as the ion pairing agent. The MS portion involves full scans from 85 – 800 m/z at 1 Hz and 100,000 resolution in negative ion mode on a stand alone orbitrap (“Exactive”). The median limit of detection, across 80 metabolite standards, was 5 ng/mL with linear range typically ? 100-fold. For both standards and a cellular extract from Saccharomyces cerevisiae (Baker’s yeast), the median inter-run relative standard deviation in peak intensity was 8%. In yeast exact, we detected 137 known compounds, whose 13C-labeling patterns could also be tracked to probe metabolic flux. In yeast engineered to lack a gene of unknown function (YKL215C), we observed accumulation of an ion of m/z 128.0351, which we subsequently confirmed to be oxoproline, resulting in annotation of YKL215C as an oxoprolinase. These examples demonstrate the suitability of the present method for quantitative metabolomics, fluxomics, and discovery metabolite profiling. PMID:20349993

Lu, Wenyun; Clasquin, Michelle F.; Melamud, Eugene; Amador-Noguez, Daniel; Caudy, Amy A.; Rabinowitz, Joshua D.

2010-01-01

124

Vector controlled induction machines for stand-alone wind energy applications  

Microsoft Academic Search

This paper describes the system and control structures for vector controlled induction generators used for variable speed, wind energy conversion (WEC) systems. The paper focuses on WEC systems feeding an isolated load or weak grid since for such systems the generated voltage and power flow must be regulated by the WEC system itself and the control structures are not trivial.

R. S. Pena; R. J. Cardenas; G. M. Asher; J. C. Clare

2000-01-01

125

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

126

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.

127

Review of stand-alone photovoltaic application projects sponsored by US DOE and US AID  

NASA Astrophysics Data System (ADS)

Experience with dc photovoltaic systems (without backup power) and ranging in output from 23 to 3,500 peak watts, in a wide range of environmental conditions and with a wide range of insolation, is described. Cooperation of NASA with other government agencies resulted in the installation of an air pollution monitor in New Jersey, a seismic sensor in Hawaii, power for lookout towers in national forests in California, an electric power system for a Papago Indian village in Arizona, and a power system for a grain mill and water pump in Tangaye, Upper Volta. Significant operational results are discussed and system reliability is assessed for the 20 experimental systems installed since 1976. Additional systems to be installed overseas are highlighted, and economic factors are considered.

Bifano, W. J.

128

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

129

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

130

Dynamic modeling and control of a cascaded active battery\\/ultra-capacitor based vehicular power system  

Microsoft Academic Search

This paper presents an active hybrid battery\\/ultra-capacitor based vehicular power system. The stand alone battery system may not be sufficient to satisfy peak demand periods during transients in HEVs. An ultra-capacitor bank can supply or recapture a large burst of power since it can be used with high C-rates. Active battery\\/ultra-capacitor hybrid model provides a better solution in terms of

Omer Onar; Alireza Khaligh

2008-01-01

131

Wound Rotor Induction Generator With Sensorless Control and Integrated Active Filter for Feeding Nonlinear Loads in a Stand-Alone Grid  

Microsoft Academic Search

This paper describes a vector control scheme for a stand-alone generator based on a wound rotor induction machine with rotor side control. The stand-alone generator refers to an isolated grid feeding a local load. The primary objective of the control scheme is to maintain constant voltage and frequency at the output of the generator irrespective of prime mover speed variation.

Amit Kumar Jain; V. T. Ranganathan

2008-01-01

132

A Field Study Assessing Control of Broiler Coccidiosis by Paracox™ Vaccination or by Toltrazuril (Baycox®) Stand-Alone Treatment  

Microsoft Academic Search

Toltrazuril (Baycox®) stand-alone treatment and Paracox-5 (live attenuated vaccine) were assessed in a field trial for broiler\\u000a coccidiosis control. The feed did not contain coccidiostats or antimicrobial performance enhancers. Fifteen farms encompassing\\u000a 90 flocks were followed over three trial episodes (Vaccination-1, Toltrazuril and Vaccination-2). Each episode included two\\u000a successive flocks\\/growouts. Daily weight gain, feed conversion ratio, production number and mortality

M. Claeskens; W. Verdonck; H. Heesen; R. Froyman; A. Torres

2007-01-01

133

A wind-powered seawater reverse-osmosis system without batteries  

Microsoft Academic Search

The development of small-scale stand-alone desalination systems is important to communities on islands and in isolated inland areas. In such places, electricity supplies are often expensive and unreliable, while the wind resource is abundant. The system presented here comprises a 2.2 kW wind turbine generator powering a variable-flow Reverse osmosis (RO) desalination unit. It is highly efficient, rugged, built with

Marcos S. Miranda; David Infield

2003-01-01

134

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

NASA Technical Reports Server (NTRS)

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

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

1978-01-01

135

Design and techno-economical optimization for hybrid PV\\/wind system under various meteorological conditions  

Microsoft Academic Search

The optimal design of the renewable energy system can significantly improve the economical and technical performance of power supply. In this paper, the technical-economic optimization study of a stand-alone hybrid PV\\/wind system (HPWS) in Corsica Island is presented.Therefore, the primary objective of this study is to estimate the appropriate dimensions of a stand-alone HPWS that guarantee the energy autonomy of

S. Diaf; G. Notton; M. Belhamel; M. Haddadi; A. Louche

2008-01-01

136

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

137

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

138

Post-Processing in Cardiovascular Computed Tomography: Performance of a Client Server Solution versus a Stand-Alone Solution.  

PubMed

Purpose: To compare the performance of server-based (CSS) versus stand-alone post-processing software (ES) for the evaluation of cardiovascular CT examinations (cvCT) and to determine the crucial steps. Materials and Methods: Data of 40 patients (20 patients for coronary artery evaluation and 20 patients prior to transcatheter aortic valve implantation [TAVI]) were evaluated by 5 radiologists with CSS and ES.?Data acquisition was performed using a dual-source 128-row CT unit (SOMATOM Definition Flash, Siemens, Erlangen, Germany) and a 64-row CT unit (Brilliance 64, Philips, Hamburg, Germany). The following workflow was evaluated: Data loading, aorta and coronary segmentation, curved multiplanar reconstruction (cMPR) and 3?D volume rendering technique (3D-VRT), measuring of coronary artery stenosis and planimetry of the aortic annulus. The time requirement and subjective quality for the workflow were evaluated. Results: The coronary arteries as well as the TAVI data could be evaluated significantly faster with CSS (5.5?±?2.9?min and 8.2?±?4.0?min, respectively) than with ES (13.9?±?5.2?min and 15.2?±?10.9?min, respectively, p??0.01). Segmentation of the aorta (CSS: 1.9?±?2.0?min, ES: 3.7?±?3.3?min), generating cMPR of coronaries (CSS: 0.5?±?0.2?min, ES: 5.1?±?2.6?min), aorta and iliac vessels (CSS: 0.5?±?0.4?min and 0.4?±?0.4?min, respectively, ES: 1.6?±?0.7?min and 2.8?±?3?min, respectively) could be performed significantly faster with CSS than with ES with higher quality of cMPR, measuring of coronary stenosis and 3D-VRT (p?stand-alone solutions (ES), cardiovascular CT datasets can be evaluated reliably.•?Evaluation of cardiovascular CT can be performed faster and better with CSS than with ES.•?In particular the generating of curved reconstructions is faster with CSS than with ES.•?Segmentation of data is a crucial step for semiautomatic software (CSS and ES). Citation Format: •?Lücke C, Foldyna B, Andres C et?al. Post-Processing in Cardiovascular Computed Tomography: Performance of a Client Server Solution versus a Stand-Alone Solution. Fortschr Röntgenstr 2014; 186: 1111?-?1121. PMID:25122171

Lücke, C; Foldyna, B; Andres, C; Boehmer-Lasthaus, S; Grothoff, M; Nitzsche, S; Gutberlet, M; Lehmkuhl, L

2014-12-01

139

Thermoelectric generator and solid-state battery for stand-alone microsystems  

Microsoft Academic Search

This paper presents a thermoelectric (TE) generator and a solid-state battery for powering microsystems. Prototypes of TE generators were fabricated and characterized. The TE generator is a planar microstructure based on thin films of n-type bismuth telluride (Bi2Te3) and p-type antimony telluride (Sb2Te3), which were deposited using co-evaporation. The measurements on selected samples of Bi2Te3 and Sb2Te3 thin films indicated

J P Carmo; J F Ribeiro; M F Silva; L M Goncalves; J H Correia

2010-01-01

140

Bimode uninterruptible power supply compatibility in renewable hybrid energy systems  

SciTech Connect

Inverters installed in renewable hybrid energy systems are typically used in a stand-alone mode to supply ac power to loads from battery storage when the engine-generator is not being used. Similarities in topology and in the performance requirements of the standby uninterruptible power supply (UPS) system and the hybrid system suggest the UPS could be used in hybrid energy systems. Another alternative to inverters with add-on charging circuits or standby UPS hardware is the Bimode UPS. The bimode UPS uses common circuitry and power components for dc to ac inversion and battery charging. It also provides an automatic and nearly instantaneous ac power transfer function when the engine-generator is started or stopped. The measured operating and transfer characteristics of a bimode UPS in a utility system and in a hybrid system are presented. The applicability of the bimode UPS to hybrid systems and its compatibility in a PV/engine-generator hybrid system are given.

Bower, W. (Sandia National Labs., Albuquerque, NM (USA)); O'Sullivan, G. (Abacus Controls, Inc., Somerville, NJ (USA))

1990-08-01

141

Chapter [4.29] Headway Stand-Alone Manual Load Photoresist Spinner  

E-print Network

825 (G-Line) 2200 ~2.0 5 SPR-220 -7.0 (G-line-broadband) 1800 ~10.0 6 495 PMMA A2 4000 ~.05 to .06 7), before attempting to run the spinner. Do not touch any moving parts. 5.2 EPO red button: Cuts power of (um) 1 OiR 10i (I-Line) 4100 ~ 1.1 2 OCG 825 (G-Line) 5000 ~ 1.3 3 OiR 10i (I-Line) 1300 ~2.0 4 OCG

Healy, Kevin Edward

142

Control strategies for enhanced power smoothing in wind energy systems using a flywheel driven by a vector-controlled induction machine  

Microsoft Academic Search

This paper presents a novel control strategy for power smoothing in wind energy applications, especially those feeding a stand-alone load. The system is based on a vector-controlled induction machine driving a flywheel and addresses the problem of regulating the DC-link system voltage against both input power surges\\/sags from a wind turbine or sudden changes in load demand. The control is

Roberto Cárdenas; Rubén Peña; Greg Asher; Jon Clare

2001-01-01

143

Stand Alone Air Cleaners: Evaluation and Implications Matthew Ward, Jeffrey A. Siegel, Richard L. Corsi  

E-print Network

systems, deposition to indoor surfaces, and air exchange. The air exchange rate, volumetric flow rate competition by particle deposition with indoor surfaces and removal to HVAC filters. INTRODUCTION Growing for rapid removal of indoor fine particles, with potential use for shelter-in-place strategies following

Siegel, Jeffrey

144

Alignment of the CMS silicon strip tracker during stand-alone commissioning  

Microsoft Academic Search

The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us

W. Adam; T. Bergauer; M. Dragicevic; M. Friedl; R. Frühwirth; S. Hänsel; J. Hrubec; M. Krammer; M. Oberegger; M. Pernicka; S. Schmid; R. Stark; H. Steininger; D. Uhl; W. Waltenberger; E. Widl; P. Van Mechelen; M. Cardaci; W. Beaumont; E. de Langhe; E. A. de Wolf; E. Delmeire; M. Hashemi; O. Bouhali; O. Charaf; B. Clerbaux; J.-P. Dewulf; S. Elgammal; G. Hammad; G. de Lentdecker; P. Marage; C. Vander Velde; P. Vanlaer; J. Wickens; V. Adler; O. Devroede; S. DeWeirdt; J. D'Hondt; R. Goorens; J. Heyninck; J. Maes; Matthias Ulrich Mozer; S. Tavernier; L. Van Lancker; P. Van Mulders; I. Villella; C. Wastiels; J.-L. Bonnet; G. Bruno; B. DeCallatay; B. Florins; A. Giammanco; G. Gregoire; Th Keutgen; D. Kcira; V. Lemaitre; D. Michotte; O. Militaru; K. Piotrzkowski; L. Quertermont; V. Roberfroid; X. Rouby; D. Teyssier; E. Daubie; E. Anttila; S. Czellar; P. Engström; J. Härkönen; V. Karimäki; J. Kostesmaa; A. Kuronen; T. Lampén; T. Lindén; P.-R. Luukka; T. Mäenää; S. Michal; E. Tuominen; J. Tuominiemi; M. Ageron; G. Baulieu; A. Bonnevaux; G. Boudoul; E. Chabanat; E. Chabert; R. Chierici; D. Contardo; R. Della Negra; T. Dupasquier; G. Gelin; N. Giraud; G. Guillot; N. Estre; R. Haroutunian; N. Lumb; S. Perries; F. Schirra; B. Trocme; S. Vanzetto; J.-L. Agram; R. Blaes; F. Drouhin; J.-P. Ernenwein; J.-C. Fontaine; J.-D. Berst; J.-M. Brom; F. Didierjean; U. Goerlach; P. Graehling; L. Gross; J. Hosselet; P. Juillot; A. Lounis; C. Maazouzi; C. Olivetto; R. Strub; P. Van Hove; G. Anagnostou; R. Brauer; H. Esser; L. Feld; W. Karpinski; K. Klein; C. Kukulies; J. Olzem; A. Ostapchuk; D. Pandoulas; G. Pierschel; F. Raupach; S. Schael; G. Schwering; D. Sprenger; M. Thomas; M. Weber; B. Wittmer; M. Wlochal; F. Beissel; E. Bock; G. Flugge; C. Gillissen; T. Hermanns; D. Heydhausen; D. Jahn; G. Kaussen; A. Linn; L. Perchalla; M. Poettgens; O. Pooth; A. Stahl; M. H. Zoeller; P. Buhmann; E. Butz; G. Flucke; R. Hamdorf; J. Hauk; R. Klanner; U. Pein; P. Schleper; G. Steinbrück; P. Blüm; W. DeBoer; A. Dierlamm; G. Dirkes; M. Fahrer; M. Frey; A. Furgeri; F. Hartmann; S. Heier; K.-H. Hoffmann; J. Kaminski; B. Ledermann; T. Liamsuwan; S. Müller; Th Müller; F.-P. Schilling; H.-J. Simonis; P. Steck; V. Zhukov; P. Cariola; G. DeRobertis; R. Ferorelli; L. Fiore; M. Preda; G. Sala; L. Silvestris; P. Tempesta; G. Zito; D. Creanza; N. DeFilippis; M. DePalma; D. Giordano; G. Maggi; N. Manna; S. My; G. Selvaggi; S. Albergo; M. Chiorboli; S. Costa; M. Galanti; N. Giudice; N. Guardone; F. Noto; R. Potenza; M. A. Saizu; V. Sparti; C. Sutera; A. Tricomi; C. Tuvè; M. Brianzi; C. Civinini; F. Maletta; F. Manolescu; M. Meschini; S. Paoletti; G. Sguazzoni; B. Broccolo; V. Ciulli; R. D'Alessandro E. Focardi; S. Frosali; C. Genta; G. Landi; P. Lenzi; A. Macchiolo; N. Magini; G. Parrini; E. Scarlini; G. Cerati; P. Azzi; N. Bacchetta; A. Candelori; T. Dorigo; A. Kaminsky; S. Karaevski; V. Khomenkov; S. Reznikov; M. Tessaro; D. Bisello; M. DeMattia; P. Giubilato; M. Loreti; S. Mattiazzo; M. Nigro; A. Paccagnella; D. Pantano; N. Pozzobon; M. Tosi; G. M. Bilei; B. Checcucci; L. Fanò; L. Servoli; F. Ambroglini; E. Babucci; D. Benedetti; M. Biasini; B. Caponeri; R. Covarelli; M. Giorgi; P. Lariccia; G. Mantovani; M. Marcantonini; V. Postolache; A. Santocchia; D. Spiga; G. Bagliesi; G. Balestri; L. Berretta; S. Bianucci; T. Boccali; F. Bosi; F. Bracci; R. Castaldi; M. Ceccanti; R. Cecchi; C. Cerri; A. S. Cucoanes; R. Dell'Orso; D. Dobur; S. Dutta; A. Giassi; S. Giusti; D. Kartashov; A. Kraan; T. Lomtadze; G. A. Lungu; G. Magazzù; P. Mammini; F. Mariani; G. Martinelli; A. Moggi; F. Palla; F. Palmonari; G. Petragnani; A. Profeti; F. Raffaelli; D. Rizzi; G. Sanguinetti; S. Sarkar; D. Sentenac; A. T. Serban; A. Soldani; P. Spagnolo; R. Tenchini; S. Tolaini; A. Venturi; P. G. Verdini; M. Vos; L. Zaccarelli; C. Avanzini; A. Basti; L. Benucci; A. Bocci; U. Cazzola; F. Fiori; S. Linari; M. Massa; A. Messineo; G. Segneri; G. Tonelli; P. Azzurri; J. Bernardini; L. Borrello; F. Calzolari; L. Foà; S. Gennai; F. Ligabue; G. Petrucciani; A. Rizzi; Z. Yang; F. Benotto; N. Demaria; F. Dumitrache; R. Farano; M. A. Borgia; R. Castello; M. Costa; E. Migliore; A. Romero; D. Abbaneo; M. Abbas; I. Ahmed; I. Akhtar; E. Albert; C. Bloch; H. Breuker; S. Butt; O. Buchmuller; A. Cattai; C. Delaere; M. Delattre; L. M. Edera; M. Eppard; M. Gateau; K. Gill; A.-S. Giolo-Nicollerat; R. Grabit; A. Honma; M. Huhtinen; K. Kloukinas; J. Kortesmaa; L. J. Kottelat; N. Leonardo; C. Ljuslin; M. Mannelli; L. Masetti; A. Marchioro; S. Mersi; L. Mirabito; J. Muffat-Joly; A. Onnela; C. Paillard; I. Pal; J. F. Pernot; P. Petagna; C. Piccut; M. Pioppi; H. Postema; R. Ranieri; D. Ricci; G. Rolandi; F. Ronga; C. Sigaud; A. Syed; P. Siegrist; P. Tropea; J. Troska; A. Tsirou; M. Vander Donckt; F. Vasey; E. Alagoz; C. Amsler; V. Chiochia; C. Regenfus; P. Robmann; J. Rochet

2009-01-01

145

Alignment of the CMS silicon strip tracker during stand-alone commissioning  

SciTech Connect

The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us to perform first alignment of the active silicon modules with the cosmic tracks using three different statistical approaches; validate the survey and laser alignment system performance; and test the stability of Tracker structures under various stresses and temperatures ranging from +15C to -15C. Comparison with simulation shows that the achieved alignment precision in the barrel part of the tracker leads to residual distributions similar to those obtained with a random misalignment of 50 (80) microns in the outer (inner) part of the barrel.

Adam, W.; et al.

2009-07-01

146

TeraHz tuning of whispering gallery modes in a PDMS, stand-alone, stretchable microsphere  

E-print Network

We report on tuning the optical whispering gallery modes in a poly dimethyl siloxane-based (PDMS) microsphere resonator by more than a THz. The PDMS microsphere system consists of a solid spherical resonator directly formed with double stems on either side. The stems act like tie-rods for simple mechanical stretching of the microresonator over tens of microns, resulting in tuning of the whispering gallery modes by one free spectral range. Further investigations demonstrate that the whispering gallery mode shift has a higher sensitivity (0.13 nm/{\\mu}N) to an applied force when the resonator is in its maximally stretched state compared to its relaxed state.

Madugani, Ramgopal; Ward, Jonathan M; Riordan, John Daniel; Coppola, Sara; Vespini, Veronica; Grilli, Simonetta; Finizio, Andrea; Ferraro, Pietro; Chormaic, Síle Nic

2012-01-01

147

Stand-alone spacecraft attitude determination using real flight GPS data from UOSAT-12  

NASA Astrophysics Data System (ADS)

This paper presents the results of an experimental attitude determination system employing GPS (Global Positioning System), using phase difference data logged in orbit on the UoSAT-12 minisatellite, which was launched in 1999. The basics of GPS attitude determination are described, and two attitude determination algorithms are described and compared: one based on least squares estimation, and the other based on Kalman Filtering. The algorithm developed for resolving integer ambiguities in the carrier phase differences is tested to achieve instantaneous attitude from a set of only four measurements collected from two antenna baselines. A quaternion estimator based on a standard extended Kalman filter (qEKF) uses all GPS measurements to enable continued attitude determination taking into account the spacecraft dynamics. The attitude information derived from on-board magnetometers and a horizon sensor is used to evaluate the results of GPS attitude determination. Most recently, the LSQ attitude algorithms have been demonstrated in orbit and compared with the qEKF method.

Unwin, Martin; Purivigraipong, P.; da Silva Curiel, Alex; Sweeting, Martin

2002-07-01

148

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

149

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

150

A stand-alone method for anatomical localization of NIRS measurements.  

PubMed

Near-infrared spectroscopy (NIRS) is a non-invasive cortical imaging technique that provides many of the advantages of cortical fMRI with additional benefits of low cost, portability, and increased temporal resolution-features that make it potentially ideal for clinical diagnostic applications. However, the usefulness of NIRS is contingent on the ability to reliably localize the measured signal cortically. Although this can be achieved by supplementing NIRS data collection with an MRI scan, a much more appealing alternative is to use a portable magnetic measuring system to record the locations of optodes. Previous work has shown that optode skull measurements can be projected to the brain consistently within reasonable error bounds. Yet, as we show, if this is done without explicitly modeling the geometry of the holder securing the NIR optodes to participants' heads, considerable bias in the projection loci results. Here, we describe an algorithm that not only overcomes this bias but also corrects for measurement error in both optode position and skull reference points (which are used to register the measurements to standard brain templates) by applying geometric constraints. This method has been implemented as part of our NIRS Analysis Package (NAP), a public domain Matlab toolbox for analysis of NIRS data. PMID:21459146

Fekete, Tomer; Rubin, Denis; Carlson, Joshua M; Mujica-Parodi, Lilianne R

2011-06-15

151

Standing Alone in Judgment  

ERIC Educational Resources Information Center

In this article, Mark Freado and Howard Bath present the case of an 11 year boy who had been arrested and charged with the murder of his two-year-old cousin. Because of the severity of the criminal charge against this boy, and despite his age, a transfer hearing was set to determine whether he would be tried as a juvenile or an adult. Such…

Freado, Mark D.; Bath, Howard I.

2014-01-01

152

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

PubMed

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. PMID:23940838

Chartier, Matthieu; Chénard, Thierry; Barker, Jonathan; Najmanovich, Rafael

2013-01-01

153

Design description of the Schuchuli Village photovoltaic power system  

NASA Technical Reports Server (NTRS)

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.

1981-01-01

154

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

155

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

156

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...

157

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...

158

Design description of the Schuchuli village photovoltaic power system  

SciTech Connect

The engineering design of a stand-alone photovoltaic (PV) power system for the village of Schuchuli (Gunsight), Arizona, on the Papago Indian Reservation is described. The purpose of this experiment was to demonstrate that a stand-alone photovoltaic power system could provide dependable power for basic human needs in a remote village environment. The power system was designed as a limited energy, all 120-V(d.c.) system to which loads cannot be arbitrarily added. The system 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, and a sewing machine in the Domestic Services Building; and lights for each of the homes and communal buildings. In addition, a solar hot water heater was provided to supply hot water for the washing machine and communal laundry. The system employs automatic control systems which 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 loads at the expense of low priority loads as the main battery becomes depleted. The engineering design includes loads profiles and loads descriptions; an explanation of the PV array and battery sizing methodology; descriptions of the mechanical designs; electrical designs and descriptions of the array, battery, controls, instrumentation and distribution system; and a discussion of safety features.

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

1981-05-01

159

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

160

On the conversion of a mass selective detector from gas chromatography\\/mass spectrometry application to stand-alone, on-line, real-time mass spectrometry application  

Microsoft Academic Search

Development of initial versions of hardware and software for a Hewlett-Packard HP-5971A mass selective detector (MSD) was performed in order to improve its capabilities for monitoring gaseous waste streams. The development allowed for initial evaluation of the feasibility of the conversion of the MSD from an integrated gas chromatography\\/mass spectrometry (GC-MS) detector to a stand-alone, on-line, real-time mass spectrometry (SOR-MS)

M. Koch

1994-01-01

161

Photovoltaic Power System and Power Distribution Demonstration for the Desert RATS Program  

NASA Technical Reports Server (NTRS)

A stand alone, mobile photovoltaic power system along with a cable deployment system was designed and constructed to take part in the Desert Research And Technology Studies (RATS) lunar surface human interaction evaluation program at Cinder Lake, Arizona. The power system consisted of a photovoltaic array/battery system. It is capable of providing 1 kW of electrical power. The system outputs were 48 V DC, 110 V AC, and 220 V AC. A cable reel with 200 m of power cable was used to provide power from the trailer to a remote location. The cable reel was installed on a small trailer. The reel was powered to provide low to no tension deployment of the cable. The cable was connected to the 220 V AC output of the power system trailer. The power was then converted back to 110 V AC on the cable deployment trailer for use at the remote site. The Scout lunar rover demonstration vehicle was used to tow the cable trailer and deploy the power cable. This deployment was performed under a number of operational scenarios, manned operation, remote operation and tele-robotically. Once deployed, the cable was used to provide power, from the power system trailer, to run various operational tasks at the remote location.

Colozza, Anthony; Jakupca, Ian; Mintz, Toby; Herlacher, Mike; Hussey, Sam

2012-01-01

162

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

163

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

164

Anterior Cervical Discectomy and Fusion Using a Stand-Alone Polyetheretherketone Cage Packed with Local Autobone : Assessment of Bone Fusion and Subsidence  

PubMed Central

Objective It remains debatable whether cervical spine fusion cages should be filled with any kind of bone or bone substitute. Cortical and subcortical bone from the anterior and posterior osteophytes of the segment could be used to fill the cage. The purposes of the present study are to evaluate the clinical outcomes and radiological outcomes including bone fusion and subsidence that occurred after anterior cervical discectomy and fusion using a stand-alone cage packed with local autobone graft. Methods Thirty-one patients who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage packed with local autobone graft from July 2009 to december 2011 were enrolled in this study. Bone fusion was assessed by cervical plain radiographs and computed tomographic scan. Nonunion was evaluated according to the absence of bony bridge on computed tomographic scan. Subsidence was defined as a ?2 mm decrease of the interbody height at the final follow-up compared to that measured at the immediate postoperative period. Results Subsidence was observed in 7 patients (22.6%). Of 7 patients with subsidence greater 2 mm, nonunion was developed in 3. Three patients with subsidence greater 2 mm were related with endplate damage during intraoperative endplate preparation. Solid bone fusion was achieved in 28 out of 31 patients (90.3%). Conclusion With proper patient selection and careful endplate preparation, anterior cervical discectomy and fusion (ACDF) using a stand-alone PEEK cage packed with local autobone graft could be a good alternative to the standard ACDF techniques with plating. PMID:24278646

Park, Jeong-Ill; Kim, Kyoung-Tae; Sung, Joo-Kyung

2013-01-01

165

Prospective Randomized Controlled Trial of The Stabilis Stand Alone Cage (SAC) Versus Bagby and Kuslich (BAK) Implants for Anterior Lumbar Interbody Fusion  

PubMed Central

Background Degenerative disc disease is common and debilitating for many patients. If conservative extensive care fails, anterior lumbar interbody fusion has proven to be an alternative form of surgical management. The Stabilis Stand Alone Cage(SAC) was introduced as a method to obtain stability and fusion. The purpose of this study was to determine whether the Stabilis Stand Alone Cage (SAC) is comparable in safety and efficacy to the Bagby and Kuslich (BAK) device. Methods As part of a prospective, randomized, controlled FDA trial, 73 patients underwent anterior interbody fusion using either the SAC(56%) or the BAK device (44%). Results Background characteristics were similar between the two groups. There was no significant difference between the SAC and BAK groups in mean operative time or mean blood loss during surgery. Adverse event rates did not differ between the groups. Assessment of plain radiographs could not confirm solid fusion in 63% of control and 71% of study patients. Functional scores from Owestry and SF-36 improved in both groups by the two-year follow-up. There were no significant differences between the SAC and BAK patients with respect to outcome. Conclusions Both the Stabilis Stand Alone Cage and the BAK Cage provided satisfactory improvement in function and pain relief, despite less than expected radiographic fusion rates. The apparent incongruency between fusion rates and functional outcomes suggests that either radiographs underestimate the true incidence of fusion, or that patients are obtaining good pain relief and improved function despite a lower rate of fusion than previously reported. This was a Level III study.

Lavelle, William; McLain, Robert F.; Rufo-Smith, Candace; Gurd, David P.

2014-01-01

166

Biomechanical comparison of anterior lumbar interbody fusion: stand-alone interbody cage versus interbody cage with pedicle screw fixation - a finite element analysis  

PubMed Central

Background Anterior lumbar interbody fusion (ALIF) followed by pedicle screw fixation (PSF) is used to restore the height of the intervertebral disc and provide stability. Recently, stand-alone interbody cage with anterior fixation has been introduced, which eliminates the need for posterior surgery. We compared the biomechanics of the stand-alone interbody cage to that of the interbody cage with additional PSF in ALIF. Methods A three-dimensional, non-linear finite element model (FEM) of the L2-5 segment was modified to simulate ALIF in L3-4. The models were tested under the following conditions: (1) intact spine, (2) destabilized spine, (3) with the interbody cage alone (type 1), (4) with the stand-alone cage with anterior fixation (SynFix-LR®; type 2), and (5) with type 1 in addition to PSF (type 3). Range of motion (ROM) and the stiffness of the operated level, ROM of the adjacent segments, load sharing distribution, facet load, and vertebral body stress were quantified with external loading. Results The implanted models had decreased ROM and increased stiffness compared to those of the destabilized spine. The type 2 had differences in ROM limitation of 8%, 10%, 4%, and 6% in flexion, extension, axial rotation, and lateral bending, respectively, compared to those of type 3. Type 2 had decreased ROM of the upper and lower adjacent segments by 3-11% and 3-6%, respectively, compared to those of type 3. The greatest reduction in facet load at the operated level was observed in type 3 (71%), followed by type 2 (31%) and type 1 (23%). An increase in facet load at the adjacent level was highest in type 3, followed by type 2 and type 1. The distribution of load sharing in type 2 (anterior:posterior, 95:5) was similar to that of the intact spine (89:11), while type 3 migrated posterior (75:25) to the normal. Type 2 reduced about 15% of the stress on the lower vertebral endplate compared to that in type 1. The stress of type 2 increased two-fold compared to the stress of type 3, especially in extension. Conclusions The stand-alone interbody cage can provide sufficient stability, reduce stress in adjacent levels, and share the loading distribution in a manner similar to an intact spine. PMID:23890389

2013-01-01

167

Description of photovoltaic village power systems in the United States and Africa  

NASA Technical Reports Server (NTRS)

The paper describes the designs, hardware, and installations of NASA photovoltaic power systems in the village of Schuchuli in Arizona and Tangaye in Upper Volta, Africa. The projects were designed to demonstrate that current photovoltaic system technology can provide electrical power for domestic services for small, remote communities. The Schuchuli system has a 3.5 kW peak solar array which provides power for water pumping, a refrigerator for each family, lights, and community washing and sewing machines. The 1.8 kW Tangaye system provides power for pumping, flour milling, and lights in the milling building. Both are stand-alone systems operated by local personnel, and they are monitored by NASA to measure design adequacy and refine future designs.

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

1979-01-01

168

The Hardware Helper: Taking the Guesswork out of Multimedia Systems.  

ERIC Educational Resources Information Center

A computer expert describes two stand-alone, multimedia CD-ROM computer systems suitable for school and public libraries: a budget version for less than $2000 and a power version for about $3000. Recommends specific personal computer models, monitors, operating systems, processors, RAM (random access memory), hard drives, video subsystems, CD-ROM…

Jacso, Peter

1996-01-01

169

Determining the optimum solar water pumping system for domestic use, livestock water, or irrigation  

Technology Transfer Automated Retrieval System (TEKTRAN)

For several years we have field tested many different types of solar powered water pumping systems. In this paper, several steps are given to select a solar-PV water pumping system. The steps for selection of stand-alone water pumping system were: deciding whether a wind or solar water pumping sys...

170

Comparison between Two Different Cervical Interbody Fusion Cages in One Level Stand-alone ACDF: Carbon Fiber Composite Frame Cage Versus Polyetheretherketone Cage  

PubMed Central

Objective The authors conducted a retrospective study to compare the implantation of carbon fiber composite frame cages (CFCFCs) to the implantation of polyetheretherketone (PEEK) cages after anterior cervical discectomy for cervical degenerative disc disease. In addition, the predictive factors that influenced fusion or subsidence were investigated. Methods A total of 58 patients with single-level degenerative disc disease were treated with anterior cervical discectomy and implantation of stand-alone cages; CFCFCs were used in 35 patients, and PEEK cages were used in 23 patients. Preoperative and postoperative radiological and clinical assessments were performed. Results During the mean follow-up period of 41 months, fusion occurred in 43 patients (74.1%), and subsidence developed in 18 patients (31.0%). Pain decreased in all patients, and the patients' satisfaction rate was 75.9%. Neither fusion nor subsidence was related to the clinical outcome. There were no significant differences in the clinical and radiological outcomes between the CFCFC and the PEEK cage groups. Smoking history (p=0.023) was significantly associated with pseudarthrosis, and cage height (?7mm) (p=0.037) were significantly associated with subsidence. Conclusion The clinical and radiological results were similar between the CFCFC and the PEEK cage groups. Fusion or subsidence did not affect the clinical outcomes. Smoking history and cage height (?7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages. PMID:25346758

Yoo, Minwook; Kim, Wook-Ha; Hyun, Seung-Jae; Jahng, Tae-Ahn; Kim, Hyun-Jib

2014-01-01

171

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

172

Integrating an embedded system in a microwave moisture meter  

Technology Transfer Automated Retrieval System (TEKTRAN)

The conversion of a PC- or laptop-controlled microwave moisture meter to a stand-alone meter hosting its own embedded system is discussed. The moisture meter measures the attenuation and phase shift of low power microwaves traversing the sample, from which the dielectric properties are calculated. T...

173

Integrating an Embedded System within a Microwave Moisture Meter  

Technology Transfer Automated Retrieval System (TEKTRAN)

In this paper, the conversion of a PC or laptop-controlled microwave moisture meter to a stand-alone meter hosting its own embedded system is discussed. The moisture meter uses low-power microwaves to measure the attenuation and phase shift of the sample, from which the dielectric properties are cal...

174

Low-frequency switching voltage regulators for terrestrial photovoltaic systems  

NASA Technical Reports Server (NTRS)

The photovoltaic technology project and the stand alone applications project are discussed. Two types of low frequency switching type regulators were investigated. The design, operating characteristics and field application of these regulators is described. The regulators are small in size, low in cost, very low in power dissipation, reliable and allow considerable flexibility in system design.

Delombard, R.

1984-01-01

175

Mid-term Clinical Outcomes of Stand-alone Posterior Interbody Fusion with Rectangular Cages: A 4-year-minimum Follow-up  

PubMed Central

Objective We sought to determine minimum 4 years of clinical outcomes including fusion rate, revision rate and complications of patients who underwent placement of rectangular stand-alone cages. Methods Thirty-three cases of degenerative spine that had been followed for at least 4-years were reviewed retrospectively. Cages were inserted at L4-L5 level or L5-S1 in 27 or in 6 cases respectively. Visual analogue scale (VAS), Odom's criteria, fusion rate, intervertebral disc height and lumbar lordosis were determined pre- and post-operatively on standing x-rays. Amount of intra- and postoperative blood loss, total volume transfused, duration of surgery and perioperative complications were also evaluated. Results The mean VAS score of back pain and sciatica were improved from 8.0 and 7.0 points to 3.4 and 2.4 during 1 years follow-up visit and the scores was raised gradually. Also, during the follow-up, 94% of patients showed excellent or good outcomes by the Odom's criteria. Intervertebral disc height was increased from 8.2±1.4mm to 9.2±1.9mm at the first year of follow-up, however, found to be decreased and stabilized to 8.3±1.8mm after 2 years. The fusion rate was approximately 91% after 4 year postoperative. The segmental angle of lordosis was increased significantly by two years but it was not maintained after four years. A statistically insignificant change in total lumbar lordosis was also observed. Three patients (9%) had experienced perioperative complications. Conclusion The use of rectangular stand-alone cages for posterior lumbar interbody fusion (PLIF) resulted in a various degree of subsidence and demonstrate very low complication rate, high functional stability and improved clinical outcomes in patients with degenerative lumbar disc disease. PMID:24757473

Cho, Kyung Rae; Lee, Sun-Ho; Kim, Eun Sang

2013-01-01

176

Alternative energy facilities based on site matching and generation unit sizing for remote area power supply  

Microsoft Academic Search

This paper presents the decision support technique and influencing factors in the design of an integrated solar-wind power system for stand-alone applications. Results of investigations on application of alternative energy facility like wind, photovoltaic (PV), and Integration of wind–PV power generating systems for Remote Area Power Supply have been presented. A weather model-based site matching of equipment and a simple

Pradeep K. Katti; Mohan K. Khedkar

2007-01-01

177

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

178

Dynamic modeling of hybrid energy storage systems coupled to photovoltaic generation in residential applications  

Microsoft Academic Search

A model of a photovoltaic (PV) powered residence in stand-alone configuration was developed and evaluated. The model assesses the sizing, capital costs, control strategies, and efficiencies of reversible fuel cells (RFC), batteries, and ultra-capacitors (UC) both individually, and in combination, as hybrid energy storage devices. The choice of control strategy for a hybrid energy storage system is found to have

James D. Maclay; Jacob Brouwer; G. Scott Samuelsen

2007-01-01

179

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

Microsoft Academic Search

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

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

1999-01-01

180

Community Health Workers and Stand-Alone or Integrated Case Management of Malaria: A Systematic Literature Review  

PubMed Central

A systematic literature review was conducted to assess the effectiveness of strategies to improve community case management (CCM) of malaria. Forty-three studies were included; most (38) reported indicators of community health worker (CHW) performance, 14 reported on malaria CCM integrated with other child health interventions, 16 reported on health system capacity, and 13 reported on referral. The CHWs are able to provide good quality malaria care, including performing procedures such as rapid diagnostic tests. Appropriate training, clear guidelines, and regular supportive supervision are important facilitating factors. Crucial to sustainable success of CHW programs is strengthening health system capacity to support commodity supply, supervision, and appropriate treatment of referred cases. The little evidence available on referral from community to health facility level suggests that this is an area that needs priority attention. The studies of integrated CCM suggest that additional tasks do not reduce the quality of malaria CCM provided sufficient training and supervision is maintained. PMID:24957538

Paintain, Lucy Smith; Willey, Barbara; Kedenge, Sarah; Sharkey, Alyssa; Kim, Julia; Buj, Valentina; Webster, Jayne; Schellenberg, David; Ngongo, Ngashi

2014-01-01

181

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

1999-12-01

182

JChainsAnalyser: an ImageJ-based stand-alone application for the study of magneto-rheological fluids  

NASA Astrophysics Data System (ADS)

JChainsAnalyser is a Java-based program for the analysis of two-dimensional images of magneto-rheological fluids (MRF) at low concentration of particles obtained using the video-microscopy technique. MRF are colloidal dispersions of micron-sized polarizable particles in a carrier fluid with medium to low viscosity. When a magnetic field is applied to the suspension, the particles aggregate forming chains or clusters. Aggregation dynamics [P. Domínguez-García, S. Melle, J.M. Pastor, M.A. Rubio, Phys. Rev. E 76 (2007) 051403] and morphology of the aggregates [P. Domínguez-García, S. Melle, M.A. Rubio, J. Colloid Interface Sci. 333 (2009) 221-229] have been studied capturing images of the fluid and analyzing them by using this software. The program allows to analyze automatically the MRF images by means of an adequate combination of different imaging methods, while magnitudes and statistics are calculated and saved in data files. It is possible to run the program on a desktop computer, using the GUI (graphical user interface), or in a cluster of processors or remote computer by means of command-line instructions. Program summaryProgram title: JChainsAnalyser Catalogue identifier: AEDT_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDT_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC license, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 79 071 No. of bytes in distributed program, including test data, etc.: 4 367 909 Distribution format: tar.gz Programming language: Java 2 Computer: Any computer with Java Runtime Environment (JRE) installed Operating system: Any OS with Java Runtime Environment (JRE) installed RAM: Typically, 3.3 MB Classification: 23 External routines: ImageJ, ij-imageIO, jdom, L2FProd Nature of problem: The video-microscopy technique usually produces quite a big quantity of images to analyze. Although ImageJ gives the required filters and methods for image analysis, it fails when a large number of images is used. Moreover, an adequate combination of filters is needed for the segmentation and binarization of this kind of images. Solution method: JChainsAnalyser filters and analyses any quantity of MRF images automatically, so the application can be run on a desktop computer or using a cluster of processors. It can be run in a desktop computer using the GUI (graphical user interface) or by a command-line interface. JChainsAnalyser uses XML files to define input/output data and Java to ensure portability between operating systems. It also utilizes an image algorithm based on the application of different and adaptative ImageJ's filters. Running time: The test run provided takes only a few seconds.

Domínguez-García, P.; Rubio, M. A.

2009-10-01

183

A novel robust TiN\\/AHO\\/TiN capacitor and CoSi2 cell pad structure for 70nm stand-alone and embedded DRAM technology and beyond  

Microsoft Academic Search

For the first time, a novel robust (square-shape cylinder type) TiN\\/AHO (Al2O3-HfO2)\\/TiN capacitor with Co-silicide on landing cell pad suitable for both stand-alone and embedded DRAMs are successfully developed with 88nm (pitch 176nm) feature size, which is the smallest feature size ever reported in DRAM technology, using ArF lithography for aiming 70nm stand-alone and embedded DRAM technology. The capacitor with

J. M. Park; Y. S. Hwang; D. S. Hwang; H. K. Hwang; S. H. Lee; G. Y. Kim; M. Y. Jeong; B. J. Park; S. E. Kim; M. H. Cho; D. I. Kim; J.-H. Chung; I. S. Park; C.-Y. Yoo; J. H. Lee; B. Y. Nam; Y. R. Park; C.-S. Kim; M.-C. Sun; J.-H. Ku; S. Choi; H. S. Kim; Y. G. Park; Kinam Kim

2002-01-01

184

Neural network identification of power system transfer functions  

SciTech Connect

This paper describes an investigation into the use of a multilayered neural network for measuring the transfer function of a power system for use in power system stabilizer (PSS) tuning and assessing PSS damping. The objectives are to quickly and accurately measure the transfer function relating the electric power output to the AVR PSS reference voltage input of a system with the plant operating under normal conditions. In addition, the excitation signal used in the identification procedure is such that it will not adversely affect the terminal voltage or the system frequency. This research emphasized the development of a neural network that is easily trained and robust to changing system conditions. Performance studies of the trained neural network are described. Simulation studies suggest the practical feasibility of the algorithm as a stand-alone identification package and as a portion of a self-tuning algorithm requiring identification in the strategy. The same technique applied to a forward modeling scheme can be used to test the damping contribution from different control strategies.

Gillard, D.M.; Bollinger, K.E. [Univ. of Alberta, Edmonton, Alberta (Canada)] [Univ. of Alberta, Edmonton, Alberta (Canada)

1996-03-01

185

Design description of the Tangaye Village photovoltaic power system  

SciTech Connect

The engineering design of a stand alone photovoltaic (PV) powered grain mill and water pump for the village of Tangaye, Upper Volta is described. The socioeconomic effects of reducing the time required by women in rural areas for drawing water and grinding grain were studied. The suitability of photovoltaic technology for use in rural areas by people of limited technical training was demonstrated. The PV system consists of a 1.8-kW (peak) solar cell array, 540 ampere hours of battery storage, instrumentation, automatic controls, and a data collection and storage system. The PV system is situated near an improved village well and supplies d.c. power to a grain mill and a water pump. The array is located in a fenced area and the mill, battery, instruments, controls, and data system are in a mill building. A water storage tank is located near the well. The system employs automatic controls which provide battery charge regulation and system over and under voltage protection. This report includes descriptions of the engineering design of the system and of the load that it serves, a discussion of PV array and battery sizing methodology, descriptions of the mechanical and electrical designs including the array, battery, controls, and instrumentation, and a discussion of the safety features. The system became operational on March 1, 1979.

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

1982-06-01

186

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

NASA Technical Reports Server (NTRS)

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.

1981-01-01

187

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

188

DESIGN OF HYBRID-PHOTOVOLTAIC POWER GENERATOR, WITH OPTIMIZATION OF ENERGY MANAGEMENT  

Microsoft Academic Search

A methodology is developed for calculating the correct size of a photovoltaic (PV)-hybrid system and for optimizing its management. The power for the hybrid system comes from PV panels and an engine-generator – that is, a gasoline or diesel engine driving an electrical generator. The combined system is a stand-alone or autonomous system, in the sense that no third energy

M. Muselli; G. Notton; A. Louche

1999-01-01

189

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

190

LabVIEW remote control for a laser power\\/energy meter  

Microsoft Academic Search

LabVIEW is a consistent development and execution environment that provides a method to implement various test and measurements' systems containing stand alone laboratory instruments. This paper describes a virtual instrument created in LabVIEW that facilitates the control of a dual channel laser power\\/energy meter through a computer serial port, for accurate laser power\\/energy data logging and handling. The program has

Gabriel A. Ivan; Dan G. Sporea

2000-01-01

191

Phase 1 of the First Solar Small Power System Experiment (experimental System No. 1). Volume 1: Technical Studies for Solar Point-focusing, Distributed Collector System, with Energy Conversion at the Collector, Category C  

NASA Technical Reports Server (NTRS)

The technical and economic feasibility of a solar electric power plant for a small community is evaluated and specific system designs for development and demonstration are selected. All systems investigated are defined as point focusing, distributed receiver concepts, with energy conversion at the collector. The preferred system is comprised of multiple parabolic dish concentrators employing Stirling cycle engines for power conversion. The engine, AC generator, cavity receiver, and integral sodium pool boiler/heat transport system are combined in a single package and mounted at the focus of each concentrator. The output of each concentrator is collected by a conventional electrical distribution system which permits grid-connected or stand-alone operation, depending on the storage system selected.

Clark, T. B. (editor)

1979-01-01

192

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

193

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

194

Capacitive Self-Excitation in a Six-Phase Induction Generator for Small Hydro Power -- An Experimental Investigation  

Microsoft Academic Search

Results of an experimental investigation dealing with the behavior of a split wound 6-phase self-excited induction generator (SEIG) with capacitor excitation in conjunction to a stand-alone small hydro power scheme is presented. As predicted, the scheme is found offering high reliability, improved capability of voltage build-up and load withstanding along with acceptable efficiency. Results obtained show that the system has

G. K. Singh; K. B. Yadav; R. P. Saini

2006-01-01

195

An Overview of Power Electronics Applications in Fuel Cell Systems: DC and AC Converters  

PubMed Central

Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

Ali, M. S.; Kamarudin, S. K.; Masdar, M. S.; Mohamed, A.

2014-01-01

196

An Overview of Power Electronics Applications in Fuel Cell Systems: DC and AC Converters.  

PubMed

Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

2014-01-01

197

Development of a Multi-bus, Multi-source Reconfigurable Stirling Radioisotope Power System Test Bed  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration (NASA) has typically used Radioisotope Thermoelectric Generators (RTG) as their source of electric power for deep space missions. A more efficient and potentially more cost effective alternative to the RTG, the high efficiency 110 watt Stirling Radioisotope Generator 110 (SRG110) is being developed by the Department of Energy (DOE), Lockheed Martin (LM), Stirling Technology Company (STC) and NASA Glenn Research Center (GRC). The SRG110 consists of two Stirling convertors (Stirling Engine and Linear Alternator) in a dual-opposed configuration, and two General Purpose Heat Source (GPHS) modules. Although Stirling convertors have been successfully operated as a power source for the utility grid and as a stand-alone portable generator, demonstration of the technology required to interconnect two Stirling convertors for a spacecraft power system has not been attempted. NASA GRC is developing a Power System Test Bed (PSTB) to evaluate the performance of a Stirling convertor in an integrated electrical power system application. This paper will describe the status of the PSTB and on-going activities pertaining to the PSTB in the NASA Thermal-Energy Conversion Branch of the Power and On-Board Propulsion Technology Division.

Coleman, Anthony S.

2004-01-01

198

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

199

Photovoltaic solar power systems  

Microsoft Academic Search

An introduction into photovoltaic device theory and design is given to provide a background for discussing applications for solar power system. The potential for using silicon solar cells to provide large amounts of electrical power is shown and a proposed plan for developing solar power systems for a wide range of applications is described. Solar power systems utilized in remote

E. L. Ralph

1974-01-01

200

Stand-alone groundwater desalination system using reverse osmosis combined with a cooled greenhouse for use in arid and semi-arid zones of India  

Microsoft Academic Search

In many areas of northern India, salinity renders groundwater unsuitable for drinking and even for irrigation. Though membrane treatment can be used to remove the salt, there are some drawbacks to this approach e.g. (1) depletion of the groundwater due to over-abstraction, (2) saline contamination of surface water and soil caused by concentrate disposal and (3) high electricity usage. To

P. A. Davies; A. K. Hossain; P. Vasudevan

2009-01-01

201

Joint U.S./Brazilian hybrid power system (wind-PV-diesel) on Marajo Island  

SciTech Connect

A cooperative renewable energy project is underway between the U.S. Department of Energy (through the National Renewable Energy Laboratory, NREL), and the Federal Republic of Brazil (through the Centro de Pesquisas de Energia Eletrica, CEPEL). The objectives of this joint US/Brazilian program are to establish technical, institutional, and economic confidence in using renewable energy systems to meet the needs of the people of rural Brazil, to build ongoing partnerships beneficial to both countries, and to demonstrate the potential for large-scale rural electrification through the use of renewable energy systems. Phase 1 of this program resulted in the deployment of more than 700 photovoltaic (PV) electric lighting systems in the Brazilian states of Pernambuco and Ceara. Phase 2 of the program extends the pilot project into six additional Brazilian states and demonstrates a wider variety of stand-alone end uses, including the use of wind electric power generation for selected sites and applications. Additionally, Phase 2 also includes the development of two hybrid village power systems, including one comprising PV, wind, battery, and diesel power sources. This paper focuses on this hybrid system, which is located in the Amazon River delta.

Leboeuf, C.; Taylor, R.W.; Corbus, D. [National Renewable Energy Lab., Golden, CO (United States); Moszkowicz, M.; Lima, J.; Ribeiro, C. [CEPEL, Rio de Janeiro (Brazil)

1995-09-01

202

Space nuclear power systems  

NASA Technical Reports Server (NTRS)

Space nuclear power systems are considered for use in those particular spacecraft applications for which nuclear power systems offer unique advantages over solar and/or chemical space power systems. Both isotopic and reactor heated space electrical power units are described in an attempt to illustrate their operating characteristics, spacecraft integration aspects, and factory-to-end of mission operational considerations. The status of technology developments in nuclear power systems is presented. Some projections of those technologies are made to form a basis for the applications of space nuclear power systems to be expected over the next 10-15 years.

Carpenter, R. T.

1972-01-01

203

A knowledge-based approach to the design of integrated renewable energy systems  

Microsoft Academic Search

Integrated renewable systems utilize two or more renewable energy resources and end-use technologies to supply a variety of energy needs, often in a stand-alone mode. A knowledge-based design approach that minimizes the total capital cost at a preselected reliability level is presented. The reliability level is quantified by the loss of power supply probability. The procedure includes some resource-need matching

R. Ramakumar; I. Abouzahr; K. Ashenayi

1992-01-01

204

Solar powered desalination system  

E-print Network

efficiency for a PV system is a ratio of the electrical power output to the solarSolar Energy Calculator using Google Maps 23 Table 1.24: PV System Power Production Average Daily Irradiance (kWh/m2) Instillation Efficiencysolar-to-hydrogen (STH) conversion efficiency is 10%. (STH conversion efficiency is power

Mateo, Tiffany Alisa

2011-01-01

205

Power delivery system  

Microsoft Academic Search

This patent describes a power delivery system for connecting a transmission to an output shaft of an engine, the transmission including a dog clutch for establishing a power transmission route by the engagement of the dog clutch, the power delivery system comprising; a clutch for disconnecting the engagement between an output member of the fluid coupling and the output shaft

S. Moroto; S. Sakakibara

1987-01-01

206

International Space Station Power Systems  

NASA Technical Reports Server (NTRS)

This viewgraph presentation gives a general overview of the International Space Station Power Systems. The topics include: 1) The Basics of Power; 2) Space Power Systems Design Constraints; 3) Solar Photovoltaic Power Systems; 4) Energy Storage for Space Power Systems; 5) Challenges of Operating Power Systems in Earth Orbit; 6) and International Space Station Electrical Power System.

Propp, Timothy William

2001-01-01

207

Power System Dynamic Equivalents  

Microsoft Academic Search

This paper describes a method for determining a simplified equivalent mathematical representation of portions of a power system for transient stability analysis. The method leads to equations that do not correspond directly to a system composed of normal power system components. Conditions under which it is possible to obtain such an equivalent are given, and the results of applying the

Albert Chang; Mahmood Adibi

1970-01-01

208

Market assessment of photovoltaic power systems for agricultural applications in Morocco  

NASA Technical Reports Server (NTRS)

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.

1981-01-01

209

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

210

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

211

Space Nuclear Power Systems  

NASA Technical Reports Server (NTRS)

Fission power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system.

Houts, Michael G.

2012-01-01

212

Design Considerations for StandDesign Considerations for Stand--alone Haptic Interfacesalone Haptic Interfaces Communicating via UDP ProtocolCommunicating via UDP Protocol  

E-print Network

Microcontroller Ethernet Ethernet Interface Remote Computer Fig.2: System diagram Fig.3: Timing diagram for client mode operation running at 3800 Hz Overview Ã?This work was motivated by the need for high-speed and a 10 Mbps half-duplex Ethernet interface. Ã?Intense calculations involved in determining end effector

Tan, Hong Z.

213

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

214

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

215

Power Systems Decentralized Optimization  

NASA Astrophysics Data System (ADS)

The paper's aim is to explore both active and reactive power losses minimization and voltage stability by a decentralized strategy. The approach assumes that the grid is split into sub-systems; each sub-system is in charge of its own optimal solution using equivalents for the neighbors, so that information exchange is not required. Schedule interchanges among sub-systems have been added as constraints into the optimal formulation. Once the individual solutions are available, the corresponding settings are allocated to the corresponding equipment and a full power flow study is carried out to assure the steady-state preservation. Results are exhibited on two test power systems.

Ramirez, Juan M.; Vargas-Marín, Javier; Correa-Gutiérrez, Rosa E.

2014-12-01

216

TROPIX Power System Architecture  

NASA Technical Reports Server (NTRS)

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 first. Since the design is dependent on the performance of the photovoltaics, there is a comprehensive discussion of the appropriate models for cells and arrays. A trade study of the array operating voltage and its effect on array bus mass is also presented. A system architecture is developed which makes use of a combination of high efficiency switching power convertors and analog regulators. Mass and volume estimates are presented for all subsystems.

Manner, David B.; Hickman, J. Mark

1995-01-01

217

Lunar solar-power system: Commerical power  

Microsoft Academic Search

The proposed Lunar Solar-Power (LSP) System collects solar power on the moon. The power is converted to beams of microwaves and transmitted to fields of microwave receivers (rectennas) on Earth that provide electric power to local and regional power grids. LSP can provide abundant and low cost energy to Earth to sustain several centuries of economic development on Earth and

David R. Criswell

1995-01-01

218

Space Station Power System  

NASA Technical Reports Server (NTRS)

The strategies, reasoning, and planning guidelines used in the development of the United States Space Station Program are outlined. The power required to support Space Station missions and housekeeping loads is a key driver in overall Space Station design. conversely, Space Station requirements drive the power technology. Various power system technology options are discussed. The mission analysis studies resulting in the required Space Station capabilities are also discussed. An example of Space Station functions and a concept to provide them is presented. The weight, area, payload and altitude requirements on draft and mass requirements are described with a summary and status of key power systems technology requirements and issues.

Baraona, C. R.

1984-01-01

219

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

220

Dynamic Power Systems for Power Generation  

NASA Technical Reports Server (NTRS)

The characteristics of dynamic power systems have considerable potential value, especially for the space station. The base of technology that makes these dynamic power systems practical is reviewed. The following types of power-generating systems are examined herein: organic Rankine cycle, potassium Rankine cycle, Brayton cycle, and Stirling cycle.

English, R. E.

1984-01-01

221

Dynamic power systems for power generation  

NASA Astrophysics Data System (ADS)

The characteristics of dynamic power systems have considerable potential value, especially for the space station. The base of technology that makes these dynamic power systems practical is reviewed. The following types of power-generating systems are examined herein: organic Rankine cycle, potassium Rankine cycle, Brayton cycle, and Stirling cycle.

English, R. E.

1984-04-01

222

Exhibits Enhanced by Stand-Alone Computers.  

ERIC Educational Resources Information Center

Both the development and evaluation of one of a set of computer programs designed for use by visitors as adjuncts to museum exhibits are described. Museum displays used were (1) a static, behind-glass exhibit on evolution; (2) a hands-on primitive stone age tools exhibit; and (3) a Foucault pendulum. A computer placed next to each exhibit served…

Van Rennes, Eve C.

223

Chapter 2: Stand-alone Applications - TOPCAT  

NASA Astrophysics Data System (ADS)

Tool for OPerations on Catalogues And Tables or TOPCAT is a graphical viewer for table data. It offers a variety of ways to work with data tables, including a browser for the cell data, viewers for information about table and column metadata, dataset visualization, and even analysis. We discuss a small subset of TOPCAT's functionalities in this chapter. TOPCAT was originally developed as part of the Starlink program in the United Kingdom. It is now maintained by AstroGrid. The program is written in pure Java and available under the GNU General Public License. It is available for download and a version is included in the software distribution accompanying this book. TOPCAT is a GUI interface on top of the STIL library. A command line interface to this library, STILTS, described in Chapter 21 provides scriptable access to many of the capabilities described here. The purpose of this tutorial is to provide an overview of TOPCAT to the novice user. The best place to look for and learn about TOPCAT is the web page maintained by Mark B. Taylor. There, TOPCAT documentation is provided in HTML, PDF, via screen shots, etc. In this chapter we take the user through a few examples that give the general idea of how TOPCAT works. The majority of the functionality of TOPCAT is not included in this short tutorial. Our goal in this tutorial is to lead the reader through an exercise that would result in a publication quality figure (e.g. for a journal article). Specifically, we will use TOPCAT to show how the color-magnitude relation of a galaxy cluster compares to that of all galaxies in the Sloan Digital Sky Survey (York et al. 2000). This diagnostic is used not only in cluster finding, but its linear fit can provide insight into the age and/or metallicity of the oldest galaxies in galaxy clusters (which are some of the oldest galaxies in the Universe). The data we need for this exercise are: 1) the entire spectroscopic galaxy catalog from the SDSS, with galaxy positions, galaxy redshifts, and galaxy magnitudes and 2) galaxy members of a known galaxy cluster. For the former, we will download data directly from the SDSS servers to our local machine for analysis. For the latter, we will use TOPCAT's ability to call live cone search services.

Miller, C. J.

224

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

225

Stand-alone Open Source Software  

E-print Network

development & compliance · Training tool · Metric goal setting · Protocol development · Hardware monitoring, ladders and custom samples Analysis · Multiple batch processing of .fsa files · Multiple kit support · Peak location and quality assessment · Independent algorithm · Graphical display · CODIS CMF 3

Levin, Judith G.

226

AC power system breadboard  

NASA Technical Reports Server (NTRS)

The object of this program was to design, build, test, and deliver a high-frequency (20-kHz) Power System Breadboard which would electrically approximate a pair of dual redundant power channels of an IOC Space Station. This report describes that program, including the technical background, and discusses the results, showing that the major assumptions about the characteristics of this class of hardware (size, mass, efficiency, control, etc.) were substantially correct. This testbed equipment has been completed and delivered to LeRC, where it is operating as a part of the Space Station Power System Test Facility.

Wappes, Loran J.; Sundberg, R.; Mildice, J.; Peterson, D.; Hushing, S.

1987-01-01

227

Modeling and sizing optimization of hybrid photovoltaic/wind power generation system  

NASA Astrophysics Data System (ADS)

The rapid industrialization and growth of world's human population have resulted in the unprecedented increase in the demand for energy and in particular electricity. Depletion of fossil fuels and impacts of global warming caused widespread attention using renewable energy sources, especially wind and solar energies. Energy security under varying weather conditions and the corresponding system cost are the two major issues in designing hybrid power generation systems. In this paper, the match evaluation method (MEM) is developed based on renewable energy supply/demand match evaluation criteria to size the proposed system in lowest cost. This work is undertaken with triple objective function: inequality coefficient, correlation coefficient, and annualized cost of system. It provides optimum capacity of as many numbers of supplies as required to match with a load demand in lowest investment, so it can handle large-scale design problems. Meteorological data were collected from the city of Zabol, located in south-east of Iran, as a case study. Six types of wind turbine and also six types of PV modules, with different output powers and costs, are considered for this optimization procedure. A battery storage system is used to even out irregularities in meteorological data. A multi-objective particle swarm optimization algorithm has been used for the prediction of an optimized set of design based on the MEM technique. The results of this study are valuable for evaluating the performance of future stand-alone hybrid power system. It is worth mentioning that the proposed methodology can be effectively employed for any composition of hybrid energy systems in any locations taking into account the meteorological data and the consumer's demand.

Yazdanpanah, Mohammad-Ali

2014-03-01

228

Solar Powered Refrigeration System  

NASA Astrophysics Data System (ADS)

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Ewert, Michael K.; Bergeron, David J., III

2002-09-01

229

Solar Powered Refrigeration System  

NASA Technical Reports Server (NTRS)

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2002-01-01

230

Power Systems Development Facility  

SciTech Connect

In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, has routinely demonstrated gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This final report summarizes the results of the technology development work conducted at the PSDF through January 31, 2009. Twenty-one major gasification test campaigns were completed, for a total of more than 11,000 hours of gasification operation. This operational experience has led to significant advancements in gasification technologies.

Southern Company Services

2009-01-31

231

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

232

Autonomous power system brassboard  

NASA Technical Reports Server (NTRS)

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. However, there are elements of the brassboard which could be enhanced, thus improving system performance. Modifications and enhancements to improve the brassboard's operation are discussed.

Merolla, Anthony

1992-01-01

233

Automated Power-Distribution System  

NASA Technical Reports Server (NTRS)

Autonomous power-distribution system includes power-control equipment and automation equipment. System automatically schedules connection of power to loads and reconfigures itself when it detects fault. Potential terrestrial applications include optimization of consumption of power in homes, power supplies for autonomous land vehicles and vessels, and power supplies for automated industrial processes.

Ashworth, Barry; Riedesel, Joel; Myers, Chris; Miller, William; Jones, Ellen F.; Freeman, Kenneth; Walsh, Richard; Walls, Bryan K.; Weeks, David J.; Bechtel, Robert T.

1992-01-01

234

A simple mathematical description of an off-grid hybrid solarwind power generating system This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-print Network

/763 Abstract We give a detailed description of the energy balance equation for a stand-alone hybrid solar on the ground, to which the black electric wires are connected. Electric power from the wind turbine rotor electric energy from the wind turbine rotor and from the PV cells. In this particular study we are not conc

Blasone, Massimo

235

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

236

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.

Latorre, Victor R. (Tracy, CA); Watwood, Donald B. (Tracy, CA)

1994-01-01

237

NASA: Radioisotope Power Systems  

NSDL National Science Digital Library

This is a multimedia overview of RPS (radioisotope power systems), a type of nuclear energy technology that uses heat to produce electricity for powering spacecraft. The heat is produced by the natural radioactive decay of plutonium-238. RPS systems have been in use for more than 50 years, and could continue to support missions to some of the most extreme environments in the solar system. Advantages of RPS include: continuous operation over long-duration space missions, largely independent of changes in sunlight, temperature, charged particle radiation, or surface conditions like thick clouds or dust. This resource is part of NASA's Solar System Exploration website. It includes videos, 3D interactive animations, illustrations, schematics of RPS components, and fact sheets about how the technology has been used in past missions.

2012-10-30

238

Tidewater power system  

Microsoft Academic Search

A system for extracing power from the tides includes a dam constructed in a body of water subject to tidal flow for separating the body of water from a tidal basin between the dam and the shoreline. A plurality of water wheel assemblies are mounted on the dam and include mounting saddles for mounting water wheels for rotation about a

Dickman

1976-01-01

239

Power systems facility  

NASA Technical Reports Server (NTRS)

In 1984, the President directed NASA to undertake the development of Space Station Freedom, the next step in a broad-based U.S. civil space program to develop space-flight capabilities and to exploit space for scientific, technological, and commercial purposes. Under that direction, NASA awarded contracts in 1985 for concept definition and preliminary design studies. Those studies have been completed and the Space Station Freedom Program is now in the final design and development phase, leading to a permanently manned space station that will be operational in the mid-1990's. Here at the Lewis Research Center, with Rocketdyne, we are developing and building the S.S. Freedom electric power system (EPS) hardware and software. A major portion of the EPS will be tested at Lewis. The Power Systems Facility was specifically designed for testing the EPS and uses the latest in testing equipment.

1989-01-01

240

Electric power transmission systems  

Microsoft Academic Search

An updated edition (from 1972) of technical aspects exhibited by electric systems which transmit power from the generator to the loads. A new area covered is the calculation of short-circuit currents due to symetrical faults and their impact on the ratings of circuit-interrupting devices. Not only have problems been added, but the use of a computer (over a wide-range of

J. R. Eaton; E. Cohen

1983-01-01

241

Power control system and method  

DOEpatents

A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.

Steigerwald, Robert Louis (Burnt Hills, NY) [Burnt Hills, NY; Anderson, Todd Alan (Niskayuna, NY) [Niskayuna, NY

2008-02-19

242

Automated Power-Distribution System  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

243

Power delivery system  

SciTech Connect

This patent describes a power delivery system for connecting a transmission to an output shaft of an engine, the transmission including a dog clutch for establishing a power transmission route by the engagement of the dog clutch, the power delivery system comprising; a clutch for disconnecting the engagement between an output member of the fluid coupling and the output shaft when the dog clutch is operated in order to switch between an on-state and an off-state. The clutch includes a clutch plate case in the form of a hollow cylinder which is connected to the turbine shell. A clutch disk wheel connected to the output shaft. A first set of clutch plates supports the clutch plate case, and a second set of clutch plates supports the clutch disk wheel. The first and second sets of clutch plates are positioned within the case adjacent the radially inward periphery of the fluid coupling; the clutch is engaged when the first and second sets of clutch plates are selectively pressed; an oil pump for supplying oil into the fluid coupling case; and the oil pump positioned within the case adjacent the radially inward periphery of the clutch.

Moroto, S.; Sakakibara, S.

1987-06-16

244

TOPEX electrical power system  

NASA Technical Reports Server (NTRS)

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

1991-01-01

245

Robust tuning of power system stabilizers in multimachine power systems  

Microsoft Academic Search

This paper demonstrates the robust tuning of power systems stabilizers for power systems, operating at different loading conditions. A classical lead-lag power system stabilizer is used to demonstrate the technique. The problem of selecting the stabilizer parameters is converted to a simple optimization problem with an eigenvalue-based objective function, which is solved by a tabu search algorithm. The objective function

Y. L. Abdel-Magid; M. A. Abido; A. H. Mantaway

2000-01-01

246

Storage systems for tidal power  

Microsoft Academic Search

The effective use of tidal power by a typical electrical power system requires energy storage to retime the input to meet load demand. The cost of tidal power generation is relatively high and cannot be economically absorbed by the power system as secondary energy. Its constitution is more valuable when delivered at intermediate load factors. Traditional modes of \\

J. Warnock

1974-01-01

247

Power Systems Development Facility  

SciTech Connect

This report discusses Test Campaign TC12 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (SW) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). While operating as a gasifier, either air or oxygen can be used as the oxidant. Test run TC12 began on May 16, 2003, with the startup of the main air compressor and the lighting of the gasifier start-up burner. The Transport Gasifier operated until May 24, 2003, when a scheduled outage occurred to allow maintenance crews to install the fuel cell test unit and modify the gas clean-up system. On June 18, 2003, the test run resumed when operations relit the start-up burner, and testing continued until the scheduled end of the run on July 14, 2003. TC12 had a total of 733 hours using Powder River Basin (PRB) subbituminous coal. Over the course of the entire test run, gasifier temperatures varied between 1,675 and 1,850 F at pressures from 130 to 210 psig.

None

2003-07-01

248

Wind Energy System Time-domain (WEST) analyzers using hybrid simulation techniques  

NASA Technical Reports Server (NTRS)

Two stand-alone analyzers constructed for real time simulation of the complex dynamic characteristics of horizontal-axis wind energy systems are described. Mathematical models for an aeroelastic rotor, including nonlinear aerodynamic and elastic loads, are implemented with high speed digital and analog circuitry. Models for elastic supports, a power train, a control system, and a rotor gimbal system are also included. Limited correlation efforts show good comparisons between results produced by the analyzers and results produced by a large digital simulation. The digital simulation results correlate well with test data.

Hoffman, J. A.

1979-01-01

249

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

250

CURENT Course Power System Toolbox  

E-print Network

(Ontario Hydro and Cherry Tree Scientific Software) Power System Toolbox uses MATLAB code to perform (1CURENT Course Power System Toolbox Prof. Joe H. Chow Rensselaer Polytechnic Institute ECSE Department August 25, 2014 #12;Power System Toolbox Developers: Joe Chow, Kwok Cheung, and Graham Rogers

Mitchell, John E.

251

Power Systems Development Facility  

SciTech Connect

This report discusses Test Campaign TC15 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Power Generation, Inc. (SPG) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or gasifier using a particulate control device (PCD). While operating as a gasifier, either air or oxygen can be used as the oxidant. Test run TC15 began on April 19, 2004, with the startup of the main air compressor and the lighting of the gasifier startup burner. The Transport Gasifier was shutdown on April 29, 2004, accumulating 200 hours of operation using Powder River Basin (PRB) subbituminous coal. About 91 hours of the test run occurred during oxygen-blown operations. Another 6 hours of the test run was in enriched-air mode. The remainder of the test run, approximately 103 hours, took place during air-blown operations. The highest operating temperature in the gasifier mixing zone mostly varied from 1,800 to 1,850 F. The gasifier exit pressure ran between 200 and 230 psig during air-blown operations and between 110 and 150 psig in oxygen-enhanced air operations.

Southern Company Services

2004-04-30

252

Power flow for spacecraft power systems  

NASA Technical Reports Server (NTRS)

A method for constructing the generalized system-level admittance matrix for use with a Newton-Raphson power flow is presented. The network modeling technique presented does not use the standard pi-equivalent models, which assume a lossless return path, for the transmission line and transformer. If the return path cannot be assumed lossless, then the standard algorithms for constructing the system admittance matrix cannot be used. The method presented here uses concepts from linear graph theory to combine network modules to form the system-level admittance matrix. The modeling technique is presented, and the resulting matrix is used with a standard Newton-Raphson power flow to calculate all system voltages and current (power) flows.

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

1989-01-01

253

Development of a multiplane multispeed balancing system for turbine systems  

NASA Technical Reports Server (NTRS)

A prototype high speed balancing system was developed for assembled gas turbine engine modules. The system permits fully assembled gas turbine modules to be operated and balanced at selected speeds up to full turbine speed. The balancing system is a complete stand-alone system providing all necesary lubrication and support hardware for full speed operation. A variable speed motor provides the drive power. A drive belt and gearbox provide rotational speeds up to 21,000 rpm inside a vacuum chamber. The heart of the system is a dedicated minicomputer with attendant data acquisition, storage and I/O devices. The computer is programmed to be completely interactive with the operator. The system was installed at CCAD and evaluated by testing 20 T55 power turbines and 20 T53 power turbines. Engine test results verified the performance of the high speed balanced turbines.

Martin, M. R.

1984-01-01

254

Heat and Power Systems Design  

E-print Network

HEAT AND POWER SYSTEMS DESIGN H. D. Spriggs and J. V. Shah, Leesburg. VA ABSTRACT The selection of heat and power systems usually does not include a thorough analysis of the process heating. cooling and power requirements. In most cases..., these process requirements are accepted as specifications before heat and power systems are selected and designed. In t~is article we describe how Process Integration using Pinch Technology can be used to understand and achieve the minimum process heating...

Spriggs, H. D.; Shah, J. V.

255

Batteries and Power Systems  

NSDL National Science Digital Library

All About Circuits is a website that â??provides a series of online textbooks covering electricity and electronics.â? Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Batteries and Power Systems, is the eleventh chapter in Volume I â??Direct Current. A few of the topics covered in this chapter include: Battery construction, Battery ratings, Special-purpose batteries, and Electron activity in chemical reactions. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

256

Transient and steady-state performance of space power research engine with resistive/motor loads  

SciTech Connect

This paper describes the results of tests on the Space Power Research Engine (SPRE) developed as an advanced power convertor for space-based electrical power generation. The tests were performed at NASA Lewis Research Center LeRC, to evaluate the interaction and performance of a Free-Piston Stirling Engine/Linear Alternator (FPSE/LA) feeding into either a resistive or small induction motor load. The test results showed that the control system could maintain constant voltage and stable periodic operation over a wide range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical, fractional horse-power induction motor yielded large and, in some cases, deleterious voltage transients. The steady-state and transient test results demonstrated the need for more effective controls for FPSE/LAs in stand-alone power systems, and can be used to validate analysis codes.

Kankam, M.D. [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center; Rauch, J.S. [NYMA, Inc., Cleveland, OH (United States)

1996-12-31

257

Body powered thermoelectric systems  

E-print Network

Great interest exists for and progress has be made in the effective utilization of the human body as a possible power supply in hopes of powering such applications as sensors and continuously monitoring medical devices ...

Settaluri, Krishna Tej

2012-01-01

258

Potassium Rankine power system for space power  

NASA Astrophysics Data System (ADS)

A review of the proposed concepts for multimegawatt (MMW) power levels in Strategic Defense Initiative applications was completed. A trade study format was used to evaluate currently proposed MMW ALERT mode concepts to determine which of these concepts could best meet the program requirements for steady-state and burst MMW power levels in Category 2. The MMW program's evaluation criteria were applied to each concept to determine its relative ranking within each criteria category. These criteria included the system characteristics related to its safety, reliability, mass, volume/area, technical risk, costs, environmental exposure, and growth potential. Technical feasibility issues associated with the successful development of each concept was also identified. An overall system concept ranking was developed for the four concepts that appeared to best meet the Category 2 MMW program requirements. The in-core thermionic and potassium Rankine power system concepts received the highest relative rankings from this study. The AMTEC and CBC technologies were ranked as distant second and third candidates, respectively. Rocketdyne has selected the potassium Rankine power system concept for additional study based upon its superior growth potential over the in-core thermionic MMW concept.

Baumeister, E. B.; Determan, William R.

259

Pluto Express power system architecture  

SciTech Connect

The Pluto Express power system must answer the challenge of the next generation spacecraft by reducing its power, mass and volume envelopes. Technology developed by the New Millennium Program will enable the power system to meet the stringent requirements for the Pluto Express mission without exceeding the spacecraft mass and volume budgets. Traditionally, there has been an increasing trend of the percentage of mass of the power system electronics with respect to the total spacecraft mass. With all of the previous technology focus on high density digital packaging, the power system electronics have not been keeping pace forcing the spacecraft to absorb a relative increase in the power system mass. The increasing trend can be reversed by using mixed signal ASICs and high density multi-chip-module (MCM) packaging techniques validated by the New Millennium Program. As the size of the spacecraft shrinks, the power system electronics must become tightly integrated with the spacecraft loads. The power system architecture needs the flexibility to accommodate the specific load requirements without sacrificing the capability for growth or reduction as the spacecraft requirements change throughout the development. Modularity is a key requirement that will reduce the overall power system cost. Although the focus has been on shrinking the power system volume and mass, the efficiency and functionality cannot be ignored. Increased efficiency and functionality will only enhance the power systems capability to reduce spacecraft power requirements. The combination of the New Millennium packaging technologies with the Pluto Express power system architecture will produce a product with the capability to meet a wide range of mission profiles while reducing system development costs.

Carr, G.A. [California Inst. of Tech., Pasadena, CA (United States). Jet Propulsion Lab.

1996-12-31

260

Space Station Power System issues  

NASA Technical Reports Server (NTRS)

A number of attractive options are available for the Space Station Power System. These include a photovoltaic system or solar dynamic system for power generation, batteries or fuel cells for energy storage and ac or dc for power management and distribution. These options are being explored during the present preliminary design and definition phase of the Space Station Program. Final selections are presently targeted for January 1986.

Forestieri, A. F.

1985-01-01

261

Skylab technology electrical power system  

NASA Technical Reports Server (NTRS)

The solar array/battery power systems for the Skylab vehicle were designed to operate in a solar inertial pointing mode to provide power continuously to the Skylab. Questions of power management are considered, taking into account difficulties caused by the reduction in power system performance due to the effects of structural failure occurring during the launching process. The performance of the solar array of the Apollo Telescope Mount Power System is discussed along with the Orbital Workshop solar array performance and the Airlock Module power conditioning group performance. A list is presented of a number of items which have been identified during mission monitoring and are recommended for electrical power system concepts, designs, and operation for future spacecraft.

Woosley, A. P.; Smith, O. B.; Nassen, H. S.

1974-01-01

262

POWER SYSTEMS STABILITY WITH LARGE-SCALE WIND POWER PENETRATION  

E-print Network

generation which may lead to power system control problems. Therefore, adequate models of an Automatic Automatic Generation Control, Power Balancing, Power System Stability, Frequency Stability, and Wind Power 1 of an Automatic Generation Control (AGC) system, wind farms, conventional power plants and Combined Heat and Power

Bak-Jensen, Birgitte

263

Hydrothermal Power Systems  

NSDL National Science Digital Library

This web site by the Department of Energy (DOE) covers geothermal power plants by using text and diagrams. The website describes the three kinds of plants and provides photographs of each. The page also gives information on the future of geothermal energy and also provides links to geothermal power plants across the US.

2007-07-20

264

The space station power system  

NASA Technical Reports Server (NTRS)

The manned space station is the next major NASA program. It presents many challenges to the power system designers. The power system in turn is a major driver on the overall configuration. In this paper, the major requirements and guidelines that affect the station configuration and the power system are explained. The evolution of the space station power system from the NASA program development-feasibility phase through the current preliminary design phase is described. Several early station concepts, both fanciful and feasible, are described and linked to the present concept. The recently completed Phase B trade study selections of photovoltaic system technologies are described in detail. A summary of the present solar dynamic and power management and distribution systems is also given for completeness.

Baraona, C. R.

1986-01-01

265

Nanosatellite Power System Considerations  

NASA Technical Reports Server (NTRS)

The capability to build complex electronic functions into compact packages is opening the path to miniature satellites on the order of 1 kg mass, 10 cm across, packed with the computing processors, motion controllers, measurement sensors, and communications hardware necessary for operation. Power generation will be from short strings of silicon or gallium arsenide-based solar photovoltaic cells with the array power maximized by a peak power tracker (PPT). Energy storage will utilize a low voltage battery with nickel cadmium or lithium ion cells as the most likely selections for rechargeables and lithium (MnO2-Li) primary batteries for one shot short missions.

Robyn, M.; Thaller, L.; Scott, D.

1995-01-01

266

Electrical power systems for Mars  

NASA Technical Reports Server (NTRS)

Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

Giudici, Robert J.

1986-01-01

267

Electrical power systems for Mars  

NASA Astrophysics Data System (ADS)

Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.

Giudici, Robert J.

1986-05-01

268

Electrical power generation systems - Combat aircraft perspective  

NASA Astrophysics Data System (ADS)

The electrical power generation system requirements of combat aircraft are briefly examined. In particular, attention is given to customer requirements, development of the installed electrical power in aircraft, electrical load analysis for designing the power generation system, and definition of aircraft electrical power supply characteristics and consumer qualities. The discussion also covers reliability requirements for power generation systems, design of a power generation system, control and protection equipment in power generation systems, and helicopter electrical power systems.

Moeller, R.

269

Reactive power compensating system  

DOEpatents

The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

Williams, Timothy J. (Redondo Beach, CA); El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Seattle, WA)

1987-01-01

270

Reactive Power Compensating System.  

DOEpatents

The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.

Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

1985-01-04

271

Power transaction issues in deregulated power systems  

E-print Network

are the elements of the bus admittance matrix Y, ?, of the system. Where, the Y?, 's - the diagonal ennies ? are equal to the sum of the admittances of all lines and transformers connecting bus j to all other buses including the ground. And, the Y?. 's ? the off...-diagonal entries - are equal to the negatives of the admittances of lines between bus i and bus j. Yij's are equal to zero if bus i and bus j are not connected. Hence, we have (N-1) P-equations and NPQ Q-equations. The unknowns are Therefore, the power flow...

Roycourt, Henrik

2012-06-07

272

Space power systems technology  

NASA Technical Reports Server (NTRS)

Reported here is a series of studies which examine several potential catalysts and electrodes for some fuel cell systems, some materials for space applications, and mathematical modeling and performance predictions for some solid oxide fuel cells and electrolyzers. The fuel cell systems have a potential for terrestrial applications in addition to solar energy conversion in space applications. Catalysts and electrodes for phosphoric acid fuel cell systems and for polymer electrolyte membrane (PEM) fuel cell and electrolyzer systems were examined.

Coulman, George A.

1994-01-01

273

Power generation systems and methods  

NASA Technical Reports Server (NTRS)

A power generation system includes a plurality of submerged mechanical devices. Each device includes a pump that can be powered, in operation, by mechanical energy to output a pressurized output liquid flow in a conduit. Main output conduits are connected with the device conduits to combine pressurized output flows output from the submerged mechanical devices into a lower number of pressurized flows. These flows are delivered to a location remote of the submerged mechanical devices for power generation.

Jones, Jack A. (Inventor); Chao, Yi (Inventor)

2011-01-01

274

Power systems for future missions  

NASA Technical Reports Server (NTRS)

A comprehensive scenario of future missions was developed and applicability of different power technologies to these missions was assessed. Detailed technology development roadmaps for selected power technologies were generated. A simple methodology to evaluate economic benefits of current and future power system technologies by comparing Life Cycle Costs of potential missions was developed. The methodology was demonstrated by comparing Life Cycle Costs for different implementation strategies of DIPS/CBC technology to a selected set of missions.

Gill, S. P.; Frye, P. E.; Littman, Franklin D.; Meisl, C. J.

1994-01-01

275

Fault diagnosis of power systems  

SciTech Connect

Fault diagnosis of power systems plays a crucial role in power system monitoring and control that ensures stable supply of electrical power to consumers. In the case of multiple faults or incorrect operation of protective devices, fault diagnosis requires judgment of complex conditions at various levels. For this reason, research into application of knowledge-based systems go an early start and reports of such systems have appeared in may papers. In this paper, these systems are classified by the method of inference utilized in the knowledge-based systems for fault diagnosis of power systems. The characteristics of each class and corresponding issues as well as the state-of-the-art techniques for improving their performance are presented. Additional topics covered are user interfaces, interfaces with energy management systems (EMS's), and expert system development tools for fault diagnosis. Results and evaluation of actual operation in the field are also discussed. Knowledge-based fault diagnosis of power systems will continue to disseminate.

Sekine, Y. (Dept. of Electrical Engineering, Univ. of Tokyo, Tokyo 133 (JP)); Akimoto, Y. (Tokyo Electric Power Co., Tokyo 104 (JP)); Kunugi, M. (Toshiba Corp., Tokyo 183 (JP))

1992-05-01

276

Power turbine ventilation system  

NASA Technical Reports Server (NTRS)

Air control mechanism within a power turbine section of a gas turbine engine. The power turbine section includes a rotor and at least one variable pitch propulsor blade. The propulsor blade is coupled to and extends radially outwardly of the rotor. A first annular fairing is rotatable with the propulsor blade and interposed between the propulsor blade and the rotor. A second fairing is located longitudinally adjacent to the first fairing. The first fairing and the second fairing are differentially rotatable. The air control mechanism includes a platform fixedly coupled to a radially inner end of the propulsor blade. The platform is generally positioned in a first opening and a first fairing. The platform and the first fairing define an outer space. In a first position corresponding with a first propulsor blade pitch, the platform is substantially conformal with the first fairing. In a second position corresponding with the second propulsor blade pitch, an edge portion of the platform is displaced radially outwardly from the first fairing. When the blades are in the second position and rotating about the engine axis, the displacement of the edge portion with respect to the first fairing allows air to flow from the outer space to the annular cavity.

Wakeman, Thomas G. (Inventor); Brown, Richard W. (Inventor)

1991-01-01

277

Power enhanced frequency conversion system  

NASA Technical Reports Server (NTRS)

A frequency conversion system includes at least one source providing a first near-IR wavelength output including a gain medium for providing high power amplification, such as double clad fiber amplifier, a double clad fiber laser or a semiconductor tapered amplifier to enhance the power output level of the near-IR wavelength output. The NFM device may be a difference frequency mixing (DFM) device or an optical parametric oscillation (OPO) device. Pump powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Ra-man/Brillouin amplifier or oscillator between the high power source and the NFM device.

Sanders, Steven (Inventor); Lang, Robert J. (Inventor); Waarts, Robert G. (Inventor)

2001-01-01

278

The ac power system testbed  

NASA Technical Reports Server (NTRS)

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.

1987-01-01

279

Thruster models for NEP system analysis  

NASA Technical Reports Server (NTRS)

There are currently no thruster modeling codes that can be integrated with power system codes for full propulsion system modeling. Most existing thruster models were written from a 'stand alone' viewpoint, assuming the user is performing analyses on thruster performance alone. The goal of the present modeling effort is to develop thruster codes that model performance and scaling as a function of mission and system inputs, rather than in terms of more elemental physical parameters. System level parameters of interest are as follows: performance, such as specific impulse and efficency; terminal characteristics, such as voltage or current; and mass. Specific impulse and efficiency couple with mission analyses, while terminal characteristics allow integration with power systems. Additional information on lifetime and operation may be required for detailed designs.

Gilland, Jim

1993-01-01

280

The Ames Power Monitoring System  

NASA Technical Reports Server (NTRS)

The Ames Power Monitoring System (APMS) is a centralized system of power meters, computer hardware, and specialpurpose software that collects and stores electrical power data by various facilities at Ames Research Center (ARC). This system is needed because of the large and varying nature of the overall ARC power demand, which has been observed to range from 20 to 200 MW. Large portions of peak demand can be attributed to only three wind tunnels (60, 180, and 100 MW, respectively). The APMS helps ARC avoid or minimize costly demand charges by enabling wind-tunnel operators, test engineers, and the power manager to monitor total demand for center in real time. These persons receive the information they need to manage and schedule energy-intensive research in advance and to adjust loads in real time to ensure that the overall maximum allowable demand is not exceeded. The APMS (see figure) includes a server computer running the Windows NT operating system and can, in principle, include an unlimited number of power meters and client computers. As configured at the time of reporting the information for this article, the APMS includes more than 40 power meters monitoring all the major research facilities, plus 15 Windows-based client personal computers that display real-time and historical data to users via graphical user interfaces (GUIs). The power meters and client computers communicate with the server using Transmission Control Protocol/Internet Protocol (TCP/IP) on Ethernet networks, variously, through dedicated fiber-optic cables or through the pre-existing ARC local-area network (ARCLAN). The APMS has enabled ARC to achieve significant savings ($1.2 million in 2001) in the cost of power and electric energy by helping personnel to maintain total demand below monthly allowable levels, to manage the overall power factor to avoid low power factor penalties, and to use historical system data to identify opportunities for additional energy savings. The APMS also provides power engineers and electricians with the information they need to plan modifications in advance and perform day-to-day maintenance of the ARC electric-power distribution system.

Osetinsky, Leonid; Wang, David

2003-01-01

281

Analysis of Power System Dynamics Subject to Stochastic Power Injections  

E-print Network

1 Analysis of Power System Dynamics Subject to Stochastic Power Injections Sairaj V. Dhople, Member on power system dynamics with a focus on time scales involving electromechan- ical phenomena), while the power system dynamics are described by the standard differential algebraic equation (DAE

Liberzon, Daniel

282

Power management of multi-hundred kilowatt spacecraft power systems  

NASA Technical Reports Server (NTRS)

A NASA-sponsored study of space power distribution system technology is in progress to develop an Autonomously Managed Power System (AMPS) for large space power platforms. The conceptual design of a 250 kW photovoltaic power system, including the power management subsystem (PMS), is presented. A PMS concept is derived based on the need to accommodate the increased complexity of a utility-type power system, and to minimize Shuttle resupply and ground station operational costs. The main PMS functions are discussed along with the control strategies of the autonomously managed power system.

Decker, D. K.; Fleck, G. W.; Graves, J.

1981-01-01

283

Solar-Powered Refrigeration System  

NASA Astrophysics Data System (ADS)

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Ewert, Michael K.; Bergeron, David J., III

2002-10-01

284

Solar-Powered Refrigeration System  

NASA Technical Reports Server (NTRS)

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure. and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2001-01-01

285

Solar-Powered Refrigeration System  

NASA Technical Reports Server (NTRS)

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2002-01-01

286

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

287

The CMS Detector Power System  

E-print Network

The power system for the on-detector electronics of the CMS Experiment comprises approximately 12000 low voltage channels, with a total power requirement of 1.1 MVA. The radiation environment inside the CMS experimental cavern combined with an ambient magnetic field (reaching up to 1.3 kGauss at the detector periphery) severely limit the available choices of low voltage supplies, effectively ruling out the use of commercial off-the-shelf DC power supplies. Typical current requirements at the CMS detector front end range from 1A-30A per channel at voltages ranging between 1.25V and 8V. This requires in turn that the final stage of the low voltage power supply be located on the detector periphery. Power to the CMS front-end electronics is stabilized by a 2 MVA uninterruptible power supply (UPS) located in a CMS surface building. This UPS isolates the CMS detector from disturbances on the local power grid and provides for 2 minutes of autonomy following a power failure, allowing for an orderly shutdown of detect...

Lusin, S

2008-01-01

288

Impact of Power Generation Uncertainty on Power System Static Performance  

E-print Network

Impact of Power Generation Uncertainty on Power System Static Performance Yu Christine Chen, Xichen uncer- tainties on the generation side of power systems. We propose a method to assess whether static determined by the forecasted renewable power injection. In our methodology, the uncertainty in generation can

Liberzon, Daniel

289

DYNAMIC MODELLING OF AUTONOMOUS POWER SYSTEMS INCLUDING RENEWABLE POWER SOURCES.  

E-print Network

(thermal, gas, diesel) and renewable (hydro, wind) power units. The objective is to assess the impact system components are developed. Emphasis is given in the representation of different hydro power plantDYNAMIC MODELLING OF AUTONOMOUS POWER SYSTEMS INCLUDING RENEWABLE POWER SOURCES. ABSTRACT The use

Paris-Sud XI, Université de

290

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

291

A Nonlinear Digital Control Solution for a DC/DC Power Converter  

NASA Technical Reports Server (NTRS)

A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.

Zhu, Minshao

2002-01-01

292

Nanosat Intelligent Power System Development  

NASA Technical Reports Server (NTRS)

NASA Goddard Space Flight Center is developing a class of satellites called nano-satellites. The technologies developed for these satellites will enable a class of constellation missions for the NASA Space Science Sun-Earth Connections theme and will be of great benefit to other NASA enterprises. A major challenge for these missions is meeting significant scientific- objectives with limited onboard and ground-based resources. Total spacecraft power is limited by the small satellite size. Additionally, it is highly desirable to minimize operational costs by limiting the ground support required to manage the constellation. This paper will describe how these challenges are met in the design of the nanosat power system. We will address the factors considered and tradeoffs made in deriving the nanosat power system architecture. We will discuss how incorporating onboard fault detection and correction capability yields a robust spacecraft power bus without the mass and volume penalties incurred from redundant systems and describe how power system efficiency is maximized throughout the mission duration.

Johnson, Michael A.; Beaman, Robert G.; Mica, Joseph A.; Truszkowski, Walter F.; Rilee, Michael L.; Simm, David E.

1999-01-01

293

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

294

Power system dynamic load identification and stability  

Microsoft Academic Search

Proper power system load models are playing more important roles in power system stability analysis in today's stressed power systems. Different load models may cause a large difference in stability analytical results. Measurement based load modeling gives a closer look at the real power system loads and their dynamic characteristics. In this paper, genetic algorithms and evolutionary programming based system

S. Z. Zhu; Z. Y. Dong; K. P. Wong; Z. H. Wang

2000-01-01

295

Visualization of Power Systems Final Project Report  

E-print Network

Visualization of Power Systems Final Project Report Power Systems Engineering Research Center Systems Engineering Research Center Visualization of Power Systems Final Report Thomas J. Overbye, Project) the development and/or enhancement of techniques for visualizing power system data using two-dimensional (2D

296

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

297

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

298

Modeling of power electronic systems with EMTP  

NASA Technical Reports Server (NTRS)

In view of the potential impact of power electronics on power systems, there is need for a computer modeling/analysis tool to perform simulation studies on power systems with power electronic components as well as to educate engineering students about such systems. The modeling of the major power electronic components of the NASA Space Station Freedom Electric Power System is described along with ElectroMagnetic Transients Program (EMTP) and it is demonstrated that EMTP can serve as a very useful tool for teaching, design, analysis, and research in the area of power systems with power electronic components. EMTP modeling of power electronic circuits is described and simulation results are presented.

Tam, Kwa-Sur; Dravid, Narayan V.

1989-01-01

299

Accelerating the transformation of power systems  

E-print Network

Accelerating the transformation of power systems Ancillary Services Peer Exchange with India in power system transformation is an increasingly vital resource for national and subnational decision, the 21st Century Power Partnership regularly works with country partners to organize peer

300

Robotic monitoring of power systems  

Microsoft Academic Search

Monitoring of electric power systems in real time for reliability, aging status, and presence of incipient faults requires distributed and centralized processing of large amounts of data from distributed sensor networks. To solve this task, cohesive multidisciplinary efforts are needed from such fields as sensing, signal processing, control, communications, optimization theory, and, more recently, robotics. This review paper focuses on

Bing Jiang; Alexander Mamishev

2004-01-01

301

Bonneville, Power Administration Timing System  

NASA Technical Reports Server (NTRS)

Time is an integral part of the Bonneville Power Administration's (BPA) operational systems. Generation and power transfers are planned in advance. Utilities coordinate with each other by making these adjustments on a timed schedule. Price varies with demand, so billing is based on time. Outages for maintenance are scheduled to assure they do not interrupt reliable power delivery. Disturbance records are aligned with recorded timetags for analysis and comparison with related information. Advanced applications like traveling wave fault location and real-time phase measurement require continuous timing with high precision. Most of BPA is served by a Central Time System (CTS) at the Dittmer Control Center near Portland, OR. This system keeps time locally and supplies time to both the control center systems and field locations via a microwave signal. It is kept synchronized to national standard time and coordinated with interconnected utilities. It is the official BPA time. Powwer system control and operation is described, followed by a description of BPA timing systems including CTS, the Fault Location Acquisition Reporter, time dissemination, and phasor measurements. References are provided for further reading.

Martin, Kenneth E.

1996-01-01

302

Estimation of Unknown Large Power System Dynamics  

Microsoft Academic Search

Instead of approximating an unknown large power system in the neighboring area by an infinite bus of constant voltage and constant frequency, this paper models the large power system DYNAMICS as one large electric machine so that both the voltage and the frequency of the unknown power system bus may vary. For the parameter estimation, an unknown dynamic power system

Yao-nan Yu; M. A. El-Sharkawi; M. D. Wvong

1979-01-01

303

Accelerating the transformation of power systems  

E-print Network

Accelerating the transformation of power systems Introduction Flexibility of operation--the ability of a power system to respond to change in demand and supply--is a characteristic of all power systems. Flexibility is especially prized in twenty-first century power systems, with higher levels of grid

304

Agent Modeling for Integrated Power Systems  

E-print Network

implement a retail electricity market to encourage customer participation. Although valuable experience hasAgent Modeling for Integrated Power Systems Final Project Report Power Systems Engineering Research;Power Systems Engineering Research Center Agent Modeling for Integrated Power Systems Final Project

305

Computation of closest bifurcations in power systems  

SciTech Connect

Voltage collapse and blackout can occur in an electric power system when load powers vary so that the system loses stability in a saddle node bifurcation. This paper computes load powers at which bifurcation occurs and which are locally closest to given operating load powers. The distance in load power parameter space to this locally closest bifurcation is an index of voltage collapse and a minimum load power margin. The computations are illustrated for several power systems. Monte-Carlo optimization techniques are applied to obtain multiple minimum load power margins. The use of load power margin sensitivities to select system controls is discussed.

Alvarado, F.; Dobson, I.; Hu, Y. (Univ. of Wisconsin, Madison, WI (United States). Electrical Computer Engineering Dept.)

1994-05-01

306

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

307

Power-by-wire aircraft secondary power systems  

Microsoft Academic Search

This paper describes the secondary power sources available on a large transport aircraft that supply power for the aircraft operating and payload systems. The benefits expected from integrating all of the engine-based hydraulic and pneumatic power sources into the electrical system are identified in qualitative terms. The estimated capacity of an all-electric secondary power system for a tri-jet and a

L. J. Feiner

1993-01-01

308

Decoupling Load and Power System Dynamics to Improve System Stability  

Microsoft Academic Search

With the increasing use of constant power loads in power system, their influences on the stability of the system cannot be ignored. This paper introduces a power buffer configuration based on the boost converter topology. The power buffer functions to decouple the power system and the load under fault condition to mitigate the negative influence of the constant power on

X. Y. Wang; D. M. Vilathgamuwa; S. S. Choi

2005-01-01

309

Manned spacecraft electrical power systems  

NASA Technical Reports Server (NTRS)

A brief history of the development of electrical power systems from the earliest manned space flights illustrates a natural trend toward a 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. Significant challenges different from Space Shuttle, innovative concepts and ideas, and station growth considerations are discussed. The Phase B Advanced Development hardware program is summarized and a status of Phase B preliminary tradeoff studies is presented.

Simon, William E.; Nored, Donald L.

1987-01-01

310

Uninterruptible power supply cogeneration system  

SciTech Connect

A power system is described for providing an uninterruptible power supply comprising: a first generator means for supplying energy to a primary load; a second generator means connected to an electrical utility, the first and second generator means being connected by a common shaft, the first generator means being electrically isolated from the electrical utility; prime mover means connected to the common shaft, the prime mover means for supplying mechanical energy to the shaft; and controller means interposed electrically between the second generator means and the secondary external load, the controller means causing the second generator means to become disconnected from the secondary load upon interruptions in the secondary load.

Gottfried, C.F.

1987-08-11

311

Computation of closest bifurcations in power systems  

Microsoft Academic Search

Voltage collapse and blackout can occur in an electric power system when load powers vary so that the system loses stability in a saddle node bifurcation. This paper computes load powers at which bifurcation occurs and which are locally closest to given operating load powers. The distance in load power parameter space to this locally closest bifurcation is an index

Fernando Alvarado; Ian Dobson; Yi Hu

1994-01-01

312

Seismic reliability of electrical power transmission systems  

Microsoft Academic Search

The reliability of electric power transmission systems is important for the probabilistic safety assessment of nuclear power plants under a given earthquake loading as it relates to the loss of off site power to the nuclear power plants. Here, a comprehensive model to evaluate the seismic reliability of electric power transmission systems is presented. The model provides probabilistic assessments of

J. A. Pires; A. H.-S. Ang; R. Villaverde

1996-01-01

313

Uninterruptible power supply systems in NTT  

Microsoft Academic Search

A decentralized power system for an AC power system and a DC power system has been developed. In this system, the uninterruptible power supply (UPS) system is installed in telecommunications rooms, and is aimed at peripheral equipment in switching systems. This UPS system consists of 1 kVA add-on type inverter units, and has a maximum capacity of 5 kVA through

H. Yamashita

1990-01-01

314

Power management of hybrid photovoltaic - fuel cell power systems  

Microsoft Academic Search

Photovoltaic (PV) solar energy systems are widely used as an important alternative energy source. To overcome the problem of intermittent power generation, PV power systems may be integrated with other power sources. Fuel cells are an attractive option because of high efficiency, modularity and fuel flexibility; however, one main week point is their slow dynamics. On the other hand, current

Zhenhua Jiang

2006-01-01

315

Advanced Radioisotope Power Systems Segmented Thermoelectric Research  

NASA Technical Reports Server (NTRS)

Flight times are long; - Need power systems with >15 years life. Mass is at an absolute premium; - Need power systems with high specific power and scalability. 3 orders of magnitude reduction in solar irradiance from Earth to Pluto. Nuclear power sources preferable. The Overall objective is to develop low mass, high efficiency, low-cost Advanced Radioisotope Power System with double the Specific Power and Efficiency over state-of-the-art Radioisotope Thermoelectric Generators (RTGs).

Caillat, Thierry

2004-01-01

316

an electric power transmission system  

E-print Network

“Geomagnetically induced currents ” (GIC) in ground-based technological networks are a manifestation of space weather. GIC are a potential source of problems to the systems and therefore important in practice. GIC in a power system (or in principle in any other discretely-earthed system) can be calculated conveniently by using matrix equations presented earlier. Since temporal variations associated with GIC are slow compared to the 50/60 Hz frequency used in power transmission, a dc treatment is acceptable. An essential quantity in calculations of GIC in a power grid is the earthing impedance matrix, which is the transfer function coupling GIC flowing to (from) the Earth with the voltages between the earthing points, called nodes or (sub)stations, and a remote earth. The diagonal elements of the matrix equal the earthing resistances of the nodes whereas an off-diagonal element expresses how much GIC at one earthing point affects the voltage at another node. In GIC calculations, except for some special treatments of individual sites, the off-diagonal elements are usually neglected by saying simply that the earthing points (are assumed to) lie distantly enough. In this paper, we examine the effects of off-diagonal elements of the earthing impedance matrix, i.e. the effects of interactions between different stations, on GIC calculations in greater detail and more quantitatively than before. We consider a fictitious system that represents a high-voltage power grid and a simple “network ” consisting of two stations with a line connecting them. For both systems, the conclusion can be drawn that the off-diagonal elements do not play a major role

Risto Pirjola

2007-01-01

317

2004 NET SYSTEM POWER CALCULATION COMMISSIONREPORT  

E-print Network

Adam Pan, Terry Ewing Principal Author David Ashuckian Manager Electricity Analysis Office Terry O power by fuel type. 2 Public Utilities Code section 398.2 (c). #12;3 2004 Gross System Power Although "gross system power." The gross system power mix changes from year to year as generation resources

318

Multi-Mission Power Analysis Tool (MMPAT) Version 3  

NASA Technical Reports Server (NTRS)

The Multi-Mission Power Analysis Tool (MMPAT) simulates a spacecraft power subsystem including the power source (solar array and/or radioisotope thermoelectric generator), bus-voltage control, secondary battery (lithium-ion or nickel-hydrogen), thermostatic heaters, and power-consuming equipment. It handles multiple mission types including heliocentric orbiters, planetary orbiters, and surface operations. Being parametrically driven along with its user-programmable features can reduce or even eliminate any need for software modifications when configuring it for a particular spacecraft. It provides multiple levels of fidelity, thereby fulfilling the vast majority of a project s power simulation needs throughout the lifecycle. It can operate in a stand-alone mode with a graphical user interface, in batch mode, or as a library linked with other tools. This software can simulate all major aspects of a spacecraft power subsystem. It is parametrically driven to reduce or eliminate the need for a programmer. Added flexibility is provided through user-designed state models and table-driven parameters. MMPAT is designed to be used by a variety of users, such as power subsystem engineers for sizing power subsystem components; mission planners for adjusting mission scenarios using power profiles generated by the model; system engineers for performing system- level trade studies using the results of the model during the early design phases of a spacecraft; and operations personnel for high-fidelity modeling of the essential power aspect of the planning picture.

Wood, Eric G.; Chang, George W.; Chen, Fannie C.

2012-01-01

319

Fuel-cell powered uninterruptible power supply systems: Design considerations  

Microsoft Academic Search

A 1-kVA fuel cell powered, line-interactive uninterruptible power supply (UPS) system that employs modular (fuel cell and power converter) blocks is introduced. Two commercially available proton-exchange membrane fuel cell (25–39V, 500W) modules together with suitable dc–dc and dc–ac power electronic converter modules are employed. A supercapacitor module is also used to compensate for the instantaneous power fluctuations and to overcome

Woojin Choi; Jo. W. Howze; Prasad Enjeti

2006-01-01

320

Advanced secondary power system for transport aircraft  

NASA Technical Reports Server (NTRS)

A concept for an advanced aircraft power system was identified that uses 20-kHz, 440-V, sin-wave power distribution. This system was integrated with an electrically powered flight control system and with other aircraft systems requiring secondary power. The resulting all-electric secondary power configuration reduced the empty weight of a modern 200-passenger, twin-engine transport by 10 percent and the mission fuel by 9 percent.

Hoffman, A. C.; Hansen, I. G.; Beach, R. F.; Plencner, R. M.; Dengler, R. P.; Jefferies, K. S.; Frye, R. J.

1985-01-01

321

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

322

Device system and method for miniaturized radiation spectrometer  

NASA Technical Reports Server (NTRS)

A device/system for radiation sensing is configured to detect high and low LET radiation. The radiation sensing system may include a high LET detector and a low LET detector coupled to the high LET detector by a CPU, wherein the high LET detector and the low LET detector are assembled within a single unit. The device/system may also include a high LET and low LET detector that may be coupled together without an internal CPU. Overall, the device/system may be a stand-alone system and/or coupled to an external processing device. The device/system may also be approximately 6.times.6.times.2 cm.sup.3 in size, making it hand portable and may weigh less or equal to approximately ninety (90) grams, and operate on less than or approximately 0.25 watts of power.

Stassinopoulos, Epaminondas G. (Inventor)

2008-01-01

323

MEMS Rotary Engine Power System  

NASA Astrophysics Data System (ADS)

This work presents a project overview and recent research results for the MEMS Rotary Engine Power System project at the Berkeley Sensor & Actuator Center of the University of California at Berkeley. The research motivation for the project is the high specific energy density of hydrocarbon fuels. When compared with the energy density of batteries, hydrocarbon fuels may have as much as 20x more energy. However, the technical challenge is the conversion of hydrocarbon fuel to electricity in an efficient and clean micro engine. A 12.9 mm diameter Wankel engine will be shown that has already generated 4 Watts of power at 9300rpm. In addition, the 1mm and 2.4 mm Wankel engines that BSAC is developing for power generation at the microscale will be discussed. The project goal is to develop electrical power output of 90milliwatts from the 2.4 mm engine. Prototype engine components have already been fabricated and these will be described. The integrated generator design concept utilizes a nickel-iron alloy electroplated in the engine rotor poles, so that the engine rotor also serves as the generator rotor.

Fernandez-Pello, A. Carlos; Pisano, Albert P.; Fu, Kelvin; Walther, David C.; Knobloch, Aaron; Martinez, Fabian; Senesky, Matt; Stoldt, Conrad; Maboudian, Roya; Sanders, Seth; Liepmann, Dorian

324

Simulation and optimum design of hybrid solar-wind and solar-wind-diesel power generation systems  

NASA Astrophysics Data System (ADS)

Solar and wind energy systems are considered as promising power generating sources due to its availability and topological advantages in local power generations. However, a drawback, common to solar and wind options, is their unpredictable nature and dependence on weather changes, both of these energy systems would have to be oversized to make them completely reliable. Fortunately, the problems caused by variable nature of these resources can be partially overcome by integrating these two resources in a proper combination to form a hybrid system. However, with the increased complexity in comparison with single energy systems, optimum design of hybrid system becomes more complicated. In order to efficiently and economically utilize the renewable energy resources, one optimal sizing method is necessary. This thesis developed an optimal sizing method to find the global optimum configuration of stand-alone hybrid (both solar-wind and solar-wind-diesel) power generation systems. By using Genetic Algorithm (GA), the optimal sizing method was developed to calculate the system optimum configuration which offers to guarantee the lowest investment with full use of the PV array, wind turbine and battery bank. For the hybrid solar-wind system, the optimal sizing method is developed based on the Loss of Power Supply Probability (LPSP) and the Annualized Cost of System (ACS) concepts. The optimization procedure aims to find the configuration that yields the best compromise between the two considered objectives: LPSP and ACS. The decision variables, which need to be optimized in the optimization process, are the PV module capacity, wind turbine capacity, battery capacity, PV module slope angle and wind turbine installation height. For the hybrid solar-wind-diesel system, minimization of the system cost is achieved not only by selecting an appropriate system configuration, but also by finding a suitable control strategy (starting and stopping point) of the diesel generator. The optimal sizing method was developed to find the system optimum configuration and settings that can achieve the custom-required Renewable Energy Fraction (fRE) of the system with minimum Annualized Cost of System (ACS). Du to the need for optimum design of the hybrid systems, an analysis of local weather conditions (solar radiation and wind speed) was carried out for the potential installation site, and mathematical simulation of the hybrid systems' components was also carried out including PV array, wind turbine and battery bank. By statistically analyzing the long-term hourly solar and wind speed data, Hong Kong area is found to have favorite solar and wind power resources compared with other areas, which validates the practical applications in Hong Kong and Guangdong area. Simulation of PV array performance includes three main parts: modeling of the maximum power output of the PV array, calculation of the total solar radiation on any tilted surface with any orientations, and PV module temperature predictions. Five parameters are introduced to account for the complex dependence of PV array performance upon solar radiation intensities and PV module temperatures. The developed simulation model was validated by using the field-measured data from one existing building-integrated photovoltaic system (BIPV) in Hong Kong, and good simulation performance of the model was achieved. Lead-acid batteries used in hybrid systems operate under very specific conditions, which often cause difficulties to predict when energy will be extracted from or supplied to the battery. In this thesis, the lead-acid battery performance is simulated by three different characteristics: battery state of charge (SOC), battery floating charge voltage and the expected battery lifetime. Good agreements were found between the predicted values and the field-measured data of a hybrid solar-wind project. At last, one 19.8kW hybrid solar-wind power generation project, designed by the optimal sizing method and set up to supply power for a telecommunication relay station on a remote island of Guangdong pr

Zhou, Wei

325

Integration of Storage Devices into Power Systems  

E-print Network

Integration of Storage Devices into Power Systems with Renewable Energy Sources Final Project System #12;Integration of Storage Devices into Power Systems with Renewable Energy Sources Final Project of Storage Devices into Power Systems with Renewable Energy Sources" (project S-40). We express our

326

Artificial Intelligence and Spacecraft Power Systems  

NASA Technical Reports Server (NTRS)

This talk will present the work which has been done at NASA Marshall Space Flight Center involving the use of Artificial Intelligence to control the power system in a spacecraft. The presentation will include a brief history of power system automation, and some basic definitions of the types of artificial intelligence which have been investigated at MSFC for power system automation. A video tape of one of our autonomous power systems using co-operating expert systems, and advanced hardware will be presented.

Dugel-Whitehead, Norma R.

1997-01-01

327

Assessing the Usefulness of AIRS Radiance Observations in a 4D-Var Assimilation Scheme Using the Penn State/NCAR Mesoscale Model Version 5 (MM5) and a Stand Alone Radiative Transfer Algorithm (SARTA)  

NASA Technical Reports Server (NTRS)

Short-term precipitation forecast skill remains poor despite further advances in numerical modeling and data analysis. Utilizing indirect observations, such as the radiance observations obtained from the Atmospheric Infrared Sounder (AIRS), in a 4D-Var assimilation scheme may lead to a rapid improvement in the skill of 12-h QPF. In order to investigate the usefulness of AIRS observations, the adjoint code of a radiative transfer model (SARTA) is developed and linked to MM5 4D-Var system. A statistical comparison of the AIRS radiances with those calculated using the linked MMS-SARTA model is carried out to assess errors in the radiative transfer model, MM5 and AIRS data, and to develop a quality control scheme. Outliers and any bias that may exist in radiative transfer model, MM5 and AIRS data are identified. An adjoint sensitivity study, utilizing the SARTA adjoint model, is then done to identify the relative sensitivities of each spectral channel to such parameters as atmospheric temperature, pressure, and mixing ratio. Another sensitivity study is done using the MM5 alone to determine the sensitivity of the 12-h QPF to model parameters such as atmospheric temperature, pressure, and mixing ratio under various weather regimes (i.e. summertime convection, winter snowfall). Results from these two types of adjoint sensitivity studies are used to determine which AIRS channels contribute most to 12-h QPF under differing weather regimes. This information is useful when conducting 4D-Var experiments using a subset of the 2378 AIRS spectral channels. Finally, 4D-Var experiments are done to analyze the impact of the AIRS observations on the quality of the 12-h QPF results. This project falls under the data assimilation general session topic as specified by the conference organizers.

Carrier, M.; Zou, X.; Lapenta, W. M.; Jedlovec, G.

2004-01-01

328

Estimating the incidence, prevalence and true cost of asthma in the UK: secondary analysis of national stand-alone and linked databases in England, Northern Ireland, Scotland and Wales—a study protocol  

PubMed Central

Introduction Asthma is now one of the most common long-term conditions in the UK. It is therefore important to develop a comprehensive appreciation of the healthcare and societal costs in order to inform decisions on care provision and planning. We plan to build on our earlier estimates of national prevalence and costs from asthma by filling the data gaps previously identified in relation to healthcare and broadening the field of enquiry to include societal costs. This work will provide the first UK-wide estimates of the costs of asthma. In the context of asthma for the UK and its member countries (ie, England, Northern Ireland, Scotland and Wales), we seek to: (1) produce a detailed overview of estimates of incidence, prevalence and healthcare utilisation; (2) estimate health and societal costs; (3) identify any remaining information gaps and explore the feasibility of filling these and (4) provide insights into future research that has the potential to inform changes in policy leading to the provision of more cost-effective care. Methods and analysis Secondary analyses of data from national health surveys, primary care, prescribing, emergency care, hospital, mortality and administrative data sources will be undertaken to estimate prevalence, healthcare utilisation and outcomes from asthma. Data linkages and economic modelling will be undertaken in an attempt to populate data gaps and estimate costs. Separate prevalence and cost estimates will be calculated for each of the UK-member countries and these will then be aggregated to generate UK-wide estimates. Ethics and dissemination Approvals have been obtained from the NHS Scotland Information Services Division's Privacy Advisory Committee, the Secure Anonymised Information Linkage Collaboration Review System, the NHS South-East Scotland Research Ethics Service and The University of Edinburgh's Centre for Population Health Sciences Research Ethics Committee. We will produce a report for Asthma-UK, submit papers to peer-reviewed journals and construct an interactive map. PMID:25371419

Mukherjee, Mome; Gupta, Ramyani; Farr, Angela; Heaven, Martin; Stoddart, Andrew; Nwaru, Bright I; Fitzsimmons, Deborah; Chamberlain, George; Bandyopadhyay, Amrita; Fischbacher, Colin; Dibben, Christopher; Shields, Michael; Phillips, Ceri; Strachan, David; Davies, Gwyneth; McKinstry, Brian; Sheikh, Aziz

2014-01-01

329

Autonomous power system intelligent diagnosis and control  

NASA Technical Reports Server (NTRS)

The Autonomous Power System (APS) project at NASA Lewis Research Center is designed to demonstrate the abilities of integrated intelligent diagnosis, control, and scheduling techniques to space power distribution hardware. Knowledge-based software provides a robust method of control for highly complex space-based power systems that conventional methods do not allow. The project consists of three elements: the Autonomous Power Expert System (APEX) for fault diagnosis and control, the Autonomous Intelligent Power Scheduler (AIPS) to determine system configuration, and power hardware (Brassboard) to simulate a space based power system. The operation of the Autonomous Power System as a whole is described and the responsibilities of the three elements - APEX, AIPS, and Brassboard - are characterized. A discussion of the methodologies used in each element is provided. Future plans are discussed for the growth of the Autonomous Power System.

Ringer, Mark J.; Quinn, Todd M.; Merolla, Anthony

1991-01-01

330

The design of the NEPTUNE power system  

Microsoft Academic Search

The proposed NEPTUNE observatory will include about 30 locations on the Juan de Fuca plate where scientific instruments can be connected for communication and power. The NEPTUNE power system is required to make available at each location the largest amount of power possible, using conventional submarine telecommunications cable. The power delivery system is based on the use of a standard

Harold Kirkham; Bruce M. Howeb; Vatché Vorpérian; Paul Bowerman

2001-01-01

331

Cask system maintenance in the Federal Waste Management System  

Microsoft Academic Search

In early 1988, in support of the development of the transportation system for the Office of Civilian Radioactive Waste Management System (OCRWM), a feasibility study was undertaken to define a the concept for a stand-alone, green-field'' facility for maintaining the Federal Waste Management System (FWMS) casks. This study provided and initial layout facility design, an estimate of the construction costs,

R. B. Pope; M. J. Rennich; L. G. Medley; C. R. Attaway

1991-01-01

332

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

333

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

334

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

335

Photovoltaic power without batteries for continuous cathodic protection and an alternate photovoltaic/ultracapacitor combined power source  

SciTech Connect

The Coastal Systems Station (COASTSYSTA) designed, installed, and started up on 20 January 1990, a state-of-the-art stand-alone photovoltaic powered impressed current cathodic protection system (PVCPSYS) not requiring any backup power for steel and iron submerged structures. The PVCPSYS, installed on a 775-foot steel sheet piling of a Navy dock bulkhead, provides complete, continuous corrosion protection. The PVCPSYS has been in operation for more than five years, has not required any repair or maintenance, and is environmentally clean. Initial cost savings of the PVCPSYS versus conventional cathodic protection system was $46,000. A second PVCPSYS was installed on another 800-foot bulkhead on 21 May 1993. It is also providing complete corrosion protection without backup power. Performance is well documented. Other potential applications are moth-balled ships, locks, dams, bridges, pipelines, and similar structures. These systems are considered a major advance by Sandia and the Department of Defense (DOD) Photovoltaic Review Committee. An ultracapacitor, a recent hi-tech development that is environmentally clean, will be incorporated in the PVCPSYS when required to enhance the system`s capability. A photovoltaic/ultracapacitor (or equivalent) combined power source operating under adverse conditions, and/or to satisfy or meet regulations will assure cathodic protection, including pipelines carrying combustibles or other products that could otherwise create environmental problems. Patents are pending on this PVCPSYS and the photovoltaic/ ultracapacitor powered systems.

Muehl, W.W. Sr. [Coastal Systems Station, Panama City, FL (United States). Dahlgren Div.

1995-12-31

336

TESTING THE STAND-ALONE MICROBEAM AT COLUMBIA UNIVERSITY  

E-print Network

single-cell/single- particle (proton/Helium) microbeam irradiator, based on a recently installed 6 MV the beam diameter and increase the range of radiation fields available, intensive development work is being source(2) for generating higher LET beams and on a proton induced soft X ray microbeam(3) . During

337

Field Testing Stand-Alone Courseware: A Proven Practical Procedure.  

ERIC Educational Resources Information Center

Describes procedure to measure a new course's ability to meet standards in three areas: student acceptance, student gains, and student comprehension. It has been used over three years to test the acceptability of 31 courses which contain more than 200 videotape presentations, and thousands of pages of print materials. (Author/JEG)

Westgaard, Odin

1979-01-01

338

Laser power conversion system analysis, volume 1  

NASA Technical Reports Server (NTRS)

The orbit-to-orbit laser energy conversion system analysis established a mission model of satellites with various orbital parameters and average electrical power requirements ranging from 1 to 300 kW. The system analysis evaluated various conversion techniques, power system deployment parameters, power system electrical supplies and other critical supplies and other critical subsystems relative to various combinations of the mission model. The analysis show that the laser power system would not be competitive with current satellite power systems from weight, cost and development risk standpoints.

Jones, W. S.; Morgan, L. L.; Forsyth, J. B.; Skratt, J. P.

1979-01-01

339

SNS EXTRACTION FAST KICKER PULSED POWER SYSTEM  

Microsoft Academic Search

The Spallation Neutron Source (SNS) is a next generation high intensity beam facility. The extraction kicker system is a high peak power, high average power, high precision pulse-waveform, low beam impedance, and high repetition rate pulsed power system. It has been successfully design and developed at Brookhaven National Laboratory. The system consists of fourteen extraction magnet sections inside the ring

W. Zhang; J. Sandberg; H. Hahn; C. Pai; Y. Tan; N. Tsoupas; J. Tuozzolo; D. Warburton; J. Wei; K. Rust; R. Cutler

2004-01-01

340

X2000 power system electronics development  

NASA Technical Reports Server (NTRS)

The X2000 Power System Electronics (PSE) is a Jet Propulsion Laboratory (JPL) task to develop a new generation of power system building blocks for potential use on future deep space missions. The effort includes the development of electronic components and modules that can be used as building blocks in the design of generic spacecraft power systems.

Carr, Greg; Deligiannis, Frank; Franco, Lauro; Jones, Loren; Lam, Barbara; Nelson, Ron; Pantaleon, Jose; Ruiz, Ian; Treichler, John; Wester, Gene; Sauers, Jim; Giampoli, Paul; Haskell, Russ; Mulvey, Jim; Repp, John

2005-01-01

341

Nova pulse power system description and status  

SciTech Connect

The Nova laser system is designed to produce critical data in the nation's inertial confinement fusion effort. It is the world's largest peak power laser and presents various unique pulse power problems. In this paper, pulse power systems for this laser are described, the evolutionary points from prior systems are pointed out, and the current status of the hardware is given.

Holloway, R.W.; Whitham, K.; Merritt, B.T.; Gritton, D.G.; Oicles, J.A.

1981-06-01

342

Automated load management for spacecraft power systems  

NASA Technical Reports Server (NTRS)

An account is given of the results of a study undertaken by NASA's Marshall Space Flight Center to design and implement the load management techniques for autonomous spacecraft power systems, such as the Autonomously Managed Power System Test Facility. Attention is given to four load-management criteria, which encompass power bus balancing on multichannel power systems, energy balancing in such systems, power quality matching of loads to buses, and contingency load shedding/adding. Full implementation of these criteria calls for the addition of a second power channel.

Lollar, Louis F.

1987-01-01

343

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

344

G*Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences  

Microsoft Academic Search

G*Power (Erdfelder, Faul, & Buchner, 1996) was designed as a general stand-alone power analysis program for statistical tests\\u000a commonly used in social and behavioral research. G*Power 3 is a major extension of, and improvement over, the previous versions.\\u000a It runs on widely used computer platforms (i.e., Windows XP, Windows Vista, and Mac OS X 10.4) and covers many different statistical

Franz Faul; Edgar Erdfelder; Albert-Georg Lang; Axel Buchner

2007-01-01

345

Next generation cooled long range thermal sights with minimum size, weight, and power  

NASA Astrophysics Data System (ADS)

Situational awareness and precise targeting at day, night and severe weather conditions are key elements for mission success in asymmetric warfare. To support these capabilities for the dismounted soldier, AIM has developed a family of stand-alone thermal weapon sights based on high performance cooled IR-modules which are used e.g. in the infantryman of the future program of the German army (IdZ). The design driver for these sights is a long ID range <1500m for the NATO standard target to cover the operational range of a platoon with the engagement range of .50 cal rifles, 40mm AGLs or for reconnaissance tasks. The most recent sight WBZG has just entered into serial production for the IdZ enhanced system of the German army with additional capabilities like a wireless data link to the soldier backbone computer. Minimum size, weight and power (SWaP) are most critical requirements for the dismounted soldiers' equipment and sometimes push a decision towards uncooled equipment with marginal performance referring to the outstanding challenges in current asymmetric warfare, e.g. the capability to distinguish between combatants and non-combatants in adequate ranges. To provide the uncompromised e/o performance with SWaP parameters close to uncooled, AIM has developed a new thermal weapon sight based on high operating temperature (HOT) MCT MWIR FPAs together with a new low power single piston stirling cooler. In basic operation the sight is used as a clip-on in front of the rifle scope. An additional eyepiece for stand-alone targeting with e.g. AGLs or a biocular version for relaxed surveillance will be available. The paper will present details of the technologies applied for such long range cooled sights with size, weight and power close to uncooled.

Breiter, R.; Ihle, T.; Wendler, J.; Rühlich, I.; Ziegler, J.

2013-06-01

346

Power Systems Frequency Dynamic Monitoring System Design and Applications  

E-print Network

Power Systems Frequency Dynamic Monitoring System Design and Applications By Zhian Zhong Shedding Copyright © 2005, Zhian Zhong #12;Power Systems Frequency Dynamic Monitoring System Design dynamics is one of the most important parameters of an electrical power system. In order to understand

Schrijver, Karel

347

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

348

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

349

Power Control Algorithms for Satellite Communication Systems  

Microsoft Academic Search

Three different ground terminal transmit power control concepts for a Satcom system are examined. The effectiveness of constant satellite power (CSP) sharing among the carriers and adaptive satellite power (ASP) sharing is compared with constant ground terminal transmit power (CTP). It is shown that ASP offers substantial advantages over CSP in combating environmental degradations and that both can increase link

A. Ince; D. Brown; J. Midgley

1976-01-01

350

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

351

Visualization of an electric power transmission system  

Microsoft Academic Search

Visualization techniques are applied to an electric power system transmission network to create a graphical picture of network power flows and voltages. A geographic data map is used. Apparent power flow is encoded as the width of an arrow, with direction from real power flow. Flows are superposed on flow limits. Contour plots and color coding failed for representing bus

P. M. Mahadev; R. D. Christie

1994-01-01

352

Power electronics in wind energy conversion systems  

Microsoft Academic Search

This paper presents a brief review of the power electronics techniques used in wind energy conversion systems. Utilization of power electronics converters enables conversion of the generated power from any form to another and thus control the operation quality and obtain capture optimization. Attention is paid to power converters selection and design to satisfy good matching between generator type and

FAEKA M. H. KHATER

1996-01-01

353

POWER GRID DYNAMICS: ENHANCING POWER SYSTEM OPERATION THROUGH PRONY ANALYSIS  

SciTech Connect

Prony Analysis is a technique used to decompose a signal into a series consisting of weighted complex exponentials and promises to be an effi cient way of recognizing sensitive lines during faults in power systems such as the U.S. Power grid. Positive Sequence Load Flow (PSLF) was used to simulate the performance of a simple two-area-four-generator system and the reaction of the system during a line fault. The Dynamic System Identifi cation (DSI) Toolbox was used to perform Prony analysis and use modal information to identify key transmission lines for power fl ow adjustment to improve system damping. The success of the application of Prony analysis methods to the data obtained from PSLF is reported, and the key transmission line for adjustment is identifi ed. Future work will focus on larger systems and improving the current algorithms to deal with networks such as large portions of the Western Electricity Coordinating Council (WECC) power grid.

Ray, C.; Huang, Z.

2007-01-01

354

Tuning of power system stabilizers via genetic algorithm for stabilization of power system  

Microsoft Academic Search

The paper considers simultaneous placement and tuning of power system stabilizers for stabilization of power systems over a wide range of operating conditions using genetic algorithm. The power system operating at various conditions is considered as a finite set of plants. The problem of setting parameters of power system stabilizers is converted as a simple optimization problem that is solved

Mehran Rashidi; Farzan Rashidi; H. Monavar

2003-01-01

355

Grid-Tied Photovoltaic Power System  

NASA Technical Reports Server (NTRS)

A grid-tied photovoltaic (PV) power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. Operating costs of a PV power system are low compared to conventional power technologies. This method can displace the highest-cost electricity during times of peak demand in most climatic regions, and thus reduce grid loading. Net metering is often used, in which independent power producers such as PV power systems are connected to the utility grid via the customers main service panels and meters. When the PV power system is generating more power than required at that location, the excess power is provided to the utility grid. The customer pays the net of the power purchased when the on-site power demand is greater than the onsite power production, and the excess power is returned to the utility grid. Power generated by the PV system reduces utility demand, and the surplus power aids the community. Modern PV panels are readily available, reliable, efficient, and economical, with a life expectancy of at least 25 years. Modern electronics have been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy equal to the modern PV panels. The grid-tied PV power system was successfully designed and developed, and this served to validate the basic principles developed, and the theoretical work that was performed. Grid-tied PV power systems are reliable, maintenance- free, long-life power systems, and are of significant value to NASA and the community. Of particular value are the analytical tools and capabilities that have been successfully developed. Performance predictions can be made confidently for grid-tied PV systems of various scales. The work was done under the NASA Hybrid Power Management (HPM) Program, which is the integration of diverse power devices in an optimal configuration for space and terrestrial applications.

Eichenberg, Dennis J.

2011-01-01

356

Power quality improvement and uninterruptible power supply using a power conditioning system with energy storage capability  

Microsoft Academic Search

A power conditioning system with energy storage capability is proposed as a viable solution for improving the quality and the reliability of the electric energy supply. Several tasks can be performed at the same time, such as reactive power compensation, current harmonic reduction, and smoothing of pulsating loads. Moreover, the power conditioning system can operate as an uninterruptible power supply

D. Casadei; G. Grandi; G. Serra; C. Rossi

2005-01-01

357

The ITER Power And Particle Control System  

Microsoft Academic Search

The ITER power and particle control system is designed to exhaust the 300 to 400 MW of alpha and auxiliary heating power and the He ash created by the fusion reactions, to control the density, and to fuel the plasma. The power and particle control system consists of a single null poloidal divertor, a set of active pumps with a

D. Post; T. Ando; A. Antipenkov; S. Chiocchio; J. Dietz; G. Federici; M. Gouge; Y. Igitkhanov; G. Janeschitz; C. Karney; A. Kukushkin; P. Ladd; J. Mandrekas; E. Martin; D. Mitin; H. Nakamura; H. Pacher; R. Parker; W. Stacey; M. Sugihara; R. Tivey

1996-01-01

358

A power system for a microsatellite  

Microsoft Academic Search

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

Dan Olsson

1993-01-01

359

PV powering a weather station for severe weather  

SciTech Connect

A natural disaster, such as Hurricane Andrew, destroys thousands of homes and businesses. The destruction from this storm left thousands of people without communications, potable water, and electrical power. This prompted the Florida Solar Energy Center to study the application of solar electric power for use in disasters. During this same period, volunteers at the Tropical Prediction Center at the National Hurricane Center (NHC), Miami, Florida and the Miami Office of the National Weather Service (NWS) were working to increase the quantity and quality of observations received from home weather stations. Forecasters at NHC have found surface reports from home weather stations a valuable tool in determining the size, strength and course of hurricanes. Home weather stations appear able to record the required information with an adequate level of accuracy. Amateur radio, utilizing the Automatic Packet Report System, (APRS) can be used to transmit this data to weather service offices in virtually real time. Many weather data collecting stations are at remote sites which are not readily serviced by dependable commercial power. Photovoltaic (solar electric) modules generate electricity and when connected to a battery can operate as a stand alone power system. The integration of these components provides an inexpensive standalone system. The system is easy to install, operates automatically and has good communication capabilities. This paper discusses the design criteria, operation, construction and deployment of a prototype solar powered weather station.

Young, W. Jr. [Florida Solar Energy Center, Cocoa, FL (United States); Schmidt, J. [Joe Schmidt, Inc., Miami, FL (United States)

1997-12-31

360

Modular Solar Electric Power (MSEP) Systems (Presentation)  

SciTech Connect

This presentation discusses the development and deployment of Modular Solar Electric Power (MSEP) systems, the feasibility of application of existing binary power cycles to solar trough technology, and identification of next action items.

Hassani, V.

2000-06-18

361

Power system with an integrated lubrication circuit  

DOEpatents

A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

Hoff, Brian D. (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL); Algrain, Marcelo C. (Peoria, IL); Johnson, Kris W. (Washington, IL); Lane, William H. (Chillicothe, IL)

2009-11-10

362

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

363

dc side active power filters for aircraft electric power systems  

Microsoft Academic Search

A dc side active filter for a 400 Hz aircraft electric power system is proposed. The filter provides continuous adjustable reactive power, has fast response and high efficiency, and does not necessitate excess capacitive kVA required to supply highly unbalanced or nonlinear loads.

P. Enjeti; S. Kim

1992-01-01

364

Photovoltaic power without batteries for continuous cathodic protection and an alternate photovoltaic/ultracapacitor combined power source  

SciTech Connect

The Coastal Systems Station (COASTSYSTA) designed, installed, and started up on 20 January 1990, a state-of-the-art stand-alone photovoltaic powered impressed current cathodic protection system (PVCPSYS) not requiring any backup power for steel and iron submerged structures. The PVCPSYS, installed on a 775-foot steel sheet piling of a Navy dock bulkhead, provides complete, continuous corrosion protection. The PVCPSYS has been in operation for more than five years, has not required any repair or maintenance, ad is environmentally clean. Initial cost savings of the PVCPSYS versus conventional cathodic protection system was $46,000. A second PVCPSYS was installed on another 800-foot bulkhead on 21 May 1993. It is also providing complete corrosion protection without backup power. Performance is well documented. Other potential applications are moth-balled ships, locks, dams, bridges, pipelines, and similar structures. These systems are considered a major advance by Sandia and the Department of Defense (DOD) Photovoltaic Review Committee. An ultra-capacitor, a recent hi-tech development that is environmentally clean, will be incorporated in the PVCPSYS when required to enhance the system`s capability. A photovoltaic/ultracapacitor (or equivalent) combined power source operating under adverse conditions, and/or to satisfy or meet regulations will assure cathodic protection, including pipelines carrying combustibles or other products that could otherwise create environmental problems.

Muehl, W.W. [Dept. of the Navy, Panama City, FL (United States)

1994-12-31

365

Electric power distribution and load transfer system  

NASA Technical Reports Server (NTRS)

A power distribution system includes a plurality of power sources and load transfer units including transistors and diodes connected in series and leading to a common power output, each of the transistors being controller switchable subject to voltage levels of the respective input and output sides of said transistors, and the voltage and current level of said common power output. The system is part of an interconnection scheme in which all but one of the power sources is connected to a single load transfer unit, enabling the survival of at least a single power source with the failure of one of the load transfer units.

Bradford, Michael P. (Inventor); Parkinson, Gerald W. (Inventor); Grant, Ross M. (Inventor)

1987-01-01

366

Electric power distribution and load transfer system  

NASA Technical Reports Server (NTRS)

A power distribution system includes a plurality of power sources and load transfer units including transistors and diodes connected in series and leading to a common power output, each of the transistors being controller switchable subject to voltage levels of the respective input and output sides of said transistors, and the voltage and current level of said common power output. The system is part of an interconnection scheme in which all but one of the power sources is connected to a single load transfer unit, enabling the survival of at least a single power source with the failure of one of the load transfer units.

Bradford, Michael P. (Inventor); Parkinson, Gerald W. (Inventor); Grant, Ross M. (Inventor)

1989-01-01

367

Power Coupling Alternatives for the NEP Thermionic Power System  

NASA Technical Reports Server (NTRS)

Three output power coupling methods which can eliminate the high temperature insulator from the Nuclear Electric Propulsion (NEP) power system are described and estimates of their effects on the NEP system masses and cooling requirements are presented. Nominal 400 kWe power systems using push-pull and flux reset inductive output coupling are shown to have specific masses of 22.2 kg/kWe and 18.8 kg/kWe, respectively. Series connected heat pipe systems, which use the heat pipe-to-heat pipe resistance to isolate converters on adjacent heat pipes, are shown to have specific masses 0.5 to 1.4 kg/kWe lower than the NEP baseline system. Increasing the number and temperature of the heat pipes in the system without changing the electric output reduces the calculated system specific mass only slightly, whereas increasing the output power significantly reduces the specific mass. Estimates of cooling requirements indicate that 11-45 sq m of power conditioning radiator are needed. A possible location for the power conditioning radiator may be in the present location of the kapton sputter shield.

Manda, M. L.; Britt, E. J.; Fitzpatrick, G. O.

1978-01-01

368

Dynamic Reactive Power Control of Isolated Power Systems  

E-print Network

power systems. The problem is tackled using a Model Predictive Control (MPC) method, which uses a simplified model of the system to predict the voltage behavior of the system in future. The MPC method minimizes the voltage deviation of the predicted bus...

Falahi, Milad

2012-10-03

369

Multilevel automatic control system for frequency and power overcurrents in the USSR unified electric power system  

Microsoft Academic Search

Operational control of electric power systems is an important and complex task. A computer-based system for the automatic control of frequency and active power overcurrent permits greater loads to be carried on the system. At the same time, stability of parallel operations of the power system is increased. The weakest component of the system is the computer and the telemetry-remote

A. N. Komarov; A. I. Maksimov; S. A. Sovalov; G. A. Chernya; E. I. Anisimova; A. F. Arbuzov; I. V. Gostev; Yu. I. Popov; Kh. Segura

1983-01-01

370

Technologies for Lunar Surface Power Systems Power Beaming and Transfer  

NASA Astrophysics Data System (ADS)

Wireless power transmission within a given working area is required or enabling for many NASA Exploration Systems. Fields of application include robotics, habitats, autonomous rendezvous and docking, life support, EVA, and many others. In robotics applications, for example, the robots must move in the working area without being hampered by power cables and, meanwhile, obtain a continuous and constant power from a power transmitter. The development of modern technology for transmitting electric power over free space has been studied for several decades, but its use in a system has been mainly limited to low power, 1-2 Vdc output voltage at a transmission distance of few meters for which relatively less than 0.5 mW/cm2 is required (e.g., Radio frequency identification RFID). Most of the rectenna conversion efficiency research to date has concentrated in low GHz frequency range of 2.45 to 10 GHz, with some work at 35 GHz. However, for space application, atmospheric adsorbtion is irrelevant and higher frequency systems with smaller transmit and receive apertures may be appropriate. For high power, most of the work on rectennas has concentrated on optimizing the conversion efficiency of the microwave rectifier element; the highest power demonstrated was 35 kW of power over a distance of 1.5 km. The objective of this paper is to establish the manner in which a very large number of very low power microwave devices can be synchronized to provide a beam of microwaves that can be used to efficiently and safely transport a significant amount of power to a remote location where it can be converted to dc (or ac) power by a ``rectenna.'' The proposed system is based on spatial power combining of the outputs of a large number of devices synchronized by mutual injection locking. We have demonstrated at JPL that such power could be achieved by combining 25 sources in a configuration that allows for convenient steering of the resulting beam of microwaves. Retrodirective beam steering for microwave power transmission (the ability to accurately track a moving receiver) has been demonstrated at Texas A&M. It is proposed that the next step in development of this concept is a modest scale up from 25 elements to 435 followed by a further scale up using such 435 element arrays as subarrays for a still larger retrodirective system. Ultimately, transmit antenna sizes on the order of 100 meters are envisioned permitting transfer levels on the order of 30 kW to aerial vehicles up to 20 km.

Marzwell, Neville; Pogorzelski, Ronald J.; Chang, Kai; Little, Frank

2008-01-01

371

Direct FuelCell/Turbine Power Plant  

SciTech Connect

This report includes the progress in development of Direct Fuel Cell/Turbine. (DFC/T.) power plants for generation of clean power at very high efficiencies. The DFC/T power system is based on an indirectly heated gas turbine to supplement fuel cell generated power. The DFC/T power generation concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, 60% on coal gas, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, reduced carbon dioxide release to the environment, and potential cost competitiveness with existing combined cycle power plants. FCE successfully completed testing of the pre-alpha sub-MW DFC/T power plant. This power plant was constructed by integration of a 250kW fuel cell stack and a microturbine. Following these proof-of-concept tests, a stand-alone test of the microturbine verified the turbine power output expectations at an elevated (representative of the packaged unit condition) turbine inlet temperature. Preliminary design of the packaged sub-MW alpha DFC/T unit has been completed and procurement activity has been initiated. The preliminary design of a 40 MW power plant including the key equipment layout and the site plan was completed. A preliminary cost estimate for the 40 MW DFC/T plant has also been prepared. The tests of the cascaded fuel cell concept for achieving high fuel utilizations were completed. The tests demonstrated that the concept results in higher power plant efficiency. Alternate stack flow geometries for increased power output/fuel utilization capabilities are also being evaluated.

Hossein Ghezel-Ayagh

2004-11-19

372

Smart Power Supply for Battery-Powered Systems  

NASA Technical Reports Server (NTRS)

A power supply for battery-powered systems has been designed with an embedded controller that is capable of monitoring and maintaining batteries, charging hardware, while maintaining output power. The power supply is primarily designed for rovers and other remote science and engineering vehicles, but it can be used in any battery alone, or battery and charging source applications. The supply can function autonomously, or can be connected to a host processor through a serial communications link. It can be programmed a priori or on the fly to return current and voltage readings to a host. It has two output power busses: a constant 24-V direct current nominal bus, and a programmable bus for output from approximately 24 up to approximately 50 V. The programmable bus voltage level, and its output power limit, can be changed on the fly as well. The power supply also offers options to reduce the programmable bus to 24 V when the set power limit is reached, limiting output power in the case of a system fault detected in the system. The smart power supply is based on an embedded 8051-type single-chip microcontroller. This choice was made in that a credible progression to flight (radiation hard, high reliability) can be assumed as many 8051 processors or gate arrays capable of accepting 8051-type core presently exist and will continue to do so for some time. To solve the problem of centralized control, this innovation moves an embedded microcontroller to the power supply and assigns it the task of overseeing the operation and charging of the power supply assets. This embedded processor is connected to the application central processor via a serial data link such that the central processor can request updates of various parameters within the supply, such as battery current, bus voltage, remaining power in battery estimations, etc. This supply has a direct connection to the battery bus for common (quiescent) power application. Because components from multiple vendors may have differing power needs, this supply also has a secondary power bus, which can be programmed a priori or on-the-fly to boost the primary battery voltage level from 24 to 50 V to accommodate various loads as they are brought on line. Through voltage and current monitoring, the device can also shield the charging source from overloads, keep it within safe operating modes, and can meter available power to the application and maintain safe operations.

Krasowski, Michael J.; Greer, Lawrence; Prokop, Norman F.; Flatico, Joseph M.

2010-01-01

373

Artificial intelligence and space power systems automation  

NASA Technical Reports Server (NTRS)

Various applications of artificial intelligence to space electrical power systems are discussed. An overview is given of completed, on-going, and planned knowledge-based system activities. These applications include the Nickel-Cadmium Battery Expert System (NICBES) (the expert system interfaced with the Hubble Space Telescope electrical power system test bed); the early work with the Space Station Experiment Scheduler (SSES); the three expert systems under development in the space station advanced development effort in the core module power management and distribution system test bed; planned cooperation of expert systems in the Core Module Power Management and Distribution (CM/PMAD) system breadboard with expert systems for the space station at other research centers; and the intelligent data reduction expert system under development.

Weeks, David J.

1987-01-01

374

Power Spectra for Deterministic Chaotic Dynamical Systems  

E-print Network

Power Spectra for Deterministic Chaotic Dynamical Systems Ian Melbourne Georg A. Gottwald 23 July of deterministic chaotic discrete dynamical systems, the power spectrum is analytic except for finitely many for large classes of discrete chaotic dynamical systems, including uniformly hyperbolic (Ax- iom A

Gottwald, Georg A.

375

Power Spectra for Deterministic Chaotic Dynamical Systems  

E-print Network

Power Spectra for Deterministic Chaotic Dynamical Systems Ian Melbourne #3; Georg A. Gottwald y 8 of deterministic chaotic discrete dynamical systems, the power spectrum is analytic except for #12;nitely many for large classes of discrete chaotic dynamical systems, including uniformly hyperbolic (Ax- iom A) di#11

376

78 FR 62616 - Integrated System Power Rates  

Federal Register 2010, 2011, 2012, 2013, 2014

...Federal and non-Federal energy, from the System of Southwestern, at such...Customer's non- Federal power and energy over the System of Southwestern unless such...of non-Federal power and energy over the System of Southwestern or for...

2013-10-22

377

Critical areas: Satellite power systems concepts  

NASA Technical Reports Server (NTRS)

Critical Areas are defined and discussed in the various areas pertinent to satellite power systems. The presentation is grouped into five areas (General, Space Systems, Solar Energy Conversion, Microwave Systems, and Environment/Ecology) with a sixth area (Power Relay) considered separately in an appendix. Areas for Future Consideration as critical areas are discussed in a second appendix.

1975-01-01

378

Power Management in Regenerative Life Support Systems  

NASA Technical Reports Server (NTRS)

Effective management of power can reduce the cost of launch and operation of regenerative life support systems. Variations in power may be quite severe and may manifest as surges or spikes, While the power plant may have some ability to deal with these variations, with batteries for example, over-capacity is expensive and does nothing to address the fundamental issue of excessive demand. Because the power unit must be sized to accommodate the largest demand, avoiding power spikes has the potential to reduce the required size of the power plant while at the same time increasing the dependability of the system. Scheduling of processors can help to reduce potential power spikes. However, not all power-consuming equipment is easily scheduled. Therefore, active power management is needed to further decrease the risk of surges or spikes. We investigate the use of a hierarchical scheme to actively manage power for a model of a regenerative life support system. Local level controllers individually determine subsystem power usage. A higher level controller monitors overall system power and detects surges or spikes. When a surge condition is detected, the higher level controller conducts an 'auction' and describes subsystem power usage to re-allocate power. The result is an overall reduction in total power during a power surge. The auction involves each subsystem making a 'bid' to buy or sell power based on local needs. However, this re-allocation cannot come at the expense of life support function. To this end, participation in the auction is restricted to those processes meeting certain tolerance constraints. These tolerances represent acceptable limits within which system processes can be operated. We present a simulation model and discuss some of our results.

Crawford, Sekou; Pawlowski, Christopher; Finn, Cory; Mead, Susan C. (Technical Monitor)

1999-01-01

379

Flexibility in 21st Century Power Systems  

SciTech Connect

Flexibility of operation--the ability of a power system to respond to change in demand and supply--is a characteristic of all power systems. Flexibility is especially prized in twenty-first century power systems, with higher levels of grid-connected variable renewable energy (primarily, wind and solar). This paper summarizes the analytic frameworks that have emerged to measure this characteristic and distills key principles of flexibility for policy makers.

Cochran, J.; Miller, M.; Zinaman, O.; Milligan, M.; Arent, D.; Palmintier, B.; O'Malley, M.; Mueller, S.; Lannoye, E.; Tuohy, A.; Kujala, B.; Sommer, M.; Holttinen, H.; Kiviluoma, J.; Soonee, S. K.

2014-05-01

380

Combustion powered thermophotovoltaic emitter system  

SciTech Connect

The United States Naval Academy, under interagency agreement with the Department of Energy (DOE), has recently completed an engineering design project for a high temperature thermophotovoltaic (TPV) photon emitter. The design was constrained by the physical geometry and photovoltaic cell type of the DOE TPV generator so that a cylindrical emitter at 1,756 K (2,700 F) was dictated. The final apparatus was to be portable, completely self contained, and was to incorporate cycle efficiency optimization such as exhaust stream recuperation. Through computer modeling and prototype experimentation, a methane fueled emitter system was designed from structural ceramic materials to fulfill the DOE requirements. This paper outlines the engineering design process, discusses obstacles and solutions encountered, and presents the final design. The concept of thermophotovoltaic energy conversion dates to the 1960s and has been the subject of broad research effort. This is a direct energy conversion process that converts thermal energy into electricity with only photonic coupling. The process offers high theoretical efficiency, versatile application as a primary or secondary power cycle, and a number of operational advantages resulting from the lack of a working substance or moving parts.

McHenry, R.S.; Harper, M.J.; Lindler, K.W. [Naval Academy, Annapolis, MD (United States). Naval Architecture, Ocean and Marine Engineering

1995-12-31

381

System aspects of a Space Nuclear Reactor Power System  

Microsoft Academic Search

Selected systems aspects of a 300 kW nuclear reactor power system for spacecraft have been studied. The approach included examination of two candidate missions and their associated spacecraft, and a number of special topics dealing with the power system design and operation. The missions considered were a reusable orbital transfer vehicle and a space-based radar. The special topics included: power

L. Jaffe; T. Fujita; R. Beatty; P. Bhandari; E. Chow; W. Deininger; R. Ewell; M. Grossman; T. Kia; B. Nesmith

1988-01-01

382

Impacts of Power Wheeling on Composite System Adequacy Enhancement  

Microsoft Academic Search

Considerable attention has been devoted to demonstrate reliability enhancement of power systems with power wheeling transactions. The impacts of power wheeling on power systems depends on various factors such as direction, amount of power\\/energy wheeled, system topology and sink or source nodes of power system. The effects on Iran Composite Power System (ICPS) reliability of wheeling energy from Azerbaijan to

M. Fotuhi-Firuzabad; H. Gharagozloo; M. R. Haghifam

2005-01-01

383

Neutral Beam Power System for TPX  

SciTech Connect

The Tokamak Physics Experiment (TPX) will utilize to the maximum extent the existing Tokamak Fusion Test Reactor (TFTR) equipment and facilities. This is particularly true for the TFTR Neutral Beam (NB) system. Most of the NB hardware, plant facilities, auxiliary sub-systems, power systems, service infrastructure, and control systems can be used as is. The major changes in the NB hardware are driven by the new operating duty cycle. The TFTR Neutral Beam was designed for operation of the Sources for 2 seconds every 150 seconds. The TPX requires operation for 1000 seconds every 4500 seconds. During the Conceptual Design Phase of TPX every component of the TFTR NB Electrical Power System was analyzed to verify whether the equipment can meet the new operational requirements with our without modifications. The Power System converts 13.8 kV prime power to controlled pulsed power required at the NB sources. The major equipment involved are circuit breakers, auto and rectifier transformers surge suppression components, power tetrodes, HV Decks, and HVDC power transmission to sources. Thermal models were developed for the power transformers to simulate the new operational requirements. Heat runs were conducted for the power tetrodes to verify capability. Other components were analyzed to verify their thermal limitations. This paper describes the details of the evaluation and redesign of the electrical power system components to meet the TPX operational requirements.

Ramakrishnan, S.; Bowen, O.N.; O`Conner, T.; Edwards, J.; Fromm, N.; Hatcher, R.; Newman, R.; Rossi, G.; Stevenson, T.; von Halle, A.

1993-11-01

384

Thermal management of large pulsed power systems  

NASA Astrophysics Data System (ADS)

Current thermal control technology is reviewed and limitations assessed compared to a typical high pulse power application. Thermal management is a significant weight factor (approximately 50%) of even medium power systems which points to a large potential payback from innovative techniques. Thermal research is recommended in the areas of concentrating and thermovoltaic solar arrays, two phase heat transport loops, direct contact heat exchangers and advanced radiator systems. Air Force space power trends indicate requirements for systems with 10 to 200 KW average power with pulse/average power ratios of 10/1 to 1000/1. Thermal system definition is complicated by the variety of possible power systems although solar and nuclear (Brayton and Thermionic) appear to be the leading candidates.

Haslett, B.

385

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

386

Space Shuttle Upgrades Advanced Hydraulic Power System  

NASA Technical Reports Server (NTRS)

Three Auxiliary Power Units (APU) on the Space Shuttle Orbiter each provide 145 hp shaft power to a hydraulic pump which outputs 3000 psi hydraulic fluid to 41 hydraulic actuators. A hydrazine fuel powered APU utilized throughout the Shuttle program has undergone many improvements, but concerns remain with flight safety, operational cost, critical failure modes, and hydrazine related hazards. The advanced hydraulic power system (AHPS), also known as the electric APU, is being evaluated as an upgrade to replace the hydrazine APU. The AHPS replaces the high-speed turbine and hydrazine fuel supply system with a battery power supply and electric motor/pump that converts 300 volt electrical power to 3000 psi hydraulic power. AHPS upgrade benefits include elimination of toxic hydrazine propellant to improve flight safety, reduction in hazardous ground processing operations, and improved reliability. Development of this upgrade provides many interesting challenges and includes development of four hardware elements that comprise the AHPS system: Battery - The battery provides a high voltage supply of power using lithium ion cells. This is a large battery that must provide 28 kilowatt hours of energy over 99 minutes of operation at 300 volts with a peak power of 130 kilowatts for three seconds. High Voltage Power Distribution and Control (PD&C) - The PD&C distributes electric power from the battery to the EHDU. This 300 volt system includes wiring and components necessary to distribute power and provide fault current protection. Electro-Hydraulic Drive Unit (EHDU) - The EHDU converts electric input power to hydraulic output power. The EHDU must provide over 90 kilowatts of stable, output hydraulic power at 3000 psi with high efficiency and rapid response time. Cooling System - The cooling system provides thermal control of the Orbiter hydraulic fluid and EHDU electronic components. Symposium presentation will provide an overview of the AHPS upgrade, descriptions of the four hardware elements, and a summary of development results to date.

2004-01-01

387

Solar power satellite system definition study  

NASA Technical Reports Server (NTRS)

A synopsis of the study plan for the solar power satellite system is presented. Descriptions of early task progress is reported for the following areas: (1) laser annealing, (2) solid state power amplifiers, (3) rectenna option, (4) construction of an independent electric orbit transfer vehicle, and (5) construction of a 2.5 GW solar power satellite.

1978-01-01

388

Tidal energy in electric power systems  

Microsoft Academic Search

This paper discusses the uses and advantages of tidal energy in restructured power systems. The paper defines the resources as well as the ways in which tidal energy is converted into electricity. The paper also reviews a few tidal power projects around the world. It also shows the working of hydro tidal power plant. A comparative review of renewable energy

S. Sheth; M. Shahidehpour

2005-01-01

389

Acceptance test report: Backup power system  

SciTech Connect

Acceptance Test Report for construction functional testing of Project W-030 Backup Power System. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. Backup power includes a single 125 KW diesel generator, three 10-kva uninterruptible power supply units, and all necessary control.

Cole, D.B. [Westinghouse Hanford Co., Richland, WA (United States)

1996-01-26

390

Mobile Monitoring and Maintenance of Power Systems  

Microsoft Academic Search

Deregulation of power industry in the US and energy crisis in some parts of the world put forward formidable challenges that need to be overcome for successful operation of power networks in the new environment. Monitoring of electric power systems in real-time for reliability, aging status, and presence of incipi- ent faults requires distributed processing of vast amounts of data

Bing JIANG; Alexander V. MAMISHEV

391

Nuclear power for space based systems  

NASA Astrophysics Data System (ADS)

A 100 kWe closed Brayton cycle power conversion system utilizing a recuperator coupled to a NERVA derivative reactor for a lunar power plant is presented. Power plant mass versus recuperator effectiveness, compressor inlet temperature, and turbine pressure ratio are described.

Livingston, J. M.; Ivanenok, Joseph F., III

1991-09-01

392

Bacillus subtilis hlpB encodes a conserved stand-alone HNH nuclease-like protein that is essential for viability unless the hlpB deletion is accompanied by the deletion of genes encoding the AddAB DNA repair complex.  

PubMed

The HNH domain is found in many different proteins in all phylogenetic kingdoms and in many cases confers nuclease activity. We have found that the Bacillus subtilis hlpB (yisB) gene encodes a stand-alone HNH domain, homologs of which are present in several bacterial genomes. We show that the protein we term HlpB is essential for viability. The depletion of HlpB leads to growth arrest and to the generation of cells containing a single, decondensed nucleoid. This apparent condensation-segregation defect was cured by additional hlpB copies in trans. Purified HlpB showed cooperative binding to a variety of double-stranded and single-stranded DNA sequences, depending on the presence of zinc, nickel, or cobalt ions. Binding of HlpB was also influenced by pH and different metals, reminiscent of HNH domains. Lethality of the hlpB deletion was relieved in the absence of addA and of addAB, two genes encoding proteins forming a RecBCD-like end resection complex, but not of recJ, which is responsible for a second end-resectioning avenue. Like AddA-green fluorescent protein (AddA-GFP), functional HlpB-YFP or HlpB-FlAsH fusions were present throughout the cytosol in growing B. subtilis cells. Upon induction of DNA damage, HlpB-FlAsH formed a single focus on the nucleoid in a subset of cells, many of which colocalized with the replication machinery. Our data suggest that HlpB plays a role in DNA repair by rescuing AddAB-mediated recombination intermediates in B. subtilis and possibly also in many other bacteria. PMID:22984257

Pediaditakis, Miriam; Kaufenstein, Miriam; Graumann, Peter L

2012-11-01

393

Water reactive hydrogen fuel cell power system  

SciTech Connect

A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into the fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

2014-11-25

394

Water reactive hydrogen fuel cell power system  

DOEpatents

A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

2014-01-21

395

Modeling of DC spacecraft power systems  

NASA Technical Reports Server (NTRS)

Future spacecraft power systems must be capable of supplying power to various loads. This delivery of power may necessitate the use of high-voltage, high-power dc distribution systems to transmit power from the source to the loads. Using state-of-the-art power conditioning electronics such as dc-dc converters, complex series and parallel configurations may be required at the interface between the source and the distribution system and between the loads and the distribution system. This research will use state-variables to model and simulate a dc spacecraft power system. Each component of the dc power system will be treated as a multiport network, and a state model will be written with the port voltages as the inputs. The state model of a component will be solved independently from the other components using its state transition matrix. A state-space averaging method is developed first in general for any dc-dc switching converter, and then demonstrated in detail for the particular case of the boost power stage. General equations for both steady-state (dc) and dynamic effects (ac) are obtained, from which important transfer functions are derived and applied to a special case of the boost power stage.

Berry, F. C.

1995-01-01

396

Thermal power systems small power systems applications project. Volume 2: Detailed report  

NASA Technical Reports Server (NTRS)

Small power system technology as applied to power plants up to 10 MW in size was considered. Markets for small power systems were characterized and cost goals were established for the project. Candidate power plant system design concepts were selected for evaluation and preliminary performance and cost assessments were made. Breakeven capital costs were determined for leading contenders among the candidate systems. The potential use of small power systems in providing part of the demand for pumping power by the extensive aqueduct system of California, was studied. Criteria and methodologies were developed for the ranking of candidate power plant system design concepts. Experimental power plant concepts of 1 MW rating were studied to define a power plant configuration for subsequent detail design construction, testing and evaluation. Site selection criteria and ground rules were developed.

Marriott, A. T.

1979-01-01

397

Fuel cell powered UPS systems: design considerations  

Microsoft Academic Search

In this paper a 1 kVA fuel cell powered line-interactive UPS system employing modular (fuel cell and power converter) blocks is introduced. Two commercially available PEMFC (25-39 V, 500 W) modules along with suitable DC\\/DC and DC\\/AC power electronic converter modules are employed. A supercapacitor module is also employed to compensate for the instantaneous power fluctuations and overcome the slow

W. Choi; P. Enjeti; J. W. Howze

2003-01-01

398

Systems definition space based power conversion systems: Executive summary  

NASA Technical Reports Server (NTRS)

Potential space-located systems for the generation of electrical power for use on earth were investigated. These systems were of three basic types: (1) systems producing electrical power from solar energy; (2) systems producing electrical power from nuclear reactors; (3) systems for augmenting ground-based solar power plants by orbital sunlight reflectors. Configurations implementing these concepts were developed through an optimization process intended to yield the lowest cost for each. A complete program was developed for each concept, identifying required production rates, quantities of launches, required facilities, etc. Each program was costed in order to provide the electric power cost appropriate to each concept.

1977-01-01

399

Solar dynamic power system definition study  

NASA Technical Reports Server (NTRS)

The solar dynamic power system design and analysis study compared Brayton, alkali-metal Rankine, and free-piston Stirling cycles with silicon planar and GaAs concentrator photovoltaic power systems for application to missions beyond the Phase 2 Space Station level of technology for all power systems. Conceptual designs for Brayton and Stirling power systems were developed for 35 kWe and 7 kWe power levels. All power systems were designed for 7-year end-of-life conditions in low Earth orbit. LiF was selected for thermal energy storage for the solar dynamic systems. Results indicate that the Stirling cycle systems have the highest performance (lowest weight and area) followed by the Brayton cycle, with photovoltaic systems considerably lower in performance. For example, based on the performance assumptions used, the planar silicon power system weight was 55 to 75 percent higher than for the Stirling system. A technology program was developed to address areas wherein significant performance improvements could be realized relative to the current state-of-the-art as represented by Space Station. In addition, a preliminary evaluation of hardenability potential found that solar dynamic systems can be hardened beyond the hardness inherent in the conceptual designs of this study.

Wallin, Wayne E.; Friefeld, Jerry M.

1988-01-01

400

Fault-tolerant electrical power system  

NASA Astrophysics Data System (ADS)

An electrical system that will meet the requirements of a 1990s two-engine fighter is being developed in the Fault-Tolerant Electrical Power System (FTEPS) program, sponsored by the AFWAL Aero Propulsion Laboratory. FTEPS will demonstrate the generation and distribution of fault-tolerant, reliable, electrical power required for future aircraft. The system incorporates MIL-STD-1750A digital processors and MIL-STD-1553B data buses for control and communications. Electrical power is distributed through electrical load management centers by means of solid-state power controllers for fault protection and individual load control. The system will provide uninterruptible power to flight-critical loads such as the flight control and mission computers with sealed lead-acid batteries. Primary power is provided by four 60 kVA variable speed constant frequency generators. Buildup and testing of the FTEPS demonstrator is expected to be complete by May 1988.

Mehdi, Ishaque S.; Weimer, Joseph A.

1987-10-01

401

Modeling for ship power system emulation  

E-print Network

With the U.S. Navy's continued focus on Integrated Fight Thru Power (IFTP) there has been an ever increasing effort to ensure an electrical distribution system that maintains maximum capabilities in the event of system ...

Leghorn, Jeremy T. (Jeremy Thomas)

2009-01-01

402

Study of Systems and Technology for Liquid Hydrogen Production Independent of Fossil Fuels  

NASA Technical Reports Server (NTRS)

Based on Kennedy Space Center siting and logistics requirements and the nonfossil energy resources at the Center, a number of applicable technologies and system candidates for hydrogen production were identified and characterized. A two stage screening of these technologies in the light of specific criteria identified two leading candidates as nonfossil system approaches. Conceptual design and costing of two solar-operated, stand alone systems, one photovoltaic based on and the other involving the power tower approach reveals their technical feasibility as sited as KSC, and the potential for product cost competitiveness with conventional supply approaches in the 1990 to 1210 time period. Conventional water hydrolysis and hydrogen liquefaction subsystems are integrated with the solar subsystems.

Sprafka, R. J.; Escher, W. J. D.; Foster, R. W.; Tison, R. R.; Shingleton, J.; Moore, J. S.; Baker, C. R.

1983-01-01

403

Satellite power systems (SPS) energy conversion and power management  

SciTech Connect

Two reference systems are included in the NASA/DOE reference set - gallium arsenide (GaAs) and silicon (Si). Both the GaAs and Si photovoltaic concepts are coplanar and have a single microwave antenna located at the end of the satellite to provide 5 gigawatts (GW) of power at the utility interface. Impacts are reported that would result to the reference concept from these alternatives to microwave conversion, photovoltaic techniques, solar concentration ratio, and power distribution voltage. 3 refs.

Nussberger, A.A.

1981-01-01

404

High power RF solid state power amplifier system  

NASA Technical Reports Server (NTRS)

A high power, high frequency, solid state power amplifier system includes a plurality of input multiple port splitters for receiving a high-frequency input and for dividing the input into a plurality of outputs and a plurality of solid state amplifier units. Each amplifier unit includes a plurality of amplifiers, and each amplifier is individually connected to one of the outputs of multiport splitters and produces a corresponding amplified output. A plurality of multiport combiners combine the amplified outputs of the amplifiers of each of the amplifier units to a combined output. Automatic level control protection circuitry protects the amplifiers and maintains a substantial constant amplifier power output.

Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

2011-01-01

405

Power System Digital Simulator for Training Dispatcher  

Microsoft Academic Search

To gain knowledge and skill in operative control of power system (PS)i and interconnected power system (IPS) is a by complicalted problem, which demands solving a ,wide circle of scientilk, technical, technological, legal and organizational tasks. I. INTRODUCTION The maintenance of qualification of operational staff on a high level is carried out mainly in the training centres, and in prospect

M. A. Rabinovich; Ju. I. Morzhin; D. M. Parfionov

1995-01-01

406

Intelligent power modules for driving systems [IGBTs  

Microsoft Academic Search

A major challenge for systems engineers is the selection, drive system, optimum operation and implementation of the protection functions of power semiconductor devices. This article describes the Intelligent Power Module (IPM) for driving 3-phase asynchronous machines for the voltage range to 1200 V. Special detailed consideration is given to the continuous protection concept, comprising overvoltage, overload, short circuit, temperature and

K. Reinmuth; H. Stut; L. Lorenz; S. Konrad

1994-01-01

407

Bounding uncertainty in power system dynamic simulations  

Microsoft Academic Search

Parameters of power system models can never be known exactly. Yet dynamic security assessment relies upon the simulations derived from those uncertain models. This paper proposes an approach to quantifying the uncertainty in simulations of power system dynamic behaviour. It is shown that trajectory sensitivities can be used to generate an accurate first order approximation of the trajectory corresponding to

Ian A. Hiskens; M. A. Pai; T. B. Nguyen

2000-01-01

408

Automated System Tests High-Power MOSFET's  

NASA Technical Reports Server (NTRS)

Computer-controlled system tests metal-oxide/semiconductor field-effect transistors (MOSFET's) at high voltages and currents. Measures seven parameters characterizing performance of MOSFET, with view toward obtaining early indication MOSFET defective. Use of test system prior to installation of power MOSFET in high-power circuit saves time and money.

Huston, Steven W.; Wendt, Isabel O.

1994-01-01

409

Expert System Detects Power-Distribution Faults  

NASA Technical Reports Server (NTRS)

Autonomous Power Expert (APEX) computer program is prototype expert-system program detecting faults in electrical-power-distribution system. Assists human operators in diagnosing faults and deciding what adjustments or repairs needed for immediate recovery from faults or for maintenance to correct initially nonthreatening conditions that could develop into faults. Written in Lisp.

Walters, Jerry L.; Quinn, Todd M.

1994-01-01

410

Extended SP-100 reactor power systems capability  

NASA Technical Reports Server (NTRS)

The SP-100 space nuclear power system development program and the NASA Civil Space Technology Initiative (CSTI) are discussed. The advanced technologies being developed for the CSTI high capacity nuclear reactor power system are outlined. The relationship between the CSTI and the Pathfinder project is considered.

Bloomfield, H. S.; Winter, J. M.; Mckissock, B. I.; Sovie, R. J.

1988-01-01

411

High power laser perforating tools and systems  

DOEpatents

ystems devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser perforation of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to perforate such boreholes.

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

2014-04-22

412

Blackouts in electric power transmission systems  

Microsoft Academic Search

In this paper an analysis of blackouts in electric power transmission systems is implemented and studied in simple networks with a regular structure. The proposed model describes load demand and network improvements evolving on a slow timescale as well as the fast dynamics of cascading overloads and outages. The model dynamics are demonstrated on the simple power system networks.

KARAMITSOS IOANNIS; ORFANIDIS KONSTANTINOS

2006-01-01

413

Crowd-Powered Systems Michael Scott Bernstein  

E-print Network

Crowd-Powered Systems by Michael Scott Bernstein S.M., Massachusetts Institute of Technology, 2008. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . David R. Karger Professor Thesis Supervisor Certified by by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leslie A. Kolodziejski Chair, EECS Committee on Graduate Students #12;Crowd-Powered Systems by Michael

Pratt, Vaughan

414

Migrating to the Web: a Web financial information system server  

Microsoft Academic Search

As Intranets are getting more and more popular in business use, the needs for Web information systems are becoming obvious. This paper reports our efforts involved in the implementation of a Web DSS server, which is migrated from a stand-alone DSS server. We describe the various aspects of the system in detail, and propose a generalized Web information system architecture,

Seng-cho T Chou

1998-01-01

415

Tuning of Power System Stabilizers via Genetic Algorithm for Stabilization of Power Systems  

Microsoft Academic Search

\\u000a The paper considers simultaneous placement and tuning of power system stabilizers for stabilization of power systems over\\u000a a wide range of operating conditions using genetic algorithm. The power system operating at various conditions is considered\\u000a as a finite set of plants. The problem of setting parameters of power system stabilizers is converted as a simple optimization\\u000a problem that is solved

Farzan Rashidi; Mehran Rashidi

2004-01-01

416

Anticipatory regulation of complex power systems  

NASA Astrophysics Data System (ADS)

Electric generation control is performed in a distributed manner to supply power to geographically defined control areas. The goal of generation control is to keep the inadvertent flow of power across a control area's boundary as small as possible. If a difference exists between the power supplied and the power demanded in a control area, the load deficit or surplus would be either borrowed from or stored as the kinetic energy in rotating machines on the grid. This thesis addresses the challenge of matching the power demand of a local area grid with the power delivered by a coal-fired power plant. An anticipatory controller for a model power plant is presented to prescribe the power output into the grid. The control system forecasts what the future demand of the power customers in a control area is likely to be and modifies the fuel input to the power generation facility in order to match the predicted demand. A neural network was found to be an adaptable and robust prediction mechanism for the highly nonlinear data found in the power consumption patterns in a residential area of the Commonwealth Edison grid. The corresponding control schedule of the power plant was tuned to match the anticipated demand using an iterative neural network approach. The use of neural networks and an iterative scheme allows the controller design in this research to be applied to a broad range of control problems. The control methodology presented takes into account limits in the magnitude and rate of control actions. Simulations show that this implementation of anticipatory control of electric power demand is effective and especially well suited to dynamic systems that include a dead time or control limitations. The response of the anticipatory neural network control system was shown to be more energy efficient than feedback control for a typical thermal power regulation facility and to have a much smoother, reduced control effort.

Fieno, Thomas Edward

417

Static conversion systems. [for space power reactors  

NASA Technical Reports Server (NTRS)

Historically, all space power systems that have actually flown in space have relied on static energy conversion technology. Thus, static conversion is being considered for space nuclear power systems as well. There are four potential static conversion technologies which should be considered. These include: the alkali metal thermoelectric converter (AMTEC), the thermionic converter, the thermoelectric converter, and the thermophotovoltaic converter (TPV). These four conversion technologies will be described in brief detail along with their current status and development needs. In addition, the systems implications of using each of these conversion technologies with a space nuclear reactor power system will be evaluated and some comparisons made.

Ewell, R.; Mondt, J.

1985-01-01

418

Unified approach to modelling photovoltaic powered systems  

SciTech Connect

The problems associated with modelling of photovoltaic (PV) powered systems stem from the nature of the components involved. The nonlinearity of the PV arrays as well as other components make it difficult to obtain a system of equations that can be solved simultaneously. Graph Theoretic Modelling (GTM) offers a systematic approach to obtaining a system of equations that can be solved efficiently. Nonlinear systems have been studied in the past. The paper extends the GTM approach to model nonlinear systems. A new format for the matrix system of equations is introduced referred to as the Newton-Raphson Mixed Nodal Tableau (NR MNT). The formulation of the NR MNT system of equations can be automated using component stamps. The stamps for several existing components within PV powered systems are introduced. The NR MNT for several PV powered systems are formulated and solved. 15 refs., 8 figs., 2 tabs.

Gupta, S.; Chandrashekar, M. [Univ. of Waterloo, Ontario (Canada)] [Univ. of Waterloo, Ontario (Canada)

1995-12-31

419

Reactive power optimization with different objectives in large power systems including HVDC systems and FACTS devices  

Microsoft Academic Search

Present day power systems are growing in size and complexity of operation with inter connections to neighboring systems, introduction of large generating units, EHV 400\\/765 kV AC transmission systems, HVDC systems and more sophisticated control devices such as FACTS. For planning and operational studies, it requires suitable modeling of all components in the power system, as the number of HVDC

D. Thukaram; S. Lakpathi; K. Ravishankar; S. Surendra

2009-01-01

420

Solar energy thermally powered electrical generating system  

NASA Technical Reports Server (NTRS)

A thermally powered electrical generating system for use in a space vehicle is disclosed. The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat. A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse. The control system is based upon Kalman filter theory.

Owens, William R. (Inventor)

1989-01-01

421

Hydraulically powered dissimilar teleoperated system controller design  

SciTech Connect

This paper will address two issues associated with the implementation of a hydraulically powered dissimilar master-slave teleoperated system. These issues are the overall system control architecture and the design of robust hydraulic servo controllers for the position control problem. Finally, a discussion of overall system performance on an actual teleoperated system will be presented.

Jansen, J.F.; Kress, R.L.

1996-04-01

422

File-system development with stackable layers  

Microsoft Academic Search

Filing services have experienced a number of innovations in recent years, but many of these promising ideas have failed to enter into broad use. One reason is that current filing environments present several barriers to new development. For example, file systems today typically stand alone instead of building on the work of others, and support of new filing services often

John S. Heidemann; Gerald J. Popek

1994-01-01

423

Intelligent systems for strategic power infrastructure defense  

NASA Astrophysics Data System (ADS)

A fault or disturbance in a power system can be severe due to the sources of vulnerability such as human errors, protection and control system failures, a failure of communication networks to deliver critical control signals, and market and load uncertainties. There have been several catastrophic failures resulting from disturbances involving the sources of vulnerability while power systems are designed to withstand disturbances or faults. To avoid catastrophic failures or minimize the impact of a disturbance(s), the state of the power system has to be analyzed correctly and preventive or corrective self-healing control actions have to be deployed. This dissertation addresses two aspects of power systems: Defense system and diagnosis, both concerned with the power system analysis and operation during events involving faults or disturbances. This study is intended to develop a defense system that is able to assess power system vulnerability and to perform self-healing control actions based on the system-wide analysis. In order to meet the requirements of the system-wide analysis, the defense system is designed with multi-agent system technologies. Since power systems are dynamic and uncertain the self-healing control actions need to be adaptive. This study applies the reinforcement learning technique to provide a theoretical basis for adaptation. One of the important issues in adaptation is the convergence of the learning algorithm. An appropriate convergence criterion is derived and an application with a load-shedding scheme is demonstrated in this study. This dissertation also demonstrates the feasibility of the defense system and self-healing control actions through multi-agent system technologies. The other subject of this research is to investigate the methodology for on-line fault diagnosis using the information from Sequence-of-Events Recorders (SER). The proposed multiple-hypothesis analysis generates one or more hypothetical fault scenarios to interpret the SER information. In order to avoid ambiguity of the hypotheses, this study proposes a new method to determine the credibility of each hypothesis. Even if there is not enough SER information, the proposed method is able to perform an accurate fault and malfunction analysis. To avoid exhaustive testing, a minimal set of test scenarios is derived, which is able to handle missing information and SERs. During extreme contingencies or cascading events, fault diagnosis is the first step in the operation of the power system. On-line fault diagnosis provides necessary and correct information for the defense system to make correct and efficient decisions on self-healing control actions. It has been shown in previous studies that incorrect fault diagnosis can lead to catastrophic failures in power systems. Fault diagnosis is an important issue for strategic power infrastructure defense.

Jung, Ju-Hwan

424

Monitoring power system dynamics using phasor measurement technology for power system dynamic security assessment  

Microsoft Academic Search

This paper describes the SCE phasor measurement system, and its usefulness in monitoring the inter-area oscillations occurring in the WECC system and reviews some of the power system operation events recorded by the synchronized phasor measurement system (SPMS).

John W. Ballance; Bharat Bhargava; George D. Rodriguez

2003-01-01

425

Multi-Megawatt Power System Trade Study  

SciTech Connect

As part of a larger task, the Idaho National Engineering and Environmental Laboratory (INEEL) was tasked to perform a trade study comparing liquid-metal cooled reactors having Rankine power conversion systems with gas-cooled reactors having Brayton power conversion systems. This report summarizes the approach, the methodology, and the results of that trade study. Findings suggest that either approach has the possibility to approach the target specific mass of 3-5 kg/kWe for the power system, though it appears either will require improvements to achieve that. Higher reactor temperatures have the most potential for reducing the specific mass of gas-cooled reactors but do not necessarily have a similar effect for liquid-cooled Rankine systems. Fuels development will be the key to higher reactor operating temperatures. Higher temperature turbines will be important for Brayton systems. Both replacing lithium coolant in the primary circuit with gallium and replacing potassium with sodium in the power loop for liquid systems increase system specific mass. Changing the feed pump turbine to an electric motor in Rankine systems has little effect. Key technologies in reducing specific mass are high reactor and radiator operating temperatures, low radiator areal density, and low turbine/generator system masses. Turbine/generator mass tends to dominate overall power system mass for Rankine systems. Radiator mass was dominant for Brayton systems.

Longhurst, Glen Reed; Schnitzler, Bruce Gordon; Parks, Benjamin Travis

2001-11-01

426

INTEGRATED CONTROL OF NEXT GENERATION POWER SYSTEM  

SciTech Connect

Control methodologies provide the necessary data acquisition, analysis and corrective actions needed to maintain the state of an electric power system within acceptable operating limits. These methods are primarily software-based algorithms that are nonfunctional unless properly integrated with system data and the appropriate control devices. Components of the control of power systems today include protective relays, supervisory control and data acquisition (SCADA), distribution automation (DA), feeder automation, software agents, sensors, control devices and communications. Necessary corrective actions are still accomplished using large electromechanical devices such as vacuum, oil and gas-insulated breakers, capacitor banks, regulators, transformer tap changers, reclosers, generators, and more recently FACTS (flexible AC transmission system) devices. The recent evolution of multi-agent system (MAS) technologies has been reviewed and effort made to integrate MAS into next generation power systems. A MAS can be defined as ��a loosely-coupled network of problem solvers that work together to solve problems that are beyond their individual capabilities��. These problem solvers, often called agents, are autonomous and may be heterogeneous in nature. This project has shown that a MAS has significant advantages over a single, monolithic, centralized problem solver for next generation power systems. Various communication media are being used in the electric power system today, including copper, optical fiber and power line carrier (PLC) as well as wireless technologies. These technologies have enabled the deployment of substation automation (SA) at many facilities. Recently, carrier and wireless technologies have been developed and demonstrated on a pilot basis. Hence, efforts have been made by this project to penetrate these communication technologies as an infrastructure for next generation power systems. This project has thus pursued efforts to use specific MAS methods as well as pertinent communications protocols to imbed and assess such technologies in a real electric power distribution system, specifically the Circuit of the Future (CoF) developed by Southern California Edison (SCE). By modeling the behavior and communication for the components of a MAS, the operation and control of the power distribution circuit have been enhanced. The use of MAS to model and integrate a power distribution circuit offers a significantly different approach to the design of next generation power systems. For example, ways to control a power distribution circuit that includes a micro-grid while considering the impacts of thermal constraints, and integrating voltage control and renewable energy sources on the main power system have been pursued. Both computer simulations and laboratory testbeds have been used to demonstrate such technologies in electric power distribution systems. An economic assessment of MAS in electric power systems was also performed during this project. A report on the economic feasibility of MAS for electric power systems was prepared, and particularly discusses the feasibility of incorporating MAS in transmission and distribution (T&D) systems. Also, the commercial viability of deploying MAS in T&D systems has been assessed by developing an initial case study using utility input to estimate the benefits of deploying MAS. In summary, the MAS approach, which had previously been investigated with good success by APERC for naval shipboard applications, has now been applied with promising results for enhancing an electric power distribution circuit, such as the Circuit of the Future developed by Southern California Edison. The results for next generation power systems include better ability to reconfigure circuits, improve protection and enhance reliability.

None

2010-02-28

427

Solar-Augment Potential of U.S. Fossil-Fired Power Plants  

SciTech Connect

Concentrating Solar Power (CSP) systems utilize solar thermal energy for the generation of electric power. This attribute makes it relatively easy to integrate CSP systems with fossil-fired power plants. The 'solar-augment' of fossil power plants offers a lower cost and lower risk alternative to stand-alone solar plant construction. This study ranked the potential to add solar thermal energy to coal-fired and natural gas combined cycle (NGCC) plants found throughout 16 states in the southeast and southwest United States. Each generating unit was ranked in six categories to create an overall score ranging from Excellent to Not Considered. Separate analysis was performed for parabolic trough and power tower technologies due to the difference in the steam temperatures that each can generate. The study found a potential for over 11 GWe of parabolic trough and over 21 GWe of power tower capacity. Power towers offer more capacity and higher quality integration due to the greater steam temperatures that can be achieved. The best sites were in the sunny southwest, but all states had at least one site that ranked Good for augmentation.

Turchi, C.; Langle, N.; Bedilion, R.; Libby, C.

2011-02-01

428

Compact remote sensing system DIM-measurement of traffic-induced air pollution  

Microsoft Academic Search

The paper describes the remote sensing system DIM which works in the pulse mode regime using tunable diode lasers. The system is characterized by its compact design (300 × 150 × 300 mm3) and its stand-alone and mains-independent operation that allows a flexible and mobile use of the system. Two prototypes of the system have been developed. The first version

H.-P. Vollmar; K. Bobey; M. List

1996-01-01

429

Laser power conversion system analysis, volume 2  

NASA Technical Reports Server (NTRS)

The orbit-to-ground laser power conversion system analysis investigated the feasibility and cost effectiveness of converting solar energy into laser energy in space, and transmitting the laser energy to earth for conversion to electrical energy. The analysis included space laser systems with electrical outputs on the ground ranging from 100 to 10,000 MW. The space laser power system was shown to be feasible and a viable alternate to the microwave solar power satellite. The narrow laser beam provides many options and alternatives not attainable with a microwave beam.

Jones, W. S.; Morgan, L. L.; Forsyth, J. B.; Skratt, J. P.

1979-01-01

430

Smart grid management & visualization: Smart Power Management System  

Microsoft Academic Search

This paper presents an innovation Smart Power Management System on Smart Grid. This report consists of 5 major sections: smart power system modeling; real time power system monitoring; system engineering database collection and management; grid condition checking and maintenance; smart grid power system fault analysis. Smart Power Management System enables grid management and visualization to be very effective as it

Grace Q. Tang

2011-01-01

431

Impedance measurements of the Spallation Neutron Source extraction kicker system  

Microsoft Academic Search

Transverse coupling impedance measurements of the Spallation Neutron Source (SNS) beam extraction system were performed and the results are here reported. The SNS beam extraction system is composed from 14 subsystems, each of which consists of a vertical kicker magnet plus a pulse forming network (PFN). Impedance bench measurements were performed on one large and one small aperture magnet, stand-alone

H. Hahn

2004-01-01

432

Integration of decision support systems to improve decision support performance  

Microsoft Academic Search

Decision support system (DSS) is a well-established research and development area. Traditional isolated, stand-alone DSS has been recently facing new challenges. In order to improve the performance of DSS to meet the challenges, research has been actively carried out to develop integrated decision support systems (IDSS). This paper reviews the current research efforts with regard to the development of IDSS.

Shaofeng Liu; Alex H. B. Duffy; Robert Ian Whitfield; Iain M. Boyle

2010-01-01

433

Small reactor power system for space application  

NASA Technical Reports Server (NTRS)

A development history and comparative performance capability evaluation is presented for spacecraft nuclear powerplant Small Reactor Power System alternatives. The choice of power conversion technology depends on the reactor's operating temperature; thermionic, thermoelectric, organic Rankine, and Alkali metal thermoelectric conversion are the primary power conversion subsystem technology alternatives. A tabulation is presented for such spacecraft nuclear reactor test histories as those of SNAP-10A, SP-100, and NERVA.

Shirbacheh, M.

1987-01-01

434

Design of Distortion Parameters Test System for Aircraft Power System  

Microsoft Academic Search

The AC and DC voltage distortion of the aircraft power supply system will cause serious pollution, and seriously affect the aircraft safety performance. According to the requirement of the voltage distortion parameters test of the aircraft power system, the distortion test based on LabVIEW CVI is designed in this paper. The hardware and software of the test system is designed

Shutuan Zhang; Yanli Gao; Chunwan Hu; Wenguang Zhang

2011-01-01

435

Multi-Megawatt Power System Trade Study  

SciTech Connect

A concept study was undertaken to evaluate potential multi-megawatt power sources for nuclear electric propulsion. The nominal electric power requirement was set at 15 MWe with an assumed mission profile of 120 days at full power, 60 days in hot standby, and another 120 days of full power, repeated several times for 7 years of service. Two configurations examined were (1) a gas-cooled reactor based on the NERVA Derivative design, operating a closed cycle Brayton power conversion system; and (2) a molten metal-cooled reactor based on SP-100 technology, driving a boiling potassium Rankine power conversion system. This study considered the relative merits of these two systems, seeking to optimize the specific mass. Conclusions were that either concept appeared capable of approaching the specific mass goal of 3-5 kg/kWe estimated to be needed for this class of mission, though neither could be realized without substantial development in reactor fuels technology, thermal radiator mass efficiency, and power conversion and distribution electronics systems capable of operating at high temperatures. The gas-Brayton systems showed an apparent specific mass advantage (3.53 vs 6.43 kg/kWe for the baseline cases) under the set of assumptions used, but reconciling differences in conservatism in the design algorithms used would make results much more comparable. Brayton systems eliminate the need to deal with two-phase working fluid flows in the microgravity environment of space.

Longhurst, Glen Reed; Schnitzler, Bruce Gordon; Parks, Benjamin Travis

2002-02-01

436

Infrastructure for deployment of power systems  

NASA Technical Reports Server (NTRS)

A preliminary effort in characterizing the types of stationary lunar power systems which may be considered for emplacement on the lunar surface from the proposed initial 100-kW unit in 2003 to later units ranging in power from 25 to 825 kW is presented. Associated with these power systems are their related infrastructure hardware including: (1) electrical cable, wiring, switchgear, and converters; (2) deployable radiator panels; (3) deployable photovoltaic (PV) panels; (4) heat transfer fluid piping and connection joints; (5) power system instrumentation and control equipment; and (6) interface hardware between lunar surface construction/maintenance equipment and power system. This report: (1) presents estimates of the mass and volumes associated with these power systems and their related infrastructure hardware; (2) provides task breakdown description for emplacing this equipment; (3) gives estimated heat, forces, torques, and alignment tolerances for equipment assembly; and (4) provides other important equipment/machinery requirements where applicable. Packaging options for this equipment will be discussed along with necessary site preparation requirements. Design and analysis issues associated with the final emplacement of this power system hardware are also described.

Sprouse, Kenneth M.

1991-01-01

437

An analysis of space power system masses  

NASA Technical Reports Server (NTRS)

Various space electrical power system masses are analyzed with particular emphasis on the power management and distribution (PMAD) portion. The electrical power system (EPS) is divided into functional blocks: source, interconnection, storage, transmission, distribution, system control and load. The PMAD subsystem is defined as all the blocks between the source, storage and load, plus the power conditioning equipment required for the source, storage and load. The EPS mass of a wide range of spacecraft is then classified as source, storage or PMAD and tabulated in a database. The intent of the database is to serve as a reference source for PMAD masses of existing and in-design spacecraft. The PMAD masses in the database range from 40 kg/kW to 183 kg/kW across the spacecraft systems studied. Factors influencing the power system mass are identified. These include the total spacecraft power requirements, total amount of load capacity and physical size of the spacecraft. It is found that a new utility class of power systems, represented by Space Station Freedom, is evolving.

Kenny, Barbara H.; Cull, Ronald C.; Kankam, M. David

1990-01-01

438

Aircraft Photovoltaic Power-Generating System.  

NASA Astrophysics Data System (ADS)

Photovoltaic cells, appropriately cooled and operating in the combustion-created high radiant-intensity environment of gas-turbine and jet engines, may replace the conventional (gearbox-driven) electrical power generators aboard jet aircraft. This study projects significant improvements not only in aircraft electrical power-generating-system performance, but also in overall aircraft performance. Jet -engine design modifications incorporating this concept not only save weight (and thus fuel), but are--in themselves --favorable to jet-engine performance. The dissertation concentrates on operational, constructional, structural, thermal, optical, radiometrical, thin-film, and solid-state theoretical aspects of the overall project. This new electrical power-generating system offers solid-state reliability with electrical power-output capability comparable to that of existing aircraft electromechanical power-generating systems (alternators and generators). In addition to improvements in aircraft performance, significant aircraft fuel- and weight-saving advantages are projected.

Doellner, Oscar Leonard

439

Microwave power transmission beam safety system  

NASA Technical Reports Server (NTRS)

A system in which the characteristics of a microwave power transmission beam are controlled in accordance with power distribution profiles altered due to the detected presence or entrance of an object into the beam which causes changes that are perceived in various received, reflected and scattered power distribution profiles resulting over various receiving elements of the system is presented. The system comprises a microwave power beam radiator array, a microwave power beam receiving antenna array, the radiator array in one embodiment being located on an orbiting spacecraft and the receiving array being located at a ground station. Another embodiment provides a ground based transmitting array and a receiving array aboard an aircraft or airship.

Dickinson, R. M. (inventor)

1980-01-01

440

Engineers stretch power delivery systems with technology  

SciTech Connect

Efforts to increase electric power transmission capacity by four major distributors are described in the article. The Pennsylvania-Jersey-Maryland Power Pool restructuring for operation as an independent system operator is discussed, and equipment upgrades are briefly outlined. The Inex project of American Electric Power, which uses a unified power flow controller to operator a flexible alternating current transmission system (FACTS), is highlighted. Options being considered by Electricite de France are directed at making full use of existing resources; these include optimizing conductor alloy materials and shapes, operating at maximum conductor temperatures, and using FACTS technology to maintain voltages, adjust power flows, and improve network stability. Increasing capacity in the National Grid Company (NGC) system in the United Kingdom involves a combination of load sharing according to thermal capabilities. Technical considerations of NGCs measures to more evenly match load flows to line ratings are also discussed.

Beaty, W.

1996-09-01

441

Photovoltaic power without batteries for continuous cathodic protection  

NASA Technical Reports Server (NTRS)

The COASTSYSTA designed, installed, and started up on 20 Jan. 1990, a state-of-the-art stand alone photovoltaic powered impressed current cathodic protection system (PVCPSYS) not requiring any auxiliary/battery backup power for steel and iron submerged structures. The PVCPSYS installed on 775' of steel sheet piling of a Navy bulkhead is continuing to provide complete, continuous corrosion protection. This has been well documented by COASTSYSTA and verified on-site by the U.S. Army Civil Engineering Research Laboratory, Champaign, Illinois and the Navy Energy Program Office-Photovoltaic Programs, China Lake, California. The Department of Defense (DoD) Photovoltaic Review Committee and Sandia National Laboratories consider this successful and cost effective system a major advance in the application of photovoltaic power. The PVCPSYS uses only renewable energy and is environmentally clean. A patent is pending on the new technology. Other possible PVCPSYS applications are mothballed ships, docks, dams, locks, bridges, marinas, offshore structures, and pipelines. The initial cost savings by installing a PVCPSYS vs. a conventional CP system was in excess of $46,000.00.

Muehl, W. W., Sr.

1994-01-01

442

Low Frequency Oscillations in Longitudinal Power Systems: Experience with Dynamic Stability of Taiwan Power System  

Microsoft Academic Search

Sustained low frequency oscillations have been observed in Taiwan power system which is of longitudinal structure. It is the purpose of this paper to examine the various factors affecting the damping characteristics of these oscillations which caused dynamic instability problem in the operation of Taiwan power system. It is observed that the amount of power flow on the EHV transmission

Yuan-Yih Hsu; Sheng-Wehn Shyue; Chung-Ching Su

1987-01-01

443

Wind for Schools Project Power System Brief  

SciTech Connect

This fact sheet provides an overview of the system components of a Wind Powering America Wind for Schools project. Wind Powering America's (WPA's) Wind for Schools project uses a basic system configuration for each school project. The system incorporates a single SkyStream(TM) wind turbine, a 70-ft guyed tower, disconnect boxes at the base of the turbine and at the school, and an interconnection to the school's electrical system. A detailed description of each system component is provided in this document.

Not Available

2007-08-01

444

Nuclear Power Sources for Space Systems  

NASA Astrophysics Data System (ADS)

This chapter contains the information about nuclear power sources for space systems. Reactor nuclear sources are considered that use the energy of heavy nuclei fission generated by controlled chain fission reaction, as well as the isotope ones producing heat due to the energy of nuclei radioactive decay. Power of reactor nuclear sources is determined by the rate of heavy nuclei fission that may be controlled within a wide range from the zero up to the nominal one. Thermal power of isotope sources cannot be controlled. It is determined by the type and quantity of isotopes and decreases in time due to their radioactive decay. Both, in the reactor sources and in the isotope ones, nuclear power is converted into the thermal one that may be consumed for the coolant heating to produce thrust (Nuclear Power Propulsion System, NPPS) or may be converted into electricity (Nuclear Power Source, NPS) dynamically (a turbine generator) or statically (thermoelectric or thermionic converters). Electric power is supplied to the airborne equipment or is used to produce thrust in electric (ionic, plasma) low-thrust engines. A brief description is presented of the different nuclear systems with reactor and isotopic power sources implemented in Russia and the USA. The information is also given about isotopic sources for the ground-based application, mainly for navigation systems.

Kukharkin, N. E.; Ponomarev-Stepnoi, N. N.; Usov, V. A.

445

Uninterruptible power supply systems provide protection  

Microsoft Academic Search

Nowadays, uninterruptible power supply (UPS) systems are in use throughout the world, helping to supply a wide variety of critical loads, in situations of power outage or anomalies of the mains. This article describes the most common line problems and the relationship between these and the different existing kinds of UPS, showing their operation modes as well as the existent

J. M. Gurrero; Luis Garcia De Vicuna; Javier Uceda

2007-01-01

446

Coexistence of broadband power line communication systems  

Microsoft Academic Search

Recent progress in home networks enhances the application of broadband power line communication (BPL) since it does not require any installation of new communication lines or outlets. However, high-density distribution of BPL devices may bring down the access quality. Besides, the electromagnetic field radiating from the power line may cause interference with other radio systems. Thus, the objective of this

Biao YANG; Ying-hua LÜ; Hong-xin ZHANG

2009-01-01

447

High Power UV LED Industrial Curing Systems  

Microsoft Academic Search

UV curing is a green technology that is largely underutilized because UV radiation sources like Hg Lamps are unreliable and difficult to use. High Power UV LEDs are now efficient enough to replace Hg Lamps, and offer significantly improved performance relative to Hg Lamps. In this study, a modular, scalable high power UV LED curing system was designed and tested,

Karlicek; F. Robert; Robert Sargent

2012-01-01

448

Stochastic Power Control for Cellular Radio Systems  

Microsoft Academic Search

For wireless communication systems, iterative power control algorithms have been proposed to minimize transmit- ter powers while maintaining reliable communication between mobiles and base stations. To derive deterministic convergence results, these algorithms require perfect measurements of one or more of the following parameters: 1) the mobile's signal- to-interference ratio (SIR) at the receiver; 2) the interference experienced by the mobile;

Sennur Ulukus; Roy D. Yates

1997-01-01

449

Transmit power adaptation for multiuser OFDM systems  

Microsoft Academic Search

In this paper, we develop a transmit power adaptation method that maximizes the total data rate of multiuser orthogonal frequency division multiplexing (OFDM) systems in a downlink transmission. We generally formulate the data rate maximization problem by allowing that a subcarrier could be shared by multiple users. The transmit power adaptation scheme is derived by solving the maximization problem via

Jiho Jang; Kwang Bok Lee

2003-01-01

450

Systems analysis on laser beamed power  

NASA Technical Reports Server (NTRS)

The NASA SELENE power beaming program is intended to supply cost-effective power to space assets via Earth-based lasers and active optics systems. Key elements of the program are analyzed, the overall effort is reviewed, and recommendations are presented.

Zeiders, Glenn W., Jr.

1993-01-01

451

Modern transformerless uninterruptable power supply (UPS) systems  

Microsoft Academic Search

Uninterruptable power supplies (UPS) are widely used to supply critical loads and provide reliable and high quality energy to the load. Until recently, on-line UPS systems with isolation transformer have been widely employed. However, transformerless modern UPS systems have been rapidly replacing the old technology due to their superior performance and size attributes. Transformerless UPS systems have utility friendly input

I. Gunes; B. Ustuntepe; A. M. Hava

2009-01-01

452

Control of Distributed Uninterruptible Power Supply Systems  

Microsoft Academic Search

In the last years, the use of distributed uninterruptible power supply (UPS) systems has been growing into the market, becoming an alternative to large conventional UPS systems. In addition, with the increasing interest in renewable energy integration and distributed generation, distributed UPS systems can be a suitable solution for storage energy in micro grids. This paper depicts the most important

Josep M. Guerrero; Lijun Hang; Javier Uceda

2008-01-01

453

Integrated Retail & Wholesale Power System Operation  

E-print Network

", DARPA/ISAT Workshop on Societal Resilience, MIT RLE Conference Center, Cambridge, MA, July 12-13, 2010 of Retail and Wholesale Power System Operations", Agent Technologies for Energy Systems (ATES) Workshop risk management, and system reliability 2) Integration of distributed energy resources (e

Tesfatsion, Leigh

454

Photovoltaic power system design for telecommunications  

NASA Astrophysics Data System (ADS)

The use of photovoltaic power systems for telecommunications, particularly in rural areas, is reviewed. Operating costs and maintenance are discussed. System design, including the collection of insolation data and the calculation of system capacity, is treated. Increasing reliability of photovoltaic modules and storage batteries is noted. The advantages of relay switching over solid state are outlined. Array mountings are described.

Garner, I. F.

455

New Approachesfor Bulk Power System Restoration  

E-print Network

New Approachesfor Bulk Power System Restoration by AbbasKETABI M.Sc in Electrical Engineering to be restored as quickly and reliably as possible, and consequently, detailed restoration plans are necessary system restoration where a great number of simulations, taking into account different system

Paris-Sud XI, Université de

456

Multi-megawatt power system trade study  

NASA Astrophysics Data System (ADS)

A concept study was undertaken to evaluate potential multi-megawatt power sources for nuclear electric propulsion. The nominal electric power requirement was set at 15 MWe with an assumed mission profile of 120 days at full power, 60 days in hot standby, and another 120 days of full power, repeated several times for 7 years of service. Two configurations examined were (1) a gas-cooled reactor based on the NERVA Derivative design, operating a closed cycle Brayton power conversion system; and (2) a molten metal-cooled reactor based on SP-100 technology, driving a boiling potassium Rankine power conversion system. This study considered the relative merits of these two systems, seeking to optimize the specific mass. Conclusions were that either concept appeared capable of reaching the specific mass goal of 3-5 kg/kWe estimated to be needed for this class of mission, though neither could be realized without substantial development in reactor fuels technology, thermal radiator mass and volume efficiency, and power conversion and distribution electronics and systems capable of operating at high temperatures. The gas-Brayton system showed a specific mass advantage (3.17 vs 6.43 kg/kWe for the baseline cases) under the set of assumptions used and eliminated the need to deal with two-phase working fluid flows in the microgravity environment of space. .

Longhurst, Glen R.; Schnitzler, Bruce G.; Parks, Benjamin T.

2002-01-01

457

Space station electrical power system availability study  

NASA Technical Reports Server (NTRS)

ARINC Research Corporation performed a preliminary reliability, and maintainability (RAM) anlaysis of the NASA space station Electric Power Station (EPS). The analysis was performed using the ARINC Research developed UNIRAM RAM assessment methodology and software program. The analysis was performed in two phases: EPS modeling and EPS RAM assessment. The EPS was modeled in four parts: the insolar power generation system, the eclipse power generation system, the power management and distribution system (both ring and radial power distribution control unit (PDCU) architectures), and the power distribution to the inner keel PDCUs. The EPS RAM assessment was conducted in five steps: the use of UNIRAM to perform baseline EPS model analyses and to determine the orbital replacement unit (ORU) criticalities; the determination of EPS sensitivity to on-orbit spared of ORUs and the provision of an indication of which ORUs may need to be spared on-orbit; the determination of EPS sensitivity to changes in ORU reliability; the determination of the expected annual number of ORU failures; and the integration of the power generator system model results with the distribution system model results to assess the full EPS. Conclusions were drawn and recommendations were made.

Turnquist, Scott R.; Twombly, Mark A.

1988-01-01

458

Electric power system supervisory and control system for the 21 century-CC-2000 system  

Microsoft Academic Search

The power system supervisory and control system plays a more and more important role in the security and economic operation of power systems. The power system supervisory and control system includes both energy management systems (EMS) and distribution management systems (DMS), they are employed in transmission system and distributions systems respectively. In this paper the design philosophy of CC-2000 EMS\\/DMD

Wu Yusheng; Wu Xingping; Fan Tao; Fu Shuti; Dong Chunhui; Wang Wen; Sun Chao; Li Lixin

2000-01-01

459

Reconfigurable, Bi-Directional Flexfet Level Shifter for Low-Power, Rad-Hard Integration  

NASA Technical Reports Server (NTRS)

Two prototype Reconfigurable, Bi-directional Flexfet Level Shifters (ReBiLS) have been developed, where one version is a stand-alone component designed to interface between external low voltage and high voltage, and the other version is an embedded integrated circuit (IC) for interface between internal low-voltage logic and external high-voltage components. Targeting stand-alone and embedded circuits separately allows optimization for these distinct applications. Both ReBiLS designs use the commercially available 180-nm Flex fet Independently Double-Gated (IDG) SOI CMOS (silicon on insulator, complementary metal oxide semiconductor) technology. Embedded ReBiLS circuits were integrated with a Reed-Solomon (RS) encoder using CMOS Ultra-Low-Power Radiation Tolerant (CULPRiT) double-gated digital logic circuits. The scope of the project includes: creation of a new high-voltage process, development of ReBiLS circuit designs, and adjustment of the designs to maximize performance through simulation, layout, and manufacture of prototypes. The primary technical objectives were to develop a high-voltage, thick oxide option for the 180-nm Flexfet process, and to develop a stand-alone ReBiLS IC with two 8-channel I/O busses, 1.8 2.5 I/O on the low-voltage pins, 5.0-V-tolerant input and 3.3-V output I/O on the high-voltage pins, and 100-MHz minimum operation with 10-pF external loads. Another objective was to develop an embedded, rad-hard ReBiLS I/O cell with 0.5-V low-voltage operation for interface with core logic, 5.0-V-tolerant input and 3.3-V output I/O pins, and 100-MHz minimum operation with 10- pF external loads. A third objective was to develop a 0.5- V Reed-Solomon Encoder with embedded ReBilS I/O: Transfer the existing CULPRiT RS encoder from a 0.35-micron bulk-CMOS process to the ASI 180-nm Flexfet, rad-hard SOI Process. 0.5-V low-voltage core logic. 5.0-V-tolerant input and 3.3-V output I/O pins. 100-MHz minimum operation with 10- pF external loads. The stand-alone ReBiLS chip will allow system designers to provide efficient bi-directional communication between components operating at different voltages. Embedding the ReBiLS cells into the proven Reed-Solomon encoder will demonstrate the ability to support new product development in a commercially viable, rad-hard, scalable 180-nm SOI CMOS process.

DeGregorio, Kelly; Wilson, Dale G.

2009-01-01

460

Master-Oscillator/Power-Amplifier Laser System  

NASA Technical Reports Server (NTRS)

Master-oscillator/power-amplifier (MOPA) laser system operates in continuous-wave mode or in amplitude-modulation (e.g., pulse) mode by modulation of oscillator current. Power amplifier is laser-diode-pumped neodymium:yttrium lithium fluoride (Nd:YLF) laser; oscillator is laser diode. Offers relatively high efficiency and power. Because drive current to oscillator modulated, external electro-optical modulator not needed. Potential uses include free-space optical communications, coded laser ranging, and generation of high-power, mode-locked pulses.

Yu, Anthony W.; Krainak, Michael A.; Unger, Glenn L.

1994-01-01

461

Harmonic power flow for unbalanced systems  

SciTech Connect

In this paper a harmonic power flow that analyzes harmonics in unbalanced systems is presented. The developed algorithm has two steps which are executed successively: the first is a fundamental frequency power flow for the ac linear network in which non-linear loads are represented by current sources. The second is a frequency-domain iterative Newton-Raphson method to calculate the harmonics generated by non-linear loads. In this second step, the ac linear network is represented by a generalized Thevenin equivalent with respect to the non-linear loads, obtained from the power flow solution. Both linear and non-linear loads are considered in terms of power.

Valcarcel, M.; Mayordomo, J.G. (Univ. Politecnica de Madrid (Spain). Dept. de Ingenieria Electrica)

1993-10-01

462

Satellite power system (SPS) initial insurance evaluation  

SciTech Connect

The beginning of a process to educate the insurance industry about the Satellite Power System is reported. The report is divided into three sections. In the first section a general history describes how space risks are being insured today. This is followed by an attempt to identify the major risks inherent to the SPS. The final section presents a general projection of insurance market reactions to the Satellite Power System.

None

1980-09-01

463

Power Systems Stability Control : Reinforcement Learning Framework  

E-print Network

of the real power system. We present two case studies made on a 4- machine power system model. The first one concerns the design by means of RL algorithms used in off-line mode of a dynamic brake controller-Tilman B28, 4000 Li`ege, BELGIUM. (e-mail : £ ernst,glavic,lwh¤ @montefiore.ulg.ac.be). D. Ernst

Wehenkel, Louis