These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Control algorithms and computer simulation of a stand-alone photovoltaic village power system  

NASA Technical Reports Server (NTRS)

At Stand-Alone Photovoltaic (SAPV) power systems increase in size and load diversity, the design and simulation of control subsystems takes on added importance. These SAPV systems represent 'mini utilities' with commensurate controls requirements, albeit with the added complexity of the energy source (sunlight received) being an uncontrollable variable. This paper briefly describes a stand-alone photovoltaic power/load system computerized simulation model. The model was tested against operational data from the Schuchuli stand-alone village photovoltaic system and has achieved acceptable levels of simulation accuracy. The model can be used to simulate system designs although with probable battery modification.

Groumpos, P. P.; Culler, J. E.; Delombard, R.; Ratajczak, A. F.; Cull, R.

1984-01-01

2

Power Management of a Stand-Alone Wind\\/Photovoltaic\\/Fuel Cell Energy System  

Microsoft Academic Search

This paper proposes an AC-linked hybrid wind\\/photovoltaic (PV)\\/fuel cell (FC) alternative energy system for stand-alone applications. Wind and PV are the primary power sources of the system, and an FC-electrolyzer combination is used as a backup and a long-term storage system. An overall power management strategy is designed for the proposed system to manage power flows among the different energy

Caisheng Wang; M. Hashem Nehrir

2008-01-01

3

Novel Power Control Scheme for Stand-Alone Photovoltaic Generation System  

Microsoft Academic Search

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

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

2006-01-01

4

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

5

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

NASA Technical Reports Server (NTRS)

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.

1981-01-01

6

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

Microsoft Academic Search

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

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

2004-01-01

7

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

8

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

Microsoft Academic Search

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

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

2010-01-01

9

Integrated vs. Stand-Alone Systems.  

ERIC Educational Resources Information Center

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

Kline, Norman

1986-01-01

10

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

Microsoft Academic Search

In Stand-alone Natural Energy Power System (SNEPS), the earlier deterioration of lead-acid battery caused by over recycle times has become the main problems that need to be resolved urgently. Fluctuating power of short period of power supply is one of the main reason of recharge cycle times increasing. Hence, to smooth the fluctuating power, improve power quality and prolong the

Yan Jia; K. Oti; N. Yamamura; M. Ishida

2007-01-01

11

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

12

Integrated energy balance analysis of a stand-alone wind power system for various typical Aegean Sea regions  

NASA Astrophysics Data System (ADS)

The wind power industry is nowadays a mature energy production sector disposing to market commercial wind converters from 50 W up to 5 MW. In the present work the possibility of using stand-alone electricity production systems based on a small wind turbine in order to meet the electricity requirements of remote consumers is analysed for selected Aegean Sea regions possessing representative wind potential types. The proposed configuration results from an extensive long-term meteorological data analysis on a no-load rejection condition basis during the entire time period examined. Accordingly, an integrated energy balance analysis is carried out for the whole time period investigated, including also the system battery depth-of-discharge distribution versus time. Finally, the predicted optimum system configuration is compared to other existing technoeconomic alternatives on a simplified total production cost basis. The results support the viability of similar solutions, especially for areas of high or medium wind potential.

Kaldellis, J. K.; Tsesmelis, M.

2002-01-01

13

Solid State Voltage and Frequency Controller for a Stand Alone Wind Power Generating System  

Microsoft Academic Search

This paper deals with the voltage and frequency controller of a wind turbine driven isolated asynchronous generator. The proposed voltage and frequency controller consists of an insulated gate bipolar junction transistor based voltage source converter along-with battery energy storage system at its dc link. The proposed controller is having bidirectional active and reactive powers flow capability by which it controls

Bhim Singh; Gaurav Kumar Kasal

2008-01-01

14

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

15

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

16

Hybrid renewable energy systems for power generation in stand-alone applications: A review  

Microsoft Academic Search

It has become imperative for the power and energy engineers to look out for the renewable energy sources such as sun, wind, geothermal, ocean and biomass as sustainable, cost-effective and environment friendly alternatives for conventional energy sources. However, the non-availability of these renewable energy resources all the time throughout the year has led to research in the area of hybrid

Prabodh Bajpai; Vaishalee Dash

2012-01-01

17

High-Performance Stand-Alone Photovoltaic Generation System  

Microsoft Academic Search

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

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

2008-01-01

18

Multilevel Inverter Topologies for Stand-Alone PV Systems  

Microsoft Academic Search

This paper shows that versatile stand-alone photovoltaic (PV) systems still demand on at least one battery inverter with improved characteristics of robustness and efficiency, which can be achieved using multilevel topologies. A compilation of the most common topologies of multilevel converters is presented, and it shows which ones are best suitable to implement inverters for stand-alone applications in the range

SÉrgio Daher; JÜrgen Schmid; Fernando L. M. Antunes

2008-01-01

19

Design and simulation of a stand-alone wind-diesel generator with a flywheel energy storage system to supply the required active and reactive power  

Microsoft Academic Search

This paper presents the design and simulation of a stand-alone generation plant, which combines a wind-diesel generator with a flywheel energy storage unit. Without any storage system, the diesel engine has to be continuously operating, resulting in high fuel consumption. The flywheel is designed to supply the rated power during 1.8 minutes. This time is enough to compensate regular wind

I. J. Iglesias; L. Garcia-Tabares; A. Agudo; I. Cruz; L. Arribas

2000-01-01

20

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

NASA Astrophysics Data System (ADS)

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

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

21

Stand-alone photovoltaic generation system with combined storage using lead battery and EDLC  

Microsoft Academic Search

This research is mainly concerned with a stand-alone photovoltaic (PV) generation system for low power DC applications placed where the commercial AC grid connection is not supported. In this paper, basic and improved circuit topologies and the control schemes of stand-alone photovoltaic generation system are proposed. To prevent battery from deep discharge, electric double layer capacitor (EDLC) is incorporated into

Hiroaki Nakayama; Eiji Hiraki; Toshihiko Tanaka; Noriaki Koda; Nobuo Takahashi; Shuji Noda

2008-01-01

22

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

23

Induction generators for stand-alone micro-hydro systems  

SciTech Connect

Micro-hydro schemes have an output of less than 100 kW. They are usually installed to supply electricity to small communities in remote areas which the grid fails to reach. Most micro-hydro schemes are located in the mountainous regions of developing countries, such as the Andes and Himalaya. By using appropriate designs, local skills and local manufacture these schemes can be more cost-effective than large hydro projects. By using self-excited induction generators rather than synchronous generators cost savings and reliability improvements can be achieved, due to the simple construction and inherent robustness of cage induction machines. However, until recently the extra cost and complexity of the voltage and frequency control equipment has more than offset the advantages of using stand-alone induction generators. This paper describes a new approach to controlling induction generators on stand-alone micro-hydro systems. The turbine power-speed characteristic and the relatively high magnetic saturation of modern induction machines are used to reduce the control equipment required. The implementation of the control approach is described along with considerations regarding generator selection and efficiency.

Smith, N.P.A. [Nottingham Trent Univ. (United Kingdom)

1995-12-31

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

A simple model for sizing stand alone photovoltaic systems  

Microsoft Academic Search

We consider a general model for sizing a stand-alone photovoltaic system, using as energy input data the information available in any radiation atlas. The parameters of the model are estimated by multivariate linear regression. The results obtained from a numerical sizing method were used as initial input data to fit the model. The expression proposed allows us to determine the

M. Sidrach-de-Cardona; Ll. Mora López

1998-01-01

26

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

27

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

Microsoft Academic Search

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

Nabil A. Ahmed; Masafumi Miyatake

2006-01-01

28

A stochastic method for stand-alone photovoltaic system sizing  

SciTech Connect

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

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

2010-09-15

29

Design considerations for stand-alone photovoltaic systems  

Microsoft Academic Search

Long-term availability, defined as the total energy delivered over the lifetime of a system divided by the total energy demand, is a major design criterion for stand-alone photovoltaic systems. Using long-term insolation data from 18 US sites and a newly developed performance model, we found that common sizing practices do not reliably provide desired availability. We developed a new technique

R. N. Chapman

1986-01-01

30

A development of the stand-alone Audiotex system  

Microsoft Academic Search

Audiotex is a general system that combines computers and telephones to deliver audio information by adopting text-to-speech (TTS) technology. The TTS is a technology that converts text messages into synthetic speech based on both linguistic analysis of the text and the acoustic knowledge of the production of speech sounds. This paper describes the architecture and features of the Korean stand-alone

Youhyeon Jeong; Sionghun Yi

1996-01-01

31

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

32

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

33

Stand alone ignition devices  

Microsoft Academic Search

Besides restoring traditional independence from outside power sources, stand-alone ignition devices for domestic gas appliances would reduce maintenance and installation costs. A comprehensive literature survey, along with a manufacturer evaluation, identified both new and state-of-the-art concepts for stand-alone systems. The survey's objective criteria included overall feasibility, applicability, reliability, cost\\/benefit ratio, environmental impact, and safety. The evaluation determined the best short-term

Topping

1981-01-01

34

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

35

Stand-alone and Network Capable Pocket Radiation Detection System  

SciTech Connect

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

R. Aryaeinejad

2009-03-01

36

Parametric analysis of stand-alone residential photovoltaic systems and the SOLSTOR simulation model  

Microsoft Academic Search

Grid-connected residential photovoltaic (PV) systems have been studied in great detail during the past few years. However, stand-alone systems have received considerably less attention. This paper describes the results of an evaluation of the economic feasibility of stand-alone systems. The SOLSTOR simulation program, developed by Sandia, was the primary analysis tool. The results indicate that stand-alone PV systems offer considerable

D. L. Caskey; E. A. Aronson; K. D. Murphy

1981-01-01

37

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

38

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

39

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

40

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

41

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

E-print Network

Optimisation of a Small Non Controlled Wind Energy Conversion System for Stand-Alone Applications. This article proposes a method to optimize the design of a small fixed-voltage wind energy conversion system are shown and discussed. Key words Wind energy conversion system, stand-alone application, nonlinear

Paris-Sud XI, Université de

42

Sizing of stand-alone photovoltaic systems using neural network adaptive model  

Microsoft Academic Search

In this paper, we investigate using an adaptive radial basis function (RBF) network with infinite impulse response (IIR) filter in order to find a suitable model for sizing coefficients of the stand-alone photovoltaic (PV) systems, based on minimum of input data. These sizing coefficients allow to the users of stand-alone PV systems to determine the number of solar panel and

Adel Mellit; Mohamed Benghanem

2007-01-01

43

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

44

HIGH FLUX CENTRAL RECEIVERS OF MOLTEN SALTS FOR THE NEW GENERATION OF COMMERCIAL STAND ALONE SOLAR POWER PLANTS  

Microsoft Academic Search

Molten salt technology represents nowadays the most cost-effective technology for electricity generation for stand-alone Solar Power Plants. Although this technology can be applied to both concentrating technologies, Parabolic Through and Central Receiver Systems (CRS), CRS technology can take advantages from its high concentration, allowing to work at high temperatures and therefore with a reduction in the size and cost of

Jesús M. Lat; Manuel Rodríguez; Mónica Álvarez de Lara

45

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

46

Optimal Design of a Stand-Alone Hybrid PV/Fuel Cell Power System for the City of Brest in France  

E-print Network

cell power system without battery storage to supply the electric load demand of the city of Brest resources (i.e. waste incineration power plants), generating savings wherever it is possible, or reporting, battery storage could be needed [8-10]. When the energy storage capacity may be limited, the use

Paris-Sud XI, Université de

47

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

PubMed Central

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

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

1992-01-01

48

A stochastic method for stand-alone photovoltaic system sizing  

Microsoft Academic Search

Photovoltaic systems utilize solar energy to generate electrical energy to meet load demands. Optimal sizing of these systems includes the characterization of solar radiation. Solar radiation at the Earth’s surface has random characteristics and has been the focus of various academic studies. The objective of this study was to stochastically analyze parameters involved in the sizing of photovoltaic generators and

Claudia Valéria Távora Cabral; Delly Oliveira Filho; Antônia Sônia Alves C. Diniz; José Helvecio Martins; Olga Moraes Toledo; Lauro de Vilhena B. Machado Neto

2010-01-01

49

A stochastic method for stand-alone photovoltaic system sizing  

Microsoft Academic Search

Photovoltaic systems utilize solar energy to generate electrical energy to meet load demands. Optimal sizing of these systems includes the characterization of solar radiation. Solar radiation at the Earth's surface has random characteristics and has been the focus of various academic studies. The objective of this study was to stochastically analyze parameters involved in the sizing of photovoltaic generators and

Claudia Valeria Tavora Cabral; Delly Oliveira Filho; Jose Helvecio Martins; Olga Moraes Toledo; Antonia Sonia Alves C. Diniz; Lauro de Vilhena B. Machado Neto

2010-01-01

50

The use of propeller turbines in low head stand alone micro hydro electric power generation units  

Microsoft Academic Search

The mountainous regions of developing countries offer a great potential for small scale hydroelectric schemes, running as stand alone units. Such schemes with power output less than 100kW are usually referred to as micro-hydro power generation units. For low—head sites (available head less than 10 m), there is a vast number of suitable sites in countries with less mountainous areas

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

1995-01-01

51

Parametric analysis of stand-alone residential photovoltaic systems and the SOLSTOR simulation model  

NASA Astrophysics Data System (ADS)

Grid-connected residential photovoltaic (PV) systems have been studied in great detail during the past few years. However, stand-alone systems have received considerably less attention. This paper describes the results of an evaluation of the economic feasibility of stand-alone systems. The SOLSTOR simulation program, developed by Sandia, was the primary analysis tool. The results indicate that stand-alone PV systems offer considerable economic advantage over the fossil-fueled generator systems. This is true even with no escalation of fuel prices, with PV array costs of twice the 1986 DOE goal, with present day battery costs, and in the Northeast as well as in the Southwest part of the United States. The on-site generator was generally used less than 1400 hours per year, and in fact can be eliminated in many cases in the Southwest.

Caskey, D. L.; Aronson, E. A.; Murphy, K. D.

52

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

53

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

54

ESTIMATING WINTERTIME BATTERY TEMPERATURE IN STAND-ALONE PHOTOVOLTAIC SYSTEMS WITH INSULATED BATTERY ENCLOSURES  

Microsoft Academic Search

Storage battery performance is strongly related to temperature: when cold, a battery's capacity, efficiency, and ability to accept charge decline. In cold climates, the lead-acid batteries commonly used in remote stand-alone photovoltaic (PV) systems typically operate at low temperatures during the winter. In order to ensure that the system functions reliably, the battery must be sized to accommodate poor winter

Michael Ross

1998-01-01

55

Evolving Circuits in Seconds: Experiments with a Stand-Alone Board-Level Evolvable System  

Microsoft Academic Search

The purpose of this paper is twofold: first, to illustrate a stand-alone board-level evolvable system (SABLES) and its performance, and second to illustrate some problems that occur during evolution with real hardware in the loop, or when the intention of the user is not completely reflected in the fitness function. SABLES is part of an effort to achieve integrated evolvable

Adrian Stoica; Ricardo Salem Zebulum; Michael I. Ferguson; Didier Keymeulen; Vu Duong

2002-01-01

56

Design and Implementation of a NetLogo Interface for the Stand-Alone FYPA System  

E-print Network

Design and Implementation of a NetLogo Interface for the Stand-Alone FYPA System Daniela Briola with a graphical interface implemented in NetLogo for off-line visualization, that we describe here in details. I implemented by means of a NetLogo [6] program able to read the output files of the agents and to graphically

Mascardi, Viviana

57

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

PubMed

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

2005-03-01

58

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

Microsoft Academic Search

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

L. Barote; C. Marinescu

2009-01-01

59

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

60

Design of stand-alone brackish water desalination wind energy system for Jordan  

SciTech Connect

More than 100 underground water wells drilled in Jordan are known to have brackish water with total desolved solids (TDS) over 1500 ppm but not greater than 4000 ppm. The world standard for potable water limits the TDS count to 500 ppm in addition to being free from live microorganisms or dangerous mineral and organic substances. A reverse osmosis desalination scheme powered by a stand-alone wind energy converter (WEC) is proposed to produce fresh water water from wells located in potentially high-wind sites. The purpose of this study if to present the main design parameters and economic estimates of a wind-assisted RO system using a diesel engine as the baseline energy source and an electric wind turbine for the wind energy source. It is found that brackish water pumping and desalinating using WECs costs 0.67 to 1.16 JD/m[sup 3] (JD = Jordanian Dinar, 1US$ = 0.68 JD), which is less than using conventional diesel engines especially in remote areas. In addition, the wind-reverse osmosis system becomes more economically feasible for higher annual production rates or in good wind regimes.

Habali, S.M.; Saleh, I.A.

1994-06-01

61

Study of locally manufactured motor vehicle batteries in stand alone home photovoltaic systems  

SciTech Connect

Analysis of voltage, current, specific gravity, and temperature was performed on locally manufactured lead acid batteries operating in stand alone home photovoltaic (SAHPV) systems in the Dominican Republic. While voltage, charge/discharge current, and specific gravity of most batteries were within reasonable limits, there were indications of batteries spending an excessive time discharged and some incidents of overcharge. During charging above 1 amp, ambient temperatures were 6 to 13 C above the optimal operating temperature (25 C) and battery temperatures were 9 to 20 C above 25 C. Examination of worn out batteries from these SAHPV systems revealed that the majority had deteriorated positive plates and/or sulfation, while a smaller number showed signs of spalling. High temperature was determined to be a significant factor contributing to the premature failure of locally manufactured lead acid batteries operating in these systems.

Fernandez, S.

1999-07-01

62

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

63

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

64

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

Microsoft Academic Search

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

Hua Geng; Bin Wu; Wei Huang

2011-01-01

65

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

66

Singleloop voltage and frequency control of stand-alone three-phase four-wire renewable energy conversion system with battery storage  

Microsoft Academic Search

In this paper, single control loop based scheme for regulation of voltage and frequency of Self Excited Induction Generator (SEIG) based stand-alone 3-phase 4-wire renewable energy conversion system under source and balanced\\/unbalanced load perturbations is presented. The regulation is accomplished by maintaining reactive and active power balance across individual phases of SEIG using a Generalized Impedance Controller (GIC). GIC is

J. K. Chatterjee; Priyesh J. Chauhan

2011-01-01

67

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

Microsoft Academic Search

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

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

2006-01-01

68

The synthesis of solar radiation data for sizing stand-alone photovoltaic systems  

Microsoft Academic Search

The author describes a model that synthesizes long-term hourly insolation data from monthly average insolation data using statistical models developed from 23.5 years of hourly data from 20 weather stations scattering across the United States. This model was developed specifically for sizing stand-along photovoltaic power systems and was therefore verified by comparing system performances resulting from the synthetic data with

Richard N. Chapman

1990-01-01

69

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

E-print Network

The objective of this work is to investigate the Radial Basis Function Neural Networks (RBFN) to identifying and modeling the optimal sizing couples of stand-alone photovoltaic (PV) system using a minimum of input data, These optimal couples allow...

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

2004-01-01

70

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

SciTech Connect

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

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

2010-05-15

71

Control of Stand-Alone Photovoltaic System Using Fuzzy-Logic Controller  

E-print Network

and acceptable satisfactions rates they do not perform an optimisation of the PV plant for the local climate conditions. The power supplied by solar arrays depends on the radiation, temperature and array voltage, the operation point of a load connected...

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

2004-01-01

72

Design of a predictive control strategy for integration of stand-alone wind\\/diesel system  

Microsoft Academic Search

Power control of variable speed wind turbines coupled with squirrel cage induction generators is difficult and suffers from some fundamental problems. If this type of wind turbines are applied to remote areas, they cannot stabilize frequency and voltage of the grid in acceptable limits. Changes in the load during one day also make this problem harder to deal with. In

Behzad Sedaghat; Abolfazl Jalilvand; Reza Noroozian

2010-01-01

73

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

Microsoft Academic Search

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

Saeed Jalilzadeh; Ahmad Rohani; Hossein Kord; Mojtaba Nemati

2009-01-01

74

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

E-print Network

, USA ABSTRACT In this work, a low-cost, low-volume, low-maintenance, small-scale compressed-air energy of a unique energy-efficient, small- scale, compressed-air energy storage system that can be specifically and discharge and heat- exchange capabilities. The workings of a CAES system comprise of a compression phase

Deymier, Pierre

75

Design and analysis of stand-alone hydrogen energy systems with different renewable sources  

Microsoft Academic Search

One of the most interesting developments of energy systems based on the utilization of hydrogen is their integration with renewable sources of energy (RES). In fact, hydrogen can operate as a storage and carrying medium of these primary sources. The design and operation of the system could change noticeably, depending on the type and availability of the primary source. In

Massimo Santarelli; Sara Macagno

2004-01-01

76

An Investigation of Architectures For Integration Of Stand-Alone INS And GPS Navigation Systems.  

E-print Network

??Inertial navigation systems (INSs) have the well-known advantages of being self-contained, weatherproof, jam-proof, and non-self-revealing while providing stable navigation information with little high-frequency noise. However,… (more)

Dikshit, Veena G

2006-01-01

77

Robust optimal sizing of an hybrid energy stand-alone system  

E-print Network

Mar 24, 2014 ... In Section 2 we describe the system operation and the notations. In Section ... variables are integer and the recourse variables are real. ... polynomial time by using dynamic programming, contrary to the general case.

2014-03-24

78

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

NASA Astrophysics Data System (ADS)

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. The approach is encoded in a model called Populations-Order-Physiology (POP). We demonstrate the behavior and performance of POP coupled to the Community Atmosphere Biosphere Land Exchange model (CABLE) applied along the Northern Australian Tropical Transect, featuring gradients in rainfall and fire disturbance. The model is able to simultaneously reproduce observation-based estimates of key functional and structural variables along the transect, namely gross primary production, tree foliage projective cover, basal area, and maximum tree height. Prospects for the use of POP to address current vegetation dynamic deficiencies in earth system modeling are discussed.

Haverd, Vanessa; Smith, Benjamin; Cook, Garry D.; Briggs, Peter R.; Nieradzik, Lars; Roxburgh, Stephen H.; Liedloff, Adam; Meyer, Carl P.; Canadell, Josep G.

2013-10-01

79

Voltage frequency controller for stand alone WECS employing permanent magnet synchronous generator  

Microsoft Academic Search

In this paper, a battery energy storage system (BESS) based voltage and frequency (VF) controller based on isolated three-leg VSC with a zig-zag transformer is proposed for stand alone power generation using a permanent magnet synchronous generator (PMSG). An isolated distributed generation (DG) system is realised using fixed pitch wind turbine. The proposed stand alone wind energy conversion system (WECS)

Bhim Singh; V. Sheeja; R. Uma; P. Jayaprakash

2009-01-01

80

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

Microsoft Academic Search

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

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

2007-01-01

81

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

Microsoft Academic Search

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

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

2010-01-01

82

Why icons cannot stand alone  

Microsoft Academic Search

What is the point of this paper? That an icon is like a logogram, the type of object that was created at the start of the development of writing; therefore, when first seen, an icon cannot be expected to stand alone, without descriptive, supporting material supplied as written text.

Katherine Haramundanis

1996-01-01

83

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

E-print Network

Current(A) Real Power3Ã? (W) Reactive Power3Ã? (VAR) RMS CurrentIA (A) RMS CurrentIC (A) Figure A-3: Ramp TestsAppendix 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

84

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

85

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

ERIC Educational Resources Information Center

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

Hegarty, Kevin

1988-01-01

86

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

87

A stand-alone tree demography and landscape structure module for Earth system models: integration with global forest data  

NASA Astrophysics Data System (ADS)

Poorly constrained rates of biomass turnover are a key limitation of Earth system models (ESM). In light of this, we recently proposed a new approach encoded in a model called Populations-Order-Physiology (POP), for the simulation of woody ecosystem stand dynamics, demography and disturbance-mediated heterogeneity. POP is suitable for continental to global applications and designed for coupling to the terrestrial ecosystem component of any ESM. POP bridges the gap between first generation Dynamic Vegetation Models (DVMs) with simple large-area parameterisations of woody biomass (typically used in current ESMs) and complex second generation DVMs, that explicitly simulate demographic processes and landscape heterogeneity of forests. The key simplification in the POP approach, compared with second-generation DVMs, is to compute physiological processes such as assimilation at grid-scale (with CABLE or a similar land surface model), but to partition the grid-scale biomass increment among age classes defined at sub grid-scale, each subject to its own dynamics. POP was successfully demonstrated along a savanna transect in northern Australia, replicating the effects of strong rainfall and fire disturbance gradients on observed stand productivity and structure. Here, we extend the application of POP to a range of forest types around the globe, employing paired observations of stem biomass and density from forest inventory data to calibrate model parameters governing stand demography and biomass evolution. The calibrated POP model is then coupled to the CABLE land surface model and the combined model (CABLE-POP) is evaluated against leaf-stem allometry observations from forest stands ranging in age from 3 to 200 yr. Results indicate that simulated biomass pools conform well with observed allometry. We conclude that POP represents a preferable alternative to large-area parameterisations of woody biomass turnover, typically used in current ESMs.

Haverd, V.; Smith, B.; Nieradzik, L. P.; Briggs, P. R.

2014-02-01

88

Creating a stand-alone fundraising foundation.  

PubMed

When considering a stand-alone fundraising foundation, healthcare organizations should: Review the costs and benefits of starting a separate stand-alone foundation. Perform a competitive analysis to see which hospitals use them. Work with a team of legal, development, and investment advisory experts who can help map out a plan. Review governance requirements. Develop an investment policy statement. PMID:23088062

Dillingham, Walter J; Weiss, Leigh H; Lawson, John M

2012-10-01

89

Solar photovoltaics: Stand alone applications  

Microsoft Academic Search

The Lewis Research Center involvement in space photovoltaic research and development and in using photovoltaics for terrestrial applications is described with emphasis on applications in which the normal source of power may be a diesel generator, batteries, or other types of power not connected to a utility grid. Once an application is processed, technology is developed and demonstrated with a

J. N. Deyo

1980-01-01

90

Remote hybrid power systems  

Microsoft Academic Search

This paper provides an overview of the emerging technology of remote, stand-alone electrical power systems featuring a renewable source (wind or photovoltaics [PV]) as well as a diesel generator, with or without an energy storage device. Other stand-alone power systems are discussed briefly, mainly to emphasize the domain of hybrid systems. The history of hybrid systems is reviewed, beginning with

C. D. Barley; C. B. Winn

1997-01-01

91

Why science cannot stand alone.  

PubMed

In an era in which certain arenas of scientific research have become increasingly controversial, this article critically evaluates what it means to "believe in science." Many scientists today seem to claim a sovereign right to no political interference under the rubric of freedom. This article questions such a notion, and explores the dominance of science and the silencing of moral voices by undertaking two brief investigations-the first into National Socialist Germany, which insisted that it was defined by "applied biology," and the second into the world of contemporary American biomedicine. When all ethical barriers are eradicated, it seems that a will to power takes over-manifested in Nazi Germany's vaunted scientific autonomy. In light of these sobering historical examples, this article reminds the reader that members of the public, including physicians, rightly deliberate about how to conscientiously order their lives together, and that part of that instrinsically political deliberation is to set limits to the ways medical science is applied and what scientists may do in pursuit of their goals. PMID:18850304

Elshtain, Jean Bethke

2008-01-01

92

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

E-print Network

energy, wind and solar are the most accessible ones and they are good complement to each other. However on transmission line and other equipment. Therefore photovoltaic panels and wind turbines have great prospect. The most popular integration of renewable energy is through wind turbine and solar panels. Figure 2 shows

Lavaei, Javad

93

Renewable hybrid stand-alone telecom power system modeling and analysis  

Microsoft Academic Search

At the telecom service providers' installations, the problem of poor grid electricity supply is tackled by using diesel generators. These generators, however, entail a major problem in transportation and storage of diesel with noise pollution. Decentralized distributed generation technologies based on renewable energy resources such as solar photo voltaic (SPV) or\\/and wind turbine generators (WTG) address the above barriers to

Prabodh Bajpai; N. P. Prakshan; N. K. Kishore

2009-01-01

94

Application of valve-regulated lead-acid batteries for storage of solar electricity in stand-alone photovoltaic systems in the northwest areas of China  

Microsoft Academic Search

Photovoltaic (PV) installations for solar electric power generation are being established rapidly in the northwest areas of China, and it is increasingly important for these power systems to have reliable and cost effective energy storage. The lead-acid battery is the more commonly used storage technology for PV systems due to its low cost and its wide availability. However, analysis shows

Shounan Hua; Qingshen Zhou; Delong Kong; Jianping Ma

2006-01-01

95

Stand Alone Spacecraft Attitude Determination Using GPS Signals  

Microsoft Academic Search

This paper presents results of stand-alone GPS (Global Positioning System) attitude determination using real flight data from UoSat-12 mini-satellite. Integer ambiguities in the GPS measurements are resolved using a new developed algorithm, without attitude knowledge requirement. An estimator based on a standard EKF (Extended Kalman Filter) uses all GPS measurements to enable continued attitude determination taking into account the spacecraft

S. Purivigraipong

96

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

PubMed Central

Decompression surgery for lumbar spinal stenosis is a common procedure. After surgery, segmental instability sometimes occurs, therefore, different methods for restabilization have been developed. Dynamic stabilization systems have been designed to improve segmental stability. In this study, clinical results of patients with lumbar spinal stenosis that underwent decompression and stabilization with the Accuflex dynamic system are presented; clinical, radiographic, and magnetic resonance imaging (MRI) findings are fully described. Improvements in all clinical measurements, including visual analog scale for back and leg pain, Oswestry disability index, and SF-36 health status survey were noticed. At a 2-year follow-up, 22.22% of patients required hardware removal due to fatigue while in 83% of them no progression of disk degeneration was observed after implantation of the Accuflex system. Additionally, as demonstrated by the MRI images at follow up, three patients (16%) showed disk rehydration with one grade higher on the Pfirmann classification. Although a relatively high hardware failure was observed (22.22%), the use of the dynamic stabilization system Accuflex posterior to decompression procedures, showed clinical benefits and stopped the degenerative process in 83% the patients. PMID:20496039

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

2010-01-01

97

A stand-alone tree demography and landscape structure module for Earth system models: integration with inventory data from temperate and boreal forests  

NASA Astrophysics Data System (ADS)

Poorly constrained rates of biomass turnover are a key limitation of Earth system models (ESMs). In light of this, we recently proposed a new approach encoded in a model called Populations-Order-Physiology (POP), for the simulation of woody ecosystem stand dynamics, demography and disturbance-mediated heterogeneity. POP is suitable for continental to global applications and designed for coupling to the terrestrial ecosystem component of any ESM. POP bridges the gap between first-generation dynamic vegetation models (DVMs) with simple large-area parameterisations of woody biomass (typically used in current ESMs) and complex second-generation DVMs that explicitly simulate demographic processes and landscape heterogeneity of forests. The key simplification in the POP approach, compared with second-generation DVMs, is to compute physiological processes such as assimilation at grid-scale (with CABLE (Community Atmosphere Biosphere Land Exchange) or a similar land surface model), but to partition the grid-scale biomass increment among age classes defined at sub-grid-scale, each subject to its own dynamics. POP was successfully demonstrated along a savanna transect in northern Australia, replicating the effects of strong rainfall and fire disturbance gradients on observed stand productivity and structure. Here, we extend the application of POP to wide-ranging temporal and boreal forests, employing paired observations of stem biomass and density from forest inventory data to calibrate model parameters governing stand demography and biomass evolution. The calibrated POP model is then coupled to the CABLE land surface model, and the combined model (CABLE-POP) is evaluated against leaf-stem allometry observations from forest stands ranging in age from 3 to 200 year. Results indicate that simulated biomass pools conform well with observed allometry. We conclude that POP represents an ecologically plausible and efficient alternative to large-area parameterisations of woody biomass turnover, typically used in current ESMs.

Haverd, V.; Smith, B.; Nieradzik, L. P.; Briggs, P. R.

2014-08-01

98

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

99

A stand-alone ECG abnormality detector  

Microsoft Academic Search

Monitoring the ECG (Electrocardiogram) of patients with cardiac disorder is of paramount importance since they may undergo cardiac arrhythmias even without noticing it. Majority of existing devices for this purpose are only capable of recording ECG of patients which are analyzed later on by cardiologists. This paper presents a new system developed to continuously monitor the ECG of patients and

H. M. K. G. S. Jayasumana; T. M. U. A. S. Thennakoon; C. M. R. B. Chandrasekara; M. T. Sandaruwan; A. A. Pasqual; N. D. Nanayakkara

2010-01-01

100

Ris-R-1480(EN) Stand-alone version of the 11kW Gaia  

E-print Network

W Gaia wind turbine Department: Wind Energy Department Risø-R-1480(EN) September 2004 Abstract (max. 2000 can be a very good alternative energy source for such communities. Wind power can then replace someRisø-R-1480(EN) Stand-alone version of the 11kW Gaia wind turbine Henrik Bindner Pedro A.C. Rosas

101

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

Microsoft Academic Search

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

Remus Teodorescu; Frede Blaabjerg

2004-01-01

102

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

...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

103

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

Microsoft Academic Search

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

B. Venkatesa Perumal; Jayanta K. Chatterjee

2008-01-01

104

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

105

University of Essex Rules of Assessment for stand-alone Graduate Certificates UNIVERSITY OF ESSEX  

E-print Network

University of Essex Rules of Assessment for stand-alone Graduate Certificates UNIVERSITY OF ESSEX - #12;University of Essex Rules of Assessment for stand-alone Graduate Certificates If a student fails

106

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 of Essex Rules of Assessment for stand-alone Postgraduate Diplomas A Pass with Merit or Distinction Results of Essex Rules of Assessment for stand-alone Postgraduate Diplomas Departments will iden

107

Magnetic field measurements near stand-alone transformer stations.  

PubMed

Extremely low-frequency (ELF) magnetic field (MF) measurements around and above three stand-alone 22/0.4-kV transformer stations have been performed. The low-voltage (LV) cables between the transformer and the LV switchgear were found to be the major source of strong ELF MFs of limited spatial extent. The strong fields measured above the transformer stations support the assessment method, to be used in future epidemiological studies, of classifying apartments located right above the transformer stations as highly exposed to MFs. The results of the MF measurements above the ground around the transformer stations provide a basis for the assessment of the option of implementing precautionary procedures. PMID:23836796

Kandel, Shaiela; Hareuveny, Ronen; Yitzhak, Nir-Mordechay; Ruppin, Raphael

2013-12-01

108

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 for the course is 50. #12;University of Essex Rules of Assessment for stand-alone Postgraduate Diplomas Page 2

Codling, Edward A.

109

University of Essex Rules of Assessment for stand-alone Graduate Certificates Page 1 of 3  

E-print Network

University of Essex Rules of Assessment for stand-alone Graduate Certificates Page 1 of 3 UNIVERSITY OF ESSEX GRADUATE SCHOOL RULES OF ASSESSMENT FOR GRADUATE CERTIFICATES 2011/12 (where offered;University of Essex Rules of Assessment for stand-alone Graduate Certificates Page 2 of 3 4.1 If a student

Codling, Edward A.

110

Six-phase induction machine operating as a stand-alone self-excited induction generator  

E-print Network

Six-phase induction machine operating as a stand- alone self-excited induction generator Kamel. Keywords--Six-phase induction machine, self-excited induction generators, magnetic saturation, renewable-phase induction machine operating as a stand-alone self-excited induction generator and supplying various loads

Brest, Université de

111

Probabilistic modeling of solar power systems  

Microsoft Academic Search

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

Fayssal M. Safie

1989-01-01

112

Casinos in context : the impacts of stand-alone casino development on urban neighborhoods  

E-print Network

As the stigma of gambling fades and governments seek more sources of revenue the urban casino is becoming more common. Many of these are legalized to operate with limited competition in their state, standing alone in their ...

Schray, Luke J. (Luke Joseph)

2007-01-01

113

Stand Alone Pressure Measurement Device (SAPMD) for the space shuttle Orbiter, part 2  

NASA Technical Reports Server (NTRS)

The Stand Alone Pressure Measurement Device (SAPMD) specifications are examined. The HP.SAPMD GSE software is listed; the HP/SGA readme program is presented; and the SPMD acceptance test procedure is described.

Tomlinson, Bill

1989-01-01

114

Market assessment of photovoltaic power systems for agricultural applications in Nigeria  

NASA Astrophysics Data System (ADS)

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.

1981-10-01

115

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

116

She stands alone: Pakistani woman film director, Shireen Pasha.  

PubMed

This article describes the activities of film director Shireen Pasha in promoting truth in the mass media in Pakistan. Pasha is described as one who finds it inexcusable in a state-subsidized system that national problems of poverty are not aired openly. Pasha has pursued the goal of exposing the real lives of Pakistanis on film in contrast to the publicly aired segments of "pretty girls in nice drawing rooms." Foreign channels available through satellite communications technology are viewed by Pasha as inappropriate with regard to people's needs and uncreative. Pakistan began with one channel, PTV, which recently refused to air her documentary on living conditions in Pakistan's rural areas "The Travelogue Pakistan." "The Walled City of Lahore" was her film about life in the old city. Both films poetically depicted the honor of humans and their struggle to stay alive. Some of her documentaries are made to show the value of indigenous skills, centuries old know-how, and traditions, regardless of the poverty. Pasha is described as fighting with PTV management over use of resources. Pasha desires to invest in training people to do documentaries or be more field-oriented rather than investing in equipment. Pasha joined PTV in 1975 and left in 1990. Pasha is recognized for her isolation as a woman in the business world, her commitment to exposing remote cultures and truth, and the odds she must confront in attaining her goals. Pasha is committed to doing extensive research, usually conducted during the summer months, in order to construct a credible story line that is produced usually during the winter months. One model of film story line is defined as one where women are portrayed as starting from an indigenous skill or knowledge and shifting to a greater position of power and control over their lives. Pasha believes that people who make films have the responsibility to evoke a reaction in people and to offer solutions. Two acclaimed films, which were supported by USAID and the government, were "Before It's Too Late" and "Only One Way." Both deal with resource issues and the environment. She is currently director of her own film house, The Film Makers, in Lahore. After graduating from the National College of Arts in 1968, she furthered her education in the US in the history of art. PMID:12290699

Mustafa, A

1995-01-01

117

Array structure design handbook for stand alone photovoltaic applications  

NASA Technical Reports Server (NTRS)

This handbook will permit the user to design a low-cost structure for a variety of photovoltaic system applications under 10 kW. Any presently commercially available photovoltaic modules may be used. Design alternatives are provided for different generic structure types, structural materials, and electric interfaces. The use of a hand-held calculator is sufficient to perform the necessary calculations for the array designs.

Didelot, R. C.

1980-01-01

118

Performance Analysis of a Stand-Alone Permanent-Magnet Induction Generator with Single-Phase Output  

NASA Astrophysics Data System (ADS)

The performance of a stand-alone permanent-magnet induction generator (PMIG) with single-phase output is analyzed using the method of symmetrical components and is compared to that of the same-sized conventional induction generator (IG). Experimental results conducted on a 2.2-kW testing machine are also provided to justify the theoretical analysis. Calculation and experimental results show that containing a permanent-magnet (PM) rotor generates electric power without fail and contributes to the improvement of efficiency and frequency variation.

Tsuda, Toshihiro; Fukami, Tadashi; Kanamaru, Yasunori; Miyamoto, Toshio

119

Experimental study for wind power - hydrogen energy system with energy capacitor system  

Microsoft Academic Search

The most serious defects of a wind turbine system are instability of the output and power transmission problem. This report aims at a stand-alone wind turbine system with a hydrogen generator (wind power - hydrogen energy system). In comparison with electric, hydrogen is suitable for energy storage and transport. So this system improves fluctuating output power of the wind turbine

M. Nitta; S. Hashimoto; N. Sekiguchi; Y. Kouchi; T. Yachi; T. Tani

2003-01-01

120

Setup of the Mössbauer spectrometer based on stand-alone instruments - A case study  

NASA Astrophysics Data System (ADS)

In this study, an optional assembling of a Mössbauer spectrometer based on stand-alone instruments (an Agilent 33521A function generator and an Agilent DSO-X 2002A digital oscilloscope) is presented. The main goal is to identify the possible functional limits of selected instruments used as standard and cheap laboratory equipment in comparison to the special and expensive devices. For communication with the instruments and to perform all measurement tasks, an application was created in the LabVIEW{trade mark, serif} 2013 (National Instruments), a graphical programming environment. In addition to the instruments, the standard ORTEC NIM system was used in the gamma-ray detection part of the system. Development of the control application to accumulate Mössbauer spectra with synchronization of the reference signal generation and detectors signal processing is presented. Despite the fact that the setup of the spectrometer was correct and usable for daily research, some disadvantages were found. The sources of high measurement dead time value were identified mainly in the oscilloscope usage. Possible solutions to additionally increase the performance of the proposed system are discussed in details.

Kou?il, Lukáš; Kohout, Pavel; Novák, Petr; Nava?ík, Jakub; Pechoušek, Ji?í

2014-10-01

121

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' and `Arithmetic Average'. Students will receive the more favourable result of the two. #12;University of Essex

Codling, Edward A.

122

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

E-print Network

University of Essex Rules of Assessment for stand-alone Postgraduate Certificates Page 1 of 4 UNIVERSITY OF ESSEX GRADUATE SCHOOL RULES OF ASSESSMENT FOR POSTGRADUATE CERTIFICATES 2011/12 (where offered' and `Arithmetic Average'. Students will receive the more favourable result of the two. #12;University of Essex

Codling, Edward A.

123

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

E-print Network

University of Essex Rules of Assessment for stand-alone Postgraduate Certificates UNIVERSITY OF ESSEX GRADUATE SCHOOL RULES OF ASSESSMENT FOR POSTGRADUATE CERTIFICATES 2009/10 (where offered the more favourable result of the two. Pass with Merit - 1 - #12;University of Essex Rules of Assessment

124

Fundamental Frequency Modulated Multilevel Inverter for Three-Phase Stand-Alone  

E-print Network

Fundamental Frequency Modulated Multilevel Inverter for Three-Phase Stand-Alone Photovoltaic-6472, USA Abstract - This paper presents a fundamental frequency modulated multilevel inverter scheme connected PV arrays, a five-level diode-clamped multilevel inverter (DCMLI) generating fundamental

Tolbert, Leon M.

125

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

126

Hybrid power system for a remote microwave repeater site in the Dominican Republic  

Microsoft Academic Search

The Compania Dominicana de Telefonos (CODETEL) operates several remote microwave repeater stations as a part of the Dominican Republic's microwave communications network. These repeater sites are powered by various combinations of power sources including solar photovoltaic, wind turbines, diesel generating sets, and grid-connected AC power, in both stand-alone and hybrid power system architectures. The specific hybrid power system configuration is

C. Coleman

1992-01-01

127

Deformation Mechanisms in Compression-Loaded, Stand-Alone Plasma-Sprayed Alumina Coatings  

Microsoft Academic Search

Cylindrical, stand-alone tubes of plasma-sprayed alumina were tested in compression in the axial direction at room temperature, using strain gauges to monitor axial and circum- ferential strains. The primary compression-loading profile used was cyclic loading, with monotonically increased peak stresses. Hysteresis was observed in the stress-strain response on unloading, beginning at a peak stress of 50 MPa. The modulus decreased

Rodney W. Trice; David W. Prine; K. T. Faber

2000-01-01

128

SADIST (the SAndia Data Index STructure): a stand-alone data base for computer-aided design and general use  

SciTech Connect

A file structure has been designed that fills the needs of multilevel hierarchical design of integrated circuits (ICs). Since the structure is actualized by a stand-alone FORTRAN program, it is applicable to general-purpose use in situations where the structure of the data modeled is similar to that of IC data. Though the structure itself is a FORTRAN direct-access file, its interface with user programs is a small sequential subfile accessible to FORTRAN, PASCAL, and most other languages. This ability facilitates linkup to systems already in use and requires minimal recoding. Backup, restore, and other data base recovery and integrity operations are automatic, but may be initiated by the user if desired. 3 figures.

Stauffer, J D

1980-11-01

129

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

Microsoft Academic Search

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

Tiang Tow Leong; Dahaman Ishak

2011-01-01

130

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

SciTech Connect

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

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

2006-07-01

131

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

Federal Register 2010, 2011, 2012, 2013

...Engineers Proposed Development of the Alaska Stand Alone Gas Pipeline Project (ASAP), From the North Slope to South Central Alaska, Draft Environmental Impact Statement...Mary Romero, Project Manager, Alaska District Regulatory...

2012-03-08

132

Fracture of the L-4 vertebral body after use of a stand-alone interbody fusion device in degenerative spondylolisthesis for anterior L3-4 fixation.  

PubMed

Many studies attest to the excellent results achieved using anterior lumbar interbody fusion (ALIF) for degenerative spondylolisthesis. The purpose of this report is to document a rare instance of L-4 vertebral body fracture following use of a stand-alone interbody fusion device for L3-4 ALIF. The patient, a 55-year-old man, had suffered intractable pain of the back, right buttock, and left leg for several weeks. Initial radiographs showed Grade I degenerative spondylolisthesis, with instability in the sagittal plane (upon 15° rotation) and stenosis of central and both lateral recesses at the L3-4 level. Anterior lumbar interbody fusion of the affected vertebrae was subsequently conducted using a stand-alone cage/plate system. Postoperatively, the severity of spondylolisthesis diminished, with resolution of symptoms. However, the patient returned 2 months later with both leg weakness and back pain. Plain radiographs and CT indicated device failure due to anterior fracture of the L-4 vertebral body, and the spondylolisthesis had recurred. At this point, bilateral facetectomies were performed, with reduction/fixation of L3-4 by pedicle screws. Again, degenerative spondylolisthesis improved postsurgically and symptoms eased, with eventual healing of the vertebral body fracture. This report documents a rare instance of L-4 vertebral body fracture following use of a stand-alone device for ALIF at L3-4, likely as a consequence of angular instability in degenerative spondylolisthesis. Under such conditions, additional pedicle screw fixation is advised. PMID:24725181

Kwon, Yoon-Kwang; Jang, Ju-Hee; Lee, Choon-Dae; Lee, Sang-Ho

2014-06-01

133

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

Microsoft Academic Search

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

P. Sivachandran; P. Venkatesh; N. Kamaraj

2007-01-01

134

Optimal Design of a PV/Fuel Cell Hybrid Power System for the City of Brest in France  

E-print Network

with the optimal design of a stand-alone hybrid photovoltaic and fuel cell power system without battery storage probability concept. The hybrid power system optimal design is based on a simulation model developed using. Keywords--Hybrid power system, renewable energy, fuel cell, photovoltaic, generation unit sizing, energy

Brest, Université de

135

Adverse selection and the challenges to stand-alone prescription drug insurance.  

PubMed

This paper investigates a possible predictor of adverse selection problems in unsubsidized stand-alone prescription drug insurance: the persistence of an individual's high spending over multiple years. Using Medstat claims data and data from the Medicare Survey of Current Beneficiaries, we find that persistence is much higher for outpatient drug expenses than for other categories of medical expenses. We then use these estimates to develop a simple and intuitive model of adverse selection in competitive insurance markets and show that this high relative persistence makes it unlikely that unsubsidized drug insurance can be offered for sale, even with premiums partially risk adjusted, without a probable adverse selection death spiral. We show that this outcome can be avoided if drug coverage is bundled with other coverage, and we briefly discuss the need either for comprehensive coverage or generous subsidies if adverse selection is to be avoided in private and Medicare insurance markets. PMID:15612335

Pauly, Mark V; Zeng, Yuhui

2004-01-01

136

Biomechanical comparison of three stand-alone lumbar cages -- a three-dimensional finite element analysis  

PubMed Central

Background For anterior lumbar interbody fusion (ALIF), stand-alone cages can be supplemented with vertebral plate, locking screws, or threaded cylinder to avoid the use of posterior fixation. Intuitively, the plate, screw, and cylinder aim to be embedded into the vertebral bodies to effectively immobilize the cage itself. The kinematic and mechanical effects of these integrated components on the lumbar construct have not been extensively studied. A nonlinearly lumbar finite-element model was developed and validated to investigate the biomechanical differences between three stand-alone (Latero, SynFix, and Stabilis) and SynCage-Open plus transpedicular fixation. All four cages were instrumented at the L3-4 level. Methods The lumbar models were subjected to the follower load along the lumbar column and the moment at the lumbar top to produce flexion (FL), extension (EX), left/right lateral bending (LLB, RLB), and left/right axial rotation (LAR, RAR). A 10 Nm moment was applied to obtain the six physiological motions in all models. The comparison indices included disc range of motion (ROM), facet contact force, and stresses of the annulus and implants. Results At the surgical level, the SynCage-open model supplemented with transpedicular fixation decreased ROM (>76%) greatly; while the SynFix model decreased ROM 56-72%, the Latero model decreased ROM 36-91%, in all motions as compared with the INT model. However, the Stabilis model decreased ROM slightly in extension (11%), lateral bending (21%), and axial rotation (34%). At the adjacent levels, there were no obvious differences in ROM and annulus stress among all instrumented models. Conclusions ALIF instrumentation with the Latero or SynFix cage provides an acceptable stability for clinical use without the requirement of additional posterior fixation. However, the Stabilis cage is not favored in extension and lateral bending because of insufficient stabilization. PMID:24088294

2013-01-01

137

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

138

Are integrated HIV services less stigmatizing than stand-alone models of care? A comparative case study from Swaziland  

PubMed Central

Introduction Integrating HIV with primary health services has the potential to reduce HIV-related stigma through delivering care in settings disassociated with HIV. This study investigated the relationship between integrated care and felt stigma. The study design was a comparative case study of four models of HIV care in Swaziland, ranging from fully integrated to fully stand-alone HIV care. Methods An exit survey (N=602) measured differences in felt stigma across model of care; the primary outcome “perception of HIV status exposure through clinic attendance” was analyzed using multivariable logistic regression. In-depth interviews (N=22) explored whether and how measured differences in stigma experiences were related to service integration. Results There were significant differences in perceived status exposure across models of care. After adjustment for potential confounding between sites, those at a partially integrated site and a partially stand-alone site had greater odds of perceived status exposure than those at the fully stand-alone site (aOR 3.33, 95% CI 1.98–5.60; and aOR 11.84, 95% CI 6.89–20.36, respectively). There was no difference between the fully stand-alone and the fully integrated clinic. Qualitative data suggested that many clients at HIV-only sites felt greater confidentiality knowing that those around them were positive, and support was gained from other HIV care clients. Confidentiality was maintained in various ways, even in stand-alone sites, through separate waiting areas for HIV testing and HIV treatment, and careful clinic and room labelling. Conclusions The relationship between model of care and stigma was complex, and the hypothesis that stigma is higher at stand-alone sites did not hold true in this high prevalence setting. Policy-makers should ensure that service integration does not increase stigma, in particular within partially integrated models of care. PMID:23336726

Church, Kathryn; Wringe, Alison; Fakudze, Phelele; Kikuvi, Joshua; Simelane, Dudu; Mayhew, Susannah H

2013-01-01

139

SAPT units turn-on in an interference-dominant environment. [Stand Alone Pressure Transducer  

NASA Technical Reports Server (NTRS)

A stand alone pressure transducer (SAPT) is a credit-card-sized smart pressure sensor inserted between the tile and the aluminum skin of a space shuttle. Reliably initiating the SAPT units via RF signals in a prelaunch environment is a challenging problem. Multiple-source interference may exist if more than one GSE (ground support equipment) antenna is turned on at the same time to meet the simultaneity requirement of 10 ms. A polygon model for orbiter, external tank, solid rocket booster, and tail service masts is used to simulate the prelaunch environment. Geometric optics is then applied to identify the coverage areas and the areas which are vulnerable to multipath and/or multiple-source interference. Simulation results show that the underside areas of an orbiter have incidence angles exceeding 80 deg. For multipath interference, both sides of the cargo bay areas are found to be vulnerable to a worst-case multipath loss exceeding 20 dB. Multiple-source interference areas are also identified. Mitigation methods for the coverage and interference problem are described. It is shown that multiple-source interference can be eliminated (or controlled) using the time-division-multiplexing method or the time-stamp approach.

Peng, W.-C.; Yang, C.-C.; Lichtenberg, C.

1990-01-01

140

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

EPA Science Inventory

Two types of stand-alone photolytic converters of nitrogen dioxide (NO2) to nitric oxide (NO) are now commercially available for use with NO, ozone (O3) chemiluminescence detector (CLD) monitors for the measurement of NO2. Both units have been tested for interferences resulting...

141

Psychometric Properties of the Embedded and Stand-Alone Versions of the MMPI-2 Keane PTSD Scale.  

ERIC Educational Resources Information Center

Comparability of the embedded and stand-alone versions of the Keane Postraumatic Stress Disorder Scale (T. Keane and others, 1984) of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) was supported in a study with 123 Vietnam veterans, 68 of whom were diagnosed with posttraumatic stress disorder (PTSD). (SLD)

Herman, Debra S.; Weathers, Frank W.; Litz, Brett T.; Keane, Terrence M.

1996-01-01

142

Stand-alone remotely interrogated device for the real-time health monitoring of bonded structural repairs  

NASA Astrophysics Data System (ADS)

Adhesively-bonded fiber reinforced composite patches have been used extensively, over the last two decades, on Royal Australian Air Force aircraft to repair fatigue-cracked metallic aircraft components. The bonded repair to the cracked structure - crack patching - allows the restoration of strength and stiffness to the structure, as well as slowing crack growth by reducing stress intensity. However, especially for repairs to critical components the bonded repair needs continuous health monitoring to ensure structural integrity is not compromised. The ultimate goal for very demanding repair applications is to incorporate sensor, actuators and electronics in repair systems - smart repair systems - to monitor and report on the health of the repair and the repaired structure, as well as to actuate in order to prevent damage or failure of the repaired structure. The initial focus in the development of smart repair systems is on the assessment of new sensors and instrumentation which may be incorporate in bonded repair system in order to achieve on-line measurement of patch integrity and effectiveness. This application would allow the operator to move away from current costly time-based maintenance procedures toward real-time health condition monitoring of the bonded repair and the repaired structure. These systems would allow timely decisions on preventative and schedule maintenance before failure of the repair or repaired structure. To this end a 'stand-alone' data logger device, for the real-time health monitoring of bonded repaired system, which is in lose proximity to sensors on a repair is being developed. The instrumentation will measure, process and store sensor measurements during flight and then allow this data to be down loaded, after the flight, onto a PC, via remote data access.

Galea, Stephen C.; Powlesland, Ian G.; Baker, Alan A.

1997-11-01

143

Probabilistic modeling of solar power systems  

NASA Technical Reports Server (NTRS)

The author presents a probabilistic approach based on Markov chain theory to model stand-alone photovoltaic power systems and predict their long-term service performance. The major advantage of this approach is that it allows designers and developers of these systems to analyze the system performance as well as the battery subsystem performance in the long run and determine the system design requirements that meet a specified service performance level. The methodology presented is illustrated by using data for a radio repeater system for the Boston, Massachusetts, location.

Safie, Fayssal M.

1989-01-01

144

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

DOEpatents

An illumination source is disclosed comprising a porous silicon having a source of electrons on the surface and/or interstices 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. 1 fig.

Tam, S.W.

1998-06-16

145

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

DOEpatents

Disclosed is an illumination source comprising a porous silicon having a source of electrons on the surface and/or interstices 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. 1 fig.

Tam, S.W.

1997-02-25

146

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

147

Power Systems Integration Laboratory (Fact Sheet)  

SciTech Connect

This fact sheet describes the purpose, lab specifications, applications scenarios, and information on how to partner with NREL's Power Systems Integration Laboratory at the Energy Systems Integration Facility. At NREL's Power Systems Integration Laboratory in the Energy Systems Integration Facility (ESIF), research focuses on developing and testing large-scale distributed energy systems for grid-connected, stand-alone, and microgrid applications. The laboratory can accommodate large power system components such as inverters for photovoltaic (PV) and wind systems, diesel and natural gas generators, battery packs, microgrid interconnection switchgear, and vehicles. Closely coupled with the research electrical distribution bus at the ESIF, the Power Systems Integration Laboratory will offer power testing capability of megawatt-scale DC and AC power systems, as well as advanced hardware-in-the-loop and model-in-the-loop simulation capabilities. Thermal heating and cooling loops and fuel also allow testing of combined heating/cooling and power systems (CHP).

Not Available

2011-10-01

148

Automated gas-phase purification for accurate, multiplexed quantification on a stand-alone ion trap mass spectrometer  

PubMed Central

Isobaric tagging enables the acquisition of highly-multiplexed proteome quantification but is hindered by the pervasive problem of precursor interference. The elimination of co-isolated contaminants prior to reporter tag generation can be achieved through the use of gas-phase purification via proton transfer ion/ion reactions (QuantMode); however, the original QuantMode technique was implemented on the high resolution linear ion trap-Orbitrap hybrid mass spectrometer enabled with electron transfer dissociation (ETD). Here we extend this technology to stand-alone linear ion trap systems (trapQuantMode). Facilitated by the use of inlet beam-type activation (i.e., trapHCD) for production and observation of the low mass-to-charge reporter region, this scan sequence comprises three separate events to maximize peptide identifications, minimize duty cycle requirements, and increase quantitative accuracy, precision, and dynamic range. Significant improvements in quantitative accuracy were attained over standard methods when using trapQuantMode (trapQM) to analyze an interference model system comprising tryptic peptides of yeast that we contaminated with human peptides. Finally, we demonstrate practical benefits of this method by analysis of the proteomic changes that occur during mouse skeletal muscle myoblast differentiation. While trapQM’s reduced duty cycle led to the identification of fewer proteins than conventional operation (4,050 vs. 2,964), trapQM identified more significant differences (>1.5 fold, 1,362 vs 1,132, respectively; P<0.05) between the proteomes of undifferentiated myoblasts and differentiated myotubes and nearly ten-fold more differences with changes greater than 5-fold (96 vs. 12). We further show that our trapQM dataset is superior for identifying changes in protein abundance that are consistent with the metabolic and structural changes known to accompany myotube formation. PMID:23046161

Vincent, Catherine E.; Rensvold, Jarred W.; Westphall, Michael S.; Pagliarini, David J.; Coon, Joshua J.

2012-01-01

149

The effectiveness of stand-alone cognitive-behavioural therapy for body image: A meta-analysis  

Microsoft Academic Search

This meta-analysis examined the effectiveness of stand-alone body image (BI) cognitive-behavioural therapy (CBT). Nineteen studies met inclusion criteria. The behavioural dimension of BI improves most after BI CBT while the investment dimension improves the least. Individuals with clinical BI disturbances improve more than do college student samples. Treatments addressing the attitudinal, behavioural, and perceptual components of BI are more effective

Josée L. Jarry; Karen Ip

2005-01-01

150

On the storage batteries used in solar electric power systems and development of an algorithm for determining their ampere–hour capacity  

Microsoft Academic Search

Storage batteries are indispensable in all stand alone solar electric systems (PV power systems). Their efficiencies and life times affect significantly the overall PV system performance and economics. Batteries specified especially for use in PV systems have to be distinguished with standing of very deep discharge rate and high cycling stability.Ordinary batteries being marketed world wide for use in automobile,

Marwan M. Mahmoud

2004-01-01

151

Design and control of bi-directional DC\\/DC converter for 30kW fuel cell power system  

Microsoft Academic Search

Fuel cell (FC) power system is considered as an alternative energy power generation system in the future. This paper studies the bidirectional DC\\/DC converter for a 30kW three-phase fuel cell power system. The FC power system is sensitive to load characteristics in stand-alone mode, because rapid change or unbalance of the three-phase load will endanger the safety and expectancy of

Xiao Li; Wenping Zhang; Haijin Li; Ren Xie; Dehong Xu

2011-01-01

152

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

Microsoft Academic Search

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

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

2008-01-01

153

MONITORING SYSTEM OF LARGE POWER TRANSFORMERS BASED ON UP - TO - DATE INFORMATION TECHNOLOGY  

Microsoft Academic Search

Large power transformers belong to the most valuable and important assets in electrical power systems. The ageing of the used oil\\/paper-insulation primarily depends on the hot-spot temperature of the solid insulation system. Hence it is the dominant factor limiting the lifetime of the transformer. Therefore in 1996 a prototype of a stand alone thermal monitoring system was developed and installed

Enzo CARDILLO; Kurt FESER

154

Design of stand-alone brackish water desalination wind energy system for Jordan  

Microsoft Academic Search

More than 100 underground water wells drilled in Jordan are known to have brackish water with total desolved solids (TDS) over 1500 ppm but not greater than 4000 ppm. The world standard for potable water limits the TDS count to 500 ppm in addition to being free from live microorganisms or dangerous mineral and organic substances. A reverse osmosis desalination

S. M. Habali; I. A. Saleh

1994-01-01

155

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

E-print Network

://www.satie.ens-cachan.fr ABSTRACT: Photovoltaic (PV) installations are typically optimized on the basis of simplified considerations of working on averaged time series data using much narrower time intervals (e.g. 1-hour series). Design initial outlay for an autonomous installation producing photovoltaic electricity, the design process must

Paris-Sud XI, Université de

156

Efficacy of Laparoscopic Sleeve Gastrectomy (LSG) as a Stand-Alone Technique for Children with Morbid Obesity  

Microsoft Academic Search

Background  Laparoscopic sleeve gastrectomy (LSG) is basically unknown as a stand-alone technique for bariatric surgery in children and\\u000a adolescents. It may be advantageous for this age group though, since it requires neither foreign body placement nor life-long\\u000a malabsorption. We present the first report about the efficacy of LSG in a small pediatric series.\\u000a \\u000a \\u000a \\u000a Methods  All patients (n?=?4, female) had been in a

H. Till; S. Blüher; W. Hirsch; W. Kiess

2008-01-01

157

A study on optimal sizing of stand-alone photovoltaic stations  

Microsoft Academic Search

One major application of photovoltaic (PV) power has been in remote areas as isolated small power generation for essential electric power. This paper discusses issues in optimizing the use of such stations and presents a procedure to evaluate different PV schemes considering the stochastic natures of the insolation and the load. The reliability measures in terms of loss of load

G. B. Shrestha; L. Goel

1998-01-01

158

AN ABSTRACT OF A THESIS DESIGN OF A STAND-ALONE CONTROL STRATEGY FOR  

E-print Network

of energy management. Previous research on hybrid vehicle control focused on the torque/power split between-speed characteristics. These control strategies are difficult to implement. They require a built-in controller, torque/power parents, Osman and Muzeyyen Bedir for their love and encouragement during my work. #12;v TABLE OF CONTENTS

California at Davis, University of

159

Design and performance evaluation of a unity power factor converter for wind energy conversion systems.  

E-print Network

??Wind turbine driven Permanent Magnet Synchronous Generators (PMSG) find increasing applications due to their numerous advantages. Small scale stand-alone wind energy systems are receiving considerable… (more)

Nirnaya Sarangan.

2012-01-01

160

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

161

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

162

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

163

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

164

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

165

APT - NASA ENHANCED VERSION OF AUTOMATICALLY PROGRAMMED TOOL SOFTWARE - STAND-ALONE VERSION  

NASA Technical Reports Server (NTRS)

The APT code is one of the most widely used software tools for complex numerically controlled (N/C) machining. APT is an acronym for Automatically Programmed Tools and is used to denote both a language and the computer software that processes that language. Development of the APT language and software system was begun over twenty years ago as a U. S. government sponsored industry and university research effort. APT is a "problem oriented" language that was developed for the explicit purpose of aiding the N/C machine tools. Machine-tool instructions and geometry definitions are written in the APT language to constitute a "part program." The APT part program is processed by the APT software to produce a cutter location (CL) file. This CL file may then be processed by user supplied post processors to convert the CL data into a form suitable for a particular N/C machine tool. This June, 1989 offering of the APT system represents an adaptation, with enhancements, of the public domain version of APT IV/SSX8 to the DEC VAX-11/780 for use by the Engineering Services Division of the NASA Goddard Space Flight Center. Enhancements include the super pocket feature which allows concave and convex polygon shapes of up to 40 points including shapes that overlap, that leave islands of material within the pocket, and that have one or more arcs as part of the pocket boundary. Recent modifications to APT include a rework of the POCKET subroutine and correction of an error that prevented the use within a macro of a macro variable cutter move statement combined with macro variable double check surfaces. Former modifications included the expansion of array and buffer sizes to accommodate larger part programs, and the insertion of a few user friendly error messages. The APT system software on the DEC VAX-11/780 is organized into two separate programs: the load complex and the APT processor. The load complex handles the table initiation phase and is usually only run when changes to the APT processor capabilities are made. This phase initializes character recognition and syntax tables for the APT processor by creating FORTRAN block data programs. The APT processor consists of four components: the translator, the execution complex, the subroutine library, and the CL editor. The translator examines each APT statement in the part program for recognizable structure and generates a new statement, or series of statements, in an intermediate language. The execution complex processes all of the definition, motion, and related statements to generate cutter location coordinates. The subroutine library contains routines defining the algorithms required to process the sequenced list of intermediate language commands generated by the translator. The CL editor re-processes the cutter location coordinates according to user supplied commands to generate a final CL file. A sample post processor is also included which translates a CL file into a form for use with a Wales Strippit Fabramatic Model 30/30 sheet metal punch. The user should be able to readily develop post processors for other N/C machine tools. The APT language is a statement oriented, sequence dependent language. With the exception of such programming techniques as looping and macros, statements in an APT program are executed in a strict first-to-last sequence. In order to provide programming capability for the broadest possible range of parts and of machine tools, APT input (and output) is generalized, as represented by 3-dimensional geometry and tools, and arbitrarily uniform, as represented by the moving tool concept and output data in absolute coordinates. A command procedure allows the user to select the desired part program, ask for a graphics file of cutter motions in IGES format, and submit the procedure as a batch job, if desired. The APT system software is written in FORTRAN 77 for batch and interactive execution and has been implemented on a DEC VAX series computer under VMS 4.4. The enhancements for this version of APT were last updated in June, 1989. The NASA adaptat

Premo, D. A.

1994-01-01

166

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

167

Stress Relaxation of Compression Loaded Plasma-Sprayed 7 Wt% Y2O3ZrO2 Stand-Alone Coatings  

E-print Network

. Introduction PLASMA-SPRAYED thermal barrier coatings (TBCs) are used as protective coatings in high these coatings during service. Due to the low thermal conductivity of the YSZ as compared with the metallicStress Relaxation of Compression Loaded Plasma-Sprayed 7 Wt% Y2O3­ZrO2 Stand-Alone Coatings Graeme

Trice, Rodney W.

168

Power conditioning: The link between solar conversion and consumer  

Microsoft Academic Search

The power conditioning for two forms of renewable energy, wind and photovoltaics (PV) links electric power generation to the consumer with requirements that provide the main control inputs for the power flow. In addition to the coupling of PV and wind energy plants to existing grids, stand-alone systems are described. The latter offer early potential for market introduction of renewable

S. Heier; W. Kleinkauf; J. Sachau

1994-01-01

169

A technique for power supply harmonic impedance estimation using a controlled voltage disturbance  

Microsoft Academic Search

A method for power system impedance estimation is presented. The method employs a power converter to inject a voltage transient onto the supply system. As the technique employs controlled power electronic devices it may be used as a stand alone piece of a portable measurement equipment, or it may be embedded into the functions of an active shunt filter for

Mark Sumner; Ben Palethorpe; David W. P. Thomas; Pericle Zanchetta; Maria Carmela Di Piazza

2002-01-01

170

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

171

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

172

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

173

A PC-PCL-based control system for the high-voltage pulsed-power operation of the Intense Diagnostic Neutral Beam (IDNB) Experiment  

SciTech Connect

A stand-alone, semiautomated control system for the high-voltage pulsed-power energy sources on the Intense Diagnostic Neutral Beam Experiment at Los Alamos National Laboratory using personal computer (PC) and programmable logic controller (PLC) technology has been developed and implemented. The control system, consisting of a PC with the graphic operator interface, the network connecting the PC to the PLC, the PLC, the PLC I/O modules, fiber-optic interfaces and software, is described.

Gribble, R.

1993-06-01

174

Development of a fuel cell power conditioner system  

Microsoft Academic Search

The fuel cell is an alternative power generation method which is envisaged to be environmentally friendly and efficient. It can be an attractive solution for various “clean power” applications such as an electric vehicle. It can also be suitably used as a stand alone power generator. The fuel cell converts chemical energy into electrical energy by means of an electrochemical

K. M. Salim; Zainal Salam; Faridah Taha; A. H. M. Yatim

1999-01-01

175

Ris-R-1219(EN) / SEC-R-12 Models for a Stand-Alone PV System  

E-print Network

.3 Battery model validation 37 6.4 Controller model validation 56 6.5 Inverter model validation 57 7 Dynamic to the KiBaM model. A validation of each of the implemented mathematical model is performed Measurement results and model validation 29 6.1 General on measurements 29 6.2 PV model validation 32 6

176

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.

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

2014-01-01

177

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

178

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

179

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

Microsoft Academic Search

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

Fawzi Banat; Nesreen Jwaied

2008-01-01

180

Management of in-stent restenosis in peripheral arteries: are DEBs sufficient as stand-alone treatment for femoro-popliteal in-stent restenosis?  

PubMed

The treatment of in-stent restenosis (ISR) in the femoro-popliteal artery (FPA) is one of the major challenges of endovascular therapy, occurring in up to 40% of femoro-popliteal lesions treated with bare-metal stents within 1 year of treatment. Drug-eluting technologies, involving local delivery of paclitaxel, are providing a new paradigm for the treatment of ISR. Preliminary experience shows promising results compared to other techniques such as cutting balloon angioplasty and debulking strategies. Based on available data, drug-eluting balloons (DEBs) seem sufficient as stand-alone treatment of FPA-ISR. However, larger evidence from randomized studies is warranted to identify the clinical and/or anatomical setting in which they could fail. PMID:24755701

Franzone, A; Stabile, E; Carbone, A; Scudiero, F; Trimarco, B; Esposito, G

2014-06-01

181

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

182

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

183

Power system  

DOEpatents

A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

Hickam, Christopher Dale (Glasford, IL)

2008-03-18

184

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

185

A novel solid state voltage controller of three phase Self Excited Induction Generator for decentralized power generation  

Microsoft Academic Search

This paper presents a simple control structure for the stand alone operation of Self Excited Induction Generator used to operate under variable loads. The proposed system uses PWM Voltage Source Inverter, DC-DC Boost Converter and diode bridge Rectifier with SEIG. The required reactive power for the Self Excited Induction Generator is supplied by means of a capacitor bank and the

S. S. Murthy; R. K. Ahuja

2010-01-01

186

Design and evaluation of a PWM rectifier control system for testing renewable DC sources connected to the grid  

Microsoft Academic Search

Voltage source PWM rectifiers connected to the AC grid are increasingly used in different applications like stand alone power supplies, high-efficiency regenerative AC drives and grid-connected renewable energies. Fast dynamics, sinusoidal input current, and unity power factor justify its wide application. The overall system performance is strongly dependent on the PWM rectifier characteristics. The main performance indices are related to

N. Silva; A. Martins; A. Carvalho

2006-01-01

187

Study on Cosmic Ray Background Rejection with a 30 m Stand-Alone IACT using Non-parametric Multivariate Methods in a sub-100 GeV Energy Range  

E-print Network

During the last decade ground-based very high-energy gamma-ray astronomy achieved a remarkable advancement in the development of the observational technique for the registration and study of gamma-ray emission above 100 GeV. It is widely believed that the next step in its future development will be the construction of telescopes of substantially larger size than the currently used 10 m class telescopes. This can drastically improve the sensitivity of the ground-based detectors for gamma rays of energy from 10 to 100 GeV. Based on Monte Carlo simulations of the response of a single stand-alone 30 m imaging atmospheric Cherenkov telescope (IACT) the maximal rejection power against background cosmic ray showers for low energy gamma-rays was investigated in great detail. An advanced Bayesian multivariate analysis has been applied to the simulated Cherenkov light images of the gamma-ray- and proton-induced air showers. The results obtained here quantitatively testify that the separation between the signal and background images degrades substantially at low energies, and consequently the maximum overall quality factor can only be about 3.1 for gamma rays in the 10-30 GeV energy range. Various selection criteria as well as optimal combinations of the standard image parameters utilized for effective image separation have been also evaluated.

A. Konopelko; A. Chilingarian; A. Reimers

2006-11-29

188

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

189

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

190

EXPANDABLE HYBRID SYSTEMS FOR MULTI-USER MINI-GRIDS  

Microsoft Academic Search

Village electrification represents a high potential market for hybrid power systems. Many stand-alone diesel units are powering mini-grids all around the world and could be retrofitted with renewable power generators and battery storage units. Small hybrid power systems have proven to be a cost-effective solution for powering single user applications. However, in the case of multi-user mini-grids, there is a

Michel Vandenbergh; Sascha Beverungen; Britta Buchholz; Hervé Colin; Nipon Ketjoy; Franz Kininger; Didier Mayer; Jens Merten; Jürgen Reekers; Philipp Strauss

191

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

Microsoft Academic Search

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

Pragya Nema; R. K. Nema; Saroj Rangnekar

2010-01-01

192

An innovative stand-alone bioreactor for the highly reproducible transfer of cyclic mechanical stretch to stem cells cultured in a 3D scaffold.  

PubMed

Much evidence in the literature demonstrates the effect of cyclic mechanical stretch in maintaining, or addressing, a muscle phenotype. Such results were obtained using several technical approaches, useful for the experimental collection of proofs of principle but probably unsuitable for application in clinical regenerative medicine. Here we aimed to design a reliable innovative bioreactor, acting as a stand-alone cell culture incubator, easy to operate and effective in addressing mesenchymal stem cells (MSCs) seeded onto a 3D bioreabsorbable scaffold, towards a muscle phenotype via the transfer of a controlled and highly-reproducible cyclic deformation. Electron microscopy, immunohistochemistry and biochemical analysis of the obtained pseudotissue constructs showed that cells 'trained' over 1?week: (a) displayed multilayer organization and invaded the 3D mesh of the scaffold; and (b) expressed typical markers of muscle cells. This effect was due only to physical stimulation of the cells, without the need of any other chemical or genetic manipulation. This device is thus proposed as a prototypal instrument to obtain pseudotissue constructs to test in cardiovascular regenerative medicine, using good manufacturing procedures. Copyright © 2012 John Wiley & Sons, Ltd. PMID:22865609

Govoni, Marco; Lotti, Fabrizio; Biagiotti, Luigi; Lannocca, Maurizio; Pasquinelli, Gianandrea; Valente, Sabrina; Muscari, Claudio; Bonafè, Francesca; Caldarera, Claudio M; Guarnieri, Carlo; Cavalcanti, Silvio; Giordano, Emanuele

2014-10-01

193

Utility-interactive multi-functional bidirectional converter for solar photovoltaic power conditioner with energy storage batteries  

Microsoft Academic Search

This paper presents a bidirectional power conditioner based on a solar photovoltaic panel and storage battery bank. The power processing system implementation incorporating a multi-functional control strategy introduced as switching mode schemes between stand-alone and utility-interactive operations is also discussed. Furthermore, experimental results tested through a 3 kVA prototype power conditioner using PV power systems and their effectivenesses are illustrated

K. Hirachi; T. Mii; T. Nakashiba; K. G. D. Laknath; M. Nakaoka

1996-01-01

194

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

Microsoft Academic Search

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

Bogdan S. Borowy; Ziyad M. Salameh

1994-01-01

195

A stand-alone mesoporous crystal structure model from in situ X-ray diffraction: nitrogen adsorption on 3D cagelike mesoporous silica SBA-16.  

PubMed

We present a modeling scheme to analyze cagelike silica mesoporous crystals based on in situ X-ray diffraction (XRD) data collected during gas adsorption-desorption (physisorption) processes. Nitrogen physisorption on a silica mesoporous crystal of SBA-16 was directly monitored by using synchrotron in situ powder XRD measurements conducted at SPring-8. SBA-16 is a well-ordered mesoporous silica in which three-dimensional interconnected cagelike primary mesopores are located at the body-centered cubic lattice points. In addition, the surrounding silica matrix contains random microporous and mesoporous intrawall porosities that are significantly influential to the diffusion properties, and thus important to be quantified for this media. The in situ XRD data exhibits seven Bragg reflections throughout the measurements, and the present method allows one to obtain the maximal and stand-alone information about the pore structure (for example, the mesopore size, the matrix density, the intrawall porosity, and pore surface roughness) together with the nitrogen film evolution in the primary mesopores and the intrawall pore-filling in the silica matrix. We furthermore observe a macroscopic amount of nitrogen adsorbed assuming the density of the fluid, and confirm that the XRD "isotherm" recalculated from the analysis result is consistent with the conventional nitrogen isotherm on a semi-quantitative level; however, these results suggest that the intrawall pores would have a greater contribution to the adsorption than considered based on the conventional isotherm analyses. The present method is readily extendable to any ordered mesopores wrapped by the wall matrix containing a certain intrawall porosity. PMID:22829334

Miyasaka, Keiichi; Hano, Hiroko; Kubota, Yoshiki; Lin, Yangzheng; Ryoo, Ryong; Takata, Masaki; Kitagawa, Susumu; Neimark, Alexander V; Terasaki, Osamu

2012-08-13

196

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

NASA Astrophysics Data System (ADS)

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

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

1981-04-01

197

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

198

Market assessment of photovoltaic power systems for agricultural applications worldwide  

NASA Technical Reports Server (NTRS)

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.

1981-01-01

199

Recurrent Functional-Link-Based Fuzzy-Neural-Network-Controlled Induction-Generator System Using Improved Particle Swarm Optimization  

Microsoft Academic Search

A recurrent functional-link (FL)-based fuzzy-neural-network (FNN) controller with improved particle swarm optimization (IPSO) is proposed in this paper to control a three-phase induction-generator (IG) system for stand-alone power application. First, an indirect field-oriented mechanism is implemented for the control of the IG. Then, an AC\\/DC power converter and a DC\\/AC power inverter are developed to convert the electric power generated

Faa-Jeng Lin; Li-Tao Teng; Jeng-Wen Lin; Syuan-Yi Chen

2009-01-01

200

Performance characteristics of solar-photovoltaic flywheel-storage systems  

SciTech Connect

A solar photovoltaic energy flywheel storage and conversion system for residential applications was designed, built and tested. Performance and efficiency measurements were conducted on the system, which utilizes low-loss magnetic bearings, maximum-power-point tracking of the photovoltaic array, integrated permanent magnet motor-generator, and output power-conditioning sections of either the stand-alone cycloconverter or utility interactive inverter type. The overall in-out electrical storage efficiency of the flywheel system was measured along with the power transfer efficiencies of the individual components and the system spin-down tare losses. A round-trip storage efficiency of 82% in the utility interactive mode and 74% in the stand-alone mode was found. This compares favorably with systems involving batteries and an inverter, which typically exhibit a round trip efficiency less than 70%.

Jarvinen, P. O.; Brench, B. L.; Rasmussen, N. E.

1981-01-01

201

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

Microsoft Academic Search

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

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

2010-01-01

202

Waste Heat Recovery Power Generation with WOWGen  

E-print Network

(pipeline compression stations, processing plants). Sources such as stack flue gases, steam, diesel exhaust, hot oil or combinations of sources can be used to generate power. WOWGen® can also be used with stand alone power plants burning fossil fuels...

Romero, M.

203

Surgical Outcome of a Zero-profile Device Comparing with Stand-alone Cage and Anterior Cervical Plate with Iliac Bone Graft in the Anterior Cervical Discectomy and Fusion  

PubMed Central

Objective A Zero-profile device is a cervical stand-alone cage with integrated segmental fixation device. We characteristically evaluated the radiological changes as well as clinical outcomes in the application of Zero-profile devices compared with stand-alone cages and anterior cervical plates with iliac bone grafts for the cervical disease. Methods Retrospectively, total 60 patients at least more than one year follow-up were enrolled. Twenty patients were treated with Zero-profile devices (Group A), twenty patients with stand-alone cages (Group B) and twenty patients with anterior cervical plates and iliac bone grafts (Group C) for a single level cervical disease. The clinical outcomes were evaluated by Odom's criteria and Bazaz-Yoo dysphagia index. The radiologic parameters were by subsidence and the changes of the midpoint interbody height (IBH), the segmental kyphotic angle (SKA), the overall kyphotic angle (OKA) in index level. Results Although there was no significant clinical difference according to the Odom's criteria among them(p=0.766), post-operative dysphagia was significantly decreased in the Group A and B compared with the Group C (p=0.04). From the immediate postoperative to the last follow-up time, the mean change of IBH decrement and SKA increment were significant in the Group B compared with the Group A (p=0.025, p=0.033) and the Group C (p=0.001, p=0.000). The subsidence rate was not significant among all groups (p=0.338). Conclusion This Zero-profile device is a valuable alternative to the anterior cervical discectomy and fusion with a low incidence of postoperative dysphagia and without segmental kyphotic change. PMID:25346764

Shin, Jae Sik; Cho, Pyoung Goo

2014-01-01

204

Minimally invasive lateral transpsoas interbody fusion using a stand-alone construct for the treatment of adjacent segment disease of the lumbar spine: review of the literature and report of three cases.  

PubMed

We describe 3 patients who presented with radiographic signs and clinical symptoms of adjacent segment disease several years after undergoing L4-S1 posterior pedicle screw fusion. All patients underwent successful lateral lumbar interbody fusion (LLIF) at 1-2 levels above their previous constructs, using stand-alone cages, with complete resolution of radiculopathy and a significant improvement in low-back pain. In addition to a thorough analysis of these cases, we review the pertinent literature regarding treatment options for adjacent segment disease and the applications of the lateral lumbar interbody technique. PMID:25019458

Palejwala, Sheri K; Sheen, Whitney A; Walter, Christina M; Dunn, Jack H; Baaj, Ali A

2014-09-01

205

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

Microsoft Academic Search

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

Yea-Kuang Chan; Jyh-Cherng Gu

2011-01-01

206

How Britain changed from public to private power emdash overnight  

SciTech Connect

This paper reports that privatization will bring real competition to the electric power industry in Britain, according to Robert Malpas, chairman of PowerGen, one of the country's new private generating companies. The customer will be king, he believes. John Baker, chief executive of National Power (another generating company), says, A system in which power generation was essentially a monopoly activity operated and controlled through an integrated transmission system, has been changed virtually overnight into a competitive and desegregated industry in which generation is primarily a stand-alone activity.

Smith, D.J.

1991-06-01

207

A Pneumatic System for Capturing and Storing Wind Energy in Egypt  

Microsoft Academic Search

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

E. M. ElBeheiry

2011-01-01

208

Design, Fabrication and Certification of Advanced Modular PV Power Systems  

NASA Astrophysics Data System (ADS)

The Design, Fabrication and Certification of Advanced Modular PV Power Systems contract is a Photovoltaic Manufacturing Technology (PVMaT) cost-shared contract under Phase 4A1 for Product Driven Systems and Component Technologies. Phase 4A1 has the goals to improve the cost-effectiveness and manufacturing efficiency of PV end-products, optimize manufacturing and packaging methods, and generally improve balance-of-system performance, integration and manufacturing. This contract has the specific goal to reduce the installed PV system life cycle costs to the customer with the ultimate goal of increasing PV system marketability and customer acceptance. The specific objectives of the project are to develop certified, standardized, modular, pre-engineered products lines of our main stand-alone systems, the Modular Autonomous PV Power Supply (MAPPS) and PV-Generator Hybrid System (Photogenset). To date, we have designed a 200 W MAPPS and a 1 kW Photogenset and are in the process of having the MAPPS certified by Underwriters Laboratories (UL Listed) and approved for hazardous locations by Factory Mutual (FM). We have also developed a manufacturing plan for product line expansion for the MAPPS. The Photogenset will be fabricated in February 1997 and will also be UL Listed. Functionality testing will be performed at NREL and Sandia with the intentions of providing verification of performance and reliability and of developing test-based performance specifications. In addition to an expansion on the goals, objectives and status of the project, specific accomplishments and benefits are also presented in this paper.

Minyard, Glen E.; Lambarski, Timothy J.

1997-02-01

209

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

210

[Application of a stand-alone interbody fusion cage based on a novel porous TiO2/glass ceramic--2: Biomechanical evaluation after implantation in the sheep cervical spine].  

PubMed

Animals are becoming more and more common as in vivo models for the human spine. Especially the sheep cervical spine is stated to be of good comparability and usefulness in the evaluation of in vivo radiological, biomechanical and histological behaviour of new bone replacement materials, implants and cages for cervical spine interbody fusion. In preceding biomechanical in vitro examinations human cervical spine specimens were tested after fusion with either a cubical stand-alone interbody fusion cage manufactured from a new porous TiO2/glass composite (Ecopore) or polymethylmethacrylate (PMMA) after discectomy. Following our first experience with the use of the new material and its influence on the primary stability after in vitro application we carried out fusions of 20 sheep cervical spines levels with either PMMA or an Ecopore-cage, and performed radiological examinations during the following 2-4 months. In this second part of the study we intended the biomechanical evaluation of the spine segments with reference to the previously determined morphological findings, like subsidence of the implants, significant increase of the kyphosis angle and degree of the bony fusion along with the interpretation of the results. 20 sheep cervical spines segments with either PMMA- or Ecopore-fusion in the levels C2/3 and C4/5 were tested, in comparison to 10 native corresponding sheep cervical spine segments. Non-destructive biomechanical testing was performed, including flexion/extension, lateral bending and axial rotation using a spine testing apparatus. Three-dimensional range of motion (ROM) was evaluated using an ultrasound measurement system. In the native spine segments C2/3 and C4/5 the ROM increased in cranio-caudal direction particulary in flexion/extension, less pronounced in lateral flexion and axial rotation (p < 0.05). The overall ROM of both tested segments was greatest in lateral flexion, reduced to 52% in flexion/extension and to 16% in axial rotation. After 2 months C2/3- and C4/5-segments with PMMA-fusion and C2/3-segments with Ecopore-interposition showed decrease of ROM in lateral flexion in comparison to the native segments, indicating increasing stiffening. However, after 4 months all operated segments, independent from level or implanted material, were stiffer than the comparable native segments. The decrease of the ROM correlated with the radiological-morphological degree of fusion. Our evaluation of the new porous TiO2/glass composite as interbody fusion cage has shown satisfactory radiological results as well as distinct biomechanical stability and fusion of the segments after 4 months in comparison to PMMA. After histological analysis of the bone-biomaterial-interface, further examinations of this biomaterial previous to an application as alternative to other customary cages in humans are necessary. PMID:15884708

Korinth, M C; Hero, T; Pandorf, T; Zell, D

2005-04-01

211

Solar power system  

Microsoft Academic Search

Various control methods and means are disclosed for varying the temperature of vaporization of a solar-powered system so that the instantaneous power delivered by the heat engine of this system, or by a device driven by this engine, is a maximum for given conditions external to the power system, or to the power system and the driven device, respectively, while

Molivadas

1982-01-01

212

Development of small embedded GPS/INS RLG and FOG systems for the 90's and beyond  

NASA Astrophysics Data System (ADS)

An account is given of the advantages of an embedded Integrated GPS/INS (IGI) system, in light of overall mission flexibility, over a closely-coupled GPS/INS system. The IGI package is smaller, lighter, less power-consuming, and less costly than stand-alone GPS and INS. Attention is given to the cases of an existing IGI ring-laser gyro with six-channel GPS and a next-generation interferometric ring-laser gyro system.

Franklin, Marty; Pagnucco, Steve

213

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

214

Stress-Relaxation and Creep Behavior of Heat-Treated Stand-Alone Plasma-Sprayed 7 wt.% Y2O3-ZrO2 Coatings  

E-print Network

Thermal barrier coatings have significantly increased the working efficiency of turbine engine and diesel engine systems. The basic thermal barrier coating system is made up of the metal substrate, a bond coat Coatings C.A. Petorak, K.J. Bowman, and R.W. Trice School of Materials Engineering, Purdue University, West

Trice, Rodney W.

215

Naval shipboard power system  

Microsoft Academic Search

Different naval shipboard power system architectures and their basic characteristics have been discussed in the paper. In addition the paper discusses about incorporation of platform management systems into the ship automation system that would enable monitoring and control of the shipboard power system, assessing and diagnosing system failures\\/damages and reconfiguring and restoring power to service loads with reduced manpower and

R. Jayabalan; B. Fahimi

2005-01-01

216

Abstract--This paper presents novel Global Navigation Satellite System (GNSS)-based flight inspection systems  

E-print Network

, and integrity. The GNSS-based FIS are the WAAS-based FIS and the stand-alone GPS-based FIS. These GNSS-based FIS requires raw GPS/WAAS measurements, and the stand-alone GPS requires only raw GPS measurements. Both systems require a radar altimeter and a TeleVision Positioning System (TVPS) for CAT II and III

Stanford University

217

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

218

Electrical power generating system  

NASA Astrophysics Data System (ADS)

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

Nola, F. J.

1981-03-01

219

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

Microsoft Academic Search

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

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

2010-01-01

220

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

221

Concept of a Stand-Alone Muon Trigger with High Transverse Momentum Resolution for the ATLAS Detector at the High-Luminosity LHC  

E-print Network

The ATLAS trigger uses a three-level trigger system. The level-1 (L1) trigger for muons with high transverse momentum pT in ATLAS is based on fast chambers with excellent time resolution which are able to identify muons coming from a particular beam crossing. These trigger chambers also provide a fast measurement of the muon transverse momenta, however with limited accuracy caused by the moderate spatial resolution along the deflecting direction of the magnetic field. The higher luminosity foreseen for Phase-II puts stringent limits on the L1 trigger rates. A way to control these rates is the improvement of the spatial resolution of the triggering device which drastically sharpens the turn-on curve of the L1 trigger. To do this, the precision tracking chambers (MDT) can be used in the L1 trigger, if the corresponding trigger latency is increased as planned. The trigger rate reduction is accomplished by strongly decreasing the rate of triggers from muons with pT lower than a predefined threshold (typically 20 ...

Horii, Yasuyuki; The ATLAS collaboration

2014-01-01

222

Modelling and simulation of a PV-inverter-asychronous motor association in photovoltaic pumping systems  

Microsoft Academic Search

In this paper, we introduce a method of control and sizing of photovoltaic systems in stand alone PV pumping plants. This approach is based on the dynamic model of the PV-DC\\/DC inverter-asynchronous motor. The DC-DC converter ensures an impedance adaptation between the PV and the load and an optimal PV panel output power extraction. However, the DC\\/AC converter ensures a

C. Adnene; J. Moncef

2001-01-01

223

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

224

Brackish water desalination by a hybrid forward osmosis–nanofiltration system using divalent draw solute  

Microsoft Academic Search

In the last decade osmotically driven membrane processes have attracted growing interest in wastewater treatment, desalination and power generation. A hybrid forward osmosis–nanofiltration (FO–NF) system designed for brackish water desalination was systematically investigated in this study. The hybrid FO–NF process was also compared with a stand-alone reverse osmosis (RO) process in brackish water desalination. It is found that the hybrid

Shuaifei Zhao; Linda Zou; Dennis Mulcahy

225

Power Plant Systems Analysis  

NASA Technical Reports Server (NTRS)

Three basic thermodynamic cycles of advanced nuclear MHD power plant systems are studied. The effect of reactor exit temperature and space radiator temperature on the overall thermal efficiency of a regenerative turbine compressor power plant system is shown. The effect of MHD pressure ratio on plant efficiency is also described, along with the dependence of MHD power output, compressor power requirement, turbine power output, mass flow rate of H2, and overall plant efficiency on the reactor exit temperature for a specific configuration.

Williams, J. R.; Yang, Y. Y.

1973-01-01

226

Stand alone biofuel production from algae  

Microsoft Academic Search

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

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

2011-01-01

227

Diagnosis: genetic testing cannot stand alone.  

PubMed

Genetic testing uses advanced laboratory techniques to identify protein alterations, certain metabolites, chromosomes, or nucleic acids by which a genotype is determined or inferred. These tests provide insights into the molecular basis and physiopathology of genetic diseases, information which is critical for prevention, treatment and genetic counseling. Initiated in 1982, Cuba's National Program for Diagnosis, Management and Prevention of Birth Defects and Hereditary Diseases ensures availability of genetic tests to all Cubans who need them, free of charge, assisting physician-patient decisions. The tests may be used to confirm diagnoses, point to hereditary diseases and potential congenital problems during pregnancy or in pre-symptomatic stages, and diagnose carriers of recessive diseases. PMID:25208125

Morales-Peralta, Estela

2014-01-01

228

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

SciTech Connect

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

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

1998-10-01

229

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

230

Space station power system  

NASA Technical Reports Server (NTRS)

The major requirements and guidelines that affect the space station configuration and 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 are described and linked to the present concept. Trade study selections of photovoltaic system technologies are described in detail. A summary of present solar dynamic and power management and distribution systems is also given.

Baraona, Cosmo R.

1987-01-01

231

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

232

Power system commonality study  

NASA Astrophysics Data System (ADS)

A limited top level study was completed to determine the commonality of power system/subsystem concepts within potential lunar and Mars surface power system architectures. A list of power system concepts with high commonality was developed which can be used to synthesize power system architectures which minimize development cost. Examples of potential high commonality power system architectures are given in this report along with a mass comparison. Other criteria such as life cycle cost (which includes transportation cost), reliability, safety, risk, and operability should be used in future, more detailed studies to select optimum power system architectures. Nineteen potential power system concepts were identified and evaluated for planetary surface applications including photovoltaic arrays with energy storage, isotope, and nuclear power systems. A top level environmental factors study was completed to assess environmental impacts on the identified power system concepts for both lunar and Mars applications. Potential power system design solutions for commonality between Mars and lunar applications were identified. Isotope, photovoltaic array (PVA), regenerative fuel cell (RFC), stainless steel liquid-metal cooled reactors (less than 1033 K maximum) with dynamic converters, and in-core thermionic reactor systems were found suitable for both lunar and Mars environments. The use of SP-100 thermoelectric (TE) and SP-100 dynamic power systems in a vacuum enclosure may also be possible for Mars applications although several issues need to be investigated further (potential single point failure of enclosure, mass penalty of enclosure and active pumping system, additional installation time and complexity). There are also technical issues involved with development of thermionic reactors (life, serviceability, and adaptability to other power conversion units). Additional studies are required to determine the optimum reactor concept for Mars applications. Various screening criteria (availability, environmental compatibility, mass competitiveness of energy storage, safety, and practicality for the application) were used to define concept applicability for each lunar and Mars application. A screening study resulted in 13 power systems for lunar applications and 15 for Mars applications. A commonality analysis showed several power systems with potentially high commonality (across both lunar and Mars applications). These high commonality systems include d PVA/RFC, dynamic isotope (1033 K Stirling, 1133 K Brayton, and 1300 K Brayton PCU's), SP-100 TE and dynamic derivatives (Mars systems required vacuum enclosure), in-core thermionic reactor, and liquid metal cooled reactor/Stirling cycle (1033 K). The generic commonality results were used to synthesize 3 high commonality power system architectures: (1) predominantly PV (limited nuclear and isotope), (2) predominantly in-core thermionic reactor/DIPS, and (3) predominantly SP-100 reactor/DIPS. The in-core thermionic reactor/DIPS power system architecture had the lowest total mass. Specific outputs from this study included lists of power system requirements, power system candidates, a power system application matrix, power system characteristics (mass), power system commonality ratings, example high commonality power system architectures, architecture masses, and issues/design solutions for lunar/Mars commonality.

Littman, Franklin D.

1992-07-01

233

Residential photovoltaic flywheel storage system performance and cost  

SciTech Connect

A subscale prototype of a flywheel energy storage and conversion system for use with photovoltaic power systems of residential and intermediate load-center size has been designed, built and tested by MIT Lincoln Laboratory. System design, including details of such key components as magnetic bearings, motor generator, and power-conditioning electronics, are described. Performance results of prototype testing are given and indicate that this system is the equal of or superior to battery and inverter systems for the same application. Results of cost and user-worth analysis show that residential systems are economically feasible in stand-alone and in utility-interactive applications.

Hay, R.D.; Millner, A.R.; Jarvinen, P.O.

1980-01-01

234

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

235

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

236

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

237

Electrical power generating system  

NASA Astrophysics Data System (ADS)

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

Nola, F. J.

1983-06-01

238

Electrical power generating system  

NASA Technical Reports Server (NTRS)

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

Nola, F. J. (inventor)

1983-01-01

239

Crowd-powered systems  

E-print Network

Crowd-powered systems combine computation with human intelligence, drawn from large groups of people connecting and coordinating online. These hybrid systems enable applications and experiences that neither crowds nor ...

Bernstein, Michael Scott

2012-01-01

240

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

241

Laboratory evaluation of a pilot cell battery protection system for photovoltaic applications  

NASA Technical Reports Server (NTRS)

An energy storage method for the 3.5 kW battery power system was investigated. The Pilot Cell Battery Protection System was tested for use in photovoltaic power systems and results show that this is a viable method of storage battery control. The method of limiting battery depth of discharge has the following advantages: (1) temperature sensitivity; (2) rate sensitivity; and (3) state of charge indication. The pilot cell concept is of interest in remote stand alone photovoltaic power systems. The battery can be protected from damaging overdischarge by using the proper ratio of pilot cell capacities to main battery capacity.

Cataldo, R. L.; Thomas, R. D.

1981-01-01

242

Power Electronic Devices in Modern Power Systems  

Microsoft Academic Search

There are two main trends in present development of power systems. First is a wide utilization of renewable power resources. The second is decentralization of power generation. Hence, small power sources, very often RES sources, called dissipated power generators are developed. They are usually in range of megawatts starting form kilowatts. They operate automatically and are remotely controlled. In fact

P. Biczel; A. Jasinski; J. Lachecki

2007-01-01

243

Autonomous power expert system  

NASA Technical Reports Server (NTRS)

The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control technologies to the Space Station Freedom Electrical Power Systems (SSF/EPS). The objectives of the program are to establish artificial intelligence/expert system technology paths, to create knowledge based tools with advanced human-operator interfaces, and to integrate and interface knowledge-based and conventional control schemes. This program is being developed at the NASA-Lewis. The APS Brassboard represents a subset of a 20 KHz Space Station Power Management And Distribution (PMAD) testbed. A distributed control scheme is used to manage multiple levels of computers and switchgear. The brassboard is comprised of a set of intelligent switchgear used to effectively switch power from the sources to the loads. The Autonomous Power Expert System (APEX) portion of the APS program integrates a knowledge based fault diagnostic system, a power resource scheduler, and an interface to the APS Brassboard. The system includes knowledge bases for system diagnostics, fault detection and isolation, and recommended actions. The scheduler autonomously assigns start times to the attached loads based on temporal and power constraints. The scheduler is able to work in a near real time environment for both scheduling and dynamic replanning.

Ringer, Mark J.; Quinn, Todd M.

1990-01-01

244

Performance testing and economic analysis of a photovoltaic flywheel energy storage and conversion system  

SciTech Connect

A subscale prototype of a flywheel energy storage and conversion system for use with photovoltaic power systems of residential and intermediate load-center size has been designed, built and tested by MIT Lincoln Laboratory. System design, including details of such key components as magnetic bearings, motor generator, and power conditioning electronics, is described. Performance results of prototype testing are given and indicate that this system is the equal of or superior to battery-inverter systems for the same application. Results of cost and user-worth analysis show that residential systems are economically feasible in stand-alone and in some utility-interactive applications.

Hay, R.D.; Millner, A.R.; Jarvinen, P.O.

1980-01-01

245

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

246

Evolution of a Medical School Library Circulation System from a Batch to an Online System  

PubMed Central

The circulation system at the Health Sciences Library, George Washington University Medical Center has evolved from a stand alone batch process to an online system which is integrated into an automated library system called HAL (Himmelfarb Automated Library-System).

Larson, Robert H.

1982-01-01

247

NSTX Electrical Power Systems  

SciTech Connect

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

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

1999-12-16

248

Evolution of space power systems  

NASA Technical Reports Server (NTRS)

NASA planning for large power systems (tens to hundreds of kilowatts) in space for the next decade is summarized. Applications requiring large amounts of power, the selection of solar photovoltaic as the primary power conversion approach, and the power technology base are explained. Large power systems, beginning with a Space Shuttle/Spacelab power augmentation kit and an orbitally stored Power Module, are described.

Freitag, R. F.; Kisko, W. A.

1978-01-01

249

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

250

[Application of a stand-alone interbody fusion cage based on a novel porous TiO2/glass composite. I. Implantation in the sheep cervical spine and radiological evaluation].  

PubMed

Animals are becoming more and more common as in vitro and in vivo models for the human spine. Especially the sheep cervical spine is stated to be of good comparability and usefulness in the evaluation of in vivo radiological, biomechanical and histological behaviour of new bone replacement materials, implants and cages for cervical spine interbody fusion. In preceding biomechanical in vitro examination human cervical spine specimens were tested after fusion with either a cubical stand-alone interbody fusion cage manufactured from a new porous TiO/glass composite (Ecopore) or polymethyl-methacrylate (PMMA) after discectomy. First experience with the use of the new material and its influence on the primary stability after in vitro application were gained. After fusion of 10 sheep cervical spines in the levels C2/3 and C4/5 in each case with PMMA and with an Ecopore-cage, radiologic as well as computertomographic examinations were performed postoperatively and every 4 weeks during the following 2 and 4 months, respectively. Apart from establishing our animal model, we analysed the radiological changes and the degree of bony fusion of the operated segments during the course. In addition we performed measurements of the corresponding disc space heights (DSH) and intervertebral angles (IVA) for comparison among each other, during the course and with the initial values. Immediately after placement of both implants in the disc spaces the mean DSH and IVA increased (34.8% and 53.9%, respectively). During the following months DSH decreased to a greater extent in the Ecopore-segments than in the PMMA-segments, even to a value below the initial value (p>0.05). Similarly, the IVA decreased in both groups in the postoperative time lapse, but more distinct in the Ecopore-segments (p<0.05). These changes in terms of a subsidence of the implants, were confirmed morphologically in the radiological examination in the course. The radiologically evaluated fusion, i.e. bony bridging of the operated segments, was more pronounced after implantation of an Ecopore-cage (83%), than after PMMA interposition (50%), but did not gain statistical significance. In this first in vivo examination of our new porous ceramic bone replacement material we showed its application in the spondylodesis model of the sheep cervical spine. Distinct radiological changes regarding evident subsidence and detectable fusion of the segments, operated on with the new biomaterial, were seen. We demonstrated the radiological changes of the fused segments during several months and analysed them morphologically, before the biomechanical evaluation will be presented in a subsequent publication. PMID:15655929

Korinth, M C; Hero, T; Mahnken, A H; Ragoss, C; Scherer, K

2004-12-01

251

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

252

Laser satellite power systems  

SciTech Connect

A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

Walbridge, E.W.

1980-01-01

253

Mission Benefits of Gridded Ion and Hall Thruster Hybrid Propulsion Systems  

NASA Technical Reports Server (NTRS)

The NASA In-Space Propulsion Technology (ISPT) Project Office has been developing the NEXT gridded ion thruster system and is planning to procure a low power Hall system. The new ion propulsion systems will join NSTAR as NASA's primary electric propulsion system options. Studies have been performed to show mission benefits of each of the stand alone systems. A hybrid ion propulsion system (IPS) can have the advantage of reduced cost, decreased flight time and greater science payload delivery over comparable homogeneous systems. This paper explores possible advantages of combining various thruster options for a single mission.

Dankanich, John W.; Polsgrove, Tara

2006-01-01

254

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

255

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

256

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

257

Prospects of thermionic power systems  

NASA Technical Reports Server (NTRS)

Potential thermionic power systems for space or terrestrial applications are described so that the development goals can be clearly identified. The thermionic power systems considered are a space nuclear power system, a fossil-fuel thermionic topping steam power system, a solar thermionic topping steam power system, and advanced systems. Attention is given to a discussion of the current status of technology development in thermionic converters and associated elements in power systems. Future prospects of thermionic power systems are also discussed. It is concluded that thermionic conversion has a great potential for a variety of applications.

Shimada, K.

1978-01-01

258

Financial study of commercialization of solar central receiver power systems  

NASA Astrophysics Data System (ADS)

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

1981-03-01

259

ELECTRICAL POWER SYSTEM HEALTH MANAGEMENT  

Microsoft Academic Search

One of the most critical systems in any aerospace vehicle is the electrical power system. Comprised of energy generation, energy storage, power distribution, and power management, the electrical power system (EPS) is relied upon by every major subsystem for proper operation. In order to meet the safety requirements of aeronautics and space systems - and provide for their reliability, maintainability,

Robert M. Button; Amy Chicatelli

260

Power systems testing  

NASA Technical Reports Server (NTRS)

The Space Station Freedom (SSF) will give the U.S. a permanent manned presence in space in 1999. The SSF underwent its final design concept in 1991. Launches of hardware will begin in late 1995, and the SSF will become operational in the man tended configuration in 1997. Additional Space Shuttle flights between 1997 and 1999 will complete the SSF. Along with international partners, a crew of four astronauts will conduct long-term experimentation in the microgravity environment of the orbiting spacecraft. Lewis Research Center, along with its prime contractor, will provide the electrical power system (EPS) for SSF. Two major testing facilities at the Lewis Research Center will support the Lewis EPS. The Power Systems Facility provides test beds for life testing the station batteries and the power management distribution system testbed. This testbed simulates two channels of the EPS. The Space Power Facility at the Lewis Plum Brook Station is the largest vacuum chamber in the world. Within this chamber, a simulated space environment, testing of full-size EPS components will occur.

1991-01-01

261

Dynamic power management in environmentally powered systems  

Microsoft Academic Search

In this paper a framework for energy management in energy harvesting embedded systems is presented. As a possible example scenario, we focus on wireless sensor nodes which are powered by solar cells. We demonstrate that classical power management solutions have to be reconceived and\\/or new problems arise if perpetual operation of the system is required. In particular, we provide a

Clemens Moser; Jian-Jia Chen; Lothar Thiele

2010-01-01

262

Advanced Solar Power Systems  

NASA Technical Reports Server (NTRS)

The Advanced Solar Power System (ASPS) concentrator uses a technically sophisticated design and extensive tooling to produce very efficient (80 to 90%) and versatile energy supply equipment which is inexpensive to manufacture and requires little maintenance. The advanced optical design has two 10th order, generalized aspheric surfaces in a Cassegrainian configuration which gives outstanding performance and is relatively insensitive to temperature changes and wind loading. Manufacturing tolerances also have been achieved. The key to the ASPS is the direct absorption of concentrated sunlight in the working fluid by radiative transfers in a black body cavity. The basic ASPS design concepts, efficiency, optical system, and tracking and focusing controls are described.

Atkinson, J. H.; Hobgood, J. M.

1984-01-01

263

Lunar power systems  

NASA Astrophysics Data System (ADS)

The findings of a study on the feasibility of several methods of providing electrical power for a permanently manned lunar base are provided. Two fundamentally different methods for lunar electrical power generation are considered. One is the use of a small nuclear reactor and the other is the conversion of solar energy to electricity. The baseline goal was to initially provide 300 kW of power with growth capability to one megawatt and eventually to 10 megawatts. A detailed, day by day scenario for the establishment, build-up, and operational activity of the lunar base is presented. Also presented is a conceptual approach to a supporting transportation system which identifies the number, type, and deployment of transportation vehicles required to support the base. An approach to the use of solar cells in the lunar environment was developed. There are a number of heat engines which are applicable to solar/electric conversions, and these are examined. Several approaches to energy storage which were used by the electric power utilities were examined and those which could be used at a lunar base were identified.

1986-12-01

264

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

265

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

National Technical Information Service (NTIS)

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

1983-01-01

266

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

267

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

268

Power and process control systems  

Microsoft Academic Search

This book contains the following chapters: Introduction to process control: Instrumentation, Identification, and Control; Standard-Form PID Controller Tuning; Dynamic Energy and Optimization; Drum Level Control in High-Pressure Steam Boilers; Cogeneration Power Plant Dynamics and Control; Power System Control and Operation; Power-Frequency Control in Electrical Energy Systems; Power Plant Dynamic Control; and Stability and Synchronization.

Polonyi

1991-01-01

269

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

270

Standardized power system controller architecture  

Microsoft Academic Search

This paper presents a concept for a standardized power system controller (PSC) architecture which is based on a powerful PSC, power converter devices, distributed I\\/O devices, simplified measuring principles, local\\/remote user interfaces and a highly flexible SW architecture. The devices can be used to build small as well big telecom power systems which all have the same set of sophisticated

Roland Scherwey

2007-01-01

271

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

272

Power plant feedwater system  

SciTech Connect

A feedwater heater system for a steam turbine power plant is provided which incorporates a liquid-to-liquid heat exchanger in addition to a plurality of vapor-to-liquid feedwater heaters. The advantage of this configuration is that the potential magnitude of entrained impurities within the feedwater stream is reduced without a significant increase in the overall heat rate of the steam turbine power plant. A preferred embodiment of the present invention incorporates three low pressure feedwater heaters and two high pressure feedwater heaters in conjunction with a drain cooler which is connected serially between the low and high pressure feedwater heaters. An alternative embodiment of the present invention incorporates a liquid-to-liquid heat exchanger connected hydraulically in parallel with the low pressure feedwater heaters. In both embodiments of the present invention, the liquid-to-liquid heat exchanger of the present invention receives the drain water from a reheater, such as a moisture separator-reheater, and exhausts this liquid to a condenser of the steam turbine power plant.

Silvestri, G.

1985-12-31

273

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

274

Control of Distributed Power Systems  

Microsoft Academic Search

A large number of distributed generation (DG) units are being integrated into power systems at distribution level. The DG units play an essential role in affecting the efficiency and performance of power systems. This paper describes some possible controlling modes of DG units. The operation and control of the power systems consisting of DG units, in particular separated subsystems, are

Z. Chen; Y Hu; F. Blaabjerg

2006-01-01

275

Power electronics transforms aircraft systems  

Microsoft Academic Search

This paper describes the secondary power sources available on a large transport aircraft and discusses expectation that power electronics will enable the transforming of present aircraft systems into new highly integrated systems. The benefits expected from integrating all of the engine-based hydraulic and pneumatic power sources into a single electrical system are identified in qualitative terms. The estimated capacity of

L. J. Feiner

1994-01-01

276

Thermoelectric module construction for low temperature gradient power generation  

Microsoft Academic Search

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

Y. Meydbray; R. Singh; Ali Shakouri

2005-01-01

277

POWER SYSTEMS DEVELOPMENT FACILITY  

SciTech Connect

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

Unknown

2002-11-01

278

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

279

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

280

Automated Power Systems Management (APSM)  

NASA Technical Reports Server (NTRS)

A breadboard power system incorporating autonomous functions of monitoring, fault detection and recovery, command and control was developed, tested and evaluated to demonstrate technology feasibility. Autonomous functions including switching of redundant power processing elements, individual load fault removal, and battery charge/discharge control were implemented by means of a distributed microcomputer system within the power subsystem. Three local microcomputers provide the monitoring, control and command function interfaces between the central power subsystem microcomputer and the power sources, power processing and power distribution elements. The central microcomputer is the interface between the local microcomputers and the spacecraft central computer or ground test equipment.

Bridgeforth, A. O.

1981-01-01

281

Batteries and Power Systems  

NSDL National Science Digital Library

All About Circuits is a website that âÂÂprovides 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 âÂÂDirect 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.

2008-07-14

282

Satellite Power System (SPS)  

NASA Technical Reports Server (NTRS)

Potential organizational options for a solar power satellite system (SPS) were investigated. Selection and evaluation criteria were determined to include timeliness, reliability, and adequacy to contribute meaningfully to the U.S. supply; political feasibility (both national and international); and cost effectiveness (including environmental and other external costs). Based on these criteria, four organizational alternatives appeared to offer reasonable promise as potential options for SPS. A large number of key issues emerged as being factors which would influence the final selection process. Among these issues were a variety having to do with international law, international institutions, environmental controls, economics, operational flexibility, congressional policies, commercial-vs-governmental ownership, national dedication, and national and operational stategic issues.

Edler, H. G.

1978-01-01

283

Introduction to Spectroscopy PowerPoint Presentation  

NSDL National Science Digital Library

This is a downloadable PowerPoint presentation about spectroscopy. Learners read and/or hear about the science of spectroscopy, what a spectrum is, and how spectroscopy is important to astronomy. This PowerPoint accompanies the Stanford Solar Center's Build Your Own Spectroscope activity, but it can be used as a stand-alone presentation for learners.

284

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

285

Power Quality Monitoring of Power System Based on Spectrum Analysis  

Microsoft Academic Search

Monitor and analysis of power system is very important to guarantee power quality. Accidents often occur because of bad power supply quality. So power department and user of electric power all want to improve power quality. Monitor and analysis System of power quality is widely used. The paper monitored fluctuated condition of power quality index by means of method of

Li Penghui; Zhao Lijie; Bai Haijun; Zhang Yanhua

2010-01-01

286

The space station power system  

NASA Technical Reports Server (NTRS)

The major requirements and guidelines that affect the NASA Space 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 preliminary design phase is described. Early station concepts, both fanciful and feasible, are described and linked to the present concept. The Phase B trade study selections of photovoltaic system technologies are detailed. Solar dynamic and power management and distribution systems are summarized.

Baraona, Cosmo R.

1986-01-01

287

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

SciTech Connect

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

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

1982-02-01

288

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

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

289

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

290

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  

Microsoft Academic Search

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

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

2010-01-01

291

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

292

Performance evaluation of adding ethanol production into an existing combined heat and power plant.  

PubMed

In this paper, the configuration and performance of a polygeneration system are studied by modelling the integration of a lignocellulosic wood-to-ethanol process with an existing combined heat and power (CHP) plant. Data from actual plants are applied to validate the simulation models. The integrated polygeneration system reaches a total efficiency of 50%, meeting the heating load in the district heating system. Excess heat from the ethanol production plant supplies 7.9 MW to the district heating system, accounting for 17.5% of the heat supply at full heating load. The simulation results show that the production of ethanol from woody biomass is more efficient when integrated with a CHP plant compared to a stand-alone production plant. The total biomass consumption is reduced by 13.9% while producing the same amounts of heat, electricity and ethanol fuel as in the stand-alone configurations. The results showed that another feature of the integrated polygeneration system is the longer annual operating period compared to existing cogeneration. Thus, the renewable electricity production is increased by 2.7% per year. PMID:19758800

Starfelt, F; Thorin, E; Dotzauer, E; Yan, J

2010-01-01

293

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

294

POWER SYSTEMS DEVELOPMENT FACILITY  

SciTech Connect

This report discusses test campaign GCT3 of the Halliburton KBR transport reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The transport reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using one of two possible particulate control devices (PCDs). The transport reactor was operated as a pressurized gasifier during GCT3. GCT3 was planned as a 250-hour test run to commission the loop seal and continue the characterization of the limits of operational parameter variations using a blend of several Powder River Basin coals and Bucyrus limestone from Ohio. The primary test objectives were: (1) Loop Seal Commissioning--Evaluate the operational stability of the loop seal with sand and limestone as a bed material at different solids circulation rates and establish a maximum solids circulation rate through the loop seal with the inert bed. (2) Loop Seal Operations--Evaluate the loop seal operational stability during coal feed operations and establish maximum solids circulation rate. Secondary objectives included the continuation of reactor characterization, including: (1) Operational Stability--Characterize the reactor loop and PCD operations with short-term tests by varying coal feed, air/coal ratio, riser velocity, solids circulation rate, system pressure, and air distribution. (2) Reactor Operations--Study the devolatilization and tar cracking effects from transient conditions during transition from start-up burner to coal. Evaluate the effect of process operations on heat release, heat transfer, and accelerated fuel particle heat-up rates. Study the effect of changes in reactor conditions on transient temperature profiles, pressure balance, and product gas composition. (3) Effects of Reactor Conditions on Syngas Composition--Evaluate the effect of air distribution, steam/coal ratio, solids circulation rate, and reactor temperature on CO/CO{sub 2} ratio, H{sub 2}/converted carbon ratio, gasification rates, carbon conversion, and cold and hot gas efficiencies. Test run GCT3 was started on December 1, 2000, with the startup of the thermal oxidizer fan, and was completed on February 1, 2001. This test was conducted in two parts; the loop seal was commissioned during the first part of this test run from December 1 through 15, which consisted of hot inert solids circulation testing. These initial tests provided preliminary data necessary to understand different parameters associated with the operation and performance of the loop seal. The loop seal was tested with coal feed during the second part of the test run and additional data was gathered to analyze reactor operations and to identify necessary modifications to improve equipment and process performance. In the second part of GCT3, the gasification portion of the test, from January 20 to February 1, 2001, the mixing zone and riser temperatures were varied between 1,675 and 1,825 F at pressures ranging from 200 to 240 psig. There were 306 hours of solid circulation and 184 hours of coal feed attained in GCT3.

Unknown

2002-05-01

295

Performance evaluation of an experimental 100kW Kalyanpur solar photovoltaic power plant -- a case study  

SciTech Connect

The operational structures, functions and performance of a 100 kW (peak) grid interactive experimental solar photovoltaic power plant are being reported. The interconnection schemes of the modules forming arrays supplying power to the load are discussed. The fourth unit of the plant which is isolated and independently supplies power to the power grid has been studied. Several improvements in the performance has been suggested particularly in load management, power controller, voltage regulator and tracking for optimum utilization of the plant. It is found that the system utility can be highly improved by making the plant totally grid-interactive instead of using it as partially stand alone system. By load management multi role of the plant is suggested. In addition to its normal function the plant can work as storage and peak power plant.

Ashraf, I.; Iqbal, A.; Asghar, M.S.J. [Aligarh Muslin Univ. (India). Dept. of Electrical Engineering

1995-12-31

296

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

297

Enhancing small signal power system stability by coordinating unified power flow controller with power system stabilizer  

Microsoft Academic Search

Advancement of power electronic technologies makes ac systems to be more adaptive and flexible as new forms of power controller emerges in recent years. Though not yet well developed, underpinned research suggests that unified power flow controller (UPFC) is a promising power system controller. This paper proposes a method to coordinate UPFC with power system stabilizer (PSS) so as to

Wanliang Fang; H. W. Ngan

2003-01-01

298

Photovoltaic power system reliability considerations  

NASA Technical Reports Server (NTRS)

An example of how modern engineering and safety techniques can be used to assure the reliable and safe operation of photovoltaic power systems is presented. This particular application is for a solar cell power system demonstration project designed to provide electric power requirements for remote villages. The techniques utilized involve a definition of the power system natural and operating environment, use of design criteria and analysis techniques, an awareness of potential problems via the inherent reliability and FMEA methods, and use of fail-safe and planned spare parts engineering philosophy.

Lalli, V. R.

1980-01-01

299

Nuclear Power Plant Annunciator Systems.  

National Technical Information Service (NTIS)

Analyses of nuclear power plant annunciator systems have uncovered a variety of problems. Many of these problems stem from the fact that the underlying philosophy of annunciator systems have never been elucidated so as to impact the initial annunciator sy...

W. L. Rankin

1983-01-01

300

Power quality load management for large spacecraft electrical power systems  

NASA Technical Reports Server (NTRS)

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

Lollar, Louis F.

1988-01-01

301

Maintenance of photovoltaic power systems  

SciTech Connect

This publication establishes standard practices for inspection, testing, and maintenance of photovoltaic power systems at Department of the Navy installations. The practices and procedures are recommended to ensure reliable operation of the power systems. The manual covers photovoltaic-array, battery, voltage-regulator, inverter, and wiring subsystems. In addition, this manual provides a troubleshooting guide and self-study questions and answers.

Hall, M.R.

1984-08-01

302

Wind Power Systems 1. Overview  

E-print Network

Wind Power Systems 1. Overview 2. Simulation model for wind farm operation 3. Research topics systems 1.4 Wind power integration 1.5 Summary 2. Simulation model of wind farm operations 3. Research energy · Geothermal energy · Solar energy · Wind energy · Biomass · The energy sources can be renewable

Ding, Yu

303

Thermionic space power system concept  

NASA Technical Reports Server (NTRS)

A 100 kWe thermionic nuclear power system conceptual design has been completed as part of the SP-100 space power program. The configuration and performance of the baseline system and its components are described along with the rationale for the selection of coolant and structural material. Growth and scalability are also discussed.

Snyder, Harold J.; Masson, James H.

1987-01-01

304

Controlled Separation of Power Systems  

Microsoft Academic Search

Transmission lines are subject to internal and external faults. The internal faults are rapidly cleared leaving the power system in an un-faulted condition. However, they cause an imbalance between the generators' mechanical input and electrical output producing external faults that in turn separate the power system into imbalanced load and generation islands and consequently result in blackouts.

M. M. Adibi

2007-01-01

305

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

306

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

307

Power system state estimation for a spacecraft power system  

NASA Technical Reports Server (NTRS)

An application of the maximum likelihood state estimator to a space-based power system is presented. The state estimator uses current and voltage measurements to generate estimates of node voltages for an electrical power distribution system for the Space Shuttle. Preliminary results on the effect of noisy measurements on estimated parameters are reported. The software used in generating these results is part of an overall package being developed at Louisiana Tech University. Intended applications of this package include the analysis of power systems and real-time parallel processing on the Space Shuttle.

Berry, F. C.; Benitez, N. L.; Cox, M. D.

1990-01-01

308

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

309

Power generating system  

Microsoft Academic Search

A method and apparatus for generating energy are presented wherein fluid flowing from the base of a standpipe drives a power converter such as a turbine. The discharged fluid is recycled to the top of the standpipe by pumping chambers which are filled by the flowing fluid and then discharged by compressed air. The compressed air is derived from a

Gillilan

1978-01-01

310

Security for space power systems  

Microsoft Academic Search

An initial system security monitor (SSM) developed for the power system of a proposed US National Aeronautics and Space Administration (NASA) permanently manned space station is presented. Four types of ranked disturbances or faults to the transmission system are successively corrected by remedial action of the SSM. After each corrective action, the SSM verifies that the system change has been

G. L. Kusic; W. H. Allen; E. W. Gholdston; R. F. Beach

1990-01-01

311

Security for space power systems  

Microsoft Academic Search

An initial system security monitor (SSM) developed for the power system of a proposed NASA permanently manned space station is presented. Four types of ranked disturbances or faults to the transmission system are successively corrected by remedial action of the SSM. After each corrective action, the SSM verifies the system change that has been implemented, then proceeds to examine lower-priority

G. L. Kusic; W. H. Allen; E. W. Gholdston; R. F. Beach

1990-01-01

312

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

313

A novel telecom power system  

Microsoft Academic Search

Typically, telecom power systems are connected to grid and diesel generator. This paper represents a new telecom power system using local micro-sources (fuel cell and micro-turbine). Some benefits of this system are effectively eliminating batteries, diesel generator and automatic transfer switch. In this paper, a new multiple input buck-boost converter is utilized as an interface between the micro-sources and the

O. Shirazi; O. Onar; A. Khaligh

2008-01-01

314

Information System Security Critical Elements Please note that prior to including this language in the performance plans of employees covered by  

E-print Network

Information System Security Critical Elements Please note that prior to including this language fulfilled. Stand-Alone Critical Elements Senior Agency Information Security Officer/Chief Information Security Officer/ Information Technology Security Officer Critical Element and Objective · Senior Agency

315

Balloon Fuel Cell Power System  

NASA Technical Reports Server (NTRS)

NASA Lewis Research Center's Electrochemical Technology Branch has teamed with the NASA Wallops Flight Facility to demonstrate the operation of a hydrogen-oxygen proton exchange membrane (PEM) fuel cell for application in the upper atmosphere. NASA Wallops' Balloon Programs Branch has a requirement for a high-power, long-duration power system for use on a scientific balloon platform. The current power system will not meet these needs. The objective of this program is to deliver a 200-W (minimum) fuel cell system that can deliver approximately 10 kWh of electrical energy.

1997-01-01

316

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

317

Power systems for future missions  

NASA Astrophysics Data System (ADS)

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.

1994-12-01

318

Electric-Power System Simulator  

NASA Technical Reports Server (NTRS)

Shows different combinations of generation, storage, and load components: display, video monitor with keyboard input to microprocessor, and video monitor for display of load curves and power generation. Planning tool for electric utilities, regulatory agencies, and laymen in understanding basics of electric-power systems operation.

Caldwell, R. W.; Grumm, R. L.; Biedebach, B. L.

1984-01-01

319

Power System Balancing Using FRIENDS  

Microsoft Academic Search

This paper proposes a new concept named Flexible, Reliable and Intelligent ENergy Delivery System (FRIENDS) as a future power distribution system. In FRIENDS, new facilities called Quality Control Centers (QCCs), which consists of Voltage Control type Inverters, Distributed Generators (DGs), Energy Storage Systems (ESSs), etc., are installed between distribution substation and customers. By controlling and operating those inverters and DGs

K. Keerthivasan; L. Krishnaveni; Jovitha Jerome

2011-01-01

320

Distributed vs. Centralized Power Systems Frequency Control  

E-print Network

Distributed vs. Centralized Power Systems Frequency Control Martin Andreasson12 , Dimos V control of electrical power systems. We propose a distributed controller which retains the reference class of large- scale systems are electrical power systems, which employ automatic generation control

Dimarogonas, Dimos

321

Power Systems Advanced Research  

SciTech Connect

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

California Institute of Technology

2007-03-31

322

Solar powered desalination system  

E-print Network

2.3: Pro-Lab® Water Quality Test Test pH Total Alkalinitycompare. Table 2.5: Water Quality Test Results Test pH TotalWater Quality Test Result Strips Generally, each solution before going through the reverse osmosis system had low pH and

Mateo, Tiffany Alisa

2011-01-01

323

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

324

Power system interface and umbilical system study  

NASA Technical Reports Server (NTRS)

System requirements and basic design criteria were defined for berthing or docking a payload to the 25 kW power module which will provide electrical power and attitude control, cooling, data transfer, and communication services to free-flying and Orbiter sortie payloads. The selected umbilical system concept consists of four assemblies and command and display equipment to be installed at the Orbiter payload specialist station: (1) a movable platen assembly which is attached to the power system with EVA operable devices; (2) a slave platen assembly which is attached to the payload with EVA operable devices; (3) a fixed secondary platen permanently installed in the power system; and (4) a fixed secondary platen permanently installed on the payload. Operating modes and sequences are described.

1980-01-01

325

Analysis methods for wind turbine control and electrical system dynamics  

NASA Technical Reports Server (NTRS)

The integration of new energy technologies into electric power systems requires methods which recognize the full range of dynamic events in both the new generating unit and the power system. Since new energy technologies are initially perceived as small contributors to large systems, little attention is generally paid to system integration, i.e. dynamic events in the power system are ignored. As a result, most new energy sources are only capable of base-load operation, i.e. they have no load following or cycling capability. Wind turbines are no exception. Greater awareness of this implicit (and often unnecessary) limitation is needed. Analysis methods are recommended which include very low penetration (infinite bus) as well as very high penetration (stand-alone) scenarios.

Hinrichsen, E. N.

1995-01-01

326

Space Station power system issues  

NASA Technical Reports Server (NTRS)

Issues governing the selection of power systems for long-term manned Space Stations intended solely for earth orbital missions are covered briefly, drawing on trade study results from both in-house and contracted studies that have been conducted over nearly two decades. An involvement, from the Program Development Office at MSFC, with current Space Station concepts began in late 1982 with the NASA-wide Systems Definition Working Group and continued throughout 1984 in support of various planning activities. The premise for this discussion is that, within the confines of the current Space Station concept, there is good reason to consider photovoltaic power systems to be a venerable technology option for both the initial 75 kW and 300 kW (or much greater) growth stations. The issue of large physical size required by photovoltaic power systems is presented considering mass, atmospheric drag, launch packaging and power transmission voltage as being possible practicality limitations. The validity of searching for a cross-over point necessitating the introduction of solar thermal or nuclear power system options as enabling technologies is considered with reference to programs ranging from the 4.8 kW Skylab to the 9.5 gW Space Power Satellite.

Giudici, R. J.

1985-01-01

327

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

328

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

329

Solar-powered cooling system  

DOEpatents

A solar-powered adsorption-desorption refrigeration and air conditioning system uses nanostructural materials made of high specific surface area adsorption aerogel as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material. A circulation system circulates refrigerant from the nanostructural material to a cooling unit.

Farmer, Joseph C

2013-12-24

330

Molecular mechanics and dynamics characterization of an in silico mutated protein: a stand-alone lab module or support activity for in vivo and in vitro analyses of targeted proteins.  

PubMed

Over the past 20 years, the biological sciences have increasingly incorporated chemistry, physics, computer science, and mathematics to aid in the development and use of mathematical models. Such combined approaches have been used to address problems from protein structure-function relationships to the workings of complex biological systems. Computer simulations of molecular events can now be accomplished quickly and with standard computer technology. Also, simulation software is freely available for most computing platforms, and online support for the novice user is ample. We have therefore created a molecular dynamics laboratory module to enhance undergraduate student understanding of molecular events underlying organismal phenotype. This module builds on a previously described project in which students use site-directed mutagenesis to investigate functions of conserved sequence features in members of a eukaryotic protein kinase family. In this report, we detail the laboratory activities of a MD module that provide a complement to phenotypic outcomes by providing a hypothesis-driven and quantifiable measure of predicted structural changes caused by targeted mutations. We also present examples of analyses students may perform. These laboratory activities can be integrated with genetics or biochemistry experiments as described, but could also be used independently in any course that would benefit from a quantitative approach to protein structure-function relationships. PMID:24259335

Chiang, Harry; Robinson, Lucy C; Brame, Cynthia J; Messina, Troy C

2013-01-01

331

was induced by a controlled titration (0.4 M NaOH, 0.4 M HCl) in a phosphate-based buffer system (0.05 M per liter, pH 8.6, 0.15 M ion  

E-print Network

) during the cul- tivation of animal and human cells. The first member of this product line is the SENSOLUX® stand-alone, an intelligent shaker tray with an integrated sensor system. Used in combination

Cai, Long

332

Controllability and diagnosis in electric power systems  

Microsoft Academic Search

While modern electric power systems are often operated under stressed conditions, there is an increasing social demand for reliable electricity supplies. The reliable operation of a power system depends on the power system's ability to maintain a normal operating condition following a disturbance. This study focuses on two aspects of power systems: Controllability and diagnosis, both concerned with the power

Mingguo Hong

1998-01-01

333

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

334

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

335

Power Take-Off Systems  

Microsoft Academic Search

In this chapter the main mechanisms that can be implemented to convert wave into mechanical and\\/or electrical energy are discussed.\\u000a Such mechanisms are often called power take-off (PTO) or power conversion systems (the first is adopted throughout the book).\\u000a The review is directly linked with the most commonly used options and to those which are linked with the technologies described

Richard Curran; Matthew Folley; Oskar Danielsson; Karin Thorburn; Mats Leijon; Jamie Taylor

336

Power system stability using fuzzy logic based Unified Power Flow Controller in SMIB power system  

Microsoft Academic Search

The paper presents a control method of damping low frequency power system oscillations using fuzzy logic based Unified Power Flow Controller (UPFC) installed in a single-machine infinite-bus (SMIB) power system. The objective of the Fuzzy Logic based UPFC controller is to damp power system oscillations. UPFC controller based upon amplitude modulation index of shunt converter (exciter) mE has been designed.

Rajan Manrai; Rintu Khanna; Balwinder Singh; Pooja Manrai

2012-01-01

337

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

338

Distributed generation with photovoltaic systems: A utility perspective  

SciTech Connect

Today PV power systems are already cost-effective and commonly employed in a wide range of remote applications such as electricity supply to isolated users and small communities; water pumping and desalination; powering of service equipment such as radio repeaters; pipelines and well-heads cathodic protection. PV systems can easily cover a broad range of power requirements, allowing them to take advantage of new niche markets as they develop. Besides such applications a ``non-power'', low performance, consumer market also exists (watches, calculators, gadgets) that has already reached a stable growth condition. In the last decade, an increase has been experienced of about three times in the amount of module shipments (103 MW expected in 1997), a more balanced regional manufacturer share has developed, crystalline technology has maintained its lead, and a more market-oriented application share has appeared (at present most applications are for stand-alone).

Vigotti, R.

1998-07-01

339

AC power electronic systems: Stability and power quality  

Microsoft Academic Search

This paper presents an overview of ac power electronic system modeling and analysis methods. Characteristics of such systems are first discussed, and their applications and significance in renewable energy and distributed generation (DG), transportation, and other mobile and autonomous power systems are highlighted. Typical stability and power quality problems encountered in these systems are demonstrated by measurements from several practical

Jian Sun

2008-01-01

340

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

341

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

342

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

343

TESTING THE STAND-ALONE MICROBEAM AT COLUMBIA UNIVERSITY  

E-print Network

quadrupole triplets. Using a `home made' 6.5 mCi polonium source, a 1 alpha particle s­1 , 10 lm diameter collimated microbeam beamline at RARAF. Simulations indicate that, using a 6.5 mCi 210 Po source, a beam flux

344

Developing a Stand Alone Sun Photometer for Ships and Buoys  

NASA Technical Reports Server (NTRS)

During November and December 1995 the first Aerosol Characterization Experiment (ACE 1) was carried to characterize the aerosol physical and optical properties in the clean marine atmosphere near Tasmania in the South Pacific. As part of this effort, and with funding from this proposal, we installed a sun photometer on the R/V Discoverer and a spectro-photometer on the NOAA C-130 aircraft.

Porter, John N.

1997-01-01

345

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

346

Homopolar generator power supply system  

SciTech Connect

A high-energy, high-current homopolar generator pulsed power supply system that is compact and field portable. The power supply system includes a homopolar generator (HPG), an auxiliary supply and drive system, both mounted on a skid frame, and a control system coupled to the HPG and drive system. The homopolar generator has a split rotor with insulation between the halves and a recess in the periphery. A stator ring and field coil, for producing a magnetic field through which the rotor halves make two simultaneous voltage-generating passes, are disposed within the recess in the rotor. Air-actuated brush mechanisms inside and outside the recess contact surfaces of the rotor and collect discharge current. The auxiliary supply and drive system includes a motoring system comprising hydraulic motors for driving the HPG to speed, a bearing lubrication system, a generator for energizing the field coil, and a brush actuator air supply system, all of which are driven by a prime mover. The control system comprises a logic controller for executing a prescribed sequence of steps including turning on the prime mover, initiating motoring of the HPG, energizing the field coil, and initiating the discharge of electrical current.

Weldon, W. F.; Gully, J. H.

1985-10-01

347

SOLERAS - Solar-Powered Water Desalination Project at Yanbu: PKI collectors performance  

Microsoft Academic Search

The seawater desalination pilot plant at Yanbu in Saudi Arabia is a unique experiment in which an indirect bulk freeze desalination process is integrated with a stand-alone solar cogeneration power plant. Thermal energy is stored in molten salt and is converted into shaft power required for primary refrigeration by a conventional steam engine. An absorption refrigeration unit is thermally driven

Hamad

1987-01-01

348

Analysis of Hybrid Power Systems  

Microsoft Academic Search

The paper contains the modelling of system comprising, the diesel generator, wind energy source, photovoltaic cell, solar power cells in source side domestic load, Industrial load in load side. The diesel generator is considered as a controlled energy source, and the wind is an uncontrolled energy source and the domestic load as an uncontrolled energy sink. All the components are

Vivek Venkoba Rao; Chellamuthu Chinnagounder

2007-01-01

349

Visualization for shipboard power systems  

Microsoft Academic Search

Shipboard power systems (SPS) are geographically spread all along the ship. It consists of various components such as generators, cables, switchboards, circuit-breakers, bus transfer switches and loads all interconnected with each other and located at various places (decks) on the ship. Geographical information on these components is required to assess the impact of faults caused due to battle damage or

K. L. Butler-Purry; N. D. R. Sarma

2003-01-01

350

Visualization for Shipboard Power Systems  

Microsoft Academic Search

Abstract Shipboard Power Systems (SPS) are geographically spread all along the ship It consists of various components such as generators, cables, switchboards, circuit - breakers, bus transfer switches and loads, all interconnected with each other and located at various places (decks) on the ship Geographical information on these components is required to assess the impact of faults caused due to

Karen L. Butler; Purry N. D. R. Sarma

2003-01-01

351

Condensation system for power plant  

Microsoft Academic Search

A condensation system for use in a power plant including a steam generator and steam turbine comprises at least one side stream condenser. The side stream condenser defines therein first and second hot wells with the first hot well receiving therein condensate produced by condensing steam exhausted from the steam turbine. A condensate pump device forcibly delivers the condensate through

H. Ishimaru; T. Masuda; Y. Nagai

1984-01-01

352

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

353

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

354

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

355

Introduction to Electric Power Systems  

NSDL National Science Digital Library

This fine course is offered as a welcome addition to MIT's OpenCourseWare initiative. The materials from this version of "Introduction to Electric Power Systems" are from the iteration taught by Professor James Kirtley in Spring 2011. On the site, visitors can look over the syllabus, the course calendar, readings, assignments, and quizzes. The topics covered here include load flow, power electric motor drives, and polyphase networks. The site also includes a number of problem sets, along with their accompanying solutions. Visitors can look over the readings and provide feedback on the course to the site administrators.

Kirtley, James L.

2011-01-01

356

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

357

Power flow calculation for power system including offshore wind farm  

Microsoft Academic Search

This paper proposes a simplified steady-state equivalent model of asynchronous generators. With regard to the relationship between the wind velocity and generator's active power, terminal voltage, reactive power, as well as the slip ratio, a method to calculate the power flow for power system including large-scale offshore wind farm is then proposed, using the DLL files called by UPI of

Zhang Wei; Wei Zhinong; Sun Guoqiang

2009-01-01

358

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

359

124 Home Power #83 June / July 2001 Code Corner  

E-print Network

run five separate source circuits from the PV array to the inverter (one for each of the five strings the proper array conductors for a PV system. This 2,000 watt, 48 volt PV array will be mounted on the roof and elsewhere these days. But the PV array wiring would be similar in a stand-alone system. Specifications

Johnson, Eric E.

360

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

361

Integrated operation system for telecommunications power equipment  

Microsoft Academic Search

Nippon Telegraph and Telephone Corporation (NTT) has developed ALICE (Advanced power Plants Integrated maintenance Control systEm), an intelligent system for operating telecommunications power equipment. This system performs not only centralized supervision and control functions, but also information processing (relational database and data communications tasks) and diagnostic functions. It accomplishes diagnoses by applying expert system technology to power equipment. The system

H. Yamamura; I. Kase; H. Ikebe

1990-01-01

362

Intelligent wind power prediction systems final report  

E-print Network

Intelligent wind power prediction systems ­ final report ­ Henrik Aalborg Nielsen (han (FU 4101) Ens. journal number: 79029-0001 Project title: Intelligent wind power prediction systems #12;#12;Intelligent wind power prediction systems 1/36 Contents 1 Introduction 6 2 The Wind Power Prediction Tool 7 3

363

On Power System Controlled Separation  

Microsoft Academic Search

This paper describes verification of five conjectures related to power system controlled separation. It attempts to verify that the location of uncontrolled separation (loss of synchronism or out-of-step operation) is independent of the location and severity (short-circuit duty or duration) of the initial faults, that the location depends on the prevailing network configuration and load level, and that it takes

M. M. Adibi; R. J. Kafka; Sandeep Maram; Lamine M. Mili

2006-01-01

364

Shipboard Power System Reconfiguration Using Multi Agent System  

Microsoft Academic Search

The reconfiguration process for Shipboard Power System reroutes the electric power in the power system in order to achieve certain objectives, such as maximizing service restoration, minimizing power loss, optimizing power dispatch, etc. The reconfiguration process can improve the survivability and reliability of the power system.\\u000aVarious methods have been applied to the reconfiguration process of power systems. But most

Kai Huang

2007-01-01

365

A high power density high voltage distributed power system for pulse power applications  

Microsoft Academic Search

In this paper, a high-density high-voltage distributed power system for pulse power applications is designed and implemented. Different topologies are evaluated for two power stages. According to pulse load condition, system power density is optimized through the tradeoff between power loss and magnetic component size. High power density and high efficiency are verified by the experimental result

Bing Lu; Yarig Qiu; Chuanyun Wang; Yonghan Kang; Juanjuan Sun; Wei Dong; Francisco Canales; Peter Barbosa; Ming Xu; Fred C. Lee; Richard Gean; Wesley C. Tipton; Damian Urciuoli

2005-01-01

366

Modeling Power Systems as Complex Adaptive Systems  

SciTech Connect

Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.

Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

2004-12-30

367

Study on photovoltaic power system on ships  

SciTech Connect

This paper presents the application of photovoltaic power systems to ships. Two types of leisure or fishing boats powered by photovoltaics are designed. The boats described are single hull and catamaran type with twin hulls. The design of a new electric power system using a photovoltaic power system in a harbor ship having 20 tons is also proposed. The results of this study show that the photovoltaic power system can apply to small ships.

Katagi, Takeshi; Fujii, Yoshimi; Nishikawa, Eiichi; Hashimoto, Takeshi [Kobe Univ. of Mercantile Marine (Japan)

1995-11-01

368

Power transaction issues in deregulated power systems  

E-print Network

Regulatory Commission (FERC) issued orders 888 and 889 to specify the role of available transmission capability (ATC). Consecutively, the North American Reliability Council (NERC) established a framework for ATC definition and evaluation [I] with which we... Calculation Method We illustrate here all the previous definitions in an example of ATC calculation using the network response method presented by NERC in [1]. Utilized Software To go through the exercises, we will use the Power Education Toolbox (PET...

Roycourt, Henrik

2012-06-07

369

Automatic calorimetry system monitors RF power  

NASA Technical Reports Server (NTRS)

Calorimetry system monitors the average power dissipated in a high power RF transmitter. Sensors measure the change in temperature and the flow rate of the coolant, while a multiplier computes the power dissipated in the RF load.

Harness, B. W.; Heiberger, E. C.

1969-01-01

370

Optimal Power Management in Wireless Control Systems  

E-print Network

Optimal Power Management in Wireless Control Systems Konstantinos Gatsis, Student Member, IEEE channels, power adaptation, linear quadratic control, con- trol/communication separation, event to the controller over a wireless fading channel. The power allocated to these transmissions determines

Plotkin, Joshua B.

371

Power Parks System Simulation Sandia National Laboratories  

E-print Network

the utility grid as a storage device, selling power to the utility when there is excess and drawing power when for power parks suggests that each system will be novel, at least in some aspect of its design. Consequently

372

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

373

Task 3.14 -- Demonstration of technologies for remote power generation in Alaska. Semi-annual report, July 1--December 31, 1995  

SciTech Connect

The overall goal of this project is a site specific demonstration of a small, environmentally acceptable electric generating system fueled on indigenous fuels and waste materials to serve the microgrid or stand alone power distribution systems typical of remote, isolated Alaska Native communities. The objective of the project is to develop a commercialization plan that includes an analysis of the quantity, quality, and cost of the available fuels; a mapping of the electricity and district heating needs of a selected community, including electrical distribution layout and interconnecting steam piping; a step by step review of the environmental regulations and permit applications that need to be met; and a preliminary design and budget for the demonstration of a 0.5 to 6 MWe power system to be completed by the Energy and Environmental Research Center (EERC) in a manner that provides technical and regulatory readiness to proceed with implementation of the demonstration.

NONE

1997-08-01

374

Electrical power generating system. [for windpowered generation  

NASA Technical Reports Server (NTRS)

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

Nola, F. J. (inventor)

1981-01-01

375

Application of Bifurcation Analysis to Power Systems  

Microsoft Academic Search

Electric power systems are physically some of the largest and most complex nonlinear systems in the world. Bifurcations are rather mundane phenomena in power systems. The pioneer work on the local bifurcation analysis of power systems can be dated back to the 1970s and earlier. Within the last 20 years or so nonlinear dynamical theory has become a subject of

Hsiao-Dong Chiang

376

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

377

Analysis of Power System Dynamics Subject to Stochastic Power Injections  

E-print Network

DAE model and the CTMC forms a stochastic process known as a Stochastic Hybrid System (SHS of renewable re- sources such as wind energy conversion systems (WECS) and photovoltaic energy conversion1 Analysis of Power System Dynamics Subject to Stochastic Power Injections Sairaj V. Dhople

DeVille, Lee

378

Small Solar Power Systems /SSPS/  

NASA Astrophysics Data System (ADS)

A detailed description is given of the project organization, hardware, and projected performance of the distributed collector and central receiver solar thermal research facilities comprising the Small Power Systems (SSPS) plants in Almeria, Spain. The Distributed Collector System (DCS) is rated at 500 kWe and employs two fields of line-focusing parabolic trough collectors. The Central Receiver System (CRS) has the same rating and uses liquid sodium as a heat-transfer medium to circulate the 530 C heat yielded by a concentration factor of 450 from 4000 sq m of reflective surface. The purpose of the plant's dual configuration is the comparison of the two concentration methods under identical environmental conditions and the responsibility of a single operator/evaluator.

Grasse, W.

1981-05-01

379

Uninterruptible power supply (UPS) systems  

SciTech Connect

Use of this purchase specification is not mandatory. User should review the document and determine if it meets the user`s purpose. This document contains a fill-in-the-blanks guide specification for the procurement of uninterruptible power supply (UPS) systems greater than 10 kVA, organized as follows: Parts 1 through 7--technical requirements; Appendix A--technical requirements to be included in the proposal; Appendix B--UPS system data sheets to be completed by each bidder (Seller) and submitted with the proposal; Appendix C--general guidelines giving the specifier parameters for selecting a UPS system; it should be read before preparing an actual specification, and is not attached to the specification; Attachment 1--sketches prepared by the purchaser (Owner); Attachment 2--sample title page.

NONE

1997-04-01

380

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

381

Small Power Technology Systems for Tetrahedral Rovers  

Microsoft Academic Search

The Small Power Technology (SPOT) being studied at GSFC has the potential to be an efficient and compact radioisotope based power system. Such a system would provide power for innovative tetrahedral robotic arms and walkers to support the lunar exploration initiative within the next decade. Presently, NASA has designated two flight qualified Radioisotope Power Supplies (RPS): the Multi-Mission RTG (MMRTG)

P. E. Clark; S. R. Floyd; C. D. Butler; Y. Flom

382

Large autonomous spacecraft electrical power system (LASEPS)  

NASA Technical Reports Server (NTRS)

NASA - Marshall Space Flight Center is creating a large high voltage electrical power system testbed called LASEPS. This testbed is being developed to simulate an end-to-end power system from power generation and source to loads. When the system is completed it will have several power configurations, which will include several battery configurations. These configurations are: two 120 V batteries, one or two 150 V batteries, and one 250 to 270 V battery. This breadboard encompasses varying levels of autonomy from remote power converters to conventional software control to expert system control of the power system elements. In this paper, the construction and provisions of this breadboard are discussed.

Dugal-Whitehead, Norma R.; Johnson, Yvette B.

1992-01-01

383

Costing the satellite power system  

NASA Technical Reports Server (NTRS)

The paper presents a methodology for satellite power system costing, places approximate limits on the accuracy possible in cost estimates made at this time, and outlines the use of probabilistic cost information in support of the decision-making process. Reasons for using probabilistic costing or risk analysis procedures instead of standard deterministic costing procedures are considered. Components of cost, costing estimating relationships, grass roots costing, and risk analysis are discussed. Risk analysis using a Monte Carlo simulation model is used to estimate future costs.

Hazelrigg, G. A., Jr.

1978-01-01

384

Power quality issues in a hybrid power system  

Microsoft Academic Search

We analyzed a power system network that consisted of two types of power generation: wind turbine generation and diesel generation. The power quality and the interaction of diesel generation, the wind turbine, and the local load were the subjects of investigation. From an energy-production standpoint, producing as much wind energy as possible is advantageous in terms of decreasing the fuel

Eduard Muljadi; H. Edward McKenna

2002-01-01

385

Operation experience of a solar- and wind-powered desalination demonstration plant  

Microsoft Academic Search

The present work outlines the designing, erection and operation process of a stand-alone desalination plant powered by both solar photovoltaic and wind energy. Such a plant will serve small isolated communities in remote areas devoid of water resources. A specially customized code was built to simulate the operation of the installation in order to allow appropriate choice of components specifications.

Dan Weiner; David Fisher; Eduard J. Moses; Baruch Katz; Giora Meron

2001-01-01

386

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

387

25 kW solar photovoltaic flat panel power supply for an electrodialysis water desalination unit in New Mexico. Final report, 1 October 1978-31 May 1979  

SciTech Connect

The stand-alone system designed by Mobil Tyco Solar Energy Corporation consists of a 25 kW flat panel array employing silicon ribbon solar cells, used in conjunction with a lead-acid battery bank to provide the complete power requirements of an electrodialysis water desalination unit. The Mobil Tyco system design is intended to be prototypical of part of the drinking water supply for a remote village. The specific task which this system will perform during Phase III is to aid in the restoration of an aquifer following a uranium leaching operation by the Energy Minerals Division of Mobil Oil Corporation at a site which is approximately four miles from the township of Crownpoint in northwestern New Mexico. System design is described, and a detailed description of a mathematical model and computerized simulation of the system is included. (WHK)

Wood, J.R.; Crutcher, J.L.

1980-06-01

388

ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

The purpose of this revision of the System Description Document (SDD) is to establish requirements that drive the design of the electrical power system and their bases to allow the design effort to proceed to License Application. This SDD is a living document that will be revised at strategic points as the design matures over time. This SDD identifies the requirements and describes the system design as they exist at this time, with emphasis on those attributes of the design provided to meet the requirements. This SDD has been developed to be an engineering tool for design control. Accordingly, the primary audience are design engineers. This type of SDD leads and follows the design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential to performing the design process. This SDD follows the design with regard to the description of the system. The description provided in the SDD is a reflection of the results of the design process to date. Functional and operational requirements applicable to this system are obtained from ''Project Functional and Operational Requirements'' (F&OR) (Siddoway, 2003). Other requirements to support the design process have been taken from higher level requirements documents such as ''Project Design Criteria Document'' (PDC) (Doraswamy 2004), the fire hazards analyses, and the preclosure safety analysis. The above mentioned low-level documents address ''Project Requirements Document'' (PRD) (Canori and Leitner 2003) requirements. This SDD includes several appendices with supporting information. Appendix B lists key system charts, diagrams, drawings, and lists; and Appendix C is a list of system procedures.

M. Maniyar

2004-06-22

389

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 Central

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

2012-01-01

390

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

391

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

392

Using SPICE for power system simulations  

Microsoft Academic Search

Power system simulation software is a useful tool for teaching the fundamentals of power system design and operation. However, existing commercial packages are not ideal for teaching work-based students because of high-cost, complexity of the software and licensing restrictions. This paper describes a set of power systems libraries that have been developed for use with the free, studentedition of a

Andrew Cross; Dani Strickland

2011-01-01

393

Options for Affordable Fission Surface Power Systems  

NASA Technical Reports Server (NTRS)

Fission surface power systems could provide abundant power anywhere on free surface of the moon or Mars. Locations could include permanently shaded regions on the moon and high latitudes on Mars. To be fully utilized; however, fission surface power systems must be safe, have adequate performance, and be affordable. This paper discusses options for the design and development of such systems.

Houts, Mike; Gaddis, Steve; Porter, Ron; VanDyke, Melissa; Martin Jim; Godfroy, Tom; Bragg-Sitton, Shannon; Garber, Anne; Pearson, Boise

2006-01-01

394

Evaluation of interconnected power systems controlled islanding  

Microsoft Academic Search

Controlled separation of power systems is the last defense line against wide-area blackout. As a special protection scheme, the methodology of system splitting is a comprehensive decision making problem. This paper introduces a novel approach for separation of the integrated power systems into several stable islands. The proposed method combines both the dynamic and static characteristics of interconnected power networks

S. Najafi

2009-01-01

395

Evaluation of Interconnected Power Systems Splitting  

Microsoft Academic Search

Controlled splitting of an interconnected power system is the last defense line against wide-area blackout. As a special protection scheme, the methodology of system splitting is a comprehensive decision-making problem. This article introduces a novel approach for separation of the integrated power systems into several stable islands. The proposed method combines both the dynamic and static characteristics of interconnected power

S. R. Najafi; S. H. Hosseinian; M. Abedi

2010-01-01

396

Security schemes of power systems against blackouts  

Microsoft Academic Search

A security scheme of the power systems should protect the integrity of the electric networks and carry out fast operations on the entire power system to prevent a possible blackout. Blackouts started as local failures led to electrical disturbances, and the complete collapse of the power systems. This work proposes a security scheme based in two stages. In the first

R. Moreno; M. A. Rios; A. Torres

2010-01-01

397

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

398

Integration of Storage Devices into Power Systems  

E-print Network

Report Power Systems Engineering Research Center Empowering Minds to Engineer the Future Electric Energy and Computer Engineering University of Illinois at Urbana-Champaign 1406 W. Green Street Urbana, IL 61801 Email: gross@illinois.edu Power Systems Engineering Research Center The Power Systems Engineering Research

399

Wind Power Systems 1.0 Overview  

E-print Network

Wind Power Systems 1.0 Overview 2.0 Simulation model for wind farm operation 3.0 Research topics #12;Contents 1. Overview of wind power systems 2. Simulation model of wind farm operations 3. Research area of wind power systems 3.0 Overview 3.1 Economic dispatch 3.2 Correlation analysis 3.3 Energy

Ding, Yu

400

An Open Source Power System Analysis Toolbox  

Microsoft Academic Search

This paper describes the Power System Analysis Toolbox (PSAT), an open source Matlab and GNU\\/Octave-based software package for analysis and design of small to medium size electric power systems. PSAT includes power flow, continuation power flow, optimal power flow, small-signal stability analysis, and time-domain simulation, as well as several static and dynamic models, including nonconventional loads, synchronous and asynchronous machines,

Federico Milano

2005-01-01

401

Preventing power outages Power system contingency analysis on the GPU  

E-print Network

Preventing power outages Power system contingency analysis on the GPU To provide electricity system will indeed stay functional is called contingency analysis. The GPU, i.e., the CPU of graphics run much faster on the GPU than on a single CPU, while the GPU is much cheaper than parallel machines

Vuik, Kees

402

Sizing Batteries for Photovoltaic Systems  

Microsoft Academic Search

This paper describes a computerprogram for sizing photovoltaic stand-alone systems (PV-systems) with batteries. The computer program is based on an insolation model described by M Collares-Pereira and Ari Rabl (1) and a newly developed battery algorithm. The algorithm is based on - capacity derating as a function of electrolyte temperature - charging efficiency as a function of electrolyte temperature and

Jan Johnsson

1987-01-01

403

Power system modeling and analysis of electric ship propulsion system  

Microsoft Academic Search

This paper deals with modeling and characteristic analysis of a large powered electric ship propulsion system. Particularly, electric power system modeling has been accomplished in accordance with the electric power network mainly composed of generators, switchboards, variable frequency devices, electric motors, and etc. In addition, electric power system analysis has been performed via load flow analysis. In particular, abnormal operating

Sanggon Lee; Sanghoon Kim; Yu-seok Jeong; Sang-Yong Jung

2009-01-01

404

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

405

Environmental Control and Life Support Systems and Power Systems ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Environmental Control and Life Support Systems and Power Systems - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

406

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

407

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

408

Power system damping enhancement via coordinated design of PSS & TCSC in multimachine power system  

Microsoft Academic Search

The main objective of this paper is to investigate the enhancement of power system stability via coordinated design of Thyristor Controlled Series Compensation (TCSC) and Power System Stabilizers (PSSs) in multimachine power system. The design problem of the proposed controllers is formulated as an optimization problem. Using the developed linearized power system model, the particle swarm optimization (PSO) algorithm is

M. B. Saleh; M. A. Abido

2006-01-01

409

An adaptive fuzzy logic based power system stabilizer for enhancement of power system stability  

Microsoft Academic Search

This paper presents the performance of fuzzy logic based adaptive power system stabilizer (PSS) for stability enhancement of Single Machine Infinite Bus power system. The PSS is used to generate supplementary control signals for the excitation system in order to damp the low frequency power system oscillations. Here speed deviation and accelerated power are the two inputs to the fuzzy

K. C. Rout; P. C. Panda

2010-01-01

410

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

411

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

412

Building a space solar power system  

Microsoft Academic Search

The solar power satellite (SPS) and space solar power system (SSPS) have been studied for years as future alternative energy sources when fossil fuel becomes scarce. The SPS is a satellite in orbit that collects solar energy and transmits the energy to various destinations. SSPS is a total system that includes SPS and ground facilities to utilize power from the

Mitsushige Oda

2005-01-01

413

Center for Power Electronics Systems PROGRESS REPORT  

E-print Network

Center for Power Electronics Systems PROGRESS REPORT FRED C. LEE DUSHAN BOROYEVICH 10 YEAR PARTNER-DIRECTOR #12;This space left blank #12;Center for Power Electronics Systems PARTNER UNIVERSITIES University: History of Power Electronics Describes how the goals and achievements of CPES build on thinking

Beex, A. A. "Louis"

414

An Intelligent Personalized Fashion Recommendation System  

Microsoft Academic Search

In this paper, we propose a novel system-Intelligent Personalized Fashion Recommendation System, which creates a new space in web multimedia mining and recommendation. The proposed system significantly helps customers find their most suitable fashion choices in mass fashion information in the virtual space based on multimedia mining. There are three stand-alone models developed in this paper to optimize the analysis

Qingqing Tu; Le Dong

2010-01-01

415

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

416

Status of space station power system  

NASA Technical Reports Server (NTRS)

The major requirements and guidelines that affect the manned space station configuration and the power systems 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 are described and linked to the present concept. The recently completed phase B tradeoff study selections of photovoltaic system technologies are described. The present solar dynamic and power management and distribution systems are also summarized for completeness.

Baraona, Cosmo R.; Sheibley, Dean W.

1987-01-01

417

Status of the Space Station power system  

NASA Technical Reports Server (NTRS)

The major requirements and guidelines that affect the manned Space Station configuration and the power systems 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 are described and linked to the present concept. The recently completed phase B tradeoff study selections of photovoltaic system technologies are described. The present solar dynamic and power management and distribution systems are also summarized for completeness.

Baraona, Cosmo R.; Sheibley, Dean W.

1988-01-01

418

Improved refractories for IGCC power systems  

SciTech Connect

Certain advantages make coal gasification a key element in the US Department of Energy's Vision 21 power system. However, issues of reliability and gasifier operation economics need to be resolved before gasification is widely adopted by the power generation industry.

Dogan, Cynthia P.; Kwong, Kyei-Sing; Bennet, James P.; Chinn, Richard E.; Dahlin, Cheryl L.

2002-09-01

419

Solid state remote power controllers for 120 Vdc power systems  

NASA Technical Reports Server (NTRS)

Solid state Remote Power Controllers (RPCs) developed for use in any dc power system with voltage up to 120 Vdc and distributed power up to 3.6 kW per bus are described. The RPCs were demonstrated to be reliable, 99 percent efficient, comparatively simple, and potentially low in cost. Advantages of the RPCs include: contactless switching; controlled rates of current rise and fall; current limiting; and fast, well-defined, repeatable response to overloads and faults.

Sundberg, G. R.; Baker, D. E.

1976-01-01

420

A distributed power generation communication system  

Microsoft Academic Search

A distributed power generation system (DPGS) consists of a number of small-scale power generation sources (SSPGS) that provide electric power at a site closer to the user than the central power generation station. Small-scale power generation technologies currently available include wind turbines, fuel cells, micro gas\\/diesel turbines, small hydro generators and photovoltaic panels. Currently, most SSPGSs are locally controlled and

Julian Meng

2003-01-01

421

Fuel cell system for powered balloon  

Microsoft Academic Search

A 4-month study was conducted to determine the most economical use of these power plants for a powered balloon system designated POBAL-S. The fuel cell power plant selected for this application is an existing model, the PC17A-3, tailored to deliver 2.5-kW at 30 V dc continuously for 7 days. In addition to the power plant itself, the system would contain

1973-01-01

422

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

423

Power Management and Distribution System Developed for Thermionic Power Converters  

NASA Technical Reports Server (NTRS)

A spacecraft solar, bimodal system combines propulsion and power generation into a single integrated system. An Integrated Solar Upper Stage (ISUS) provides orbital transfer capabilities, power generation for payloads, and onboard propulsion to the spacecraft. A key benefit of a bimodal system is a greater payload-to-spacecraft mass ratio resulting in lower launch vehicle requirements. Scaling down to smaller launch vehicles increases space access by reducing overall mission cost. NASA has joined efforts with the Air Force Phillips Laboratory to develop enabling technologies for such a system. The NASA/Air Force bimodal concept uses solar concentrators to focus energy into an integrated power plant. This power plant consists of a graphite core that stores thermal energy within a cavity. An array of thermionic converters encircles the graphite cavity and provides electrical energy conversion functions. During the power generation phase of the bimodal system, the thermionic converters are exposed to the heated cavity and convert the thermal energy to electricity. Near-term efforts of the ISUS bimodal program are focused on a ground demonstration of key technologies in order to proceed to a full space flight test. Thermionic power generation is one key technology of the bimodal concept. Thermionic power converters impose unique operating requirements upon a power management and distribution (PMAD) system design. Single thermionic converters supply large currents at very low voltages. Operating voltages can vary over a range of up to 3 to 1 as a function of operating temperature. Most spacecraft loads require regulated 28-volts direct-current (Vdc) power. A combination of series-connected converters and powerprocessing boosters is required to deliver power to the spacecraft's payloads at this level.

Baez, Anastacio N.

1998-01-01

424

Small nuclear power generation units, and electric power system interconnection  

Microsoft Academic Search

In this paper, we introduced a new paradigm for energy supply system in near future which produces electric and district heat cogeneration with dispersed power grid with small nuclear power generation units (SNPGU). Recently, in nuclear field, a lot of effort has been done in nuclear major countries to develop small and medium reactor for enhancement of nuclear peaceful use

Sang-Seung Lee; Jong-Keun Park; Seung-Il Moon; Yong-Tae Yoon; Jong-Won Kim; Goon-Cherl Park

2006-01-01

425

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

426

INFORMATION EMBEDDED POWER SYSTEM: THE EFFECTIVE COMMUNICATION SYSTEM OF THE 21ST CENTURY POWER SYSTEM INDUSTRY  

Microsoft Academic Search

Worldwide, electric utility deregulation is expanding and creating demands to integrate, consolidate and disseminate information quickly and accurately between and within utilities. The rapid development in information technology (IT) is pushing the power system information management network to a remarkable innovation state. This brings us new opportunities and challenges. Implementation of Information Embedded Power System via Wide Area Network (IEPS-W)

M. T. O. Amanullah; A. Kalam; A. Zayegh

2004-01-01

427

Survey of supervisory power system stabilizers for enhancement of power system stability  

Microsoft Academic Search

The weak performance of conventional power system stabilizers to damp inter-area oscillations during severe disturbances can cause the power systems to lose stability especially if the systems are highly oscillatory. To ensure small-signal stability of the systems, increasing interest has been focused on developing supervisory power system stabilizers (SPSS) as a means of remote feedback controllers to tackle the threat

H. Behbehani; Z. Lubosny; J. W. Bialek

2007-01-01

428

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

429

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

430

The Failure Analysis in Traction Power System  

NASA Astrophysics Data System (ADS)

This paper presents a failure analysis of traction power systems. The electric railway consists of traction power systems, various vehicles, operating equipment, track, overhead line and electric equipment. It is a fundamental function of traction power systems that they supply customers with acceptable reliability and high quality power. Perhaps the most commonly used reliability assessment for railway systems has been the failure analysis of the traction signal system. The reliability assessment of traction power systems has also been an indispensable issue for reliability assessment. This paper deals with the classification of railway accidents caused by electrification problems, the estimation of failure rate in power equipments and failure analysis using fault trees. In study cases, the fault tree method for failure analysis is applied to railway substations in South Korea.

Kim, Hyungchul; Heo, Guk-bum; Lee, Hyungwoo; Kim, Dong Jin; Kim, Jin O.

2008-10-01

431

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

432

Nuclear power plant steam system  

SciTech Connect

Apparatus utilizing steam from first, second and third extraction points of a steam turbine in a nuclear power plant steam system as heating steam in at least two feedwater heater units for maintaining the final feedwater temperature above a predetermined temperature value is disclosed. More specifically, when the plant loading is determined above a predetermined first level, the apparatus provides heating steam from the first extraction point to a final feedwater heater unit in the feedwater return path of the steam system and also provides heating steam, which is at a lower pressure than that from the first extraction point, from the second extraction point to another feedwater heater unit which preheats the feedwater prior to entering the final feedwater heater unit. At times, when the plant loading falls below the first level, heating steam, which is at a higher pressure than that of the first extraction point, is provided to the final feedwater unit from the third extraction point and a portion of the steam from the first extraction point is redirected as heating steam for the another feedwater heater unit. Moreover, at times, when the plant loading falls below a second predetermined level, which is lower than the first level, the heating steam from the third extraction point provided to the final feedwater heater unit is increased in pressure preferably by an ejector or jet pump device utilizing motive steam from a high pressure source, and in addition, a portion of the steam from the third extraction point is redirected to the another feedwater heater unit.

Silvestri, G.J.

1982-06-22

433

Hallam Nuclear Power Facility Electric Auxiliary-Power Systems  

Microsoft Academic Search

This paper describes the electric auxiliary-power systems in a sodium-cooled graphite-moderated nuclear reactor (SGR). Reliability requirements and methods of achieving them are discussed, and sodium-system preheating, a requirement unique to sodium-cooled reactors, is outlined. Nuclear instrumentation electric noise problems and methods of avoiding them are included. Auxiliary power requirements of a 360-mwe (electrical megawatt) SGR plant are compared with those

V. R. Pool

1963-01-01

434

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

435

Systematic tuning of nonlinear power system controllers  

Microsoft Academic Search

Nonsmooth nonlinearities have a significant influence within many power system controllers, and hence affect overall system dynamic behaviour. This paper focusses on the output limiters of power system stabilizers (PSSs). Even though these limits play an important role in the response of generators to large disturbances, only ad hoc tuning procedures have been available. Therefore a systematic, optimization-based approach is

Ian A. Hiskens

2002-01-01

436

Advanced Aircraft Secondary Power System Design  

Microsoft Academic Search

This paper describes the requirements, the secondary power system design, and the results of a trade study for an Advanced Aircraft Secondary Power System Design (AASPSD). AASPSD is an Air Force funded contract performed by The Boeing Company. The aircraft selected for this study was a Mach 6 vehicle. The three AASPSD configurations studied were a conventional system having hydraulic

E. J. Woods; C. S. Rubertus; I. S. Mehdi

1990-01-01

437

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

438

Dynamic power management for portable systems  

Microsoft Academic Search

Portable systems require long battery lifetime while still delivering high performance. Dynamic power management (DPM) policies trade off the performance for the power consumption at the system level in portable devices. In this work we present the time-indexed SMDP model (TISMDP) that we use to derive optimal policy for DPM in portable systems. TISMDP model is needed to handle the

Tajana Simunic; Luca Benini; Peter W. Glynn; Giovanni De Micheli

2000-01-01

439

Space-to-earth power transmission system  

NASA Technical Reports Server (NTRS)

A preliminary analysis was conducted to establish the requirements of a space-to-earth microwave power transmission system. The need for accurate phase control on the transmitter was established and methods for assessing the impact of power density and thermal constraints on system performance were demonstrated. Potential radio frequency interference was considered. The sensitivity of transmission system scale to variations in power source, transportation and orbital fabrication and assembly costs was also determined.

Stevens, G. H.; Schuh, R.

1976-01-01

440

Power processing methodology. [computerized design of spacecraft electric power systems  

NASA Technical Reports Server (NTRS)

Discussion of the interim results of a program to investigate the feasibility of formulating a methodology for the modeling and analysis of aerospace electrical power processing systems. The object of the total program is to develop a flexible engineering tool which will allow the power processor designer to effectively and rapidly assess and analyze the tradeoffs available by providing, in one comprehensive program, a mathematical model, an analysis of expected performance, simulation, and a comparative evaluation with alternative designs. This requires an understanding of electrical power source characteristics and the effects of load control, protection, and total system interaction.

Fegley, K. A.; Hansen, I. G.; Hayden, J. H.

1974-01-01

441

A Modular Laser Graphics Projection System  

NASA Astrophysics Data System (ADS)

WED Enterprises has designed and built a modular projection system for the presentation of animated laser shows. This system was designed specifically for use in Disney theme shows. Its modular design allows it to be adapted to many show situations with simple hardware and software adjustments. The primary goals were superior animation, long life, low maintenance and stand alone operation.

Newswanger, Craig D.

1984-05-01

442

Integration of wide area monitoring technology and enhancement of power system reliability in Baltic power system  

Microsoft Academic Search

Modern power system operation is monitored mainly by SCADA systems. Unfortunately, the receivable data is suitable only for system monitoring and control and is not applicable for detailed and complete investigation of fast system processes. Therefore, to enhance power system reliability in real time, more advanced technology is needed. The solution is WAMS (wide area monitoring system) system that uses

J. Kilter; A. Reinson

2008-01-01

443

Overload protection system for power inverter  

Microsoft Academic Search

An overload protection system for a power inverter utilized a first circuit for monitoring current to the load from the power inverter to detect an overload and a control circuit to shut off the power inverter, when an overload condition was detected. At the same time, a monitoring current inverter was turned on to deliver current to the load at

S. Nagano

1977-01-01

444

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

445

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

446

A genetic-based fuzzy logic power system stabilizer for multimachine power systems  

Microsoft Academic Search

This paper presents a novel approach to combine genetic algorithms (GA) with fuzzy logic systems to design a genetic-based fuzzy logic power system stabilizer (GFLPSS) for multimachine power systems. Incorporation of GA in fuzzy logic power system stabilizers (FLPSSs) design will significantly reduce the time consumed in the design process of FLPSSs. It is shown in this paper that the

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

1997-01-01

447

Design of Genetic Algorithm Based Fuzzy Logic Power System Stabilizers in Multimachine Power System  

Microsoft Academic Search

This paper presents the design of fuzzy logic power system stabilizers using genetic algorithms in multimachine power system. In the proposed fuzzy expert system, generator speed deviation and acceleration are chosen as input signals to fuzzy logic power system stabilizer. In this approach gains, centers of membership functions and the parameters of the fuzzy logic controllers have been tuned using

Manisha Dubey

2008-01-01

448

Decentralized sliding mode control technique based power system stabilizer (pss) for multimachine power system  

Microsoft Academic Search

Power system stabilizers (PSSs) are added to excitation system to enhance the damping of low frequency oscillations. In this paper, the design of PSS for multimachine power system (MMPS) using output feedback sliding mode control is proposed. The nonlinear model of a multimachine power system is linearized at various operating points and the linearized model of the plant is obtained.

Vitthal Bandal; B. Bandyopadhyay; A. M. Kulkarni

2005-01-01

449

Fuzzy Logic based Robust Power System Stabilizer for Multi-Machine Power System  

Microsoft Academic Search

Power system stabilizers (PSSs) are added to excitation system to enhance the damping during low frequency oscillations. This paper presents a study of fuzzy logic power system stabilizer (PSS) for stability enhancement of a multi-machine power system. In order to accomplish the stability enhancement, speed deviation (Deltaomega) and acceleration (Delta macromega) of the rotor of synchronous generator of multi machine

Rajeev Gupta; D. K. Sambariya; R. Gunjan

2006-01-01

450

Power electronics in electric utilities: Role of power electronics in future power systems  

Microsoft Academic Search

This paper presents a discussion of the role of power electronics in future power systems. The improvement of power semiconductors is held up as a major factor to the increased importance of this role. Power electronics applications for HVDC transmission is treated at some length.

N. G. Hingorani

1988-01-01

451

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

452

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

453

Nuclear Space Power Systems Materials Requirements  

NASA Astrophysics Data System (ADS)

High specific energy is required for space nuclear power systems. This generally means high operating temperatures and the only alloy class of materials available for construction of such systems are the refractory metals niobium, tantalum, molybdenum and tungsten. The refractory metals in the past have been the construction materials selected for nuclear space power systems. The objective of this paper will be to review the past history and requirements for space nuclear power systems from the early 1960's through the SP-100 program. Also presented will be the past and present status of refractory metal alloy technology and what will be needed to support the next advanced nuclear space power system. The next generation of advanced nuclear space power systems can benefit from the review of this past experience. Because of a decline in the refractory metal industry in the United States, ready availability of specific refractory metal alloys is limited.

Buckman, R. W.

2004-02-01

454

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

455

Automated diagnostics for aerospace power management systems  

SciTech Connect

Due to safety and mission criticality, aerospace power management systems require built in fault tolerance. Existing systems focus on hardware redundancy and lack the characteristics needed to provide rapid fault diagnostics and reconfiguration of power flow to critical users. Solid state power control (SSPC) electronics can provide faster switching times than electromechanical devices and when this technology is coupled with advanced software for diagnostics, a fault tolerant system design can be implemented. This paper describes a new project to integrate advanced SSPC electronics with newly available, knowledge-based diagnostic software in order to demonstrate the ability to detect, isolate and implement corrective action within a short period of time consistent with requirements for uninterrupted power. A fast embedded microprocessor will be used to run the diagnostic software and control power electronics. This project seeks to demonstrate the technology needed to enable a power management and distribution system to automatically compensate for faults in real time.

Granieri, M.N. [Giordano Automation Corp., Sparta, NJ (United States); Darty, M. [McDonnell Douglas Aerospace, Huntsville, AL (United States)

1995-12-31

456

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

457

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

458

Improved Power System of the Future  

E-print Network

This paper is intended to provide an insight into physics and engineering that can modernize electric power systems. Topics covered are Flexible ac transmission systems (FACTS), Custom Power, Greatly improved Capacitors, Electrical Insulation, Distribution Cables, Improved Polymeric Insulation, Underground Vault Explosions, Fault Location, Smart Cables, Neutral and Ground, Corrosion and Protection, Conventional Transformers, Compact Transformers, Ferroresonance, and Solid State Transformers.

Mario Rabinowitz

2003-04-22

459

International Space Station Power System Model Validated  

NASA Technical Reports Server (NTRS)

System Power Analysis for Capability Evaluation (SPACE) is a computer model of the International Space Station's (ISS) Electric Power System (EPS) developed at the NASA Glenn Research Center. This uniquely integrated, detailed model can predict EPS capability, assess EPS performance during a given mission with a specified load demand, conduct what-if studies, and support on-orbit anomaly resolution.

Hojnicki, Jeffrey S.; Delleur, Ann M.

2002-01-01

460

New modular power system controller architecture  

Microsoft Academic Search

This paper represents a new concept for a modular power system controller (PSC) architecture. It is based on a powerful PSC, distributed I\\/O modules and a highly flexible SW architecture. The communication between the modules and the PSC is done using CAN with sophisticated protocols, which allow plug and play functionality as well as new system functionalities.

R. Scherwey

2004-01-01

461

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

462

A GENETIC-BASED POWER SYSTEM STABILIZER  

Microsoft Academic Search

A Genetic-based Power System Stabilizer (GPSS) is presented in this paper to improve power system dynamic stability. The proposed GPSS parameters are optimized using Genetic Algorithms (GA). The main advantage of the proposed GPSS is that far less information than other design techniques is required without the need for linearization process. Time domain simulations of a synchronous machine subject to

M. A. ABIDO; Y. L. ABDEL-MAGID

1998-01-01

463

Distributed simulation for power system analysis including shipboard systems  

Microsoft Academic Search

Power systems are distributed in nature. Often they can be divided into sections or groups and treated separately. Terrestrial power systems are divided into separate utilities and are controlled by different regional transmission organization (RTO). Each RTO has detailed data for the area under its control, but only limited data and boundary measurements of the external network. Additionally, shipboard power

Jian Wu; Noel N. Schulz; Wenzhong Gao

2007-01-01

464

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

465

Power system emulation using a real time, 145 kW, virtual power system  

Microsoft Academic Search

The virtual power system is a real time, real power level, controllable sink\\/source used to emulate electrical machines and load systems connected to a system which requires testing. This can significantly aid in the development and testing of power systems. An earlier development, the virtual machine concentrated solely on the emulation of a low power (7.5 kW) induction machine. However,

M. Armstrong; D. J. Atkinson; A. G. Jack; S. Turner

2005-01-01