Sample records for stand-alone power systems

  1. Stand-alone photovoltaic energy storage system with maximum power point tracking

    Microsoft Academic Search

    V. A. Pacheco; L. C. Freitas; E. A. A. Coelho; V. J. Farias

    2003-01-01

    This digests deals with the study of a stand-alone photovoltaic system, which is able to extract the maximum power from photovoltaic array for all solar intensity conditions and to provide output voltage regulation. The proposed system consists of a DC-DC converter in combination with battery energy storage in a simple structure. Operating principle and control strategy are described. Digital simulation

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

    Microsoft Academic Search

    Caisheng Wang; M. Hashem Nehrir

    2008-01-01

    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

  3. Stand alone solar powering for fiber-in-the-loop systems

    Microsoft Academic Search

    T. H. Kimsey; K. M. Mistry; R. C. Estes; J. R. McKay; T. M. Taylor

    1992-01-01

    A key concern in fiber-in-the-loop systems is reliable powering of end-loop optical network units (ONUs). The technical and economical feasibility of using stand alone solar-photovoltaic (SAS) systems for powering these units is examined. Arrays of photovoltaic cells located at or near the ONU are connected to a battery and the ONU electronics. During normal sunlight conditions, electricity from the panels

  4. Dynamic modeling and sizing optimization of stand-alone photovoltaic power systems using hybrid energy storage technology

    Microsoft Academic Search

    Chun-Hua Li; Xin-Jian Zhu; Guang-Yi Cao; Sheng Sui; Ming-Ruo Hu

    2009-01-01

    Economic and environmental concerns over fossil fuels encourage the development of photovoltaic (PV) energy systems. Due to the intermittent nature of solar energy, energy storage is needed in a stand-alone PV system for the purpose of ensuring continuous power flow. Three stand-alone photovoltaic power systems using different energy storage technologies are studied in this paper. Key components including PV modules,

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

    NASA Astrophysics Data System (ADS)

    Itako, Kazutaka; Mori, Takeaki

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

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

    Microsoft Academic Search

    L. L. Bucciarelli Jr.

    1984-01-01

    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,

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

    NASA Astrophysics Data System (ADS)

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

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

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

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

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

    NASA Technical Reports Server (NTRS)

    Philippi, T. M.

    1981-01-01

    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.

  11. Power management strategies for a stand-alone power system using renewable energy sources and hydrogen storage

    Microsoft Academic Search

    Dimitris Ipsakis; Spyros Voutetakis; Panos Seferlis; Fotis Stergiopoulos; Costas Elmasides

    2009-01-01

    A stand-alone power system based on a photovoltaic array and wind generators that stores the excessive energy from renewable energy sources (RES) in the form of hydrogen via water electrolysis for future use in a polymer electrolyte membrane (PEM) fuel cell is currently in operation at Neo Olvio of Xanthi, Greece. Efficient power management strategies (PMSs) for the system have

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

    Microsoft Academic Search

    Yukihiro Ozaki; Masafumi Miyatake; Daisuke Iwaki

    2010-01-01

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

  13. Stand alone wind power generating system employing permanent magnet synchronous generator

    Microsoft Academic Search

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

    2008-01-01

    In this paper, a distributed generation based on stand alone wind energy conversion system (WECS) using a permanent magnet synchronous generator (PMSG) is proposed with a solid state voltage and frequency (VF) controller. A high efficiency WECS is realised using a PMSG driven by a wind turbine with a gear system. The controller consists of IGBTs (insulated gate bipolar transistors)

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

    Microsoft Academic Search

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

    2004-01-01

    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.

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

    SciTech Connect

    Not Available

    1980-07-01

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

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

    Microsoft Academic Search

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

    2010-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  18. Developed algorithm of maximum power tracking for stand-alone photovoltaic system

    SciTech Connect

    Nafeh, A.E.A.; Fahmy, F.H. [Electronics Research Inst., Cairo (Egypt). National Research Center; Mahgoub, O.A.; El-Zahab, E.M.A. [Cairo Univ., Giza (Egypt). Faculty of Engineering

    1998-01-01

    The rapid increase in the cost of conventional energy sources leads to the use of nonconventional energy sources. The photovoltaic (PV) is one nonconventional source that is safe, reliable, and environmentally healthy. However, the PV system is expensive and needs a large area to operate. To solve these disadvantages, it is necessary to operate at the maximum power point (MPP) of the array. This article presents a new maximum power tracking algorithm based on the incremental conductance algorithm, which successfully operates even in cases of rapidly changing atmospheric conditions. The developed algorithm depends on the relationship between the load line and the tangent line angles of the I-V characteristic curve. A simulation program was designed to investigate the performance of the developed algorithm using mathematical models for the different system components. The simulation led to a good realization of the algorithm.

  19. A novel maximum power point tracking algorithms for stand-alone photovoltaic system

    Microsoft Academic Search

    Shiqiong Zhou; Longyun Kang; Jing Sun; Guifang Guo; Bo Cheng; Binggang Cao; Yiping Tang

    2010-01-01

    A novel control algorithm, namely subsection adaptive hill climbing method (SSAHC), for seeking the maximum power point (MPP)\\u000a of a photovoltaic (PV) panel for any temperature and solar radiation level is proposed. The algorithm is thus a combination\\u000a of the subsection and adaptive hill climbing methods. In this algorithm, the characteristic curve of power-voltage of PV panel\\u000a was divided into

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

    Microsoft Academic Search

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

    2005-01-01

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

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

    Microsoft Academic Search

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

    2006-01-01

    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

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

    E-print Network

    Lavaei, Javad

    the solar radiation of the inclined solar panels. All these data act as the input of the mathematical model of solar panels and wind turbine to simulate the system. The minimization of the objective cost function. The most popular integration of renewable energy is through wind turbine and solar panels. Figure 2 shows

  3. Photovoltaic stand-alone modular systems, phase 2

    Microsoft Academic Search

    G. J. Naff; N. A. Marshall

    1983-01-01

    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,

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

    Microsoft Academic Search

    G. J. Naff; N. A. Marshall

    1983-01-01

    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,

  5. Modular photovoltaic stand-alone systems. Phase I. Final report

    Microsoft Academic Search

    G. J. Naff; N. A. Marshall

    1983-01-01

    A Phase I program plan was developed and implemented leading to the detail design of an optimized low power, reliable, low life cycle cost stand-alone photovoltaic (PV) system. Modularity was established in power increments of 0.25 kWp in the range of 0.5 to 16 kWp. The investigations, analyses and designs addressed the balance-of-systems (BOS) elements and subsystems, the PV cells

  6. 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

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

    2000-01-01

    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

  7. Generator solutions for stand alone pico-electric power plants

    Microsoft Academic Search

    D. Fodorean; L. Szabo; A. Miraoui

    2009-01-01

    This paper presents several solutions for stand alone pico-electric power plants, which are used for electric energy production from water power. Up to now, the induction and permanent magnet synchronous generators were studied and presented as best variants for small power generation. Another topology is proposed here: a hybrid excited synchronous generator, based on two different types of excitation field:

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

    Microsoft Academic Search

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

    2008-01-01

    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

  9. Modular photovoltaic stand-alone systems: Phase 1

    NASA Astrophysics Data System (ADS)

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

    1983-02-01

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

  10. Modular photovoltaic stand-alone systems. Phase I. Final report

    SciTech Connect

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

    1983-02-01

    A Phase I program plan was developed and implemented leading to the detail design of an optimized low power, reliable, low life cycle cost stand-alone photovoltaic (PV) system. Modularity was established in power increments of 0.25 kWp in the range of 0.5 to 16 kWp. The investigations, analyses and designs addressed the balance-of-systems (BOS) elements and subsystems, the PV cells and modules having been designated as an available technology conforming to JPL Block IV, Specification 5101-830. A survey of existing BOS developments was conducted and state-of-the-art BOS designs were generated, evaluated and used in cost trade-offs. A matrix of BOS attributes led to the selection of seven conceptual designs consisting of various BOS elements or combinations thereof. Three of the conceptual designs were selected for further evaluation, preparation of preliminary designs and refinements in life cycle cost trade-offs. The design emerging as the most optimum configuration was selected as the final design candidate. Detail drawings, equipment listings, procurement specifications, test procedures, and production cost estimates were developed in preparation for the Phase II breadboarding of critical control and load management circuits and for the development of an engineering model. Results of the study and designs showed that lead acid batteries are the only practical, near term, available source for electrical energy storage, and, for stand-alone PV power systems, are the major cost driver contributing between 60 to 70% of total system 20 year life cycle costs. For the established range of performance there were only small cost variances between different designs of a given element. It was also shown that properly adjudicated regulation and load management contribute significantly both to reductions in system sizing and improvements in battery life.

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

    Microsoft Academic Search

    E. Ofry; A. Braunstein

    1983-01-01

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

  12. Multiport DC\\/DC Converter for Stand-alone Photovoltaic Lighting System with Battery Storage

    Microsoft Academic Search

    Shengyong Liu; Xing Zhang; Haibin Guo; Jun Xie

    2010-01-01

    Photovoltaic energy has nowadays an increased importance in electrical power applications. However, the output power provided via the photovoltaic conversion process depends on solar irradiation and temperature. Therefore a multiple-input DC\\/DC converter is proposed for stand-alone photovoltaic lighting system with battery storage in this paper. Compared with the traditional stand-alone photovoltaic system, which merely use one muti-input biderictional DC\\/DC converter

  13. Photovoltaic stand-alone modular systems, phase 2

    NASA Astrophysics Data System (ADS)

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

    1983-07-01

    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.

  14. Photovoltaic stand-alone modular systems, phase 2

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

  15. A stochastic method for stand-alone photovoltaic system sizing

    SciTech Connect

    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

    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)

  16. Sizing handbook for stand-alone photovoltaic\\/storage systems

    Microsoft Academic Search

    R. N. Chapman

    1987-01-01

    This report details the use and development of a simplified sizing technique for stand-alone photovoltaic\\/storage systems. The array size and storage capacity are chosen to achieve the required loss-of-load probability (LOLP). The LOLP represents the level of confidence at which the system will satisfy the load. An LOLP of 0 means that the load will always be satisfied, and an

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

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    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.

  18. Modular stand-alone monitor and control system (SAMAC)

    SciTech Connect

    Kieffer, J.

    1980-10-01

    Large high energy physics experiments require constant monitoring and control of the numerous components of the particle detector apparatus. This paper describes a basic hardware configuration which has been designed to satisfy the monitoring and control requirements of the many different experimental setups. The system is designed to operate in the stand-alone mode, and may be interfaced to a host computer via CAMAC. The entire system is modular so that it can be easily tailored to an individual experiment. The items monitored and/or controlled may include gas pressures, temperatures, magnetic fields, high and low voltages, and system status or safety information.

  19. Sizing of photovoltaic sources and storage devices for stand-alone power plants

    Microsoft Academic Search

    R. Rizzo; L. Piegari; P. Tricoli; C. Munteanu; V. Topa

    2009-01-01

    The paper deals with the sizing a PV based source capable of working stand alone. The objective in the design of a PV system is to provide reliable power supply to the load without interruptions and without wasting energy. Several methods for evaluating the achievement of the above objective were found in the literature. In the paper authors proposes a

  20. The control strategies for photovoltaic regulators applied to stand-alone systems

    Microsoft Academic Search

    V. Salas; M. J. Manzanas; A. Lazaro; A. Barrado; E. Olias

    2002-01-01

    This paper presents the study of the control strategies enclosed in photovoltaic charge control, including maximum power point trackers (MPPTs). It was simulated and evaluated using simulating tool Simulink®. It is supposed to be integrated on a photovoltaic stand-alone systems where it is very important to maximize the efficiency of its power source: the array of photovoltaics panels.

  1. Unitised Regenerative Fuel Cells for Stand-Alone Photovoltaic Generation Systems

    Microsoft Academic Search

    D. ARDITO; S. CONTI; S. RAITI; U. VAGLIASINDI

    2005-01-01

    Photovoltaic (PV) stand-alone applications are able to provide electricity to isolated loads in remote areas and they are installed particularly where grid extensions would be uneconomical. However, the limitation in power availability of PV systems due to the variability of solar radiation requires the use of storage systems in order to supply loads with adequate reliability levels. The storage systems

  2. Distributed Energy Management for Stand-Alone Photovoltaic System with Storages

    Microsoft Academic Search

    Jae Hoon Cho; Dong Hwa-Kim

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

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

    Microsoft Academic Search

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

    2010-01-01

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

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

    Microsoft Academic Search

    M. J. Khan; M. T. Iqbal

    2005-01-01

    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

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

    Microsoft Academic Search

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

    2007-01-01

    The Stand-alone WIreless Magnetometer System (SWIMS) is intended to serve as a technology suitable for large scale deployment for magnetometer networks in sub-auroral latitudes with minimal logistical support and maintenance. SWIMS is based on a new magnetometer developed and licensed by JHU\\/APL. A SWIMS installation will consist of up to three solar\\/battery powered Sensor Modules (SM) each equipped with a

  6. Video tracking algorithm of long-term experiment using stand-alone recording system

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Jen; Li, Yan-Chay; Huang, Ke-Nung; Jen, Sun-Lon; Young, Ming-Shing

    2008-08-01

    Many medical and behavioral applications require the ability to monitor and quantify the behavior of small animals. In general these animals are confined in small cages. Often these situations involve very large numbers of cages. Modern research facilities commonly monitor simultaneously thousands of animals over long periods of time. However, conventional systems require one personal computer per monitoring platform, which is too complex, expensive, and increases power consumption for large laboratory applications. This paper presents a simplified video tracking algorithm for long-term recording using a stand-alone system. The feature of the presented tracking algorithm revealed that computation speed is very fast data storage requirements are small, and hardware requirements are minimal. The stand-alone system automatically performs tracking and saving acquired data to a secure digital card. The proposed system is designed for video collected at a 640×480 pixel with 16 bit color resolution. The tracking result is updated every 30 frames/s. Only the locomotive data are stored. Therefore, the data storage requirements could be minimized. In addition, detection via the designed algorithm uses the Cb and Cr values of a colored marker affixed to the target to define the tracked position and allows multiobject tracking against complex backgrounds. Preliminary experiment showed that such tracking information stored by the portable and stand-alone system could provide comprehensive information on the animal's activity.

  7. Stand-alone photovoltaic (PV) powered electrochromic window

    DOEpatents

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

    1995-01-01

    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.

  8. Stand-alone photovoltaic (PV) powered electrochromic window

    DOEpatents

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

    1995-01-24

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

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

    Microsoft Academic Search

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

    2000-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

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

  12. Peer-produced systems can achieve what might be infeasible for stand-alone systems developed

    E-print Network

    Zhao, Feng

    , parking occupancy counter, weather monitoring home system, or heart rate monitor for runners. HoweverPeer-produced systems can achieve what might be infeasible for stand-alone systems developed all the compositions individually. This kind of approach is at work in systems produced by labs

  13. Battery capacity tests evaluation for stand-alone photovoltaic systems

    Microsoft Academic Search

    M. K. C. Marwali; N. M. Maricar; S. K. Shrestha

    2000-01-01

    Charge controllers are included in most photovoltaic systems to protect the batteries from overcharge and\\/or excessive discharge. However determining the state-of charge of a battery is not easy because most battery systems utilize multiple battery cells in series, e.g. 48 and 120 V battery systems will normally consists of 24 and 60 cells in series, respectively. One controller is normally

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

    E-print Network

    Deymier, Pierre

    COMPRESSED-AIR ENERGY STORAGE SYSTEMS FOR STAND-ALONE OFF-GRID PHOTOVOLTAIC MODULES Dominique materials, flywheels, pumped hydro (PH), superconducting magnetic energy storage (SMES) and compressed air-grid alternative to the large-scale compressed air energy storage systems we propose to examine the viability

  15. Research on BiDirectional DC-DC Converter For a Stand-Alone Photovoltaic Hybrid Energy Storage System

    Microsoft Academic Search

    Xie Jun; Zhang Xing; Zhang Chongwei; Wang Chengyue

    2010-01-01

    A novel stand-alone photovoltaic ultracapacitor\\/battery hybrid energy storage system is proposed. Compared with the traditional one, this system has high power density and high energy density, prolong the lifetime of battery, achieve the system more efficient and reliable etc. A digital control system for multiple-input bi-directional dc-dc converter is designed and implemented. Software and hardware implementation issuses are described .

  16. A stand-alone photovoltaic supercapacitor battery hybrid energy storage system

    Microsoft Academic Search

    M. E. Glavin; P. K. W. Chan; S. Armstrong; W. G. Hurley

    2008-01-01

    Most of the stand-alone photovoltaic (PV) systems require an energy storage buffer to supply continuous energy to the load when there is inadequate solar irradiation. Typically, Valve Regulated Lead Acid (VRLA) batteries are utilized for this application. However, supplying a large burst of current, such as motor startup, from the battery degrades battery plates, resulting in destruction of the battery.

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

    Microsoft Academic Search

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

    2002-01-01

    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

  18. Optimal hydrogen production in a stand-alone renewable energy system

    Microsoft Academic Search

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

    2005-01-01

    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

  19. A simplified technique for designing least cost stand-alone PV\\/storage systems

    Microsoft Academic Search

    Richard N. Chapman

    1987-01-01

    A new design technique is presented for stand-alone photovoltaic\\/storage systems that accounts for the year-to-year variations in insolation and yet requires only the average monthly horizontal insolation as input. The array and storage sizes are governed by the desired loss-of-load probability (LOLP), which represents the fraction of the demand not met during the system's lifetime. The designer can size for

  20. Development of sizing nomograms for stand-alone photovoltaic\\/storage systems

    Microsoft Academic Search

    R CHAPMAN

    1989-01-01

    This paper describes the development of a simplified technique for sizing stand-alone photovoltaic\\/storage systems. The sizing criterion is the long-term loss-of-load probability which is the fraction of the total energy demand that the photovoltaic system will not be able satisfy over a 23-year period. The technique was derived using 23 years of hourly insolation data from 20 US weather stations.

  1. Development of sizing nomograms for stand-alone photovoltaic\\/storage systems

    Microsoft Academic Search

    R. N. Chapman

    1987-01-01

    This paper described the development of a simplified technique for sizing stand-alone photovoltaic\\/storage systems. The sizing criterion is the long-term loss-of-load probability which is the fraction of the total energy demand that the photovoltaic system will not be able to satisfy over a 23 year period. The technique was derived using 23 years of hourly insolation data from 20 US

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

    Microsoft Academic Search

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

    2007-01-01

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

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

    SciTech Connect

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

    1994-06-01

    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.

  4. Dynamic response of a stand-alone wind energy conversion system with battery energy storage to a wind gust

    SciTech Connect

    Borowy, B.S.; Salameh, Z.M. [Univ. of Massachusetts, Lowell, MA (United States). Dept. of Electrical Engineering] [Univ. of Massachusetts, Lowell, MA (United States). Dept. of Electrical Engineering

    1997-03-01

    A mathematical model of each element of the Stand-Alone Wind Energy Conversion System is developed. The model variables are expressed in the d-q rotor reference frame. The wind turbine was considered as the only source of power in this study. Using this model the system response to a recorded wind gust is investigated by calculating the generator current, the rectifier current, the load current, the battery charging current, and the battery voltage. The calculated results are then verified by comparing them with the actual values obtained from the data acquisition system. A good agreement was achieved between the experimental and the analytical results.

  5. System Simulation by Recursive Feedback: Coupling A Set of Stand-Alone Subsystem Simulations

    NASA Technical Reports Server (NTRS)

    Nixon, Douglas D.; Hanson, John M. (Technical Monitor)

    2002-01-01

    Recursive feedback is defined and discussed as a framework for development of specific algorithms and procedures that propagate the time-domain solution for a dynamical system simulation consisting of multiple numerically coupled self-contained stand-alone subsystem simulations. A satellite motion example containing three subsystems (other dynamics, attitude dynamics, and aerodynamics) has been defined and constructed using this approach. Conventional solution methods are used in the subsystem simulations. Centralized and distributed versions of coupling structure have been addressed. Numerical results are evaluated by direct comparison with a standard total-system simultaneous-solution approach.

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

    NASA Technical Reports Server (NTRS)

    Nixon, Douglas D.; Ryan, Stephen G. (Technical Monitor)

    2002-01-01

    Recursive feedback is defined and discussed as a framework for development of specific algorithms and procedures that propagate the time-domain solution for a dynamical system simulation consisting of multiple numerically coupled, self-contained, stand-alone subsystem simulations. A satellite motion example containing three subsystems (orbit dynamics, attitude dynamics, and aerodynamics) has been defined and constructed using this approach. Conventional solution methods are used in the subsystem simulations. Centralized and distributed versions of coupling structure have been addressed. Numerical results are evaluated by direct comparison with a standard total-system, simultaneous-solution approach.

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

    SciTech Connect

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

    2009-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  9. A two-stage converter based controller for a stand alone wind energy system used for remote applications

    Microsoft Academic Search

    Anubhav Sinha; Devesh Kumar; P. Samuel; R. Gupta

    2008-01-01

    This paper proposes a control strategy for tracking and maintaining a constant voltage and frequency across remote loads through stand alone variable speed wind energy conversion system (VSWECS). The system consists of a variable speed wind turbine coupled to a permanent magnet synchronous generator (PMSG). Output of the PMSG is first converted into a fixed DC voltage using a buck

  10. Using the Mars Ascent Vehicle as a Stand-Alone Sample Return System

    NASA Astrophysics Data System (ADS)

    Lo, A. S.; Trinidad, M.; Guilmette, T.; Segura, T.

    2012-03-01

    Northrop Grumman is participating in a Phase I study of a Mars Ascent Vehicle (MAV) design. As part of internal R&D, we conducted a feasibility study of using the MAV as a stand-alone sample return vehicle for the Moon. We discuss our results.

  11. Honeywell Parallon Stand-alone Tests Honeywell Stand-alone Tests

    E-print Network

    Appendix E Honeywell Parallon Stand-alone Tests 5/2/2001 #12;Honeywell Stand-alone Tests 5 Figure E-1: Ramp Down Tests ­ Power and Shaft Speed ­ kW and kVAR Steps #12;Honeywell Stand-alone Tests 5 Down Tests ­ Power and Turbine Exit Temperature ­ kW and kVAR Steps #12;Honeywell Stand-alone Tests 5

  12. Dynamic Voltage Stabilization of Stand-Alone Wind Energy Schemes

    Microsoft Academic Search

    A. M. Sharafe; A. S. Aljankawey; I. H. Altas

    2007-01-01

    Voltage stability is one of the serious problems in stand- alone wind energy schemes utilizing the induction generator especially under wind excursion and load variation. This paper presents a novel low cost Modulated Power Filter Compensator FACTS based-MPFC for a stand-alone green energy renewable wind energy conversion systems using self-excited low cost squirrel-cage induction generator (SEIG) driven by a wind

  13. Capstone LP Stand-alone Tests Capstone Stand-alone Tests

    E-print Network

    Appendix D Capstone LP Stand-alone Tests 3/20/2001 #12;Capstone Stand-alone Tests 3/20/2001 -5: Ramp Tests ­ Power and Shaft Speed ­ 4 kW Steps #12;Capstone Stand-alone Tests 3/20/2001 -5,000 0 5ExitTemp(degC) Real Power3Ø (W) Reactive Power3Ø (VAR) Turbine Exit Temp (°C) Figure D-2: Ramp Tests ­ Power

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

    Microsoft Academic Search

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

    2009-01-01

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

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

    Microsoft Academic Search

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

    1996-01-01

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

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

    E-print Network

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

    2004-01-01

    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...

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

    E-print Network

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

    2004-01-01

    With industrial development the problem of energy shortage is more and more aggravating. The photovoltaic (PV) systems are rapidly expanding and have increasing in electric power technology and regarded as the green energy of the new century control...

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

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

    Microsoft Academic Search

    Netra Gyawali; Yasuharu Ohsawa

    2010-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Nickum, J. D.

    1978-01-01

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

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

    SciTech Connect

    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

    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)

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

    E-print Network

    Paris-Sud XI, Université de

    optimization. Nomenclature Pt Wind turbine mechanical power (W) A Wind turbine blade sweeping surface (m²) R Wind turbine blade radius (m) Cp Wind turbine power coefficient (­) Tip-speed ratio (­) Wind turbine

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

    NASA Technical Reports Server (NTRS)

    Hagedorn, N. H.

    1981-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Hagedorn, N. H.

    1981-01-01

    A 1-kW preprototype redox storage system that has undergone characterization tests and been operated as the storage device for a 5-kW (peak) photovoltaic array is described and performance data are presented. Loss mechanisms are discussed, and simple design changes leading to appreciable increases in efficiency are suggested. The effects on system performance of nonequilibrium between the predominant species of complexed chromic ion in the negative electrode reactant solution are summarized. It is noted that with the aid of the prototype system, control concepts have been shown to be valid and trouble free and some insight has been gained into interactions at the mutual interfaces of the redox system, the photovoltaic array, the load, and the control devices.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  6. A low-cost stand-alone real-time multi-channel frequency monitoring system

    Microsoft Academic Search

    M. Abdallah; O. Elkeelany

    2010-01-01

    In this paper, an affordable sophisticated standalone real-time multi-channel analog signal Acquisition and Frequency Detection and\\/or Monitoring (A FREDOM) system is proposed. The A FREDOM is used to acquire multi-channel real-time analog signals. It also detects and monitors their frequencies. Any change in any channel frequency is reported. A proper action is taken place upon frequency change. The A FREDOM

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

    E-print Network

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

  8. Human Uniqueness: Standing Alone?

    E-print Network

    Davison, Andrew Paul

    2015-06-18

    in the universe, our sense of its likeliness has been transformed. As of May 2015, 1924 ‘exoplanets’ (planets outside our solar system) are listed on the Extrasolar Planets Encyclopedia.16 A thorough study of the proportion of stars with orbiting planets... , but that it is also likely.15 Until recent decades, such discussion was purely speculative. In 1988, however, the first detection was made of a planet around another star (that has subsequently been confirmed). While life has not been discovered elsewhere...

  9. Why icons cannot stand alone

    Microsoft Academic Search

    Katherine Haramundanis

    1996-01-01

    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.

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

    Microsoft Academic Search

    Essam Sh. Mohamed; G. Papadakis

    2004-01-01

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

  11. Photovoltaic stand-alone applications reading list

    NASA Astrophysics Data System (ADS)

    1985-08-01

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

  12. Standing alone with prosodic help*

    PubMed Central

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

    2013-01-01

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

  13. A Single-Crate Stand-Alone CAMAC Control System for a Negative Ion Source Test Facility

    Microsoft Academic Search

    Raymond C. Juras; Norval F. Ziegler

    1979-01-01

    A single-crate CAMAC system was configured to control a negative ion source development facility at ORNL and control software was written for the crate microcomputer. The software uses inputs from a touch panel and a shaft encoder to control the various operating parameters of the test facility and uses the touch panel to display the operating status. Communication to and

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

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    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.

  15. Solar photovoltaics: Stand alone applications

    NASA Astrophysics Data System (ADS)

    Deyo, J. N.

    1980-11-01

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

  16. Creating a stand-alone fundraising foundation.

    PubMed

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

    2012-10-01

    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

  17. Capstone Low Pressure Grid-connect Tests Capstone LP Stand-alone Tests

    E-print Network

    Appendix B Capstone Low Pressure Grid-connect Tests 10/25/2000 #12;Capstone LP Stand-alone Tests 10) Figure B-1: Power and Shaft Speed ­ 10 kW Steps #12;Capstone LP Stand-alone Tests 10/25/2000 0 5000 10000) Figure B-2: Power and Turbine Exit Temperature ­ 10 kW Steps #12;Capstone LP Stand-alone Tests 10

  18. A stand-alone peristaltic micropump based on piezoelectric actuation

    Microsoft Academic Search

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

    2007-01-01

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

  19. Stand Alone Spacecraft Attitude Determination Using GPS Signals

    Microsoft Academic Search

    S. Purivigraipong

    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

  20. A new method for estimating insolation based on PV-module currents in a cluster of stand-alone solar systems

    Microsoft Academic Search

    Frans Nieuwenhout; Nico van der Borg; Wilfried van Sark; Wim Turkenburg

    2007-01-01

    In order to evaluate the performance of solar home systems (SHSs), data on local insolation is a prerequisite. We present a new method to estimate insolation if direct measurements are unavailable. This method comprises estimation of daily irradiation by correlating photovoltaic (PV) module currents from a number of SHSs, located a few kilometres apart. The method was tested with a

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  2. PORTABLE STAND-ALONE INSTRUMENTATION FOR INTRACELLULAR IN VITRO RECORDINGS

    E-print Network

    by two coin batteries and directly connected to a traditional intracellular glass electrode. The brain amplifier and the portable stand-alone circuit, intracellular signals are acquired for more than 20 hours higher than 30. Signals recorded with the stand-alone circuit are shown to reliably reproduce

  3. Collaborative Eclipse Plug-in Integration Architecture for stand alone

    E-print Network

    Jones, Edward

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

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

    Microsoft Academic Search

    Remus Teodorescu; Frede Blaabjerg

    2004-01-01

    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

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

    Microsoft Academic Search

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

    2008-01-01

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

  6. 21 CFR 801.50 - Labeling requirements for stand-alone software.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...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...

  7. Capstone/Capstone Parallel Stand-alone Tests Capstone/Capstone Parallel Tests

    E-print Network

    Appendix G Capstone/Capstone Parallel Stand-alone Tests 4/17/2001 #12;Capstone/Capstone Parallel;Capstone/Capstone Parallel Tests 4/17/2001 -5,000 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40 and Load Bank Power ­ Power and Line-to-Neutral Voltage #12;Capstone/Capstone Parallel Tests 4/17/2001 -5

  8. Hanford tank initiative cone penetrometer stand alone grouting module

    SciTech Connect

    CALLAWAY, W.S.

    1998-10-15

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

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

    NASA Astrophysics Data System (ADS)

    Sakhare, Abhishek; Davari, Asad; Feliachi, Ali

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

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

    Microsoft Academic Search

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

    2010-01-01

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

  11. Probabilistic modeling of solar power systems

    Microsoft Academic Search

    Fayssal M. Safie

    1989-01-01

    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

  12. Market assessment of photovoltaic power systems for agricultural applications in Nigeria

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

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

    Microsoft Academic Search

    R. Bonert; G. Hoops

    1990-01-01

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

  14. Design Considerations for Stand-alone Haptic Interfaces Communicating via UDP Protocol

    E-print Network

    Tan, Hong Z.

    Design Considerations for Stand-alone Haptic Interfaces Communicating via UDP Protocol Ryan M was motivated by the need for high-speed communication between a stand-alone haptic interface and an external capable of both controlling a variety of different haptic interfaces and communicating via Ethernet

  15. Design Considerations for Stand-alone Haptic Interfaces Communicating via UDP Protocol

    E-print Network

    Tan, Hong Z.

    Design Considerations for Stand-alone Haptic Interfaces Communicating via UDP Protocol Ryan M for high speed communication between a stand-alone haptic interface and a computer running haptic rendering. Traylor,1 Danny Wilhelm,1 Bernard D. Adelstein2 and Hong Z. Tan1 1 Haptic Interface Research Laboratory

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

    Microsoft Academic Search

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

    2005-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

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

  18. Photovoltaic \\/ thermal system for stand-alone operation

    Microsoft Academic Search

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

    2008-01-01

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

  19. Stand-alone microprocessor controlled fast sweep Langmuir probe driver

    NASA Astrophysics Data System (ADS)

    Cheetham, A. D.; Davidson, L.; Jakobsen, J.; Lund, T.; Rayner, J. P.

    1997-09-01

    This article describes a power supply and data logger for a Langmuir probe interfaced to a personal computer. The system provides a voltage sweep range from -125 to +100 V in 100 steps in a time ˜0.15 s. Restricted sweep ranges and single point operation are also possible. Probe current measurements are in the range from -1.0 to +100 mA with a precision of 5 ?A on the most sensitive range, while the voltage may be set with a precision of 56 mV. Novel features of the system include: the use of integrate-and-dump techniques to implement the process of analog-to-digital conversion and to provide effective noise suppression; a solution to the problem of floating the power supply on top of the potential developed across the grounded current sensing resistor based on the power supply rejection ratio characteristics of a high voltage operational amplifier; and the development of an interface and control board employing the GPIB protocol to communicate with a host computer. Successful operation of the system has been demonstrated in the electrically noisy environment of a helicon plasma source.

  20. The purchase order does not stand alone as formal contract obligation, HCFA says.

    PubMed

    Decker, R

    1992-07-01

    A controversy has developed over whether a purchase order for a large item of movable equipment amounts to an obligation under the new Medicare Capital Prospective Payment System (PPS) of the Health Care Financing Agency (HCFA). HCFA's draft revision to the Provider Reimbursement Manual indicates that a p.o. doesn't stand alone as a binding contract and that such purchases should be by formal contract. Some hospital trade groups argue that, in the normal practice of most hospitals, the p.o. is a contract to buy and should be treated as an obligation under the Medicare rules. In this dialogue, Dr. Decker addresses the issues of this controversy. PMID:10119972

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    We show the feasibility of waveforms and coseismic displacements real-time estimation at few centimeters accuracy level by a stand-alone dual-frequency GPS receiver through a variometric approach. This approach is based on the time single-differences of the carrier phase observations collected at high-rate (1Hz or more) by a stand-alone receiver and on the standard GPS broadcast products (orbits, clocks). Time series of epoch-by-epoch displacements are estimated at first; then, they can be summed over the interval (limited to few minutes) when the earthquake occurs, provided the collected observations are continuous. The estimation biases due to mismodeling accumulate over time and display as a trend, which can be considered linear and easily removed thanks to the shortness of the interval. Since the proposed approach does not require any additional technological complexity nor centralized data analysis, in principle it can be embedded into the receiver firmware, providing also a significant contribution to tsunami warning systems. After a preliminary test regarding a simulated example, the effectiveness has been proven over real data. In details, we have analyzed the 1Hz GPS data recorded by the IGS station BREW during the Denali Fault, Alaska earthquake (Mw 7.9, November 3, 2002, 22:12:41 UTC) and the 5 Hz data collected by some stations included into the UNAVCO-Plate Boundary Observatory network and California Real Time Network (CRTN) during the Baja California, Mexico earthquake (Mw 7.2, April 04, 2010, 22:40:42 UTC). The comparisons with results obtained with different strategies show an agreement within few centimeters; examples for Baja California earthquake (waveforms for stations P496 e P744, to be compared with http://www.unavco.org/research_science/science_highlights/2010/M7.2-Baja.html) are shown in Figures 1 and 2. Fig. 1 - P496 Fig. 2 - P744

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

    E-print Network

    Tolbert, Leon M.

    technologies in PV utilization. Multilevel voltage source inverters offer several advantages comparedFundamental Frequency Modulated Multilevel Inverter for Three-Phase Stand-Alone Photovoltaic-6472, USA Abstract - This paper presents a fundamental frequency modulated multilevel inverter scheme

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

    NASA Technical Reports Server (NTRS)

    Tomlinson, Bill

    1989-01-01

    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.

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

    PubMed

    Mustafa, A

    1995-01-01

    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

  5. Performance evaluation of stand alone hybrid PV-wind generator

    NASA Astrophysics Data System (ADS)

    Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H.; Yahaya, M. S.

    2015-05-01

    This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.

  6. High-responsivity thermoelectric infrared detectors with stand-alone sub-micrometer polysilicon wires

    NASA Astrophysics Data System (ADS)

    Modarres-Zadeh, Mohammad J.; Abdolvand, Reza

    2014-12-01

    A novel high-responsivity uncooled thermoelectric (TE) infrared (IR) detector is designed, fabricated and characterized. This detector features a single stand-alone polysilicon-based thermocouple (without a supporting membrane) covered by an umbrella-like optical cavity IR absorber. It is proved that the highest responsivity in the developed detectors can be achieved with only one thermocouple. Using a single thermocouple also results in a low resistance detector, which consequently limits the Johnson noise (e.g. less than 30?nv/?Hz in this work). Since the sub-micrometer polysilicon TE wires are the only heat path from the hot junction to the substrate, a superior thermal isolation is achieved. A responsivity of 1800?V?W?1 and a detectivity of 2* 108 (cm?Hz1/2 W?1) are measured from a 20? × ?20?µm detector comparable to the performance of detectors used in commercial focal planar arrays [1]. This performance in a compact and manufacturable design elevates the position of thermoelectric IR sensors as a candidate for low-power, high performance and inexpensive focal planar arrays.

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

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

  9. Large power PWM IGBT converter for shaft alternator systems

    Microsoft Academic Search

    Giacomo Marina; E. Gatti

    2004-01-01

    The use of shaft alternators in marine application is well known as a convenient and efficient way to supply all the electrical loads of a ship with two main purposes: sharing active and reactive power with the auxiliary generators installed on board and operating in stand alone configuration when the ship travels at cruising speed. An innovative shaft alternator system

  10. Maintaining the Dialogue: Joint Involvement in a Stand-Alone CD-Rom Chinese Course.

    ERIC Educational Resources Information Center

    Orton, Jane

    2003-01-01

    Presents a stand-alone CD-Rom version of a Web-based course in Modern Standard Chinese and addresses the problem of losing opportunities for negotiation in joint involvement episodes with teachers and peers in the CD-ROM course. Demonstrates trials of a mode of self-assessment in tasks using annotated sample texts generated by other students. (VWL)

  11. Literature Review Guide1 A stand alone literature review should include the following

    E-print Network

    Van de Ven, James D.

    Literature Review Guide1 A stand alone literature review should include the following: (a) A cover on this problem and their limitations. (d) A critical literature review (limited to 2000 words) which summarizes research endeavor to extend the field beyond the state-of-art evident in the literature review

  12. Teaching Classroom Management: A Stand-Alone Necessity for Preparing New Teachers.

    ERIC Educational Resources Information Center

    Landau, Barbara McEwan

    This paper presents several arguments for including a stand-alone course on classroom management in every teacher preparation program. Some teacher preparation programs do not offer any course in classroom management, while others offer classroom management as an elective or as a topic embedded into another course. In the latter situation, the…

  13. Stand-alone minimally invasive lateral lumbar interbody fusion: multicenter clinical outcomes.

    PubMed

    Ahmadian, Amir; Bach, Konrad; Bolinger, Bryan; Malham, Gregory M; Okonkwo, David O; Kanter, Adam S; Uribe, Juan S

    2015-04-01

    Stand-alone minimally invasive lateral transpsoas interbody fusion (MIS-LIF), without posterior instrumentation, is feasible because the technique does not necessitate the disruption of the stabilizing elements. The objectives of this study are to evaluate the efficacy and clinical outcomes of patients who underwent stand-alone lateral interbody fusion. A multicenter chart review was conducted to identify patients who underwent stand-alone MIS-LIF between 2008 and 2012. Patients were classified by spinal pathology (degenerative disc disease [DDD], spondylolisthesis [SL] and adult degenerative scoliosis [ADS]). Routine clinical follow-up was scheduled at 3, 6, and12 months. Outcome measures included hospital length of stay, fusion rates, neurologic complications, integrity of construct and clinical outcome questionnaires (Visual Analog Scale [VAS] and Oswestry Disability Index [ODI]). A total of 59 patients met the inclusion criteria. The average age was 60 years (range 31-86 years). Spinal pathologies treated were DDD in 37 (63%), SL in four (7%) and ADS in 18 (30%) patients. Fusion rate was 93% of patients (95% of levels) at 12 months. Two patients required re-operation. Mean hospital stay and follow-up were 3.3days (range 1-10) and 14.6 months, respectively. The mean preoperative VAS and ODI were 69.1 and 51.8, respectively. VAS improved to 37.8 (p<0.0005). ODI improved to 31.8 (p<0.0005). Seventy percent of patients had grade 0 subsidence while 30% had grade I and grade II subsidence. Stand-alone MIS-LIF is viable option in a carefully selected patient population for both single and multilevel disease and shows significant improvement in health related quality of life. PMID:25684343

  14. Honeywell/Capstone Parallel Stand-alone Tests Honeywell/Capstone Parallel Tests

    E-print Network

    Appendix H Honeywell/Capstone Parallel Stand-alone Tests 6/20/2001 #12;Honeywell/Capstone Parallel-connect MTG #12;Capstone/Capstone Parallel Tests 6/20/2001 -10,000 0 10,000 20,000 30,000 40,000 50,000 60 and Shaft Speed #12;Honeywell/Capstone Parallel Tests 6/20/2001 -10,000 0 10,000 20,000 30,000 40,000 50

  15. TS Fuzzy Maximum Power Point Tracking Control of Solar Power Generation Systems

    Microsoft Academic Search

    Chian-Song Chiu

    2010-01-01

    This paper presents maximum power point tracking (MPPT) control for stand-alone solar power generation systems via the Takagi-Sugeno (T-S) fuzzy-model-based approach. In detail, we consider a dc\\/dc buck converter to regulate the output power of the photovoltaic panel array. First, the system is represented by the T-S fuzzy model. Next, in order to reduce the number of measured signals, a

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

    NASA Technical Reports Server (NTRS)

    Tomlinson, Bill

    1989-01-01

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

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

    Microsoft Academic Search

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

    2008-01-01

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

  18. Quick and reliable technology for fabrication of stand-alone BSCCO mesas

    NASA Astrophysics Data System (ADS)

    Vopilkin, E. A.; Chiginev, A. V.; Revin, L. S.; Tropanova, A. N.; Shuleshova, I. Yu; Okhapkin, A. I.; Shovkun, A. D.; Kulakov, A. B.; Pankratov, A. L.

    2015-04-01

    The technology of wet etching allowing fabrication of stand-alone BSCCO mesa structures was proposed. The produced mesas can be made much thicker than ones usually being studied. The time required for the fabrication is much smaller in comparison with the standard method of ion milling. The process used is controllable which provides acceptable precision of mesa fabrication. The IV characteristics of the sample showing Josephson nature were obtained. The qualitative comparison with characteristics of similar structures fabricated by other groups was carried out.

  19. Continuous monitoring bed-level dynamics on an intertidal flat: introducing novel stand-alone high-resolution SED-sensors

    NASA Astrophysics Data System (ADS)

    Hu, Zhan; Lenting, Walther; van der Wal, Daphne; Bouma, Tjeerd

    2015-04-01

    Tidal flat morphology is continuously shaped by hydrodynamic force, resulting in highly dynamic bed elevations. The knowledge of short-term bed-level changes is important both for understanding sediment transport processes as well as for assessing critical ecological processes such as e.g. vegetation recruitment chances on tidal flats. Due to the labour involved, manual discontinuous measurements lack the ability to continuously monitor bed-elevation changes. Existing methods for automated continuous monitoring of bed-level changes lack vertical accuracy (e.g., Photo-Electronic Erosion Pin sensor and resistive rod) or limited in spatial application by using expensive technology (e.g., acoustic bed level sensors). A method provides sufficient accuracy with a reasonable cost is needed. In light of this, a high-accuracy sensor (2 mm) for continuously measuring short-term Surface-Elevation Dynamics (SED-sensor) was developed. This SED-sensor makes use of photovoltaic cells and operates stand-alone using internal power supply and data logging system. The unit cost and the labour in deployments is therefore reduced, which facilitates monitoring with a number of units. In this study, the performance of a group of SED-sensors is tested against data obtained with precise manual measurements using traditional Sediment Erosion Bars (SEB). An excellent agreement between the two methods was obtained, indicating the accuracy and precision of the SED-sensors. Furthermore, to demonstrate how the SED-sensors can be used for measuring short-term bed-level dynamics, two SED-sensors were deployed for 1 month at two sites with contrasting wave exposure conditions. Daily bed-level changes were obtained including a severe storm erosion event. The difference in observed bed-level dynamics at both sites was statistically explained by their different hydrodynamic conditions. Thus, the stand-alone SED-sensor can be applied to monitor sediment surface dynamics with high vertical and temporal resolutions, which provides opportunities to pinpoint morphological responses to various forces in a number of environments (e.g. tidal flats, beaches, rivers and dunes).

  20. Fraction collection in capillary electrophoresis for various stand-alone mass spectrometers.

    PubMed

    Helmja, Kati; Borissova, Maria; Knjazeva, Tatjana; Jaanus, Martin; Muinasmaa, Urmas; Kaljurand, Mihkel; Vaher, Merike

    2009-04-24

    A procedure for collecting fractions during capillary electrophoresis for their analysis using various stand-alone instruments is described. The results of a systematic study of the optimization and application of capillary electrophoresis (CE) in conjunction with a reverse-phase high-performance liquid chromatography electrospray ionization quadrupole time of flight-tandem mass spectrometry (RP-HPLC-ESI-Q-TOF-MS/MS) and inductively-coupled mass spectrometry (ICP-MS) to the analysis of the seed extract of the Japanese Pagoda Tree (Sophora japonica) are presented. The off-line coupling of CE to the matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) for the proteins mixture was applied. The cathode end of the capillary was placed inside a stainless steel needle using a coaxial liquid-sheath-flow configuration. The optimization of experimental parameters resulted in an efficient methodology for MS analysis of fractions. Several components contained in the extract of S. japonica were identified, some not previously known. It was demonstrated that low sensitivity, which is a real problem in off-line CE-MS analysis, could be tolerated because of a more flexible optimization of the CE separation conditions and the choice of independent stand-alone instruments for analysis of separated fractions. The estimated limit of detection for CE-RP-HPLC-ESI-Q-TOF-MS was 50 microM of polyphenols and for CE-ICP-MS, 1-100 microg/l. PMID:19147148

  1. Generation matching and economic evaluation of household wind\\/PV hybrid power system

    Microsoft Academic Search

    Fengge Zhang; Hao Li; Yuxin Wang

    2009-01-01

    Renewable energy has stronger relationship with human development than ever. According to extensive studies on existed stand alone wind and photovoltaic (PV) hybrid power system, a novel method of optimum sizing was presented to obtain proper combination of wind and solar generation and effectively analyzed economic performance. Annual total cost model was proposed and genetic algorithm (GA) was used to

  2. CEPH accreditation of stand-alone baccalaureate programs: a preliminary mapping exercise.

    PubMed

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

    2015-01-01

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

  3. Photoinduced postsynthetic polymerization of a metal-organic framework toward a flexible stand-alone membrane.

    PubMed

    Zhang, Yuanyuan; Feng, Xiao; Li, Haiwei; Chen, Yifa; Zhao, Jingshu; Wang, Shan; Wang, Lu; Wang, Bo

    2015-03-27

    Metal-organic frameworks (MOFs) are a promising class of nanoporous polymeric materials. However, the processing of such fragile crystalline powders into desired shapes for further applications is often difficult. A photoinduced postsynthetic polymerization (PSP) strategy was now employed to covalently link MOF crystals by flexible polymer chains, thus endowing the MOF powders with processability and flexibility. Nanosized UiO-66-NH2 was first functionalized with polymerizable functional groups, and its subsequent copolymerization with monomers was easily induced by UV light under solvent-free and mild conditions. Because of the improved interaction between MOF particles and polymer chains, the resulting stand-alone and elastic MOF-based PSP-derived membranes possess crack-free and uniform structures and outstanding separation capabilities for Cr(VI) ions from water. PMID:25736697

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

    PubMed Central

    2013-01-01

    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

  5. HT / LT SERIES SMALL BATCH FURNACE SYSTEMS

    E-print Network

    , auto loading as an option, MFC gas systems, variable incoming power, various models to accommodate both in operation. Though cost effective as a stand alone heat source, today's desire for DDC operation, MFC gas

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

    PubMed

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

    2013-07-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

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

    PubMed Central

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

    2012-01-01

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

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

    ERIC Educational Resources Information Center

    Massachusetts State Water Resources Authority, Boston.

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

  10. 77 FR 14006 - Proposed Development of the Alaska Stand Alone Gas Pipeline Project (ASAP), From the North Slope...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-08

    ...Development of the Alaska Stand Alone Gas Pipeline Project (ASAP), From the North Slope to South Central Alaska, Draft Environmental...Engineers (Corps) published its Notice of Availability for the ASAP DEIS for public comment. In that notice, the Corps stated...

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

    NASA Technical Reports Server (NTRS)

    Bifano, W. J.

    1981-01-01

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

  12. Biomechanical comparison of two different concepts for stand alone anterior lumbar interbody fusion.

    PubMed

    Schleicher, Philipp; Gerlach, R; Schär, B; Cain, C M J; Achatz, W; Pflugmacher, R; Haas, N P; Kandziora, F

    2008-12-01

    Segmental instability in degenerative disc disease is often treated with anterior lumbar interbody fusion (ALIF). Current techniques require an additional posterior approach to achieve sufficient stability. The test device is an implant which consists of a PEEK-body and an integrated anterior titanium plate hosting four diverging locking screws. The test device avoids posterior fixation by enhancing stability via the locking screws. The test device was compared to an already established stand alone interbody implant in a human cadaveric three-dimensional stiffness test. In the biomechanical test, the L4/5 motion segment of 16 human cadaveric lumbar spines were isolated and divided into two test groups. Tests were performed in flexion, extension, right and left lateral bending, right and left axial rotation. Each specimen was tested in native state first, then a discectomy was performed and either of the test implants was applied. Finite element analysis (FE) was also performed to investigate load and stress distribution within the implant in several loading conditions. The FE models simulated two load cases. These were flexion and extension with a moment of 5 Nm. The biomechanical testing revealed a greater stiffness in lateral bending for the SynFix-LR compared to the established implant. Both implants showed a significantly higher stiffness in all loading directions compared to the native segment. In flexion loading, the PEEK component takes on most of the load, whereas the majority of the extension load is put on the screws and the screw-plate junction. Clinical investigation of the test device seems reasonable based on the good results reported here. PMID:18841399

  13. Biomechanical comparison of two different concepts for stand alone anterior lumbar interbody fusion

    PubMed Central

    Gerlach, R.; Schär, B.; Cain, C. M. J.; Achatz, W.; Pflugmacher, R.; Haas, N. P.; Kandziora, F.

    2008-01-01

    Segmental instability in degenerative disc disease is often treated with anterior lumbar interbody fusion (ALIF). Current techniques require an additional posterior approach to achieve sufficient stability. The test device is an implant which consists of a PEEK-body and an integrated anterior titanium plate hosting four diverging locking screws. The test device avoids posterior fixation by enhancing stability via the locking screws. The test device was compared to an already established stand alone interbody implant in a human cadaveric three-dimensional stiffness test. In the biomechanical test, the L4/5 motion segment of 16 human cadaveric lumbar spines were isolated and divided into two test groups. Tests were performed in flexion, extension, right and left lateral bending, right and left axial rotation. Each specimen was tested in native state first, then a discectomy was performed and either of the test implants was applied. Finite element analysis (FE) was also performed to investigate load and stress distribution within the implant in several loading conditions. The FE models simulated two load cases. These were flexion and extension with a moment of 5 Nm. The biomechanical testing revealed a greater stiffness in lateral bending for the SynFix-LR™ compared to the established implant. Both implants showed a significantly higher stiffness in all loading directions compared to the native segment. In flexion loading, the PEEK component takes on most of the load, whereas the majority of the extension load is put on the screws and the screw–plate junction. Clinical investigation of the test device seems reasonable based on the good results reported here. PMID:18841399

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

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

    DOEpatents

    Tam, S.W.

    1997-02-25

    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.

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

    DOEpatents

    Tam, S.W.

    1998-06-16

    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.

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

    Microsoft Academic Search

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

    2008-01-01

    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.

  18. Stirling Machines for High-Efficiency and Ecologically Clean Stand-Alone Energy Supply Systems

    Microsoft Academic Search

    N. G. Kirillov

    2000-01-01

    Gas regenerative machines operating on forward and reverse Stirling cycles (Stirling machines) [1] are the most promising ecologically clean energy converters which meet the requirements of energy generation with minimum use of material resources. Structurally, Stirling machines contain in a single unit a compressor, an expander, and heat-exchanging devices (heater or condenser, regenerator, and refrigerator). The working medium used is

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

    Microsoft Academic Search

    G. Tina; S. Gagliano; S. Raiti

    2006-01-01

    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

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

    Microsoft Academic Search

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

    2008-01-01

    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

  1. Clinical outcome of stand-alone ALIF compared to posterior instrumentation for degenerative disc disease: A pilot study and a literature review.

    PubMed

    Udby, Peter M; Bech-Azeddine, Rachid

    2015-06-01

    The objective of the article was to: a) present results from a case cohort pilot study comparing stand-alone ALIF and TLIF and, b) review the literature on studies comparing the clinical outcome of stand-alone ALIF with posterior instrumentation including TLIF or PLIF, in patients with disabling low back pain resulting from degenerative disc disease. ALIF surgery has previously been linked with certain high risk complications and unfavorable long term fusion results. Newer studies suggest that stand-alone ALIF can possibly be advantageous compared to other types of posterior instrumented interbody fusion for a selected group of DDD patients. The methods and material consisted of a cohort pilot study of patients, with DDD treated with stand-alone ALIF or TLIF followed by a literature review conducted through a comprehensive PubMed database search of the English literature. Studies comparing stand-alone ALIF with posterior instrumented interbody fusion were selected and reviewed. Results from the pilot study, n = 21, showed a reduced perioperative blood loss, shorter operative time and a trend towards better pain reduction and decreased use of opioid analgesics in patients undergoing stand-alone ALIF compared to posterior instrumented fusion with TLIF. The literature review included three studies, n = 630. All three studies were retrospective cohort studies. The average patient follow-up was 2-years but with heterogeneous selected outcomes. Two of three articles documented significant advantages when using stand-alone ALIF on outcomes such as ODI, VAS, surgical time, blood loss and patient satisfaction. No study found stand-alone ALIF inferior in chosen outcomes including fusion. In conclusion the pilot study and the literature review, finds similar clinical outcomes and fusion rates after stand-alone ALIF and posterior interbody fusion. Stand-alone ALIF was associated with a shorter duration of surgery, less perioperative blood loss and a faster improvement post-operatively. Therefore stand-alone ALIF is a viable and important surgical option, which could be considered first choice as surgical treatment. PMID:25855474

  2. Improved Design and Analysis of Self-Powered Synchronized Switch Interface Circuit for Piezoelectric Energy Harvesting Systems

    Microsoft Academic Search

    Junrui Liang; Wei-Hsin Liao

    2012-01-01

    In piezoelectric energy harvesting (PEH), with the use of the technique named synchronized switch harvesting on inductor (SSHI), the harvesting efficiency can be greatly enhanced. Furthermore, the introduction of its self-powered feature makes this technique more applicable for stand-alone systems. In this paper, a modified circuit and an improved analysis for the self- powered SSHI (SP-SSHI) are proposed. With the

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

    SciTech Connect

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

    1995-01-01

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

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

    E-print Network

    induction machine as generator. This generator is connected directly to the grid. It therefore requires machines etc.) as soon as electrical power is introduced. The conventional way of introducing electrical

  5. INTERNATIONAL ENERGY AGENCY TASK II DATABASE ON PHOTOVOLTAIC POWER SYSTEMS: STATISTICAL AND ANALYTICAL EVALUATION OF PV OPERATIONAL DATA

    Microsoft Academic Search

    U. Jahn; M. Niemann; G. Blaesser; R. Dahl; S. Castello; L. Clavadetscher; D. Faiman; D. Mayer; K. van Otterdijk; J. Sachau; K. Sakuta; M. Yamaguchi; M. Zoglauer

    As a part of the International Energy Agency (IEA) Photovoltaic Power Systems Co-operative Programme (PVPS), Task II, the above mentioned participants are collecting and analysing operational data of photovoltaic plants in various system techniques (grid-connected, stand-alone, hybrid) located all over the world. The objective of this joint project is to provide PV experts and other target groups with suitable information

  6. An explosively driven high-power microwave pulsed power system

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

  7. Power conditioning: The link between solar conversion and consumer

    Microsoft Academic Search

    S. Heier; W. Kleinkauf; J. Sachau

    1994-01-01

    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

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

    Microsoft Academic Search

    Roberto Cárdenas; Rubén Peña; Greg Asher; Jon Clare

    2001-01-01

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

  9. Automatic management of energy flows of a stand-alone renewable energy with support of hydrogen

    Microsoft Academic Search

    M. Calderón; A. J. Calderón; A. Ramiro; J. F. González

    This work deals with the design and built of an automation system for controlling the electric energy flows that take place at the continuous current bus (DC Bus) of a wind-solar system with support of hydrogen. The automation system is based on a Siemens PLC s7_313C_2DP. This PLC has been equipped with a Micro Memory Card (MMC) of 2 MB

  10. Automatic management of energy flows of a stand-alone renewable energy supply with hydrogen support

    Microsoft Academic Search

    M. Calderón; A. J. Calderón; A. Ramiro; J. F. González

    2010-01-01

    This work deals with the design and construction of an automation system for controlling the electric energy flows that take place at the continuous current bus (DC Bus) of a wind–solar system with hydrogen support. The automation system is based on a Siemens PLC s7_313C_2DP. This PLC was equipped with a Micro Memory Card (MMC) of 2MB in order to

  11. Optimal Variable Structure Self Regulating PSO-Controller for Stand-Alone Wave Energy Conversion Scheme

    Microsoft Academic Search

    Adel M. Sharaf; Adel A. A. El-Gammal

    2010-01-01

    The paper presents a novel stabilization controller scheme system for a Wave Energy Converter (WEC). The proposed controller of WEC-Battery renewable energy system is based on Multi Objective Particle Swarm Optimization MOPSO technique. The optimization algorithm is implemented to control a novel low cost dynamic AC side filter\\/capacitor compensation scheme. The novel Dynamic Modulated Filter Capacitor Compensation scheme (MPFC) serves

  12. CRionScan: A stand-alone real time controller designed to perform ion beam imaging, dose controlled irradiation and proton beam writing

    NASA Astrophysics Data System (ADS)

    Daudin, L.; Barberet, Ph.; Serani, L.; Moretto, Ph.

    2013-07-01

    High resolution ion microbeams, usually used to perform elemental mapping, low dose targeted irradiation or ion beam lithography needs a very flexible beam control system. For this purpose, we have developed a dedicated system (called “CRionScan”), on the AIFIRA facility (Applications Interdisciplinaires des Faisceaux d'Ions en Région Aquitaine). It consists of a stand-alone real-time scanning and imaging instrument based on a Compact Reconfigurable Input/Output (Compact RIO) device from National Instruments™. It is based on a real-time controller, a Field Programmable Gate Array (FPGA), input/output modules and Ethernet connectivity. We have implemented a fast and deterministic beam scanning system interfaced with our commercial data acquisition system without any hardware development. CRionScan is built under LabVIEW™ and has been used on AIFIRA's nanobeam line since 2009 (Barberet et al., 2009, 2011) [1,2]. A Graphical User Interface (GUI) embedded in the Compact RIO as a web page is used to control the scanning parameters. In addition, a fast electrostatic beam blanking trigger has been included in the FPGA and high speed counters (15 MHz) have been implemented to perform dose controlled irradiation and on-line images on the GUI. Analog to Digital converters are used for the beam current measurement and in the near future for secondary electrons imaging. Other functionalities have been integrated in this controller like LED lighting using Pulse Width Modulation and a “NIM Wilkinson ADC” data acquisition.

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

    NASA Astrophysics Data System (ADS)

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

    2010-08-01

    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 a Seebeck coefficient in the range of 90-250 µV K-1 and an in-plane electrical resistivity in the range of 7-17 µ? m. The measurements also showed TE figures-of-merit, ZT, at room temperatures (T = 300 K) of 0.97 and 0.56, for thin films of Bi2Te3 and Sb2Te3, respectively (equivalent to a power factor, PF, of 4.87 mW K-2 m-1 and 2.81 mW K-2 m-1). The solid-state battery is based on thin films of: an anode of tin dioxide (SnO2), an electrolyte of lithium phosphorus oxynitride (LixPOyNz, known as LiPON) and a cathode of lithium cobaltate (LiCoO2, known as LiCO), which were deposited using the reactive RF (radio-frequency) sputtering. The deposition and characterization results of these thin-films layers are also reported in this paper.

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

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

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

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

    SciTech Connect

    Hoffman, Michael G.; Russo, Bryan J.

    2011-06-23

    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.

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

    PubMed

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

    2011-06-15

    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

  17. EXPANDABLE HYBRID SYSTEMS FOR MULTI-USER MINI-GRIDS Michel Vandenbergh1

    E-print Network

    Paris-Sud XI, Université de

    represents a high potential market for hybrid power systems. Many stand-alone diesel units are powering mini by a high power penetration level of at least one non-dispatchable RE source. In this power range, available power generators. In order to achieve this goal, new energy management and demand management strategies

  18. Why Kirk Stands Alone.

    ERIC Educational Resources Information Center

    Chalfant, James C.

    1998-01-01

    The career of psychologist Samuel Kirk, the "father" of learning disabilities (LD), is reviewed. Noted are his professional career, his dedication to scholarship and inquiry, his continued involvement with people with LD, his ability to integrate knowledge from different disciplines, his creative use of research, his preparation of other leaders,…

  19. Standing Alone in Judgment

    ERIC Educational Resources Information Center

    Freado, Mark D.; Bath, Howard I.

    2014-01-01

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

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

    PubMed Central

    Barker, Jonathan

    2013-01-01

    Human protein kinases play fundamental roles mediating the majority of signal transduction pathways in eukaryotic cells as well as a multitude of other processes involved in metabolism, cell-cycle regulation, cellular shape, motility, differentiation and apoptosis. The human protein kinome contains 518 members. Most studies that focus on the human kinome require, at some point, the visualization of large amounts of data. The visualization of such data within the framework of a phylogenetic tree may help identify key relationships between different protein kinases in view of their evolutionary distance and the information used to annotate the kinome tree. For example, studies that focus on the promiscuity of kinase inhibitors can benefit from the annotations to depict binding affinities across kinase groups. Images involving the mapping of information into the kinome tree are common. However, producing such figures manually can be a long arduous process prone to errors. To circumvent this issue, we have developed a web-based tool called Kinome Render (KR) that produces customized annotations on the human kinome tree. KR allows the creation and automatic overlay of customizable text or shape-based annotations of different sizes and colors on the human kinome tree. The web interface can be accessed at: http://bcb.med.usherbrooke.ca/kinomerender. A stand-alone version is also available and can be run locally. PMID:23940838

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  3. Adult Degenerative Scoliosis with Spinal Stenosis Treated with Stand-Alone Cage via an Extreme Lateral Transpsoas Approach; a Case Report and Literature Review

    PubMed Central

    von Keudell, Arvind; Alimi, Marjan; Gebhard, Harry; Härtl, Roger

    2015-01-01

    We report the case of a 73-year-old female with severe degenerative scoliosis and back and leg pain that was successfully treated with stand- alone cages via an extreme lateral transpsoas approach. This patient had declined open surgery and instrumentation due to her advanced age concerns about potential side effects. PMID:26110180

  4. Subtask 3.12 - Small Power Systems

    SciTech Connect

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

    1997-08-01

    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.

  5. Final Technical Report: Hawaii Hydrogen Center for Development and Deployment of Distributed Energy Systems

    Microsoft Academic Search

    Rocheleau; Richard E

    2008-01-01

    Hydrogen power park experiments in Hawaii produced real-world data on the performance of commercialized electrochemical components and power systems integrating renewable and hydrogen technologies. By analyzing the different losses associated with the various equipment items involved, this work identifies the different improvements necessary to increase the viability of these technologies for commercial deployment. The stand-alone power system installed at Kahua

  6. Performance characteristics of solar-photovoltaic flywheel-storage systems

    Microsoft Academic Search

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

    1981-01-01

    A solar photovoltaic energy flywheel storage and conversion system for residential applications was 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

  7. The simulated dynamical photovoltaic array systems

    Microsoft Academic Search

    Guangyu Liu; Sing Kiong Nguang; Yuan Ren

    2010-01-01

    Temporal performance of a generic stand-alone photovoltaic (PV) array system was simulated numerically under the influence of the environmental variables: irradiation and temperature and a variable external power demand. The temporally and spatially distributed irradiation and temperature were integrated to the solution of the nonlinear PV array model. The PV power output that was regulated by DC-DC converter with or

  8. Long-term outcome after adjacent two-level anterior cervical discectomy and fusion using stand-alone plasmaphore-covered titanium cages.

    PubMed

    Marbacher, Serge; Hidalgo-Staub, Teresa; Kienzler, Jenny; Wüergler-Hauri, Carola; Landolt, Hans; Fandino, Javier

    2015-05-01

    Background?Reports on long-term outcome of stand-alone contiguous two-level anterior cervical discectomy and fusion (ACDF) using stand-alone Plasmaphore-coated titanium cages (PCTCs) are rare, and data on follow-ups?>?3 years are missing. Objective?To evaluate the long-term outcome of adjacent two-level microsurgical ACDF using stand-alone PCTC. Patients/Material and Methods?A total of 33 consecutive patients presented with cervical degenerative disc disease (DDD) underwent contiguous two-level ACDF. Clinical long-term evaluation (mean: 61?±?14 months) included documentation of neurologic deficits (motor deficits, sensory deficits, reflex status, and gait disturbance), neck pain, and radicular pain. Functional outcome was measured using the Odom criteria, patient-perceived outcome, and evaluation of work status. Radiographs were evaluated to assess intervertebral disc height, subsidence, level of fusion, sagittal balance, and implant position. Results?Surgery was performed at levels C5-C6 and C6-C7 in 30 patients and at C4-C5 and C5-C6 in 3 (mean age: 50.1?±?7.7 years). Symptoms and neurologic deficits improved as follows: neurologic deficits (pre: 100%; post: 36%), radicular pain (pre: 85%; post: 15%), and neck pain (pre: 94%; post: 33%). Excellent and good functional and subjective outcome was noted in 75%. Cage subsidence was found to be more prominent in the lower (52%) than the upper (36%) mobile cervical segment. Two-level fusion was documented in most patients (n?=?29 [88%]). Kyphotic deformity occurred in two cases (n?=?2 [6%]). Conclusions?Stand-alone contiguous two-level ACDF using PCPT proved to be effective, yielding good long-term clinical and functional outcomes. The relatively high rate of subsidence did not affect the good clinical and functional long-term outcome. PMID:25072316

  9. A photovoltaic system with energy storage - Natural Bridges National Monument 100kW system

    Microsoft Academic Search

    F. J. Solman; H. J. Bullwinkel; J. D. Doucet; B. L. Brench

    1982-01-01

    A large, stand-alone photovoltaic power system with energy storage has been in operation for over 18 months at Natural Bridges National Monument in southeastern Utah. Operating results for the system are in substantial agreement with simulations done before construction. Measured data are now available for the battery performance over this period. The design considerations and how they were realized are

  10. Market assessment of photovoltaic power systems for agricultural applications in Nigeria

    SciTech Connect

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

    1981-10-01

    The results of a month-long study in Nigeria conducted in February 1981 are detailed. The study was aimed at assessing in the 1981 to 1986 market potential for stand-alone photovoltaic systems in agriculture. Information on technically and economically feasible applications, and assessments of business, government and financial climate for photovoltaic sales are provided. The study concluded that the market for stand-alone photovoltaic power systems will be large, the primary reasons being the availability of capital and the high premium placed on high reliability, low maintenance power systems. A market exists for such agricultural/rural applications as: micro-irrigation, veterinary units, grain grinding, dryers, produce coolers, ice makers, water/boreholes, and health, education and extension services. Other markets with high PV sales potential include: remote local government centers, public and private communication systems, TV battery chargers, domestic power supply and cathodic protection. The potential market for photovoltaics in the 1981 to 1986 time frame is estimated at about 1.9 to 4.7 MW. The major purchaser in the near-term would be the federal and state governments.

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

    ERIC Educational Resources Information Center

    Jacso, Peter

    1996-01-01

    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…

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed Central

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

    2014-01-01

    Background Degenerative disc disease is common and debilitating for many patients. If conservative extensive care fails, anterior lumbar interbody fusion has proven to be an alternative form of surgical management. The Stabilis Stand Alone Cage(SAC) was introduced as a method to obtain stability and fusion. The purpose of this study was to determine whether the Stabilis Stand Alone Cage (SAC) is comparable in safety and efficacy to the Bagby and Kuslich (BAK) device. Methods As part of a prospective, randomized, controlled FDA trial, 73 patients underwent anterior interbody fusion using either the SAC(56%) or the BAK device (44%). Results Background characteristics were similar between the two groups. There was no significant difference between the SAC and BAK groups in mean operative time or mean blood loss during surgery. Adverse event rates did not differ between the groups. Assessment of plain radiographs could not confirm solid fusion in 63% of control and 71% of study patients. Functional scores from Owestry and SF-36 improved in both groups by the two-year follow-up. There were no significant differences between the SAC and BAK patients with respect to outcome. Conclusions Both the Stabilis Stand Alone Cage and the BAK Cage provided satisfactory improvement in function and pain relief, despite less than expected radiographic fusion rates. The apparent incongruency between fusion rates and functional outcomes suggests that either radiographs underestimate the true incidence of fusion, or that patients are obtaining good pain relief and improved function despite a lower rate of fusion than previously reported. This was a Level III study. PMID:25694930

  14. Midterm energy forecasting system: stand-alone boiler model results. Service report SR\\/OA\\/79-04

    Microsoft Academic Search

    F. H. Murphy; J. H. Zalkind

    1979-01-01

    The Council on Wage and Price Stability requested an analysis of the incremental impacts of Fuel Use Act regulations as a function of the stringency of the economic test under which exemptions are granted. To carry out this analysis, EIA utilized both the stand-along Industrial Boiler Fuel Choice Model and a version of the same model integrated with the mid-term

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

    Microsoft Academic Search

    Pragya Nema; R. K. Nema; Saroj Rangnekar

    2010-01-01

    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

  16. A comparison of PV\\/electrolyser and photoelectrolytic technologies for use in solar to hydrogen energy storage systems

    Microsoft Academic Search

    G. J. Conibeer; B. S. Richards

    2007-01-01

    The approach of using hydrogen for an energy store to offset seasonal variations in solar energy is one very much at the periphery of current renewable energy system design. Nonetheless, its inherent advantages for long term storage in stand alone power systems warrant further detailed investigation. This paper provides a comparative overview of the very disparate technologies within two generic

  17. EXPANDABLE HYBRID SYSTEMS FOR MULTI-USER MINI-GRIDS

    Microsoft Academic Search

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

    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

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

    Microsoft Academic Search

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

    1996-01-01

    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

  19. Power system

    DOEpatents

    Hickam, Christopher Dale (Glasford, IL)

    2008-03-18

    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.

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

    Microsoft Academic Search

    Pradeep K. Katti; Mohan K. Khedkar

    2007-01-01

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

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

    Microsoft Academic Search

    Bogdan S. Borowy; Ziyad M. Salameh

    1994-01-01

    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

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

    Microsoft Academic Search

    T. S. Davies; N. Larsen

    1989-01-01

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

  3. Effects of ozone as a stand-alone and coagulation-aid treatment on the reduction of trihalomethanes precursors from high DOC and hardness water.

    PubMed

    Sadrnourmohamadi, Mehrnaz; Gorczyca, Beata

    2015-04-15

    This study investigates the effect of ozone as a stand-alone and coagulation aid on the removal of dissolved organic carbon (DOC) from the water with a high level of DOC (13.8 mgL(-1)) and calcium hardness (270 mgL(-1)) CaCO3. Natural water collected from the Assiniboine River (Manitoba, Canada) was used in this study. Effectiveness of ozone treatment was evaluated by measurement of DOC, DOC fractions, UV254, and trihalomethane formation potential (THMFP). Additionally, zeta potential and dissolved calcium concentration were measured to discern the mechanism of ozone reactions. Results indicated that 0.8 mg O3/mg DOC ozone stand-alone can cause up to 86% UV254 reduction and up to 27% DOC reduction. DOC fractionation results showed that ozone can change the composition of DOC in the water samples, converting the hydrophobic fractions into hydrophilic ones and resulting in the reduction of THMFP. Also, ozone caused a decrease in particle stability and dissolved calcium concentration. These simultaneous ozonation effects caused improved water flocculation and enhanced removal of DOC. This resulted in reduction of the coagulant dosage when ozone doses higher than 0.2 mg O3/mg DOC were applied prior to coagulation with ferric sulfate. Also, pre-ozonation-coagulation process achieved preferential THMFP removal for all of the ozone doses tested (0-0.8 mg O3/mg DOC), leading to a lower specific THMFP in pre-ozonated-coagulated waters than in the corresponding ozonated waters. PMID:25659964

  4. POWER SYSTEMS

    Microsoft Academic Search

    1962-01-01

    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

  5. Photovoltaic power without batteries for continuous cathodic protection

    Microsoft Academic Search

    W. W. Muehl Sr.

    1994-01-01

    The COASTSYSTA designed, installed, and started up on 20 Jan. 1990, a state-of-the-art stand alone photovoltaic powered impressed current cathodic protection system (PVCPSYS) not requiring any auxiliary\\/battery backup power for steel and iron submerged structures. The PVCPSYS installed on 775' of steel sheet piling of a Navy bulkhead is continuing to provide complete, continuous corrosion protection. This has been well

  6. Three-Dimensional Virtual Model of the Human Temporal Bone: A Stand-Alone, Downloadable Teaching Tool

    PubMed Central

    Wang, Haobing; Northrop, Clarinda; Burgess, Barbara; Liberman, M. Charles; Merchant, Saumil N.

    2007-01-01

    Objective To develop a three-dimensional virtual model of a human temporal bone based on serial histologic sections. Background The three-dimensional anatomy of the human temporal bone is complex, and learning it is a challenge for students in basic science and in clinical medicine. Methods Every fifth histologic section from a 14-year-old male was digitized and imported into a general purpose three-dimensional rendering and analysis software package called Amira (version 3.1). The sections were aligned, and anatomic structures of interest were segmented. Results The three-dimensional model is a surface rendering of these structures of interest, which currently includes the bone and air spaces of the temporal bone; the perilymph and endolymph spaces; the sensory epithelia of the cochlear and vestibular labyrinths; the ossicles and tympanic membrane; the middle ear muscles; the carotid artery; and the cochlear, vestibular, and facial nerves. For each structure, the surface transparency can be individually controlled, thereby revealing the three-dimensional relations between surface landmarks and underlying structures. The three-dimensional surface model can also be “sliced open” at any section and the appropriate raw histologic image superimposed on the cleavage plane. The image stack can also be resectioned in any arbitrary plane. Conclusion This model is a powerful teaching tool for learning the complex anatomy of the human temporal bone and for relating the two-dimensional morphology seen in a histologic section to the three-dimensional anatomy. The model can be downloaded from the Eaton-Peabody Laboratory web site, packaged within a cross-platform freeware three-dimensional viewer, which allows full rotation and transparency control. PMID:16791035

  7. Optimal dispatch strategy in remote hybrid power systems

    SciTech Connect

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

    1996-10-01

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

  8. Neural network identification of power system transfer functions

    SciTech Connect

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

    1996-03-01

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

  9. Design description of the Tangaye Village photovoltaic power system

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

  10. QmRLFS-finder: a model, web server and stand-alone tool for prediction and analysis of R-loop forming sequences.

    PubMed

    Jenjaroenpun, Piroon; Wongsurawat, Thidathip; Yenamandra, Surya Pavan; Kuznetsov, Vladimir A

    2015-07-01

    The possible formation of three-stranded RNA and DNA hybrid structures (R-loops) in thousands of functionally important guanine-rich genic and inter-genic regions could suggest their involvement in transcriptional regulation and even development of diseases. Here, we introduce the first freely available R-loop prediction program called Quantitative Model of R-loop Forming Sequence (RLFS) finder (QmRLFS-finder), which predicts RLFSs in nucleic acid sequences based on experimentally supported structural models of RLFSs. QmRLFS-finder operates via a web server or a stand-alone command line tool. This tool identifies and visualizes RLFS coordinates from any natural or artificial DNA or RNA input sequences and creates standards-compliant output files for further annotation and analysis. QmRLFS-finder demonstrates highly accurate predictions of the detected RLFSs, proposing new perspective to further discoveries in R-loop biology, biotechnology and molecular therapy. QmRLFS-finder is freely available at http://rloop.bii.a-star.edu.sg/?pg=qmrlfs-finder. PMID:25883153

  11. QmRLFS-finder: a model, web server and stand-alone tool for prediction and analysis of R-loop forming sequences

    PubMed Central

    Jenjaroenpun, Piroon; Wongsurawat, Thidathip; Yenamandra, Surya Pavan; Kuznetsov, Vladimir A.

    2015-01-01

    The possible formation of three-stranded RNA and DNA hybrid structures (R-loops) in thousands of functionally important guanine-rich genic and inter-genic regions could suggest their involvement in transcriptional regulation and even development of diseases. Here, we introduce the first freely available R-loop prediction program called Quantitative Model of R-loop Forming Sequence (RLFS) finder (QmRLFS-finder), which predicts RLFSs in nucleic acid sequences based on experimentally supported structural models of RLFSs. QmRLFS-finder operates via a web server or a stand-alone command line tool. This tool identifies and visualizes RLFS coordinates from any natural or artificial DNA or RNA input sequences and creates standards-compliant output files for further annotation and analysis. QmRLFS-finder demonstrates highly accurate predictions of the detected RLFSs, proposing new perspective to further discoveries in R-loop biology, biotechnology and molecular therapy. QmRLFS-finder is freely available at http://rloop.bii.a-star.edu.sg/?pg=qmrlfs-finder. PMID:25883153

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

    Microsoft Academic Search

    E. Barrera-Cardiel; N. Pastor-Gomez

    1999-01-01

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

  13. Market assessment of photovoltaic power systems for agricultural applications worldwide

    NASA Astrophysics Data System (ADS)

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

    1981-11-01

    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.

  14. Market assessment of photovoltaic power systems for agricultural applications worldwide

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

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

    Microsoft Academic Search

    Chunhua Liu; K. T. Chau; Xiaodong Zhang

    2010-01-01

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

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

    SciTech Connect

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

    2009-12-15

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

  17. OP 790 -Auto Install Separator Plate, Feed & Rundown (2) Bolts OP 790 is a "stand-alone" automatic station in the sense that, although a conveyor runs through it on which

    E-print Network

    Tilbury, Dawn

    OP 790 - Auto Install Separator Plate, Feed & Rundown (2) Bolts OP 790 is a "stand-alone" automatic the pallet, a bolt feeder, the tooling for selecting a separator plate from one of four stacks and placing separately. The station PLC controls the conveyor pallet stops, the station tooling, the bolt feeder

  18. Performance analysis of power management policies in wireless networks

    Microsoft Academic Search

    Rong Zheng; Jennifer C. Hou; Lui Sha

    2006-01-01

    Abstract It has long been recognized that energy conservation usually comes,at the cost of degraded performance such as longer delay and lower throughput in stand-alone systems and communication networks. However, there have been very few research efforts in quantifying such trade-offs. In this paper, we develop analytical models to characterize the relationships among energy, delay and throughput for different power

  19. Next generation of AC coupled Hybrid systems - 3 phase parallel operation of grid forming battery inverters

    Microsoft Academic Search

    A. Engler; C. Hardt; N. Bechtel; M. Rothert

    Summary: The AC-coupling of components for stand-alone PV-battery-diesel hybrid power systems and the distributed generation in renewable energy micro grids is a challenging task for the control technology. Today's systems mostly run in master\\/slave operation with one battery inverter or one genset as the grid master. Extendable distributed power supplies can be considerably improved by introducing multi-master control concepts for

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

    SciTech Connect

    Kern, G.

    1999-04-01

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

  1. Thermoelectric generators in photovoltaic hybrid systems

    Microsoft Academic Search

    R. Kugele; W. Roth; W. Schulz; A. Steinhuser

    1996-01-01

    The supply of distant electric devices that cannot be connected to the public electricity grid for reasons of cost, waiting time or due to the need of local flexibility has been a major problem. To date, the power supply of such stand-alone systems has been based mainly on battery-buffered fossil-fueled motor-generators. Apart from the consumption of limited fossil fuel reserves,

  2. Simulated Photovoltaic Array Systems under a Changing Environment for Temporal Performance

    Microsoft Academic Search

    Guangyu Liu; Yuan Ren; Sing Kiong Nguang

    2012-01-01

    Temporal performance of a generic stand-alone photovoltaic (PV) array system was simulated numerically through a dynamical modelling approach under the influence of some time-varying external variables: irradiation, temperature and power demand. The underlying approach of solving general nonlinear equations by a robust Newton method was fundamental and powerful. Temporally and spatially non-uniform irradiation and temperature were considered as inputs to

  3. Electrification with solar powered mini-grids, a case study for the island of Kythnos

    Microsoft Academic Search

    S. Tselepis

    2003-01-01

    A study was prepared regarding the viability and potential of electrifying remote houses and settlements with stand alone PV systems in remote areas. The financial and technical factors that affect the implementation of stand alone PV systems in the Greek islands, and particularly for the island of Kythnos, are presented. The patterns of energy consumption of the users electrified by

  4. Power system commonality study

    Microsoft Academic Search

    Franklin D. Littman

    1992-01-01

    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

  5. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    PubMed

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

    2014-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Coleman, Anthony S.

    2004-01-01

    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.

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

    Microsoft Academic Search

    Jeffrey E. Norman; David N. Ruzic

    1999-01-01

    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

  8. Power management system

    DOEpatents

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

    2007-10-02

    A method of managing power resources for an electrical system of a vehicle may include identifying enabled power sources from among a plurality of power sources in electrical communication with the electrical system and calculating a threshold power value for the enabled power sources. A total power load placed on the electrical system by one or more power consumers may be measured. If the total power load exceeds the threshold power value, then a determination may be made as to whether one or more additional power sources is available from among the plurality of power sources. At least one of the one or more additional power sources may be enabled, if available.

  9. 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

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

    2014-09-01

    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

  10. The design of alarm and control system for electric fire prevention based on MSP430F149

    Microsoft Academic Search

    Xinjian Xiang; Ming Li

    2010-01-01

    This paper introduces an electrical fire control system which is composed of stand-alone electrical fire detector and electrical fire monitoring equipment. The detector with fieldbus communication technologies uses MCU to realize the main route leakage protection for low-voltage 3-phase 4-wire system; at the same time, finish the measure, display and control of voltage, current, power, electricity, temperature and other parameters;

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

    Microsoft Academic Search

    Shuaifei Zhao; Linda Zou; Dennis Mulcahy

    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

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

    Microsoft Academic Search

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

    2009-01-01

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

  13. Grid connected or stand-alone real-time variable speed wind generator emulator associated to a flywheel energy storage system

    Microsoft Academic Search

    C. Saudemont; G. Cimuca; B. Robyns; M. M. Radulescu

    2005-01-01

    The level of penetration increase of dispersed generation in the electrical networks is a major scientific aim: to increase the possibility to participate in the ancillary services, to determine the influence zone according to the network connection point,...etc. The development of experimental test benches is necessary to validate theoretical studies. In this paper, we present a 3 kW test bench,

  14. A regional comparison of solar, heat pump, and solar-heat pump systems

    Microsoft Academic Search

    B. E. Manton; J. W. Mitchell

    1982-01-01

    A comparative study of the thermal and economic performance of the parallel and series solar heat pump systems, stand alone solar and stand alone heat pump systems for residential space and domestic hot water heating for the U.S. using FCHART 4.0 is presented. Results show that the parallel solar heat pump system yields the greatest energy savings in the south.

  15. Development of a muon radiographic imaging electronic board system for a stable solar power operation

    NASA Astrophysics Data System (ADS)

    Uchida, T.; Tanaka, H. K. M.; Tanaka, M.

    2010-02-01

    Cosmic-ray muon radiography is a method that is used to study the internal structure of volcanoes. We have developed a muon radiographic imaging board with a power consumption low enough to be powered by a small solar power system. The imaging board generates an angular distribution of the muons. Used for real-time reading, the method may facilitate the prediction of eruptions. For real-time observations, the Ethernet is employed, and the board works as a web server for a remote operation. The angular distribution can be obtained from a remote PC via a network using a standard web browser. We have collected and analyzed data obtained from a 3-day field study of cosmic-ray muons at a Satsuma-Iwojima volcano. The data provided a clear image of the mountain ridge as a cosmic-ray muon shadow. The measured performance of the system is sufficient for a stand-alone cosmic-ray muon radiography experiment.

  16. Radioisotope powered AMTEC systems

    Microsoft Academic Search

    Joseph F. Ivanenok; R. K. Sievers

    1994-01-01

    Alkali Metal Thermal to Electric Converter (AMTEC) systems are being developed for high performance spacecraft power systems, including small, General Purpose Heat Source (GPHS) powered systems. Several design concepts have been evaluated for the power range from 75 W to 1 kW. The specific power for these concepts has been found to be as high as 18-20 W\\/kg and 22

  17. Market assessment of photovoltaic power systems for agricultural applications in Morocco

    NASA Astrophysics Data System (ADS)

    Steingass, H.; Asmon, I.

    1981-09-01

    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.

  18. Market assessment of photovoltaic power systems for agricultural applications in Morocco

    NASA Technical Reports Server (NTRS)

    Steingass, H.; Asmon, I.

    1981-01-01

    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.

  19. Solar Powered Refrigeration System

    Microsoft Academic Search

    Michael K. Ewert; David J. Bergeron III

    2002-01-01

    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

  20. Solar powered desalination system

    E-print Network

    Mateo, Tiffany Alisa

    2011-01-01

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

  1. Electrolyser-based energy management: a means for optimising the exploitation of variable renewable-energy resources in stand-alone applications

    Microsoft Academic Search

    R. G. M Crockett; M Newborough; D. J Highgate

    1997-01-01

    Electrolyser-based energy management (EBM) offers a versatile means for optimising the process of harnessing energy supplies derived from variable and\\/or intermittent renewable resources, e.g. solar (photo-voltaic), wind, wave and tidal. In general, EBM systems consist of an electrolyser, water and gas (hydrogen and, optimally, oxygen) storage and management systems and a means of (re-) generating electricity, e.g. a fuel cell.

  2. Space station power system

    NASA Technical Reports Server (NTRS)

    Baraona, Cosmo R.

    1987-01-01

    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.

  3. 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

    Steffen, Dale A.; And Others

    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…

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

    SciTech Connect

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

    1980-01-01

    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.

  5. Buyer's Guide to Computer Based Instructional Systems.

    ERIC Educational Resources Information Center

    Fratini, Robert C.

    1981-01-01

    Examines the advantages and disadvantages of shared multiterminal computer based instruction (CBI) systems, dedicated multiterminal CBI systems, and stand-alone CBI systems. A series of questions guide consumers in matching a system's capabilities with an organization's needs. (MER)

  6. Radioisotope powered AMTEC systems

    NASA Astrophysics Data System (ADS)

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

    1994-11-01

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

  7. Radioisotope powered AMTEC systems

    SciTech Connect

    Ivanenok, J.F. III; Sievers, R.K. [Advanced Modular Power Systems, Inc, Ann Arbor, MI (United States)] [Advanced Modular Power Systems, Inc, Ann Arbor, MI (United States)

    1994-11-01

    Alkali metal thermal to electric converter (AMTEC) systems are being developed for high performance spacecraft power systems, including small, general purpose heat source (GPHS) powered systems. Several design concepts have been evaluated for the power range from 75 W to 1 kW. The specific power for these concepts has been found to be as high as 18-20 W/kg and 22 kW/m(exp 3). The projected area, including radiators, has been as low as 0.4 m(exp 2)/kW. AMTEC power systems are extremely attractive, relative to other current and projected power systems, because AMTEC offers high power density, low projected area, and low volume. Two AMTEC cell design types have been identified. A single-tube cell is already under development and a multitube cell design, to provide additional power system gains, has undergone proof-of-principle testing. Solar powered AMTEC (SAMTEC) systems are also being developed, and numerous terrestrial applications have been identified for which the same basic AMTEC cells being developed for radioisotope systems are also suitable. 35 refs.

  8. Crowd-powered systems

    E-print Network

    Bernstein, Michael Scott

    2012-01-01

    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 ...

  9. Power system disturbance patterns

    Microsoft Academic Search

    D. O. Koval

    1989-01-01

    The author presents some power system disturbance patterns that were obtained by continuously monitoring the power supply of a computer system over a period of two years. An examination of the undervoltage disturbance patterns over this two-year period revealed that the majority of disturbances occurred during normal working hours (8 am-5 pm). The characteristic patterns were different from year to

  10. Exhibits Enhanced by Stand-Alone Computers.

    ERIC Educational Resources Information Center

    Van Rennes, Eve C.

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

  11. Stand alone biofuel production from algae

    Microsoft Academic Search

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

    2011-01-01

    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

  12. A Stand-Alone Interactive Physics Showcase

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  13. Adaptive power system control

    SciTech Connect

    Manansala, E.C.

    1989-01-01

    This work presents a centralized control scheme applied to a power system. The scheme has adaptive characteristics which allow the controller to keep track of the changing power system operating point and to control nonlinear functions of state variables. Feedback to the controller is obtained from phasor measurements at chosen power system buses, generator field voltage measurements, and state estimators. Control effort is aimed at minimizing the oscillations and influencing the power system state trajectory through the control of linear and nonlinear functions of state variables during a power system disturbance. The main contributions of this dissertation are the simultaneous introduction and utilization of measurement based terms in the state and output equations in the derivation and implementation of the control law, the study of limits on controller performance as the state residual vector becomes very large, and the simulation of the performance of local state estimators to prove the need for faster phasor measurement systems. The test system is a hypothetical 39-Bus AC power system consisting of typical components which have been sufficiently modelled for the simulation of power system performance in a dynamic stability study.

  14. TROPIX Power System Architecture

    NASA Technical Reports Server (NTRS)

    Manner, David B.; Hickman, J. Mark

    1995-01-01

    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.

  15. BioRadioTransmitter: A Self-Powered Wireless Glucose-Sensing System

    PubMed Central

    Hanashi, Takuya; Yamazaki, Tomohiko; Tsugawa, Wakako; Ikebukuro, Kazunori; Sode, Koji

    2011-01-01

    Background Although an enzyme fuel cell can be utilized as a glucose sensor, the output power generated is too low to power a device such as a currently available transmitter and operating system, and an external power source is required for operating an enzyme-fuel-cell-based biosensing system. We proposed a novel biosensor that we named BioCapacitor, in which a capacitor serves as a transducer. In this study, we constructed a new BioCapacitor-based system with an added radio-transmitter circuit and a miniaturized enzyme fuel cell. Methods A miniaturized direct-electron-transfer-type compartmentless enzyme fuel cell was constructed with flavin adenine dinucleotide-dependent glucose dehydrogenase complex-based anode and a bilirubin-oxidase-based cathode. For construction of a BioRadioTransmitter wireless sensing system, a capacitor, an ultra-low-voltage charge-pump-integrated circuit, and Hartley oscillator circuit were connected to the miniaturized enzyme fuel cell. A radio-receiver circuit, comprising two field-effect transistors and a coil as an antenna, was used to amplify the signal generated from the biofuel cells. Results Radio wave signals generated by the BioRadioTransmitter were received, amplified, and converted from alternate to direct current by the radio receiver. When the capacitor discharges in the presence of glucose, the BioRadioTransmitter generates a radio wave, which is monitored by a radio receiver connected wirelessly to the sensing device. Magnitude of the radio wave transmission frequency change observed at the radio receiver was correlated to glucose concentration in the fuel cells. Conclusions We constructed a stand-alone, self-powered, wireless glucose-sensing system called a BioRadioTransmitter by using a radio transmitter in which the radio wave transmission frequency changes with the glucose concentration in the fuel cell. The BioRadioTransmitter is a significant advance toward construction of an implantable continuous glucose monitor. PMID:22027294

  16. Mission Benefits of Gridded Ion and Hall Thruster Hybrid Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Dankanich, John W.; Polsgrove, Tara

    2006-01-01

    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.

  17. Dynamic power systems for power generation

    NASA Astrophysics Data System (ADS)

    English, R. E.

    1984-04-01

    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.

  18. Power Systems Control Architecture

    SciTech Connect

    James Davidson

    2005-01-01

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

  19. TOPEX electrical power system

    Microsoft Academic Search

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

    1991-01-01

    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

  20. The power supply system for the DEPFET pixel detector at BELLE II

    NASA Astrophysics Data System (ADS)

    Rummel, Stefan; Depfet Collaboration

    2013-01-01

    The upgrade of the KEKB accelerator towards 8×1035 cm-2 s-1 poses several challenges for the BELLE II detector. Especially the innermost detector will be faced with a significant radiation of several MRad per year as well as a high hit density. To cope with this a silicon pixel detector will be used for the inner layers of the silicon tracker. The pixel detector (PXD) consists of two layers of DEPFET active pixel sensors. The DEPFET technology has an unique set of advantages like low power dissipation in the active area, flexible device size, radiation hardness and a thinning procedure allowing to adjust the thickness of the device over a wide range. The two layers close to the interaction point together with a low material budget will improve the IP resolution by a factor of 2 compared to the previous installed silicon detector. In addition silicon stand-alone pattern recognition will be possible together with the four layers of double sided strip detectors (DSSD) of the strip detector. The PXD detector system consists of the DEPFET modules with integrated readout chips, the data handling hybrid receiving the data and sending them to compute nodes performing an online pattern recognition. Moreover the power supply system provides the supply voltages for the DEPFET from a position outside of the detector. The power distribution is designed to provide low output impedance over all frequencies and transient response with appropriate overshoots. The PXD pose several challenges to the power distribution system—number of voltages, tight requirements on regulation and noise.

  1. AC power system breadboard

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  2. Solar Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  3. Wind Power Systems 1. Overview

    E-print Network

    Ding, Yu

    Wind Power Systems 1. Overview 2. Simulation model for wind farm operation 3. Research topics #12;Contents 1. Overview of wind power systems 1.1 Power systems 1.2 Renewable energy 1.3 Wind power systems 1.4 Wind power integration 1.5 Summary 2. Simulation model of wind farm operations 3. Research

  4. Lunar power systems

    NASA Astrophysics Data System (ADS)

    Criswell, D. R.; Waldron, R. D.; Aldrin, B.

    Small areas of the moon's east and west limb surfaces can be transformed into solar collectors and transmitters, furnishing microwave power beam receivers on the moonward side of the earth with large amounts of inexpensive electricity. The receiving antennas would be 6-15 times smaller in area than a terrestrial photovoltaic array of comparable power. The lunar environment is inherently suited to the construction and long term operation of thin film-based systems for the conversion of diffuse sunlight into electricity; lunar soil, moreover, can be readily processed into glasses, ceramics, and agglutinates. The conversion of a 10,000-sq km lunar surface area into power conversion systems would allow the earth to be supplied with more power than it currently consumes.

  5. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  6. Autonomous power system brassboard

    NASA Technical Reports Server (NTRS)

    Merolla, Anthony

    1992-01-01

    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.

  7. Autonomous power system brassboard

    NASA Astrophysics Data System (ADS)

    Merolla, Anthony

    1992-10-01

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

  8. Laser satellite power systems

    SciTech Connect

    Walbridge, E.W.

    1980-01-01

    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.

  9. Power line detection system

    DOEpatents

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

    1994-01-01

    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.

  10. NASA: Radioisotope Power Systems

    NSDL National Science Digital Library

    2012-10-30

    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.

  11. Existing power system

    SciTech Connect

    NONE

    1995-10-01

    This portion of the energy Vision 2020 draft report is a discussion of the existing power system of the Tennessee Valley Authority. A summary listing of hydro, fossil, nuclear generating facilities is included, with net capacity and age being given for each unit. Data on emissions from coal-fired plants is also given. A discussion of TVA`s transmission system, including interchanges with existing utilities, is also given.

  12. Automotive power steering system

    SciTech Connect

    VanGorder, D.H.; Wilson, K.R.

    1991-04-23

    This patent describes improvement in an automotive power steering system including a pump, a servo-valve, a steering assist fluid motor, a reservoir having a reservoir chamber therein, fluid ducts; a volume of hydraulic oil; a fluid level. The improvement comprises: means defining a fill port; a cover; means connect a gas accumulator.

  13. DC Power Distribution Systems 

    E-print Network

    Savage, P.

    2012-01-01

    Low capital cost and ample low-cost natural gas supplies will make natural gas-fired combustion turbine systems the power generation technology of choice over the next decade. Against the background of earlier use by electric utilities, this paper...

  14. Autonomously managed electrical power systems

    NASA Technical Reports Server (NTRS)

    Callis, Charles P.

    1986-01-01

    The electric power systems for future spacecraft such as the Space Station will necessarily be more sophisticated and will exhibit more nearly autonomous operation than earlier spacecraft. These new power systems will be more reliable and flexible than their predecessors offering greater utility to the users. Automation approaches implemented on various power system breadboards are investigated. These breadboards include the Hubble Space Telescope power system test bed, the Common Module Power Management and Distribution system breadboard, the Autonomusly Managed Power System (AMPS) breadboard, and the 20 kilohertz power system breadboard. Particular attention is given to the AMPS breadboard. Future plans for these breadboards including the employment of artificial intelligence techniques are addressed.

  15. High power connection system

    DOEpatents

    Schaefer, Christopher E. (Warren, OH); Beer, Robert C. (Noblesville, IN); McCall, Mark D. (Youngstown, OH)

    2000-01-01

    A high power connection system adapted for automotive environments which provides environmental and EMI shielding includes a female connector, a male connector, and a panel mount. The female connector includes a female connector base and a snap fitted female connector cover. The male connector includes a male connector base and a snap fitted male connector cover. The female connector base has at least one female power terminal cavity for seatably receiving a respective female power terminal. The male connector base has at least one male power terminal cavity for seatably receiving a respective male power terminal. The female connector is covered by a cover seal and a conductive shroud. A pair of lock arms protrude outward from the front end of the male connector base, pass through the panel mount and interface with a lever of a lever rotatably connected to the shroud to thereby mechanically assist mating of the male and female connectors. Safety terminals in the male and female connectors provide a last-to-connect-first-to-break connection with an HVIL circuit.

  16. Power systems facility

    NASA Technical Reports Server (NTRS)

    1989-01-01

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

  17. Existing power system

    SciTech Connect

    NONE

    1995-10-01

    This portion of the Energy Vision 2020 draft report is a description of TVA`s existing power system. The existing system provides 25,600 MWe of generating capacity in the summer-57% from coal-fired plants, 16% from hydro facilities, 13% from nuclear facilities, 8% from combustion turbines, and 6% from pumped-storage hydro facilities. Two nuclear units will be added in 1996, bringing the total installed capacity to 28,800 MWe. TVA also operates 16,000 miles of transmission lines to carry power from 42 generating sites to 750 wholesale delivery points. TVA also connects with 13 neighboring utilities at 57 different locations. In 1994, TVA generated 134 billion KWh of electricity, with 84% going to wholesalers and the balance going directly to industrial and federal customers. The revenue from these sales was $5.4 billion.

  18. Power conditioning unit for photovoltaic power systems

    NASA Astrophysics Data System (ADS)

    Beghin, G.; Nguyen Phuoc, V. T.

    Operational features and components of a power conditioning unit for interconnecting solar cell module powers with a utility grid are outlined. The two-stage unit first modifies the voltage to desired levels on an internal dc link, then inverts the current in 2 power transformers connected to a vector summation control to neutralize harmonic distortion up to the 11th harmonic. The system operates in parallel with the grid with extra inductors to absorb line-to-line voltage and phase differences, and permits peak power use from the PV array. Reactive power is gained internally, and a power system controller monitors voltages, frequencies, and currents. A booster preregulator adjusts the input voltage from the array to provide voltage regulation for the inverter, and can commutate 450 amps. A total harmonic distortion of less than 5 percent is claimed, with a rating of 5 kVA, 50/60 Hz, 3-phase, and 4-wire.

  19. 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.

  20. Development of a multiplane multispeed balancing system for turbine systems

    NASA Technical Reports Server (NTRS)

    Martin, M. R.

    1984-01-01

    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.

  1. Power control system and method

    DOEpatents

    Steigerwald, Robert Louis; Anderson, Todd Alan

    2006-11-07

    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.

  2. Power control system and method

    DOEpatents

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

    2008-02-19

    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.

  3. A regional comparison of solar, heat pump, and solar heat pump systems

    NASA Astrophysics Data System (ADS)

    Manton, B. E.; Mitchell, J. W.

    The thermal and economic performance of the parallel and series solar-heat pump systems, stand-alone solar and stand-alone heat pump systems for residential space and domestic hot water heating is being compared for the United States using FCHART 4.0. The results are useful for a regional assessment of the viability of the different systems, and for assessing policies that will encourage the implementation of the most energy efficient system.

  4. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  5. Power electronic devices for renewable power systems

    Microsoft Academic Search

    Rik W. De Doncker; Christian P. Dick; Florian Mura; Thomas Butschen

    2010-01-01

    In the past, overhead lines, cables, transformers and circuit breakers represented the core components of electric power systems. However, in light of a considerable and still increasing share of renewable energy sources in grids, a change in electricity infrastructure can be observed. Over the last decades advances in power semiconductor devices have paved the way for innovative equipment such as

  6. Lunar power systems

    NASA Technical Reports Server (NTRS)

    1986-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    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.

  8. TOPEX electrical power system

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  9. Power Systems Development Facility

    SciTech Connect

    None

    2003-07-01

    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.

  10. Modelling STATCOM into power systems

    Microsoft Academic Search

    H. F. Wang

    1999-01-01

    This paper establishes the linearized Phillips-Heffron model of a power system installed with a STATCOM (static synchronous compensator) and demonstrates the applications of the model in analysing the damping effect of the STATCOM and designing a STATCOM stabilizer to improve power system oscillation stability. Both cases of single-machine infinite-bus and multi-machine power systems are studied and an example power system

  11. Power systems analysis and planning

    SciTech Connect

    Not Available

    1983-01-01

    This book presents the basic principles, applications, future outlook, and problems facing the Arab world (e.g., interconnection among power systems and standardization) in the area of power system engineering. Contents, abridged: Fault analysis. Load flow analysis. Transient stability analysis. Network interconnections equivalents. Power system planning. Index.

  12. Automated Power Systems Management (APSM)

    NASA Technical Reports Server (NTRS)

    Bridgeforth, A. O.

    1981-01-01

    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.

  13. POWER SYSTEMS DEVELOPMENT FACILITY

    SciTech Connect

    Unknown

    2002-11-01

    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.

  14. Solar thermal power system

    DOEpatents

    Bennett, Charles L.

    2010-06-15

    A solar thermal power generator includes an inclined elongated boiler tube positioned in the focus of a solar concentrator for generating steam from water. The boiler tube is connected at one end to receive water from a pressure vessel as well as connected at an opposite end to return steam back to the vessel in a fluidic circuit arrangement that stores energy in the form of heated water in the pressure vessel. An expander, condenser, and reservoir are also connected in series to respectively produce work using the steam passed either directly (above a water line in the vessel) or indirectly (below a water line in the vessel) through the pressure vessel, condense the expanded steam, and collect the condensed water. The reservoir also supplies the collected water back to the pressure vessel at the end of a diurnal cycle when the vessel is sufficiently depressurized, so that the system is reset to repeat the cycle the following day. The circuital arrangement of the boiler tube and the pressure vessel operates to dampen flow instabilities in the boiler tube, damp out the effects of solar transients, and provide thermal energy storage which enables time shifting of power generation to better align with the higher demand for energy during peak energy usage periods.

  15. Solar-Powered Refrigeration System

    Microsoft Academic Search

    Michael K. Ewert; David J. Bergeron III

    2002-01-01

    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

  16. Satellite Power System (SPS)

    NASA Technical Reports Server (NTRS)

    Edler, H. G.

    1978-01-01

    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.

  17. Power conditioning: The link between solar conversion and consumer

    SciTech Connect

    Heier, S. [Universitaet Gesamthochschule Kassel (Germany); Kleinkauf, W. [Universitaet Gesamthochschule Kassel (Germany)]|[Institut fuer Solare Energieversorgungstechnik, Kassel (Germany); Sachau, J. [Institut fuer Solare Energieversorgungstechnik, Kassel (Germany)

    1994-12-31

    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 energies at a premium price, since remote supply of electricity is currently linked with higher cost. In order to reduce the cost and to improve availability, the scalability to any nominal power and the suitability to central and decentral applications is discussed on the system level. The basic variants of converter technology in conjunction with current concentration are explained and assessed in regard to PV application. For wind energy conversion, the interaction between mechano-electrical transformation, grid connection, and control concept are analysed. Grid- and consumer-specific measures for power conditioning are displayed and analyzed with regard to voltage variation and harmonics. Concepts that are successfully used in practice are presented, main causes of disturbances of operating plants are listed, and new trends are outlined. For stand-alone systems, a combination of synchronous machines and battery-coupled inverter is suitable for grid formation. With advanced control methods, the standard permissable tolerances of voltage, frequency and harmonics can be achieved. Modular unit-kit construction allows high reliability and simple installation, operation and low maintenance, and the expansion of the supply system according to increasing needs. 35 refs., 61 figs., 1 tab.

  18. Body powered thermoelectric systems

    E-print Network

    Settaluri, Krishna Tej

    2012-01-01

    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 ...

  19. Pluto Express power system architecture

    SciTech Connect

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

    1996-12-31

    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.

  20. Solar probe power systems concepts

    SciTech Connect

    Nesmith, B.J. (JPL, Pasadena, CA (United States))

    1992-01-01

    Some of the design options under consideration for providing on-board electric power for the Solar Probe Mission are discussed. Five spacecraft configurations were evaluated with slightly different power demands and volumetric constraints on the power system. This resulted in three different baseline power system designs to satisfy the five spacecraft configurations. These three current baseline power system designs use modified general-purpose heat source (GPHS) radioisotope thermoelectric generators (RTGs) similar to those launched on the Galileo and Ulysses spacecraft. The modular RTG currently under development and testing is a potential advanced alternative to the current baseline GPHS-RTG technology design. 8 refs.

  1. US electric power system reliability

    NASA Astrophysics Data System (ADS)

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

  2. Switching power pulse system

    DOEpatents

    Aaland, K.

    1983-08-09

    A switching system for delivering pulses of power from a source to a load using a storage capacitor charged through a rectifier, and maintained charged to a reference voltage level by a transistor switch and voltage comparator. A thyristor is triggered to discharge the storage capacitor through a saturable reactor and fractional turn saturable transformer having a secondary to primary turn ratio N of n:l/n = n[sup 2]. The saturable reactor functions as a soaker'' while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor charges, and then switches to a low impedance state to dump the charge of the storage capacitor into the load through the coupling capacitor. The transformer is comprised of a multilayer core having two secondary windings tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe for a linear particle accelerator and capacitance of a pulse forming network. To hold off discharge of the capacitance until it is fully charged, a saturable core is provided around the resistive beampipe to isolate the beampipe from the capacitance until it is fully charged. 5 figs.

  3. Power quality load management for large spacecraft electrical power systems

    NASA Technical Reports Server (NTRS)

    Lollar, Louis F.

    1988-01-01

    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.

  4. POWER SYSTEMS DEVELOPMENT FACILITY

    SciTech Connect

    Unknown

    2002-05-01

    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.

  5. The space station power system

    NASA Technical Reports Server (NTRS)

    Baraona, C. R.

    1986-01-01

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

  6. Space station electrical power system

    NASA Technical Reports Server (NTRS)

    Labus, Thomas L.; Cochran, Thomas H.

    1987-01-01

    The purpose of this paper is to describe the design of the Space Station Electrical Power System. This includes the Photovoltaic and Solar Dynamic Power Modules as well as the Power Management and Distribution System (PMAD). In addition, two programmatic options for developing the Electrical Power System will be presented. One approach is defined as the Enhanced Configuration and represents the results of the Phase B studies conducted by the NASA Lewis Research Center over the last two years. Another option, the Phased Program, represents a more measured approach to reaching about the same capability as the Enhanced Configuration.

  7. Switching power pulse system

    DOEpatents

    Aaland, Kristian (Livermore, CA)

    1983-01-01

    A switching system for delivering pulses of power from a source (10) to a load (20) using a storage capacitor (C3) charged through a rectifier (D1, D2), and maintained charged to a reference voltage level by a transistor switch (Q1) and voltage comparator (12). A thyristor (22) is triggered to discharge the storage capacitor through a saturable reactor (18) and fractional turn saturable transformer (16) having a secondary to primary turn ratio N of n:l/n=n.sup.2. The saturable reactor (18) functions as a "soaker" while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor (C4) charges, and then switches to a low impedance state to dump the charge of the storage capacitor (C3) into the load through the coupling capacitor (C4). The transformer is comprised of a multilayer core (26) having two secondary windings (28, 30) tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes (32, 34) for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe (40) for a linear particle accelerator and capacitance of a pulse forming network (42). To hold off discharge of the capacitance until it is fully charged, a saturable core (44) is provided around the resistive beampipe (40) to isolate the beampipe from the capacitance (42) until it is fully charged.

  8. The space station power system

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The requirements for electrical power by the proposed Space Station Freedom are discussed. The options currently under consideration are examined. The three power options are photovoltaic, solar dynamic, and a hybrid system. Advantages and disadvantages of each system are tabulated. Drawings and artist concepts of the Space Station configuration are provided.

  9. Nanosatellite Power System Considerations

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  10. Analysis methods for wind turbine control and electrical system dynamics

    NASA Technical Reports Server (NTRS)

    Hinrichsen, E. N.

    1995-01-01

    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.

  11. Analysis methods for wind turbine control and electrical system dynamics

    NASA Astrophysics Data System (ADS)

    Hinrichsen, E. N.

    1995-05-01

    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.

  12. Limits to power system growth

    SciTech Connect

    Slater, S.M.; Klein, A.C. (Department of Nuclear Engineering, Oregon State University, Corvallis, Oregon 97331 (United States)); Webb, B.J. (Umpqua Research, Inc., P.O. Box 791, Myrtle Creek, Oregon 97457 (United States)); Pauley, K.A. (Battelle Pacific Northwest Laboratory, P.O. Box 999, Richland, Washington 99352 (United States))

    1993-01-15

    In the design of space nuclear power systems a variety of conversion techniques may be used, each with its own advantages and disadvantages. A study was performed which analyzed over 120 proposed system designs. The designs were compared to identify the optimum conversion system as a function of power level and find limits to specific mass (kg/kWe) for each power cycle. Furthermore, the component masses were studied to determine which component of the overall design contributes the most to total system mass over a variety of power levels. The results can provide a focus for future research efforts by selecting the best conversion technology for the desired power range, and optimizing the system component which contributes most to the total mass.

  13. Thruster models for NEP system analysis

    NASA Technical Reports Server (NTRS)

    Gilland, Jim

    1993-01-01

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

  14. Electrical power systems for Mars

    NASA Astrophysics Data System (ADS)

    Giudici, Robert J.

    1986-05-01

    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.

  15. Current directions in photovoltaic power conditioner development using smart power/power integrated circuit technologies

    SciTech Connect

    Krauthamer, S. [Jet Propulsion Lab., Pasadena, CA (United States); Das, R. [Jet Propulsion Lab., Pasadena, CA (United States); [California State Univ., Long Beach, CA (United States); Bulawka, A. [Department of Energy, Washington, DC (United States)

    1995-12-31

    PV power applications are currently concentrated in intermediate or residential size for utility-interactive or small stand-alone modes of operation. Consequently, the development of low cost, highly efficient and reliable power conditioning subsystems (PCS) in the small to medium power range is critical for the viability of PV systems as an alternative energy source. The paper summarizes current directions and development efforts in photovoltaic PCS designs and development. It presents new opportunities arising from increased availability and capabilities of semiconductor switching components such as smart power devices and power integrated circuits (PICs). It also describes developmental efforts of manufacturers of these components for various applications and evaluates their synergistic impacts that will assist in required PCS development and will accelerate PV power applications. It is found that the use of these technologies in future PCS designs offers significant promise of improved PCS reliability, cost and performance, thereby making PV AC power more competitive with utility power. The concept of an AC photovoltaic module can be implemented with current technology.

  16. Laser power control system

    SciTech Connect

    Burns, D.H.

    1990-05-22

    This patent describes a method of precisely controlling the power of a laser beam. It comprises: impinging a portion of a laser beam exiting an x-y deflector onto a photodetector, the photodetector generating an electrical feedback signal related to the power of the impinging laser beam exiting the x-y deflector; combining the electrical feedback signal with a video information signal in a servo feedback loop including the x-y deflector and a single acousto-optical modulator to produce an acousto-optical modulator control error signal; and supplying the modulator control error signal to the single acousto-optical modulator; the control signal controlling the single acousto-optical modulator to reduce the error signal produced in the servo feedback loop to substantially zero thereby adjusting the power level of the laser beam to a predetermined level.

  17. Distributed generation with photovoltaic systems: A utility perspective

    SciTech Connect

    Vigotti, R.

    1998-07-01

    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).

  18. Evaluating word-processing systems

    SciTech Connect

    Reeves, C.A. Jr.

    1983-04-01

    An overview is given on how to evaluate word-processing systems running on small computers and central processors, or as stand-alone systems. Software is compared, and details are given on features the author feels are important in any word processing system, both stand-alones and on computer systems. The paper deals with screen-oriented systems only, and does not cover memory or intelligent typewriters. Also, a brief account is given on how word processing can be used in the records management environment.

  19. Solar powered street lighting system

    Microsoft Academic Search

    1980-01-01

    A solar powered street lighting system is disclosed that is totally independent of any external power supply. Solar panels are connected in such a manner to charge a maintenance-free storage battery with sufficient capacity to light street lights and\\/or traffic signals. An auxiliary generator may also be provided having a wind driven vane for also charging the battery if sufficient

  20. Power transaction issues in deregulated power systems 

    E-print Network

    Roycourt, Henrik

    2000-01-01

    With the introduction of the deregulation in the power industry, it becomes possible to wheel power across the transmission network. Hence, some issues involving the network's physical capability to transfer power and the allocation of the network...

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

    NASA Technical Reports Server (NTRS)

    Zhu, Minshao

    2002-01-01

    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.

  2. Model for energy conversion in renewable energy system with hydrogen storage

    NASA Astrophysics Data System (ADS)

    Kélouwani, S.; Agbossou, K.; Chahine, R.

    A dynamic model for a stand-alone renewable energy system with hydrogen storage (RESHS) is developed. In this system, surplus energy available from a photovoltaic array and a wind turbine generator is stored in the form of hydrogen, produced via an electrolyzer. When the energy production from the wind turbine and the photovoltaic array is not enough to meet the load demand, the stored hydrogen can then be converted by a fuel cell to produce electricity. In this system, batteries are used as energy buffers or for short time storage. To study the behavior of such a system, a complete model is developed by integrating individual sub-models of the fuel cell, the electrolyzer, the power conditioning units, the hydrogen storage system, and the batteries (used as an energy buffer). The sub-models are valid for transient and steady state analysis as a function of voltage, current, and temperature. A comparison between experimental measurements and simulation results is given. The model is useful for building effective algorithms for the management, control and optimization of stand-alone RESHSs.

  3. Computer Center: CIBE Systems.

    ERIC Educational Resources Information Center

    Crovello, Theodore J.

    1982-01-01

    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…

  4. The ac power system testbed

    NASA Technical Reports Server (NTRS)

    Mildice, J.; Sundberg, R.

    1987-01-01

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

  5. How the systems approach is determining automotive battery design and use

    NASA Astrophysics Data System (ADS)

    Bonnet, Jean; Stephany, Jean-Marie; Sheppelman, Todd

    Today, the battery in a vehicle system is specific and designed as a single, stand-alone vehicle product. Traditionally, customer specifications were the driving force behind battery design and application requirements. This method is not able to comprehend the fluctuating requirements of real-time, vehicle systems. Growing competition in the automotive market is increasing customer needs and expectations in regards to cost, weight, size efficiency, time-to-market, and quality of the products and systems. System engineering is a service that Delco Remy, as an electrical power system supplier, offers to help their customers secure gains in the market place. System development and application engineering is essential for the development of performance-optimized components that meet the systems and total vehicle cost, reliability and timing objectives. The battery integration must be managed through the electrical power system during the complete vehicle development process in order to increase ultimately customer satisfaction.

  6. The Ames Power Monitoring System

    NASA Technical Reports Server (NTRS)

    Osetinsky, Leonid; Wang, David

    2003-01-01

    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.

  7. Waste Heat Recovery Power Generation with WOWGen

    E-print Network

    Romero, M.

    or combinations of sources can be used to generate power. WOWGen? can also be used with stand alone power plants burning fossil fuels or using renewable energy sources such as solar and biomass. Technology W O W has two patents on WOWGen? power generation....223.1338 Email: Hmromero@WOWenergies.comH URL: Hwww.WOWenergies.com Industry Energy Efficiency Products WOWGen? - Waste Heat Recovery WOWClean? - Pollution control Intellectual Property Two Patents issued Trade secrets ESL-IE-09...

  8. Hybrid Power Management System and Method

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J. (Inventor)

    2008-01-01

    A system and method for hybrid power management. The system includes photovoltaic cells, ultracapacitors, and pulse generators. In one embodiment, the hybrid power management system is used to provide power for a highway safety flasher.

  9. Solar-Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  10. Power Systems Stability Control : Reinforcement Learning Framework

    E-print Network

    Wehenkel, Louis

    with the real power system and the off-line mode in which the interaction occurs with a simulation model of the real power system. We present two case studies made on a 4- machine power system model. The first one, an application of multi-agent systems to the development of a new defense system able to assess power system

  11. RECENT DEVELOPMENTS IN PULSED HIGH POWER SYSTEMS

    Microsoft Academic Search

    David E. Anderson

    2010-01-01

    Pulsed power systems are inherent in any high power accelerator system. Applications include, among others, modulators for powering high power klystrons, pulsed power systems to drive linear induction accelerating cells, kicker magnet drivers for storage rings, and a wide variety of beam deflection and pulsed focusing systems. As with many enabling technologies, component limitations and materials properties dominate the engineering

  12. Solar-powered cooling system

    DOEpatents

    Farmer, Joseph C

    2013-12-24

    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.

  13. Improved thermophotovoltaic power system

    NASA Astrophysics Data System (ADS)

    Horne, W. E.; Day, A. C.; Crabtree, L.

    Improvements in thermophotovoltaic (TPV) system design to ease the geometry and performance requirements are discussed. A TPV system usually consists of a receiver cavity lined with reflective materials and Si solar cells. A suspended central absorber/radiator converter absorbs solar energy and heats to an equilibrium temperature of 2000-23,000 K. Radiant heat at that temperature is well matched to Si solar cell low energy excitation. An elliptical geometry cavity is described which bypasses normal cell mounting problems by having the cells fixed to a plate positioned between the loci of the cavity. Incoming concentrated solar flux is absorbed by the absorber/radiator, which emits the radiation for reflection from the cavity walls to eventually pass through the solar cell wall. Dielectric stack coatings can be used on the walls. A theoretical model was developed for the performance and verified with a laboratory apparatus. Efficiencies of nearly 30% were found practical with existing materials and technologies.

  14. Models for multimegawatt space power systems

    SciTech Connect

    Edenburn, M.W.

    1990-06-01

    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.

  15. Modeling of power electronic systems with EMTP

    NASA Technical Reports Server (NTRS)

    Tam, Kwa-Sur; Dravid, Narayan V.

    1989-01-01

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

  16. Power system optimal reactive power dispatch using evolutionary programming

    SciTech Connect

    Wu, Q.H.; Ma, J.T. [Loughborough Univ. of Technology (United Kingdom). Dept. of Mathematical Sciences] [Loughborough Univ. of Technology (United Kingdom). Dept. of Mathematical Sciences

    1995-08-01

    This paper is concerned with application of evolutionary programming (EP) to optimal reactive power dispatch and voltage control of power systems. Practical implementation of the EP for global optimization problems of large-scale power systems has been considered. The proposed EP method has been evaluated on the IEEE 30-bus system. Simulation results, compared with that obtained using a conventional gradient-based optimization method, are presented to show the potential of applications of the proposed method to power system economical operations.

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

    SciTech Connect

    NONE

    1997-08-01

    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.

  18. Multi-Mission Power Analysis Tool (MMPAT) Version 3

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  19. 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

    ERIC Educational Resources Information Center

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

    2013-01-01

    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.…

  20. Visualizations for Power System Contingency Analysis Data

    E-print Network

    Visualizations for Power System Contingency Analysis Data Yan Sun, Student Member, IEEE Thomas J. Overbye, Senior Member, IEEE Abstract--Contingency analysis (CA) is critical in many routine power system Terms--Contingency Analysis, Power System Visualizations, Power System Operations, User Interfaces I

  1. A GREENFIELD APPROACH FOR FUTURE POWER SYSTEMS

    Microsoft Academic Search

    M. GEIDL; P. FAVRE-PERROD; B. KLÖCKL; G. KOEPPEL

    SUMMARY Recent developments in electric power system technology, power electronics, and informa- tion technology motivate researchers to reconsider today' s power delivery systems. Emerging technologies for transmission, conversion and storage of energy constitute an opportunity for power system improvement. Traditional systems are not deemed to meet future requirements in terms of economic and environmental sustainability. Therefore the authors' institution initiated

  2. Space power systems - 'Spacecraft 2000'

    NASA Technical Reports Server (NTRS)

    Faymon, K. A.

    1985-01-01

    The program 'Spacecraft 2000' has the objective to identify critical, high-payoff, potential spacecraft technologies, taking into account the formulation, advocation, and the management of the requisite technology development programs. This program represents a joint NASA-industry program. The technology areas addressed by 'Spacecraft 2000' are related to spacecraft power/energy storage, thermal control/thermal management, power management and distribution, autonomous operation-control, on-board system integration, spacecraft environmental interactions, secondary propulsion, communications technologies, a total system response approach, and system-subsystem technology verification. The expected benefits of a development of advanced technologies include decreased spacecraft bus system weights, decreased mission costs, increased reliability/lifetimes, and increased operational flexibility.

  3. ADVANCED POWER SYSTEMS ANALYSIS TOOLS

    Microsoft Academic Search

    Robert R. Jensen; Steven A. Benson; Jason D. Laumb

    2001-01-01

    The use of Energy and Environmental Research Center (EERC) modeling tools and improved analytical methods has provided key information in optimizing advanced power system design and operating conditions for efficiency, producing minimal air pollutant emissions and utilizing a wide range of fossil fuel properties. This project was divided into four tasks: the demonstration of the ash transformation model, upgrading spreadsheet

  4. MEMS Rotary Engine Power System

    Microsoft Academic Search

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

    2003-01-01

    This work presents a project overview and recent research results for the MEMS Rotary Engine Power System project at the Berkeley Sensor & Actuator Center of the University of California at Berkeley. The research motivation for the project is the high specific energy density of hydrocarbon fuels. When compared with the energy density of batteries, hydrocarbon fuels may have as

  5. Analysis of Hybrid Power Systems

    Microsoft Academic Search

    Vivek Venkoba Rao; Chellamuthu Chinnagounder

    2007-01-01

    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

  6. Automated power distribution system hardware. [for space station power supplies

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    An automated power distribution system testbed for the space station common modules has been developed. It incorporates automated control and monitoring of a utility-type power system. Automated power system switchgear, control and sensor hardware requirements, hardware design, test results, and potential applications are discussed. The system is designed so that the automated control and monitoring of the power system is compatible with both a 208-V, 20-kHz single-phase AC system and a high-voltage (120 to 150 V) DC system.

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

    Microsoft Academic Search

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

    2001-01-01

    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.

  8. Applying distributed power modules in telecom systems

    Microsoft Academic Search

    Per Lindman; L. Thorsell

    1996-01-01

    The design of modern decentralized power systems in telecommunication applications are increasingly realized by using distributed DC\\/DC power modules. Power modules are usually characterized by high switching frequencies, which enable the use of small ferrite magnetics and ceramic capacitors to enhance the reliability, the power density, and the possibility of live insertion, all desired features in new power system designs.

  9. Power electronics in automotive electrical systems

    Microsoft Academic Search

    Iftikhar A. Khan

    1996-01-01

    The role of power electronics as an enabling technology for various automotive applications is illustrated with examples. Automotive electrical power systems that address the demands of increased electrical power, improved fuel economy and reduced emissions are discussed. Considerations related to high-efficiency automotive electrical power systems such as the selection of the types of electrical machines and power converters, selection of

  10. An Open Source Power System Analysis Toolbox

    Microsoft Academic Search

    PAT X

    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 non-conventional loads, synchronous

  11. Solar energy power generation system

    SciTech Connect

    Nilsson, J.E.; Cochran, C.D.

    1986-05-06

    A solar energy power generation system is described which consists of: (a) means for collecting and concentrating solar energy; (b) heat storage means; (c) Stirling engine means for producing power; (d) first heat transfer means for receiving the concentrated solar energy and for transferring heat to the heat storage means; and (e) second heat transfer means for controllably transferring heat from the storage means to the Stirling engine means and including a discharge heat pipe means for transferring heat to the Stirling engine means and further including means for inserting and withdrawing the discharge heat pipe means into and out of the heat storage means.

  12. An Implementation of the Salt-Farm Monitoring System Using Wireless Sensor Network

    NASA Astrophysics Data System (ADS)

    Ju, Jonggil; Park, Ingon; Lee, Yongwoong; Cho, Jongsik; Cho, Hyunwook; Yoe, Hyun; Shin, Changsun

    In producing solar salt, natural environmental factors such as temperature, humidity, solar radiation, wind direction, wind speed and rain are essential elements which influence on the productivity and quality of salt. If we can manage the above mentioned environmental elements efficiently, we could achieve improved results in production of salt with good quality. To monitor and manage the natural environments, this paper suggests the Salt-Farm Monitoring System (SFMS) which is operated with renewable energy power. The system collects environmental factors directly from the environmental measure sensors and the sensor nodes. To implement a stand-alone system, we applied solar cell and wind generator to operate this system. Finally, we showed that the SFMS could monitor the salt-farm environments by using wireless sensor nodes and operate correctly without external power supply.

  13. Advanced Radioisotope Power Systems Segmented Thermoelectric Research

    NASA Technical Reports Server (NTRS)

    Caillat, Thierry

    2004-01-01

    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).

  14. Battery backup system for switched power supply

    Microsoft Academic Search

    Swoboda

    1987-01-01

    This patent describes a battery back-up system for an alternating current powered switched power supply, the power supply producing a direct current output, the power supply including a voltage regulator circuit, and the battery back-up system serving to maintain the direct current output from the power supply in the event of an alternating current power interruption, the back-up system including:

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

    NASA Astrophysics Data System (ADS)

    Zhou, Wei

    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

  16. Advanced silicon rich automotive electrical power systems

    Microsoft Academic Search

    Ali Emadi; Mehrdad Ehsani; John M. Miller

    1999-01-01

    In order to optimize automotive fuel economy, emissions, performance, and reliability, the More Electric Vehicles (MEV) concept emphasizes the utilization of electrical power systems instead of mechanical and hydraulic power systems. The proposed More Electric Systems facilitate high power loads and enable the introduction of power electronics in a silicon rich environment. On the other hand, there is a growing

  17. 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

  18. 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

    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

    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

  19. INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME

    E-print Network

    . The mission of the Photovoltaic Power Systems Programme is ,,to enhance the international collaboration obtained by weather forecast models. Digital atlases have been created as integrated information system#12;INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME TASK 2 ­ Performance

  20. Study on photovoltaic power system on ships

    SciTech Connect

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

    1995-11-01

    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.

  1. Network Partition for Distributed Reactive Power Optimization in Power Systems

    Microsoft Academic Search

    Zhongxu Li; Yutian Liu; Rushui Liu; Xinsheng Niu

    2008-01-01

    Reactive power optimization is an important measure to improve the secure and economic performance of power systems. To reduce the dimension of solution space and solve the time-consuming problem more effectively, a network partition method for distributed reactive power optimization is introduced to divide a large-scale power system into several small-scale subsystems. The voltage response of nodes to the perturbation

  2. Radioisotope Power System Pool Concept

    NASA Technical Reports Server (NTRS)

    Rusick, Jeffrey J.; Bolotin, Gary S.

    2015-01-01

    Advanced Radioisotope Power Systems (RPS) for NASA deep space science missions have historically used static thermoelectric-based designs because they are highly reliable, and their radioisotope heat sources can be passively cooled throughout the mission life cycle. Recently, a significant effort to develop a dynamic RPS, the Advanced Stirling Radioisotope Generator (ASRG), was conducted by NASA and the Department of Energy, because Stirling based designs offer energy conversion efficiencies four times higher than heritage thermoelectric designs; and the efficiency would proportionately reduce the amount of radioisotope fuel needed for the same power output. However, the long term reliability of a Stirling based design is a concern compared to thermoelectric designs, because for certain Stirling system architectures the radioisotope heat sources must be actively cooled via the dynamic operation of Stirling converters throughout the mission life cycle. To address this reliability concern, a new dynamic Stirling cycle RPS architecture is proposed called the RPS Pool Concept.

  3. Long endurance underwater power system

    NASA Astrophysics Data System (ADS)

    1989-01-01

    The development and design of deep sea power sources for long endurances (more than 1 year) and moderate power (more than 1 KW) are unique. The best primary battery (Li-thionyl chloride) would involve huge space and weight and the cost of such a system would be prohibitive. Fuel cells with stored gases need a pressure vessel and also quite a large volume and weight. Aquanautics is engaged in developing a power source to a very demanding design. The design would involve a completely open system eliminating the need for a pressure vessel. Aquanautics will capture oxygen from the seawater to be delivered to a fuel cell. The hydrogen generated in this design is envisioned to be from a reaction between aluminum and seawater. Such a completely open system is already available from Alupower, Inc. This provides for a much safer and more compact design than cryogenic hydrogen. Lithium or magnesium can also be used. Both are expensive and lithium is known to be potentially hazardous. Since the last report, there has been major improvement of the technological issue of carrier longevity. The previous carrier had an operational life of 3 days. At present, Aquanautics has discovered a carrier called 23SuzyP which has stable electrochemical performance for over a month.

  4. Optimal Power Management in Wireless Control Systems

    E-print Network

    Plotkin, Joshua B.

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

  5. Automatic calorimetry system monitors RF power

    NASA Technical Reports Server (NTRS)

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

    1969-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    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.

  7. Electrical power generating system. [for windpowered generation

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (inventor)

    1981-01-01

    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.

  8. Modeling Power Systems as Complex Adaptive Systems

    SciTech Connect

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

    2004-12-30

    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.

  9. Stand-Alone Computers Supporting Learning Dialogues in Primary Classrooms

    ERIC Educational Resources Information Center

    Wegerif, Rupert; Littleton, Karen; Jones, Ann

    2003-01-01

    This paper focuses on three distinctive ways in which educational software can support learning dialogues in primary classrooms. After a re-capitulation of published research on Initiation, "Discussion," Response, Feedback (IDRF) exchanges, where the computer is used to stimulate discussion and then direct it through using feedback, we ask if…

  10. Problems, Challenges, Benefits of a Stand-Alone Computer

    Microsoft Academic Search

    A. L. Unmack

    1988-01-01

    For the past five years Northrop has had an almost continual demand for some form of parametric life cycle cost analysis. One of the customers had even requested support for his own parametric analysis and had included request for RCA PRICE data. This created a real problem. Because of the nature of the data, it was not possible to use

  11. Developing a Stand Alone Sun Photometer for Ships and Buoys

    NASA Technical Reports Server (NTRS)

    Porter, John N.

    1997-01-01

    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.

  12. System and method for advanced power management

    DOEpatents

    Atcitty, Stanley (Albuquerque, NM); Symons, Philip C. (Surprise, AZ); Butler, Paul C. (Albuquerque, NM); Corey, Garth P. (Albuquerque, NM)

    2009-07-28

    A power management system is provided that includes a power supply means comprising a plurality of power supply strings, a testing means operably connected to said plurality of power supply strings for evaluating performance characteristics of said plurality of power supply strings, and a control means for monitoring power requirements and comprising a switching means for controlling switching of said plurality of power supply strings to said testing means.

  13. Power system optimal reactive power dispatch using evolutionary programming

    Microsoft Academic Search

    Q. H. Wu; J. T. Ma

    1995-01-01

    This paper is concerned with application of evolutionary programming (EP) to optimal reactive power dispatch and voltage control of power systems. Practical implementation of the EP for global optimization problems of large-scale power systems has been considered. The proposed EP method has been evaluated on the IEEE 30-bus system. Simulation results, compared with those obtained using a conventional gradient-based optimization

  14. MEMS Rotary Engine Power System

    NASA Astrophysics Data System (ADS)

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

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

  15. Power socket programmable circuit breaker system

    Microsoft Academic Search

    H. G. Rodney Tan; A. C. Tan; M. Iriana; V. H. Mok

    2008-01-01

    A power socket programmable circuit breaker (PSPCB) system for electrical appliances and domestic power distribution box is presented in this paper. A prototype of PSPCB system was design and built with a BS1363 standard 3-pin wall power socket to demonstrate the PSPCB concept which allows electrical appliances to plug in and power up from the main supply. The user can

  16. The design of the NEPTUNE power system

    Microsoft Academic Search

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

    2001-01-01

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

  17. Power quality issues in a hybrid power system

    Microsoft Academic Search

    Eduard Muljadi; H. Edward McKenna

    2002-01-01

    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

  18. Impact of Power Generation Uncertainty on Power System Static Performance

    E-print Network

    Liberzon, Daniel

    , and difficult to forecast accurately, they present notable un- certainties to the operation of today's powerImpact of Power Generation Uncertainty on Power System Static Performance Yu Christine Chen, Xichen--The rapid growth in renewable energy resources such as wind and solar generation introduces significant

  19. DYNAMIC MODELLING OF AUTONOMOUS POWER SYSTEMS INCLUDING RENEWABLE POWER SOURCES.

    E-print Network

    Paris-Sud XI, Université de

    system components are developed. Emphasis is given in the representation of different hydro power plant of renewable energies for electricity production presents a growing interest, especially in autonomous power (thermal, gas, diesel) and renewable (hydro, wind) power units. The objective is to assess the impact

  20. Uninterruptible power supply (UPS) systems

    SciTech Connect

    NONE

    1997-04-01

    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.

  1. Wind Speed Forecasting for Power System Operation 

    E-print Network

    Zhu, Xinxin

    2013-07-22

    In order to support large-scale integration of wind power into current electric energy system, accurate wind speed forecasting is essential, because the high variation and limited predictability of wind pose profound challenges to the power system...

  2. SITE ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    E.P. McCann

    1999-04-16

    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.

  3. PV powering a weather station for severe weather

    SciTech Connect

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

    1997-12-31

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

  4. Laser power conversion system analysis, volume 1

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    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.

  5. X2000 power system electronics development

    NASA Technical Reports Server (NTRS)

    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

    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.

  6. Wind Power Systems 1.0 Overview

    E-print Network

    Ding, Yu

    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

  7. Interconnected power system laboratory: fault analysis experiment

    Microsoft Academic Search

    S. P. Carullo; R. Bolkus; J. Hartle; J. Foy; C. O. Nwankpa; R. Fischl; J. Gillerman

    1996-01-01

    The primary goal of the project is to develop a fault analysis experiment which allows students to examine the effect of fault conditions on a power system in a realistic manner. This experiment is the first in a series of experiments to be implemented in Drexel University's Interconnected Power Systems Laboratory (IPSL). The IPSL provides a real-life power system network

  8. Nova pulse power system description and status

    SciTech Connect

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

    1981-06-01

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

  9. Aircraft Fuel Cell Power Systems

    NASA Technical Reports Server (NTRS)

    Needham, Robert

    2004-01-01

    In recent years, fuel cells have been explored for use in aircraft. While the weight and size of fuel cells allows only the smallest of aircraft to use fuel cells for their primary engines, fuel cells have showed promise for use as auxiliary power units (APUs), which power aircraft accessories and serve as an electrical backup in case of an engine failure. Fuel cell MUS are both more efficient and emit fewer pollutants. However, sea-level fuel cells need modifications to be properly used in aircraft applications. At high altitudes, the ambient air has a much lower pressure than at sea level, which makes it much more difficult to get air into the fuel cell to react and produce electricity. Compressors can be used to pressurize the air, but this leads to added weight, volume, and power usage, all of which are undesirable things. Another problem is that fuel cells require hydrogen to create electricity, and ever since the Hindenburg burst into flames, aircraft carrying large quantities of hydrogen have not been in high demand. However, jet fuel is a hydrocarbon, so it is possible to reform it into hydrogen. Since jet fuel is already used to power conventional APUs, it is very convenient to use this to generate the hydrogen for fuel-cell-based APUs. Fuel cells also tend to get large and heavy when used for applications that require a large amount of power. Reducing the size and weight becomes especially beneficial when it comes to fuel cells for aircraft. My goal this summer is to work on several aspects of Aircraft Fuel Cell Power System project. My first goal is to perform checks on a newly built injector rig designed to test different catalysts to determine the best setup for reforming Jet-A fuel into hydrogen. These checks include testing various thermocouples, transmitters, and transducers, as well making sure that the rig was actually built to the design specifications. These checks will help to ensure that the rig will operate properly and give correct results when it is finally ready for testing. Another of my goals is to test new membranes for use in proton-exchange membrane fuel cells, in the hope that these membranes can increase the electricity that is produced by he1 cells. Producing more electricity means that fewer fuel cells are needed, thus reducing the weight and volume of an APU based on fuel cells, making such an APU much more viable.

  10. An Open Source Power System Analysis Toolbox

    Microsoft Academic Search

    Federico Milano

    2005-01-01

    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,

  11. Capacitors for Pulsed Power Systems

    NASA Astrophysics Data System (ADS)

    Ratakhin, N. A.; Fedushchak, V. F.

    2002-12-01

    Experimental models of capacitors meant for using in directly operated pulsed power systems with energy supply time to load of 500 ns have been designed. It is supposed that the capacitor with energy output of 20 kJ would be rather perspective used as an elementary unit in such systems. At present time, an intermediate model HCEIcap50-4 is being tested and prototype units HCEIcap100-2 have been manufactured. Capacitors consist of plain sections of 2,5 m in length. The sections have a combined insulation, i.e. paper-film insulation with paper and mylar film. The expected characteristics of HCEIcap100-2 are as follows: capacity is 2?F, voltage is 100 kV, current is 1 MA. The results of the first static testing are presented. A specially adapted for the capacitor low-inductance switch to form a unitary high-current module is being developed.

  12. Coal and biomass to fuels and power.

    PubMed

    Williams, Robert H; Liu, Guangjian; Kreutz, Thomas G; Larson, Eric D

    2011-01-01

    Systems with CO(2) capture and storage (CCS) that coproduce transportation fuels and electricity from coal plus biomass can address simultaneously challenges of climate change from fossil energy and dependence on imported oil. Under a strong carbon policy, such systems can provide competitively clean low-carbon energy from secure domestic feedstocks by exploiting the negative emissions benefit of underground storage of biomass-derived CO(2), the low cost of coal, the scale economies of coal energy conversion, the inherently low cost of CO(2) capture, the thermodynamic advantages of coproduction, and expected high oil prices. Such systems require much less biomass to make low-carbon fuels than do biofuels processes. The economics are especially attractive when these coproduction systems are deployed as alternatives to CCS for stand-alone fossil fuel power plants. If CCS proves to be viable as a major carbon mitigation option, the main obstacles to deployment of coproduction systems as power generators would be institutional. PMID:22432630

  13. Nuclear excited power generation system

    SciTech Connect

    Parker, R.Z.; Cox, J.D.

    1989-03-28

    A power generation system is described, comprising: a gaseous core nuclear reactor; means for passing helium through the reactor, the helium being excited and forming alpha particles by high frequency radiation from the core of the gaseous core nuclear reactor; a reaction chamber; means for coupling chlorine and hydrogen to the reaction chamber, the helium and alpha particles energizing the chlorine and hydrogen to form a high temperature, high pressure hydrogen chloride plasma; means for converting the plasma to electromechanical energy; means for coupling the helium back to the gaseous core nuclear reactor; and means for disassociating the hydrogen chloride to form molecular hydrogen and chlorine, to be coupled back to the reaction chamber in a closed loop. The patent also describes a power generation system comprising: a gaseous core nuclear reactor; means for passing hydrogen through the reactor, the hydrogen being excited by high frequency radiation from the core; means for coupling chlorine to a reaction chamber, the hydrogen energizing the chlorine in the chamber to form a high temperature, high pressure hydrogen chloride plasma; means for converting the plasma to electromechanical energy; means for disassociating the hydrogen chloride to form molecular hydrogen and chlorine, and means for coupling the hydrogen back to the gaseous core nuclear reactor in a closed loop.

  14. Power system characteristics for more electric aircraft

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1993-01-01

    It should not be suprising that more electric aircraft must meet significantly more difficult electrical power system requirements than were considereed when today's power distribution systems were being developed. Electric power, no longer a secondary system, will become a critical element of the primary control system. Functional reliability requiirements will be extremely stringent and can only be met by controlling element redundancy within a distributed power system. Existing electrical systems were not developed to have both the power system and the control/sensing elements distributed and yet meet the requirements of lighting tolerance and high intensity radio frequency (HIRF). In addition, the operation of electric actuators involves high transient loading and reverse energy flows. Such phenomena were also not anticipated when power quality was specified for either 270 vdc or 400 Hertz ac power systems. This paper will expand upon the issues and discuss some of the technologies involved in their resolution.

  15. Captive Water Current Power System

    SciTech Connect

    Wuenscher, H. F.; Wuenscher, H. A.

    1984-01-31

    Current energy is converted into shaft power in two stages; First, buoyant power units with stationary hydrofoil wings reach faster than the current speed by sweeping out a captive path. Second, turbines at said power units convert the fast relative local current into shaft power. Power units sweeping along the water surface, using cycloidal turbine methods, as well as power units sweeping on a submerged path, using axial flow turbine methods, are described.

  16. Space Weather Situational Awareness for Power Systems

    NASA Astrophysics Data System (ADS)

    Boteler, David; Marti, Luis

    2012-07-01

    Space weather, through the production of geomagnetic disturbances, has the potential to cause problems to the operation of high voltage power transmission networks on the ground. A space weather situational awareness tool has been developed for Canadian power utilities to provide power system operators with the information to make informed decisions to maintain system integrity during a space weather event. During geomagnetic disturbances electric currents induced in the power grid can cause partial satuartion of transformers causing increased harmonics and reactive power consumption that can cause misoperation of relays and voltage sags that interfere with system operation. This presentation will describe the development of a system for real-time simulation of geomagnetically induced currents in a power network and how this is being integrated with power system information into a comprehensive situation awareness tool for use in power system control centres.

  17. Direct FuelCell/Turbine Power Plant

    SciTech Connect

    Hossein Ghezel-Ayagh

    2004-11-19

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

  18. Interconnected power system laboratory: Fault analysis experiment

    SciTech Connect

    Carullo, S.P.; Bolkus, R.; Hartle, J.; Foy, J.; Nwankpa, C.O.; Fischl, R. [Drexel Univ., Philadelphia, PA (United States). Dept. of Electrical and Computer Engineering] [Drexel Univ., Philadelphia, PA (United States). Dept. of Electrical and Computer Engineering; Gillerman, J. [Dranetz Technology, Inc., Edison, NJ (United States)] [Dranetz Technology, Inc., Edison, NJ (United States)

    1996-11-01

    The primary goal of the project is to develop a fault analysis experiment which allows students to examine the effect of fault conditions on a power system in a realistic manner. This experiment is the first in a series of experiments to be implemented in Drexel University`s Interconnected Power Systems Laboratory (IPSL). The IPSL provides a real-life power system network and a computer interface to the system in order to provide control and data capturing. The computer interface utilizes client/server and industry standard networking technology to help students visualize power system phenomena as seen by the system operator via an Energy Management System (EMS).

  19. A reactive power optimization solution with max power margin for shipboard power system based on CPSO

    Microsoft Academic Search

    Chuan Wang; Yancheng Liu; Xinxiang Pan

    2009-01-01

    A formulation of the optimal reactive power flow problem for shipboard power system and results from tests of the chaos particle swarm optimization (CPSO) algorithm are presented in this paper. The objective function of the mathematical model minimizes the real power losses and voltage collapse risk by evaluating linearized reactive power margin index of weak node or nodes. Reactive power

  20. Power Control Algorithms for Satellite Communication Systems

    Microsoft Academic Search

    A. Ince; D. Brown; J. Midgley

    1976-01-01

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

  1. Low power systems for wireless microsensors

    Microsoft Academic Search

    K. Bult; Amit Burstein; D. Chang; Michael J. Dong; M. Fielding; E. Kruglick; J. Ho; F. Lin; T. H. Lin; William J. Kaiser; H. Marcy; R. Mukai; Phyllis R. Nelson; F. L. Newburg; Kristofer S. J. Pister; Gregory J. Pottie; Henry Sanchez; Oscar M. Stafsudd; K. Tan; S. Xue; J. Yao

    1996-01-01

    Low power wireless sensor networks pro- vide a new monitoring and control capability for civil and military applications in transportation, manufactur- ing, biomedical, environmental management, and safety and security systems. Wireless microsensor network nodes, operating at average and peak power levels con- strained by compact power sources, offer a range of important challenges for low power methods. This paper reports

  2. 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

  3. Reliability of emergency ac power systems at nuclear power plants

    SciTech Connect

    Battle, R E; Campbell, D J

    1983-07-01

    Reliability of emergency onsite ac power systems at nuclear power plants has been questioned within the Nuclear Regulatory Commission (NRC) because of the number of diesel generator failures reported by nuclear plant licensees and the reactor core damage that could result from diesel failure during an emergency. This report contains the results of a reliability analysis of the onsite ac power system, and it uses the results of a separate analysis of offsite power systems to calculate the expected frequency of station blackout. Included is a design and operating experience review. Eighteen plants representative of typical onsite ac power systems and ten generic designs were selected to be modeled by fault trees. Operating experience data were collected from the NRC files and from nuclear plant licensee responses to a questionnaire sent out for this project.

  4. Profiles in Power: Optimizing Real-Time Systems for Power

    Microsoft Academic Search

    Graham R. Hellestrand; Mahdi Seddighnezhad; James E. Brogan

    High-performance, timing accurate models of complex systems (called Virtual System Prototypes (VSP)) enable the computation of relatively accurate power in terms of events that occur in the model. VSPs are the integrations of models of electronic hardware, communication and mechanical subsystems into systems that execute software accurately. Software has a first order impact on system performance and has, typically, the

  5. Development of preliminary design concept for a multifunction display and control system for the Orbiter crew station. Task 4: Design concept recommendation

    NASA Technical Reports Server (NTRS)

    Spiger, R. J.; Farrell, R. J.; Holcomb, G. A.

    1982-01-01

    Application of multifunction display and control systems to the NASA Orbiter spacecraft offers the potential for reducing crew workload and improving the presentation of system status and operational data to the crew. A design concept is presented for the application of a multifunction display and control system (MFDCS) to the Orbital Maneuvering System and Electrical Power Distribution and Control System on the Orbiter spacecraft. The MFDCS would provide the capability for automation of procedures, fault prioritization and software reconfiguration of the MFDCS data base. The MFDCS would operate as a stand-alone processor to minimize the impact on the current Orbiter software. Supervisory crew command of all current functions would be retained through the use of several operating modes in the system. Both the design concept and the processes followed in defining the concept are described.

  6. EMERY BIOMASS GASIFICATION POWER SYSTEM

    SciTech Connect

    Benjamin Phillips; Scott Hassett; Harry Gatley

    2002-11-27

    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.

  7. 14 CFR 29.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Power boost and power-operated control system. 29.695 Section 29.695...ROTORCRAFT Design and Construction Control Systems § 29.695 Power boost and power-operated control system. (a) If a power boost...

  8. 14 CFR 29.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Power boost and power-operated control system. 29.695 Section 29.695...ROTORCRAFT Design and Construction Control Systems § 29.695 Power boost and power-operated control system. (a) If a power boost...

  9. 14 CFR 29.695 - Power boost and power-operated control system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Power boost and power-operated control system. 29.695 Section 29.695...ROTORCRAFT Design and Construction Control Systems § 29.695 Power boost and power-operated control system. (a) If a power boost...

  10. Building a space solar power system

    Microsoft Academic Search

    Mitsushige Oda

    2005-01-01

    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

  11. Automation concepts for large space power systems

    Microsoft Academic Search

    M. S. Imamura; D. Aichele; R. L. Anier; R. Moser

    1983-01-01

    A study was undertaken to develop a methodology for analyzing, selecting, and implementing automation functions for multi-hundred-kW photovoltaic power systems intended for manned space station. The study involved identification of generic power system elements and their potential faults, definition of automation functions and their resulting benefits, and partitioning of automation functions between power subsystem, central spacecraft computer, and ground. Automation

  12. A power system for a microsatellite

    Microsoft Academic Search

    Dan Olsson

    1993-01-01

    A power system for a microsatellite was designed for the Space Technology Research Vehicle (STRV-1) mainly aimed at technology demonstration experiments and studies of radiation effects and planned to be launched into geostationary transfer orbit. The low average solar array power (25 W) and the small volume allocation of the power system electronics (2.8 dm cubed) became a challenge when

  13. ECE 418/618 Power System Analysis

    E-print Network

    Bolding, M. Chad

    ECE 418/618 Power System Analysis Fall / 2009 Instructor: Dr. E. B. Makram Office: Rm. 303C Riggs.makram@ces.clemson.edu Location: 226 Riggs Hall, 11:00 ­ 12:15 TTH Text: Analysis of Power Systems John J. Grainger and William D for tests: TEST # 1: September 22, 2009. TEST # 2: October 20, 2009. TEST # 3: November 24, 2009. Power

  14. Bifurcations in a power system model

    Microsoft Academic Search

    ALII H. NAYFEH; A. M. Harb; Char-Ming Chin

    1995-01-01

    Bifurcations are performed for a power system model consisting of two generators feeding a load, which is represented by an induction motor in parallel with a capacitor and a combination of constant power and impedance PQ load. The constant reactive power and the coefficient of the reactive impedance load are used as the control parameters. The response of the system

  15. Multiparameter Bifurcation Analysis of Power Systems

    Microsoft Academic Search

    André A. P. Lerm; Claudio A. Cañizares; Flávio A. B. Lemos

    1998-01-01

    This paper presents a detailed bifurcation analysis of multi-parameter power systems. Equilibrium points are used to evaluate the system eigenvalues and obtain different bifurcation diagrams for two sample systems. The paper studies the influence of hard-limits, AVR droop and reactive power compensation on the local bifurcations of the test systems, using detailed generator models. The stability regions of equilibrium points

  16. Fault analysis of multichannel spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Dugal-Whitehead, Norma R.; Lollar, Louis F.

    1990-01-01

    The NASA Marshall Space Flight Center proposes to implement computer-controlled fault injection into an electrical power system breadboard to study the reactions of the various control elements of this breadboard. Elements under study include the remote power controllers, the algorithms in the control computers, and the artificially intelligent control programs resident in this breadboard. To this end, a study of electrical power system faults is being performed to yield a list of the most common power system faults. The results of this study will be applied to a multichannel high-voltage DC spacecraft power system called the large autonomous spacecraft electrical power system (LASEPS) breadboard. The results of the power system fault study and the planned implementation of these faults into the LASEPS breadboard are described.

  17. New Generation Power System for Space Applications

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    The Deep Space Avionics (DSA) Project is developing a new generation of power system building blocks. Using application specific integrated circuits (ASICs) and power switching modules a scalable power system can be constructed for use on multiple deep space missions including future missions to Mars, comets, Jupiter and its moons. The key developments of the DSA power system effort are five power ASICs and a mod ule for power switching. These components enable a modular and scalab le design approach, which can result in a wide variety of power syste m architectures to meet diverse mission requirements and environments . Each component is radiation hardened to one megarad) total dose. The power switching module can be used for power distribution to regular spacecraft loads, to propulsion valves and actuation of pyrotechnic devices. The number of switching elements per load, pyrotechnic firin gs and valve drivers can be scaled depending on mission needs. Teleme try data is available from the switch module via an I2C data bus. The DSA power system components enable power management and distribution for a variety of power buses and power system architectures employing different types of energy storage and power sources. This paper will describe each power ASIC#s key performance characteristics as well a s recent prototype test results. The power switching module test results will be discussed and will demonstrate its versatility as a multip urpose switch. Finally, the combination of these components will illu strate some of the possible power system architectures achievable fro m small single string systems to large fully redundant systems.

  18. Realistic Specific Power Expectations for Advanced Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.

    2006-01-01

    Radioisotope Power Systems (RPS) are being considered for a wide range of future NASA space science and exploration missions. Generally, RPS offer the advantages of high reliability, long life, and predictable power production regardless of operating environment. Previous RPS, in the form of Radioisotope Thermoelectric Generators (RTG), have been used successfully on many NASA missions including Apollo, Viking, Voyager, and Galileo. NASA is currently evaluating design options for the next generation of RPS. Of particular interest is the use of advanced, higher efficiency power conversion to replace the previous thermoelectric devices. Higher efficiency reduces the quantity of radioisotope fuel and potentially improves the RPS specific power (watts per kilogram). Power conversion options include Segmented Thermoelectric (STE), Stirling, Brayton, and Thermophotovoltaic (TPV). This paper offers an analysis of the advanced 100 watt-class RPS options and provides credible projections for specific power. Based on the analysis presented, RPS specific power values greater than 10 W/kg appear unlikely.

  19. Status of space station power system

    NASA Technical Reports Server (NTRS)

    Baraona, Cosmo R.; Sheibley, Dean W.

    1987-01-01

    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.

  20. Power Monitors: A Framework for System-Level Power Estimation Using Heterogeneous Power Models

    Microsoft Academic Search

    Nikhil Bansal; Kanishka Lahiri; Anand Raghunathan; Srimat T. Chakradhar

    2005-01-01

    Power analysis early in the design cycle is critical for the design of low- power systems. With the move to system-level specifications and design methodologies, there has been significant research interest in system-level power estimation. However, as demonstrated in this paper, the addition of power estimation capabilities to system- level simulation tools can significantly degrade simulation efficiency (upto 8.5X), limit-

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

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

  2. Hybrid power-an enabling technology for future combat systems

    Microsoft Academic Search

    Marilyn M. Freeman

    2000-01-01

    The DARPA Combat Hybrid Power Systems (CHPS) program was established to investigate hybrid electric power systems that might provide all the energy and power needs of improved future combat vehicles-specifically the transient, continuous and pulsed power necessary to drive advanced weapons systems, mobility systems, communications systems and protective systems. By exploiting the benefits of hybrid power, power management and power

  3. Power system with an integrated lubrication circuit

    DOEpatents

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

    2009-11-10

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

  4. Modular Solar Electric Power (MSEP) Systems (Presentation)

    SciTech Connect

    Hassani, V.

    2000-06-18

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

  5. PAC duo system power estimation at ESL

    Microsoft Academic Search

    Wen-Tsan Hsieh; Jen-Chieh Yeh; Shi-Yu Huang

    2010-01-01

    In this work, we develop an electronic system-level (ESL) power estimation framework which uses the specified power model interface. Using the proposed power model interface we can easily integrate the various power models in ESL virtual platform. Designers can choose either the coarse-grained or fine-grained power models according to the trade-off between accuracy and computing cost. The experimental results show

  6. Migrating to the Web: a Web financial information system server

    Microsoft Academic Search

    Seng-cho T Chou

    1998-01-01

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

  7. DIFFERENCIATION ET INTEGRATION DES SYSTEMES COMPTABLES : UNE ETUDE

    E-print Network

    Paris-Sud XI, Université de

    of the integration of accounting information systems. It shows that the strategy is, beyond all other considerations, the primary determinant of integration practices of accounting systems of the companies surveyed, followed are not diversified (or monoactivity) opt more for accounting systems partially integrated or stand-alone while those

  8. A System Independent Graphing Package for Mathematical Functions

    Microsoft Academic Search

    Paul S. Wang

    1990-01-01

    SIG is a compact graphics system for the display of curves and surfaces defined by mathematical formulas in a symbolic system. It is available from Kent State University. SIG consists of two parts: xgraph and mgraph that run as concurrent processes. Xgraph is a stand-alone graphics facility written in C to work with the X Window System. Mgraph is the

  9. Space power facility readiness for Space Station power system testing

    Microsoft Academic Search

    Roger L. Smith

    1995-01-01

    This document provides information which shows that the NASA Lewis Research Center's Space Power Facility (SPF) will be ready to execute the Space Station electric power system thermal vacuum chamber testing. The SPF is located at LeRC West (formerly the Plum Brook Station), Sandusky, Ohio. The SPF is the largest space environmental chamber in the world, having an inside horizontal

  10. Power electronics as efficient interface in dispersed power generation systems

    Microsoft Academic Search

    Frede Blaabjerg; Zhe Chen; S. B. Kjaer

    2004-01-01

    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,

  11. Wind power integration in power systems with transmission bottlenecks

    Microsoft Academic Search

    Julija Matevosyan

    2007-01-01

    The best conditions for the development of wind farms are in remote, open areas with low population density. The transmission system in such areas might not be dimensioned to accommodate additional large-scale power infeed. Furthermore a part of the existing transmission capacity might already be reserved for conventional power plants situated in the same area. In this paper four alternatives

  12. Electric power distribution and load transfer system

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  13. Electric power distribution and load transfer system

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  14. Analysis of control strategies for solar regulators

    Microsoft Academic Search

    V. Salas; M. J. Manzanas; A. Lazaro; A. Barrado; E. Olias

    2002-01-01

    This paper presents the study of conditioning power systems applied to stand-alone systems, including maximum power point trackers (MPPT's), simulated and evaluated using simulating tool Simulink®. It is supposed to be integrated on a photovoltaic stand-alone system. Since space and weight are very limited in the environment of a moving vehicle it is very important to maximize the efficiency of

  15. Optimization of hybrid PV\\/wind energy system using Meta Particle Swarm Optimization (MPSO)

    Microsoft Academic Search

    Ajay Kumar Bansal; R. A. Gupta; Rajesh Kumar

    2011-01-01

    When the stand alone energy system having photovoltaic panels only or wind turbine only are compared with the hybrid PV\\/wind energy systems, the hybrid systems are more economical and reliable. Hybrid system can be able to adapt the effects due to climate changes. This paper presents a Artificial Intelligent method to design the hybrid PV\\/wind system. While meeting the basic

  16. Technologies for Lunar Surface Power Systems Power Beaming and Transfer

    NASA Astrophysics Data System (ADS)

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

    2008-01-01

    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.

  17. Smart Power Supply for Battery-Powered Systems

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    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.

  18. Artificial intelligence and space power systems automation

    NASA Technical Reports Server (NTRS)

    Weeks, David J.

    1987-01-01

    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.

  19. Small fission power systems for NEP

    NASA Astrophysics Data System (ADS)

    Lipinski, Ronald J.; Wright, Steven A.; Sherman, Martin P.; Lenard, Roger X.; Marshall, Albert C.; Talandis, Regina A.; Poston, David I.; Kapernick, Richard; Guffee, Ray; Reid, Robert; Elson, Jay; Lee, James

    2002-01-01

    Two nuclear electric propulsion (NEP) power system configurations are presented, each with an output power of 50 kWe and a system mass of about 2500 kg. Both consist of a reactor coupled to a recuperated Brayton power conversion system with a fixed conical radiator driven by loop heat pipes. In one system the reactor is gas-cooled with the gas directly driving the Brayton power conversion system. In the other the reactor is heatpipe-cooled with a heat exchanger between the reactor and the Brayton system. Two variations are described briefly with powers of 100 k We and 150 kWe. The mass scales approximately with the square root of the power. .

  20. Modular, Intelligent Power Systems for Space Exploration

    NASA Technical Reports Server (NTRS)

    Button, Robert

    2006-01-01

    NASA's new Space Exploration Initiative demands that vehicles, habitats, and rovers achieve unprecedented levels of reliability, safety, effectiveness, and affordability. Modular and intelligent electrical power systems are critical to achieving those goals. Modular electrical power systems naturally increase reliability and safety through built-in fault tolerance. These modular systems also enable standardization across a multitude of systems, thereby greatly increasing affordability of the programs. Various technologies being developed to support this new paradigm for space power systems will be presented. Examples include the use of digital control in power electronics to enable better performance and advanced modularity functions such as distributed, master-less control and series input power conversion. Also, digital control and robust communication enables new levels of power system control, stability, fault detection, and health management. Summary results from recent development efforts are presented along with expected future technology development needs required to support NASA's ambitious space exploration goals.

  1. Solar Thermal Power Systems parabolic dish project

    NASA Technical Reports Server (NTRS)

    Truscello, V. C.

    1981-01-01

    The status of the Solar Thermal Power Systems Project for FY 1980 is summarized. Included is: a discussion of the project's goals, program structure, and progress in parabolic dish technology. Analyses and test results of concentrators, receivers, and power converters are discussed. Progress toward the objectives of technology feasibility, technology readiness, system feasibility, and system readiness are covered.

  2. Agent Based Power System Transient Stability Enhancement

    E-print Network

    Pota, Himanshu Roy

    . Hossain and H. R. Pota Abstract--This paper describes an intelligent agent approach to power system fault, various tie lines, large number of electrical devices, etc. So the recent researches indicate a more-agent technology. Index Terms--Multi-agent system, electric power system, fault diagnosis, transient stability

  3. Robust Control for Power System Transient Stability

    Microsoft Academic Search

    Wojtek J. Kolodziej; Dmitry N. KosaevandWenchunZhu; Wenchun Zhu

    1993-01-01

    The complexity of power system transients as well as a wide range of operating regimes are beyond practical limitations of modeling techniques used in control design. Thus, in order to provide reliable system operation, a controller must be insensitive to modelling errors. A study of control design for transient stabilization of interconnected power systems is presented here as viewed by

  4. Power system applications for phasor measurement units

    SciTech Connect

    Burnett, R.O. Jr. (Georgia Power Co., Atlanta, GA (United States)); Butts, M.M.; Sterlina, P.S.

    1994-01-01

    This article examines the applications for a system that can determine the state of the power system at a given instant over any area. The topics of the article include fault recording applications, disturbance recording applications, transmission and generation modeling verification applications, power system stabilizer test applications, and a discussion of future enhancements and applications.

  5. Joint power control in cellular radio systems

    Microsoft Academic Search

    Magnus Frodighl; Jens Zander

    1995-01-01

    Transmitter power control has proven to be an efficient method to control interference and to improve spectrum utilization in cellular and personal communication systems. Previous results have shown that a significantly higher capacity may be reached, even if the system is subject to (practical) power constraints. Since in most cellular systems a duplex link is required, adequate transmission quality has

  6. Multiplex remote information equipment [power system monitoring

    Microsoft Academic Search

    K. Miyatake; H. Yamashita; K. Kitbwaki; H. Suenaga

    1997-01-01

    The Advanced Power Plant Integrated Maintenance Control System (ALICE) has been developed and deployed to perform remote monitoring and control of power equipment and air-conditioning equipment installed in NTT's telecom buildings. At present, there is a need to expand the area that can be supervised by one such system and to improve system reliability and functionality to achieve more efficient

  7. Critical areas: Satellite power systems concepts

    NASA Technical Reports Server (NTRS)

    1975-01-01

    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.

  8. Power Management in Regenerative Life Support Systems

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  9. Underground power line fault locating system

    SciTech Connect

    Fox, L.D.; Flath, R.K.

    1993-08-24

    A method is described of locating a fault in a polyphase power distribution system power distributing power from a bulk power source to power consumers, the power distribution system having a substation feeding a fused switch gear unit, a first vault, and at least one subsequent vault receiving power from the first vault, the first vault distributing power from the fused switch gear unit among plural outgoing underground power lines, each underground outgoing power line supplying power to at least one power consumer, the method comprising the steps of: checking fusing within the fused switch gear unit to determine in which phase the fault has occurred; checking the continuity of a power line interconnecting the fused switch gear unit and the first vault; identifying the fused switch gear unit and the first vault which normally supply power to a line having the fault; installing a fault indicator on each underground outgoing power line of the faulted phase in the first vault and in each subsequent vault; inserting a current limiting fuse in series with and between the fused switch gear unit and the first vault; reenergizing the first vault plural outgoing underground power lines through the current limiting fuse and causing the current limiting fuse to blow; and reading each fault indicator after the reenergizing step to determine the location of the fault. A method according to claim 7 for an underground power distribution system wherein at least one underground outgoing power line delivers power to at least one distribution transformer, wherein the step of installing the fault indicators further comprises installing a fault indicator on each distribution transformer.

  10. System aspects of a Space Nuclear Reactor Power System

    Microsoft Academic Search

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

    1988-01-01

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

  11. Neutral Beam Power System for TPX

    SciTech Connect

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

    1993-11-01

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

  12. Combustion powered thermophotovoltaic emitter system

    SciTech Connect

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

    1995-12-31

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

  13. Power system applications of fiber optics

    NASA Technical Reports Server (NTRS)

    Kirkham, H.; Johnston, A.; Lutes, G.; Daud, T.; Hyland, S.

    1984-01-01

    Power system applications of optical systems, primarily using fiber optics, are reviewed. The first section reviews fibers as components of communication systems. The second section deals with fiber sensors for power systems, reviewing the many ways light sources and fibers can be combined to make measurements. Methods of measuring electric field gradient are discussed. Optical data processing is the subject of the third section, which begins by reviewing some widely different examples and concludes by outlining some potential applications in power systems: fault location in transformers, optical switching for light fired thyristors and fault detection based on the inherent symmetry of most power apparatus. The fourth and final section is concerned with using optical fibers to transmit power to electric equipment in a high voltage situation, potentially replacing expensive high voltage low power transformers. JPL has designed small photodiodes specifically for this purpose, and fabricated and tested several samples. This work is described.

  14. Space Shuttle Upgrades Advanced Hydraulic Power System

    NASA Technical Reports Server (NTRS)

    2004-01-01

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

  15. Nuclear power for space based systems

    NASA Astrophysics Data System (ADS)

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

    1991-09-01

    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.

  16. Solar power satellite system definition study

    NASA Technical Reports Server (NTRS)

    1978-01-01

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

  17. Electric power systems, 3rd ed. , Revised

    SciTech Connect

    Weedy, B.M.

    1987-01-01

    The contents of this book are: Introduction. Basic Concepts. Components of a Power System. Control of Power and Frequency. Control of Voltage and Reactive Power. Load Flows. Fault Analysis. Stability Limits. Direct Current Transmission. Overvoltages and Insulation Requirements. Overhead Lines and Underground Cables. Protection.

  18. A new maximum power point tracking system

    Microsoft Academic Search

    W. J. A. Teulings; J. C. Marpinard; A. Capel; D. O'Sullivan

    1993-01-01

    In power systems involving a load, a battery and a solar array, MPPT (maximum power point tracking) is a promising principle to extract the maximum amount of energy from the solar array and distribute it to the battery and loads. A digital hill-climbing control strategy combined with a bidirectional current mode power cell is presented that makes it possible to

  19. Water reactive hydrogen fuel cell power system

    DOEpatents

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

    2014-11-25

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

  20. Water reactive hydrogen fuel cell power system

    DOEpatents

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

    2014-01-21

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

  1. Continuously charged flywheel type power delivery system

    SciTech Connect

    Frank, A.A.; Omitsu, T.

    1986-04-22

    In a method of controlling the operation of a flywheel-type power delivery system having an energy-storing flywheel, an internal combustion engine is described operatively coupled to the flywheel for delivering power to the flywheel, and a continuously variable ratio transmission operatively coupled to the flywheel for delivering power to an output shaft. The improvement described here consists of: predetermining a desired maximum output shaft speed limit; and adjusting the working displacement of the engine in proportion to the output shaft speed limit, whereby the efficient power output of the engine is tailored to the power requirements of the system.

  2. ON IMPROVED GRAVITY MODELING SUPPORTING DIRECT GEOREFERENCING OF MULTISENSOR SYSTEMS

    Microsoft Academic Search

    Dorota A. Grejner-Brzezinska; Yudan Yi; Charles Toth; Robert Anderson; James Davenport; Damian Kopcha; Richard Salman

    Typically, inertial navigation systems assume the gravity field to be normal (ellipsoidal), meaning that the deflections of the vertical (DOV) are ignored in the gravity compensation procedure. This is one of the primary error sources in inertial navigation, especially detrimental in the stand-alone mode. Errors due to gravity field and system noise grow rather fast in the vertical channel, which

  3. Reference architecture for open and integrated automatic optical inspection systems

    Microsoft Academic Search

    J. B. ZHANG; R. H. WESTON

    1994-01-01

    We examine the role and potential application areas of machine vision inspection systems in the printed circuit board (PCB) manufacturing industry. Available automatic optical inspection (AOI) techniques are reviewed, this revealing limitations which stem mainly from the stand-alone operational nature of the present-generation AOI systems. As a result the authors argue that, fuelled by the need to achieve integration and

  4. ADVANCED POWER SYSTEMS ANALYSIS TOOLS

    SciTech Connect

    Robert R. Jensen; Steven A. Benson; Jason D. Laumb

    2001-08-31

    The use of Energy and Environmental Research Center (EERC) modeling tools and improved analytical methods has provided key information in optimizing advanced power system design and operating conditions for efficiency, producing minimal air pollutant emissions and utilizing a wide range of fossil fuel properties. This project was divided into four tasks: the demonstration of the ash transformation model, upgrading spreadsheet tools, enhancements to analytical capabilities using the scanning electron microscopy (SEM), and improvements to the slag viscosity model. The ash transformation model, Atran, was used to predict the size and composition of ash particles, which has a major impact on the fate of the combustion system. To optimize Atran key factors such as mineral fragmentation and coalescence, the heterogeneous and homogeneous interaction of the organically associated elements must be considered as they are applied to the operating conditions. The resulting model's ash composition compares favorably to measured results. Enhancements to existing EERC spreadsheet application included upgrading interactive spreadsheets to calculate the thermodynamic properties for fuels, reactants, products, and steam with Newton Raphson algorithms to perform calculations on mass, energy, and elemental balances, isentropic expansion of steam, and gasifier equilibrium conditions. Derivative calculations can be performed to estimate fuel heating values, adiabatic flame temperatures, emission factors, comparative fuel costs, and per-unit carbon taxes from fuel analyses. Using state-of-the-art computer-controlled scanning electron microscopes and associated microanalysis systems, a method to determine viscosity using the incorporation of grey-scale binning acquired by the SEM image was developed. The image analysis capabilities of a backscattered electron image can be subdivided into various grey-scale ranges that can be analyzed separately. Since the grey scale's intensity is dependent on the chemistry of the particle, it is possible to map chemically similar areas which can also be related to the viscosity of that compound at temperature. A second method was also developed to determine the elements associated with the organic matrix of the coals, which is currently determined by chemical fractionation. Mineral compositions and mineral densities can be determined for both included and excluded minerals, as well as the fraction of the ash that will be represented by that mineral on a frame-by-frame basis. The slag viscosity model was improved to provide improved predictions of slag viscosity and temperature of critical viscosity for representative Powder River Basin subbituminous and lignite coals.

  5. Laser power beaming systems for lunar surface applications

    NASA Astrophysics Data System (ADS)

    Gill, S. P.; Frye, P.; Rosemary, J.

    A conceptual evaluation of laser power beaming to the lunar surface for power generation is presented. System mass comparisons are made with more conventional surface power systems, and power levels where power beaming is potentially attractive are established.

  6. High power laser apparatus and system

    NASA Technical Reports Server (NTRS)

    Evans, J. C., Jr.; Brandhorst, H. W., Jr. (inventors)

    1975-01-01

    A high-power, continuous-wave laser was designed for use in power transmission and energy-collecting systems, and for producing incoherent light for pumping a laser material. The laser has a high repetitive pulsing rate per unit time, resulting in a high-power density beam. The laser is composed of xenon flash tubes powered by fast-charging capacitors flashed in succession by a high-speed motor connected to an automobile-type distributor.

  7. Low-power systems on chips (SOCs)

    Microsoft Academic Search

    Christian Piguet; Marc Renaudin; Thierry J.-F. Omnés

    2001-01-01

    Low-power Issues for SoCs by Christian Piguet, CSEM . For innovative portable products, Systems on Chips (SoCs) containing several processors, memories and specialised modules are obviously required. Performances but also low-power are main issues in the design of such SoCs. Are these low-power SoCs only constructed with low-power processors, memories and logic blocks? If the latter are unavoidable, many other

  8. High-power VCSEL systems and applications

    NASA Astrophysics Data System (ADS)

    Moench, Holger; Conrads, Ralf; Deppe, Carsten; Derra, Guenther; Gronenborn, Stephan; Gu, Xi; Heusler, Gero; Kolb, Johanna; Miller, Michael; Pekarski, Pavel; Pollmann-Retsch, Jens; Pruijmboom, Armand; Weichmann, Ulrich

    2015-03-01

    Easy system design, compactness and a uniform power distribution define the basic advantages of high power VCSEL systems. Full addressability in space and time add new dimensions for optimization and enable "digital photonic production". Many thermal processes benefit from the improved control i.e. heat is applied exactly where and when it is needed. The compact VCSEL systems can be integrated into most manufacturing equipment, replacing batch processes using large furnaces and reducing energy consumption. This paper will present how recent technological development of high power VCSEL systems will extend efficiency and flexibility of thermal processes and replace not only laser systems, lamps and furnaces but enable new ways of production. High power VCSEL systems are made from many VCSEL chips, each comprising thousands of low power VCSELs. Systems scalable in power from watts to multiple ten kilowatts and with various form factors utilize a common modular building block concept. Designs for reliable high power VCSEL arrays and systems can be developed and tested on each building block level and benefit from the low power density and excellent reliability of the VCSELs. Furthermore advanced assembly concepts aim to reduce the number of individual processes and components and make the whole system even more simple and reliable.

  9. Asset-based system and software system development - A frame-based approach

    Microsoft Academic Search

    Jahangir Karimi; M. K. Zand

    1998-01-01

    Previous works on software reusability has shown that an asset-based systems development strategy to software reuse is effective in identifying reusable design components. This strategy requires moving away from traditional and stand-alone applications development toward an integrated approach. This paper will review previous work on using frames for knowledge representation and will show how an implementation strategy based on the

  10. Power-Quality Monitoring Instrument With FPGA Transducer Compensation

    Microsoft Academic Search

    Antonio Delle Femine; Daniele Gallo; Carmine Landi; Mario Luiso

    2009-01-01

    In this paper, the design and the prototype implementation of a power-quality (PQ) measuring and monitoring instrument based on an embedded controller with reconfigurable I\\/O are described. The instrument performs the calculation of main PQ indexes according to the latest standards, and it can be reconfigured for future standard developments. It is properly implemented to operate in stand-alone mode, and

  11. Automated diagnostics for aerospace power management systems

    SciTech Connect

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

    1995-12-31

    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.

  12. Wind systems for electrical power production

    SciTech Connect

    Thresher, R.W.; Hock, S.M. (National Renewable Energy Lab., Golden, CO (United States))

    1994-08-01

    This article examines the status of wind power plants as a choice for future new electric generation expansion. The topics of the article include wind power plant architecture and control systems, designs of currently available power plants, designs that are in development, and a look at next-generation turbines that will offer changes in blade design, variable-speed operation, advanced generators, advanced control systems, and aerodynamic controls.

  13. Photovoltaic power without batteries for continuous cathodic protection

    NASA Astrophysics Data System (ADS)

    Muehl, W. W., Sr.

    1994-02-01

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

  14. Photovoltaic power without batteries for continuous cathodic protection

    NASA Technical Reports Server (NTRS)

    Muehl, W. W., Sr.

    1994-01-01

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

  15. Power system applications for phasor measurement units

    Microsoft Academic Search

    M. M. Butts; P. S. Sterlina

    1994-01-01

    State-of-the-art technology now permits measurement and analysis of power system performance on a scale not previously possible. Synchronized sampling, derived from the GPS (Global Positioning System), and high accuracy sigma-delta analog-to-digital converters form the basis for a system that can measure the state of the power system at a given instant over any area. Samples are acquired 12 times per

  16. Economic Evaluation of Space Solar Power System

    Microsoft Academic Search

    L. Matsuoka

    2004-01-01

    In this paper, we evaluate the value that the solar panels will be set on the orbit from the economic standpoint and consider the necessity of the Space Solar Power System (SSPS). In order to these evaluations, we compare the SSPS with the photovoltaic power system on the ground (PVPSG). Firstly, we examined the generation cost of the PVPSG. When

  17. Power-conversion system component summation

    Microsoft Academic Search

    T. S. Mroz; M. M. Bailey; J. A. Haller; H. S. Bloomfield; R. J. Stochl; R. E. Hyland

    1979-01-01

    Commercial components applicable to Rankine cycle, Brayton cycle, and Stirling cycle solar thermal power generating systems were surveyed. The solar thermal power generating systems and their components are described. Data on these components are presented and include development status, availability, cost, operating constraints, operating characteristics, and experience factors.

  18. A solar-Stirling small power system

    Microsoft Academic Search

    R. L. Pons

    1979-01-01

    The paper presents results of an in-depth analysis of a 1 MWe solar power system consisting of multiple parabolic dish concentrators employing Stirling cycle engines for power conversion. The engine, ac generator, cavity receiver and integral sodium pool boiler\\/heat transport system are combined in a single package and mounted at the focus of each concentrator. The output of each concentrator

  19. Expert System Detects Power-Distribution Faults

    NASA Technical Reports Server (NTRS)

    Walters, Jerry L.; Quinn, Todd M.

    1994-01-01

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

  20. On-line power system security analysis

    Microsoft Academic Search

    NEAL BALU; TIMOTHY BERTRAM; A. Bose; V. Brandwajn; G. Cauley; D. Curtice; A. Fouad; L. Fink; M. G. Lauby; B. F. Wollenberg; J. N. Wrubel

    1992-01-01

    A broad overview of on-line power system security analysis is provided, with the intent of identifying areas needing additional research and development. Current approaches to state estimation are reviewed and areas needing improvement, such as external system modeling, are discussed. On-line contingency selection has become practical, particularly for static security. Additional work is necessary to identify better indices of power

  1. Fuel cell power system development for submersibles

    Microsoft Academic Search

    R. L. Rosenfeld; P. R. Prokopius; A. P. Meyer

    1992-01-01

    DARPA is sponsoring programs at International Fuel Cells (IFC) to develop proton exchange membrane (PEM) fuel cell power systems for marine application. One program is focused on a fuel cell power system for use in an unmanned underwater vehicle (UUV). Another program, part of DARPA's advanced submarine technology (Subtech) efforts, is developing and demonstrating the technology to generate hydrogen from

  2. Power system planning and reliability. Final report

    Microsoft Academic Search

    J. Peschon; J. C. Kaltenbach; P. Henault; M. W. Siddiqee; L. P. Hajdu

    1968-01-01

    The recent literature on power system reliability has emphasized the importance of sound planning to satisfy future loads. In view of the extremely high investment costs of electric power systems, it is imperative to have procedures for adding the right kind of equipment at the right time in the right location to achieve the desired level of reliability and quality

  3. Intelligent power modules for driving systems [IGBTs

    Microsoft Academic Search

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

    1994-01-01

    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

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

    NASA Technical Reports Server (NTRS)

    DeGregorio, Kelly; Wilson, Dale G.

    2009-01-01

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

  5. Power System Analysis Software Package (PSASP)-an integrated power system analysis tool

    Microsoft Academic Search

    Wu Zhongxi; Zhou Xiaoxin

    1998-01-01

    In this paper, an integrated power system analysis tool called Power System Analysis Software Package (PSASP) is presented. A brief description of every constituent module of PSASP is given first, then user-defined (UD) modeling function and user program interface (UPI) are introduced further. Finally, the new development of PSASP, power system analysis software platform, is illustrated through a diagram

  6. Comparison of solar heat pump systems to conventional methods for residential heating, cooling, and water heating, volume 2

    Microsoft Academic Search

    P. J. Hughes; J. H. Morehouse

    1980-01-01

    The series and parallel combined solar heat pump systems investigated are at best marginally competitive, on a 20 year life cycle cost basis, with conventional oil and electric furnace systems. The combined solar heat pump systems are not economically competitive with conventional gas furnace or stand alone heat pump systems for residential space heating, cooling and water heating. The combined

  7. Enabling Solar System Exploration with Small Radioisotope Power Systems

    Microsoft Academic Search

    R. D. Abelson; T. S. Balint; H. Noravian; J. E. Randolph; C. Satter; G. R. Schmidt; J. H. Shirley

    2005-01-01

    The increased use of smaller spacecraft over the last decade, in combination with studies of potential science applications, has suggested that a wide range of low power missions and applications could be enabled by a new generation of conceptual small radioisotope power systems with power levels in the range of 20 mW to a few 10's of watts. Such systems

  8. QUANTITATIVE RISK REDUCTION ESTIMATION TOOL FOR CONTROL SYSTEMS Suggested Approach and Research Needs

    Microsoft Academic Search

    Miles McQueen; Wayne Boyer; Mark Flynn; Sam Alessi

    For the past year we have applied a variety of risk assessment technologies to evaluate the risk to critical infrastructure from cyber attacks on control systems. More recently, we identified the need for a stand alone control system risk reduction estimation tool to provide owners and operators of control systems with a more useable, reliable, and credible method for managing

  9. It's what it's in: evaluating the usability of large-scale integrated systems

    Microsoft Academic Search

    Steven R. Haynes

    2009-01-01

    Today's systems are often composed of many heterogeneous, distributed components including computing and communications infrastructure, other hardware devices, and system and application software. Evaluating the usability of these systems is difficult, especially in the early stages of development when their use cannot be observed in context. While many different evaluation methods have been proposed for evaluating stand-alone technologies, evaluating very

  10. Space Station Power System Autonomy Demonstration

    NASA Astrophysics Data System (ADS)

    Kish, James A.; Dolce, James L.; Weeks, David J.

    1988-10-01

    The Office of Aeronautics and Space Technology has selected the Space Station Electrical Power System as one of the systems that will participate in the Systems Autonomy Demonstration Project(SADP) 1990 Power/Thermal Demonstration. The purpose of this demonstration is the autonomous operation of two major Space Station systems through the application of cooperating knowledge-based systems technology. Lewis Research Center(LeRC) and Marshall Space Flight Center(MSFC) will first jointly develop an autonomous power system using existing Space Station testbed facilities at each center. The subsequent 1990 power-thermal demonstrationwill then involve the cooperative operation of the LeRC/MSFC power system with the Johnson Space Center(JSC)'s thermal control and DMS/OMS testbed facilities. The testbeds and expert systems at each of the NASA centers will be interconnected via communication links. The appropriate knowledge-based technology will be developed for each testbed and applied to problems requiring inter-system cooperation. Primary emphasis will be focused on failure detection and classification, system reconfiguration, planning and scheduling of electrical power resources and integration of knowledge-based and conventional control system software into the design and operation of Space Station testbeds.

  11. Transient and Steady-state Tests of the Space Power Research Engine with Resistive and Motor Loads

    NASA Technical Reports Server (NTRS)

    Rauch, Jeffrey S.; Kankam, M. David

    1995-01-01

    The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

  12. Static conversion systems. [for space power reactors

    NASA Technical Reports Server (NTRS)

    Ewell, R.; Mondt, J.

    1985-01-01

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

  13. Heatpipe space power and propulsion systems

    SciTech Connect

    Houts, M.G.; Poston, D.I.; Ranken, W.A.

    1995-07-01

    Safe, reliable, low-mass space power and propulsion systems could have numerous civilian and military applications. This paper discusses two fission-powered concepts: the Heatpipe Power System (HPS) that provides power only, and the Heatpipe Bimodal System (HBS) that provides both power and thermal propulsion. Both concepts have 10 important features. First, only existing technology and recently tested fuel forms are used. Second, fuel can be removed whenever desired, greatly facilitating system fabrication and handling. Third, full electrically heated system testing is possible, with minimal operations required to replace the heaters with fuel and ready the system for launch. Fourth, the systems are passively subcritical during launch accidents. Fifth, a modular approach is used, and most technical issues can be resolved with inexpensive module tests. Sixth, bonds between dissimilar metals are minimized. Seventh, there are no single point failures during power mode operation. Eighth, fuel burnup rate is quite low to help ensure greater than 10-year system life. Ninth, there are no pumped coolant loops, and the systems can be shut down and restarted without coolant freeze/thaw concerns. Finally, a full ground nuclear test is not needed, and development costs will be low. The baseline HPS uses SNAP-10A-style thermoelectric power converters to produce 5 kWe at a system mass of about 500 kg. The unicouple thermoelectric converters have a hot shoe temperature of 1275 K and reject waste heat at 775 K. This type of thermoelectric converter has been used extensively by the space program, demonstrating an operational lifetime of decades. At higher thermal power, the same core can produce over 10 kWe using thermoelectric converters, and over 50 kWe using advanced power conversion systems.

  14. TFTR neutral-beam power system

    SciTech Connect

    Winje, R.A.

    1982-10-01

    The TFTR Neutral Beam Power System (NBPS) consists of the accelerator grid power supply and the auxiliary power supplies required to operate the TFTR 120-keV ion sources. The current configuration of the NBPS including the 11-MVA accelerator grid power supply and the Arc and Filament power supplies isolated for operation at accelerator grid voltages up to 120 kV, is described. The prototype NBPS has been assembled at the Princeton Plasma Physics Laboratory and has been operated. The results of the initial operation and the description and resolution of some of the technical problems encountered during the commissioning tests are presented.

  15. Precise timing in electric power systems

    Microsoft Academic Search

    Kenneth E. Martin

    1993-01-01

    Precise timing offers a new approach to system-wide controls. It enables measuring the system-wide AC phase as well as timing events and synchronizing controls. the Global Positioning System (GPS) is the first system to provide timing with enough precision to make this approach practical. GPS also provides the wide area of coverage, continuous availability, and high reliability required for power

  16. Solar powered CP system protects gathering lines

    Microsoft Academic Search

    1983-01-01

    The wholly owned gas transmission subsidiary of Public Service Co. of Colorado has installed 2 solar-powered cathodic protection systems in its Ignacio Gathering System. The system is designed for the level of light available in the winter months when the least amount of sunshine is available. The 6 panel system, voltage regulation, automatic load connection\\/disconnection, and groundbed are described. Solar

  17. Risk assessment of power systems SCADA

    Microsoft Academic Search

    Gomaa Hamoud; Rong-Liang Chen; Ian Bradley

    2003-01-01

    SCADA systems are widely used in power systems for monitoring, operation and control purposes. Failure of the SCADA system can result in severe consequences such as customer load losses and equipment damages, etc. Evaluating these consequences at planning stage can help select the appropriate level of reliability of the SCADA systems. This paper presents a practical method for quantifying the

  18. Survey of aircraft electrical power systems

    NASA Technical Reports Server (NTRS)

    Lee, C. H.; Brandner, J. J.

    1972-01-01

    Areas investigated include: (1) load analysis; (2) power distribution, conversion techniques and generation; (3) design criteria and performance capabilities of hydraulic and pneumatic systems; (4) system control and protection methods; (5) component and heat transfer systems cooling; and (6) electrical system reliability.

  19. Power analysis of embedded operating systems

    Microsoft Academic Search

    Robert P. Dick; Ganesh Lakshminarayana; Anand Raghunathan; Niraj K. Jha

    2000-01-01

    The increasing complexity and software content of embedded systems has led to the frequent use of system software that helps applications access underlying hardware resources easily and efficiently. In this paper, we analyze the power consumption of real-time operating systems (RTOSs), which form an important component of the system software layer. Despite the widespread use of, and significant role played

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

    Microsoft Academic Search

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

    2003-01-01

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