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Sample records for ac power system

  1. AC power systems handbook

    SciTech Connect

    Whitaker, J.

    1991-01-01

    Transient disturbances are what headaches are made of. Whatever you call them-spikes, surges, are power bumps-they can take your equipment down and leave you with a complicated and expensive repair job. Protection against transient disturbances is a science that demands attention to detail. This book explains how the power distribution system works, what can go wrong with it, and how to protect a facility against abnormalities. system grounding and shielding are covered in detail. Each major method of transient protection is analyzed and its relative merits discussed. The book provides a complete look at the critical elements of the ac power system. Provides a complete look at the ac power system from generation to consumption. Discusses the mechanisms that produce transient disturbances and how to protect against them. Presents diagrams to facilitate system design. Covers new areas, such as the extent of the transient disturbance problem, transient protection options, and stand-by power systems.

  2. 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.

  3. 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.

  4. Operation Method for AC Motor Control during Power Interruption in Direct AC/AC Converter System

    NASA Astrophysics Data System (ADS)

    Shizu, Keiichiro; Azuma, Satoshi

    Direct AC/AC converters have been studied due to their potential use in power converters with no DC-link capacitor, which can contribute to the miniaturization of power converters. However, the absence of a DC-link capacitor makes it difficult to control the AC motor during power interruption. First, this paper proposes a system that realizes AC motor control during power interruption by utilizing a clamp capacitor. In general, direct AC/AC converters have a clamp circuit consisting of a rectifier diode(s) and a clamp capacitor in order to avoid over-voltages. In the proposed system, there is an additional semiconductor switch reverse-parallel to the rectifier diode(s), and the clamp capacitor voltage can be utilized for AC motor control by turning on the additional switch. Second, this paper discusses an operation method for AC motor control and clamp capacitor voltage control during power interruption. In the proposed method “DC-link voltage control”, the kinetic energy in the AC motor is transformed into electrical energy and stored in the clamp capacitor; the clamp capacitor is therefore charged and the capacitor voltage is controlled to remain constant at an instruction value. Third, this paper discusses a switching operation during power interruption. A dead-time is introduced between the operation of turning off all switches on the rectifier side and the operation of turning on the additional switch, which prevents the occurrence of a short circuit between the interrupted power source and the clamp capacitor. Finally, experimental results are presented. During power interruptions, an output current was continuously obtained and the clamp capacitor voltage was maintained to be equal to the instruction value of the capacitor voltage. These results indicate that both AC motor control and capacitor voltage control were successfully achieved by using the proposed system.

  5. 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.

  6. Wind-powered asynchronous AC/DC/AC converter system. [for electric power supply regulation

    NASA Technical Reports Server (NTRS)

    Reitan, D. K.

    1973-01-01

    Two asynchronous ac/dc/ac systems are modelled that utilize wind power to drive a variable or constant hertz alternator. The first system employs a high power 60-hertz inverter tie to the large backup supply of the power company to either supplement them from wind energy, storage, or from a combination of both at a preset desired current; rectifier and inverter are identical and operate in either mode depending on the silicon control rectifier firing angle. The second system employs the same rectification but from a 60-hertz alternator arrangement; it provides mainly dc output, some sinusoidal 60-hertz from the wind bus and some high harmonic content 60-hertz from an 800-watt inverter.

  7. High-Frequency ac Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.; Mildice, James

    1987-01-01

    Loads managed automatically under cycle-by-cycle control. 440-V rms, 20-kHz ac power system developed. System flexible, versatile, and "transparent" to user equipment, while maintaining high efficiency and low weight. Electrical source, from dc to 2,200-Hz ac converted to 440-V rms, 20-kHz, single-phase ac. Power distributed through low-inductance cables. Output power either dc or variable ac. Energy transferred per cycle reduced by factor of 50. Number of parts reduced by factor of about 5 and power loss reduced by two-thirds. Factors result in increased reliability and reduced costs. Used in any power-distribution system requiring high efficiency, high reliability, low weight, and flexibility to handle variety of sources and loads.

  8. Power factor control system for AC induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1977-01-01

    A power factor control system for use with ac induction motors was designed which samples lines voltage and current through the motor and decreases power input to the motor proportional to the detected phase displacement between current and voltage. This system provides, less power to the motor, as it is less loaded.

  9. Resonant AC power system proof-of-concept test program

    NASA Technical Reports Server (NTRS)

    Wappes, Loran J.

    1986-01-01

    Proof-of-concept testing was performed on a 20-kHz, resonant power system breadboard from 1981 through 1985. The testing began with the evaluation of a single, 1.0-kW resonant inverter and progressed to the testing of breadboard systems with higher power levels and more capability. The final breadboard configuration tested was a 25.0-kW breadboard with six inverters providing power to three user-interface modules over a 50-meter, 20-kHz bus. The breadboard demonstrated the ability to synchronize multiple resonant inverters to power a common bus. Single-phase and three-phase 20-kHz power distribution was demonstrated. Simple conversion of 20-kHz to dc and variable-frequency ac was demonstrated as was bidirectional power flow between 20-kHz and dc. Steady state measurements of efficiency, power-factor tolerance, and conducted emissions and conducted susceptibility were made. In addition, transient responses were recorded for such conditions as start up, shut down, load changes. The results showed the 20-kHz resonant system to be a desirable technology for a spacecraft power management and distribution system with multiple users and a utility-type bus.

  10. QPSK modulation for AC-power-signal-biased visible light communication system

    NASA Astrophysics Data System (ADS)

    Liu, Yu-Feng; Yeh, Chien-Hung; Chow, Chi-Wai; Liu, Yang

    2013-01-01

    With the integration of light emitting diode (LED), visible light communication (VLC) can provide wireless communication link using the lightning system. Due to the consideration of power efficiency, AC-LED has the design of reducing energy waste with alternating current from the power outlet. In this work, we propose an AC-power-signalbiased system that provides communication on both DC-LED and AC-LED. The bias circuit is designed to combine ACpower signal and the message signal with QPSK format. This driving scheme needs no AC-to-DC converters and it is suitable for driving AC LED. Synchronization is completed to avoid threshold effect of LED.

  11. Design and Control Implementation of AC Electric Power Steering System Test Bench*

    NASA Astrophysics Data System (ADS)

    Zhang, Weidong; Ai, Yibo

    Using AC motor is an important development trend of electric power steering system, and in this paper, we proposed a design of AC electric power steering system test bench. The paper introduced the bench structure, working principle and main components selection first, and then given the implementation scheme of test bench's three functions: simulation of the road resistance, power assistant control and data acquisition. The test results showed the feasibility of the test bench.

  12. Simultaneous distribution of AC and DC power

    DOEpatents

    Polese, Luigi Gentile

    2015-09-15

    A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

  13. Power factor control system for ac induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1981-01-01

    A power control circuit for an induction motor is disclosed in which a servo loop is used to control power input by controlling the power factor of motor operation. The power factor is measured by summing the voltage and current derived square wave signals.

  14. Static state estimation of multiterminal DC/AC power system in rectangular co-ordinates

    SciTech Connect

    Roy, L.; Sinha, A.K. ); Srivastava, H.N.P. )

    1991-01-01

    This paper describes a simple, efficient and reliable method for estimating the state of an integrated multiterminal HVDC/AC power system in the rectangular coordinate form. A six variable model is used to represent the converter system. The proposed algorithm performs successfully in obtaining the state of an AC system with a DC link or a multiterminal DC network. It is possible to implement it for an on-line state estimation. Simulation results of a 30-busbar system are presented for illustration.

  15. System for transmitting low frequency analog signals over AC power lines

    DOEpatents

    Baker, Steven P.; Durall, Robert L.; Haynes, Howard D.

    1989-09-05

    A system for transmitting low frequency analog signals over AC power lines using FM modulation. A low frequency analog signal to be transmitted is first applied to a voltage-to-frequency converter where it is converted to a signal whose frequency varies in proportion to the analog signal amplitude. This signal is then used to modulate the carrier frequency of an FM transmitter coupled to an AC power line. The modulation signal frequency range in selected to be within the response band of the FM transmitter. The FM modulated carrier signal is received by an FM receiver coupled to the AC power line, demodulated and the demodulated signal frequency is converted by a frequency-to-voltage converter back to the form of the original low frequency analog input signal.

  16. A system for tranmitting low frequency analog signals over ac power lines

    DOEpatents

    Baker, S.P.; Durall, R.L.; Haynes, H.D.

    1987-07-30

    A system for transmitting low frequency analog signals over ac power lines using FM modulation. A low frequency analog signal to be transmitted is first applied to a voltage-to-frequency converter where it is converted to a signal whose frequency varies in proportion to the analog signal amplitude. This signal is then used to modulate the carrier frequency of an FM transmitter coupled to an ac power line. The modulation signal frequency range is selected to be within the response band of the FM transmitter. The FM modulated carrier signal is received by an FM receiver coupled to the ac power line, demodulated and the demodulated signal frequency is converted by a frequency-to-voltage converter back to the form of the original low frequency analog input signal. 4 figs.

  17. System for transmitting low frequency analog signals over AC power lines

    DOEpatents

    Baker, Steven P.; Durall, Robert L.; Haynes, Howard D.

    1989-01-01

    A system for transmitting low frequency analog signals over AC power lines using FM modulation. A low frequency analog signal to be transmitted is first applied to a voltage-to-frequency converter where it is converted to a signal whose frequency varies in proportion to the analog signal amplitude. This signal is then used to modulate the carrier frequency of an FM transmitter coupled to an AC power line. The modulation signal frequency range in selected to be within the response band of the FM transmitter. The FM modulated carrier signal is received by an FM receiver coupled to the AC power line, demodulated and the demodulated signal frequency is converted by a frequency-to-voltage converter back to the form of the original low frequency analog input signal.

  18. Development of a uninterrupted power system: ac and dc to dc converter

    NASA Technical Reports Server (NTRS)

    Cronin, D. L.; Schoenfeld, A. D.

    1973-01-01

    This program covered the design, fabrication and testing of an advanced development model uninterrupted power system. The input and output requirements imposed on the power processor were specified such that the unit is electrically interchangeable with existing power systems used by the Federal Aviation Administration in installations which have a history of failure due to electrical transient conditions. Input power is from either of two single-phase ac power sources or batteries with electronic selection and transfer between power sources. Battery reconditioning is automatic when either ac source is present. The output power is rated at 84OW; the nominal output is 24V at 35A. Within the 84OW limit, the regulated output voltage is adjustable from 22V to 30Vdc. Protection against continuous overloading or short circuit is provided. The unit is packaged in a standard 19-inch rack mount configuration with 7-inch panel height. Controls are on the front panel with power input and output through connectors on the rear surface. Cooling is by free convection from fin areas located on the side and rear panels. The packaged unit weighs 52.8 lbs., which can be reduced significantly if a three-phase ac power source is used.

  19. A study of some features of ac and dc electric power systems for a space station

    NASA Technical Reports Server (NTRS)

    Hanania, J. I.

    1983-01-01

    This study analyzes certain selected topics in rival dc and high frequency ac electric power systems for a Space Station. The interaction between the Space Station and the plasma environment is analyzed, leading to a limit on the voltage for the solar array and a potential problem with resonance coupling at high frequencies. Certain problems are pointed out in the concept of a rotary transformer, and further development work is indicated in connection with dc circuit switching, special design of a transmission conductor for the ac system, and electric motors. The question of electric shock hazards, particularly at high frequency, is also explored. and a problem with reduced skin resistance and therefore increased hazard with high frequency ac is pointed out. The study concludes with a comparison of the main advantages and disadvantages of the two rival systems, and it is suggested that the choice between the two should be made after further studies and development work are completed.

  20. Electromechanical systems with transient high power response operating from a resonant ac link

    NASA Technical Reports Server (NTRS)

    Burrows, Linda M.; Hansen, Irving G.

    1992-01-01

    The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant ac link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control all four operating quadrants. Incorporating the ac link allows the converter in these systems to switch at the zero crossing of every half cycle of the ac waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed under contract to NASA.

  1. Tevatron AC dipole system

    SciTech Connect

    Miyamoto, R.; Kopp, S.E.; Jansson, A.; Syphers, M.J.; /Fermilab

    2007-06-01

    The AC dipole is an oscillating dipole magnet which can induce large amplitude oscillations without the emittance growth and decoherence. These properties make it a good tool to measure optics of a hadron synchrotron. The vertical AC dipole for the Tevatron is powered by an inexpensive high power audio amplifier since its operating frequency is approximately 20 kHz. The magnet is incorporated into a parallel resonant system to maximize the current. The use of a vertical pinger magnet which has been installed in the Tevatron made the cost relatively inexpensive. Recently, the initial system was upgraded with a more powerful amplifier and oscillation amplitudes up to 2-3{sigma} were achieved with the 980 GeV proton beam. This paper discusses details of the Tevatron AC dipole system and also shows its test results.

  2. Electromechanical systems with transient high power response operating from a resonant AC link

    NASA Technical Reports Server (NTRS)

    Burrows, Linda M.; Hansen, Irving G.

    1992-01-01

    The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant AC link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control in all four operating quadrants. Incorporating the AC link allows the converter in these systems to switch at the zero crossing of every half cycle of the AC waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed by LeRC and General Dynamics Space Systems Division under contract to NASA. A description of a single motor, electromechanical actuation system is presented. Then, focus is on a conceptual design for an AC electric vehicle. This design incorporates an induction motor/generator together with a flywheel for peak energy storage. System operation and implications along with the associated circuitry are addressed. Such a system would greatly improve all-electric vehicle ranges over the Federal Urban Driving Cycle (FUD).

  3. Nonlinear control of voltage source converters in AC-DC power system.

    PubMed

    Dash, P K; Nayak, N

    2014-07-01

    This paper presents the design of a robust nonlinear controller for a parallel AC-DC power system using a Lyapunov function-based sliding mode control (LYPSMC) strategy. The inputs for the proposed control scheme are the DC voltage and reactive power errors at the converter station and the active and reactive power errors at the inverter station of the voltage-source converter-based high voltage direct current transmission (VSC-HVDC) link. The stability and robust tracking of the system parameters are ensured by applying the Lyapunov direct method. Also the gains of the sliding mode control (SMC) are made adaptive using the stability conditions of the Lyapunov function. The proposed control strategy offers invariant stability to a class of systems having modeling uncertainties due to parameter changes and exogenous inputs. Comprehensive computer simulations are carried out to verify the proposed control scheme under several system disturbances like changes in short-circuit ratio, converter parametric changes, and faults on the converter and inverter buses for single generating system connected to the power grid in a single machine infinite-bus AC-DC network and also for a 3-machine two-area power system. Furthermore, a second order super twisting sliding mode control scheme has been presented in this paper that provides a higher degree of nonlinearity than the LYPSMC and damps faster the converter and inverter voltage and power oscillations. PMID:24906895

  4. 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.

  5. High power switch mode linear amplifiers for flexible ac transmission system

    SciTech Connect

    Mwinyiwiwa, B.; Wolanski, Z.; Ooi, B.T.

    1996-10-01

    The Pulse Width Modulation (PWM) technique has been proposed for the force-commutated Shunt and Series VAR Controllers and Unified Power Flow Controllers in Flexible AC Transmission Systems. The PWM converters can be operated as linear amplifiers of constant gain so that treasure trove of linear control system theory can be brought to bear more easily when applying feedback controls. For example, pole-placement and active filtering have been successfully applied in laboratory models. This paper is written as a tutorial describing the stages of signal processing: modulation, amplification and demodulation, without reference to power electronics since the solid-state switches are modelled as ON-OFF switches.

  6. Very low noise AC/DC power supply systems for large detector arrays

    NASA Astrophysics Data System (ADS)

    Arnaboldi, C.; Baù, A.; Carniti, P.; Cassina, L.; Giachero, A.; Gotti, C.; Maino, M.; Passerini, A.; Pessina, G.

    2015-12-01

    In this work, we present the first part of the power supply system for the CUORE and LUCIFER arrays of bolometric detectors. For CUORE, it consists of AC/DC commercial power supplies (0-60 V output) followed by custom DC/DC modules (48 V input, ±5 V to ±13.5 V outputs). Each module has 3 floating and independently configurable output voltages. In LUCIFER, the AC/DC + DC/DC stages are combined into a commercial medium-power AC/DC source. At the outputs of both setups, we introduced filters with the aim of lowering the noise and to protect the following stages from high voltage spikes that can be generated by the energy stored in the cables after the release of accidental short circuits. Output noise is very low, as required: in the 100 MHz bandwidth the RMS level is about 37 μVRMS (CUORE setup) and 90 μVRMS (LUCIFER setup) at a load of 7 A, with a negligible dependence on the load current. Even more importantly, high frequency switching disturbances are almost completely suppressed. The efficiency of both systems is above 85%. Both systems are completely programmable and monitored via CAN bus (optically coupled).

  7. Very low noise AC/DC power supply systems for large detector arrays.

    PubMed

    Arnaboldi, C; Baù, A; Carniti, P; Cassina, L; Giachero, A; Gotti, C; Maino, M; Passerini, A; Pessina, G

    2015-12-01

    In this work, we present the first part of the power supply system for the CUORE and LUCIFER arrays of bolometric detectors. For CUORE, it consists of AC/DC commercial power supplies (0-60 V output) followed by custom DC/DC modules (48 V input, ±5 V to ±13.5 V outputs). Each module has 3 floating and independently configurable output voltages. In LUCIFER, the AC/DC + DC/DC stages are combined into a commercial medium-power AC/DC source. At the outputs of both setups, we introduced filters with the aim of lowering the noise and to protect the following stages from high voltage spikes that can be generated by the energy stored in the cables after the release of accidental short circuits. Output noise is very low, as required: in the 100 MHz bandwidth the RMS level is about 37 μV(RMS) (CUORE setup) and 90 μV(RMS) (LUCIFER setup) at a load of 7 A, with a negligible dependence on the load current. Even more importantly, high frequency switching disturbances are almost completely suppressed. The efficiency of both systems is above 85%. Both systems are completely programmable and monitored via CAN bus (optically coupled). PMID:26724052

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

    PubMed Central

    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

  9. 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

  10. Thermionic triode generates ac power

    NASA Technical Reports Server (NTRS)

    Kniazzeh, A. G. F.; Scharz, F. C.

    1970-01-01

    Electrostatic grid controls conduction cycle of thermionic diode to convert low dc output voltages to high ac power without undesirable power loss. An ac voltage applied to the grid of this new thermionic triode enables it to convert heat directly into high voltage electrical power.

  11. AC/DC Power Systems with Applications for future Lunar/Mars base and Crew Exploration Vehicle

    NASA Technical Reports Server (NTRS)

    Chowdhury, Badrul H.

    2005-01-01

    ABSTRACT The Power Systems branch at JSC faces a number of complex issues as it readies itself for the President's initiative on future space exploration beyond low earth orbit. Some of these preliminary issues - those dealing with electric power generation and distribution on board Mars-bound vehicle and that on Lunar and Martian surface may be summarized as follows: Type of prime mover - Because solar power may not be readily available on parts of the Lunar/Mars surface and also during the long duration flight to Mars, the primary source of power will most likely be nuclear power (Uranium fuel rods) with a secondary source of fuel cell (Hydrogen supply). The electric power generation source - With nuclear power being the main prime mover, the electric power generation source will most likely be an ac generator at a yet to be determined frequency. Thus, a critical issue is whether the generator should generate at constant or variable frequency. This will decide what type of generator to use - whether it is a synchronous machine, an asynchronous induction machine or a switched reluctance machine. The type of power distribution system - the distribution frequency, number of wires (3- wire, 4-wire or higher), and ac/dc hybridization. Building redundancy and fault tolerance in the generation and distribution sub-systems so that the system is safe; provides 100% availability to critical loads; continues to operate even with faulted sub-systems; and requires minimal maintenance. This report descril_es results of a summer faculty fellowship spent in the Power Systems Branch with the specific aim of investigating some of the lessons learned in electric power generation and usage from the terrestrial power systems industry, the aerospace industry as well as NASA's on-going missions so as to recommend novel surface and vehicle-based power systems architectures in support of future space exploration initiatives. A hybrid ac/dc architecture with source side and load side

  12. Lowest of AC-DC power output for electrostrictive polymers energy harvesting systems

    NASA Astrophysics Data System (ADS)

    Meddad, Mounir; Eddiai, Adil; Hajjaji, Abdelowahed; Guyomar, Daniel; Belkhiat, Saad; Boughaleb, Yahia; Chérif, Aida

    2013-11-01

    Advances in technology led to the development of electronic circuits and sensors with extremely low electricity consumption. At the same time, structural health monitoring, technology and intelligent integrated systems created a need for wireless sensors in hard to reach places in aerospace vehicles and large civil engineering structures. Powering sensors with energy harvesters eliminates the need to replace batteries on a regular basis. Scientists have been forced to search for new power source that are able to harvested energy from their surrounding environment (sunlight, temperature gradients etc.). Electrostrictive polymer belonging to the family of electro-active polymers, offer unique properties for the electromechanical transducer technology has been of particular interest over the last few years in order to replace conventional techniques such as those based on piezoelectric or electromagnetic, these materials are highly attractive for their low-density, with large strain capability that can be as high as two orders of magnitude greater than the striction-limited, rigid and fragile electroactive ceramics. Electrostrictive polymers sensors respond to vibration with an ac output signal, one of the most important objectives of the electronic interface is to realize the required AC-DC conversion. The goal of this paper is to design an active, high efficiency power doubler converter for electrostrictive polymers exclusively uses a fraction of the harvested energy to supply its active devices. The simulation results show that it is possible to obtain a maximum efficiency of the AC-DC converter equal to 80%. Premiliminary experimental measurements were performed and the results obtained are in good agreement with simulations.

  13. Resonant AC power system proof-of-concept test program, volume 2, appendix 1

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This report contains two volumes. The main text (Volume 1) summarizes the tests results and gives a detailed discussion of the response of three early, first generation configurations of ac power system IRAD breadboards to the contracted tests imposed on them. It explains photographs, measurements, and data calculations, as well as any observed anomalies or lessons learned. This volume (No 2, Appendix 1, Test Results and Data), published under separate cover, includes all of the data taken on the 1.0 kW single-phase; 5.0 kW three-phase; and 25.0-kW three-phase system breadboards. The format of this data is raw, i.e., it is a direct copy of the data sheets for the test data notebook.

  14. Development of a single-phase harmonic power flow program to study the 20 kHz AC power system for large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan; Kankam, M. David

    1991-01-01

    The development of software is described to aid in design and analysis of AC power systems for large spacecraft. The algorithm is an important version of harmonic power flow program, HARMFLO, used for the study of AC power quality. The new program is applicable to three-phase systems typified by terrestrial power systems, and single-phase systems characteristic of space power systems. The modified HARMFLO accommodates system operating frequencies ranging from terrestrial 60 Hz to and beyond aerospace 20 kHz, and can handle both source and load-end harmonic distortions. Comparison of simulation and test results of a representative spacecraft power system shows a satisfactory correlation. Recommendations are made for the direction of future improvements to the software, to enhance its usefulness to power system designer and analysts.

  15. Semiconductor ac static power switch

    NASA Technical Reports Server (NTRS)

    Vrancik, J.

    1968-01-01

    Semiconductor ac static power switch has long life and high reliability, contains no moving parts, and operates satisfactorily in severe environments, including high vibration and shock conditions. Due to their resistance to shock and vibration, static switches are used where accidental switching caused by mechanical vibration or shock cannot be tolerated.

  16. Power conversion distribution system using a resonant high-frequency AC link

    NASA Technical Reports Server (NTRS)

    Sood, P. K.; Lipo, T. A.

    1986-01-01

    Static power conversion systems based on a resonant high frequency (HF) link offers a significant reduction in the size and weight of the equipment over that achieved with conventional approaches, especially when multiple sources and loads are to be integrated. A faster system response and absence of audible noise are the other principal characteristics of such systems. A conversion configuration based on a HF link which is suitable for applications requiring distributed power is proposed.

  17. AC power generation from microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Lobo, Fernanda Leite; Wang, Heming; Forrestal, Casey; Ren, Zhiyong Jason

    2015-11-01

    Microbial fuel cells (MFCs) directly convert biodegradable substrates to electricity and carry good potential for energy-positive wastewater treatment. However, the low and direct current (DC) output from MFC is not usable for general electronics except small sensors, yet commercial DC-AC converters or inverters used in solar systems cannot be directly applied to MFCs. This study presents a new DC-AC converter system for MFCs that can generate alternating voltage in any desired frequency. Results show that AC power can be easily achieved in three different frequencies tested (1, 10, 60 Hz), and no energy storage layer such as capacitors was needed. The DC-AC converter efficiency was higher than 95% when powered by either individual MFCs or simple MFC stacks. Total harmonic distortion (THD) was used to investigate the quality of the energy, and it showed that the energy could be directly usable for linear electronic loads. This study shows that through electrical conversion MFCs can be potentially used in household electronics for decentralized off-grid communities.

  18. Cooling Floor AC Systems

    NASA Astrophysics Data System (ADS)

    Jun, Lu; Hao, Ding; Hong, Zhang; Ce, Gao Dian

    The present HVAC equipments for the residential buildings in the Hot-summer-and-Cold-winter climate region are still at a high energy consuming level. So that the high efficiency HVAC system is an urgently need for achieving the preset government energy saving goal. With its advantage of highly sanitary, highly comfortable and uniform of temperature field, the hot-water resource floor radiation heating system has been widely accepted. This paper has put forward a new way in air-conditioning, which combines the fresh-air supply unit and such floor radiation system for the dehumidification and cooling in summer or heating in winter. By analyze its advantages and limitations, we found that this so called Cooling/ Heating Floor AC System can improve the IAQ of residential building while keep high efficiency quality. We also recommend a methodology for the HVAC system designing, which will ensure the reduction of energy cost of users.

  19. High-frequency ac power distribution in Space Station

    NASA Technical Reports Server (NTRS)

    Tsai, Fu-Sheng; Lee, Fred C. Y.

    1990-01-01

    A utility-type 20-kHz ac power distribution system for the Space Station, employing resonant power-conversion techniques, is presented. The system converts raw dc voltage from photovoltaic cells or three-phase LF ac voltage from a solar dynamic generator into a regulated 20-kHz ac voltage for distribution among various loads. The results of EASY5 computer simulations of the local and global performance show that the system has fast response and good transient behavior. The ac bus voltage is effectively regulated using the phase-control scheme, which is demonstrated with both line and load variations. The feasibility of paralleling the driver-module outputs is illustrated with the driver modules synchronized and sharing a common feedback loop. An HF sinusoidal ac voltage is generated in the three-phase ac input case, when the driver modules are phased 120 deg away from one another and their outputs are connected in series.

  20. Automated ac galvanomagnetic measurement system

    NASA Technical Reports Server (NTRS)

    Szofran, F. R.; Espy, P. N.

    1985-01-01

    An automated, ac galvanomagnetic measurement system is described. Hall or van der Pauw measurements in the temperature range 10-300 K can be made at a preselected magnetic field without operator attendance. Procedures to validate sample installation and correct operation of other system functions, such as magnetic field and thermometry, are included. Advantages of ac measurements are discussed.

  1. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  2. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  3. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  4. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  5. 21 CFR 886.4440 - AC-powered magnet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and...

  6. Power control for ac motor

    NASA Technical Reports Server (NTRS)

    Dabney, R. W. (Inventor)

    1984-01-01

    A motor controller employing a triac through which power is supplied to a motor is described. The open circuit voltage appearing across the triac controls the operation of a timing circuit. This timing circuit triggers on the triac at a time following turn off which varies inversely as a function of the amplitude of the open circuit voltage of the triac.

  7. ac propulsion system for an electric vehicle

    NASA Technical Reports Server (NTRS)

    Geppert, S.

    1980-01-01

    It is pointed out that dc drives will be the logical choice for current production electric vehicles (EV). However, by the mid-80's, there is a good chance that the price and reliability of suitable high-power semiconductors will allow for a competitive ac system. The driving force behind the ac approach is the induction motor, which has specific advantages relative to a dc shunt or series traction motor. These advantages would be an important factor in the case of a vehicle for which low maintenance characteristics are of primary importance. A description of an EV ac propulsion system is provided, taking into account the logic controller, the inverter, the motor, and a two-speed transmission-differential-axle assembly. The main barrier to the employment of the considered propulsion system in EV is not any technical problem, but inverter transistor cost.

  8. 21 CFR 886.1630 - AC-powered photostimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered photostimulator. 886.1630 Section 886.1630 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. An AC-powered photostimulator is an AC-powered device intended to provide light stimulus...

  9. 21 CFR 886.1630 - AC-powered photostimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered photostimulator. 886.1630 Section 886.1630 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Identification. An AC-powered photostimulator is an AC-powered device intended to provide light stimulus...

  10. Resistojet control and power for high frequency ac buses

    NASA Technical Reports Server (NTRS)

    Gruber, Robert P.

    1987-01-01

    Resistojets are operational on many geosynchronous communication satellites which all use dc power buses. Multipropellant resistojets were selected for the Initial Operating Capability (IOC) Space Station which will supply 208 V, 20 kHz power. This paper discusses resistojet heater temperature controllers and passive power regulation methods for ac power systems. A simple passive power regulation method suitable for use with regulated sinusoidal or square wave power was designed and tested using the Space Station multipropellant resistojet. The breadboard delivered 20 kHz power to the resistojet heater. Cold start surge current limiting, a power efficiency of 95 percent, and power regulation of better than 2 percent were demonstrated with a two component, 500 W breadboard power controller having a mass of 0.6 kg.

  11. Resistojet control and power for high frequency ac buses

    NASA Astrophysics Data System (ADS)

    Gruber, Robert P.

    Resistojets are operational on many geosynchronous communication satellites which all use dc power buses. Multipropellant resistojets were selected for the Initial Operating Capability (IOC) Space Station which will supply 208 V, 20 kHz power. This paper discusses resistojet heater temperature controllers and passive power regulation methods for ac power systems. A simple passive power regulation method suitable for use with regulated sinusoidal or square wave power was designed and tested using the Space Station multipropellant resistojet. The breadboard delivered 20 kHz power to the resistojet heater. Cold start surge current limiting, a power efficiency of 95 percent, and power regulation of better than 2 percent were demonstrated with a two component, 500 W breadboard power controller having a mass of 0.6 kg.

  12. Resistojet control and power for high frequency ac buses

    NASA Astrophysics Data System (ADS)

    Gruber, Robert P.

    1987-05-01

    Resistojets are operational on many geosynchronous communication satellites which all use dc power buses. Multipropellant resistojets were selected for the Initial Operating Capability (IOC) Space Station which will supply 208 V, 20 kHz power. This paper discusses resistojet heater temperature controllers and passive power regulation methods for ac power systems. A simple passive power regulation method suitable for use with regulated sinusoidal or square wave power was designed and tested using the Space Station multipropellant resistojet. The breadboard delivered 20 kHz power to the resistojet heater. Cold start surge current limiting, a power efficiency of 95 percent, and power regulation of better than 2 percent were demonstrated with a two component, 500 W breadboard power controller having a mass of 0.6 kg.

  13. Three-phase ac-to-ac series-resonant power converter with a reduced number of thyristors

    SciTech Connect

    Klaassens, J.B.; de Beer, F. )

    1991-07-01

    This paper reports that ac-ac series-resonant converters have been proven to be functional and useful. Power pulse modulation with internal frequencies of tens of kHz and suited for multikilowatt power levels is applied to a series-resonant converter system for generating synthesized multiphase bipolar waveforms with reversible power flow and flow distortion. The use of a series-resonant circuit for power transfer and control obtains natural current commutation of the thyristors and the prevention of excessive stresses on components. Switches are required which have bidirectional current conduction and voltage blocking ability. The conventional series-resonant ac-ac converter applies a total for 24 anti-parallel thyristors. An alternative circuit configuration for the series-resonant ac-ac converter with only 12 thyristors is also presented. The alternative power circuit has three neutrals, related to the polyphase source, the load and the converter, which may be interconnected. If they are connected, the high-frequency component of the source and load currents will flow through the connection between the neutrals. The test results of a converter system generating three-phase sinusoidal input and output waveforms have demonstrated the significant aspects of this type of power interfaces.

  14. Power Electronic Transformer based Three-Phase PWM AC Drives

    NASA Astrophysics Data System (ADS)

    Basu, Kaushik

    A Transformer is used to provide galvanic isolation and to connect systems at different voltage levels. It is one of the largest and most expensive component in most of the high voltage and high power systems. Its size is inversely proportional to the operating frequency. The central idea behind a power electronic transformer (PET) also known as solid state transformer is to reduce the size of the transformer by increasing the frequency. Power electronic converters are used to change the frequency of operation. Steady reduction in the cost of the semiconductor switches and the advent of advanced magnetic materials with very low loss density and high saturation flux density implies economic viability and feasibility of a design with high power density. Application of PET is in generation of power from renewable energy sources, especially wind and solar. Other important application include grid tied inverters, UPS e.t.c. In this thesis non-resonant, single stage, bi-directional PET is considered. The main objective of this converter is to generate adjustable speed and magnitude pulse width modulated (PWM) ac waveforms from an ac or dc grid with a high frequency ac link. The windings of a high frequency transformer contains leakage inductance. Any switching transition of the power electronic converter connecting the inductive load and the transformer requires commutation of leakage energy. Commutation by passive means results in power loss, decrease in the frequency of operation, distortion in the output voltage waveform, reduction in reliability and power density. In this work a source based partially loss-less commutation of leakage energy has been proposed. This technique also results in partial soft-switching. A series of converters with novel PWM strategies have been proposed to minimize the frequency of leakage inductance commutation. These PETs achieve most of the important features of modern PWM ac drives including 1) Input power factor correction, 2) Common

  15. Programmable AC power supply for simulating power transient expected in fusion reactor

    SciTech Connect

    Halimi, B.; Suh, K. Y.

    2012-07-01

    This paper focus on control engineering of the programmable AC power source which has capability to simulate power transient expected in fusion reactor. To generate the programmable power source, AC-AC power electronics converter is adopted to control the power of a set of heaters to represent the transient phenomena of heat exchangers or heat sources of a fusion reactor. The International Thermonuclear Experimental Reactor (ITER) plasma operation scenario is used as the basic reference for producing this transient power source. (authors)

  16. Electrical power generating system

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1983-01-01

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

  17. Development of an AC Module System: Final Technical Report

    SciTech Connect

    Suparna Kadam; Miles Russell

    2012-06-15

    The GreenRay Inc. program focused on simplifying solar electricity and making it affordable and accessible to the mainstream population. This was accomplished by integrating a solar module, micro-inverter, mounting and monitoring into a reliable, 'plug and play' AC system for residential rooftops, offering the following advantages: (1) Reduced Cost: Reduction in installation labor with fewer components, faster mounting, faster wiring. (2) Maximized Energy Production: Each AC Module operates at its maximum, reducing overall losses from shading, mismatch, or module downtime. (3) Increased Safety. Electrical and fire safety experts agree that AC Modules have significant benefits, with no energized wiring or live connections during installation, maintenance or emergency conditions. (4) Simplified PV for a Broader Group of Installers. Dramatic simplification of design and installation of a solar power system, enabling faster and more efficient delivery of the product into the market through well-established, mainstream channels. This makes solar more accessible to the public. (5) Broadened the Rooftop Market: AC Modules enable solar for many homes that have shading, split roofs, or obstructions. In addition, due to the smaller building block size of 200W vs. 1000W, homeowners with budget limitations can start small and add to their systems over time. Through this DOE program GreenRay developed the all-in-one AC Module system with an integrated PV Module and microinverter, custom residential mounting and performance monitoring. Development efforts took the product from its initial concept, through prototypes, to a commercial product sold and deployed in the residential market. This pilot deployment has demonstrated the technical effectiveness of the AC Module system in meeting the needs and solving the problems of the residential market. While more expensive than the traditional central inverter systems at the pilot scale, the economics of AC Modules become more and more

  18. High-power ac/dc variable load simulator

    NASA Technical Reports Server (NTRS)

    Joncas, K. P.; Birnbach, S.; Bruce, L. D.; Smith, L.

    1975-01-01

    Design of medium-power dynamic electrical load simulator has been extended to permit simulation of ac as well as dc loads and to provide for operation at higher power levels. Simulator is internally protected against reverse voltage, overvoltage, overcurrent, and overload conditions.

  19. Development of software to improve AC power quality on large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan

    1991-01-01

    To insure the reliability of a 20 kHz, alternating current (AC) power system on spacecraft, it is essential to analyze its behavior under many adverse operating conditions. Some of these conditions include overloads, short circuits, switching surges, and harmonic distortions. Harmonic distortions can become a serious problem. It can cause malfunctions in equipment that the power system is supplying, and, during distortions such as voltage resonance, it can cause equipment and insulation failures due to the extreme peak voltages. To address the harmonic distortion issue, work was begun under the 1990 NASA-ASEE Summer Faculty Fellowship Program. Software, originally developed by EPRI, called HARMFLO, a power flow program capable of analyzing harmonic conditions on three phase, balanced, 60 Hz AC power systems, was modified to analyze single phase, 20 kHz, AC power systems. Since almost all of the equipment used on spacecraft power systems is electrically different from equipment used on terrestrial power systems, it was also necessary to develop mathematical models for the equipment to be used on the spacecraft. The modelling was also started under the same fellowship work period. Details of the modifications and models completed during the 1990 NASA-ASEE Summer Faculty Fellowship Program can be found in a project report. As a continuation of the work to develop a complete package necessary for the full analysis of spacecraft AC power system behavior, deployment work has continued through NASA Grant NAG3-1254. This report details the work covered by the above mentioned grant.

  20. 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.

  1. AC propulsion system for an electric vehicle, phase 2

    NASA Technical Reports Server (NTRS)

    Slicker, J. M.

    1983-01-01

    A second-generation prototype ac propulsion system for a passenger electric vehicle was designed, fabricated, tested, installed in a modified Mercury Lynx vehicle and track tested at the Contractor's site. The system consisted of a Phase 2, 18.7 kw rated ac induction traction motor, a 192-volt, battery powered, pulse-width-modulated, transistorized inverter packaged for under rear seat installation, a 2-axis, 2-speed, automatically-shifted mechanical transaxle and a microprocessor-based powertrain/vehicle controller. A diagnostics computer to assist tuning and fault finding was fabricated. Dc-to-mechanical-system efficiency varied from 78% to 82% as axle speed/torque ranged from 159 rpm/788 nm to 65 rpm/328 nm. Track test efficiency results suggest that the ac system will be equal or superior to dc systems when driving urban cycles. Additional short-term work is being performed under a third contract phase (AC-3) to raise transaxle efficiency to predicted levels, and to improve starting and shifting characteristics. However, the long-term challenge to the system's viability remains inverter cost. A final report on the Phase 2 system, describing Phase 3 modifications, will be issued at the conclusion of AC-3.

  2. AC propulsion system for an electric vehicle, phase 2

    NASA Astrophysics Data System (ADS)

    Slicker, J. M.

    1983-06-01

    A second-generation prototype ac propulsion system for a passenger electric vehicle was designed, fabricated, tested, installed in a modified Mercury Lynx vehicle and track tested at the Contractor's site. The system consisted of a Phase 2, 18.7 kw rated ac induction traction motor, a 192-volt, battery powered, pulse-width-modulated, transistorized inverter packaged for under rear seat installation, a 2-axis, 2-speed, automatically-shifted mechanical transaxle and a microprocessor-based powertrain/vehicle controller. A diagnostics computer to assist tuning and fault finding was fabricated. Dc-to-mechanical-system efficiency varied from 78% to 82% as axle speed/torque ranged from 159 rpm/788 nm to 65 rpm/328 nm. Track test efficiency results suggest that the ac system will be equal or superior to dc systems when driving urban cycles. Additional short-term work is being performed under a third contract phase (AC-3) to raise transaxle efficiency to predicted levels, and to improve starting and shifting characteristics. However, the long-term challenge to the system's viability remains inverter cost. A final report on the Phase 2 system, describing Phase 3 modifications, will be issued at the conclusion of AC-3.

  3. Save power in AC induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J.

    1977-01-01

    Relatively simple and inexpensive circuitry improves power factor and reduces power dissipation in induction motors operating below full load. Electronic control loop conserves energy by reducing voltage applied to lightly loaded motor. Circuit forces motor to run at constant predetermined optimum power factor, regardless of load or line voltage variations. Solid-state switch varies voltage.

  4. Control of multiterminal HVDC systems embedded in AC networks. Volume 1. Methodologies for control system design

    NASA Astrophysics Data System (ADS)

    Hauth, R. L.; Nozari, F.; Winkelman, J. R.; Athans, M.; Chan, S. M.

    1982-05-01

    Control concepts applicable to future multiterminal high voltage dc (MTDC) networks embedded in bulk power ac systems are discussed. The control's objectives are to enhance the steady state and/or dynamic performance of the integrated MTDC/ac power system. A multi-terminal HVdc system is one with more than two converter terminals. The three basic control levels of an MTDC system are: primary control, supplementary power modulation (damping) controls, and dispatch control. Techniques for use in all three levels of control are described. The application of modern control robustness theories to the MTDC power modulation control design methodology is discussed.

  5. Introducing AC inductive reactance with a power tool

    NASA Astrophysics Data System (ADS)

    Bryant, Wesley; Baker, Blane

    2016-09-01

    The concept of reactance in AC electrical circuits is often non-intuitive and difficult for students to grasp. In order to address this lack of conceptual understanding, classroom exercises compare the predicted resistance of a power tool, based on electrical specifications, to measured resistance. Once students discover that measured resistance is smaller than expected, they are asked to explain these observations using previously studied principles of magnetic induction. Exercises also introduce the notion of inductive reactance and impedance in AC circuits and, ultimately, determine self-inductance of the motor windings within the power tool.

  6. Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

    NASA Technical Reports Server (NTRS)

    Peak, S. C.

    1982-01-01

    An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

  7. Coupling an induction motor type generator to ac power lines. [making windmill generators compatible with public power lines

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A system for coupling an induction motor type generator to an A.C. power line includes an electronic switch means that is controlled by a control system and is regulated to turn on at a relatively late point in each half cycle of its operation. The energizing power supplied by the line to the induction motor type generator is decreased and the net power delivered to the line is increased.

  8. Introducing AC Inductive Reactance with a Power Tool

    ERIC Educational Resources Information Center

    Bryant, Wesley; Baker, Blane

    2016-01-01

    The concept of reactance in AC electrical circuits is often non-intuitive and difficult for students to grasp. In order to address this lack of conceptual understanding, classroom exercises compare the predicted resistance of a power tool, based on electrical specifications, to measured resistance. Once students discover that measured resistance…

  9. Watts Up? Pro AC Power Meter for Automated Energy Recording

    PubMed Central

    Hirst, Jason M.; Miller, Jonathan R.; Kaplan, Brent A.; Reed, Derek D.

    2013-01-01

    The purpose of the present paper is to review the Watts up? Pro AC power meter. Evaluations of the meter's reliability for measuring energy consumption by consumer electronics yielded acceptable levels of reliability. Implications and limitations for the use of this product in behavior analytic research and practice are discussed.

  10. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered slitlamp biomicroscope. 886.1850 Section 886.1850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... a thin, intense beam of light. (b) Classification. Class II....

  11. 21 CFR 886.1850 - AC-powered slitlamp biomicroscope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered slitlamp biomicroscope. 886.1850 Section 886.1850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... microscope intended for use in eye examination that projects into a patient's eye through a control...

  12. ac power control in the Core Flow Test Loop

    SciTech Connect

    McDonald, D.W.

    1980-01-01

    This work represents a status report on a development effort to design an ac power controller for the Core Flow Test Loop. The Core Flow Test Loop will be an engineering test facility which will simulate the thermal environment of a gas-cooled fast-breeder reactor. The problems and limitations of using sinusoidal ac power to simulate the power generated within a nuclear reactor are addressed. The transformer-thyristor configuration chosen for the Core Flow Test Loop power supply is presented. The initial considerations, design, and analysis of a closed-loop controller prototype are detailed. The design is then analyzed for improved performance possibilities and failure modes are investigated at length. A summary of the work completed to date and a proposed outline for continued development completes the report.

  13. Development of a 10 kW High Temperature High Power Density Three-Phase AC-DC-AC SiC Converter

    SciTech Connect

    Ning, Puqi

    2012-01-01

    This paper presents the development and experimental performance of a 10 kW, all SiC, 250 C junction temperature high-power-density three-phase ac-dc-ac converter. The electromagnetic interference filter, thermal system, high temperature package, and gate drive design are discussed in detail. Finally, tests confirming the feasibility and validating the theoretical basis of the prototype converter system are described.

  14. Development of software to improve AC power quality on large spacecraft

    NASA Technical Reports Server (NTRS)

    Kraft, L. Alan

    1991-01-01

    To insure the reliability of a 20 kHz, AC power system on spacecraft, it is essential to analyze its behavior under many adverse operating conditions. Some of these conditions include overloads, short circuits, switching surges, and harmonic distortions. Harmonic distortions can cause malfunctions in equipment that the power system is supplying, and during extreme distortions such as voltage resonance, it can cause equipment and insulation failures due to the extreme peak voltages. HARMFLO, a power flow computer program, which was capable of analyzing harmonic conditions on three phase, balanced, 60 Hz, AC power systems, was modified to analyze single phase, 20 kHz, AC power systems. Since almost all of the equipment used on spacecraft power systems is electrically different from equipment used on terrestrial power systems, it was also necessary to develop mathematical models for the equipment to be used on the spacecraft. The results are that (1) the harmonic power now has a model of a single phase, voltage controlled, full wave rectifier; and (2) HARMFLO was ported to the SUN workstation platform.

  15. Power system

    DOEpatents

    Hickam, Christopher Dale

    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.

  16. UPS with input commutation between ac and dc sources of power

    SciTech Connect

    Severinsky, A.J.

    1993-08-31

    An uninterruptible power supply is described, said power supply comprising: AC input terminal means for receiving a first AC voltage from an AC power source; DC input terminal means for receiving a first DC voltage from a DC power source; AC output terminal means for connecting to a load; converter means for converting said first AC voltage to a second DC voltage across electrical charge storage means coupled to said converter means, said second DC voltage being larger than the maximum peak voltage of said first AC voltage and said first DC voltage; switching means coupled to said AC power source and said DC power source for selectively connecting said AC power source or said DC power source to said converter means; inverter means coupled to said electrical charge storage means for receiving said second DC voltage and inverting said second DC voltage to a second AC voltage, said second AC voltage being coupled to said AC output terminal means; and control means coupled to said switching means for controlling the operation of said switching means, said control means operating said switching means to connect said AC power source to said converter means only when said first AC voltage is within a predetermined range and operating to connect said DC power source to said converter means when said first AC voltage is outside of said range.

  17. AC magnetic susceptibility of Bi2223-system

    NASA Astrophysics Data System (ADS)

    Kimishima, Y.; Inagaki, K.; Tanabe, K.; Nagata, N.; Ichiyanagi, Y.

    1998-01-01

    The AC magnetic susceptibilities χ AC of a Bi2223 sintered sample were measured by the Hartshorn bridge method. The linear AC χ' 0 showed the two-steps behavior at T C1 and T C2, where T C1 > T C2. The χ'0-data between T C1 and T C2 has no H AC-dependence and agreed well with those of powder specimen, and they can be regarded as the intragrain magnetic susceptibility. Below the inter-grain transition temperature T C2 the χ″ 0 showed a positive peak. The temperature dependence of χ' 0 and χ″ 0 were analyzed by the Bean's critical-state model. As a result, the temperature dependence of critical current density J C ∝ (1 - T/T C2) β was obtained with β = 2.3-2.6. The non-linear χ' 2 and χ″ 2 below T C2 resemble the behaviors derived from the Bean model, but the negative divergence of χ' 2 may show the evidence of d-wave paring in the present Bi2223-system.

  18. AC Josephson effect applications in microwave systems

    NASA Astrophysics Data System (ADS)

    Larkin, Serguey Y.

    1996-12-01

    A complication of the tasks solving by the modem radliolocation, radionavigation and communication systems connected with the demand promotion to the resolution and accuracy of coordinates definition and increase in the volumes of transmitted information in satellite communication systems has resulted in boisterous mastering of millimeter wave bands. Success in microwave technology reached in 80' allowed such leading instrument developing companies as Hewlett Packard; EIP, lB millimeter etc. to set up an output of mm- and submm-wave bands devices and systems. It has streamlined Scientific Technological Progress in several spheres, since millimeter, through infra-red frequency range was closed to researchers for a long period of time because of the absence of necessary equipment. At present microwave devices of the short-wave part of mm- wave band and of submm- wave bands are used not only in radiolocation and communications. Unique diagnostic systems based on the analysis of the radiation parameters of different microwave sources were created. They have their application in medicine, thermonuclear energetics, radioastronomy, biology, nuclear physics, the physics of the solid state body, geology, etc. The above circumstances caused the beginning of the measuring microwave technology researches in 60 to 600 GHz frequency range: generators, power and frequency meters, spectrum analyzers. The task of working out equipment and techniques of the effective control as well as frequency and intensity measurements of the microwave signals in the investigated range is of the special interest. Here are some examples. The creation of a thermonuclear reactor in ITER project is considered to be the project of the century in the energetics sphere. One of the basic engineering tasks in the course of project realization is the creation of the diagnostic equipment realizing in real time spectrum analysis of thermonuclear plasma radiation at the so called cyclotron hannonics. Such

  19. Improved transistorized ac motor controller for battery powered urban electric passenger vehicles

    SciTech Connect

    Peak, S.C.

    1982-09-01

    The objectives of this program for an improved ac motor controller for battery powered urban electric passenger vehicles were: the design, fabrication, test, evaluation and cost analysis of an engineering model controller for an ac induction motor drive system, the investigation of a power level expansion to a family of horsepower and battery system voltages, and the investigation of the applicability of the ac controller for use as an on-board battery charger and for providing the function of motor reversal. Additional vehicle specifications, e.g., acceleration and pulling out of potholes, were added to the NASA vehicle specifications. Then, a vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The General Electric ac induction motor used in the drive is optimized to operate as a vehicle traction motor with a pulse width modulated (PWM) inverter as a power source. The motor is nominally rated 20 hp and 41 hp peak. The power inverter design is a three-phase transistorized bridge configuration with feedback diodes. The transistors are a special design General Electric high-power Darlington transistor rated 450 volts and 200 amps. The battery system voltage chosen was 108 volts. The control strategy is a constant torque profile by PWM operation to base speed and a constant horsepower profile by square-wave operation to maximum speed. A gear shifting transmission is not required. An advanced current-controlled PWM technique is used to control the motor voltage. The primary feedback control is a motor angle control, with voltage and torque outer loop controls.

  20. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false AC-powered adjustable hospital bed. 880.5100... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered... electric motor and remote controls that can be operated by the patient to adjust the height and...

  1. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false AC-powered adjustable hospital bed. 880.5100... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered... electric motor and remote controls that can be operated by the patient to adjust the height and...

  2. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered adjustable hospital bed. 880.5100... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered... electric motor and remote controls that can be operated by the patient to adjust the height and...

  3. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered adjustable hospital bed. 880.5100... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered... electric motor and remote controls that can be operated by the patient to adjust the height and...

  4. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false AC-powered medical examination light. 880.6320 Section 880.6320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Miscellaneous Devices § 880.6320 AC-powered medical examination light. (a) Identification. An AC-powered...

  5. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered medical examination light. 880.6320 Section 880.6320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Miscellaneous Devices § 880.6320 AC-powered medical examination light. (a) Identification. An AC-powered...

  6. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false AC-powered medical examination light. 880.6320 Section 880.6320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Miscellaneous Devices § 880.6320 AC-powered medical examination light. (a) Identification. An AC-powered...

  7. 33. A.C. PANEL FOR MENTONE POWER HOUSE, P.L. & P. ...

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

    33. A.C. PANEL FOR MENTONE POWER HOUSE, P.L. & P. CO., LOS ANGELES. RETRACED FROM MASSON'S DRAWING NO. C-275. JAN. 20, 1909. SCE drawing no. 52880. - Santa Ana River Hydroelectric System, SAR-3 Powerhouse, San Bernardino National Forest, Redlands, San Bernardino County, CA

  8. Design and Analysis of the Main AC/DC Converter System for ITER

    NASA Astrophysics Data System (ADS)

    Sheng, Zhicai; Xu, Liuwei; Fu, Peng

    2012-04-01

    A design of the main AC/DC converter system for ITER is described and the configuration of the main AC/DC converters is presented. To reduce the reactive power absorbed from the converter units, the main AC/DC converters are designed to be series-connected and work in a sequential mode. The structure of the regulator of the converter system is described. A simulation model was built up for the PSCAD/EMTDC code, and the design was validated accordingly. Harmonic analysis and reactive power calculation of the converters units are presented. The results reveal the advantage of sequential control in reducing reactive power and harmonics.

  9. Direct current power delivery system and method

    DOEpatents

    Zhang, Di; Garces, Luis Jose; Dai, Jian; Lai, Rixin

    2016-09-06

    A power transmission system includes a first unit for carrying out the steps of receiving high voltage direct current (HVDC) power from an HVDC power line, generating an alternating current (AC) component indicative of a status of the first unit, and adding the AC component to the HVDC power line. Further, the power transmission system includes a second unit for carrying out the steps of generating a direct current (DC) voltage to transfer the HVDC power on the HVDC power line, wherein the HVDC power line is coupled between the first unit and the second unit, detecting a presence or an absence of the added AC component in the HVDC power line, and determining the status of the first unit based on the added AC component.

  10. Electrical power system WP-04

    NASA Technical Reports Server (NTRS)

    Nored, Donald L.

    1990-01-01

    Viewgraphs on Space Station Freedom Electrical Power System (EPS) WP-40 are presented. Topics covered include: key EPS technical requirements; photovoltaic power module systems; solar array assembly; blanket containment box and box positioning subassemblies; solar cell; bypass diode assembly; Kapton with atomic oxygen resistant coating; sequential shunt unit; gimbal assembly; energy storage subsystem; thermal control subsystem; direct current switching unit; integrated equipment assembly; PV cargo element; PMAD system; and PMC and AC architecture.

  11. A novel wireless power and data transmission AC to DC converter for an implantable device.

    PubMed

    Liu, Jhao-Yan; Tang, Kea-Tiong

    2013-01-01

    This article presents a novel AC to DC converter implemented by standard CMOS technology, applied for wireless power transmission. This circuit combines the functions of the rectifier and DC to DC converter, rather than using the rectifier to convert AC to DC and then supplying the required voltage with regulator as in the transitional method. This modification can reduce the power consumption and the area of the circuit. This circuit also transfers the loading condition back to the external circuit by the load shift keying(LSK), determining if the input power is not enough or excessive, which increases the efficiency of the total system. The AC to DC converter is fabricated with the TSMC 90nm CMOS process. The circuit area is 0.071mm(2). The circuit can produce a 1V DC voltage with maximum output current of 10mA from an AC input ranging from 1.5V to 2V, at 1MHz to 10MHz. PMID:24110077

  12. Combined Operation of AC and DC Distribution System with Distributed Generation Units

    NASA Astrophysics Data System (ADS)

    Noroozian, Reza; Abedi, Mehrdad; Gharehpetian, Gevorg

    2010-07-01

    This paper presents a DC distribution system which has been supplied by external AC systems as well as local DG units in order to demonstrate an overall solution to power quality issue. In this paper, the proposed operation method is demonstrated by simulation of power transfer between external AC systems, DG units, AC and DC loads. The power flow control in DC distribution system has been achieved by network converters and DG converters. Also, the mathematical model of the network, DG and load converters are obtained by using the average technique, which allows converter systems accurately simulated and control strategies for this converters is achieved. A suitable control strategy for network converters has been proposed that involves DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control technique has been proposed for DG converters. In this paper, a novel control system based on stationary and synchronously rotating reference frame has been proposed for load converters for supplying AC loads connected to the DC bus by balanced voltages. The several case studies have been studied based on proposed methods. The simulation results show that DC distribution systems including DG units can improve the power quality at the point of common coupling (PCC) in the power distribution system or industrial power system.

  13. New levitation scheme with AC superconducting magnet for EDS MAGLEV system

    SciTech Connect

    Kim, D.H.; Lee, J.K.; Hahn, S.Y.; Cha, G.

    1996-09-01

    This paper proposes a new magnetic levitation scheme which is able to generate levitation force for all speeds including a standstill. Auxiliary wheels which are needed in EDS MAGLEV vehicle can be eliminated. This scheme uses AC superconducting magnets to generate levitation force. In this paper, magnetic fields, forces and power dissipations generated by AC magnets moving above a conducting slab are calculated analytically. Results of calculation show characteristics of EDS system with AC magnet, such as levitation force and loss, are superior to those of EDS system with DC magnets for all speeds.

  14. Improved SCR ac Motor Controller for Battery Powered Urban Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Latos, T. S.

    1982-01-01

    An improved ac motor controller, which when coupled to a standard ac induction motor and a dc propulsion battery would provide a complete electric vehicle power train with the exception of the mechanical transmission and drive wheels was designed. In such a system, the motor controller converts the dc electrical power available at the battery terminals to ac electrical power for the induction motor in response to the drivers commands. The performance requirements of a hypothetical electric vehicle with an upper weight bound of 1590 kg (3500 lb) were used to determine the power rating of the controller. Vehicle acceleration capability, top speed, and gradeability requisites were contained in the Society of Automotive Engineers (SAE) Schedule 227a(d) driving cycle. The important capabilities contained in this driving cycle are a vehicle acceleration requirement of 0 to 72.4 kmph (0 to 45 mph) in 28 seconds a top speed of 88.5 kmph (55 mph), and the ability to negotiate a 10% grade at 48 kmph (30 mph). A 10% grade is defined as one foot of vertical rise per 10 feet of horizontal distance.

  15. Low-energy hydraulic fracturing wastewater treatment via AC powered electrocoagulation with biochar.

    PubMed

    Lobo, Fernanda Leite; Wang, Heming; Huggins, Tyler; Rosenblum, James; Linden, Karl G; Ren, Zhiyong Jason

    2016-05-15

    Produced and flowback waters are the largest byproducts associated with unconventional oil and gas exploration and production. Sustainable and low cost technologies are needed to treat and reuse this wastewater to avoid the environmental problems associated with current management practices (i.e., deep well injection). This study presents a new process to integrate AC-powered electrocoagulation (EC) with granular biochar to dramatically reduce energy use and electrode passivation while achieving high treatment efficiency. Results show achieving a 99% turbidity and TSS removal for the AC-EC-biochar system only used 0.079 kWh/m(3) or 0.15 kWh/kg TSS, which is 70% lower than traditional DC-EC systems and orders of magnitude lower than previous studies. The amount of biochar added positively correlates with energy saving, and further studies are needed to improve organic carbon and salt removal through system integration. PMID:26894291

  16. Preliminary study of AC power feeders for AGS booster

    SciTech Connect

    Meth, M.

    1992-07-17

    It has been proposed that the AGS Heavy Ion/Proton Booster be excited directly from the electric power distribution system without intervening an energy storage buffer such as an MG set or a magnetic energy buffer. The average power requirement of the AGS Booster is less than many single-loads presently housed on the lab site. However, the power swing will be the largest single pulsating load on the lab site. The large power swings will impact on the power grid producing utility-line disturbances such as voltage fluctuations and harmonic generation. Thus, it is necessary to carefully evaluate the quality of the electric power system resulting from the interconnection, such that the utility system is not degraded either on the lab site or at LILCO`s substation.

  17. Preliminary study of AC power feeders for AGS booster

    SciTech Connect

    Meth, M.

    1992-07-17

    It has been proposed that the AGS Heavy Ion/Proton Booster be excited directly from the electric power distribution system without intervening an energy storage buffer such as an MG set or a magnetic energy buffer. The average power requirement of the AGS Booster is less than many single-loads presently housed on the lab site. However, the power swing will be the largest single pulsating load on the lab site. The large power swings will impact on the power grid producing utility-line disturbances such as voltage fluctuations and harmonic generation. Thus, it is necessary to carefully evaluate the quality of the electric power system resulting from the interconnection, such that the utility system is not degraded either on the lab site or at LILCO's substation.

  18. ESBWR response to an extended station blackout/loss of all AC power

    SciTech Connect

    Barrett, A. J.; Marquino, W.

    2012-07-01

    U.S. federal regulations require light water cooled nuclear power plants to cope with Station Blackouts for a predetermined amount of time based on design factors for the plant. U.S. regulations define Station Blackout (SBO) as a loss of the offsite electric power system concurrent with turbine trip and unavailability of the onsite emergency AC power system. According to U.S. regulations, typically the coping period for an SBO is 4 hours and can be as long as 16 hours for currently operating BWR plants. Being able to cope with an SBO and loss of all AC power is required by international regulators as well. The U.S. licensing basis for the ESBWR is a coping period of 72 hours for an SBO based on U.S. NRC requirements for passive safety plants. In the event of an extended SBO (viz., greater than 72 hours), the ESBWR response shows that the design is able to cope with the event for at least 7 days without AC electrical power or operator action. ESBWR is a Generation III+ reactor design with an array of passive safety systems. The ESBWR primary success path for mitigation of an SBO event is the Isolation Condenser System (ICS). The ICS is a passive, closed loop, safety system that initiates automatically on a loss of power. Upon Station Blackout or loss of all AC power, the ICS begins removing decay heat from the Reactor Pressure Vessel (RPV) by (i) condensing the steam into water in heat exchangers located in pools of water above the containment, and (ii) transferring the decay heat to the atmosphere. The condensed water is then returned by gravity to cool the reactor again. The ICS alone is capable of maintaining the ESBWR in a safe shutdown condition after an SBO for an extended period. The fuel remains covered throughout the SBO event. The ICS is able to remove decay heat from the RPV for at least 7 days and maintains the reactor in a safe shutdown condition. The water level in the RPV remains well above the top of active fuel for the duration of the SBO event

  19. Control Structures for VSC-based FACTS Devices under Normal and Faulted AC-systems

    NASA Astrophysics Data System (ADS)

    Babaei, Saman

    This thesis is concerned with improving the Flexible AC Transmission Systems (FACTS) devices performance under the normal and fault AC-system conditions by proposing new control structures and also converter topologies. The combination of the increasing electricity demand and restrictions in expanding the power system infrastructures has urged the utility owners to deploy the utility-scaled power electronics in the power system. Basically, FACTS is referred to the application of the power electronics in the power systems. Voltage Source Converter (VSC) is the preferred building block of the FACTS devices and many other utility-scale power electronics applications. Despite of advances in the semiconductor technology and ultra-fast microprocessor based controllers, there are still many issues to address and room to improve[25]. An attempt is made in this thesis to address these important issues of the VSC-based FACTS devices and provide solutions to improve them.

  20. Fuzzy based power factor improvement strategy for a multiple connected AC-DC converter fed drive

    NASA Astrophysics Data System (ADS)

    Radhakrishnan, N.; Muthiah, Ramaswamy

    2012-01-01

    The main focus of this paper is to design a Fuzzy based control algorithm to realize an improvement in the input power factor of a multiple connected AC-DC converter fed drive system. It incorporates the role of fuzzy inference principles to generate appropriate PWM pulses for the power switches at the second stage of the power module. The philosophy is developed, with a view to reshape the input current phasor and enables it to align with the supply voltage wave in the perspective of improving the input power factor. The closed loop scheme evaluated using MATLAB based simulation exhibits an enhancement in supply power factor over a range of operating loads in addition to illustrating the speed regulating capability of the drive.

  1. An AC drive system for a battery driven moped

    SciTech Connect

    Nandi, S.; Saha, S.; Sharon, M.; Sundersingh, V.P.

    1995-12-31

    A petrol driven moped is converted to an electric one by replacing the petrol engine by a three phase 1.5 HR, AC squirrel cage induction motor drive system. The motor voltage rating selected is 200 V to keep the DC boost voltage level to a reasonable value.f the power source used is a high energy density, 24 V, 110 Ah, Ni-Zn battery. A modified indirect current controlled step-up chopper as well as a standard push-pull DC-DC boost converter is studied for the boost scheme. A simple three phase quasi-square wave inverter is designed along with suitable protection for driving the motor. Successful trial test of the system has been conducted at the laboratory.

  2. 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.

  3. Electrostatic coalescence system with independent AC and DC hydrophilic electrodes

    DOEpatents

    Hovarongkura, A. David; Henry, Jr., Joseph D.

    1981-01-01

    An improved electrostatic coalescence system is provided in which independent AC and DC hydrophilic electrodes are employed to provide more complete dehydration of an oil emulsion. The AC field is produced between an AC electrode array and the water-oil interface wherein the AC electrode array is positioned parallel to the interface which acts as a grounded electrode. The emulsion is introduced into the AC field in an evenly distributed manner at the interface. The AC field promotes drop-drop and drop-interface coalescence of the water phase in the entering emulsion. The continuous oil phase passes upward through the perforated AC electrode array and enters a strong DC field produced between closely spaced DC electrodes in which small dispersed droplets of water entrained in the continuous phase are removed primarily by collection at hydrophilic DC electrodes. Large droplets of water collected by the electrodes migrate downward through the AC electrode array to the interface. All phase separation mechanisms are utilized to accomplish more complete phase separation.

  4. Direct current uninterruptible power supply method and system

    DOEpatents

    Sinha, Gautam

    2003-12-02

    A method and system are described for providing a direct current (DC) uninterruptible power supply with the method including, for example: continuously supplying fuel to a turbine; converting mechanical power from the turbine into alternating current (AC) electrical power; converting the AC electrical power to DC power within a predetermined voltage level range; supplying the DC power to a load; and maintaining a DC load voltage within the predetermined voltage level range by adjusting the amount of fuel supplied to the turbine.

  5. A comparative study of electric power distribution systems for spacecraft

    NASA Technical Reports Server (NTRS)

    Stuart, Thomas A.; King, Roger J.

    1990-01-01

    The electric power distribution systems for spacecraft are compared concentrating on two interrelated issues: the choice between dc and high frequency ac, and the converter/inverter topology to be used at the power source. The relative merits of dc and ac distribution are discussed. Specific converter and inverter topologies are identified and analyzed in detail for the purpose of detailed comparison. Finally, specific topologies are recommended for use in dc and ac systems.

  6. HVDC-AC system interaction from AC harmonics. Volume 1. Harmonic impedance calculations. Final report

    SciTech Connect

    Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W; Turner, A E; Whitney, R R

    1982-09-01

    Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In the measurement method, an instrumentation system for measuring system voltage and current has been assembled. Different schemes of using the measurements to calculate system harmonic impedances have been studied. In the analytical method, a procedure to include various operating conditions has been proposed. Computer programs for both methods have been prepared, and the results of the measurement and analytical methods analyzed. A conclusion of the project is that the measurement and analytical methods both provided reasonable results. There are correlations between the measured and analytical results for most harmonics, although there are discrepancies between the assumptions used in the two methods. A sensitivity approach has been proposed to further correlate the results. From the results of the analysis, it is recommended that both methods should be tested further. For the measurement method, more testing should be done to cover different system operating conditions. In the analytical method, more detailed models for representing system components should be studied. In addition, alternative statistical and sensitivity approaches should be attempted.

  7. Methods, systems and apparatus for controlling operation of two alternating current (AC) machines

    DOEpatents

    Gallegos-Lopez, Gabriel; Nagashima, James M.; Perisic, Milun; Hiti, Silva

    2012-06-05

    A system is provided for controlling two alternating current (AC) machines via a five-phase PWM inverter module. The system comprises a first control loop, a second control loop, and a current command adjustment module. The current command adjustment module operates in conjunction with the first control loop and the second control loop to continuously adjust current command signals that control the first AC machine and the second AC machine such that they share the input voltage available to them without compromising the target mechanical output power of either machine. This way, even when the phase voltage available to either one of the machines decreases, that machine outputs its target mechanical output power.

  8. Design note about a 75 KVA quiet power distribution system

    SciTech Connect

    Visser, A.T.

    1984-04-05

    This note describes a 75KVA quiet power distribution system for X 653 in neutrino Lab D. It is fed from the regular AC distribution which exists in the building and it has no standby power. Its purpose is to remove electrical disturbances which are present on the regular AC distribution.

  9. Nearly Unity Power-Factor of the Modular Three-Phase AC to DC Converter with Minimized DC Bus Capacitor

    NASA Astrophysics Data System (ADS)

    Chunkag, Viboon; Kamnarn, Uthen

    The analysis and design of nearly unity power-factor and fast dynamic response of the modular three-phase ac to dc converter using three single-phase isolated SEPIC rectifier modules with minimized dc bus capacitor is discussed, based on power balance control technique. The averaged small-signal technique is used to obtain the inductor current compensator, thus resulting in the output impedance and audio susceptibility become zero, that is, the output voltage of the converter presented in this paper is independent of the variations of the dc load current and the utility voltage. The proposed system significantly improves the dynamic response of the converter to load steps with minimized dc bus capacitor for Distributed Power System (DPS). A 600W prototype modular three-phase ac to dc converter comprising three 200W single-phase SEPIC rectifier modules with the proposed control scheme has been designed and implemented. The proposed system is confirmed by experimental implementation.

  10. Plasma characteristics of argon glow discharge produced by AC power supply operating at low frequencies

    SciTech Connect

    Kongpiboolkid, Watcharapon; Mongkolnavin, Rattachat

    2015-04-24

    Non-thermal properties of Argon glow discharge operating with various operating pressures were measured and presented in this work. The Argon plasma is produced by a parallel conducting electrodes coupling with a high voltage AC power supply. The power supply can generate high AC voltage at various frequencies. The frequencies for the operation are in the range of a few kHz. The system is capable of generating electric field between the two metal electrodes discharge system. The characteristics of plasma produced were measured by optical emission spectroscopy (OES) technique where electron temperature (T{sub e}) and electron number density (n{sub e}) can be determined by line intensity ratio method. The value of electron number density was then determined from the Saha-Eggert equation. Our results show that the electron number density of the discharge obtained is of the order of 10{sup −17} − 10{sup −18} m{sup −3} where the electron temperature is between 1.00−2.00 eV for various operating frequencies used which are in good agreement with similar results published earlier.

  11. Power management system

    DOEpatents

    Algrain, Marcelo C.; Johnson, Kris W.; Akasam, Sivaprasad; Hoff, Brian D.

    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.

  12. Secondary power systems

    SciTech Connect

    Not Available

    1985-01-01

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

  13. The ac propulsion system for an electric vehicle, phase 1

    NASA Technical Reports Server (NTRS)

    Geppert, S.

    1981-01-01

    A functional prototype of an electric vehicle ac propulsion system was built consisting of a 18.65 kW rated ac induction traction motor, pulse width modulated (PWM) transistorized inverter, two speed mechanically shifted automatic transmission, and an overall drive/vehicle controller. Design developmental steps, and test results of individual components and the complex system on an instrumented test frame are described. Computer models were developed for the inverter, motor and a representative vehicle. A preliminary reliability model and failure modes effects analysis are given.

  14. EXT-II: a second generation advanced ac propulsion system

    SciTech Connect

    Bates, B.; Patil, P.B.; Ciccarelli, M.F.

    1986-01-01

    This paper discusses the characteristics of the concept and includes discussion of the system constraints, including traction battery constraints, and brief descriptions of the major subsystems being developed. The components discussed include: the system controller, dc to ac inverter, an internal permanent magnet ac motor and a two-speed automatic transmission with an integral final drive and differential. The motor and transmission are on a common axis and are integrated into one compact unit that is integral with the rear axle of the vehicle.

  15. Power Systems Integration Laboratory (Fact Sheet)

    SciTech Connect

    Not Available

    2011-10-01

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

  16. Sustainable AC/AC hybrid electrochemical capacitors in aqueous electrolyte approaching the performance of organic systems

    NASA Astrophysics Data System (ADS)

    Abbas, Qamar; Babuchowska, Paulina; Frąckowiak, Elżbieta; Béguin, François

    2016-09-01

    A high energy hybrid AC/AC electrochemical capacitor has been realized in aqueous Li2SO4+KI electrolyte mixture. Owing to the redox processes associated with the 2I-/I2 system, the positive electrode operates in narrow potential range and displays high capacity. During prolonged potentiostatic floating at 1.6 V, the hybrid cell demonstrates remarkably stable capacitance and resistance. Analyses by temperature programmed desorption after floating at 1.6 V proved that oxidation of the positive AC electrode is prevented by the use of Li2SO4+KI, which enables the maximum potential of this electrode to be shifted below the water oxidation potential. When charged at 0.2 A g-1 up to U = 1.6 V, the hybrid cell displays a high capacitance of 75 F g-1 (300 F g-1 per mass of one electrode) compared to 47 F g-1 (188 F g-1 per mass of one electrode) for a symmetric cell in Li2SO4. At 0.2 A g-1 up to 1.6 V, the hybrid capacitor in Li2SO4+KI displays an energy density of 26 Wh kg-1 which approaches the energy density of 30.9 Wh kg-1 measured when the same carbon is implemented in a capacitor using TEABF4/ACN electrolyte and charged up to 2.5 V.

  17. Measurement of klystron phase modulation due to ac-powered filaments

    NASA Technical Reports Server (NTRS)

    Finnegan, E. J.

    1977-01-01

    A technique for determining the intermodulation components in the RF spectrum of the S-band radar transmitter generated by having the klystron filaments heated by 400-Hz ac power is described. When the klystron is being operated with 400-Hz (ac) on the filament, the IPM is buried in the 400-Hz equipment interference noise. The modulation sidebands were separated and identified and found to be-67 db below the main carrier. This is well below the transmitter specifications, and operating the filaments on ac would not degrade the spectrum to where it would be detrimental to the radiated RF.

  18. 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.

  19. Motor power control circuit for ac induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1983-01-01

    A motor power control of the type which functions by controlling the power factor wherein one of the parameters of power factor current on time is determined by the on time of a triac through which current is supplied to the motor. By means of a positive feedback circuit, a wider range of control is effected.

  20. Power system restoration issues

    SciTech Connect

    Adibi, M.M. ); Kafka, R.J. )

    1991-04-01

    This article describes some of the problems encountered in the three phases of power system restoration (PSR). The three phases of PSR are: Planning for restart and reintegration of the bulk power supply; Actions during system degradation for saving and retaining critical sources of power; Restoration when the power system has stabilized at some degraded level.

  1. Voltage controller/current limiter for ac

    NASA Technical Reports Server (NTRS)

    Wu, T. T.

    1980-01-01

    Circuit protects ac power systems for overload failures, limits power surge and short-circuit currents to 150 percent of steady state level, regulates ac output voltage, and soft starts loads. Limiter generates dc error signal in response to line fluctuations and dumps power when overload is reached. Device is inserted between ac source and load.

  2. Methods, systems and apparatus for controlling operation of two alternating current (AC) machines

    DOEpatents

    Gallegos-Lopez, Gabriel; Nagashima, James M.; Perisic, Milun; Hiti, Silva

    2012-02-14

    A system is provided for controlling two AC machines. The system comprises a DC input voltage source that provides a DC input voltage, a voltage boost command control module (VBCCM), a five-phase PWM inverter module coupled to the two AC machines, and a boost converter coupled to the inverter module and the DC input voltage source. The boost converter is designed to supply a new DC input voltage to the inverter module having a value that is greater than or equal to a value of the DC input voltage. The VBCCM generates a boost command signal (BCS) based on modulation indexes from the two AC machines. The BCS controls the boost converter such that the boost converter generates the new DC input voltage in response to the BCS. When the two AC machines require additional voltage that exceeds the DC input voltage required to meet a combined target mechanical power required by the two AC machines, the BCS controls the boost converter to drive the new DC input voltage generated by the boost converter to a value greater than the DC input voltage.

  3. Development of a low-cost integrated 20-kW ac solar tracking sub- array for grid-connected PV power system applications. Phase 1, Annual technical report, 11 July 1995--31 July 1996

    SciTech Connect

    Stern, M.; West, R.; Fourer, G.; Whalen, W.; Van Loo, M.; Duran, G.

    1997-06-01

    The overall goal of this effort is to reduce the installed cost of utility scale grid connected photovoltaic power systems. The focus of the effort is on ``BOS`` (Balance-Of-System) component manufacturing technology, which essentially involves all PV power system engineering, manufacturing, assembly and construction tasks from the receipt of a PV module to the deliver of grid connected electricity.

  4. Single stage AC-DC converter for Galfenol-based micro-power energy harvesters

    NASA Astrophysics Data System (ADS)

    Cavaroc, Peyton; Curtis, Chandra; Naik, Suketu; Cooper, James

    2014-06-01

    Military based sensor systems are often hindered in operational deployment and/or other capabilities due to limitations in their energy storage elements. Typically operating from lithium based batteries, there is a finite amount of stored energy which the sensor can use to collect and transmit data. As a result, the sensors have reduced sensing and transmission rates. However, coupled with the latest advancements in energy harvesting, these sensors could potentially operate at standard sensing and transition rates as well as dramatically extend lifetimes. Working with the magnetostrictive material Galfenol, we demonstrate the production of enough energy to supplement and recharge a solid state battery thereby overcoming the deficiencies faced by unattended sensors. As with any vibration-based energy harvester, this solution produces an alternating current which needs to be rectified and boosted to a level conducive to recharge the storage element. This paper presents a power converter capable of efficiently converting an ultra-low AC voltage to a solid state charging voltage of 4.1VDC. While we are working with Galfenol transducers as our energy source, this converter may also be applied with any AC producing energy harvester, particularly at operating levels less than 2mW and 200mVAC.

  5. Non-oxidized porous silicon-based power AC switch peripheries

    NASA Astrophysics Data System (ADS)

    Menard, Samuel; Fèvre, Angélique; Valente, Damien; Billoué, Jérôme; Gautier, Gaël

    2012-10-01

    We present in this paper a novel application of porous silicon (PS) for low-power alternating current (AC) switches such as triode alternating current devices (TRIACs) frequently used to control small appliances (fridge, vacuum cleaner, washing machine, coffee makers, etc.). More precisely, it seems possible to benefit from the PS electrical insulation properties to ensure the OFF state of the device. Based on the technological aspects of the most commonly used AC switch peripheries physically responsible of the TRIAC blocking performances (leakage current and breakdown voltage), we suggest to isolate upper and lower junctions through the addition of a PS layer anodically etched from existing AC switch diffusion profiles. Then, we comment the voltage capability of practical samples emanating from the proposed architecture. Thanks to the characterization results of simple Al-PS-Si(P) structures, the experimental observations are interpreted, thus opening new outlooks in the field of AC switch peripheries.

  6. Non-oxidized porous silicon-based power AC switch peripheries.

    PubMed

    Menard, Samuel; Fèvre, Angélique; Valente, Damien; Billoué, Jérôme; Gautier, Gaël

    2012-01-01

    We present in this paper a novel application of porous silicon (PS) for low-power alternating current (AC) switches such as triode alternating current devices (TRIACs) frequently used to control small appliances (fridge, vacuum cleaner, washing machine, coffee makers, etc.). More precisely, it seems possible to benefit from the PS electrical insulation properties to ensure the OFF state of the device. Based on the technological aspects of the most commonly used AC switch peripheries physically responsible of the TRIAC blocking performances (leakage current and breakdown voltage), we suggest to isolate upper and lower junctions through the addition of a PS layer anodically etched from existing AC switch diffusion profiles. Then, we comment the voltage capability of practical samples emanating from the proposed architecture. Thanks to the characterization results of simple Al-PS-Si(P) structures, the experimental observations are interpreted, thus opening new outlooks in the field of AC switch peripheries. PMID:23057856

  7. Non-oxidized porous silicon-based power AC switch peripheries

    PubMed Central

    2012-01-01

    We present in this paper a novel application of porous silicon (PS) for low-power alternating current (AC) switches such as triode alternating current devices (TRIACs) frequently used to control small appliances (fridge, vacuum cleaner, washing machine, coffee makers, etc.). More precisely, it seems possible to benefit from the PS electrical insulation properties to ensure the OFF state of the device. Based on the technological aspects of the most commonly used AC switch peripheries physically responsible of the TRIAC blocking performances (leakage current and breakdown voltage), we suggest to isolate upper and lower junctions through the addition of a PS layer anodically etched from existing AC switch diffusion profiles. Then, we comment the voltage capability of practical samples emanating from the proposed architecture. Thanks to the characterization results of simple Al-PS-Si(P) structures, the experimental observations are interpreted, thus opening new outlooks in the field of AC switch peripheries. PMID:23057856

  8. Space nuclear power systems

    NASA Technical Reports Server (NTRS)

    Carpenter, R. T.

    1972-01-01

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

  9. System and method for determining stator winding resistance in an AC motor using motor drives

    DOEpatents

    Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

    2013-02-26

    A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

  10. System and component design and test of a 10 hp, 18,000 rpm AC dynamometer utilizing a high frequency AC voltage link, part 1

    NASA Astrophysics Data System (ADS)

    Lipo, Thomas A.; Alan, Irfan

    1991-06-01

    Hard and soft switching test results conducted with one of the samples of first generation MOS-controlled thyristor (MCTs) and similar test results with several different samples of second generation MCT's are reported. A simple chopper circuit is used to investigate the basic switching characteristics of MCT under hard switching and various types of resonant circuits are used to determine soft switching characteristics of MCT under both zero voltage and zero current switching. Next, operation principles of a pulse density modulated converter (PDMC) for three phase (3F) to 3F two-step power conversion via parallel resonant high frequency (HF) AC link are reviewed. The details for the selection of power switches and other power components required for the construction of the power circuit for the second generation 3F to 3F converter system are discussed. The problems encountered in the first generation system are considered. Design and performance of the first generation 3F to 3F power converter system and field oriented induction moter drive based upon a 3 kVA, 20 kHz parallel resonant HF AC link are described. Low harmonic current at the input and output, unity power factor operation of input, and bidirectional flow capability of the system are shown via both computer and experimental results. The work completed on the construction and testing of the second generation converter and field oriented induction motor drive based upon specifications for a 10 hp squirrel cage dynamometer and a 20 kHz parallel resonant HF AC link is discussed. The induction machine is designed to deliver 10 hp or 7.46 kW when operated as an AC-dynamo with power fed back to the source through the converter. Results presented reveal that the proposed power level requires additional energy storage elements to overcome difficulties with a peak link voltage variation problem that limits reaching to the desired power level. The power level test of the second generation converter after the

  11. System and component design and test of a 10 hp, 18,000 rpm AC dynamometer utilizing a high frequency AC voltage link, part 1

    NASA Technical Reports Server (NTRS)

    Lipo, Thomas A.; Alan, Irfan

    1991-01-01

    Hard and soft switching test results conducted with one of the samples of first generation MOS-controlled thyristor (MCTs) and similar test results with several different samples of second generation MCT's are reported. A simple chopper circuit is used to investigate the basic switching characteristics of MCT under hard switching and various types of resonant circuits are used to determine soft switching characteristics of MCT under both zero voltage and zero current switching. Next, operation principles of a pulse density modulated converter (PDMC) for three phase (3F) to 3F two-step power conversion via parallel resonant high frequency (HF) AC link are reviewed. The details for the selection of power switches and other power components required for the construction of the power circuit for the second generation 3F to 3F converter system are discussed. The problems encountered in the first generation system are considered. Design and performance of the first generation 3F to 3F power converter system and field oriented induction moter drive based upon a 3 kVA, 20 kHz parallel resonant HF AC link are described. Low harmonic current at the input and output, unity power factor operation of input, and bidirectional flow capability of the system are shown via both computer and experimental results. The work completed on the construction and testing of the second generation converter and field oriented induction motor drive based upon specifications for a 10 hp squirrel cage dynamometer and a 20 kHz parallel resonant HF AC link is discussed. The induction machine is designed to deliver 10 hp or 7.46 kW when operated as an AC-dynamo with power fed back to the source through the converter. Results presented reveal that the proposed power level requires additional energy storage elements to overcome difficulties with a peak link voltage variation problem that limits reaching to the desired power level. The power level test of the second generation converter after the

  12. Power Plant Systems Analysis

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  13. Scalable Heuristics for Planning, Placement and Sizing of Flexible AC Transmission System Devices

    SciTech Connect

    Frolov, Vladmir; Backhaus, Scott N.; Chertkov, Michael

    2015-07-02

    Aiming to relieve transmission grid congestion and improve or extend feasibility domain of the operations, we build optimization heuristics, generalizing standard AC Optimal Power Flow (OPF), for placement and sizing of Flexible Alternating Current Transmission System (FACTS) devices of the Series Compensation (SC) and Static VAR Compensation (SVC) type. One use of these devices is in resolving the case when the AC OPF solution does not exist because of congestion. Another application is developing a long-term investment strategy for placement and sizing of the SC and SVC devices to reduce operational cost and improve power system operation. SC and SVC devices are represented by modification of the transmission line inductances and reactive power nodal corrections respectively. We find one placement and sizing of FACTs devices for multiple scenarios and optimal settings for each scenario simultaneously. Our solution of the nonlinear and nonconvex generalized AC-OPF consists of building a convergent sequence of convex optimizations containing only linear constraints and shows good computational scaling to larger systems. The approach is illustrated on single- and multi-scenario examples of the Matpower case-30 model.

  14. Power Supply Systems for Rapid Cycling Synchrotron

    NASA Astrophysics Data System (ADS)

    Watanabe, Yasuhiro; Adachi, Toshikazu; Someya, Hirohiko; Koseki, Shoichiro; Ogawa, Shinichi

    JAEA and KEK are jointly constructing a high intensity proton accelerator project J-PARC. Its main accelerator is 3GeV rapid cycling synchrotron (RCS). Two types of resonant excitation systems, parallel and cascade, are introduced to excite DC biased 25Hz AC currents through its main magnets. The parallel excitation is adopted for dipole magnets power supply system, and the cascade excitations are adopted for seven family quadrupole magnets systems. In this paper, two systems are investigated and analyzed, and it is explained why different types are adopted to each system. Authors believe that such hybrid exciting systems are most suitable for high power RCS.

  15. Compensation for Harmonic Currents and Reactive Power in Wind Power Generation System using PWM Inverter

    NASA Astrophysics Data System (ADS)

    Shinohara, Katsuji; Shinhatsubo, Kurato; Iimori, Kenichi; Yamamoto, Kichiro; Saruban, Takamichi; Yamaemori, Takahiro

    In recent year, consciousness of environmental problems is enhancing, and the price of the electric power purchased by an electric power company is established expensive for the power plant utilizing the natural energy. So, the introduction of the wind power generation is promoted in Japan. Generally, squirrel-cage induction machines are widely used as a generator in wind power generation system because of its small size, lightweight and low-cost. However, the induction machines do not have a source of excitation. Thus, it causes the inrush currents and the instantaneous voltage drop when the generator is directly connected to a power grid. To reduce the inrush currents, an AC power regulator is used. Wind power generations are frequently connected to and disconnected from the power grid. However, when the inrush currents are reduced, harmonic currents are caused by phase control of the AC power regulator. And the phase control of AC power regulator cannot control the power factor. Therefore, we propose the use of the AC power regulator to compensate for the harmonic currents and reactive power in the wind power generation system, and demonstrate the validity of its system by simulated and experimental results.

  16. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered adjustable hospital bed. 880.5100 Section 880.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5100...

  17. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered medical examination light. 880.6320 Section 880.6320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Miscellaneous Devices § 880.6320...

  18. 21 CFR 880.6320 - AC-powered medical examination light.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered medical examination light. 880.6320 Section 880.6320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal...

  19. Power processing and control requirements of dispersed solar thermal electric generation systems

    NASA Technical Reports Server (NTRS)

    Das, R. L.

    1980-01-01

    Power Processing and Control requirements of Dispersed Receiver Solar Thermal Electric Generation Systems are presented. Kinematic Stirling Engines, Brayton Engines and Rankine Engines are considered as prime movers. Various types of generators are considered for ac and dc link generations. It is found that ac-ac Power Conversion is not suitable for implementation at this time. It is also found that ac-dc-ac Power Conversion with a large central inverter is more efficient than ac-dc-ac Power Conversion using small dispersed inverters. Ac-link solar thermal electric plants face potential stability and synchronization problems. Research and development efforts are needed in improving component performance characteristics and generation efficiency to make Solar Thermal Electric Generation economically attractive.

  20. 21 CFR 880.5500 - AC-powered patient lift.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... powered device either fixed or mobile, used to lift and transport patients in the horizontal or other required position from one place to another, as from a bed to a bath. The device includes straps and slings to support the patient. (b) Classification. Class II (special controls). The device is exempt...

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  2. Bimode uninterruptible power supply compatibility in renewable hybrid energy systems

    SciTech Connect

    Bower, W. ); O'Sullivan, G. )

    1990-08-01

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

  3. Comprehensive review of high power factor ac-dc boost converters for PFC applications

    NASA Astrophysics Data System (ADS)

    De Castro Pereira, Dênis; Da Silva, Márcio Renato; Mateus Silva, Elder; Lessa Tofoli, Fernando

    2015-08-01

    High power factor rectifiers have been consolidated as an effective solution to improve power quality indices in terms of input power factor correction, reduction in the total harmonic distortion of the input current and also regulated dc voltages. Within this context, this subject has motivated the introduction of numerous converter topologies based on classic dc-dc structures associated with novel control techniques, thus leading to the manufacturing of dedicated integrated circuits that allow high input power factor by adding a front-end stage to switch-mode converters. In particular, boost converters in continuous current mode (CCM) are widely employed since they allow obtaining minimised electromagnetic interference levels. This work is concerned with a literature review involving relevant ac-dc single-phase boost-based topologies with high input power factor. The evolution of aspects regarding the conventional boost converter is shown in terms of improved characteristics inherent to other ac-dc boost converters. Additionally, the work intends to be a fast and concise reference to single-phase ac-dc boost converters operating in CCM for engineers, researchers and experts in the field of power electronics by properly analysing and comparing the aforementioned rectifiers.

  4. 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.

  5. AC loss in high-temperature superconducting conductors, cables and windings for power devices

    NASA Astrophysics Data System (ADS)

    Oomen, M. P.; Rieger, J.; Hussennether, V.; Leghissa, M.

    2004-05-01

    High-temperature superconducting (HTS) transformers and reactor coils promise decreased weight and volume and higher efficiency. A critical design parameter for such devices is the AC loss in the conductor. The state of the art for AC-loss reduction in HTS power devices is described, starting from the loss in the single HTS tape. Improved tape manufacturing techniques have led to a significant decrease in the magnetization loss. Transport-current loss is decreased by choosing the right operating current and temperature. The role of tape dimensions, filament twist and resistive matrix is discussed and a comparison is made between state-of-the-art BSCCO and YBCO tapes. In transformer and reactor coils the AC loss in the tape is influenced by adjacent tapes in the coil, fields from other coils, overcurrents and higher harmonics. These factors are accounted for by a new AC-loss prediction model. Field components perpendicular to the tape are minimized by optimizing the coil design and by flux guidance pieces. High-current windings are made of Roebel conductors with transposed tapes. The model iteratively finds the temperature distribution in the winding and predicts the onset of thermal instability. We have fabricated and tested several AC windings and used them to validate the model. Now we can confidently use the model as an engineering tool for designing HTS windings and for determining the necessary tape properties.

  6. Economical space power systems

    NASA Technical Reports Server (NTRS)

    Burkholder, J. H.

    1980-01-01

    A commercial approach to design and fabrication of an economical space power system is investigated. Cost projections are based on a 2 kW space power system conceptual design taking into consideration the capability for serviceability, constraints of operation in space, and commercial production engineering approaches. A breakdown of the system design, documentation, fabrication, and reliability and quality assurance estimated costs are detailed.

  7. International Space Station Power Systems

    NASA Technical Reports Server (NTRS)

    Propp, Timothy William

    2001-01-01

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

  8. Power system commonality study

    NASA Astrophysics Data System (ADS)

    Littman, Franklin D.

    1992-07-01

    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 report along with a mass comparison. Other criteria such as life cycle cost (which includes transportation cost), reliability, safety, risk, and operability should be used in future, more detailed studies to select optimum power system architectures. Nineteen potential power system concepts were identified and evaluated for planetary surface applications including photovoltaic arrays with energy storage, isotope, and nuclear power systems. A top level environmental factors study was completed to assess environmental impacts on the identified power system concepts for both lunar and Mars applications. Potential power system design solutions for commonality between Mars and lunar applications were identified. Isotope, photovoltaic array (PVA), regenerative fuel cell (RFC), stainless steel liquid-metal cooled reactors (less than 1033 K maximum) with dynamic converters, and in-core thermionic reactor systems were found suitable for both lunar and Mars environments. The use of SP-100 thermoelectric (TE) and SP-100 dynamic power systems in a vacuum enclosure may also be possible for Mars applications although several issues need to be investigated further (potential single point failure of enclosure, mass penalty of enclosure and active pumping system, additional installation time and complexity). There are also technical issues involved with development of thermionic reactors (life, serviceability, and adaptability to other power conversion units). Additional studies are required to determine the optimum reactor concept for Mars applications. Various screening

  9. Space Nuclear Power Systems

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.

    2012-01-01

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

  10. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Walters, Jerry L.; Petrik, Edward J.; Roth, Mary Ellen; Truong, Long Van; Quinn, Todd; Krawczonek, Walter M.

    1990-01-01

    The Autonomous Power Expert (APEX) system was designed to monitor and diagnose fault conditions that occur within the Space Station Freedom Electrical Power System (SSF/EPS) Testbed. APEX is designed to interface with SSF/EPS testbed power management controllers to provide enhanced autonomous operation and control capability. The APEX architecture consists of three components: (1) a rule-based expert system, (2) a testbed data acquisition interface, and (3) a power scheduler interface. Fault detection, fault isolation, justification of probable causes, recommended actions, and incipient fault analysis are the main functions of the expert system component. The data acquisition component requests and receives pertinent parametric values from the EPS testbed and asserts the values into a knowledge base. Power load profile information is obtained from a remote scheduler through the power scheduler interface component. The current APEX design and development work is discussed. Operation and use of APEX by way of the user interface screens is also covered.

  11. Power systems integration

    SciTech Connect

    Brantley, L.W.

    1982-06-01

    Power systems integration in large flexible space structures is discussed with emphasis upon body control. A solar array is discussed as a typical example of spacecraft configuration problems. Information on how electric batteries dominate life-cycle costs is presented in chart form. Information is given on liquid metal droplet generators and collectors, hot spot analysis, power dissipation in solar arrays, solar array protection optimization, and electromagnetic compatibility for a power system platform.

  12. A novel approach implementing AC position servo system

    NASA Astrophysics Data System (ADS)

    Li, Bo; Sun, Li; Kang, Erliang; Esmaeli, Abdolreza

    2005-12-01

    This paper proposed a method which was based on DSP and FPGA and applied in the fully digital and high-performance permanent magnet synchronous motor (PMSM) AC servo system. In the system, the position loop control combined PI control and feedforward control was implemented by DSP unit, while the speed loop and current loop control were implemented by FPGA unit. Since FPGA provided a kind of hardware design scheme for the control system, it had the features of a special control IC. The functions of vector control algorithm, velocity and current sampling, space vector pulse width modulation and PI algorithm were included in the special control IC. In the meanwhile, it also provided host communication interfaces that could realize the real-time modification of the control parameters in the IC. Finally, the experimental results indicate that this system has high-speed response and well static state control performance.

  13. Power conditioning system for energy sources

    SciTech Connect

    Mazumder, Sudip K.; Burra, Rajni K.; Acharya, Kaustuva

    2008-05-13

    Apparatus for conditioning power generated by an energy source includes an inverter for converting a DC input voltage from the energy source to a square wave AC output voltage, and a converter for converting the AC output voltage from the inverter to a sine wave AC output voltage.

  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. Space Station Power System

    NASA Technical Reports Server (NTRS)

    Baraona, C. R.

    1984-01-01

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

  16. Space Station power system

    SciTech Connect

    Baraona, C.R.

    1984-04-01

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

  17. Point of collapse and continuation methods for large ac/dc systems

    SciTech Connect

    Canizares, C.A. ); Alvarado, F.L. )

    1993-02-01

    This paper describes the implementation of both Point of Collapse (PoC) methods and continuation methods for the computation of voltage collapse points (saddle-node bifurcations) in large ac/dc systems. A comparison of the performance of these methods is presented for real systems of up to 2,158 buses. The paper discusses computational details of the implementation of the PoC and continuation methods, and the unique challenges encountered due to the presence of high voltage direct current (HVDC) transmission, area interchange power control regulating transformers, and voltage and reactive power limits. The characteristics of a robust PoC power flow program are presented, and its application to detection and solution of voltage stability problems is demonstrated.

  18. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

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

  19. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

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

  20. Modeling of DC spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Berry, F. C.

    1995-01-01

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

  1. 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.

  2. Heavy Vehicle Essential Power Systems Workshop

    SciTech Connect

    Susan Rogers

    2001-12-12

    Essential power is a crosscutting technology area that addresses the efficient and practical management of electrical and thermal requirements on trucks. Essential Power Systems: any function on the truck, that is not currently involved in moving the truck, and requires electrical or mechanical energy; Truck Lights; Hotel Loads (HVAC, computers, appliances, lighting, entertainment systems); Pumps, starter, compressor, fans, trailer refrigeration; Engine and fuel heating; and Operation of power lifts and pumps for bulk fluid transfer. Transition from ''belt and gear driven'' to auxiliary power generation of electricity - ''Truck Electrification'' 42 volts, DC and/ or AC; All electrically driven auxiliaries; Power on demand - manage electrical loads; Benefits include: increased fuel efficiency, reduced emission both when truck is idling and moving down the road.

  3. Nuclear power system

    SciTech Connect

    Yampolsky, J.S.; Cavallaro, L.; Paulovich, K.F.; Schleicher, R.W.

    1989-09-05

    This patent describes an inherently safe modular nuclear power system for producing electrical power at acceptable efficiency levels using working fluids at relatively low temperatures and pressures. The system comprising: a reactor module for heating a first fluid; a heat exchanger module for transferring heat from the first fluid to a second fluid; a first piping system effecting flow of the first fluid in a first fluid circuit successively through the reactor module and the heat exchanger module; a power conversion module comprising a turbogenerator driven by the second fluid, and means for cooling the second fluid upon emergence thereof from the turbogenerator; a second piping system comprising means for effecting flow of the second fluid in a second fluid circuit successively through the heat exchanger module and the power conversion module; and a plurality of pits for receiving the modules.

  4. Solar power system

    SciTech Connect

    Hasford, G.S.

    1990-01-30

    This patent describes a solar power system. It comprises: solar concentrator means; power conversion means for converting solar energy from the solar concentrator means to electrical energy, through the medium of a working fluid, to power appropriate loads; integrated combustor/heat exchanger means coupled to the power conversion means for heating the working fluid during periods of solar eclipse and giving off a water combustion product; electrolyzer means for receiving the water combustion product from the integrated combustor/heat exchanger mean and regenerating the water combustion product to gaseous hydrogen and oxygen. The electrolyzer means being coupled to the power conversion means as to be powered thereby during periods of excess electrical energy; and means for supplying the hydrogen and oxygen for combustion in the integrated combustor/heat exchanger during the periods of solar eclipse.

  5. System and method for determining stator winding resistance in an AC motor

    DOEpatents

    Lu, Bin; Habetler, Thomas G.; Zhang, Pinjia; Theisen, Peter J.

    2011-05-31

    A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

  6. Wind power generating system

    SciTech Connect

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

    1985-03-12

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

  7. 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.

  8. Solar Dynamic Power System Stability Analysis and Control

    NASA Technical Reports Server (NTRS)

    Momoh, James A.; Wang, Yanchun

    1996-01-01

    The objective of this research is to conduct dynamic analysis, control design, and control performance test of solar power system. Solar power system consists of generation system and distribution network system. A bench mark system is used in this research, which includes a generator with excitation system and governor, an ac/dc converter, six DDCU's and forty-eight loads. A detailed model is used for modeling generator. Excitation system is represented by a third order model. DDCU is represented by a seventh order system. The load is modeled by the combination of constant power and constant impedance. Eigen-analysis and eigen-sensitivity analysis are used for system dynamic analysis. The effects of excitation system, governor, ac/dc converter control, and the type of load on system stability are discussed. In order to improve system transient stability, nonlinear ac/dc converter control is introduced. The direct linearization method is used for control design. The dynamic analysis results show that these controls affect system stability in different ways. The parameter coordination of controllers are recommended based on the dynamic analysis. It is concluded from the present studies that system stability is improved by the coordination of control parameters and the nonlinear ac/dc converter control stabilize system oscillation caused by the load change and system fault efficiently.

  9. Power transmission cable development for the Space Station Freedom electrical power system

    NASA Technical Reports Server (NTRS)

    Schmitz, Gregory V.; Biess, John J.

    1989-01-01

    Power transmission cable is presently being evaluated under a NASA Lewis Research Center advanced development contract for application in the Space Station Freedom (SSF) electrical power system (EPS). Evaluation testing has been performed by TRW and NASA Lewis Research Center. The results of this development contract are presented. The primary cable design goals are to provide (1) a low characteristic inductance to minimize line voltage drop at 20 kHz, (2) electromagnetic compatibility control of the 20-kHz ac power current, (3) a physical configuration that minimizes ac resistance and (4) release of trapped air for corona-free operation.

  10. Power Systems Development Facility

    SciTech Connect

    Southern Company Services

    2009-01-31

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

  11. The influence of bending strains on AC power losses in multifilamentary BSCCO-2223/Ag tapes

    NASA Astrophysics Data System (ADS)

    Tsukamoto, O.; Ciszek, M.; Suzuki, H.; Ogawa, J.

    2006-08-01

    Recent advances in the manufacturing of multifilamentary high temperature superconducting composite wires allow for wider practical applications of the conductors, e.g. in power transmission cables, transformers and motors. The wires, based mainly on BSCCO-2223 and YBCO-123 cuprates, are used in the forms of variously shaped coils; therefore they are subjected to different kinds of mechanical stresses and strains. These, in turn, lead to some changes in the physical parameters of the superconducting material, mainly in the critical current density, and thus in the dissipated electromagnetic energy, when subjected to changing magnetic fields and transport currents. In this work we report some experimental results related to the AC loss characteristics of Bi-2223/Ag multifilamentary tapes and their dependences on bending strains. These losses are compared to the losses of virgin, straight tapes. The total AC losses, i.e. transport current and magnetization losses, in the Bi-2223/Ag tapes, were measured by means of the electrical and calorimetric methods. The experimental data obtained are compared with the critical state model predictions for AC loss behaviour in the experimental conditions presented here.

  12. Single and three-phase AC losses in HTS superconducting power transmission line prototype cables

    SciTech Connect

    Daney, D.E.; Boenig, H.J.; Maley, M.P.; Coulter, J.Y.; Fleshler, S.

    1997-11-01

    AC losses in two, one-meter-long lengths of HTS prototype multi-strand conductors (PMC`s) are measured with a temperature-difference calorimeter. Both single-phase and three-phase losses are examined with ac currents up to 1,000 A rms. The calorimeter, designed specifically for these measurements, has a precision of 1 mW. PMC {number_sign}1 has two helically-wound, non-insulated layers of HTS tape (19 tapes per layer), each layer wrapped with opposite pitch. PMC {number_sign}2 is identical except for insulation between the layers. The measured ac losses show no significant effect of interlayer insulation and depend on about the third power of the current--a result in agreement with the Bean-Norris model adapted to the double-helix configuration. The three-phase losses are a factor of two higher than those exhibited by a single isolated conductor, indicating a significant interaction between phases.

  13. Plasma antennas driven by 5–20 kHz AC power supply

    SciTech Connect

    Zhao, Jiansen Chen, Yuli; Sun, Yang; Wu, Huafeng; Liu, Yue; Yuan, Qiumeng

    2015-12-15

    The experiments described in this work were performed with the aim of introducing a new plasma antenna that was excited by a 5–20 kHz alternating current (AC) power supply, where the antenna was transformed into a U-shape. The results show that the impedance, voltage standing-wave ratio (VSWR), radiation pattern and gain characteristics of the antenna can be controlled rapidly by varying not only the discharge power, but also by varying the discharge frequency in the range from 5 to 20 kHz. When the discharge frequency is adjusted from 10 to 12 kHz, the gain is higher within a relatively broad frequency band and the switch-on time is less than 1 ms when the discharge power is less than 5 W, meaning that the plasma antenna can be turned on and off rapidly.

  14. Development of an AC power source for CSEM method using full-bridge switching configuration

    NASA Astrophysics Data System (ADS)

    Indrasari, Widyaningrum; Srigutomo, Wahyu; Djamal, Mitra; S, Rahmondia N.

    2015-04-01

    The electromagnetic (EM) method has been widely used in geophysical surveys. It is a non-destructive method that utilizes electromagnetic waves in characterizing subsurface profiles. Generally, EM method can be divided into passive EM and active EM. The passive EM uses the natural electromagnetic field sources, while the active EM or Controlled Source EM (CSEM) uses artificial source to generate electromagnetic wave. In this paper, we present the development of AC power source for CSEM transmitter. As the power source we used AC source with sine wave signal. To satisfy a high power and high voltage in the equipment, we used the full-bridge configuration switching. It works on 990 Hz maximum frequency, and can deliver maximum current of 1.9 A at 620 V. The switching is controlled by microcontroller using Pulse Width Modulation (PWM) and the driver of inverter is built using IGBT. The output frequency can be varied from 1 Hz to 990 Hz. For varied frequencies the harmonic distortion is different due to switching speed. As frequency increase the harmonic distortion also increase. We found that the total harmonic distortion can be reduced to 1 % at the output with 330 Hz.

  15. Sub-micrometer particles produced by a low-powered AC electric arc in liquids.

    PubMed

    Jaworski, Jacek A; Fleury, Eric

    2012-01-01

    The article presents the report of the production of composites of sub-micrometer metal particles in matrix consisted of the metal compounds by means of an AC electric arc in water and paraffin solutions using electrodes carbon-metal and metal-metal (metal: Ni, Fe, Co, Cu). The advantage of this method is the low electric power (from 5 to 10 W) needed in comparison to standard DC arc-discharge methods (0.8 to 3 kW). This method enables the production of particles from conductive material also in wide range of temperature and in solvent which could be either transparent to light or opaque. Moreover the solvent can be electrolyte or insulating liquid. The microstructure of the composite layer was investigated by scanning electron microscopy (SEM), Electron Probe Microanalysis (EPMA) and X-ray. During particles production in water metal oxides were created. Additionally using cobalt-copper, nickel-copper as couple electrodes, insoluble in water copper (II) hydroxide crystal grains were created additionally which crystals shape was depended on transition metal. For iron-copper couple electrodes system the copper (II) hydroxide was not formed. Experiments with sequence production of Ni and Fe particles with C electrode assisting in molten paraffin let to obtain both Ni and Fe particles surrounded by paraffin. After solidification the material was insulator but if locally magnetic field influenced on the liquid solution in that place after solidification a new composite was created which was electric current conductor with resistivity around 0.1 omega x m, was attracted by magnetic field and presented magneto resistance around 0.4% in changing magnetic field in a range 150 mT. After mixing the concentrated paraffin with normal paraffin resistivity of the mixture increased and it became photosensitive and created small voltage under light influence. PMID:22524027

  16. Power Delivery from an Actual Thermoelectric Generation System

    NASA Astrophysics Data System (ADS)

    Kaibe, Hiromasa; Kajihara, Takeshi; Nagano, Kouji; Makino, Kazuya; Hachiuma, Hirokuni; Natsuume, Daisuke

    2014-06-01

    Similar to photovoltaic (PV) and fuel cells, thermoelectric generators (TEGs) supply direct-current (DC) power, essentially requiring DC/alternating current (AC) conversion for delivery as electricity into the grid network. Use of PVs is already well established through power conditioning systems (PCSs) that enable DC/AC conversion with maximum-power-point tracking, which enables commercial use by customers. From the economic, legal, and regulatory perspectives, a commercial PCS for PVs should also be available for TEGs, preferably as is or with just simple adjustment. Herein, we report use of a PV PCS with an actual TEG. The results are analyzed, and proper application for TEGs is proposed.

  17. Simulation analysis of three-phase current type AC-to-DC converter with high power factor

    SciTech Connect

    Okui, Yoshiaki; Yamada, Hajime

    1997-03-01

    A new three-phase current type AC-to-DC converter has been developed by the authors. This paper describes the principle of the circuit operation and the circuit configuration of the AC-to-DC converter controlled by PWM. Simulation analysis of each waveform, such as AC and DC voltages and currents, are calculated by Euler`s method. The simulated values of the total power factor agreed with the measured values within the difference of 5.8% on the condition of full load, 10kW. When the AC side voltage is unbalanced, it is found by simulation that the total harmonic distortion controlled by both feedforward control and AC side current feedback control (proportion gain, k{sub 4} = 1) is restrained at only 38% compared with only feedforward control (k{sub 4} = 0).

  18. 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

  19. 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

  20. 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.

  1. On two-liquid AC electroosmotic system for thin films.

    PubMed

    Navarkar, Abhishek; Amiroudine, Sakir; Demekhin, Evgeny A

    2016-03-01

    Lab-on-chip devices employ EOF for transportation and mixing of liquids. However, when a steady (DC) electric field is applied to the liquids, there are undesirable effects such as degradation of sample, electrolysis, bubble formation, etc. due to large magnitude of electric potential required to generate the flow. These effects can be averted by using a time-periodic or AC electric field. Transport and mixing of nonconductive liquids remain a problem even with this technique. In the present study, a two-liquid system bounded by two rigid plates, which act as substrates, is considered. The potential distribution is derived by assuming a Boltzmann charge distribution and using the Debye-Hückel linearization. Analytical solution of this time-periodic system shows some effects of viscosity ratio and permittivity ratio on the velocity profile. Interfacial electrostatics is also found to play a significant role in deciding velocity gradients at the interface. High frequency of the applied electric field is observed to generate an approximately static velocity profile away from the Electric Double Layer (EDL). PMID:26773725

  2. Numerical study on AC loss characteristics of superconducting power transmission cables comprising coated conductors with magnetic substrates

    NASA Astrophysics Data System (ADS)

    Amemiya, N.; Nakahata, M.

    2007-10-01

    Electromagnetic field analyses were made for mono-layer conductors comprising coated conductors for superconducting power transmission cables in order to evaluate their AC loss characteristics. We focused on the magnetic properties of the substrates of coated conductors. The current distribution in each coated conductor and the magnetic flux profile around each coated conductor were visualized. The influence of relative permeability and the space between coated conductors on the AC loss characteristics of mono-layer conductors were studied based on the visualized current and magnetic flux distributions. The influence of a saturated magnetic property on a calculated AC loss was also discussed.

  3. Power line detection system

    DOEpatents

    Latorre, Victor R.; Watwood, Donald B.

    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.

  4. Power line detection system

    DOEpatents

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

    1994-09-27

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

  5. A self-powered AC magnetic sensor based on piezoelectric nanogenerator

    NASA Astrophysics Data System (ADS)

    Yu, Aifang; Song, Ming; Zhang, Yan; Kou, Jinzong; Zhai, Junyi; Wang, Zhong Lin

    2014-11-01

    An AC magnetic field, which is a carrier of information, is distributed everywhere and is continuous. How to use and detect this field has been an ongoing topic over the past few decades. Conventional magnetic sensors are usually based on the Hall Effect, the fluxgate, a superconductor quantum interface or magnetoelectric or magnetoresistive sensing. Here, a flexible, simple, low-cost and self-powered active piezoelectric nanogenerator (NG) is successfully demonstrated as an AC magnetic field sensor at room temperature. The amplitude and frequency of a magnetic field can both be accurately sensed by the NG. The output voltage of the NG has a good linearity with a measured magnetic field. The detected minute magnetic field is as low as 1.2 × 10-7 tesla, which is 400 times greater than a commercial magnetic sensor that uses the Hall Effect. In comparison to the existing technologies, an NG is a room-temperature self-powered active sensor that is very simple and very cheap for practical applications.

  6. A self-powered AC magnetic sensor based on piezoelectric nanogenerator.

    PubMed

    Yu, Aifang; Song, Ming; Zhang, Yan; Kou, Jinzong; Zhai, Junyi; Lin Wang, Zhong

    2014-11-14

    An AC magnetic field, which is a carrier of information, is distributed everywhere and is continuous. How to use and detect this field has been an ongoing topic over the past few decades. Conventional magnetic sensors are usually based on the Hall Effect, the fluxgate, a superconductor quantum interface or magnetoelectric or magnetoresistive sensing. Here, a flexible, simple, low-cost and self-powered active piezoelectric nanogenerator (NG) is successfully demonstrated as an AC magnetic field sensor at room temperature. The amplitude and frequency of a magnetic field can both be accurately sensed by the NG. The output voltage of the NG has a good linearity with a measured magnetic field. The detected minute magnetic field is as low as 1.2 × 10(-7) tesla, which is 400 times greater than a commercial magnetic sensor that uses the Hall Effect. In comparison to the existing technologies, an NG is a room-temperature self-powered active sensor that is very simple and very cheap for practical applications. PMID:25333328

  7. Effect of AC target power on AlN film quality

    SciTech Connect

    Knisely, Katherine Grosh, Karl

    2014-09-01

    The influence of alternating current (AC) target power on film stress, roughness, and x-ray diffraction rocking curve full width half maximum (FWHM) was examined for AlN films deposited using S-gun magnetron sputtering on insulative substrates consisting of Si wafers with 575 nm thermal oxide. As the AC target power was increased from 5 to 8 kW, the deposition rate increased from 9.3 to 15.9 A/s, film stress decreased from 81 to −170 MPa, and the rocking curve FWHM increased from 0.98 to 1.03°. AlN film behavior is observed to change with target life; films deposited at 200 kWh target life were approximately 40 MPa more compressive and had 0.02° degree higher rocking curve FWHM values than films deposited at 130 kWh. AlN films deposited in two depositions were compared with films deposited in a single deposition, in order to better characterize the growth behavior and properties of AlN films deposited on an existing AlN film, which is not well understood. Two deposition films, when compared with single deposition films, showed no variation in residual stress trends or grain size behavior, but the average film roughness increased from 0.7 to 1.4 nm and rocking curve FWHM values increased by more than 0.25°.

  8. Ac resonant charger with charge rate unrelated to preimary power requency

    DOEpatents

    Not Available

    1979-12-07

    An ac resonant charger for a capacitive load, such as a pulse forming network (PFN), is provided with a variable repetition rate unrelated to the frequency of a multi-phase ac power source by using a control unit to select and couple the phase of the power source to the resonant charger in order to charge the capacitive load with a phase that is the next to begin a half cycle. For optimum range in repetition rate and increased charging voltage, the resonant charger includes a step-up transformer and full-wave rectifier. The next phase selected may then be of either polarity, but is always selected to be of a polarity opposite the polarity of the last phase selected so that the transformer core does not saturate. Thyristors are used to select and couple the correct phase just after its zero crossover in response to a sharp pulse generated by a zero-crossover detector. The thyristor that is turned on then automatically turns off after a full half cycle of its associated phase input. A full-wave rectifier couples the secondary winding of the transformer to the load so that the load capacitance is always charged with the same polarity.

  9. AC Resonant charger with charge rate unrelated to primary power frequency

    DOEpatents

    Watson, Harold

    1982-01-01

    An AC resonant charger for a capacitive load, such as a PFN, is provided with a variable repetition rate unrelated to the frequency of a multi-phase AC power source by using a control unit to select and couple the phase of the power source to the resonant charger in order to charge the capacitive load with a phase that is the next to begin a half cycle. For optimum range in repetition rate and increased charging voltage, the resonant charger includes a step-up transformer and full-wave rectifier. The next phase selected may then be of either polarity, but is always selected to be of a polarity opposite the polarity of the last phase selected so that the transformer core does not saturate. Thyristors are used to select and couple the correct phase just after its zero crossover in response to a sharp pulse generated by a zero-crossover detector. The thyristor that is turned on then automatically turns off after a full half cycle of its associated phase input. A full-wave rectifier couples the secondary winding of the transformer to the load so that the load capacitance is always charged with the same polarity.

  10. 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.

  11. An AC magnetohydrodynamic micropump: towards a true integrated microfluidic system

    SciTech Connect

    Lee, A P; Lemoff, A V; McConaghy, C F; Miles, R R

    1999-03-01

    An AC Magnetohydrodynamic (MHD) micropump has been demonstrated in which the Lorentz force is used to propel an electrolytic solution along a microchannel etched in silicon. This micropump has no moving parts, produces a continuous (not pulsatile) flow, and is compatible with solutions containing biological specimens. micropump, using the Lorentz force as the pumping mechanism for biological analysis. The AC Magnetohydrodynamic (MHD) micropump investigated produces a continuous flow and allows for complex microchannel design.

  12. Characterization of an Ac transposon system based on apt1-m1 (Ac) on the long arm of maize chromosome 9.

    PubMed

    Wang, Fei; Li, Pengfei; Tang, Yuanping; Fan, Jun; Xu, Dabin; Guo, Shengming; Xu, Zhengkai; Song, Rentao

    2012-09-01

    Activator/Dissociation (Ac/Ds) transposable elements have been used in maize insertional mutagenesis as a complement to Mutator (Mu). In this study, to further improve the efficiency of the Ac/Ds mutagenesis system, we adopted apt1-m1 (Ac) on the long arm of chromosome 9 (9L) as a donor Ac to create an Ac insertion library. This system is based on the negative selection pressure against the donor Ac, and it was highly efficient for isolating new transposition events. We obtained 9,625 transposition events from 1083 F1 ears with an average transposition rate of 8.66 % (rates ranged from 1.11 to 29.73 %). We also adopted a modified PCR-based genome walking strategy to improve the efficiency of the new method for isolating transposon-flanking sequences. This method is more efficient than the Southern-based method that was used in previous studies. A validation step was developed to distinguish transposon tags derived from newly transposed Ac or Ds elements. Using this PCR-based method, we isolated 67 inheritable flanking sequences from the apt1-m1 (Ac) transposition library; of these, 51 were confirmed as tr-Ac-flanking sequences and 11 were tr-Ds-flanking sequences. Similar to other Ac donors from different loci, the apt1-m1 (Ac) system also exhibited a preference for short distance transposition. In this study, we have further improved the Ac mutagenesis system in maize for gene isolation and functional genomics studies. PMID:23054225

  13. Analysis of large power systems

    NASA Technical Reports Server (NTRS)

    Dommel, H. W.

    1975-01-01

    Computer-oriented power systems analysis procedures in the electric utilities are surveyed. The growth of electric power systems is discussed along with the solution of sparse network equations, power flow, and stability studies.

  14. Representation of FACTS devices in power system economic dispatch

    SciTech Connect

    Taranto, G.N.; Pinto, L.M.V.G. ); Pereira, M.V.F. )

    1992-05-01

    This paper presents a methodology for representing FACTS (Flexible AC Transmission System) devices such as phase shifters and series compensation in power system operation. The proposed approach is based on mathematical decomposition and network compensation techniques. It is possible to incorporate existing optimal power flow algorithms, thus taking advantage of accumulated experience in optimization methods and reducing software development costs. A case study with a Brazilian-derived system is presented and discussed.

  15. Prospects of thermionic power systems

    NASA Technical Reports Server (NTRS)

    Shimada, K.

    1978-01-01

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

  16. Power systems testing

    NASA Technical Reports Server (NTRS)

    1991-01-01

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

  17. Wireless power transfer system

    DOEpatents

    Wu, Hunter; Sealy, Kylee; Gilchrist, Aaron

    2016-02-23

    A system includes a first stage of an inductive power transfer system with an LCL load resonant converter with a switching section, an LCL tuning circuit, and a primary receiver pad. The IPT system includes a second stage with a secondary receiver pad, a secondary resonant circuit, a secondary rectification circuit, and a secondary decoupling converter. The secondary receiver pad connects to the secondary resonant circuit. The secondary resonant circuit connects to the secondary rectification circuit. The secondary rectification circuit connects to the secondary decoupling converter. The second stage connects to a load. The load includes an energy storage element. The second stage and load are located on a vehicle and the first stage is located at a fixed location. The primary receiver pad wirelessly transfers power to the secondary receiver pad across a gap when the vehicle positions the secondary receiver pad with respect to the primary receiver pad.

  18. Increased deposition of polychlorinated biphenyls (PCBs) under an AC high-voltage power line

    NASA Astrophysics Data System (ADS)

    Öberg, Tomas; Peltola, Pasi

    2009-12-01

    There is considerable public concern regarding the potential risks to health of electromagnetic fields in general and high-voltage power lines in particular. As epidemiological findings are not supported by a clearly defined mechanism of direct magnetic field interactions with the human body, potential indirect effects are of interest. It has been suggested that an increased exposure to chemical pollutants could occur near high-voltage power lines due to formation and deposition of charged aerosols. The current study reports empirical evidence that seems to support this hypothesis. The deposition of 18 congeners of polychlorinated biphenyls (PCBs) was studied by collecting samples of pine needles under a 400 kV AC power line and at reference sites in the vicinity. Compared to the reference sites, the average deposition of PCB congeners under the power line was almost double. This difference between the two groups of samples was statistically significant. While it is premature to draw any conclusions regarding the human exposure near high-voltage power lines, the issue deserves attention and further investigations.

  19. Power Quality Improvement in Bridgeless Ac-Dc Converter Based Multi-output Switched Mode Power Supply

    NASA Astrophysics Data System (ADS)

    Singh, Shihka; Singh, Bhim; Bhuvaneswari, G.; Bist, Vashist

    2014-12-01

    Computer power supplies are required to have multiple isolated regulated dc voltages with low ripple content and high input power factor at the utility interface. A dc-dc converter is used for obtaining these isolated multi-output dc voltages with excellent regulation. In this paper, a non-isolated ac-dc converter is proposed as the first stage converter to obtain a regulated dc output rather than using a simple uncontrolled diode bridge rectifier at the front end. A dc-dc converter is used at the second stage that has a high frequency transformer with multiple secondary windings to obtain different dc voltage levels at the output. The proposed bridgeless converter based power supply is designed using fundamental design equations, and different component values are calculated. Extensive simulations are carried out to demonstrate the improved performance of the proposed bridgeless converter based multi-output computer power supply at varying source voltages and load conditions. Experimental validation of the power supply is carried on a developed hardware prototype, and the test results are compared with the simulated performance for design verification.

  20. High power connection system

    DOEpatents

    Schaefer, Christopher E.; Beer, Robert C.; McCall, Mark D.

    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.

  1. An Ac/Ds-mediated gene trap system for functional genomics in barley

    PubMed Central

    Lazarow, Katina; Lütticke, Stephanie

    2009-01-01

    Background Gene trapping is a powerful tool for gene discovery and functional genomics in both animals and plants. Upon insertion of the gene trap construct into an expressed gene, splice donor and acceptor sites facilitate the generation of transcriptional fusions between the flanking sequence and the reporter. Consequently, detection of reporter gene expression allows the identification of genes based on their expression pattern. Up to now rice is the only cereal crop for which gene trap approaches exist. In this study we describe a gene trap system in barley (Hordeum vulgare L.) based on the maize transposable elements Ac/Ds. Results We generated gene trap barley lines by crossing Ac transposase expressing plants with multiple independent transformants carrying the Ds based gene trap construct GTDsB. Upstream of the β-Glucuronidase start codon GTDsB carries splice donor and acceptor sites optimized for monocotyledonous plants. DNA blot analysis revealed GTDsB transposition frequencies of 11% and 26% in the F1 and F2 generation of gene trap lines and perpetuation of transposition activity in later generations. Furthermore, analysis of sequences flanking transposed GTDsB elements evidenced preferential insertion into expressed regions of the barley genome. We screened leaves, nodes, immature florets, pollinated florets, immature grains and seedlings of F2 plants and detected GUS expression in 51% (72/141) of the plants. Thus, reporter gene expression was found in 24 of the 28 F1 lines tested and in progeny of all GTDsB parental lines. Conclusion Due to the frequent transposition of GTDsB and the efficient expression of the GUS reporter gene, we conclude that this Ac/Ds-based gene trap system is an applicable approach for gene discovery in barley. The successful introduction of a gene trap construct optimized for monocots in barley contributes a novel functional genomics tool for this cereal crop. PMID:19178688

  2. The AC photovoltaic module is here!

    NASA Astrophysics Data System (ADS)

    Strong, Steven J.; Wohlgemuth, John H.; Wills, Robert H.

    1997-02-01

    This paper describes the design, development, and performance results of a large-area photovoltaic module whose electrical output is ac power suitable for direct connection to the utility grid. The large-area ac PV module features a dedicated, integrally mounted, high-efficiency dc-to-ac power inverter with a nominal output of 250 watts (STC) at 120 Vac, 60 H, that is fully compatible with utility power. The module's output is connected directly to the building's conventional ac distribution system without need for any dc wiring, string combiners, dc ground-fault protection or additional power-conditioning equipment. With its advantages, the ac photovoltaic module promises to become a universal building block for use in all utility-interactive PV systems. This paper discusses AC Module design aspects and utility interface issues (including islanding).

  3. Advanced Solar Power Systems

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  4. Radiated microwave power transmission system efficiency measurements

    NASA Technical Reports Server (NTRS)

    Dickinson, R. M.; Brown, W. C.

    1975-01-01

    The measured and calculated results from determining the operating efficiencies of a laboratory version of a system for transporting electric power from one point to another via a wireless free space radiated microwave beam are reported. The system's overall end-to-end efficiency as well as intermediated conversion efficiencies were measured. The maximum achieved end-to-end dc-to-ac system efficiency was 54.18% with a probable error of + or - 0.94%. The dc-to-RF conversion efficiency was measured to be 68.87% + or - 1.0% and the RF-to-dc conversion efficiency was 78.67 + or - 1.1%. Under these conditions a dc power of 495.62 + or - 3.57 W was received with a free space transmitter antenna receiver antenna separation of 170.2 cm (67 in).

  5. 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.

  6. Comparison of the Unique Mobility and DOE-developed ac electric drive systems

    SciTech Connect

    Cole, G.H.

    1993-01-01

    A comparison was made between the most recent DOE-developed AC electric vehicle drive systems and that which is independently under development by Unique Mobility of Golden, Colorado. The DOE-developed AC systems compared in this study are the Single-Shaft Electric Propulsion System (ETX-II) developed by Ford Motor Company and the General Electric Company under contract number DE-AC07-85NV10418, the Dual-Shaft Electric Propulsion (DSEP) System developed by Eaton Corporation under contract number DOE-AC08-84NV-10366, and the anticipated results of the Modular Electric Vehicle (MEV) system currently being developed by Ford and General Electric under contract number DE-AC07-90ID13019. The Unique Mobility brushless DC electric vehicle drive system represents their latest electric drive technology and is being developed in cooperation with BMW Technik Gmbh of Germany. Comparisons of specific volume, specific weight, efficiency and expected vehicle performance are made of the different systems based upon measured system performance data where available. One conclusion presented is that the Unique Mobility drive system under development with BMW appears to provide comparable performance to the AC systems studied.

  7. A PWM quadrature-booster phase shifter for ac power transmission

    SciTech Connect

    Lopes, L.A.C.; Joos, G.; Ooi, B.T.

    1997-01-01

    The conventional structures used for phase shifters employ quadrature voltage injection controlled by means of on-load tap changers that require considerable maintenance. Line-commutated thyristor structures have been proposed to replace tap changers, but problems related to filter requirements or the number of switches have limited their utilization. This paper proposes a pulse width modulation (PWM) quadrature-booster phase shifter based on a force-commutated ac controller. It offers features such as fast dynamic response, continuous variation of the phase angle with low harmonic injection, and it requires a simple power structure and can be controlled by adjusting the duty cycle of the switches. The operating principles of the proposed phase shifter are analyzed and their feasibility is demonstrated through digital simulation and experimental implementation.

  8. Theory of ac loss in power transmission cables with second generation high temperature superconductor wires

    SciTech Connect

    Clem, J. R.; Malozemoff, A. P.

    2010-02-22

    While a considerable amount of work has been done in an effort to understand ac losses in power transmission cables made of first generation high temperature superconductor (HTS) wires, use of second generation (2G) HTS wires brings in some new considerations. The high critical current density of the HTS layer in 2G wires reduces the surface superconductor hysteretic losses, for which a new formula is derived. Instead, gap and polygonal losses, flux transfer losses in imbalanced two-layer cables and ferromagnetic losses for wires with NiW substrates constitute the principal contributions. A formula for the flux transfer losses is also derived with a paramagnetic approximation for the substrate. Current imbalance and losses associated with the magnetic substrate can be minimized by orienting the substrates of the inner winding inward and the outer winding outward.

  9. Transport ac loss of elliptical thin strips with a power-law E(J) relation

    NASA Astrophysics Data System (ADS)

    Jia, Chen-Xi; Chen, Du-Xing; Li, Shuo; Fang, Jin

    2015-10-01

    The transport ac loss Q of an elliptical thin strip of critical current I c with a power-law relation E\\propto {J}n is accurately computed as a function of current amplitude I m and frequency f. The resulting Q({I}m) is normalized to q({i}m) following the Norris critical-state formula, and converted to {q}*({i}m*) at a critical frequency f c based on a transport scaling law. Having a set of {q}*({i}m*) at several values of n as a base, a general expression of {q}*({i}m*,n) is obtained, which can be used to easily calculate q({i}m) for any practical purposes.

  10. Voltage source ac-to-dc converters for high-power transmitters

    NASA Technical Reports Server (NTRS)

    Cormier, R.

    1990-01-01

    This work was done to optimize the design of the components used for the beam power supply, which is a component of the transmitters in the Deep Space Network (DSN). The major findings are: (1) the difference in regulation between a six-pulse and a twelve-pulse converter is at most 7 percent worse for the twelve-pulse converter; (2) the commutation overlap angle of a current source converter equals that of a voltage source converter with continuous line currents; (3) the sources of uncharacteristic harmonics are identified with SPICE simulation; (4) the use of an imperfect phase-shifting transformer for the twelve-pulse converter generates a harmonic at six times the line frequency; and (5) the assumptions usually made in analyzing converters can be relaxed with SPICE simulation. The results demonstrate the suitability of using SPICE simulation to obtain detailed performance predictions of ac-to-dc converters.

  11. 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.

  12. High power dc/dc and dc/ac electrical power conversion techniques developed

    NASA Technical Reports Server (NTRS)

    Berryman, G.; White, W. T.

    1967-01-01

    Small magnetic amplifiers pass square waves through transformers and provide regulation by varying the pulse width on the secondary of the output power transformers. This pulse duration modulation is provided by a control rectifier technique or a phase-shift technique.

  13. Space station power system

    NASA Technical Reports Server (NTRS)

    Forestieri, A. F.; Baraona, C. R.

    1984-01-01

    It is pointed out that space station planning at NASA began when NASA was created in 1958. However, the initiation of the program for a lunar landing delayed the implementation of plans for a space station. The utility of a space station was finally demonstrated with Skylab, which was launched in 1972. In May 1982, the Space Station Task Force was established to provide focus and direction for space station planning activities. The present paper provides a description of the planning activities, giving particular attention to the power system. The initial space station will be required to supply 75 kW of continuous electrical power, 60 kW for the customer and 15 kW for space station needs. Possible alternative energy sources for the space station include solar planar or concentrator arrays of either silicon or gallium arsenide.

  14. The dynamic process of atmospheric water sorption in [EMIM][Ac] and mixtures of [EMIM][Ac] with biopolymers and CO2 capture in these systems.

    PubMed

    Chen, Yu; Sun, Xiaofu; Yan, Chuanyu; Cao, Yuanyuan; Mu, Tiancheng

    2014-10-01

    There are mainly three findings related to the dynamic process of atmospheric water sorption in the ionic liquid (IL) 1-ethyl-3-methlyl-imidazolium acetate ([EMIM][Ac]) and its mixtures with biopolymers (i.e., cellulose, chitin, and chitosan), and CO2 capture in these systems above. The analytical methods mainly include gravimetric hygroscopicity measurement and in situ infrared spectroscopy with the techniques of difference, derivative, deconvoluted attenuated total reflectance and two-dimensional correlation. These three findings are listed as below. (1) Pure [EMIM][Ac] only shows a two-regime pattern, while all the mixtures of [EMIM][Ac] with biopolymers (i.e., cellulose, chitin, and chitosan) present a three-regime tendency for the dynamic process of atmospheric water sorption. Specifically, the IL/chitosan mixture has a clear three-regime mode; the [EMIM][Ac]/chitin mixture has an unclear indiscernible regime 3; and the [EMIM][Ac]/cellulose mixture shows an indiscernible regime 2. (2) [EMIM][Ac] and its mixtures with biopolymers could physically absorb a trace amount of and chemically react with a much larger amount of CO2 from the air. The chemisorption capacity of CO2 in these pure and mixed systems is ordered as chitosan/[EMIM][Ac] mixture > chitin/[EMIM][Ac] mixture > cellulose/[EMIM][Ac] mixture > pure [EMIM][Ac] (ca. 0.09 mass ratio % g/g CO2/IL). (3) The CO2 solubility in [EMIM][Ac] decreases about 50% after being exposed to the atmospheric moist air for some specific time period. PMID:25208304

  15. 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.

  16. Power control system and method

    DOEpatents

    Steigerwald, Robert Louis [Burnt Hills, NY; Anderson, Todd Alan [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.

  17. 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.

  18. Design of a robust modulation controller over a wide range of load characteristics for ac/dc systems

    SciTech Connect

    Choudry, M.A.; Reza, M.A. . Dept. of Electrical Engineering); Ellithy, K.A. )

    1990-02-01

    This paper presents a method to design a robust modulation controller to improve the dynamic performance of ac/dc systems. Static load is modeled as a nonlinear function of load bus voltage and dynamic load is modeled by an equivalent induction motor. Reactive power and dc power are considered for the modulation control. Static var compensator (SVC) is used for the reactive power modulation. The rotor speed and angle deviations of the synchronous generator are used as a stabilizing signal to the SVC. The controller gains are selected based on the eigenvalue sensitivity of electromechanical mode of the closed loop system with respect to load characteristic. Eigenvalue analysis and simulation results show that the proposed reactive power modulation control improves the system response over a wide range of voltage dependent load characteristic as compared with the control using only the rotor speed deviation.

  19. Space Station power system selection

    NASA Technical Reports Server (NTRS)

    Rice, R. R.

    1986-01-01

    The Space Station power system selection process is described with attention given to management organization and technical considerations. A hybrid power system was chosen because of the large life cycle cost savings. The power management and distribution system that was chosen was the 400 Hz system.

  20. Power Systems Development Facility

    SciTech Connect

    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.

  1. Reduced Toxicity Fuel Satellite Propulsion System Including Axial Thruster and ACS Thruster Combination

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J. (Inventor)

    2001-01-01

    A reduced toxicity fuel satellite propulsion system including a reduced toxicity propellant supply for consumption in an axial class thruster and an ACS class thruster. The system includes suitable valves and conduits for supplying the reduced toxicity propellant to the ACS decomposing element of an ACS thruster. The ACS decomposing element is operative to decompose the reduced toxicity propellant into hot propulsive gases. In addition the system includes suitable valves and conduits for supplying the reduced toxicity propellant to an axial decomposing element of the axial thruster. The axial decomposing element is operative to decompose the reduced toxicity propellant into hot gases. The system further includes suitable valves and conduits for supplying a second propellant to a combustion chamber of the axial thruster, whereby the hot gases and the second propellant auto-ignite and begin the combustion process for producing thrust.

  2. Power Systems Development Facility

    SciTech Connect

    Southern Company Services

    2004-04-30

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

  3. Experimental verification of fuzzy excitation control system for multi-machine power system

    SciTech Connect

    Kitauchi, Yoshihiro; Taniguchi, Haruhito

    1997-03-01

    Fuzzy excitation control system (FECS), based on Fuzzy theorem and having the function of both AVR and PSS, was established to improve power system stability. This paper includes the results of experiments of the FECS on AC/DC Power System Simulator of the CRIEPI. The FECS is compared with the conventional quick-response excitation system with optimized PSSs on a 4-machine long distance fish-bone type power system and various system configurations. The results show that the FECS increases the power transfer limit more than 20% without any parameter tuning.

  4. Power flow for spacecraft power systems

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

  5. 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.

  6. Ac traction gets on track

    SciTech Connect

    O`Connor, L.

    1995-09-01

    This article describes inverter-based ac traction systems which give freight locomotives greater adhesion, pulling power, and braking capacity. In the 1940s, dc traction replaced the steam engine as a source of train propulsion, and it has ruled the freight transportation industry ever since. But now, high-performance ac-traction systems, with their unprecedented levels of pulling power and adhesion, are becoming increasingly common on America`s freight railroads. In thousands of miles of demonstration tests, today`s ac-traction systems have outperformed traditional dc-motor driven systems. Major railroad companies are convinced enough of the benefits of ac traction to have integrated it into their freight locomotives.

  7. 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.

  8. Unified active and reactive power modulation of HVDC transmission systems

    NASA Astrophysics Data System (ADS)

    Grund, C. E.; Pohl, R. V.

    1981-11-01

    The power modulation of a high voltage direct current (HVDC) system for stabilization of an ac/dc network was investigated. It was found that simultaneous modulation of both dc current and voltage was more effective than just current modulation by itself, since the dc voltage modulation could be used to minimize the reactive power changes resulting from a change of the dc current. This helps stabilize the ac busbar voltages at the converters, which reduces undesirable load flow changes to voltage dependent ac loads, thus improving the effectiveness of the dc power modulation. This unified modulation control concept was evaluated by means of digital computer studies as well as a special purpose HVDC simulator. Several combined ac/dc power transmission systems were synthesized for testing of different modulation controller concepts. An optimum controller design incorporating a linear quadratic control algorithm with full state feedback was first studied. This provided a basis for comparison of suboptimal controller designs utilizing reduced state feedback and a Kalman filter state reconstruction technique.

  9. 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.

  10. AC conductivity and Dielectric Study of Chalcogenide Glasses of Se-Te-Ge System

    NASA Astrophysics Data System (ADS)

    Salman, Fathy

    2004-01-01

    The ac conductivity and dielectric properties of glassy system SexTe79 - xGe21, with x = 11, 14, 17 at.%, has been studied at temperatures 300 to 450 K and over a wide range of frequencies (50 Hz to 500 kHz). Experimental results indicate that the ac conductivity and the dielectric constants depend on temperature, frequency and Se content. The conductivity as a function of frequency exhibited two components: dc conductivity s dc, and ac conductivity s ac, where s ac ˜ w s. The mechanism of ac conductivity can be reasonably interpreted in terms of the correlated barrier hopping model (CBH). The activation energies are estimated and discussed. The dependence of ac conductivity and dielectric constants on the Se content x can be interpreted as the effect of Se fraction on the positional disorder. The impedance plot at each temperature appeared as a semicircle passes through the origin. Each semicircle is represented by an equivalent circuit of parallel resistance Rb and capacitance Cb.

  11. Reliable, Efficient and Cost-Effective Electric Power Converter for Small Wind Turbines Based on AC-link Technology

    SciTech Connect

    Darren Hammell; Mark Holveck; DOE Project Officer - Keith Bennett

    2006-08-01

    Grid-tied inverter power electronics have been an Achilles heel of the small wind industry, providing opportunity for new technologies to provide lower costs, greater efficiency, and improved reliability. The small wind turbine market is also moving towards the 50-100kW size range. The unique AC-link power conversion technology provides efficiency, reliability, and power quality advantages over existing technologies, and Princeton Power will adapt prototype designs used for industrial asynchronous motor control to a 50kW small wind turbine design.

  12. Onboard power line conditioning system for an electric or hybrid vehicle

    DOEpatents

    Kajouke, Lateef A.; Perisic, Milun

    2016-06-14

    A power line quality conditioning system for a vehicle includes an onboard rechargeable direct current (DC) energy storage system and an onboard electrical system coupled to the energy storage system. The energy storage system provides DC energy to drive an electric traction motor of the vehicle. The electrical system operates in a charging mode such that alternating current (AC) energy from a power grid external to the vehicle is converted to DC energy to charge the DC energy storage system. The electrical system also operates in a vehicle-to-grid power conditioning mode such that DC energy from the DC energy storage system is converted to AC energy to condition an AC voltage of the power grid.

  13. 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.

  14. Proposal of Current Control Method for High-Speed AC Motor System

    NASA Astrophysics Data System (ADS)

    Furutani, Shinichi; Satake, Akira

    In this paper, current control method for High-Speed AC Motor System is proposed. In High-Speed driving operation, Current controller tends to lose stability because of dead time caused by computational delay and Electromagnetic coupling included AC Motor Model. The Main purpose of the proposed method is reduction of dead time on current controller. Proposed method based model predictive control and optimizing of start timing. The Effectiveness of proposed method is confirmed by simulation results.

  15. Power Quality Control and Design of Power Converter for Variable-Speed Wind Energy Conversion System with Permanent-Magnet Synchronous Generator

    PubMed Central

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%. PMID:24453905

  16. Power quality control and design of power converter for variable-speed wind energy conversion system with permanent-magnet synchronous generator.

    PubMed

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%. PMID:24453905

  17. Simple uniaxial pressure device for ac-susceptibility measurements suitable for closed cycle refrigerator system.

    PubMed

    Arumugam, S; Manivannan, N; Murugeswari, A

    2007-06-01

    A simple design of the uniaxial pressure device for the measurement of ac-susceptibility at low temperatures using closed cycle refrigerator system is presented for the first time. This device consists of disc micrometer, spring holder attachment, uniaxial pressure cell, and the ac-susceptibility coil wound on stycast bobbin. It can work under pressure till 0.5 GPa and at the temperature range of 30-300 K. The performance of the system at ambient pressure is tested and calibrated with standard paramagnetic salts [Gd(2)O(3), Er(2)O(3), and Fe(NH(4)SO(4))(2)6H(2)O], Fe(3)O(4), Gd metal, Dy metal, superconductor (YBa(2)Cu(3)O(7)), manganite (La(1.85)Ba(0.15)MnO(3)), and spin glass material (Pr(0.8)Sr(0.2)MnO(3)). The performance of the uniaxial pressure device is demonstrated by investigating the uniaxial pressure dependence of La(1.85)Ba(0.15)MnO(3) single crystal with P||c axis. The Curie temperature (T(c)) decreases as a function of pressure with P||c axis (dT(c)dP(||c axis)=-11.65 KGPa) up to 46 MPa. The design is simple, is user friendly, and does not require pressure calibration. Measurement can even be made on thin and small size oriented crystals. The failure of the coil is remote under uniaxial pressure. The present setup can be used as a multipurpose uniaxial pressure device for the measurement of Hall effect and thermoelectric power with a small modification in the pressure cell. PMID:17614625

  18. New power-conditioning systems for superconducting magnetic energy storage

    NASA Astrophysics Data System (ADS)

    Han, Byung Moon

    1992-06-01

    This dissertation presents the development of new power-conditioning systems for superconducting magnetic energy storage (SMES), which can regulate fast and independently the active and reactive powers demanded in the ac network. Three new power-conditioning systems were developed through a systematic approach to match the requirements of the superconducting coil and the ac power network. Each of these new systems is composed of ten 100-MW modules connected in parallel to handle the large current through the superconducting coil. The first system, which was published in the IEEE Transactions on Energy Conversion, consists of line-commutated 24-pulse converter, a thyristor-switched tap-changing transformer, and a thyristor-switched capacitor bank. The second system, which was accepted for publication in the IEEE Transactions on Energy Conversion, consists of a 12-pulse GTO (gate turn-off thyristor) converter and a thyristor-switched tap-changing transformer. The third system, which was submitted to the International Journal of Energy System, consists of a dc chopper and a voltage-source PWM (pulse width modulation) converter. The operational concept of each new system is verified through mathematical analyses and computer simulations. The dynamic interaction of each new system with the ac network and the superconducting coil is analyzed using a simulation model with EMTP (electro-magnetic transients program). The analysis results prove that each new system is feasible and realizable. Each system can regulate the active and reactive powers of the utility network rapidly and independently, and each offer a significant reduction of the system rating by reducing the reactive power demand in the converter. Feasible design for each new system was introduced using a modular design approach based on the 1000 MW/5000 MWH plant, incorporating commercially available components and proven technologies.

  19. Depinning of flux lines and AC losses in magnet-superconductor levitation system

    SciTech Connect

    Terentiev, A. N.; Hull, J. R.; De Long, L. E.

    1999-11-29

    The AC loss characteristics of a magnet-superconductor system were studied with the magnet fixed to the free end of an oscillating cantilever located near a stationary melt-textured YBCO pellet. Below a threshold AC field amplitude {approx}2Oe, the dissipation of the oscillator is amplitude-independent, characteristic of a linear, non-hysteretic regime. Above threshold,dissipation increases with amplitude, reflecting the depinning and hysteretic motion of flux lines. The threshold AC field is an order of magnitude higher than that measured for the same YBCO material via AC susceptometry in a uniform DC magnetic field, A partial lock-in of flux lines between YBCO ab planes is proposed as the mechanism for the substantial increase of the depinning threshold.

  20. Marketing information system online design for craftsmen small medium enterprises (case study: craftsmen ac)

    NASA Astrophysics Data System (ADS)

    Fitriana, Rina; Kurniawan, Wawan; Barlianto, Anung; Adriansyah Putra, Rizki

    2016-02-01

    AC is small and medium enterprises which is engaged in the field of crafts. This SME (Small Medium Enterprise) didn't have an integrated information system for managing sales. This research aims to design a marketing Information system online as applications that built as web base. The integrated system is made to manage sales and expand its market share. This study uses a structured analysis and design in its approach to build systems and also implemented a marketing framework of STP (Segmentation, Targeting, Positioning) and 4P (Price, Product, Place, Promotion) to obtain market analysis. The main market target customer craftsmen AC is women aged 13 years to 35 years. The products produced by AC are shoes, brooch, that are typical of the archipelago. The prices is range from Rp. 2000 until Rp. 400.000. Marketing information system online can be used as a sales transaction document, promoting the goods, and for customer booking products.

  1. AC electrokinetic drug delivery in dentistry using an interdigitated electrode assembly powered by inductive coupling.

    PubMed

    Ivanoff, Chris S; Wu, Jie Jayne; Mirzajani, Hadi; Cheng, Cheng; Yuan, Quan; Kevorkyan, Stepan; Gaydarova, Radostina; Tomlekova, Desislava

    2016-10-01

    AC electrokinetics (ACEK) has been shown to deliver certain drugs into human teeth more effectively than diffusion. However, using electrical wires to power intraoral ACEK devices poses risks to patients. The study demonstrates a novel interdigitated electrode arrays (IDE) assembly powered by inductive coupling to induce ACEK effects at appropriate frequencies to motivate drugs wirelessly. A signal generator produces the modulating signal, which multiplies with the carrier signal to produce the amplitude modulated (AM) signal. The AM signal goes through the inductive link to appear on the secondary coil, then rectified and filtered to dispose of its carrier signal, and the positive half of the modulating signal appears on the load. After characterizing the device, the device is validated under light microscopy by motivating carboxylate-modified microspheres, tetracycline, acetaminophen, benzocaine, lidocaine and carbamide peroxide particles with induced ACEK effects. The assembly is finally tested in a common dental bleaching application. After applying 35 % carbamide peroxide to human teeth topically or with the IDE at 1200 Hz, 5 Vpp for 20 min, spectrophotometric analysis showed that compared to diffusion, the IDE enhanced whitening in specular optic and specular optic excluded modes by 215 % and 194 % respectively. Carbamide peroxide absorbance by the ACEK group was two times greater than diffusion as measured by colorimetric oxidation-reduction and UV-Vis spectroscopy at 550 nm. The device motivates drugs of variable molecular weight and structure wirelessly. Wireless transport of drugs to intraoral targets under ACEK effects may potentially improve the efficacy and safety of drug delivery in dentistry. PMID:27565821

  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. Optical power distribution system

    SciTech Connect

    Lalmond, R.G.

    1987-09-08

    This patent describes an apparatus for supplying electrical power to electrical components mounted on a circuit board. It consists of: a printed circuit board; electrical components mounted on the printed circuit board; electrically powered sources of optical energy; photovoltaic cell arrays; each photovoltaic cell array being mounted on a corresponding one of the electrical components to provide electrical power to the electrical component on which it is mounted; and means for coupling the optical energy from the electrically powered sources of optical energy to the photovoltaic cell arrays.

  4. Pluto Express power system architecture

    SciTech Connect

    Carr, G.A.

    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.

  5. Pulse doubling in zigzag-connected autotransformer-based 12-pulse ac-dc converter for power quality improvement

    NASA Astrophysics Data System (ADS)

    Abdollahi, Rohollah

    2012-12-01

    This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMDs) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse acdc converters each of them consisting of three-phase diode bridge rectifiers. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads.

  6. 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

  7. Study of the DEF Feedback Control System in AC Operation of Superconducting Tokamak

    NASA Astrophysics Data System (ADS)

    Wang, Hua; Luo, Jiarong; Yuan, Qiping; Xu, Congdong

    2007-02-01

    AC operation with multiple full cycles has been successfully performed on the superconducting tokamak HT-7. In the experiment, it was discovered that the saturation of the transformer magnetic flux with DEF, a signal name, was one of key aspects that affected the AC operation. The conditions of DEF were examined through the DEF feedback control system. By controlling the working patterns of the subsystems, namely the poloidal field control system and density control system, it was guaranteed that DEF would remain in the non-saturated status.

  8. ac bidirectional motor controller

    NASA Technical Reports Server (NTRS)

    Schreiner, K.

    1988-01-01

    Test data are presented and the design of a high-efficiency motor/generator controller at NASA-Lewis for use with the Space Station power system testbed is described. The bidirectional motor driver is a 20 kHz to variable frequency three-phase ac converter that operates from the high-frequency ac bus being designed for the Space Station. A zero-voltage-switching pulse-density-modulation technique is used in the converter to shape the low-frequency output waveform.

  9. 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.

  10. Switching power pulse system

    DOEpatents

    Aaland, Kristian

    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.

  11. 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.

  12. Autonomous power system: Integrated scheduling

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.

    1992-01-01

    The Autonomous Power System (APS) project at NASA Lewis Research Center is designed to demonstrate the abilities of integrated intelligent diagnosis, control and scheduling techniques to space power distribution hardware. The project consists of three elements: the Autonomous Power Expert System (APEX) for fault diagnosis, isolation, and recovery (FDIR), the Autonomous Intelligent Power Scheduler (AIPS) to determine system configuration, and power hardware (Brassboard) to simulate a space-based power system. Faults can be introduced into the Brassboard and in turn, be diagnosed and corrected by APEX and AIPS. The Autonomous Intelligent Power Scheduler controls the execution of loads attached to the Brassboard. Each load must be executed in a manner that efficiently utilizes available power and satisfies all load, resource, and temporal constraints. In the case of a fault situation on the Brassboard, AIPS dynamically modifies the existing schedule in order to resume efficient operation conditions. A database is kept of the power demand, temporal modifiers, priority of each load, and the power level of each source. AIPS uses a set of heuristic rules to assign start times and resources to each load based on load and resource constraints. A simple improvement engine based upon these heuristics is also available to improve the schedule efficiency. This paper describes the operation of the Autonomous Intelligent Power Scheduler as a single entity, as well as its integration with APEX and the Brassboard. Future plans are discussed for the growth of the Autonomous Intelligent Power Scheduler.

  13. Space solar power systems

    NASA Technical Reports Server (NTRS)

    Toliver, C.

    1977-01-01

    Studies were done on the feasibility of placing a solar power station called POwersat, in space. A general description of the engineering features are given as well as a brief discussion of the economic considerations.

  14. Power System State of Health

    NASA Astrophysics Data System (ADS)

    Carpenter, P.

    2012-12-01

    Understanding the state of a polar station's power system can be critical to a successful long-term deployment. Knowing how the system is functioning, prior to service, is key to proper logistics, scheduling and the service performed during a visit. A full record of power system performance is key to proper analysis of the health of the power system. The design of a power system with monitoring is a balance of components to gather information while still trying to keep complexity low. To properly incorporate a system to analyze a stations power system a firm understanding of how the power components function in polar environments as well as communication to data acquisition and / or telemetry is needed. For example designers will need to know how a station's power storage system will change in colder environments then manufactures standard design criteria. This would include the reduced available capacity, change in the mean time between failure and possible new failure modes. This understanding coupled with a system that would collect key information on the state of health of the power system will provide crucial insight in to what service is needed to keep the station functioning.

  15. Alpha Power Increase After Transcranial Alternating Current Stimulation at Alpha Frequency (α-tACS) Reflects Plastic Changes Rather Than Entrainment

    PubMed Central

    Vossen, Alexandra; Gross, Joachim; Thut, Gregor

    2015-01-01

    Background Periodic stimulation of occipital areas using transcranial alternating current stimulation (tACS) at alpha (α) frequency (8–12 Hz) enhances electroencephalographic (EEG) α-oscillation long after tACS-offset. Two mechanisms have been suggested to underlie these changes in oscillatory EEG activity: tACS-induced entrainment of brain oscillations and/or tACS-induced changes in oscillatory circuits by spike-timing dependent plasticity. Objective We tested to what extent plasticity can account for tACS-aftereffects when controlling for entrainment “echoes.” To this end, we used a novel, intermittent tACS protocol and investigated the strength of the aftereffect as a function of phase continuity between successive tACS episodes, as well as the match between stimulation frequency and endogenous α-frequency. Methods 12 healthy participants were stimulated at around individual α-frequency for 11–15 min in four sessions using intermittent tACS or sham. Successive tACS events were either phase-continuous or phase-discontinuous, and either 3 or 8 s long. EEG α-phase and power changes were compared after and between episodes of α-tACS across conditions and against sham. Results α-aftereffects were successfully replicated after intermittent stimulation using 8-s but not 3-s trains. These aftereffects did not reveal any of the characteristics of entrainment echoes in that they were independent of tACS phase-continuity and showed neither prolonged phase alignment nor frequency synchronization to the exact stimulation frequency. Conclusion Our results indicate that plasticity mechanisms are sufficient to explain α-aftereffects in response to α-tACS, and inform models of tACS-induced plasticity in oscillatory circuits. Modifying brain oscillations with tACS holds promise for clinical applications in disorders involving abnormal neural synchrony. PMID:25648377

  16. Systems view of power systems autonomy

    SciTech Connect

    Anderson, J.L.

    1984-08-01

    A space station will involve the formation and sustained operation of an assembly of humans and machines in space for a period of 10-20 years. Technology and mission studies of a permanently manned, evolutionary space station have identified the need for automated and eventually some degree of autonomous systems operation. A space station power system will have a high degree of interaction with other onboard systems which will act as power loads. By examining the evolution of an operational power system from a systems viewpoint through increasing degrees of automation the system and technology requirements are identified for an evolutionary system.

  17. 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.

  18. Advanced Power System Analysis Capabilities

    NASA Technical Reports Server (NTRS)

    1997-01-01

    As a continuing effort to assist in the design and characterization of space power systems, the NASA Lewis Research Center's Power and Propulsion Office developed a powerful computerized analysis tool called System Power Analysis for Capability Evaluation (SPACE). This year, SPACE was used extensively in analyzing detailed operational timelines for the International Space Station (ISS) program. SPACE was developed to analyze the performance of space-based photovoltaic power systems such as that being developed for the ISS. It is a highly integrated tool that combines numerous factors in a single analysis, providing a comprehensive assessment of the power system's capability. Factors particularly critical to the ISS include the orientation of the solar arrays toward the Sun and the shadowing of the arrays by other portions of the station.

  19. Photovoltaic power system reliability considerations

    NASA Technical Reports Server (NTRS)

    Lalli, V. R.

    1980-01-01

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

  20. MYRIADE Power System In Flight

    NASA Astrophysics Data System (ADS)

    Elisabelar, C.; Fredon, S.

    2011-10-01

    This paper presents the after performance of the power system during more than 6 years in orbit on the 6 first MYRIADE microsatellites launched in 2004: DEMETER, PARASOL and the 4 ESSAIMs. Results on the last CNES MYRIADE mission PICARD which was launched in June 2010 are also presented. First of all a description of the power system and its operation on the different missions is made. The evolutions and degradations of the main power sources : solar generator, battery are presented. Flight performances are compared with prediction by using different methods. In conclusion a synthesis on the power system performance is made and a feedback for future MYRIADE developments is proposed.

  1. AC Servo Motor Based Position Sensorless Control System Making Use of Springs

    NASA Astrophysics Data System (ADS)

    Shimada, Akira; Kishiwada, Yu; Arimura, Michiyo

    This paper describes a position sensorless control technique on AC servo motor based position control systems. Shimada et al. had previously presented a paper on a DC servo motor based position sensorless control technique using mechanical springs. It was based on a point of view that mechanical springs form the key components for the observability. On the basis of the result obtained from the successful experiment, we assumed that the AC servo motor position sensorless control system would be identical. Using vector control, the controller needs the data of the magnetic pole position on the rotor of the AC servo motor. It is not perfect sensorless control, since it use a rotary encoder. However, we introduce it and demonstrate the expreimental results as an initial step in the new control technology.

  2. A low power on-chip class-E power amplifier for remotely powered implantable sensor systems

    NASA Astrophysics Data System (ADS)

    Ture, Kerim; Kilinc, Enver G.; Dehollain, Catherine

    2015-06-01

    This paper presents a low power fully integrated class-E power amplifier and its integration with remotely powered sensor system. The class-E power amplifier is suitable solution for low-power applications due to its high power efficiency. However, the required high inductance values which make the on-chip integration of the power amplifier difficult. The designed power amplifier is fully integrated in the remotely powered sensor system and fabricated in 0.18 μm CMOS process. The power is transferred to the implantable sensor system at 13.56 MHz by using an inductively coupled remote powering link. The induced AC voltage on the implant coil is converted into a DC voltage by a passive full-wave rectifier. A voltage regulator is used to suppress the ripples and create a clean and stable 1.8 V supply voltage for the sensor and communication blocks. The data collected from the sensors is transmitted by on-off keying modulated low-power transmitter at 1.2 GHz frequency. The transmitter is composed of a LC tank oscillator and a fully on-chip class-E power amplifier. An additional output network is used for the power amplifier which makes the integration of the power amplifier fully on-chip. The integrated power amplifier with 0.2 V supply voltage has a drain efficiency of 31.5% at -10 dBm output power for 50 Ω load. The measurement results verify the functionality of the power amplifier and the remotely powered implantable sensor system. The data communication is also verified by using a commercial 50 Ω chip antenna and has 600 kbps data rate at 1 m communication distance.

  3. 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.

  4. Maintenance of photovoltaic power systems

    NASA Astrophysics Data System (ADS)

    Hall, M. R.

    1984-08-01

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

  5. Maintenance of photovoltaic power systems

    SciTech Connect

    Hall, M.R.

    1984-08-01

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

  6. Laser power conversion system analysis

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Orbit to orbit and orbit to ground laser power conversion systems and power transfer are discussed. A system overview is presented. Pilot program parameters are considered: SLPS assumptions are listed, a laser SPS overview is presented, specifications are listed, and SLPS coats are considered.

  7. Observer-based higher order sliding mode control of power factor in three-phase AC/DC converter for hybrid electric vehicle applications

    NASA Astrophysics Data System (ADS)

    Liu, Jianxing; Laghrouche, Salah; Wack, Maxime

    2014-06-01

    In this paper, a full-bridge boost power converter topology is studied for power factor control, using output higher order sliding mode control. The AC/DC converters are used for charging the battery and super-capacitor in hybrid electric vehicles from the utility. The proposed control forces the input currents to track the desired values, which can control the output voltage while keeping the power factor close to one. Super-twisting sliding mode observer is employed to estimate the input currents and load resistance only from the measurement of output voltage. Lyapunov analysis shows the asymptotic convergence of the closed-loop system to zero. Multi-rate simulation illustrates the effectiveness and robustness of the proposed controller in the presence of measurement noise.

  8. Limits to power system growth

    SciTech Connect

    Slater, S.M.; Klein, A.C. ); Webb, B.J. ); Pauley, K.A. )

    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.

  9. Reactive power compensating system

    DOEpatents

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

    1987-01-01

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

  10. Reactive Power Compensating System.

    DOEpatents

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

    1985-01-04

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

  11. Electrical power systems for Mars

    NASA Technical Reports Server (NTRS)

    Giudici, Robert J.

    1986-01-01

    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.

  12. Maximum Power Point Regulator System

    NASA Astrophysics Data System (ADS)

    Simola, J.; Savela, K.; Stenberg, J.; Tonicello, F.

    2011-10-01

    The target of the study done under the ESA contract No.17830/04/NL/EC (GSTP4) for Maximum Power Point Regulator System (MPPRS) was to investigate, design and test a modular power system (a core PCU) fulfilling requirement for maximum power transfer even after a single failure in the Power System by utilising a power concept without any potential and credible single point failure. The studied MPPRS concept is of a modular construction, able to track the MPP individually on each SA sections, maintaining its functionality and full power capability after a loss of a complete MPPR module (by utilizingN+1module).Various add-on DCDC converter topology candidates were investigated and redundancy, failure mechanisms and protection aspects were studied

  13. 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.

  14. Power system state estimation for a spacecraft power system

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  15. Power system stability

    SciTech Connect

    Not Available

    1984-03-01

    The following papers are included: exact Lagrangians for linear nonconservative systems; linear nonconservative systems with asymmetric parameters derivable from a Lagrangian; some remarks on the derivability of linear nonconservative systems from a Lagrangian; dynamic response by means of functions of matrices; a direct construction of first integrals for certain nonlinear dynamical systems; derivation of the Brayton-Moser equations from a topological mixed potential function; quadratic integrals for linear nonconservative systems and their connection with the inverse problem of Lagrangian dynamics; generalized Lagrangian and conservation law for the damped harmonic oscillator; connections between the generalized Hamilton-Lagrange and Brayton-Moser equations; time-dependent linear systems derivable from a variational principle; the generalized Lagrange formulation for nonlinear RLC networks; the Helmholtz conditions revisited - a new approach to the inverse problem of Lagrangian dynamics; time-dependent linear systems derivable from a variational principle II; and conservation laws for some separable gyroscopic dynamical systems.

  16. Space power systems technology

    NASA Technical Reports Server (NTRS)

    Coulman, George A.

    1994-01-01

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

  17. Space Station power system options

    SciTech Connect

    Baraona, C.R.; Forestieri, A.F.

    1984-08-01

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

  18. Characterization of combined power plasma jet using AC high voltage and nanosecond pulse for reactive species composition control

    NASA Astrophysics Data System (ADS)

    Takashima, Keisuke; Konishi, Hideaki; Kato, Toshiaki; Kaneko, Toshiro

    2014-10-01

    In the application studies for both bio-medical and agricultural applications, the roles of the reactive oxide and/or nitride species generated in the plasma has been reported as a key to control the effects and ill-effects on the living organism. The correlation between total OH radical exposure from an air atmospheric pressure plasma jet and the sterilization threshold on Botrytis cinerea is presented. With the increase of the OH radical exposure to the Botrytis cinerea, the probability of sterilization is increased. In this study, to resolve the roles of reactive species including OH radicals, a combined power plasma jet using nanosecond pulses and low-frequency sinusoidal AC high voltage (a few kHz) is studied for controlling the composition of the reactive species. The nanosecond pulses are superimposed on the AC voltage which is in synchronization with the AC phase. The undergoing work to characterize the combined power discharge with electric charge and voltage cycle on the plasma jet will also be presented to discuss the discharge characteristics to control the composition of the reactive species.

  19. Development of New Type Gap Arrester for Earth Fault Protection in AC Feeding System

    NASA Astrophysics Data System (ADS)

    Ajiki, Kohji; Morimoto, Hiroaki; Hisamizu, Yasuzi; Kinoshita, Nobuo; Takai, Wataru; Sato, Ryogo

    A gap arrester is being used for ground fault protection in AC Feeding System. However there are faults in which a conventional gap arrester burns down in a normal state of circuit. We investigated the cause of the fault in which a gap arrester burns. Then, it was found out that the cause of the fault was the discharge of AC current from the surge voltage. Therefore, we developed a new type gap arrester which does not burn down. The new type gap arrester is composed of a discharge tube and a zinc oxide element which are connected in series. Unnecessary AC current discharge is prevented by this structure. The new type gap arrester is actually used at the railroad track.

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

    NASA Astrophysics Data System (ADS)

    Mohamed, Ahmed

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

  1. High Power Alternator Test Unit (ATU) Electrical System Test

    NASA Technical Reports Server (NTRS)

    Birchenough, Arthur; Hervol, David

    2007-01-01

    The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, OH was used to simulate the operating conditions and evaluate the performance of the ATU and it s interaction with various LPSF components in accordance with the JIMO AC Power System Requirements. The testing was carried out at the breadboard development level. Results of these tests will be used for the development and validation of analytical models for performance and lifetime prediction.

  2. Shunt regulation electric power system

    NASA Technical Reports Server (NTRS)

    Wright, W. H.; Bless, J. J. (Inventor)

    1971-01-01

    A regulated electric power system having load and return bus lines is described. A plurality of solar cells interconnected in a power supplying relationship and having a power shunt tap point electrically spaced from the bus lines is provided. A power dissipator is connected to the shunt tap point and provides for a controllable dissipation of excess energy supplied by the solar cells. A dissipation driver is coupled to the power dissipator and controls its conductance and dissipation and is also connected to the solar cells in a power taping relationship to derive operating power therefrom. An error signal generator is coupled to the load bus and to a reference signal generator to provide an error output signal which is representative of the difference between the electric parameters existing at the load bus and the reference signal generator. An error amplifier is coupled to the error signal generator and the dissipation driver to provide the driver with controlling signals.

  3. System and method for monitoring and controlling stator winding temperature in a de-energized AC motor

    DOEpatents

    Lu, Bin; Luebke, Charles John; Habetler, Thomas G.; Zhang, Pinjia; Becker, Scott K.

    2011-12-27

    A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings.

  4. Power systems for future missions

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  5. Power generation systems and methods

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  6. Power turbine ventilation system

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  7. Power system applications of fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Johnston, A. R.; Jackson, S. P.; Kirkham, H.; Yeh, C.

    1986-06-01

    This document is a progress report of work done in 1985 on the Communications and Control for Electric Power Systems Project at the Jet Propulsion Laboratory. These topics are covered: Electric Field Measurement, Fiber Optic Temperature Sensing, and Optical Power transfer. Work was done on the measurement of ac and dc electric fields. A prototype sensor for measuring alternating fields was made using a very simple electroscope approach. An electronic field mill sensor for dc fields was made using a fiber optic readout, so that the entire probe could be operated isolated from ground. There are several instances in which more precise knowledge of the temperature of electrical power apparatus would be useful. This report describes a number of methods whereby the distributed temperature profile can be obtained using a fiber optic sensor. The ability to energize electronics by means of an optical fiber has the advantage that electrical isolation is maintained at low cost. In order to accomplish this, it is necessary to convert the light energy into electrical form by means of photovoltaic cells. JPL has developed an array of PV cells in gallium arsenide specifically for this purpose. This work is described.

  8. Power system applications of fiber optic sensors

    NASA Technical Reports Server (NTRS)

    Johnston, A. R.; Jackson, S. P.; Kirkham, H.; Yeh, C.

    1986-01-01

    This document is a progress report of work done in 1985 on the Communications and Control for Electric Power Systems Project at the Jet Propulsion Laboratory. These topics are covered: Electric Field Measurement, Fiber Optic Temperature Sensing, and Optical Power transfer. Work was done on the measurement of ac and dc electric fields. A prototype sensor for measuring alternating fields was made using a very simple electroscope approach. An electronic field mill sensor for dc fields was made using a fiber optic readout, so that the entire probe could be operated isolated from ground. There are several instances in which more precise knowledge of the temperature of electrical power apparatus would be useful. This report describes a number of methods whereby the distributed temperature profile can be obtained using a fiber optic sensor. The ability to energize electronics by means of an optical fiber has the advantage that electrical isolation is maintained at low cost. In order to accomplish this, it is necessary to convert the light energy into electrical form by means of photovoltaic cells. JPL has developed an array of PV cells in gallium arsenide specifically for this purpose. This work is described.

  9. Development of Low-Frequency AC Voltage Measurement System Using Single-Junction Thermal Converter

    NASA Astrophysics Data System (ADS)

    Amagai, Yasutaka; Nakamura, Yasuhiro

    Accurate measurement of low-frequency AC voltage using a digital multimeter at frequencies of 4-200Hz is a challenge in the mechanical engineering industry. At the National Metrology Institute of Japan, we developed a low-frequency AC voltage measurement system for calibrating digital multimeters operating at frequencies down to 1 Hz. The system uses a single-junction thermal converter and employs a theoretical model and a three-parameter sine wave fitting algorithm based on the least-square (LS) method. We calibrated the AC voltage down to 1Hz using our measurement system and reduced the measurement time compared with that using thin-film thermal converters. Our measurement results are verified by comparison with those of a digital sampling method using a high-resolution analog-to-digital converter; our data are in agreement to within a few parts in 105. Our proposed method enables us to measure AC voltage with an uncertainty of 25 μV/V (k = 1) at frequencies down to 4 Hz and a voltage of 10 V.

  10. Electric-Power System Simulator

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  11. Fault diagnosis of power systems

    SciTech Connect

    Sekine, Y. ); Akimoto, Y. ); Kunugi, M. )

    1992-05-01

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

  12. A/C Interface: Expert Systems: Part II.

    ERIC Educational Resources Information Center

    Dessy, Raymond E., Ed.

    1984-01-01

    Discusses working implementations of artificial intelligence systems for chemical laboratory applications. They include expert systems for liquid chromatography, spectral analysis, instrument control of a totally computerized triple-quadrupole mass spectrometer, and the determination of the mineral constituents of a rock sample given the powder…

  13. Powerful Midwest Storm System

    NASA Video Gallery

    This animation of imagery from NOAA’s GOES-13 satellite shows themovement of storm systems in the south central United States on May 20,2013. Warm, moist gulf air flowing across Texas, Oklahoma...

  14. Power enhanced frequency conversion system

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  15. Fossil power plant systems description

    SciTech Connect

    Not Available

    1984-01-01

    This single-volume, looseleaf text presents the functions and relationships between each major component and its auxiliaries within a system. The text also describes the relationships between systems. All major components are addressed, and system boundaries are defined for a generic fossil power plant.

  16. Power Systems Advanced Research

    SciTech Connect

    California Institute of Technology

    2007-03-31

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

  17. PRESSURIZED SOLID OXIDE FUEL CELL/GAS TURBINE POWER SYSTEM

    SciTech Connect

    W.L. Lundberg; G.A. Israelson; R.R. Moritz; S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann

    2000-02-01

    Power systems based on the simplest direct integration of a pressurized solid oxide fuel cell (SOFC) generator and a gas turbine (GT) are capable of converting natural gas fuel energy to electric power with efficiencies of approximately 60% (net AC/LHV), and more complex SOFC and gas turbine arrangements can be devised for achieving even higher efficiencies. The results of a project are discussed that focused on the development of a conceptual design for a pressurized SOFC/GT power system that was intended to generate 20 MWe with at least 70% efficiency. The power system operates baseloaded in a distributed-generation application. To achieve high efficiency, the system integrates an intercooled, recuperated, reheated gas turbine with two SOFC generator stages--one operating at high pressure, and generating power, as well as providing all heat needed by the high-pressure turbine, while the second SOFC generator operates at a lower pressure, generates power, and provides all heat for the low-pressure reheat turbine. The system cycle is described, major system components are sized, the system installed-cost is estimated, and the physical arrangement of system components is discussed. Estimates of system power output, efficiency, and emissions at the design point are also presented, and the system cost of electricity estimate is developed.

  18. Roof sprinkling system sweats down A/C costs

    SciTech Connect

    Not Available

    1984-05-01

    This article describes a roof spray system which enhances the energy efficiency of a building's HVAC system at a nominal cost in relationship to the benefits it yields. Roof spray cooling is based on the fact that water, when it evaporates, absorbs large amounts of heat. The evaporation of one gallon of water will dissipate about 8500 BTU's of heat; and three fallons of water evaporated over one hour's time offers the same cooling capacity as a two-ton airconditioner operated over the same period. By intermittently spraying its surface with water, a direct evaporative cooling system allows a roof to sweat away the sun's radiant heat, cooling an un-airconditioned building from 10 to 12 degrees mrt and reducing summer electric costs by 25%.

  19. Underground home A/C system. Final report

    SciTech Connect

    Outland, B.W.

    1981-06-30

    The purpose of the project was to transfer the heat of house air into the earth through an underground piping system, return the cooler to the house and disperse it throughout the house. The principle of the idea has been achieved, but not to the extent desired. It was originally hoped that the system would allow temperatures in the house to reach a maximum of 80/sup 0/ even during days where outside temperatures reached high 90/sup 0/. So far, a differential of 6/sup 0/ to 8/sup 0/ has been achieved.

  20. Design considerations for large space electric power systems

    NASA Technical Reports Server (NTRS)

    Renz, D. D.; Finke, R. C.; Stevens, N. J.; Triner, J. E.; Hansen, I. G.

    1983-01-01

    As power levels of spacecraft rise to the 50 to 100 kW range, it becomes apparent that low voltage (28 V) dc power distribution and management systems will not operate efficiently at these higher power levels. The concept of transforming a solar array voltage at 150 V dc into a 1000 V ac distribution system operating at 20 kHz is examined. The transformation is accomplished with series-resonant inverter by using a rotary transformer to isolate the solar array from the spacecraft. The power can then be distributed in any desired method such as three phase delta to delta. The distribution voltage can be easily transformed to any desired load voltage and operating frequency. The reasons for the voltage limitations on the solar array due to plasma interactions and the many advantages of a high voltage, high frequency at distribution system are discussed.

  1. 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

  2. Beam Diagnostics Based on AC Modulation of System Parameters

    SciTech Connect

    Michael Tiefenback

    2004-11-10

    To improve the performance of operating accelerators, quantities such as lattice functions, beam transfer functions, betatron frequencies, etc, can be measured turn by turn with beam position monitors or from difference measurements using step changes in system parameters. Spectral measurements in closed orbit machines provide accurate values for some properties. But for open-ended systems and some measurements in closed-orbit machines, periodic modulation can be very useful for obtaining information about the beam line. Using examples from existing machines, we compare and contrast beam based modulation techniques and step function or passive measurements. For example, large amplitude dipole modulation in rings can be used in dedicated exploration of nonlinear optical properties without beam degradation, even allowing for tune spread effects. Low-level modulation can provide real-time system monitoring with no adverse effect on beam users. Examples considered include fully resonant dipole modulation in storage rings such as RHIC (hadrons) and PEP-II (electrons), and the continuous low-level modulation used in the CEBAF recirculating electron linac for real-time feedback to improve availability.

  3. Solar power generating system

    SciTech Connect

    Watson, J.C.

    1981-08-18

    A volatile liquid is circulated through a normally closed circuit, including expansion tubes within an expansion chamber where the sun's rays are focused on the tubes to heat the liquid, transforming it to an expanding gas to drive a fluid-operated motor, also in the circuit. The motor may drive a mechanical load or an electric generator. The generator drives a pump which compresses the gas back to a liquid state and returns the same to a reservoir and to the inlets of the expansion tubes in the expansion chamber. An air reservoir which is pressurized by a pump driven by the fluid operated motor has its outlet connected to the motor inlet so that during periods of darkness or cloud cover in which the volatile liquid is not expanded into a gas, the pressurized air will be automatically fed into the motor to continue to drive the same. A gimbal system automatically controlled by sun tracking devices supports the expansion chamber to continually focus the sun's rays onto the expansion tubes, regardless of the relative position of the sun and the base on which the gimbal system is mounted.

  4. Solar-Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  5. 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.

  6. An evaluation of the Panasonic model UD513AC-1 Thermoluminescence Dosimetry system

    SciTech Connect

    Durrer, R.E. Jr.

    1991-12-01

    An evaluation of the Panasonic UD513AC-1 Thermoluminescence Dosimetry system was performed to determine the system`s capabilities as a general purpose thermoluminescence dosimeter measuring device. The tests that were performed included a critique of the user`s manual, delimitation of the operating parameters, the quality of construction, and an evaluation of the features that were unique to this system. The UD513AC-1 was found to be an adequate measuring device for most dosimetric applications. It was not well suited for experimental work with thermoluminescence materials due to a low sensitivity displayed by the photomultiplier tube to commonly used materials. The system was well constructed and did not suffer hardware failure during this research. Major attributes of the UD513AC-1 were automatic data storage, highly reproducible heating ramps, an excellent infrared light filter and a unique feature to a single phosphor unit, a dose determination function. Negative aspects of the system included a limited data manipulation capability within the controlling program, a poorly written user`s manual, inadequate sensitivity on the part of the photomultiplier tube, and insufficient capability to adjust the hot N{sub 2} gas flow to desired levels.

  7. Power system interface and umbilical system study

    NASA Technical Reports Server (NTRS)

    1980-01-01

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

  8. Harmonic analysis of spacecraft power systems using a personal computer

    NASA Technical Reports Server (NTRS)

    Williamson, Frank; Sheble, Gerald B.

    1989-01-01

    The effects that nonlinear devices such as ac/dc converters, HVDC transmission links, and motor drives have on spacecraft power systems are discussed. The nonsinusoidal currents, along with the corresponding voltages, are calculated by a harmonic power flow which decouples and solves for each harmonic component individually using an iterative Newton-Raphson algorithm. The sparsity of the harmonic equations and the overall Jacobian matrix is used to an advantage in terms of saving computer memory space and in terms of reducing computation time. The algorithm could also be modified to analyze each harmonic separately instead of all at the same time.

  9. Clock Controller For Ac Self-Timing Analysis Of Logic System

    DOEpatents

    Lo, Tinchee; Flanagan, John D.

    2004-05-18

    A clock controller and clock generating method are provided for AC self-test timing analysis of a logic system. The controller includes latch circuitry which receives a DC input signal at a data input, and a pair of continuous out-of-phase clock signals at capture and launch clock inputs thereof. The latch circuitry outputs two overlapping pulses responsive to the DC input signal going high. The two overlapping pulses are provided to waveform shaper circuitry which produces therefrom two non-overlapping pulses at clock speed of the logic system to be tested. The two non-overlapping pulses are a single pair of clock pulses which facilitate AC self-test timing analysis of the logic system.

  10. 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.

  11. Description of a 20 kilohertz power distribution system

    NASA Technical Reports Server (NTRS)

    Hansen, I. G.

    1986-01-01

    A single phase, 440 VRMS, 20 kHz power distribution system with a regulated sinusoidal wave form is discussed. A single phase power system minimizes the wiring, sensing, and control complexities required in a multi-sourced redundantly distributed power system. The single phase addresses only the distribution links multiphase lower frequency inputs and outputs accommodation techniques are described. While the 440 V operating potential was initially selected for aircraft operating below 50,000 ft, this potential also appears suitable for space power systems. This voltage choice recognizes a reasonable upper limit for semiconductor ratings, yet will direct synthesis of 220 V, 3 power. A 20 kHz operating frequency was selected to be above the range of audibility, minimize the weight of reactive components, yet allow the construction of single power stages of 25 to 30 kW. The regulated sinusoidal distribution system has several advantages. With a regulated voltage, most ac/dc conversions involve rather simple transformer rectifier applications. A sinusoidal distribution system, when used in conjunction with zero crossing switching, represents a minimal source of EMI. The present state of 20 kHz power technology includes computer controls of voltage and/or frequency, low inductance cable, current limiting circuit protection, bi-directional power flow, and motor/generator operating using standard induction machines. A status update and description of each of these items and their significance is presented.

  12. Description of a 20 Kilohertz power distribution system

    NASA Technical Reports Server (NTRS)

    Hansen, I. G.

    1986-01-01

    A single phase, 440 VRMS, 20 kHz power distribution system with a regulated sinusoidal wave form is discussed. A single phase power system minimizes the wiring, sensing, and control complexities required in a multi-sourced redundantly distributed power system. The single phase addresses only the distribution link; mulitphase lower frequency inputs and outputs accommodation techniques are described. While the 440 V operating potential was initially selected for aircraft operating below 50,000 ft, this potential also appears suitable for space power systems. This voltage choice recognizes a reasonable upper limit for semiconductor ratings, yet will direct synthesis of 220 V, 3 power. A 20 kHz operating frequency was selected to be above the range of audibility, minimize the weight of reactive components, yet allow the construction of single power stages of 25 to 30 kW. The regulated sinusoidal distribution system has several advantages. With a regulated voltage, most ac/dc conversions involve rather simple transformer rectifier applications. A sinusoidal distribution system, when used in conjunction with zero crossing switching, represents a minimal source of EMI. The present state of 20 kHz power technology includes computer controls of voltage and/or frequency, low inductance cable, current limiting circuit protection, bi-directional power flow, and motor/generator operating using standard induction machines. A status update and description of each of these items and their significance is presented.

  13. Integrated high power VCSEL systems

    NASA Astrophysics Data System (ADS)

    Moench, Holger; Conrads, Ralf; Gronenborn, Stephan; Gu, Xi; Miller, Michael; Pekarski, Pavel; Pollmann-Retsch, Jens; Pruijmboom, Armand; Weichmann, Ulrich

    2016-03-01

    High power VCSEL systems are a novel laser source used for thermal treatment in industrial manufacturing. These systems will be applied in many applications, which have not used a laser source before. This is enabled by the unique combination of efficiency, compactness and robustness. High power VCSEL system technology encompasses elements far beyond the VCSEL chip itself: i.e. heat sinks, bonding technology and integrated optics. This paper discusses the optimization of these components and processes specifically for building high-power laser systems with VCSEL arrays. New approaches help to eliminate components and process steps and make the system more robust and easier to manufacture. New cooler concepts with integrated electrical and mechanical interfaces have been investigated and offer advantages for high power system design. The bonding process of chips on sub-mounts and coolers has been studied extensively and for a variety of solder materials. High quality of the interfaces as well as good reliability under normal operation and thermal cycling have been realized. A viable alternative to soldering is silver sintering. The very positive results which have been achieved with a variety of technologies indicate the robustness of the VCSEL chips and their suitability for high power systems. Beam shaping micro-optics can be integrated on the VCSEL chip in a wafer scale process by replication of lenses in a polymer layer. The performance of VCSEL arrays with integrated collimation lenses has been positively evaluated and the integrated chips are fully compatible with all further assembly steps. The integrated high power systems make the application even easier and more robust. New examples in laser material processing and pumping of solid state lasers are presented.

  14. Power mine door system

    SciTech Connect

    Kennedy, W.R.; Kennedy, J.M.

    1993-06-29

    A mine door system for installation in a passageway in a mine is described, comprising a door frame adapted to be installed in the passageway to define a generally rectangular doorway, said door frame having a top and opposite sides, a mine door comprising a pair of door leaf hinged on opposite sides of the door frame to permit passage through the doorway, each door leaf being generally rectangular in shape with a top horizontal edge, a bottom horizontal edge, a generally vertical hinged side edge adjacent a respective side of the door frame, a generally vertical free side edge opposite the hinged side edge, a first leaf face facing away from the top of the door frame when the door leaf is closed, a second leaf face facing toward the top of the door frame when the door leaf is closed, the door leaf being so dimensioned that there is a substantial vertical gap between the door leaf when they are closed to accommodate convergence of side walls of the passageway, a relatively wide vertical sealing member secured to said first face of one of said door leaf adjacent its free side edge and projecting laterally therefrom for overlapping the first face of the other door leaf adjacent its free side edge thereby to cover said gap between the door leaf when the door leaf are closed, said door leaf having upper corner regions relieved to provide notch-like recesses adjacent the gap on opposite sides of the gap extending from the first leaf faces of the door leaf to the second leaf faces of the door leaf, said sealing member having an inclined upper end portion configured so that, when the door leaf are closed, it slopes upwardly through said recesses and said gap for substantially the full depth of the gap, said inclined upper end portion terminating in a tip engageable with the top of the door frame when the door leaf are closed thereby to inhibit the passage of air through the gap at a location adjacent the top of the door frame.

  15. Dynamic modeling of power systems

    SciTech Connect

    Reed, M.; White, J.

    1995-12-01

    Morgantown Energy Technology Center`s (METC) Process and Project Engineering (P&PE) personnel continue to refine and modify dynamic modeling or simulations for advanced power systems. P&PE, supported by Gilbert/Commonwealth, Inc. (G/C), has adapted PC/TRAX commercial dynamic software to include equipment found in advanced power systems. PC/TRAX`s software contains the equations that describe the operation of standard power plant equipment such as gas turbines, feedwater pumps, and steam turbines. The METC team has incorporated customized dynamic models using Advanced Continuous Simulation Language (ACSL) code for pressurized circulating fluidized-bed combustors, carbonizers, and other components that are found in Advanced Pressurized Fluidized-Bed Combustion (APFBC) systems. A dynamic model of a commercial-size APFBC power plant was constructed in order to determine representative operating characteristics of the plant and to gain some insight into the best type of control system design. The dynamic model contains both process and control model components. This presentation covers development of a model used to describe the commercial APFBC power plant. Results of exercising the model to simulate plant performance are described and illustrated. Information gained during the APFBC study was applied to a dynamic model of a 1-1/2 generation PFBC system. Some initial results from this study are also presented.

  16. Power systems for space exploration

    SciTech Connect

    Shipbaugh, C.; Solomon, K.A.

    1992-01-01

    The Outreach Program was designed to solicit creative ideas from academia, research institutions, private enterprises, and the general public and is intended to be helpful in defining promising technical areas and program paths for more detailed study. To the Outreach Program, a number of power system concepts were proposed. In conclusion, there are a number of advanced concepts for space power and propulsion sources that deserve study if we want to expand our ability to not only explore space, but to utilize it. Advanced nuclear concepts and power beaming concepts are two areas worthy of detailed assessments.

  17. Power systems for space exploration

    NASA Astrophysics Data System (ADS)

    Shipbaugh, Calvin; Solomon, Kenneth A.

    The Outreach Program was designed to solicit creative ideas from academia, research institutions, private enterprises, and the general public and is intended to be helpful in defining promising technical areas and program paths for more detailed study. To the Outreach Program, a number of power system concepts were proposed. In conclusion, there are a number of advanced concepts for space power and propulsion sources that deserve study if we want to expand our ability to not only explore space, but to utilize it. Advanced nuclear concepts and power beaming concepts are two areas worthy of detailed assessments.

  18. Reliable compact electrical power source systems for space launch vehicles

    SciTech Connect

    Young, A.R.

    1996-12-31

    Described herein are several key technologies utilized in the design of a family of direct-drive turboalternator systems for space launch vehicles. These systems automatically provide conditioned and regulated electrical power at various voltages, powering actuators, valves, and avionics throughout the vehicle. The simple and robust ring-wound two-pole toothless alternator operates at peripheral speeds, making it suitable to be driven directly by a turbine, thereby eliminating the weight, reliability, zero ``g`` lubrication, and cooling issues of a speed-reducing gearbox, while allowing the turbine to operate at reasonable efficiency. Additionally, the use of self-aligning foil bearing and catalytic combustors or cold gas propellants enhance the reliability. The power conditioner and electronic controller provide hands-off regulated ac or dc power on demand, maintaining critical parameters within established limits and performance while reporting on built-in health-monitoring tests.

  19. Hybrid power management system and method

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J. (Inventor)

    2007-01-01

    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.

  20. 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.

  1. Ignitor Electrical Power Supply System

    NASA Astrophysics Data System (ADS)

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

    2004-11-01

    An iterative optimization process to reduce the total installed electrical power required for Ignitor has been performed, bringing its value down to about 70% of that estimated originally. Ignitor is planned to be installed within the 400 kV Station of Rondissone (near Turin). The required electrical power (1000 MVA / 320 MVAr, including 480 MVAr locally compensated through static system, SVC) has been demonstrated by the technical authority GRTN to be compatible with the Grid capability. The magnet systems of Ignitor are supplied by means of a set of 14, 12 pulse, current regulated, sequentially or internal freewheeling controlled, fully static power amplifier units which are installed inside standard, outdoor-kind containers, located near to the related step-down transformers. Each container can house up to 100 MW, 2x12 pulse power amplifier units. The connection between the power amplifiers and the machine is performed by means of coaxial, outdoor-kind, segregated bus-bars. These choices make the whole power supply system as flexible as possible in terms of the overall layout of the Ignitor plant.

  2. Solar power satellite microwave power transmission system description executive summary

    NASA Astrophysics Data System (ADS)

    Woodcock, G. R.

    1980-12-01

    The history of the concept of microwave power beaming to Earth is reviewed with emphasis on transmission frequency selection. Constraints on the system power level results from (1) required rejection of waste heat resulting from inefficiencies in the cover conversion of dc electric power to microwave power; (2) the rf power intensity in the ionosphere; and (3) the effect of sidelobe level on aperture illumination factors. Transmitter arrangement, the power distribution system, attitude control, subarrays, waveguides, and alignment are discussed.

  3. Protecting a HVDC link against accidental isolation from its receiving AC system

    SciTech Connect

    Whitehouse, R.S. )

    1993-07-01

    When an HVdc scheme is isolated from its receiving ac system, the inverter may continue to operate, generating its own ac bus voltages; this is defined here as islanding. If islanding is allowed to continue unrestricted, then main circuit components may in some conditions be damaged and it is therefore necessary to provide a suitable protection system. This paper outlines the protection scheme developed for the McNeill Back-to-Back HVdc link in Alberta, Canada, to prevent damage due to islanding while still permitting the link to automatically restart on reclosure of the isolating breaker. Oscillograms showing the protection in operation on both the GEC ALSTHOM HVdc simulator and during tests carried out as part of the commissioning of the McNeill HV dc link are included.

  4. Utility-Scale Power Router: Dynamic Control of Grid Assets Using Direct AC Converter Cells

    SciTech Connect

    2010-09-01

    ADEPT Project: Georgia Tech is developing a cost-effective, utility-scale power router that uses an enhanced transformer to more efficiently direct power on the grid. Existing power routing technologies are too expensive for widespread use, but the ability to route grid power to match real-time demand and power outages would significantly reduce energy costs for utilities, municipalities, and consumers. Georgia Tech is adding a power converter to an existing grid transformer to better control power flows at about 1/10th the cost of existing power routing solutions. Transformers convert the high-voltage electricity that is transmitted through the grid into the low-voltage electricity that is used by homes and businesses. The added converter uses fewer steps to convert some types of power and eliminates unnecessary power storage, among other improvements. The enhanced transformer is more efficient, and it would still work even if the converter fails, ensuring grid reliability.

  5. Study on AC-DC Electrical Conductivities in Warm Dense Matter Generated by Pulsed-power Discharge with Isochoric Vessel

    NASA Astrophysics Data System (ADS)

    Sasaki, Toru; Ohuchi, Takumi; Takahashi, Takuya; Kawaguchi, Yoshinari; Saito, Hirotaka; Miki, Yasutoshi; Takahashi, Kazumasa; Kikuchi, Takashi; Aso, Tsukasa; Harada, Nob.

    2016-03-01

    To observe AC and DC electrical conductivity in warm dense matter (WDM), we have demonstrated to apply the spectroscopic ellipsometry for a pulsed-power discharge with isochoric vessel. At 10 μs from the beginning of discharge, the generated parameters by using pulsed-power discharge with isochoric vessel are 0.1 ρ s (ρ s: solid density) of density and 4000 K of temperature, respectively. The DC electrical conductivity for above parameters is estimated to be 104 S/m. In order to measure the AC electrical conductivity, we have developed a four-detector spectroscopic ellipsometer with a multichannel spectrometer. The multichannel spectrometer, in which consists of a 16-channel photodiode array, a two-stages voltage adder, and a flat diffraction grating, has 10 MHz of the frequency response with covered visible spectrum. For applying the four-detector spectroscopic ellipsometer, we observe the each observation signal evolves the polarized behavior compared to the ratio as I 1/I 2.

  6. Pegasus power system facility upgrades

    NASA Astrophysics Data System (ADS)

    Lewicki, B. T.; Kujak-Ford, B. A.; Winz, G. R.

    2008-11-01

    Two key Pegasus systems have been recently upgraded: the Ohmic-transformer IGCT bridge control system, and the plasma-gun injector power system. The Ohmic control system contains two new microprocessor controlled components to provide an interface between the PWM controller and the IGCT bridges. An interface board conditions the command signals from the PWM controller. A splitter/combiner board routes the conditioned PWM commands to an array of IGCT bridges and interprets IGCT bridge status. This system allows for any PWM controller to safely control IGCT bridges. Future developments will include a transition to a polyphasic bridge control. This will allow for 3 to 4 times the present pulse length and provide a much higher switching frequency. The plasma gun injector system now includes active current feedback control on gun bias current via PWM buck type power supplies. Near term goals include a doubling or tripling of the applied bias voltage. Future arc bias system power supplies may include a simpler boost type system which will allow access to even higher voltages using existing low voltage energy storage systems.

  7. Nanosat Intelligent Power System Development

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  8. ADVANCED POWER SYSTEMS ASH BEHAVIOR IN POWER SYSTEMS

    SciTech Connect

    ZYGARLICKE, CHRISTOPHER J; MCCOLLOR, DONALD P; KAY, JOHN P; SWANSON, MICHAEL L

    1998-09-01

    The overall goal of this initiative is to develop fundamental knowledge of ash behavior in power systems for the purpose of increasing power production efficiency, reducing operation and maintenance costs, and reducing greenhouse gas emissions into the atmosphere. The specific objectives of this initiative focus primarily on ash behavior related to advanced power systems and include the following: Determine the current status of the fundamental ash interactions and deposition formation mechanisms as already reported through previous or ongoing projects at the EERC or in the literature. Determine sintering mechanisms for temperatures and particle compositions that are less well known and remain for the most part undetermined. Identify the relationship between the temperature of critical viscosity (Tcv ) as measured in a viscometer and the crystallization occurring in the melt. Perform a literature search on the use of heated-stage microscopy (HSM) for examining in situ ash-sintering phenomena and then validate the use of HSM in the determination of viscosity in spherical ash particles. Ascertain the formation and stability of specific mineral or amorphous phases in deposits typical of advanced power systems. Evaluate corrosion for alloys being used in supercritical combustion systems.

  9. Power System Concepts for the Lunar Outpost: A Review of the Power Generation, Energy Storage, Power Management and Distribution (PMAD) System Requirements and Potential Technologies for Development of the Lunar Outpost

    NASA Technical Reports Server (NTRS)

    Khan, Z.; Vranis, A.; Zavoico, A.; Freid, S.; Manners, B.

    2006-01-01

    This paper will review potential power system concepts for the development of the lunar outpost including power generation, energy storage, and power management and distribution (PMAD). In particular, the requirements of the initial robotic missions will be discussed and the technologies considered will include cryogenics and regenerative fuel cells (RFC), AC and DC transmission line technology, high voltage and low voltage power transmission, conductor materials of construction and power beaming concepts for transmitting power to difficult to access locations such as at the bottom of craters. Operating conditions, component characteristics, reliability, maintainability, constructability, system safety, technology gaps/risk and adaptability for future lunar missions will be discussed for the technologies considered.

  10. A novel ZePoC encoder for sinusoidal signals with a predictable accuracy for an AC power standard

    NASA Astrophysics Data System (ADS)

    Vennemann, T.; Frye, T.; Liu, Z.; Kahmann, M.; Mathis, W.

    2015-11-01

    In this paper we present an analytical formulation of a Zero Position Coding (ZePoC) encoder for an AC power standard based on class-D topologies. For controlling a class-D power stage a binary signal with special spectral characteristics will be generated by this ZePoC encoder for sinusoidal signals. These spectral characteristics have a predictable accuracy within a separated baseband to keep the noise floor below a specified level. Simulation results will validate the accuracy of this novel ZePoC encoder. For a real-time implementation of the encoder on a DSP/FPGA hardware architecture a trade-off between accuracy and speed of the ZePoC algorithm has to be made. Therefore the numerical effects of different floating point formats will be analyzed.

  11. 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.

  12. NASA's Radioisotope Power Systems - Plans

    NASA Technical Reports Server (NTRS)

    Hamley, John A.; Mccallum, Peter W.; Sandifer, Carl E., II; Sutliff, Thomas J.; Zakrajsek, June F.

    2015-01-01

    NASA's Radioisotope Power Systems (RPS) Program continues to plan and implement content to enable planetary exploration where such systems could be needed, and to prepare more advanced RPS technology for possible infusion into future power systems. The 2014-2015 period saw significant changes, and strong progress. Achievements of near-term objectives have enabled definition of a clear path forward in which payoffs from research investments and other sustaining efforts can be applied. The future implementation path is expected to yield a higher-performing thermoelectric generator design, a more isotope-fuel efficient system concept design, and a robust RPS infrastructure maintained effectively within both NASA and the Department of Energy. This paper describes recent work with an eye towards the future plans that result from these achievements.

  13. Power-cable-carrier control (PC/sup 3/) system

    SciTech Connect

    Alvis, R.L.; Wally, K.; Rosborough, J.R.

    1981-04-01

    A control system has been developed that uses a carrier signal imposed on an existing ac power circuit to transmit commands. This system was specifically developed to control an entire solar collector field by sending sun-tracking information to the trough collectors or by commanding them to assume safe positions (STOW) if out-of-limit conditions were encountered. Objectives were to develop a control system that operates reliably and has enough functions to control an entire collector field, yet do it at less cost than for conventional approaches. Development, design, operating characteristics, and field testing and results of the new system, the Power Cable Carrier Control (PC/sup 3/) System are described.

  14. Development and test of the ASAT Bipropellant Attitude Control System (ACS) engine

    NASA Astrophysics Data System (ADS)

    Hodge, K. F.; Allen, K. A.; Hemmings, B.

    1993-06-01

    The recent Kinetic Energy Anti-Satellite (KE ASAT) Bipropellant Attitude Control System (ACS) Engine testing demonstrated and characterized performance and operational durability. Within the ASAT mission, the bipropellant engines are used to despin the missile after shroud deployment and to provide attitude control of the Kill Vehicle (KV) during all phases of the KV free flight. These engines provide all attitude control thrust from booster separation until target intercept. The ASAT ACS engine is unique both in the amount of on-time that the engine sees during a tactical mission scenario and the high thermal loads which result from performing two diametrically opposed missions with a single thruster - long steady state burns and very short response time pulse mode operations. Two flightweight ASAT ACS Bipropellant engines were individually tested in a developmental test program. Testing was conducted at ambient conditions. Hot-fire testing consisted of steady-state, mission duty cycle (MDC), Chamber Pressure (Pc) excursion, mixture ratio excursion, and pulse performance. Testing was conducted by Rockwell's Rocketdyne Division at the Santa Susana Field Laboratory (SSFL), Systems Test Laboratory IV (STL IV), Cell 37A. Two additional engine tests are planned and will include altitude testing. This paper will summarize engine development, component development testing, valve orificing and cold flow calibration, and engine hot-fire testing approach and results.

  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. Design and emplacement of an integrated lunar power system - Issues and concerns

    NASA Technical Reports Server (NTRS)

    Sprouse, Kenneth M.; Robin, James E.; Metcalf, Kenneth J.; Cataldo, Robert

    1991-01-01

    Issues regarding the construction and operation of a stationary lunar surface power system that must be resolved in order to create a permanent manned presence on the moon are addressed. The issues considered include: (1) the centralization or decentralization of the electrical power system; (2) whether power transmission should be ac or dc; (3) what mix of power generating technology should be used; and (4) the physical interface requirements between the power-system hardware and the construction equipment to be used in placing the hardware on the lunar surface.

  17. Bonneville, Power Administration Timing System

    NASA Technical Reports Server (NTRS)

    Martin, Kenneth E.

    1996-01-01

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

  18. Manned spacecraft electrical power systems

    NASA Technical Reports Server (NTRS)

    Simon, William E.; Nored, Donald L.

    1987-01-01

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

  19. Beamlet pulsed-power system

    SciTech Connect

    Larson, D.

    1996-06-01

    The 13-MJ Beamlet pulsed-power system provides power to the 512 flash lamps in the cavity and booster amplifiers. Since the flash lamps pump all of the apertures in the 2 x 2 amplifier array, the capacitor bank provides roughly four times the energy required to pump the single active beam line. During the 40 s prior to the shot, the capacitors are charged by constant-current power supplies. Ignitron switches transfer the capacitor energy to the flash lamps via coaxial cables. A preionization system triggers the flash lamps and delivers roughly 1 % of the capacitor energy 200 {mu}s prior to the main discharge. This is the first time flash-lamp preionization has been used in a large facility. Preionization improves the amplifier efficiency by roughly 5% and increases the lifetime of the flash lamps. LabVIEW control panels provide an operator interface with the modular controls and diagnostics. To improve the reliability of the system, high-energy-density, self-healing, metallized dielectric capacitors are used. High-frequency, voltage-regulated switching power supplies are integrated into each module on Beamlet, allowing greater independence among the modules and improved charge voltage accuracy, flexibility, and repeatability.

  20. Transport ac loss in a rectangular thin strip with power-law E (J) relation

    NASA Astrophysics Data System (ADS)

    Li, Shuo; Chen, Du-Xing; Fan, Yu; Fang, Jin

    2015-01-01

    Transport ac losses of a rectangular thin strip obeying relation E /Ec =(J /Jc) n with a fixed critical current Ic and n = 5, 10, 20, 30 , and 40 are accurately computed at a fixed frequency f as functions of the current amplitude Im . The results may be interpolated and scaled to those at any values of Ic, f , and 5 ⩽ n ⩽ 40 . Normalized in the same way as that in Norris' analytical formula derived from the critical-state model and converting f to a critical frequency fc , the modeling results may be better compared with the Norris formula and experimental data. A complete set of calculated modeling data are given with necessary formulas to be easily used by experimentalists in any particular case.

  1. Development of a hardware-based AC microgrid for AC stability assessment

    NASA Astrophysics Data System (ADS)

    Swanson, Robert R.

    As more power electronic-based devices enable the development of high-bandwidth AC microgrids, the topic of microgrid power distribution stability has become of increased interest. Recently, researchers have proposed a relatively straightforward method to assess the stability of AC systems based upon the time-constants of sources, the net bus capacitance, and the rate limits of sources. In this research, a focus has been to develop a hardware test system to evaluate AC system stability. As a first step, a time domain model of a two converter microgrid was established in which a three phase inverter acts as a power source and an active rectifier serves as an adjustable constant power AC load. The constant power load can be utilized to create rapid power flow transients to the generating system. As a second step, the inverter and active rectifier were designed using a Smart Power Module IGBT for switching and an embedded microcontroller as a processor for algorithm implementation. The inverter and active rectifier were designed to operate simultaneously using a synchronization signal to ensure each respective local controller operates in a common reference frame. Finally, the physical system was created and initial testing performed to validate the hardware functionality as a variable amplitude and variable frequency AC system.

  2. Adiabatic response and quantum thermoelectrics for ac-driven quantum systems

    NASA Astrophysics Data System (ADS)

    Ludovico, María Florencia; Battista, Francesca; von Oppen, Felix; Arrachea, Liliana

    2016-02-01

    We generalize the theory of thermoelectrics to include coherent electron systems under adiabatic ac driving, accounting for quantum pumping of charge and heat, as well as for the work exchanged between the electron system and driving potentials. We derive the relevant response coefficients in the adiabatic regime and show that they obey generalized Onsager reciprocity relations. We analyze the consequences of our generalized thermoelectric framework for quantum motors, generators, heat engines, and heat pumps, characterizing them in terms of efficiencies and figures of merit. We illustrate these concepts in a model for a quantum pump.

  3. Spin superconductivity and ac-Josephson effect in Graphene system under strong magnetic field

    NASA Astrophysics Data System (ADS)

    Liu, Haiwen; Jiang, Hua; Sun, Qing-Feng; Xie, X. C.; Collaborative Innovation Center of Quantum Matter, Beijing, China Collaboration

    We study the spin superconductivity in Graphene system under strong magnetic field. From the microscopically Gor'kov method combined with the Aharonov-Casher effect, we derive the effective Landau-Ginzburg free energy and analyze the time evolution of order parameter, which is confirmed to be the off-diagonal long range order. Meanwhile, we compare the ground state of spin superconductivity to the canted-antiferromagnetic state, and demonstrate the equivalence between these two states. Moreover, we give out the pseudo-field flux quantization condition of spin supercurrent, and propose an experimental measurable ac-Josephson effect of spin superconductivity in this system.

  4. Comparison of the Accuracy and Speed of Transient Mobile A/C System Simulation Models: Preprint

    SciTech Connect

    Kiss, T.; Lustbader, J.

    2014-03-01

    The operation of air conditioning (A/C) systems is a significant contributor to the total amount of fuel used by light- and heavy-duty vehicles. Therefore, continued improvement of the efficiency of these mobile A/C systems is important. Numerical simulation has been used to reduce the system development time and to improve the electronic controls, but numerical models that include highly detailed physics run slower than desired for carrying out vehicle-focused drive cycle-based system optimization. Therefore, faster models are needed even if some accuracy is sacrificed. In this study, a validated model with highly detailed physics, the 'Fully-Detailed' model, and two models with different levels of simplification, the 'Quasi-Transient' and the 'Mapped- Component' models, are compared. The Quasi-Transient model applies some simplifications compared to the Fully-Detailed model to allow faster model execution speeds. The Mapped-Component model is similar to the Quasi-Transient model except instead of detailed flow and heat transfer calculations in the heat exchangers, it uses lookup tables created with the Quasi-Transient model. All three models are set up to represent the same physical A/C system and the same electronic controls. Speed and results of the three model versions are compared for steady state and transient operation. Steady state simulated data are also compared to measured data. The results show that the Quasi-Transient and Mapped-Component models ran much faster than the Fully-Detailed model, on the order of 10- and 100-fold, respectively. They also adequately approach the results of the Fully-Detailed model for steady-state operation, and for drive cycle-based efficiency predictions

  5. Using SMES as a multi-purpose interface in power generation, transmission and distribution systems

    NASA Astrophysics Data System (ADS)

    Tam, Kwa-Sur; Zhang, X.; Yarali, A.

    The objectives are to introduce the concept of the multiterminal superconductive magnetic energy storage (MSMES) scheme and to show that new SMES applications and more SMES benefits to electric power systems can be realized by using MSMES. The authors show a schematic diagram of the conventional SMES system. The SMES magnet is charged and discharged through one dc/ac converter terminal and the SMES unit is connected as a shunt device to the ac power system. The authors show a schematic diagram of a three-terminal SMES system which is used to explain the principle of operation of a MSMES system. Potential applications of MSMES systems in power generation, transmission, and distribution systems are discussed.

  6. 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.

  7. Method and system for an on-chip AC self-test controller

    DOEpatents

    Flanagan, John D.; Herring, Jay R.; Lo, Tin-Chee

    2008-09-30

    A method and system for performing AC self-test on an integrated circuit that includes a system clock for use during normal operation are provided. The method includes applying a long data capture pulse to a first test register in response to the system clock, applying an at speed data launch pulse to the first test register in response to the system clock, inputting the data from the first register to a logic path in response to applying the at speed data launch pulse to the first test register, applying an at speed data capture pulse to a second test register in response to the system clock, inputting the logic path output to the second test register in response to applying the at speed data capture pulse to the second test register, and applying a long data launch pulse to the second test register in response to the system clock.

  8. Low-power wireless on-chip microparticle manipulation system

    NASA Astrophysics Data System (ADS)

    Dei, Yoshiaki; Kishiwada, Yasushi; Yamane, Rie; Inoue, Taisuke; Matsuoka, Toshimasa

    2015-04-01

    In order to realize an easy-to-use on-chip microparticle manipulation system, a chip that can manipulate microparticles by pulse-driven dielectrophoresis (DEP) in a solution with wireless power reception function was designed. Considering both of the DEP operation and power consumption of the chip, the internal supply voltage and the DEP driving signal frequency for CMOS digital circuits including the ring oscillator were assigned to about 0.5 V and about 1 MHz, respectively. The simulation results of wireless power transfer reveals that the use of higher-frequency (13 MHz) and input-matching circuits improve power transfer efficiency (4.7% for the rectification and DEP driving signal generation) and a smaller required available power of the AC power source (19.2 mW). The chip fabricated in a 180 nm triple-well CMOS process demonstrates the wireless on-chip DEP operation. Compared with power transfer systems using an off-chip transformer, the small primary coil on the PCB and the on-chip secondary coil dominate the power dissipation.

  9. Wireless transmission of power and information through one high-frequency resonant AC link inverter for robot manipulator applications

    SciTech Connect

    Kawamura, Atsuo; Ishioka, K.; Hirai, J.

    1996-05-01

    A contactless decentralized power supply is proposed with communication capability through only one transformer. A prototype of wireless transmission system of power and information (WTPI system) was built, and the two-axis position controls of servo motors were achieved by transferring the power and signal through one rotatable high-frequency transformer. The proposed concept can be applied for robotics and numerical control (NC) machines.

  10. 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).

  11. Electrical power systems for Space Station

    NASA Technical Reports Server (NTRS)

    Simon, W. E.

    1984-01-01

    Major challenges in power system development are described. Evolutionary growth, operational lifetime, and other design requirements are discussed. A pictorial view of weight-optimized power system applications shows which systems are best for missions of various lengths and required power level. Following definition of the major elements of the electrical power system, an overview of element options and a brief technology assessment are presented. Selected trade-study results show end-to-end system efficiencies, required photovoltaic power capability as a function of energy storage system efficiency, and comparisons with other systems such as a solar dynamic power system.

  12. A 65-kV insulated gate bipolar transistor switch applied in damped AC voltages partial discharge detection system.

    PubMed

    Jiang, J; Ma, G M; Luo, D P; Li, C R; Li, Q M; Wang, W

    2014-02-01

    Damped AC voltages detection system (DAC) is a productive way to detect the faults in power cables. To solve the problems of large volume, complicated structure and electromagnetic interference in existing switches, this paper developed a compact solid state switch based on electromagnetic trigger, which is suitable for DAC test system. Synchronous electromagnetic trigger of 32 Insulated Gate Bipolar Transistors (IGBTs) in series was realized by the topological structure of single line based on pulse width modulation control technology. In this way, external extension was easily achieved. Electromagnetic trigger and resistor-capacitor-diode snubber circuit were optimized to reduce the switch turn-on time and circular layout. Epoxy encapsulating was chosen to enhance the level of partial discharge initial voltage (PDIV). The combination of synchronous trigger and power supply is proposed to reduce the switch volume. Moreover, we have overcome the drawback of the electromagnetic interference and improved the detection sensitivity of DAC by using capacitor storage energy to maintain IGBT gate driving voltage. The experimental results demonstrated that the solid-state switch, with compact size, whose turn-on time was less than 400 ns and PDIV was more than 65 kV, was able to meet the actual demands of 35 kV DAC test system. PMID:24593382

  13. A 65-kV insulated gate bipolar transistor switch applied in damped AC voltages partial discharge detection system

    NASA Astrophysics Data System (ADS)

    Jiang, J.; Ma, G. M.; Luo, D. P.; Li, C. R.; Li, Q. M.; Wang, W.

    2014-02-01

    Damped AC voltages detection system (DAC) is a productive way to detect the faults in power cables. To solve the problems of large volume, complicated structure and electromagnetic interference in existing switches, this paper developed a compact solid state switch based on electromagnetic trigger, which is suitable for DAC test system. Synchronous electromagnetic trigger of 32 Insulated Gate Bipolar Transistors (IGBTs) in series was realized by the topological structure of single line based on pulse width modulation control technology. In this way, external extension was easily achieved. Electromagnetic trigger and resistor-capacitor-diode snubber circuit were optimized to reduce the switch turn-on time and circular layout. Epoxy encapsulating was chosen to enhance the level of partial discharge initial voltage (PDIV). The combination of synchronous trigger and power supply is proposed to reduce the switch volume. Moreover, we have overcome the drawback of the electromagnetic interference and improved the detection sensitivity of DAC by using capacitor storage energy to maintain IGBT gate driving voltage. The experimental results demonstrated that the solid-state switch, with compact size, whose turn-on time was less than 400 ns and PDIV was more than 65 kV, was able to meet the actual demands of 35 kV DAC test system.

  14. Power Systems for the RHIC First Sextant Test

    NASA Astrophysics Data System (ADS)

    Lambiase, R. F.; Bruno, D.; Feng, P. K.; Haque, T.; Schultheiss, C.

    1997-05-01

    The first sextant test of the RHIC project is an opportunity to evaluate the many systems that must work together for the accelerator to operate. For the main dipole string, the actual main quadrupole power supply with its DSP regulator and output circuit compartments will be used. Temporary supplies will be used for the main quadrupole string, quadrupole offset, and quadrupole shunt supplies. This will let us both measure the performance of the main supply as well as determine the interaction among other power elements in the circuit. Correction elements will also be powered. The actual gamma-T power supplies will be used, as well as temporary supplies for the dipole correctors and sextupole supplies. Some of these units are required for beam to be transported, others are to be operated without beam to measure their performance, and how they interact with their superconducting loads. The power supply equipment, and that of other systems, required an infrastucture of AC power and output cable distribution in the RHIC tunnel, outlying service buildings, and interconnecting the tunnel to the service buildings. This note will describe the performance of the RHIC power supply systems during the sextant test, and the experience gained from this exercise.

  15. Power systems for the RHIC first sextant test

    SciTech Connect

    Schultheiss, C.; Bruno, D.; Feng, P.K.

    1997-07-01

    The first sextant test of the RHIC project is an opportunity to evaluate the many systems that must work together for the accelerator to operate. For the main dipole string, the actual main quadrupole power supply with its DSP regulator and output circuit compartment will be used. Temporary supplies will be used for the main quadrupole string, quadrupole offset, and quadrupole shunt supplies. This will let the authors both measure the performance of the main supply as well as determine the interaction among other power elements in the circuit. Correction elements will also be powered. The actual gamma-T power supplies will be used, as well as temporary supplies for the dipole correctors and sextupole supplies. Some of these units are required for beam to be transported, others are to be operated without beam to measure their performance, and how they interact with their superconducting loads. The power supply equipment, and that of other systems, required an infrastucture of AC power and output cable distribution in the RHIC tunnel, outlying service buildings, and interconnecting the tunnel to the service buildings. This note will describe the performance of the RHIC power supply systems during the sextant test, and the experience gained from this exercise.

  16. Functional validation of cadherin as a receptor of Bt toxin Cry1Ac in Helicoverpa armigera utilizing the CRISPR/Cas9 system.

    PubMed

    Wang, Jing; Zhang, Haonan; Wang, Huidong; Zhao, Shan; Zuo, Yayun; Yang, Yihua; Wu, Yidong

    2016-09-01

    Cadherins have been identified as receptors of Bacillus thuringiensis (Bt) Cry1A toxins in several lepidopteran insects including the cotton bollworm, Helicoverpa armigera. Disruption of the cadherin gene HaCad has been genetically linked to resistance to Bt toxin Cry1Ac in H. armigera. By using the CRISPR/Cas9 genome editing system (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9), HaCad from the Cry1Ac-susceptible SCD strain of H. armigera was successfully knocked out. A single positive CRISPR event with a frame shift deletion of 4 nucleotides was identified and made homozygous to create a knockout line named SCD-Cad. Western blotting confirmed that HaCad was no longer expressed in the SCD-Cad line while an intact HaCad of 210 kDa was present in the parental SCD strain. Insecticide bioassays were used to show that SCD-Cad exhibited 549-fold resistance to Cry1Ac compared with SCD, but no significant change in susceptibility to Cry2Ab. Our results not only provide strong reverse genetics evidence for HaCad as a functional receptor of Cry1Ac, but also demonstrate that the CRISPR/Cas9 technique can act as a powerful and efficient genome editing tool to study gene function in a global agricultural pest, H. armigera. PMID:27343383

  17. Investigation of potential driver modules and transmission lines for a high frequency power system on the space station

    NASA Technical Reports Server (NTRS)

    Brush, Harold T.

    1986-01-01

    The feasibility of using Series Resonant Inverter as the driver module for high frequency power system on the Space Station was assessed. The performance of the Series Resonant Inverter that was used in the testing of the single-phase, 2.0-kw resonant AC power system breadboard is summarized. The architecture is descirbed and the driver modules of the 5.0 kw AC power system breadboard are analyzed. An investigation of the various types of transmission lines is continued. Measurements of equivalent series resistor and inductor and equivalent parallel capacitors are presented. In particular, a simplified approach is utilized to describe the optimal transmission line.

  18. Phase synchronized quasiperiodicity in power electronic inverter systems

    NASA Astrophysics Data System (ADS)

    Zhusubaliyev, Zhanybai T.; Mosekilde, Erik; Andriyanov, Alexey I.; Shein, Vladimir V.

    2014-02-01

    The development of switch-mode operated power electronic converter systems has provided a broad range of new effective approaches to the conversion of electric power. In this paper we describe the transitions from regular periodic operation to quasiperiodicity and high-periodic resonance behavior that can be observed in a pulse-width modulated DC/AC converter operating with high feedback gain. We demonstrate the occurrence of two different types of torus birth bifurcations and present a series of phase portraits illustrating the appearance of phase-synchronized quasiperiodicity. Our numerical findings are verified through comparison with an experimental inverter system. The results shed light on the transitions to quasiperiodicity and to various forms of three-frequency dynamics in non-smooth systems.

  19. 1982 engineering conference on reliability for the electrical power industry

    SciTech Connect

    Campbell, D.J.; Arendt, J.S.; Battle, R.E.; Baranowsky, P.W.

    1982-01-01

    Emergency onsite ac power systems at nuclear power plants are a major concern in plant risk assessments because of the relatively large frequency of loss of offsite power and the dependence of most other safety systems on ac power. Detailed reviews of onsite ac power system designs and reviews of experience with diesel generators at US nuclear power plants form the basis of system reliability analyses that show significant improvements in reliability can be obtained at moderate cost for some plants. Onsite ac power system modifications analyzed include procedural modifications, minor equipment modifications and major equipment additions. Relative costs of various modifications are compared with associated system reliability improvements.

  20. Method and system for an on-chip AC self-test controller

    DOEpatents

    Flanagan, John D.; Herring, Jay R.; Lo, Tin-Chee

    2006-06-06

    A method for performing AC self-test on an integrated circuit, including a system clock for use during normal operation. The method includes applying a long data capture pulse to a first test register in response to the system clock, and further applying at an speed data launch pulse to the first test register in response to the system clock. Inputting the data from the first register to a logic path in response to applying the at speed data launch pulse to the first test register. Applying at speed data capture pulse to a second test register in response to the system clock. Inputting the output from the logic path to the second test register in response to applying the at speed data capture pulse to the second register. Applying a long data launch pulse to the second test register in response to the system clock.

  1. Efficient harvesting of wet blue-green microalgal biomass by two-aminoclay [AC]-mixture systems.

    PubMed

    Ji, Hye-Min; Lee, Hyun Uk; Kim, Eui Jin; Seo, Soonjoo; Kim, Bohwa; Lee, Go-Woon; Oh, You-Kwan; Kim, Jun Yeong; Huh, Yun Suk; Song, Hyun A; Lee, Young-Chul

    2016-07-01

    Blue-green microalgal blooms have been caused concerns about environmental problems and human-health dangers. For removal of such cyanobacteria, many mechanical and chemical treatments have been trialled. Among various technologies, the flocculation-based harvesting (precipitation) method can be an alternative if the problem of the low yield of recovered biomass at low concentrations of cyanobacteria is solved. In the present study, it was utilized mixtures of magnesium aminoclay [MgAC] and cerium aminoclay [CeAC] with different particle sizes to harvest cyanobacteria feedstocks with ∼100% efficiency within 1h by ten-fold lower loading of ACs compared with single treatments of [MgAC] or [CeAC]. This success was owed to the compact networks of the different-sized-ACs mixture for efficient bridging between microalgal cells. In order to determine the usage potential of biomass harvested with AC, the mass was heat treated under the reduction condition. This system is expected to be profitably utilizable in adsorbents and catalysts. PMID:27023387

  2. Communications and control for electric power systems: Final report

    SciTech Connect

    Kirkham, H.

    1998-04-01

    This report is a summary of some of the work done on the Communications and Control project, with particular emphasis on the achievements during the years 1986--1996. During those years, the project moved away from concern with dispersed storage and generation and its impact on power system operation (the team was responsible for studies in this area, and for making a power system simulator that included DSG), and became involved in more concrete work aimed at applying high-tech solutions to problems of power system communications and control. This report covers work done at JPL on the following topics: (1) the measurement of electric and magnetic fields, both ac and dc; (2) the use of optical power to supply low-power electronics; (3) the design of a fault-tolerant communication system designed for distribution automation; and (4) a digital phase locked loop that allows the use of low-power transmitting electronics to recreate a good-quality signal at the receiver. In a report of this kind, only the results and highlights of the work are described.

  3. 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.

  4. High-voltage (270 V) dc power-generating system for fighter aircraft

    NASA Technical Reports Server (NTRS)

    Mcginley, K. M.

    1983-01-01

    The advantages of using high voltage, direct current advanced power generating systems in fighter aircraft are discussed. Weight reduction is achieved. Efficiency is increased 85 to 90 percent by eliminating the constant speed drive. Power interruptions are eliminated. There are no speed restrictions and no powerline constraints. Personal safety is increased by eliminating the hold on frequency, present in ac systems, which causes muscle contractions.

  5. Study on photovoltaic power system on ships

    SciTech Connect

    Katagi, Takeshi; Fujii, Yoshimi; Nishikawa, Eiichi; Hashimoto, Takeshi

    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.

  6. Advanced secondary power system for transport aircraft

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  7. Investigation of the stability of AC repulsive force levitation systems for low-speed maglev.

    SciTech Connect

    He, J. L.; Wang, Z.; Rote, D. M.; Winkelman, S.; Energy Systems

    1992-09-01

    Discusses the stability of an AC induction levitation system, focusing on the analysis and optimum design of the secondary conductor. Several improved secondary conductor geometries are considered. A theoretical model with numerical results, as well as experimental observations and data are presented. Theoretical and experimental results indicate that only marginal stability can be achieved with a single-plate secondary conductor. Modifications of the single plate can enhance its stability at rest, but this design suffers from longitudinal instabilities when propelled. It is concluded that a double-plate secondary conductor is stable in all six degrees of freedom.

  8. Orthogonal-core type three-phase dc-ac converter

    SciTech Connect

    Ichinokura, O.; Saito, H.; Jinzenji, T. ); Tajima, K. )

    1993-03-01

    In a previous paper, the authors proposed an orthogonal-core type dc-ac converter for use in photovoltaic power systems. The dc-ac converter has such desirable features as a simple construction, high degree of safety, and ease of maintenance. The operating characteristics of a single-phase converter for residential photovoltaic power systems have also been reported. In this paper, the authors discuss the basic operation of an orthogonal-core type dc-ac converter for a three-phase power system based on simulations and experiments. An optimal construction of the orthogonal-core type three-phase dc-ac converter has been developed.

  9. Assessment of flywheel energy storage for spacecraft power systems

    SciTech Connect

    Rodriguez, G.E.; Studer, P.A.; Baer, D.A.

    1983-05-01

    The feasibility of inertial energy storage in a spacecraft power system is evaluated on the basis of a conceptual integrated design that encompasses a composite rotor, magnetic suspension, and a permanent magnet (PM) motor/generator for a 3-kW orbital average payload at a bus distribution voltage of 250 volts dc. The conceptual design, which evolved at the Goddard Space Flight Center (GSFC), is referred to as a Mechanical Capacitor. The baseline power system configuration selected is a series system employing peak-power-tracking for a Low Earth-Orbiting application. Power processing, required in the motor/generator, provides a potential alternative configurations that can only be achieved in systems with electrochemical energy storage by the addition of power processing components. One such alternative configuration provides for peak-power-tracking of the solar array and still maintains a regulated bus, without the expense of additional power processing components. Precise speed control of the two counterrotating wheels is required to reduce interaction with the attitude control system (ACS) or alternatively, used to perform attitude control functions. Critical technologies identified are those pertaining to the energy storage element and are prioritized as composite wheel development, magnetic suspension, motor/generator, containment, and momentum control. Comparison with a 3-kW, 250-Vdc power system using either NiCd or NiH2 for energy storage results in a system in which inertial energy storage offers potential advantages in lifetime, operating temperature, voltage regulation, energy density, charge control, and overall system weight reduction.

  10. Assessment of flywheel energy storage for spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Rodriguez, G. E.; Studer, P. A.; Baer, D. A.

    1983-01-01

    The feasibility of inertial energy storage in a spacecraft power system is evaluated on the basis of a conceptual integrated design that encompasses a composite rotor, magnetic suspension, and a permanent magnet (PM) motor/generator for a 3-kW orbital average payload at a bus distribution voltage of 250 volts dc. The conceptual design, which evolved at the Goddard Space Flight Center (GSFC), is referred to as a Mechanical Capacitor. The baseline power system configuration selected is a series system employing peak-power-tracking for a Low Earth-Orbiting application. Power processing, required in the motor/generator, provides a potential alternative configurations that can only be achieved in systems with electrochemical energy storage by the addition of power processing components. One such alternative configuration provides for peak-power-tracking of the solar array and still maintains a regulated bus, without the expense of additional power processing components. Precise speed control of the two counterrotating wheels is required to reduce interaction with the attitude control system (ACS) or alternatively, used to perform attitude control functions. Critical technologies identified are those pertaining to the energy storage element and are prioritized as composite wheel development, magnetic suspension, motor/generator, containment, and momentum control. Comparison with a 3-kW, 250-Vdc power system using either NiCd or NiH2 for energy storage results in a system in which inertial energy storage offers potential advantages in lifetime, operating temperature, voltage regulation, energy density, charge control, and overall system weight reduction.

  11. 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.

  12. System analysis of global space power problem

    NASA Astrophysics Data System (ADS)

    Latyshev, Leonid

    A brief discussion of Space Power System development problems is presented. Topics covered include the following: solar energy utilization; solar energy concentrators and receivers; solar electric power plants; thermonuclear electric power plants; energy transmission; and lunar bases.

  13. Characteristic Analysis of DC Electric Railway Systems with Superconducting Power Cables Connecting Power Substations

    NASA Astrophysics Data System (ADS)

    Ohsaki, H.; Matsushita, N.; Koseki, T.; Tomita, M.

    2014-05-01

    The application of superconducting power cables to DC electric railway systems has been studied. It could leads to an effective use of regenerative brake, improved energy efficiency, effective load sharing among the substations, etc. In this study, an electric circuit model of a DC feeding system is built and numerical simulation is carried out using MATLAB-Simulink software. A modified electric circuit model with an AC power grid connection taken into account is also created to simulate the influence of the grid connection. The analyses have proved that a certain amount of energy can be conserved by introducing superconducting cables, and that electric load distribution and concentration among the substations depend on the substation output voltage distribution.

  14. The Wild Aviolyt AC 1/Aviotab TA 2 - A computer controlled photogrammetric system

    NASA Astrophysics Data System (ADS)

    Kreiling, W.; Hasler, A.

    1980-10-01

    The Aviolyt AC 1/Aviotab TA 2 is designed to meet the highest requirements of photogrammetry in precision, flexibility, economy and reliability while also handling problems in the area of research and in the university. There are three basic components, an optical-mechanical unit with an integrated computer console, an electronics cabinet with the process computer, and the TA 2 digital-servo plotting table. The applications of the system are expanded by a wide range of accessories including a zoom system, plotting tools, and a magnetic tape unit among others. The computer software incorporates an operation system, a program library and a series of accessory programs that edit, interpret and debug. The system software is designed under principles of interactive operation, with several programs having individual logical unity.

  15. Uninterruptible power supply (UPS) systems

    SciTech Connect

    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.

  16. System and method for advanced power management

    DOEpatents

    Atcitty, Stanley; Symons, Philip C.; Butler, Paul C.; Corey, Garth P.

    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.

  17. 21 CFR 880.5510 - Non-AC-powered patient lift.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... hydraulic, battery, or mechanically powered device, either fixed or mobile, used to lift and transport a.... The device includes straps and a sling to support the patient. (b) Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of...

  18. Artificial Intelligence and Spacecraft Power Systems

    NASA Technical Reports Server (NTRS)

    Dugel-Whitehead, Norma R.

    1997-01-01

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

  19. Costing the satellite power system

    NASA Technical Reports Server (NTRS)

    Hazelrigg, G. A., Jr.

    1978-01-01

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

  20. 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

  1. Lead/acid batteries in systems to improve power quality

    NASA Astrophysics Data System (ADS)

    Taylor, P.; Butler, P.; Nerbun, W.

    Increasing dependence on computer technology is driving needs for extremely high-quality power to prevent loss of information, material, and workers' time that represent billions of dollars annually. This cost has motivated commercial and Federal research and development of energy storage systems that detect and respond to power-quality failures in milliseconds. Electrochemical batteries are among the storage media under investigation for these systems. Battery energy storage systems that employ either flooded lead/acid or valve-regulated lead/acid battery technologies are becoming commercially available to capture a share of this emerging market. Cooperative research and development between the US Department of Energy and private industry have led to installations of lead/acid-based battery energy storage systems to improve power quality at utility and industrial sites and commercial development of fully integrated, modular battery energy storage system products for power quality. One such system by AC Battery Corporation, called the PQ2000, is installed at a test site at Pacific Gas and Electric Company (San Ramon, CA, USA) and at a customer site at Oglethorpe Power Corporation (Tucker, GA, USA). The PQ2000 employs off-the-shelf power electronics in an integrated methodology to control the factors that affect the performance and service life of production-model, low-maintenance, flooded lead/acid batteries. This system, and other members of this first generation of lead/acid-based energy storage systems, will need to compete vigorously for a share of an expanding, yet very aggressive, power quality market.

  2. Large autonomous spacecraft electrical power system (LASEPS)

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  3. Solar-powered cooling system

    SciTech Connect

    Farmer, Joseph C.

    2015-07-28

    A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

  4. Study of multi-megawatt technology needs for photovoltaic space power systems, volume 2

    NASA Technical Reports Server (NTRS)

    Peterson, D. M.; Pleasant, R. L.

    1981-01-01

    Possible missions requiring multimegawatt photovoltaic space power systems in the 1990's time frame and power system technology needs associated with these missions are examined. Four specific task areas were considered: (1) missions requiring power in the 1-10 megawatt average power region; (2) alternative power systems and component technologies; (3) technology goals and sensitivity trades and analyses; and (4) technology recommendations. Specific concepts for photovoltaic power approaches considered were: planar arrays, concentrating arrays, hybrid systems using Rankine engines, thermophotovoltaic approaches; all with various photovoltaic cell component technologies. Various AC/DC power management approaches, and battery, fuel cell, and flywheel energy storage concepts are evaluated. Interactions with the electrical ion engine injection and stationkeeping system are also considered.

  5. 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

  6. Composite rod insulators for ac power lines; Electrical performance of various designs at a coastal testing station

    SciTech Connect

    Houlgate, R.G.; Swift, D.A. )

    1990-10-01

    The electrical performance of thirty-six composite insulators - of four commercial types for each AC system level of 34.5 kV, 230 kV and 500 kV - has been determined at the CEGB insulator testing station, Brighton, England. The weathershed materials were epoxy-resin, ethylene propylene rubber and silicone rubber; half of the 230 kV insulators had no stress rings. Surface leakage current was recorded for surge levels of 25 mA, 150 mA and 500 mA; a special technique was developed to obtain the flashover statistics of the 500 kV insulators, thereby enabling performance of the composite insulator to be quantified relative to that of a string of cap and pin porcelain insulators of anti-fog design, the deterioration of the insulators was observed by making regular visual inspections. The practical consequences of the findings and the causes of the degradation are discussed.

  7. Options for Affordable Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

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

  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. 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.

  10. Energy storage in remote area power supply (RAPS) systems

    NASA Astrophysics Data System (ADS)

    Moseley, Patrick T.

    Preliminary cost analyses indicate that hybrid RAPS systems are more economically attractive as a means to provide electricity to remote villages than are alternatives such as 24 h diesel generation. A hybrid remote area power supply (RAPS) system is being deployed to provide 24 h electricity to villages in the Amazon region of Peru. The RAPS system consists of modules designed to provide 150 kWh per day of utility grade ac electricity over a 24 h period. Each module contains a diesel generator, battery bank using heavy-duty 2 V VRLA gelled electrolyte batteries, a battery charger, a photovoltaic array and an inverter. Despite early difficulties, the system in the first village has now commenced operation and the promise of RAPS schemes as a means for providing sustainable remote electrification appears to be bright.

  11. 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.

  12. The sluggs survey: HST/ACS mosaic imaging of the NGC 3115 globular cluster system

    SciTech Connect

    Jennings, Zachary G.; Romanowsky, Aaron J.; Brodie, Jean P.; Arnold, Jacob A.; Strader, Jay; Lin, Dacheng; Irwin, Jimmy A.; Wong, Ka-Wah; Sivakoff, Gregory R.

    2014-08-01

    We present Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) g and z photometry and half-light radii R {sub h} measurements of 360 globular cluster (GC) candidates around the nearby S0 galaxy NGC 3115. We also include Subaru/Suprime-Cam g, r, and i photometry of 421 additional candidates. The well-established color bimodality of the GC system is obvious in the HST/ACS photometry. We find evidence for a 'blue tilt' in the blue GC subpopulation, wherein the GCs in the blue subpopulation get redder as luminosity increases, indicative of a mass-metallicity relationship. We find a color gradient in both the red and blue subpopulations, with each group of clusters becoming bluer at larger distances from NGC 3115. The gradient is of similar strength in both subpopulations, but is monotonic and more significant for the blue clusters. On average, the blue clusters have ∼10% larger R {sub h} than the red clusters. This average difference is less than is typically observed for early-type galaxies but does match that measured in the literature for the Sombrero Galaxy (M104), suggesting that morphology and inclination may affect the measured size difference between the red and blue clusters. However, the scatter on the R {sub h} measurements is large. We also identify 31 clusters more extended than typical GCs, which we term ultra-compact dwarf (UCD) candidates. Many of these objects are actually considerably fainter than typical UCDs. While it is likely that a significant number will be background contaminants, six of these UCD candidates are spectroscopically confirmed as NGC 3115 members. To explore the prevalence of low-mass X-ray binaries in the GC system, we match our ACS and Suprime-Cam detections to corresponding Chandra X-ray sources. We identify 45 X-ray-GC matches: 16 among the blue subpopulation and 29 among the red subpopulation. These X-ray/GC coincidence fractions are larger than is typical for most GC systems, probably due to the increased depth of

  13. Modeling Photovoltaic Module-Level Power Electronics in the System Advisor Model; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-07-01

    Module-level power electronics, such as DC power optimizers, microinverters, and those found in AC modules, are increasing in popularity in smaller-scale photovoltaic (PV) systems as their prices continue to decline. Therefore, it is important to provide PV modelers with guidelines about how to model these distributed power electronics appropriately in PV modeling software. This paper extends the work completed at NREL that provided recommendations to model the performance of distributed power electronics in NREL’s popular PVWatts calculator [1], to provide similar guidelines for modeling these technologies in NREL's more complex System Advisor Model (SAM). Module-level power electronics - such as DC power optimizers, microinverters, and those found in AC modules-- are increasing in popularity in smaller-scale photovoltaic (PV) systems as their prices continue to decline. Therefore, it is important to provide PV modelers with guidelines about how to model these distributed power electronics appropriately in PV modeling software.

  14. 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.

  15. 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.

  16. A distributed control approach for power and energy management in a notional shipboard power system

    NASA Astrophysics Data System (ADS)

    Shen, Qunying

    The main goal of this thesis is to present a power control module (PCON) based approach for power and energy management and to examine its control capability in shipboard power system (SPS). The proposed control scheme is implemented in a notional medium voltage direct current (MVDC) integrated power system (IPS) for electric ship. To realize the control functions such as ship mode selection, generator launch schedule, blackout monitoring, and fault ride-through, a PCON based distributed power and energy management system (PEMS) is developed. The control scheme is proposed as two-layer hierarchical architecture with system level on the top as the supervisory control and zonal level on the bottom as the decentralized control, which is based on the zonal distribution characteristic of the notional MVDC IPS that was proposed as one of the approaches for Next Generation Integrated Power System (NGIPS) by Norbert Doerry. Several types of modules with different functionalities are used to derive the control scheme in detail for the notional MVDC IPS. Those modules include the power generation module (PGM) that controls the function of generators, the power conversion module (PCM) that controls the functions of DC/DC or DC/AC converters, etc. Among them, the power control module (PCON) plays a critical role in the PEMS. It is the core of the control process. PCONs in the PEMS interact with all the other modules, such as power propulsion module (PPM), energy storage module (ESM), load shedding module (LSHED), and human machine interface (HMI) to realize the control algorithm in PEMS. The proposed control scheme is implemented in real time using the real time digital simulator (RTDS) to verify its validity. To achieve this, a system level energy storage module (SESM) and a zonal level energy storage module (ZESM) are developed in RTDS to cooperate with PCONs to realize the control functionalities. In addition, a load shedding module which takes into account the reliability

  17. Eri silkworm (Samia ricini), a non-mulberry host system for AcMNPV mediated expression of recombinant proteins.

    PubMed

    Hosamani, Madhusudan; Basagoudanavar, Suresh H; Sreenivasa, B P; Inumaru, Shigeki; Ballal, Chandish R; Venkataramanan, Ramamurthy

    2015-12-20

    The baculovirus expression system (BVES) based on Autographa californica nucleopolyhedrovirus (AcMNPV) is widely used for the expression of eukaryotic proteins. Several insect cells/larvae that are permissive to AcMNPV have been routinely used as hosts to express heterologous proteins. Domesticated Eri silkworm (Samia ricini), reared in many parts of India, Japan and China, is a non-mulberry silkworm. The present study shows that the Eri silkworm larvae are susceptible to intra-haemocoelical inoculation of AcMNPV. The virus replicates in the larva, as indicated by an increased viral loads in the haemolymph upon injection of a recombinant AcMNPV carrying green fluorescent protein gene. The virus showed localized replication in different tissues including the fat body, haemocytes, tracheal matrix and in the Malphigian tubules. The larval system was successfully used to express heterologous protein, by infecting with a recombinant AcMNPV carrying the 3ABC coding sequence of foot-and-mouth disease virus (FMDV). The study shows that the Eri silkworm larva can be a potential alternative bioreactor, for scaling up of the recombinant proteins employing the baculovirus system. PMID:26467714

  18. Materials in space nuclear power systems

    SciTech Connect

    Cooper, R.H.; Moore, J.P.

    1991-01-01

    Man's presence in space has been limited by the availability of reliable lightweight sources of power. Over the course of the last 30 years, a variety of space nuclear power systems have been designed and, in some cases, built and flown. Although a number of technology issues effect the overall performance of these systems, technical issues associated with the materials of construction have most often been a major limitation in obtaining the desired system performance goals. This paper will review selected materials limitations associated with the three major nuclear power systems being considered at this time: radioisotope power, nuclear power, and nuclear propulsion systems.

  19. Indirect Adaptive Fuzzy Power System Stabilizer

    NASA Astrophysics Data System (ADS)

    Saoudi, Kamel; Bouchama, Ziad; Harmas, Mohamed Naguib; Zehar, Khaled

    2008-06-01

    A power system stabilizer based on adaptive fuzzy technique is presented. The design of a fuzzy logic power system stabilizer (FLPSS) requires the collection of fuzzy IF-THEN rules which are used to initialize an adaptive fuzzy power system AFPSS. The rule-base can be then tuned on-line so that the stabilizer can adapt to the different operating conditions occurring in the power system. The adaptation laws are developed based on a Lyapunov synthesis approach. Assessing the validity of this technique simulation of a power system is conducted and results are discussed.

  20. Progress on PEP-II magnet power conversion system

    SciTech Connect

    Bellomo, P.; Genova, L.; Jackson, T.; Shimer, D.

    1996-06-04

    The various power systems for supplying the PEP-II DC magnets rely exclusively on switchmode conversion, utilizing a variety of means depending on the requirements. All of the larger power supplies, ranging from 10 to 200 kW, are powered from DC sources utilizing rectified 480 V AC. Choppers can be used for the series connected strings, but for smaller groups and individual magnets, inverters driving high-frequency transformers with rectifiers comprise the best approach. All of the various systems use a ``building block`` approach of multiple standard-size units connected in series or parallel to most cost-effectively deal with a great range of voltage and current requirements. Utilization of existing infrastructure from PEP-I has been a cost-effective determinant. Equipment is being purchased either off-the-shelf, through performance specification, or by hardware purchase based on design-through-prototype. The corrector magnet power system, utilizing inexpensive, off-the-shelf, four-quadrant switching motor-controllers, has already proven very reliable: 120 of the total of 900 units have been running on the injection system for four months with no failures.

  1. Coordinated power control of unified power flow controller and its application for enhancing dynamic power system performance

    NASA Astrophysics Data System (ADS)

    Fang, Wanliang

    This thesis focuses on reporting my research study on a problem area relating to use of Unified Power Flow Controller (UPFC) for coordinating load flow in power systems so as to enhance their static and dynamic performance by having more secure and economical operation and higher dynamic stability margin. UPFC is considered as one of the most promising devices for implementing the Flexible AC Transmission System (FACTS) concept. Although development of UPFC is still on an infant stage, probing into its impact on power system operation is actively pursued and significant effort has been devoted to put it forward as a practical FACTS device and as a challenging academic research object. In order to consider UPFC as a basic power system element, it has to be involved in associated load flow computation essentially for power system control analysis and operational planning. An up front problem for design engineers is therefore pointing to a need to modify existing load flow program so as to accommodate interactions of UPFCs. A lot of research output start coming out but their computational efficiency are not high enough. In this regard, I propose two methods to perform the UPFC embedded load flow calculation to cater for two different types of application. The first one caters for analyzing direct control of load flow on transmission lines with embedded UPFCs. In this type of problem, active and reactive power of the lines, as well as the magnitude of bus voltages are priori given. The load flow solution can then be obtained and enables the UPFC parameters to be determined with a significantly improved computational efficiency. The second one works in contrary to the first one by which parameters of UPFCs are given before hand and the load flow calculation is performed for conforming a feasible operation. It can be regarded as an indirect load flow control calculation which is useful in planning stage for incorporating UPFC into existing system and/or carrying out

  2. Tailoring SCADA systems for standby power applications

    SciTech Connect

    Leslie, D.; Hlushko, A.; Abughazaleh, S.; Garza, F.

    1994-04-01

    Supervisory control and data acquisition (SCADA) systems have been used by the manufacturing and process industries and many electric power utilities for energy management systems, including economic dispatch and the interconnection processing of energy. However, the use of SCADA in smaller power generation systems is not quite so wide spread. This article explains how a SCADA system was custom developed for a stand-by power generation system recently installed in a commercial office building.

  3. Improving the efficiency of solar photovoltaic power system

    NASA Astrophysics Data System (ADS)

    Aribisala, Henry A.

    As the local and national clamor for foreign energy independent United States continues to grow unabated; renewable energy has been receiving increased focus and it's widely believed that it's not only the answer to ever increasing demand for energy in this country, but also the environmentally friendly means of meeting such demand. During the spring of 2010, I was involved with a 5KW solar power system design project; the project involved designing and building solar panels and associated accessories like the solar array mounts and Solar Inverter system. One of the key issues we ran into during the initial stage of the project was how to select efficient solar cells for panel building at a reasonable cost. While we were able to purchase good solar cells within our allocated budget, the issue of design for efficiency was not fully understood , not just in the contest of solar cells performance , but also in the overall system efficiency of the whole solar power system, hence the door was opened for this thesis. My thesis explored and expanded beyond the scope of the aforementioned project to research different avenues for improving the efficiency of solar photo-voltaic power system from the solar cell level to the solar array mounting, array tracking and DC-AC inversion system techniques.

  4. Grid-Tied Photovoltaic Power System

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.

    2011-01-01

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

  5. Power conditioning system modelling for nuclear electric propulsion

    NASA Astrophysics Data System (ADS)

    Metcalf, Kenneth J.

    1993-11-01

    NASA LeRC is currently developing a Fortran based model of a complete nuclear electric propulsion (NEP) vehicle that would be used for piloted and cargo missions to the Moon or Mars. The proposed vehicle design will use either a Brayton or K-Rankine power conversion cycle to drive a turbine coupled with a rotary alternator. Two thruster types are also being studied, ion and magnetoplasmadynamic (MPD). In support of this NEP model, Rocketdyne developed a power management and distribution (PMAD) subroutine that provides parametric outputs for selected alternator operating voltages and frequencies, thruster types, system power levels, and electronics coldplate temperatures. The end-to-end PMAD model described is based on the direct use of the alternator voltage and frequency for transmitting power to either ion or MPD thrusters. This low frequency transmission approach was compared with dc and high frequency ac designs, and determined to have the lowest mass, highest efficiency, highest reliability and lowest development costs. While its power quality is not as good as that provided by a high frequency system, it was considered adequate for both ion and MPD engine applications. The low frequency architecture will be used as the reference in future NEP PMAD studies.

  6. Power Conditioning System Modelling for Nuclear Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Metcalf, Kenneth J.

    1993-01-01

    NASA LeRC is currently developing a Fortran based model of a complete nuclear electric propulsion (NEP) vehicle that would be used for piloted and cargo missions to the Moon or Mars. The proposed vehicle design will use either a Brayton or K-Rankine power conversion cycle to drive a turbine coupled with a rotary alternator. Two thruster types are also being studied, ion and magnetoplasmadynamic (MPD). In support of this NEP model, Rocketdyne developed a power management and distribution (PMAD) subroutine that provides parametric outputs for selected alternator operating voltages and frequencies, thruster types, system power levels, and electronics coldplate temperatures. The end-to-end PMAD model described is based on the direct use of the alternator voltage and frequency for transmitting power to either ion or MPD thrusters. This low frequency transmission approach was compared with dc and high frequency ac designs, and determined to have the lowest mass, highest efficiency, highest reliability and lowest development costs. While its power quality is not as good as that provided by a high frequency system, it was considered adequate for both ion and MPD engine applications. The low frequency architecture will be used as the reference in future NEP PMAD studies.

  7. The physics of power systems operation

    NASA Astrophysics Data System (ADS)

    Ohler, C.

    2015-08-01

    The article explains the operation of power systems from the point of view of physics. Physicists imagine things, rather than in terms of impedances and circuits, in terms of fields and energy conversions. The account is concrete and simple. The use of alternating current entails the issue of reactive power. Reactive power consists of energy that oscillates between electrical and magnetic fields, it flows on top of the active power which carries the useful energy. The control of active and reactive power is essential for the power system's reliable operation. The frequency of a power system is the same everywhere. The stability of the frequency indicates that generation and demand of active power are equal, a decline in frequency indicates a lack of generation relative to the demand. Adapting the electrical power injected into the system is the way of frequency control. Because of the parasitic inductances and capacitances of overhead lines, cables, and transformers, the voltage at different locations of the power system depends on the load. The voltage is regulated by the combined action of generator excitation, transformer tap changers and series compensation in order to provide consumers with a stable voltage supply. The integration of solar cells and wind turbines into the power system poses some challenges. But the power system is able to accommodate large amounts of fluctuating renewable power generation if the right complementary measures are taken.

  8. An adaptive neuro fuzzy inference system controlled space cector pulse width modulation based HVDC light transmission system under AC fault conditions

    NASA Astrophysics Data System (ADS)

    Ajay Kumar, M.; Srikanth, N. V.

    2014-03-01

    In HVDC Light transmission systems, converter control is one of the major fields of present day research works. In this paper, fuzzy logic controller is utilized for controlling both the converters of the space vector pulse width modulation (SVPWM) based HVDC Light transmission systems. Due to its complexity in the rule base formation, an intelligent controller known as adaptive neuro fuzzy inference system (ANFIS) controller is also introduced in this paper. The proposed ANFIS controller changes the PI gains automatically for different operating conditions. A hybrid learning method which combines and exploits the best features of both the back propagation algorithm and least square estimation method is used to train the 5-layer ANFIS controller. The performance of the proposed ANFIS controller is compared and validated with the fuzzy logic controller and also with the fixed gain conventional PI controller. The simulations are carried out in the MATLAB/SIMULINK environment. The results reveal that the proposed ANFIS controller is reducing power fluctuations at both the converters. It also improves the dynamic performance of the test power system effectively when tested for various ac fault conditions.

  9. Red Leak Effects in Observations of Solar System Objects with ACS/SBC

    NASA Astrophysics Data System (ADS)

    Feldman, Paul D.; Weaver, Harold A.; Saur, Joachim; McGrath, Melissa A.

    2010-07-01

    Following the failure of STIS in August 2004, attempts to obtain ultraviolet spectroscopy and photometry of solar system objects shifted to the Solar Blind Channel (SBC) of the ACS. These included spatially resolved spectroscopy using the PR130L prism of comet 9P/Tempel 1 (at the time of Deep Impact) and Europa, and imaging and photometry of the asteroid 21 Lutetia, one of the targets of ESA's Rosetta mission. Initial estimates of long wavelength ("red") contamination of the data due to impurities in the FUV MAMA detector suggested that these observations were feasible. Subsequent analyses produced better sampled, more reliable response curves that showed the long wavelength response to be much worse than expected. The data from the Europa and Lutetia observations confirm this conclusion and provide additional quantitative measurements of the magnitude of the "red leak."

  10. Dynamics of energy transport and entropy production in ac-driven quantum electron systems

    NASA Astrophysics Data System (ADS)

    Ludovico, María Florencia; Moskalets, Michael; Sánchez, David; Arrachea, Liliana

    2016-07-01

    We analyze the time-resolved energy transport and the entropy production in ac-driven quantum coherent electron systems coupled to multiple reservoirs at finite temperature. At slow driving, we formulate the first and second laws of thermodynamics valid at each instant of time. We identify heat fluxes flowing through the different pieces of the device and emphasize the importance of the energy stored in the contact and central regions for the second law of thermodynamics to be instantaneously satisfied. In addition, we discuss conservative and dissipative contributions to the heat flux and to the entropy production as a function of time. We illustrate these ideas with a simple model corresponding to a driven level coupled to two reservoirs with different chemical potentials.

  11. 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.

  12. 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

  13. Solid state remote power controllers for 120 Vdc power systems

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  14. Bidirectional Five-Level Power Processing Interface for Low Voltage Battery Energy Storage System

    NASA Astrophysics Data System (ADS)

    Huang, Jain-Yi; Jou, Hurng-Liahng; Wu, Kuen-Der; Lin, You-Si; Wu, Jinn-Chang

    A bidirectional five-level power processing interface for low voltage battery energy storage system (BESS) is developed in this paper. This BESS consists of a bidirectional five-level DC-AC converter, a bidirectional dual boost/buck DC-DC converter and a battery set. This five-level DC-AC converter includes a bidirectional full-bridge converter and a bidirectional dual buck DC-DC converter. The five-level power processing interface can charge power to the battery set form the utility or discharge the power from the battery set to the utility depending on the demanded operation of user. A hardware prototype is developed to verify the performance of this BESS. Experimental results show the performance of the developed BESS is as expected.

  15. Hubble Space Telescope electrical power system model

    NASA Technical Reports Server (NTRS)

    Baggett, Randy; Miller, Jim; Leisgang, Tom

    1988-01-01

    This paper describes one of the most comprehensive models ever developed for a spacecraft electrical power system (EPS). The model was developed for the Hubble Space Telescope (HST) to evaluate vehicle power system performance and to assist in scheduling maintenance and refurbishment missions by providing data needed to forecast EPS power and energy margins for the mission phases being planned. The EPS model requires a specific mission phase description as the input driver and uses a high granularity database to produce a multi-orbit power system performance report. The EPS model accurately predicts the power system response to various mission timelines over the entire operational life of the spacecraft.

  16. 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.

  17. Performance analysis of radiation cooled dc transmission lines for high power space systems

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.

    1985-01-01

    As space power levels increase to meet mission objectives and also as the transmission distance between power source and load increases, the mass, volume, power loss, and operating voltage and temperature become important system design considerations. This analysis develops the dependence of the specific mass and percent power loss on the power and voltage levels, transmission distance, operating temperature and conductor material properties. Only radiation cooling is considered since the transmission line is assumed to operate in a space environment. The results show that the limiting conditions for achieving low specific mass, percent power loss, and volume for a space-type dc transmission line are the permissible transmission voltage and operating temperature. Other means to achieve low specific mass include the judicious choice of conductor materials. The results of this analysis should be immediately applicable to power system trade-off studies including comparisons with ac transmission systems.

  18. Performance analysis of radiation cooled dc transmission lines for high power space systems

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.

    1985-01-01

    As space power levels increase to meet mission objectives and also as the transmission distance between power source and load increases, the mass, volume, power loss, and operating voltage and temperature become important system design considerations. This analysis develops the dependence of the specific mass and percent power loss on hte power and voltage levels, transmission distance, operating temperature and conductor material properties. Only radiation cooling is considered since the transmission line is assumed to operate in a space environment. The results show that the limiting conditions for achieving low specific mass, percent power loss, and volume for a space-type dc transmission line are the permissible transmission voltage and operating temperature. Other means to achieve low specific mass include the judicious choice of conductor materials. The results of this analysis should be immediately applicable to power system trade-off studies including comparisons with ac transmission systems.

  19. Cooling systems and hybrid A/C systems using an electromagnetic radiation-absorbing complex

    SciTech Connect

    Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

    2015-05-19

    A method for powering a cooling unit. The method including applying electromagnetic (EM) radiation to a complex, where the complex absorbs the EM radiation to generate heat, transforming, using the heat generated by the complex, a fluid to vapor, and sending the vapor from the vessel to a turbine coupled to a generator by a shaft, where the vapor causes the turbine to rotate, which turns the shaft and causes the generator to generate the electric power, wherein the electric powers supplements the power needed to power the cooling unit

  20. 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.

  1. Power Management and Distribution System Developed for Thermionic Power Converters

    NASA Technical Reports Server (NTRS)

    Baez, Anastacio N.

    1998-01-01

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

  2. Power Processing for a Conceptual Project Prometheus Electric Propulsion System

    NASA Technical Reports Server (NTRS)

    Scina, Joseph E., Jr.; Aulisio, Michael; Gerber, Scott S.; Hewitt, Frank; Miller, Leonard; Elbuluk, Malik; Pinero, Luis R. (Technical Monitor)

    2005-01-01

    NASA has proposed a bold mission to orbit and explore the moons of Jupiter. This mission, known as the Jupiter Icy Moons Orbiter (JIMO), would significantly increase NASA s capability to explore deep space by making use of high power electric propulsion. One electric propulsion option under study for JIMO is an ion propulsion system. An early version of an ion propulsion system was successfully used on NASA's Deep Space 1 mission. One concept for an ion thruster system capable of meeting the current JIMO mission requirement would have individual thrusters that are 16 to 25 kW each and require voltages as high as 8.0 kV. The purpose of this work is to develop power processing schemes for delivering the high voltage power to the spacecraft ion thrusters based upon a three-phase AC distribution system. In addition, a proposed DC-DC converter topology is presented for an ion thruster ancillary supply based upon a DC distribution system. All specifications discussed in this paper are for design convenience and are speculative in nature.

  3. Feasibility study of wireless power transmission systems

    NASA Technical Reports Server (NTRS)

    Robinson, W. J., Jr.

    1968-01-01

    Wireless microwave or laser energy transfers power from a manned earth-orbiting central station to unmanned astronomical substations. More efficient systems are required for the microwave power transmission.

  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. Power system with an integrated lubrication circuit

    SciTech Connect

    Hoff, Brian D.; Akasam, Sivaprasad; Algrain, Marcelo C.; Johnson, Kris W.; Lane, William H.

    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.

  6. Nova power systems: status and operating experience

    SciTech Connect

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

    1983-11-28

    This paper describes the pulse power systems that are used in these lasers; the status and the operating experiences. The pulsed power system for the Nova Laser is comprised of several distinct technology areas. The large capacitor banks for driving flashlamps that excite the laser glass is one area, the fast pulsers that drive pockels cell shutters is another area, and the contol system for the pulsed power is a third. This paper discusses the capacitor banks and control systems.

  7. Summary of State-of-the-Art Power Conversion Systems for Energy Storage Applications

    SciTech Connect

    Atcitty, S.; Gray-Fenner, A.; Ranade, S.

    1998-09-01

    The power conversion system (PCS) is a vital part of many energy storage systems. It serves as the interface between the storage device, an energy source, and an AC load. This report summarizes the results of an extensive study of state-of-the-art power conversion systems used for energy storage applications. The purpose of the study was to investigate the potential for cost reduction and performance improvement in these power conversion systems and to provide recommendations for fiture research and development. This report provides an overview of PCS technology, a description of several state-of-the-art power conversion systems and how they are used in specific applications, a summary of four basic configurations for l:he power conversion systems used in energy storage applications, a discussion of PCS costs and potential cost reductions, a summary of the stancku-ds and codes relevant to the technology, and recommendations for future research and development.

  8. Power Coupling Alternatives for the NEP Thermionic Power System

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  9. 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.

  10. Development of an in-line filter to prevent intrusion of NO2 toxic vapors into A/C systems

    NASA Technical Reports Server (NTRS)

    Meneghelli, Barry; Mcnulty, R. J.; Springer, Mike; Lueck, Dale E.

    1995-01-01

    The hypergolic propellant nitrogen tetroxide (N2O4 or NTO) is routinely used in spacecraft launched at Kennedy Space Center (KSC) and Cape Canaveral Air Station (CCAS). In the case of a catastrophic failure of the spacecraft, there would be a release of the unspent propellant in the form of a toxic cloud. Inhalation of this material at downwind concentrations which may be as high as 20 parts per million (ppm) for 30 minutes in duration, may produce irritation to the eyes, nose and respiratory tract. Studies at both KSC and CCAS have shown that the indoor concentrations of N2O4 during a toxic release may range from 1 to 15 ppm and depend on the air change rate (ACR) for a particular building and whether or not the air conditioning (A/C) system has been shut down or left in an operating mode. This project was initiated in order to assess how current A/C systems could be easily modified to prevent personnel from being exposed to toxic vapors. A sample system has been constructed to test the ability of several types of filter material to capture the N2O4 vapors prior to their infiltration into the A/C system. Test results will be presented which compare the efficiencies of standard A/C filters, water wash systems, and chemically impregnated filter material in taking toxic vapors out of the incoming air stream.

  11. Feasibility studies of a power interconnection system for Central American countries: SIEPAC project

    SciTech Connect

    Gomez, T.; Enamorado, J.C. . Inst. de Investigacion Tecnologica); Vela, A. )

    1994-06-01

    The electrical systems of the Central American countries are linked by 230 kV ac weak border interconnections forming two separated subsystems. The first one includes Guatemala and El Salvador, and the other one comprises the systems of Honduras, Nicaragua, Costa Rica, and Panama. As a consequence, unrestricted energy exchanges among all countries are not possible. This article describes the SIEPAC project which consists of a 1,678 km long 500 kV ac power transmission line that would link the six electrical systems of the region through seven power substations (one for each country and two in Panama), installed close to the highest demand national centers and six control centers of energy (one for each country) to allow coordinated operation of the interconnection.This project also considers a set of complementary assets (230 ac power transmission lines into some countries and the border transmission line between El Salvador and Honduras, and various other equipment). The power transmission line will greatly reinforce the actual border interconnections, which have a reduced capacity of exchange and technical problems associated with the stability of a weak longitudinal system. On the other hand, economic savings for the region would be achieved, coming from a higher coordination level in the operation and planning of their systems.

  12. 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

  13. Establishment and application of a loop-mediated isothermal amplification (LAMP) system for detection of cry1Ac transgenic sugarcane

    PubMed Central

    Zhou, Dinggang; Guo, Jinlong; Xu, Liping; Gao, Shiwu; Lin, Qingliang; Wu, Qibin; Wu, Luguang; Que, Youxiong

    2014-01-01

    To meet the demand for detection of foreign genes in genetically modified (GM) sugarcane necessary for regulation of gene technology, an efficient method with high specificity and rapidity was developed for the cry1Ac gene, based on loop-mediated isothermal amplification (LAMP). A set of four primers was designed using the sequence of cry1Ac along with optimized reaction conditions: 5.25 mM of Mg2+, 4:1 ratio of inner primer to outer primer, 2.0 U of Bst DNA polymerase in a reaction volume of 25.0 μL. Three post-LAMP detection methods (precipitation, calcein (0.60 mM) with Mn2+ (0.05 mM) complex and SYBR Green I visualization), were shown to be effective. The sensitivity of the LAMP method was tenfold higher than that of conventional PCR when using templates of the recombinant cry1Ac plasmid or genomic DNA from cry1Ac transgenic sugarcane plants. More importantly, this system allowed detection of the foreign gene on-site when screening GM sugarcane without complex and expensive instruments, using the naked eye. This method can not only provide technological support for detection of cry1Ac, but can also further facilitate the use of this detection technique for other transgenes in GM sugarcane. PMID:24810230

  14. Combustion powered thermophotovoltaic emitter system

    SciTech Connect

    McHenry, R.S.; Harper, M.J.; Lindler, K.W.

    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.

  15. Wave activated power generation system

    SciTech Connect

    Ono, Y.

    1983-08-09

    A wave activated power generation system of the float type is disclosed, comprising at least one piston-cylinder device having an anchored cylinder and a piston slidable in the cylinder and cooperating with the cylinder to form a pumping chamber above the piston and a low pressure chamber below the piston. The cylinder has an intake port and an exhaust port both formed at an upper port thereof to communicate with the pumping chamber and each provided with a check valve. A float is connected through a cable to the piston of the piston- cylinder device. A pair of fluid storages are connected to the intake port and the exhaust port of the pumping chamber, respectively. A waterwheel generator is driven by the fluid flowing from one of the fluid storages to another. A pressure regulating device is connected to the low pressure chamber so as to maintain the low pressure chamber at a pressure lower than the pressure in the pumping chamber, the difference in pressure ceaselessly applying a downward force on the piston to keep the cable in a tensed condition.

  16. N-Terminal Acetylation-Targeted N-End Rule Proteolytic System: The Ac/N-End Rule Pathway

    PubMed Central

    Lee, Kang-Eun; Heo, Ji-Eun; Kim, Jeong-Mok; Hwang, Cheol-Sang

    2016-01-01

    Although Nα-terminal acetylation (Nt-acetylation) is a pervasive protein modification in eukaryotes, its general functions in a majority of proteins are poorly understood. In 2010, it was discovered that Nt-acetylation creates a specific protein degradation signal that is targeted by a new class of the N-end rule proteolytic system, called the Ac/N-end rule pathway. Here, we review recent advances in our understanding of the mechanism and biological functions of the Ac/N-end rule pathway, and its crosstalk with the Arg/N-end rule pathway (the classical N-end rule pathway). PMID:26883906

  17. Loop gain of a spacecraft switched shunt power system

    NASA Astrophysics Data System (ADS)

    Wu, Keng

    1994-10-01

    A novel approach of deriving the loop gain of a spacecraft switched shunt power system is presented. The system hardware elements contain both the analog and the digital components. Transfer functions of the analog circuits are easily identified employing the conventional approach. Gain function of the digital block is however conceived following a quite unconventional route. The digital gain is shown to include the effects of comparator thresholds, digital clock, shift register, sinusoidal amplitude, and ac frequency. The dependence of the digital gain on voltage thresholds, clocking period, and the integrational property of threshold comparator is expected. The dependence on sinusoidal amplitude contradicts the traditional concept of small signal analysis. The overall loop gain in the analytic form yields a computational result that matches the actual measurement very well. This fact proves, to some extent, the validity of the digital gain function and the basis of its derivation.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Space-to-earth power transmission system

    NASA Technical Reports Server (NTRS)

    Stevens, G. H.; Schuh, R.

    1976-01-01

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

  5. Flexibility in 21st Century Power Systems

    SciTech Connect

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

    2014-05-01

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

  6. 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.

  7. Power line monitoring system using fiber optic power supply

    NASA Astrophysics Data System (ADS)

    Tanaka, Yosuke; Shioda, Tatsutoshi; Kurokawa, Takashi; Oka, Junji; Ueta, Kazuyuki; Fukuoka, Toshiharu

    2009-05-01

    We propose a novel power-line-monitoring system using optical fibers for transmitting power as well as signal. The principle is experimentally confirmed with a system composed of a monitoring side with a 1.5-μm laser diode, transmission line of a single mode fiber, and a sensing side having an efficient photovoltaic (PV) cell, electrical junction sensor, and low power liquid crystal optical modulator (LCOM). The PV cell generates the electrical power in the sensing side with a conversion efficiency of 20%. The LCOM is driven with low power of less than 50 μW, modulates the laser light with a signal indicating the power line condition, and transmits the optical signal. The developed sensing unit produces an optical signal having an extinction ratio of 15 dB with low optical power of 1.8 mW. Five systems were in operation for two years, faithfully monitoring the oil pressure in electrical cables every 20 min without incident.

  8. 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.

  9. Switching System for Redundant Power Supplies

    NASA Technical Reports Server (NTRS)

    Bradford, M.; Grant, R.; Parkinson, G.

    1986-01-01

    Load-transfer unit connects airborne computer to standby power supply in case primary supply fails. Concept adaptable to systems in which power interruptions cannot be tolerated; for example, computers with volatile memories, safety equipment, and precise timers. Load-transfer unit monitors voltages and load current. Microprocessor controls transistor switches that connect load to whichever power supply has highest priority and correct voltage.

  10. 78 FR 39280 - Integrated System Power Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-01

    .... 888, 61 FR 21,540 (5/10/1996), FERC Stats. & Regs. ] 31,036 (1996), order on reh'g, Order No. 888-A, 62 FR 12,274 (3/14/ 1997), FERC Stats. & Regs. ] 31,048 (1997), order on reh'g, Order No. 888-B, 81... Southwestern Power Administration Integrated System Power Rates AGENCY: Southwestern Power Administration,...

  11. 75 FR 1363 - Integrated System Power Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-11

    ... schedule. On September 23, 2009, Southwestern published notice in the Federal Register, (74 FR 48527), of a... Register, September 23, 2009, (74 FR 48527). The consultation and comment period was shortened from the 90... Southwestern Power Administration Integrated System Power Rates AGENCY: Southwestern Power Administration,...

  12. 78 FR 62616 - Integrated System Power Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ..., Southwestern published notice in the Federal Register (78 FR 39280) of a 60-day comment period, together with a..., 2013, (78 FR 39280). The consultation and comment period was shortened from the 90 days provided for in... Southwestern Power Administration Integrated System Power Rates AGENCY: Southwestern Power Administration,...

  13. 77 FR 2521 - Integrated System Power Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ..., Southwestern published notice in the Federal Register, (76 FR 48159), of a 60-day comment period, together with... were announced by notice published in the Federal Register, August 8, 2011, (76 FR 48159). The... Southwestern Power Administration Integrated System Power Rates AGENCY: Southwestern Power Administration,...

  14. 76 FR 48159 - Integrated System Power Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-08

    ... by Public Utilities and Transmitting Utilities, Order No. 888, 61 FR 21,540 (5/10/1996), FERC Stats. & Regs. ] 31,036 (1996), order on reh'g, Order No. 888-A, 62 FR 12,274 (3/14/ 1997), FERC Stats. & Regs... Southwestern Power Administration Integrated System Power Rates AGENCY: Southwestern Power Administration,...

  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. Acceptance test report: Backup power system

    SciTech Connect

    Cole, D.B.

    1996-01-26

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

  17. 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.

  18. 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

  19. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions.

    PubMed

    Lockerbie, N A; Tokmakov, K V

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m(-1) was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain

  20. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions

    NASA Astrophysics Data System (ADS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m-1 was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain ratio

  1. Working group report on advanced high-voltage high-power and energy-storage space systems

    NASA Technical Reports Server (NTRS)

    Cohen, H. A.; Cooke, D. L.; Evans, R. W.; Hastings, D.; Jongeward, G.; Laframboise, J. G.; Mahaffey, D.; Mcintyre, B.; Pfizer, K. A.; Purvis, C.

    1986-01-01

    Space systems in the future will probably include high-voltage, high-power energy-storage and -production systems. Two such technologies are high-voltage ac and dc systems and high-power electrodynamic tethers. The working group identified several plasma interaction phenomena that will occur in the operation of these power systems. The working group felt that building an understanding of these critical interaction issues meant that several gaps in our knowledge had to be filled, and that certain aspects of dc power systems have become fairly well understood. Examples of these current collection are in quiescent plasmas and snap over effects. However, high-voltage dc and almost all ac phenomena are, at best, inadequately understood. In addition, there is major uncertainty in the knowledge of coupling between plasmas and large scale current flows in space plasmas. These gaps in the knowledge are addressed.

  2. 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.

  3. 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.

  4. A new bipolar Qtrim power supply system

    SciTech Connect

    Mi, C.; Bruno, D.; Drozd, J.; Nolan, T.; Orsatti, F.; Heppener, G.; Di Lieto, A.; Schultheiss, C.; Samms, T.; Zapasek, R.; Sandberg, J.

    2015-05-03

    This year marks the 15th run of RHIC (Relativistic Heavy Ion Collider) operations. The reliability of superconducting magnet power supplies is one of the essential factors in the entire accelerator complex. Besides maintaining existing power supplies and their associated equipment, newly designed systems are also required based on the physicist’s latest requirements. A bipolar power supply was required for this year’s main quadruple trim power supply. This paper will explain the design, prototype, testing, installation and operation of this recently installed power supply system.

  5. High power laser apparatus and system

    NASA Technical Reports Server (NTRS)

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

    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.

  6. A Power-Efficient Wireless System With Adaptive Supply Control for Deep Brain Stimulation.

    PubMed

    Lee, Hyung-Min; Park, Hangue; Ghovanloo, Maysam

    2013-09-01

    A power-efficient wireless stimulating system for a head-mounted deep brain stimulator (DBS) is presented. A new adaptive rectifier generates a variable DC supply voltage from a constant AC power carrier utilizing phase control feedback, while achieving high AC-DC power conversion efficiency (PCE) through active synchronous switching. A current-controlled stimulator adopts closed-loop supply control to automatically adjust the stimulation compliance voltage by detecting stimulation site potentials through a voltage readout channel, and improve the stimulation efficiency. The stimulator also utilizes closed-loop active charge balancing to maintain the residual charge at each site within a safe limit, while receiving the stimulation parameters wirelessly from the amplitude-shift-keyed power carrier. A 4-ch wireless stimulating system prototype was fabricated in a 0.5-μm 3M2P standard CMOS process, occupying 2.25 mm². With 5 V peak AC input at 2 MHz, the adaptive rectifier provides an adjustable DC output between 2.5 V and 4.6 V at 2.8 mA loading, resulting in measured PCE of 72 ~ 87%. The adaptive supply control increases the stimulation efficiency up to 30% higher than a fixed supply voltage to 58 ~ 68%. The prototype wireless stimulating system was verified in vitro. PMID:24678126

  7. A Power-Efficient Wireless System With Adaptive Supply Control for Deep Brain Stimulation

    PubMed Central

    Lee, Hyung-Min; Park, Hangue; Ghovanloo, Maysam

    2014-01-01

    A power-efficient wireless stimulating system for a head-mounted deep brain stimulator (DBS) is presented. A new adaptive rectifier generates a variable DC supply voltage from a constant AC power carrier utilizing phase control feedback, while achieving high AC-DC power conversion efficiency (PCE) through active synchronous switching. A current-controlled stimulator adopts closed-loop supply control to automatically adjust the stimulation compliance voltage by detecting stimulation site potentials through a voltage readout channel, and improve the stimulation efficiency. The stimulator also utilizes closed-loop active charge balancing to maintain the residual charge at each site within a safe limit, while receiving the stimulation parameters wirelessly from the amplitude-shift-keyed power carrier. A 4-ch wireless stimulating system prototype was fabricated in a 0.5-μm 3M2P standard CMOS process, occupying 2.25 mm². With 5 V peak AC input at 2 MHz, the adaptive rectifier provides an adjustable DC output between 2.5 V and 4.6 V at 2.8 mA loading, resulting in measured PCE of 72 ~ 87%. The adaptive supply control increases the stimulation efficiency up to 30% higher than a fixed supply voltage to 58 ~ 68%. The prototype wireless stimulating system was verified in vitro. PMID:24678126

  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. Nuclear Space Power Systems Materials Requirements

    SciTech Connect

    Buckman, R.W. Jr.

    2004-02-04

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

  10. Nuclear Space Power Systems Materials Requirements

    NASA Astrophysics Data System (ADS)

    Buckman, R. W.

    2004-02-01

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

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

    NASA Technical Reports Server (NTRS)

    Marriott, A. T.

    1979-01-01

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

  12. Fault-tolerant electrical power system

    NASA Astrophysics Data System (ADS)

    Mehdi, Ishaque S.; Weimer, Joseph A.

    1987-10-01

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

  13. Propulsion element requirements using electrical power system unscheduled power

    NASA Technical Reports Server (NTRS)

    Zimmermann, Frank; Hodge, Kathy

    1989-01-01

    The suitability of using the electrical energy from the Space Station's Electrical Power System (EPS) during the periods of peak solar insolation which is currently not specifically allocated (unscheduled power) to produce propulsion propellants, gaseous hydrogen, and oxygen by electrolyzing water is investigated. Reboost propellant requirements are emphasized, but the results are more generally relevant because the balance of recurring propellant requirements are an order of magnitude smaller and the nonrecurring requirements are not significant on an average basis.

  14. Solar dynamic power system definition study

    NASA Technical Reports Server (NTRS)

    Wallin, Wayne E.; Friefeld, Jerry M.

    1988-01-01

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

  15. High power RF solid state power amplifier system

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  16. Advances in Optimizing Weather Driven Electric Power Systems.

    NASA Astrophysics Data System (ADS)

    Clack, C.; MacDonald, A. E.; Alexander, A.; Dunbar, A. D.; Xie, Y.; Wilczak, J. M.

    2014-12-01

    The importance of weather-driven renewable energies for the United States (and global) energy portfolio is growing. The main perceived problems with weather-driven renewable energies are their intermittent nature, low power density, and high costs. The National Energy with Weather System Simulator (NEWS) is a mathematical optimization tool that allows the construction of weather-driven energy sources that will work in harmony with the needs of the system. For example, it will match the electric load, reduce variability, decrease costs, and abate carbon emissions. One important test run included existing US carbon-free power sources, natural gas power when needed, and a High Voltage Direct Current power transmission network. This study shows that the costs and carbon emissions from an optimally designed national system decrease with geographic size. It shows that with achievable estimates of wind and solar generation costs, that the US could decrease its carbon emissions by up to 80% by the early 2030s, without an increase in electric costs. The key requirement would be a 48 state network of HVDC transmission, creating a national market for electricity not possible in the current AC grid. These results were found without the need for storage. Further, we tested the effect of changing natural gas fuel prices on the optimal configuration of the national electric power system. Another test that was carried out was an extension to global regions. The extension study shows that the same properties found in the US study extend to the most populous regions of the planet. The extra test is a simplified version of the US study, and is where much more research can be carried out. We compare our results to other model results.

  17. Systems definition space based power conversion systems: Executive summary

    NASA Technical Reports Server (NTRS)

    1977-01-01

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

  18. Targeting the neurophysiology of cognitive systems with transcranial alternating current stimulation (tACS)

    PubMed Central

    Fröhlich, Flavio; Sellers, Kristin K.; Cordle, Asa L.

    2015-01-01

    Cognitive impairment represents one of the most debilitating and most difficult symptom to treat of many psychiatric illnesses. Human neurophysiology studies have suggested specific pathologies of cortical network activity correlate with cognitive impairment. However, we lack (1) demonstration of causal relationships between specific network activity patterns and cognitive capabilities and (2) treatment modalities that directly target impaired network dynamics of cognition. Transcranial alternating current stimulation (tACS), a novel non-invasive brain stimulation approach, may provide a crucial tool to tackle these challenges. We here propose that tACS can be used to elucidate the causal role of cortical synchronization in cognition and, eventually, to enhance pathologically weakened synchrony that may underlie cognitive deficits. To accelerate such development of tACS as a treatment for cognitive deficits, we discuss studies on tACS and cognition (all performed in healthy participants) according to the Research Domain Criteria (RDoC) of the National Institute of Mental Health. PMID:25547149

  19. Integrated systems for pulsed-power driven inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Cuneo, M. E.; Slutz, S. A.; Stygar, W. A.; Herrmann, M. C.; Sinars, D. B.; McBride, R. D.; Vesey, R. A.; Sefkow, A. B.; Mazarakis, M. G.; Vandevender, J. P.; Waisman, E. M.; Hansen, D. L.; Owen, A. C.; Jones, J. F.; Romero, J. A.; McKenney, J.

    2011-10-01

    Pulsed power fusion concepts integrate: (i) directly-magnetically-driven fusion targets that absorb large energies (10 MJ), (ii) efficient, rep-rated driver modules, (iii) compact, scalable, integrated driver architectures, (iv) driver-to-target coupling techniques with standoff and driver protection, and (v) long lifetime fusion chambers shielded by vaporizing blankets and thick liquid walls. Large fusion yields (3-30 GJ) and low rep-rates (0.1-1 Hz) may be an attractive path for IFE. Experiments on the ZR facility are validating physics issues for magnetically driven targets. Scientific breakeven (fusion energy = fuel energy) may be possible in the next few years. Plans for system development and integration will be discussed. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  20. Maintenance of photovoltaic power systems, revision 1

    NASA Astrophysics Data System (ADS)

    Hall, M. R.

    1985-06-01

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

  1. High power laser perforating tools and systems

    DOEpatents

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

    2014-04-22

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

  2. Solar-powered hot-water system

    NASA Technical Reports Server (NTRS)

    Collins, E. R.

    1979-01-01

    Hot-water system requires no external power except solar energy. System is completely self-controlling. It includes solar-powered pump, solar-thermally and hydrothermally operated valves, and storage tank filled with open-celled foam, to maintain thermal stratification in stored water.

  3. Automated System Tests High-Power MOSFET's

    NASA Technical Reports Server (NTRS)

    Huston, Steven W.; Wendt, Isabel O.

    1994-01-01

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

  4. The ACS Virgo Cluster Survey. XIV. Analysis of Color-Magnitude Relations in Globular Cluster Systems

    NASA Astrophysics Data System (ADS)

    Mieske, Steffen; Jordán, Andrés; Côté, Patrick; Kissler-Patig, Markus; Peng, Eric W.; Ferrarese, Laura; Blakeslee, John P.; Mei, Simona; Merritt, David; Tonry, John L.; West, Michael J.

    2006-12-01

    We examine the correlation between globular cluster (GC) color and magnitude using HST ACS imaging for a sample of 79 early-type galaxies (-21.7ACS Virgo Cluster Survey. Using the KMM mixture modeling algorithm, we find a highly significant correlation, γz≡d(g-z)/dz=-0.037+/-0.004, between color and magnitude for the subpopulation of blue GCs in the co-added GC color-magnitude diagram of the three brightest Virgo Cluster galaxies (M49, M87, and M60): brighter GCs are redder than their fainter counterparts. For the single GC systems of M87 and M60, we find similar correlations; M49 does not appear to show a significant trend. There is no correlation between (g-z) and Mz for GCs of the red subpopulation. The correlation γg≡d(g-z)/dg for the blue subpopulation is much weaker than d(g-z)/dz. Using Monte Carlo simulations, we attribute this finding to the fact that the blue subpopulation in Mg extends to higher luminosities than does the red subpopulation, which biases the KMM fit results. The correlation between color and Mz thus is a real effect: this conclusion is supported by biweight fits to the same color distributions. We identify two environmental dependencies that influence the derived color-magnitude relation: (1) the slope decreases in significance with decreasing galaxy luminosity; and (2) the slope is stronger for GC populations located at smaller galactocentric distances. We examine several physical mechanisms that might give rise to the observed color-magnitude relation: (1) presence of contaminators; (2) accretion of GCs from low-mass galaxies; (3) stochastic effects; (4) the capture of field stars by individual GCs; and (5) GC self-enrichment. We conclude that self-enrichment and field-star capture, or a combination of these processes, offer the most promising means of explaining our observations. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope

  5. 1996 international conference on power electronics, drives and energy systems for industrial growth: Proceedings. Volume 1

    SciTech Connect

    Murthy, S.S.; Roy, S.; Divan, D.; Doradla, S.R.; Murthy, B.V.

    1995-12-31

    This book contains Volume 1 of the proceedings of the IEEE International Conference on Power Electronics, Drives and Energy Systems for Industrial Growth held January, 1996, in New Delhi. The topics of the papers include resonant and soft switching converters, induction motor drives, solar power generation, control aspects of power generation, PWM and DC/DC converters, field oriented control of AC machines, wind power generation, analysis of electrical machines, topology and control of power electronic converters, switched reluctance and permanent magnet motor drives, active filters and VAR compensation schemes, analysis and design of induction generators/motors, simulation of power electronics converters and drive, brushless and special electrical machines, UPS and battery energy storage systems.

  6. An electrochemical study of corrosion protection by primer-topcoat systems on 4130 steel with ac impedance and dc methods

    NASA Technical Reports Server (NTRS)

    Mendrek, M. J.; Higgins, R. H.; Danford, M. D.

    1988-01-01

    To investigate metal surface corrosion and the breakdown of metal protective coatings, the ac impedance method is applied to six systems of primer coated and primer topcoated 4130 steel. Two primers were used: a zinc-rich epoxy primer and a red lead oxide epoxy primer. The epoxy-polyamine topcoat was used in four of the systems. The EG and G-PARC Model 368 ac impedance measurement system, along with dc measurements with the same system using the polarization resistance method, were used to monitor changing properties of coated 4230 steel disks immersed in 3.5 percent NaCl solutions buffered at pH 5.4 over periods of 40 to 60 days. The corrosion system can be represented by an electronic analog called an equivalent circuit consisting of resistors and capacitors in specific arrangements. This equivalent circuit parallels the impedance behavior of the corrosion system during a frequency scan. Values for the resistors and capacitors, that can be assigned in the equivalent circuit following a least-squares analysis of the data, describe changes that occur on the corroding metal surface and in the protective coatings. Two equivalent circuits have been determined that predict the correct Bode phase and magnitude of the experimental sample at different immersion times. The dc corrosion current density data are related to equivalent circuit element parameters. Methods for determining corrosion rate with ac impedance parameters are verified by the dc method.

  7. Concentrators Enhance Solar Power Systems

    NASA Technical Reports Server (NTRS)

    2013-01-01

    "Right now, solar electric propulsion is being looked at very seriously," says Michael Piszczor, chief of the photovoltaic and power technologies branch at Glen Research Center. The reason, he explains, originates with a unique NASA mission from the late 1990s. In 1998, the Deep Space 1 spacecraft launched from Kennedy Space Center to test a dozen different space technologies, including SCARLET, or the Solar Concentrator Array with Refractive Linear Element Technology. As a solar array that focused sunlight on a smaller solar cell to generate electric power, SCARLET not only powered Deep Space 1 s instruments but also powered its ion engine, which propelled the spacecraft throughout its journey. Deep Space 1 was the first spacecraft powered by a refractive concentrator design like SCARLET, and also utilized multi-junction solar cells, or cells made of multiple layers of different materials. For the duration of its 38-month mission, SCARLET performed flawlessly, even as Deep Space 1 flew by Comet Borrelly and Asteroid Braille. "Everyone remembers the ion engine on Deep Space 1, but they tend to forget that the SCARLET array powered it," says Piszczor. "Not only did both technologies work as designed, but the synergy between the two, solar power and propulsion together, is really the important aspect of this technology demonstration mission. It was the first successful use of solar electric propulsion for primary propulsion." More than a decade later, NASA is keenly interested in using solar electric propulsion (SEP) for future space missions. A key issue is cost, and SEP has the potential to substantially reduce cost compared to conventional chemical propulsion technology. "SEP allows you to use spacecraft that are smaller, lighter, and less costly," says Piszczor. "Even though it might take longer to get somewhere using SEP, if you are willing to trade time for cost and smaller vehicles, it s a good trade." Potentially, SEP could be used on future science missions

  8. Optimized efficiency of all-electric ships by dc hybrid power systems

    NASA Astrophysics Data System (ADS)

    Zahedi, Bijan; Norum, Lars E.; Ludvigsen, Kristine B.

    2014-06-01

    Hybrid power systems with dc distribution are being considered for commercial marine vessels to comply with new stringent environmental regulations, and to achieve higher fuel economy. In this paper, detailed efficiency analysis of a shipboard dc hybrid power system is carried out. An optimization algorithm is proposed to minimize fuel consumption under various loading conditions. The studied system includes diesel engines, synchronous generator-rectifier units, a full-bridge bidirectional converter, and a Li-Ion battery bank as energy storage. In order to evaluate potential fuel saving provided by such a system, an online optimization strategy for fuel consumption is implemented. An Offshore Support Vessel (OSV) is simulated over different operating modes using the online control strategy. The resulted consumed fuel in the simulation is compared to that of a conventional ac power system, and also a dc power system without energy storage. The results show that while the dc system without energy storage provides noticeable fuel saving compared to the conventional ac system, optimal utilization of the energy storage in the dc system results in twice as much fuel saving.

  9. Apparatus for controlling steering power in power steering system

    SciTech Connect

    Hirakushi, S.; Matsubara, H.

    1988-10-04

    This patent describes an apparatus for controlling a steering power in a power steering system which is used in an automobile. The apparatus consists of: a main pump which supplies a first hydraulic coil to the power steering system to operate the same; an oil pressure reaction chamber for controlling the steering power; a subpump of a reduced size smaller than that of the main pump for supplying a second hydraulic oil to the oil pressure reaction chamber to operate the same; a first oil path interconnecting the subpump and oil pressure reaction chamber to each other for flowing the second hydraulic oil through the first oil path; an oil tank; a second oil path branched from the first oil path and connected to the oil tank; a first control valve means disposed in the second oil path for raising the hydraulic pressure of the oil pressure reaction chamber in response to an increase in the running speed of the automobile so as to control the oil pressure reaction chamber to increase the steering power; and a second control valve means connected in parallel relationship with the first control valve means for changing the steering power in response to the hydraulic pressure of the first hydraulic oil supplied from the main pump.

  10. Wearable and Implantable Mechanical Energy Harvesters for Self-Powered Biomedical Systems.

    PubMed

    Hinchet, Ronan; Kim, Sang-Woo

    2015-08-25

    In this issue of ACS Nano, Tang et al. investigate the ability of a triboelectric nanogenerator (TENG) to self-power a low-level laser cure system for osteogenesis by studying the efficiency of a bone remodeling laser treatment that is powered by a skin-patch-like TENG instead of a battery. We outline this field by highlighting the motivations for self-powered biomedical systems and by discussing recent progress in nanogenerators. We note the overlap between biomedical devices and TENGs and their dawning synergy, and we highlight key prospects for future developments. Biomedical systems should be more autonomous. This advance could improve their body integration and fields of action, leading to new medical diagnostics and treatments. However, future self-powered biomedical systems will need to be more flexible, biocompatible, and biodegradable. These advances hold the promise of enabling new smart autonomous biomedical systems and contributing significantly to the Internet of Things. PMID:26280752

  11. Design and application of PV power system for 100w to 10kw

    SciTech Connect

    Matlin, R.W.

    1982-06-01

    Photovoltaic systems are economically viable in remote areas where grid power is not available and where power requirements are modest. PV systems provide power for water pumping, navigation aids, and residential electrification. Water pumping applications are projected to provide the largest market. The world's largest PV pumping unit, a 25Kw centrifugal pump system used to irrigate 80 acres of corn in Nebraska, is shown. Volumetric style ''jack pumps'' have been installed in the Upper Volta, and in Arizona. Remote residential AC power systems at the Hopi reservation, and a navigational aid system in the St. Lawrence Seaway are also demonstrated. Life cycle costing has shown that it is preferable to use deep cycle batteries.

  12. Space power plants and power-consuming industrial systems

    SciTech Connect

    Latyshev, L.; Semashko, N.

    1996-12-31

    An opportunity to create the space power production on the basis of solar, nuclear and fusion energies is analyzed. The priority of solar power production as the most accessible and feasible in comparison with others is emphasized. However, later on, it probably will play an auxiliary role. The possibilities of fusion power production, as a basic one in future, are also considered. It is necessary to create reactors using the fueling cycle with helium-3 (instead of tritium and deuterium, later on). The reaction products--charged particles, mainly--allow one to organize the system of direct fusion energy conversion into electricity. The produced energy is expected not to be transmitted to Earth, but an industry in space is expected to be produced on its basis. The industrial (power and science-consuming) objects located on a whole number of space apparatus will form a single complex with its own basic power plant. The power transmission within the complex will be realized with high power density fluxes of microwave radiation to short distances with their receivers at the objects. The necessary correction of the apparatus positions in the complex will be done with ion and plasma thrusters. The materials present on the Moon, asteroids and on other planets can serve as raw materials for industrial objects. Such an approach will help to improve the ecological state on Earth, to eliminate the necessity in the fast energy consumption growth and to reduce the hazard of global thermal crisis.

  13. 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.

  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. Steady state security assessment in deregulated power systems

    NASA Astrophysics Data System (ADS)

    Manjure, Durgesh Padmakar

    Power system operations are undergoing changes, brought about primarily due to deregulation and subsequent restructuring of the power industry. The primary intention of the introduction of deregulation in power systems was to bring about competition and improved customer focus. The underlying motive was increased economic benefit. Present day power system analysis is much different than what it was earlier, essentially due to the transformation of the power industry from being cost-based to one that is price-based and due to open access of transmission networks to the various market participants. Power is now treated as a commodity and is traded in an open market. The resultant interdependence of the technical criteria and the economic considerations has only accentuated the need for accurate analysis in power systems. The main impetus in security analysis studies is on efficient assessment of the post-contingency status of the system, accuracy being of secondary consideration. In most cases, given the time frame involved, it is not feasible to run a complete AC load flow for determining the post-contingency state of the system. Quite often, it is not warranted as well, as an indication of the state of the system is desired rather than the exact quantification of the various state variables. With the inception of deregulation, transmission networks are subjected to a host of multilateral transactions, which would influence physical system quantities like real power flows, security margins and voltage levels. For efficient asset utilization and maximization of the revenue, more often than not, transmission networks are operated under stressed conditions, close to security limits. Therefore, a quantitative assessment of the extent to which each transaction adversely affects the transmission network is required. This needs to be done accurately as the feasibility of the power transactions and subsequent decisions (execution, curtailment, pricing) would depend upon the

  16. High frequency power distribution system

    NASA Technical Reports Server (NTRS)

    Patel, Mikund R.

    1986-01-01

    The objective of this project was to provide the technology of high frequency, high power transmission lines to the 100 kW power range at 20 kHz frequency. In addition to the necessary design studies, a 150 m long, 600 V, 60 A transmission line was built, tested and delivered for full vacuum tests. The configuration analysis on five alternative configurations resulted in the final selection of the three parallel Litz straps configuration, which gave a virtually concentric design in the electromagnetic sense. Low inductance, low EMI and flexibility in handling are the key features of this configuration. The final design was made after a parametric study to minimize the losses, weight and inductance. The construction of the cable was completed with no major difficulties. The R,L,C parameters measured on the cable agreed well with the calculated values. The corona tests on insulation samples showed a safety factor of 3.

  17. Nuclear power propulsion system for spacecraft

    NASA Astrophysics Data System (ADS)

    Koroteev, A. S.; Oshev, Yu. A.; Popov, S. A.; Karevsky, A. V.; Solodukhin, A. Ye.; Zakharenkov, L. E.; Semenkin, A. V.

    2015-12-01

    The proposed designs of high-power space tugs that utilize solar or nuclear energy to power an electric jet engine are reviewed. The conceptual design of a nuclear power propulsion system (NPPS) is described; its structural diagram, gas circuit, and electric diagram are discussed. The NPPS incorporates a nuclear reactor, a thermal-to-electric energy conversion system, a system for the conversion and distribution of electric energy, and an electric propulsion system. Two criterion parameters were chosen in the considered NPPS design: the temperature of gaseous working medium at the nuclear reactor outlet and the rotor speed of turboalternators. The maintenance of these parameters at a given level guarantees that the needed electric voltage is generated and allows for power mode control. The processes of startup/shutdown and increasing/reducing the power, the principles of distribution of electric energy over loads, and the probable emergencies for the proposed NPPS design are discussed.

  18. Electric Power System Technology Options for Lunar Surface Missions

    NASA Technical Reports Server (NTRS)

    Kerslake, Thomas W.

    2005-01-01

    In 2004, the President announced a 'Vision for Space Exploration' that is bold and forward-thinking, yet practical and responsible. The vision explores answers to longstanding questions of importance to science and society and will develop revolutionary technologies and capabilities for the future, while maintaining good stewardship of taxpayer dollars. One crucial technology area enabling all space exploration is electric power systems. In this paper, the author evaluates surface power technology options in order to identify leading candidate technologies that will accomplish lunar design reference mission three (LDRM-3). LDRM-3 mission consists of multiple, 90-day missions to the lunar South Pole with 4-person crews starting in the year 2020. Top-level power requirements included a nominal 50 kW continuous habitat power over a 5-year lifetime with back-up or redundant emergency power provisions and a nominal 2-kW, 2-person unpressurized rover. To help direct NASA's technology investment strategy, this lunar surface power technology evaluation assessed many figures of merit including: current technology readiness levels (TRLs), potential to advance to TRL 6 by 2014, effectiveness of the technology to meet the mission requirements in the specified time, mass, stowed volume, deployed area, complexity, required special ground facilities, safety, reliability/redundancy, strength of industrial base, applicability to other LDRM-3 elements, extensibility to Mars missions, costs, and risks. For the 50-kW habitat module, dozens of nuclear, radioisotope and solar power technologies were down-selected to a nuclear fission heat source with Brayton, Stirling or thermoelectric power conversion options. Preferred energy storage technologies included lithium-ion battery and Proton Exchange Membrane (PEM) Regenerative Fuel Cells (RFC). Several AC and DC power management and distribution architectures and component technologies were defined consistent with the preferred habitat

  19. Hydrogen turbine power conversion system assessment

    NASA Technical Reports Server (NTRS)

    Wright, D. E.; Lucci, A. D.; Campbell, J.; Lee, J. C.

    1978-01-01

    A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three most promising candidates: (1) Ericsson Cycle, (2) gas turbine, and (3) direct steam injection system for fossil fuel as well as nuclear powerplants. A technical and economic evaluation was performed on the three systems from which the direct injection system (fossil fuel only) was selected for a preliminary conceptual design of an integrated hydrogen-fired power conversion system.

  20. Solar energy thermally powered electrical generating system

    NASA Technical Reports Server (NTRS)

    Owens, William R. (Inventor)

    1989-01-01

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