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1

Investigations of voltage flicker in electric arc furnace power systems  

Microsoft Academic Search

The issues of voltage flicker in electric utility power systems serving arc furnace loads are discussed with various limit curves, manual calculation methods, and field tests in this paper. The interaction of arc furnace power system harmonic filters is discussed to show a correlation between filter tuning and voltage flicker under certain operating conditions. Example systems consisting of multiple furnaces

S. R. Mendis; M. T. Bishop; J. F. Witte

1994-01-01

2

On voltage collapse in electric power systems  

Microsoft Academic Search

Voltage collapses which have a period of slowly decreasing voltage followed by an accelerating collapse in voltage are analyzed based on a center manifold voltage collapse model. The essence of this model is that the system dynamics after bifurcation are captured by the center manifold trajectory. It is a computable model that allows prediction of voltage collapse. Both physical explanations

Hsiao-Dong Chiang; Ian Dobson; R. J. Thomas; J. S. Thorp; L. Fekih-Ahmed

1990-01-01

3

A particle swarm optimization for reactive power and voltage control in electric power systems  

Microsoft Academic Search

This paper presents a particle swarm optimization (PSO) for reactive power and voltage control (RPVC) in electric power systems. RPVC can be formulated as a mixed-integer nonlinear optimization problem (MINLP). The proposed method expands the original PSO to handle a MINLP and determines an RPVC strategy with continuous and discrete control variables such as automatic voltage regulator (AVR) operating values

Yoshikazu Fukuyama; Hirotaka Yoshida

2001-01-01

4

Investigations of voltage flicker in electric arc furnace power systems  

Microsoft Academic Search

Operation of rapidly varying loads such as AC and DC arc furnaces in large industrial power systems will cause voltage flicker on the utility system. System planning will help in determining the available short-circuit duty at the point-of-common-coupling to keep the voltage flicker within acceptable limits. Perceptible flicker limit curves are useful in determining the amount of flicker in a

S. R. Mendis; M. T. Bishop; J. F. Witte

1996-01-01

5

A methodology for the assessment of short duration voltage variations in electric power distribution systems  

Microsoft Academic Search

This paper deals with a new methodology for the assessment of power quality indices in electric power distribution systems. Power quality indices concerning short duration voltage variations, i.e. voltage sags and swells, are particularly introduced taking into account the needs for establishing power quality standards. The paper also presents a new proposal for a measurement protocol, a testing procedure to

N. Kagan; E. L. Ferrari; N. M. Matsuo; S. X. Duarte; J. L. Cavaretti; A. Tenorio; L. R. Souza

2002-01-01

6

DC Voltage Control of the DC Micro-Grid for Super High Quality Electric Power Distribution  

Microsoft Academic Search

``DC Micro-grid'' is a novel power system using dc distribution in order to provide super high quality electric power. The power is distributed through dc distribution line and converted to required ac or dc voltages by converters placed near loads. The load side converters do not need transformers by choosing proper distributed dc voltage (±170V). The dc distribution line is

Hiroaki Kakigano; Yushi Miura; Toshifumi Ise; Ryohei Uchida

2007-01-01

7

Feasibility of an Epidemiological Study of Workers Occupationally Exposed to High Voltage Electric Fields in the Electric Power Industry.  

National Technical Information Service (NTIS)

This feasibility study was conducted for the Electric Power Research Institute to investigate the practicality of an epidemiological study on workers occupationally exposed to high voltage electric fields. Identification of a target population to be studi...

H. M. D. Utidjian

1979-01-01

8

Observations on the geometry of saddle node bifurcation and voltage collapse in electrical power systems  

Microsoft Academic Search

Saddle node bifurcation is a generic instability of parameterized differential equation models. The bifurcation geometry and some implications for the study of voltage collapse in electric power systems is described. The initial direction in state space of dynamic voltage collapse can be calculated from a right eigenvector of a static power system model. The normal vector to the bifurcation set

Ian Dobson

1992-01-01

9

Power Management of Aggregate Electric Water Heater Loads by Voltage Control  

Microsoft Academic Search

This paper discusses a voltage-control strategy for power management of aggregate residential electric water heater (EWH) load. It is shown that by proper control of EWH operating voltage, the aggregate EWH power demand during peak-load hours can be reduced without necessarily sacrificing customers' comfort level.

M. Hashem Nehrir; Runmin Jia; Donald A. Pierre; Donald J. Hammerstrom

2007-01-01

10

Online Monitoring of the Electrical Power Transfer Stability and Voltage Profile Stability Margins in Electric Power Transmission Systems Using Phasor Measurement Units Data Sets  

Microsoft Academic Search

An innovative method to monitor the electric power transfer stability on power transmission paths and the voltage profile stability at the power systems nodes in real time modus is proposed. Based on the laws of electric circuit theory, the transfer operating mode of each relevant transmission line is formulated in an active power-voltage PV characteristic. The relevant transmission line parameters

Yves Nguegan; Albert Claudi; Carsten Strunge

2009-01-01

11

Characteristic Analysis of Temperature Sensor in Dynamic Capacity Increase of High Voltage Electric Power Transmission Lines  

Microsoft Academic Search

Dynamic capacity increase in high voltage electric power transmission line is currently the most economical method for solving electric power transmission bottleneck nowadays. Temperature measurement error of the transmission line will affect the calculated current capacity of the transmission line. In this paper, conductor temperature model was applied to analyze the influence of the measurement error on the maximum current

Yuan Dai; Anqi Song; Wei Wang; Yangchun Cheng; Yongchun Liang; Jianliang Kong; Kai Xiao; Yuning Zhang

2012-01-01

12

Fundamental research into high voltages for further development of electric power distribution systems  

Microsoft Academic Search

In order to guarantee correct electric power distribution, the use of voltages between 765 and 1200 kV was investigated. This fundamental research was conducted in an 1800 kV outdoor test station. After describing the connection and protection devices of the three stage high voltage generating transformer, and the tested equipment which has to withstand humidity, rain, dirt accumulation, snow, ice,

E. Gockenbach; W. Buch; M. Crucius; A. Diessner; H. Luehrmann

1982-01-01

13

Relationship Between Voltage Instability and Multiple Load Flow Solutions in Electric Power Systems  

Microsoft Academic Search

There have been observed several voltage instability phenomena in electric power systems where receiving end voltages oscillate remarkably or get much lower than the nominal values. Those phenomena tend to occur in heavy loaded conditions and seem to be related to the multiple load flow solution problem for the following reasons. It has been confirmed analytically and by simulations that

Y. Tamura; H. Mori; S. Iwamoto

1983-01-01

14

A high voltage electrical power system for low Earth orbit applications  

NASA Technical Reports Server (NTRS)

The results of testing a high voltage electrical power system (EPS) breadboard using high voltage power processing equipment developed at Marshall Space Flight Center and Ni-Cd batteries are discussed. These test results are used to extrapolate to an efficient, reliable, high capacity EPS for near term low Earth orbit, high power applications. EPS efficiencies, figures of merit, and battery reliability with a battery protection and reconditioning circuit are presented.

Lanier, J. R., Jr.; Bush, J. R., Jr.

1984-01-01

15

Investigating the Electric Power Distribution System (EPDS) Bus Voltage in the Presence of Distributed Generation (DG)  

Microsoft Academic Search

This paper investigates the Electric Power Distribution System (EPDS) bus voltage in the presence of Distributed Generation (DG). Distribution Company's (Discos) planner endeavor to develop new planning strategies for their network in order to serve the load growth and provide their customers with a reliable electric supply. In this research work, five different cases including preplanned islanding and grid-connected mode

Hasham Khan; Mohammad Ahmad Choudhry; Tahir Mahmood; Aamir Hanif

2006-01-01

16

A posturing strategy against voltage instabilities in electric power systems  

Microsoft Academic Search

The problem of system collapse or blackout characterized by a local severe voltage depression is generally believed to be associated with inadequate VAR support at key busses. The authors discuss techniques for improving the system security with respect to this index. The effect of adding capacitors are examined. They also present a continuation technique that redistributes the system generation to

A. Tiranuchit; R. J. Thomas

1988-01-01

17

Effect of Induced Alternating Current Voltage on Cathodically Protected Pipelines Paralleling Electric Power Transmission Lines  

Microsoft Academic Search

A field study was conducted to evaluate the effect of induced alternating current (AC) voltage on a cathodically protected pipeline paralleling an electric power transmission line. The study used the instant-off method, with steel probes simulating coating defects. Data regarding probe potentials and currents were compared with the proposed tentative criterion for cathodic protection (CP). Positive proof of the adequacy

F. Kajiyama; Y. Nakamura

1999-01-01

18

A probabilistic nodal loading model and worst case solutions for electric power system voltage stability assessment  

Microsoft Academic Search

In this paper, a new nodal loading model for use in voltage stability assessment of electric power systems is proposed, and the formulation of worst cases based on this model, as well as related numerical methods, are described. In this nodal loading model, called the \\

Yoshihiko Kataoka

2003-01-01

19

Electrical safety analysis in low voltage systems with electronic power converters  

Microsoft Academic Search

The widespread use of the power electronic place the problem of the correct operation of the protection system, in order to guarantee the electrical safety for the person in case of indirect contact downstream a converter. The aim of this paper is to estimate the various shapes of voltage and current waves in case of fault in order to give

M. Brenna; F. Iannone; D. Zaninelli

2005-01-01

20

An Assessment of High-Voltage DC Electrical Power in Aircraft Electrical Systems.  

National Technical Information Service (NTIS)

If the presently installed three-phase ac transmission system on aircraft were replaced by a higher voltage dc (HVDC) transmission using a ground return (the aircraft frame), a reduction in weight of wiring, number of wires, and total power losses equal t...

B. J. Wilson J. P. O'Connor

1970-01-01

21

Bipolar model of the electrical environment of the high-voltage direct current power line  

NASA Astrophysics Data System (ADS)

A numerical model of the ion flow in the vicinity of a high-voltage direct current (HVDC) transmission line operating in corona has been developed. The model solves the system of equations governing electrical potential and positive and negative ion concentrations in bipolar coordinates and includes the effect of horizontal wind. The model predicts the downwind space charge plume and ionic current densities at ground similar to those measured near power lines.

Hoppel, William A.

1985-06-01

22

Effect of induced alternating current voltage on cathodically protected pipelines paralleling electric power transmission lines  

SciTech Connect

A field study was conducted to evaluate the effect of induced alternating current (AC) voltage on a cathodically protected pipeline paralleling an electric power transmission line. The study used the instant-off method, with steel probes simulating coating defects. Data regarding probe potentials and currents were compared with the proposed tentative criterion for cathodic protection (CP). Positive proof of the adequacy of CP was obtained after field testing for 1 year, when probes were removed to ascertain corrosion rates.

Kajiyama, F.; Nakamura, Y. [Tokyo Gas Co., Ltd. (Japan). Fundamental Technology Research Lab.

1999-02-01

23

Effect of Voltage Level on Power System Design for Solar Electric Propulsion Missions  

NASA Technical Reports Server (NTRS)

This paper presents study results quantifying the benefits of higher voltage, electric power system designs for a typical solar electric propulsion spacecraft Earth orbiting mission. A conceptual power system architecture was defined and design points were generated for system voltages of 28-V, 50-V, 120-V, and 300-V using state-of-the-art or advanced technologies. A 300-V 'direct-drive' architecture was also analyzed to assess the benefits of directly powering the electric thruster from the photovoltaic array without up-conversion. Fortran and spreadsheet computational models were exercised to predict the performance and size power system components to meet spacecraft mission requirements. Pertinent space environments, such as electron and proton radiation, were calculated along the spiral trajectory. In addition, a simplified electron current collection model was developed to estimate photovoltaic array losses for the orbital plasma environment and that created by the thruster plume. The secondary benefits of power system mass savings for spacecraft propulsion and attitude control systems were also quantified. Results indicate that considerable spacecraft wet mass savings were achieved by the 300-V and 300-V direct-drive architectures.

Kerslake, Thomas W.

2003-01-01

24

Load insensitive electrical device. [power converters for supplying direct current at one voltage from a source at another voltage  

NASA Technical Reports Server (NTRS)

A class of power converters is described for supplying direct current at one voltage from a source at another voltage. It includes a simple passive circuit arrangement of solid-state switches, inductors, and capacitors by which the output voltage of the converter tends to remain constant in spite of changes in load. The switches are sensitive to the current flowing in the circuit and are employed to permit the charging of capacitance devices in accordance with the load requirements. Because solid-state switches (such as SCR's) may be used with relatively high voltage and because of the inherent efficiency of the invention that permits relatively high switching frequencies, power supplies built in accordance with the invention, together with their associated cabling, can be substantially lighter in weight for a given output power level and efficiency of operation than systems of the prior art.

Schwarz, F. C. (inventor)

1974-01-01

25

Characterization of vertical electric fields and associated voltages induced on a overhead power line from close artificially initiated lightning  

NASA Technical Reports Server (NTRS)

Measurements were characterized of simultaneous vertical electric fields and voltages induced at both ends of a 448 m overhead power line by artificially initiated lightning return strokes. The lightning discharges struck ground about 20 m from one end of the line. The measured line voltages could be grouped into two categories: those in which multiple, similarly shaped, evenly spaced pulses were observed, which are called oscillatory; and those dominated by a principal pulse with subsidiary oscillations of much smaller amplitude, which are called impulsive. Voltage amplitudes range from tens of kilovolts for oscillatory voltages to hundreds of kilovolts for impulsive voltages.

Rubinstein, Marcos; Uman, Martin A.; Thomson, Ewen M.; Medelius, Pedro J.

1991-01-01

26

High voltage-power frequency electrical heating in-situ conversion technology of oil shale  

NASA Astrophysics Data System (ADS)

With the depletion of conventional energy sources,oil shale has got much attention as a new type of energy resource,which is rich and widespread in the world.The conventional utilization of oil shale is mainly focused on resorting to produce shale oil and fuel gas with low extraction efficiency about one in a million due to many shortcomings and limitations.And the in-situ conversion of oil shale,more environmentally friendly,is still in the experimental stage.High voltage-power frequency electrical heating in-situ conversion of oil shale is a new type of in-situ pyrolysis technology.The main equipment includes a high voltage-power frequency generator and interior reactor. The high voltage-power frequency generator can provide a voltage between 220-8000 V which can be adjusted in real time according to the actual situation.Firstly,high voltage is used to breakdown the oil shale to form a dendritic crack between two electrodes providing a conductive channel inside the oil shale rock.And then the power frequency(220V) is used to generate the electric current for heating the internal surface of conductive channel,so that the energy can be transmitted to the surrounding oil shale.When the temperature reaches 350 degree,the oil shale begins to pyrolysis.In addition,the temperature in the conductive channel can be extremely high with high voltage,which makes the internal surface of conductive channel graphitization and improves its heat conduction performance.This technology can successfully make the oil shale pyrolysis, based on a lot of lab experiments,and also produce the combustible shale oil and fuel gas.Compared to other in-situ conversion technology,this method has the following advantages: high speed of heating oil shale,the equipment underground is simple,and easy to operate;it can proceed without the limitation of shale thickness, and can be used especially in the thin oil shale reservoir;the heating channel is parallel to the oil shale layers,which has more effective area for heating and heat transmitting;it has very good adaptability to the formation,the location and depth of the electrodes which can be adjusted according to the specific stratigraphic depth case;A positive(negative) electrode can be connected to multiple negative(positive) electrodes,and the arrangement of the positive and negative electrodes can be evaluated for improving the extraction efficiency.High voltage-power frequency electrical heating in-situ conversion technology is a very promising in-situ pyrolysis method,which could provide a new way of mining oil shale resources.

Sun, Youhong; Yang, Yang; Lopatin, Vladimir; Guo, Wei; Liu, Baochang; Yu, Ping; Gao, Ke; Ma, Yinlong

2014-05-01

27

The Impact of Repetitive Unclamped Inductive Switching on the Electrical Parameters of Low-Voltage Trench Power nMOSFETs  

Microsoft Academic Search

The impact of hot-carrier injection (HCI) due to repetitive unclamped inductive switching (UIS) on the electrical performance of low-voltage trench power n-type MOSFETs (nMOSFETs) is assessed. Trench power nMOSFETs with 20- and 30-V breakdown voltage ratings in TO-220 packages have been fabricated and subjected to over 100 million cycles of repetitive UIS with different avalanche currents IAV at a mounting

Olayiwola Alatise; Ian Kennedy; George Petkos; Keith Heppenstall; Khalid Khan; Jim Parkin; Adrian Koh; Philip Rutter

2010-01-01

28

Generating Electrical Voltage  

NSDL National Science Digital Library

Teachers' Domain presents this interactive lesson designed to help students "learn how a generator converts mechanical energy into electrical energy. Investigate the principle of magnetic induction by moving a conductor through a magnetic field to see how voltage is generated." The lesson is divided into three major sections: How Do Generators Work?, What Factors Influence Voltage Strength?, and What Determines Voltage Polarity? There are plenty of animations to help students visualize the processes at work in electricity generation. On the site, visitors will also find a supplemental background essay, discussion questions, and standards alignment from Teachers' Domain.

2010-10-06

29

Toward a practical performance index for predicting voltage collapse in electric power systems  

Microsoft Academic Search

Voltage collapse is generally caused by either of two types of power system disturbances: load variations; and contingencies. A number of performance indices intended to measure the severity of the voltage collapse problem have been proposed in the literature. However, few of these performance indices can answer questions such as: “can the system withstand another 100 MVar increase on bus

Hsiao-Dong Chiang; R. Jean-Jumeau

1995-01-01

30

Voltage Profile Program for the Kennedy Space Center Electric Power Distribution System.  

National Technical Information Service (NTIS)

The Kennedy Space Center voltage profile program computes voltages at all busses greater than 1 Kv in the network under various conditions of load. The computation is based upon power flow principles and utilizes a Newton-Raphson iterative load flow algor...

1976-01-01

31

Voltage profile program for the Kennedy Space Center electric power distribution system  

NASA Technical Reports Server (NTRS)

The Kennedy Space Center voltage profile program computes voltages at all busses greater than 1 Kv in the network under various conditions of load. The computation is based upon power flow principles and utilizes a Newton-Raphson iterative load flow algorithm. Power flow conditions throughout the network are also provided. The computer program is designed for both steady state and transient operation. In the steady state mode, automatic tap changing of primary distribution transformers is incorporated. Under transient conditions, such as motor starts etc., it is assumed that tap changing is not accomplished so that transformer secondary voltage is allowed to sag.

1976-01-01

32

Environmental justice: a contrary finding for the case of high-voltage electric power transmission lines.  

PubMed

Environmental justice is the consideration of whether minority and/or lower-income residents in a geographic area are likely to have disproportionately higher exposures to environmental toxins than those living elsewhere. Such situations have been identified for a variety of factors, such as air pollution, hazardous waste, water quality, noise, residential crowding, and housing quality. This study investigates the application of this concept to high-voltage electric power transmission lines (HVTL), which some perceive as a health risk because of the magnetic fields they generate, and also as esthetically unpleasing. We mapped all 345 kV and higher voltage HVTL in New York State and extracted and summarized proximate US Census sociodemographic and housing characteristic data into four categories on the basis of distances from HVTL. Contrary to our expectation, people living within 2000 ft from HVTL were more likely to be exposed to magnetic fields, white, of higher income, more educated and home owners, than those living farther away, particularly in urban areas. Possible explanations for these patterns include the desire for the open space created by the rights-of-way, the preference for new homes/subdivisions that are often located near HVTL, and moving closer to HVTL before EMFs were considered a risk. This study suggests that environmental justice may not apply to all environmental risk factors and that one must be cautious in generalizing. In addition, it shows the utility of geographical information system methodology for summarizing information from extremely large populations, often a challenge in epidemiology. PMID:19352413

Wartenberg, Daniel; Greenberg, Michael R; Harris, Gerald

2010-05-01

33

Voltage stability limit of electric power systems with Generator reactive power constraints considered  

Microsoft Academic Search

This paper investigates the smoothness of the transfer limit surface, or the loadability surface, of power systems. The reactive power output constraints of generators are taken into consideration. A new methodology employed for the investigation is based on characterizing each maximum loading point by the state of the generators (PV or PQ). Then the transfer limit surface is investigated through

Yoshihiko Kataoka; Yukio Shinoda

2005-01-01

34

A model-predictive approach to emergency voltage control in electrical power systems  

Microsoft Academic Search

Recent blackouts have shown that traditional local protection against power system collapse is not always sufficient to arrest instabilities. This paper shows that centralized systems can perform better than traditional local protection, as well as outlining how the decision logic of such centralized systems can be implemented. We present a coordinated system protection scheme (SPS) against voltage collapse based on

Mats Larsson

2004-01-01

35

How to reduce radio interference from high-voltage electric power transmission lines  

Microsoft Academic Search

Data from measurements of the radio frequency interference from overhead electric power transmission lines are presented. The quality of radio broadcast and television reception and expansion of reliable reception zones are emphasized.

V. V. Kapitonov; Y. M. Abramson

1978-01-01

36

Medium factors of electrical insulation systems in high temperature superconducting power apparatus with coil structure for equivalent ac withstand voltage test at room temperature  

Microsoft Academic Search

Equivalent insulation test voltage at room temperature of high temperature superconducting (HTS) power apparatus with coil structure for power frequency withstand voltage tests is discussed based on medium factors of insulation weak parts in electrical insulation elements of the HTS power apparatus. Uniform and non-uniform field gaps, triple junction and solid insulator surface are selected as the insulation weak parts,

M. Hara; T. Kurihara; R. Nakano; J. Suehiro

2005-01-01

37

High voltage power transistor development  

NASA Technical Reports Server (NTRS)

Design considerations, fabrication procedures, and methods of evaluation for high-voltage power-transistor development are discussed. Technique improvements such as controlling the electric field at the surface and perserving lifetimes in the collector region which have advanced the state of the art in high-voltage transistors are discussed. These improvements can be applied directly to the development of 1200 volt, 200 ampere transistors.

Hower, P. L.

1981-01-01

38

The irrelevance of electric power system dynamics for the loading margin to voltage collapse and its sensitivities  

NASA Astrophysics Data System (ADS)

The loading margin to a saddle-node or fold bifurcation measures the proximity to voltage collapse blackouts of electric power transmission systems. Sensitivities of the loading margin can be used to select controls to avoid voltage collapse. We analytically justify the use of static models to compute loading margins and their sensitivities and explain how the results apply to underlying dynamic models. The relation between fold bifurcations of the static models and saddle-node bifurcations of the underlying dynamic models is clarified.

Dobson, Ian

39

High voltage power supply  

NASA Technical Reports Server (NTRS)

A high voltage power supply is formed by three discrete circuits energized by a battery to provide a plurality of concurrent output signals floating at a high output voltage on the order of several tens of kilovolts. In the first two circuits, the regulator stages are pulse width modulated and include adjustable ressistances for varying the duty cycles of pulse trains provided to corresponding oscillator stages while the third regulator stage includes an adjustable resistance for varying the amplitude of a steady signal provided to a third oscillator stage. In the first circuit, the oscillator, formed by a constant current drive network and a tuned resonant network included a step up transformer, is coupled to a second step up transformer which, in turn, supplies an amplified sinusoidal signal to a parallel pair of complementary poled rectifying, voltage multiplier stages to generate the high output voltage.

Ruitberg, A. P.; Young, K. M. (inventors)

1985-01-01

40

A sensitivity approach to the sizing of insulated power cables in low and medium voltage electrical power distribution systems  

Microsoft Academic Search

The sizing of insulated power cables for use in electrical power distribution systems is based on definite engineering criteria. Cable or conductor size for a given current loading (ampacity) is the cross-sectional area or size of the current carrying portion of the cable, namely the conductor expressed in AWG (American Wire Gauge) or KCM (Kilocircular mils). The most commonly used

A. K. Hiranandani

1989-01-01

41

Electrical system architecture having high voltage bus  

SciTech Connect

An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

Hoff, Brian Douglas (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL)

2011-03-22

42

Computing an optimum direction in control space to avoid stable node bifurcation and voltage collapse in electric power systems  

Microsoft Academic Search

Given a load power forecast, the sensitivity with respect to controls of a load power margin measuring proximity to voltage collapse is computed. The computation is simple enough to contribute to the practical planning and control of a power system to avoid voltage collapse blackouts. The computation applies to avoiding saddle node bifurcation instability of a general dynamical system

Ian Dobson; Liming Lu

1992-01-01

43

The influence of nonlinear loads on the power quality of the New Zealand low voltage electrical power distribution network  

Microsoft Academic Search

Reducing electrical consumption by eliminating large inefficient loads and introducing smaller more efficient loads, results in large, conventional, linear loads being replaced by smaller modern nonlinear loads. Their electronic front ends make these nonlinear loads more efficient, but they inject harmonics into the power network, bringing total harmonic distortion in New Zealand to near our limit of 5%. To date

Michael S Witherden; Ramesh Rayudu; Rémy Rigo-Mariani

2010-01-01

44

Optimal Daubechies' wavelet bases for detection of voltage sags in electric power distribution and transmission systems  

NASA Astrophysics Data System (ADS)

Wavelet analysis of voltage sag completely depends on the choice of the wavelet basis. For better detection performance via wavelet analysis, the choice of the optimal wavelet basis must be provided within the constraints of the uncertainty principle which restricts arbitrary assignment of time-frequency resolution. In this paper, we describe local properties of the wavelet basis and voltage sag signal in terms of time duration and frequency bandwidth parameters. After comparison of the local properties of the wavelet basis and voltage sag signal, we suggest a set of performance indexes to measure the time-frequency resolution relation between the wavelet basis and the voltage sag signal. This procedure of determining the optimal wavelet basis can be extended to other possible applications of wavelets.

Shin, YongJune; Powers, Edward J.; Grady, William M.; Bhatt, S. C.

1999-10-01

45

Aircraft Electric Secondary Power  

NASA Technical Reports Server (NTRS)

Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

1983-01-01

46

Spacecraft high-voltage power supply construction  

NASA Technical Reports Server (NTRS)

The design techniques, circuit components, fabrication techniques, and past experience used in successful high-voltage power supplies for spacecraft flight systems are described. A discussion of the basic physics of electrical discharges in gases is included and a design rationale for the prevention of electrical discharges is provided. Also included are typical examples of proven spacecraft high-voltage power supplies with typical specifications for design, fabrication, and testing.

Sutton, J. F.; Stern, J. E.

1975-01-01

47

High voltage spacecraft electrical systems design  

NASA Technical Reports Server (NTRS)

Factors which must be considered when designing the best and the most cost-effective high-voltage electrical system for a spacecraft are discussed with particular attention given to the EMC considerations, high-voltage power bus, and harnesses. It is emphasized that the use of serial data buses and lines greatly simplify the harness design and weight. Careful attention to the grounding concept and the EMC requirements is necessary for insuring a 'quiet' spacecraft.

Stone, R. E.

1993-01-01

48

Transmission of DC-Voltage Energy from Magnetohydrodynamic Generators into an Electric Power Network.  

National Technical Information Service (NTIS)

The article discusses the possibilities of changing electrical DC-energy obtained in MHD (magnetohydrodynamic) generators with Hall, Montardy and Faraday connection systems into tri-phase AC energy. It presents diagrams of inverters built from thyristors ...

Z. Badzinski A. Kordus

1969-01-01

49

A three-level DC-DC converter with wide-input voltage operations for ship-electric-power-distribution systems  

Microsoft Academic Search

This paper describes a newly developed three-level dc-dc converter with wide-input voltage operations for ship-electric-power-distribution systems. The proposed converter is designed with zero-voltage-switching (ZVS) techniques. The operational principles, design details and performances of the converter are discussed along with soft-switching characteristics through experimental results. Furthermore, design criteria on the dc-dc converter are focused on the minimization of the circulation current

Byeong-Mun Song; Robert McDowell; Andrew Bushnell; Joel Ennis

2004-01-01

50

A three-level DC-DC converter with wide-input voltage operations for ship-electric-power-distribution systems  

Microsoft Academic Search

This paper describes a newly developed 3-level DC-DC converter with wide-input voltage operations for ship-electric-power-distribution systems. The proposed converter is designed with zero-voltage-switching (ZVS) techniques. The operational principles, designs details and performance of the converter are discussed along with soft-switching characteristics and load transients through experimental waveforms. The converter achieved about 95% efficiency over wide 7kW load conditions.

Byeong-Mun Song; Robert McDowell; Andy Bushnell

2003-01-01

51

Study on Corona Discharge Test under the Power Frequency Voltage of the Severe Non-uniform Electric Field Based on the UV-light Imaging Technology  

Microsoft Academic Search

The study on corona discharge test under the power frequency voltage of the severe non-uniform electric field based on the UV-light imaging technology is conducted. The results illuminate that the corresponding relationship between the characterizing parameter of quantifying the intensity of corona discharge and the comparing parameter is accordant; the characterizing parameter can reflect the basic physical process of gas

Ma Bin; Zhou Wenjun; Wang Tao; Ding Yigong

2006-01-01

52

Study and modeling of noise on the low voltage part of the electrical power distribution network between 30 kHz and 1 MHz  

Microsoft Academic Search

In this paper, an extensive set of noise measurements on the low voltage part of the electrical power distribution network is presented. These measurements were taken in a laboratory environment for several months by means of a spectrum analyzer. Automatic remote measurement software was specifically designed and used for this purpose. The frequencies considered range from 30 kHz to 1

Francisco J. Simois; José I. Acha

2001-01-01

53

Voltage monitor and alarm for power line  

SciTech Connect

A device is described for monitoring the voltage of an electrical power line means, comprising: lamps in circuit with the power line means; a display driver in circuit with the lamps and the power line means and arranged to light one lamp at a time depending on the voltage of the power line means in a predetermined voltage range; oscillator means in circuit with the display driver for generating a fixed frequency signal when the voltage of the power line means is outside the voltage range; an audible sound generator in circuit with the oscillator means and driven thereby to sound an alarm when the oscillator means generates the signal; an auxiliary power supply connected in circuit with the oscillator means; and electronic latching means in circuit with the auxiliary power supply and the oscillator means and arranged to pass a driving current to the oscillator means to keep the same energized and generating the signal, so that the alarm continues to sound even though the voltage of the power line means returns to a magnitude within the predetermined voltage range.

Fathi, S.S.

1986-09-02

54

Efficient design and simulation of an expandable hybrid (wind–photovoltaic) power system with MPPT and inverter input voltage regulation features in compliance with electric grid requirements  

Microsoft Academic Search

In this paper an efficient design along with modeling and simulation of a transformer-less small-scale centralized DC—bus Grid Connected Hybrid (Wind–PV) power system for supplying electric power to a single phase of a three phase low voltage (LV) strong distribution grid are proposed and presented. The main components of the hybrid system are: a PV generator (PVG); and an array

Sotirios B. Skretas; Demetrios P. Papadopoulos

2009-01-01

55

Development of polymer insulators for electrical and high-voltage power lines with the application of radiation-chemical technology  

Microsoft Academic Search

In the field of power engineering the problem of replacing traditional high-voltage porcelain and glass insulators by polymer insulators is being investigated. Polymers are desired which are relatively cheap and easy to process by molding. A copolymer of ethylene and vinyl acetate (EVA) filled aluminium hydroxide satisfys the requirements. In order to increase the heat stability of EVA, radiation-chemical technology

A. V. Kuznetsov; G. N. Aleksandrov; V. S. Ivanov

1993-01-01

56

Power-MOSFET Voltage Regulator  

NASA Technical Reports Server (NTRS)

Ninety-six parallel MOSFET devices with two-stage feedback circuit form a high-current dc voltage regulator that also acts as fully-on solid-state switch when fuel-cell out-put falls below regulated voltage. Ripple voltage is less than 20 mV, transient recovery time is less than 50 ms. Parallel MOSFET's act as high-current dc regulator and switch. Regulator can be used wherever large direct currents must be controlled. Can be applied to inverters, industrial furnaces photovoltaic solar generators, dc motors, and electric autos.

Miller, W. N.; Gray, O. E.

1982-01-01

57

Voltages induced by lightning on electric power distribution lines: Field data and analysis results for the period July 1984-1986  

SciTech Connect

Measurements have been made during 1984 and 1985 at the NASA Kennedy Space Center, Florida using a newly-developed spherical antenna of the time-domain horizontal and vertical electric fields from lightning return strokes. Statistics are presented for the fields of 42 return strokes. The peak horizontal field was about 0.03 of the peak critical field; the horizontal field had a mean risetime and a falltime to half value about 0.3 ..mu..s prior to the peak in the vertical field. Voltage has also been measured at one end of an unenergized power distribution line about 500 m in length and 10 m in height. Tables of measured peak voltages are given. By way of a newly-written computer program, the line voltage has been calculated using the measured fields as inputs. Agreement between the voltage measurement and theory is generally good. The lightning horizontal electric field can significantly contribute to the induced line voltage. The horizontal fields become larger as the earth conductivity decreases. 16 figs., 3 tabs.

Thomson, E.M.

1988-03-01

58

High voltage photovoltaic power converter  

DOEpatents

An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

Haigh, Ronald E. (Arvada, CO); Wojtczuk, Steve (Cambridge, MA); Jacobson, Gerard F. (Livermore, CA); Hagans, Karla G. (Livermore, CA)

2001-01-01

59

Electric Double-Layer Capacitors Applying to Voltage Sag Compensator  

NASA Astrophysics Data System (ADS)

Recently the electric double-layer capacitor (EDLC) which is rapidly charged and discharged and offers long life, maintenance-free, has been developed as a new energy storage element. Therefore, we developed the uninterruptible power supply as voltage sag compensator utilizing EDLC. This paper describes an abstract of EDLC and applying to voltage sag compensation.

Nara, Hidetaka

60

Calculation of geomagnetically induced currents (GIC) in a high-voltage electric power transmission system and estimation of effects of overhead shield wires on GIC modelling  

NASA Astrophysics Data System (ADS)

Geomagnetically induced currents (GIC) flowing in ground-based technological networks, such as electric power transmission grids, are the ground end of the space weather chain originating from the Sun. GIC constitute a possible source of problems to the system. Matrix formulas enabling the calculation of GIC in a power grid have been presented before. In this paper, we summarise the formulas and also express them in an alternative form that includes the (geo)voltages driving GIC during a space weather event more explicitly. An issue usually ignored in GIC modelling is the effect of overhead shield wires protecting a power grid and generally earthed at the towers. By numerical examples, it is shown in this paper that such neglect causes an insignificant error in comparison with other inaccuracies involved in GIC modelling and is thus really acceptable in practice.

Pirjola, Risto

2007-08-01

61

Transient voltage blocking for power converter  

US Patent & Trademark Office Database

A power converter includes a transient voltage protection circuit connected between an input of the power converter and a power stage of the power converter. The transient voltage protection circuit provides a low resistance connection from the input of the power converter to the power stage of the power converter when the input voltage is less than a predetermined threshold, but blocks the input voltage from the power stage when the input voltage is equal to or greater than the predetermined threshold voltage. The power converter may be a boost power converter used in a vehicle to provide power from a main power bus of the vehicle to a subsystem of the vehicle such as an anti-lock brake system.

2014-02-25

62

Intelligent coordinative voltage and reactive power control  

Microsoft Academic Search

A novel local voltage control is proposed where each voltage controller of a generating unit is equipped with additional coordinative voltage controller (CVC), which incorporates intelligent control into the power system. The controllers use artificial neural networks (ANN), trained on a large set of power system states. Optimal power flow (OPF) results serve as the optimal target in the ANN

A. F. Gubina; F. Gubina; R. Golob

2001-01-01

63

Electric power trends  

SciTech Connect

This book provides information about the forces shaping the electric power industry. It provides data on trends in the electric power industry, such as: electric utility ownership; sources of energy; industrial electricity demand; manufacturing energy for heat and power; fossil fuels consumed in electric power generation; electric power transmission; nuclear power plant generators; and residential energy consumption.

Not Available

1989-01-01

64

Flywheel charging module for energy storage used in high-voltage pulsed and multi-mode mobility hybrid electric military vehicle power system  

Microsoft Academic Search

Optimal energy systems is currently designing and manufacturing flywheel-based energy storage systems that are being used to provide pulses of energy for charging high-voltage capacitors in a mobile military system. These systems receive their energy from low-voltage vehicle bus power (28 VDC) and provide output power at over 10,000 VDC without the need for DC-DC voltage conversion electronics. This energy

D. W. Swett; J. G. Blanche

2004-01-01

65

Calculation of electric field distribution at high voltage cable terminations  

Microsoft Academic Search

Crosslinked polyethylene (XLPE) insulated power cables are used for transmission and distribution of electrical power. Such cables are subjected to extensive high voltage testing for performance evaluation and quality control purposes. During such testing, the cable ends have to be prepared carefully to make a proper end termination. Usually deionized water terminations are used for this purpose. Alternatively conductive paint

N. H. Malik; A. A. Al-Arainy; M. I. Qureshi; F. R. Pazheri

2010-01-01

66

Efficient computational methods for a practical performance index and the exact voltage collapse point in electric power systems  

Microsoft Academic Search

The authors develop a new performance index based on the center manifold voltage collapse model as well as a new characteristic equation for computation of the exact collapse point. This index provides a direct relationship between its value and the amount of load demand that the system can further withstand before collapse. This relation makes the performance index readily interpretable

R. Jean-Jumeau; H.-D. Chiang; R. J. Thomas

1992-01-01

67

Simulation of electric arc furnace characteristics for voltage flicker study using MATLAB  

Microsoft Academic Search

Power quality is becoming a more concern of today's power system engineer due to the rapid growth of non-linear loads, such as power electronic control equipments and electric arc furnace (EAF). Harmonics and voltage flicker are the power quality problems which are introduced to the power system as result of non-linear behavior of the electric arc furnace operation. Electric arc

D. C. Bhonsle; R. B. Kelkar

2011-01-01

68

On the reliability of voltage and power as input parameters for the characterization of high power ultrasound applications  

NASA Astrophysics Data System (ADS)

For power levels up to 200 W and sonication times up to 60 s, the electrical power, the voltage and the electrical impedance (more exactly: the ratio of RMS voltage and RMS current) have been measured for a piezocomposite high intensity therapeutic ultrasound (HITU) transducer with integrated matching network, two piezoceramic HITU transducers with external matching networks and for a passive dummy 50 ? load. The electrical power and the voltage were measured during high power application with an inline power meter and an RMS voltage meter, respectively, and the complex electrical impedance was indirectly measured with a current probe, a 100:1 voltage probe and a digital scope. The results clearly show that the input RMS voltage and the input RMS power change unequally during the application. Hence, the indication of only the electrical input power or only the voltage as the input parameter may not be sufficient for reliable characterizations of ultrasound transducers for high power applications in some cases.

Haller, Julian; Wilkens, Volker

2012-11-01

69

Mitigation of Electric Arc Furnace Voltage Flicker Using Static Synchronous Compensator  

Microsoft Academic Search

Based on the improved model of nonlinear time-varying electric arc resistance, the power supply system model of electric arc furnace (EAF) is established in Matlab\\/power system blockset, which is used to investigate voltage flicker problem. A flexible power supply strategy is presented, in which static synchronous compensator (STATCOM) is applied to mitigate the voltage flicker produced by EAF. The instantaneous

Y. F. Wang; J. G. Jiang; L. S. Ge; X. J. Yang

2006-01-01

70

Living and Working Safely Around High-Voltage Power Lines.  

SciTech Connect

High-voltage transmission lines can be just as safe as the electrical wiring in the homes--or just as dangerous. The crucial factor is ourselves: they must learn to behave safely around them. This booklet is a basic safety guide for those who live and work around power lines. It deals primarily with nuisance shocks due to induced voltages, and with potential electric shock hazards from contact with high-voltage lines. References on possible long-term biological effects of transmission lines are shown. In preparing this booklet, the Bonneville Power Administration has drawn on more than 50 years of experience with high-voltage transmission. BPA operates one of the world`s largest networks of long-distance, high-voltage lines. This system has more than 400 substations and about 15,000 miles of transmission lines, almost 4,400 miles of which are operated at 500,000 volts.

United States. Bonneville Power Administration.

2001-06-01

71

Ultralow Voltage Nanoelectronics Powered Directly, and Solely, From a Tree  

Microsoft Academic Search

Complex patterns of electrical potential differences exist across the structure of a tree. We have characterized these voltages, and measured values ranging from a few millivolts to a few hundred millivolts for Bigleaf maple trees. These potential differences provide a unique opportunity to power nanoelectronic circuits directly from a tree. We have designed, constructed, and successfully tested two ICs, powered

Carlton Himes; Eric Carlson; Ryan J. Ricchiuti; Brian P. Otis; Babak A. Parviz

2010-01-01

72

Intense neutron source: high-voltage power supply specifications  

SciTech Connect

This report explains the need for and sets forth the electrical, mechanical and safety specifications for a high-voltage power supply to be used with the intense neutron source. It contains sufficient information for a supplier to bid on such a power supply.

Riedel, A.A.

1980-08-01

73

Developments in Electric Power Transmission  

Microsoft Academic Search

A brief account of some significant events in the history of electric power transmission related by a past-president of the Institute whose name is closely linked with many of those events and who for many years has been actively engaged in the study of high voltage phenomena.

Harris J. Ryan

1934-01-01

74

Fast-Recovery, High-Voltage Power Diode  

NASA Technical Reports Server (NTRS)

New family of fast-recovery high-voltage power diodes compatible with D60T and D7ST transistors developed. Have wide range of applications in spacecraft and aircraft electrical distribution equipment, dc/dc inverters, and ac motor controllers for high-horsepower electric motors operating from 480-volt ac lines. Fast-Recovery 1,200-V Power Diodes use chip of hexagonal geometry to maximize effective silicon area.

Sundberg, G.; Berman, A.; Balodis, V.; Gaugh, C.; Duffin, J.; Karatnicki, H.; Larson, E.

1985-01-01

75

Calibrator for alternating voltage, current, and power  

Microsoft Academic Search

A computer-controlled calibrator capable of delivering ac sinusoidal and distorted waveform voltage, current, and power with an accuracy of several parts per million is described. The reference ac voltage is obtained using digital-to-analog conversion and the reference ac current by applying the reference voltage to a reference ac resistor. The phase relation is obtained digitally. A combination of feedback and

P. N. Miljanic

1989-01-01

76

Performance comparison of electric power flow solutions using PSCAD  

Microsoft Academic Search

This paper presents the analysis of electric power flow solution consists of specified power and voltage input conditions to power network and producing the complete voltage information at all the system busses. From this analysis the parameters of current flow and voltages were obtained. Computation of power flow solution is easy if it does not involve with a large power

Nurul Huda Ishak; Iza Sazanita Isa; Samihah Abdullah; Syafrudin Masri; Faizal Mohamad Twon Tawi

2010-01-01

77

TOPEX electrical power system  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

78

Low power, scalable multichannel high voltage controller  

DOEpatents

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

2008-03-25

79

Low power, scalable multichannel high voltage controller  

DOEpatents

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

2006-03-14

80

An improved voltage control on large-scale power system  

SciTech Connect

To achieve a better voltage-var control in the electric power transmission system, different facilities are used. Generators are equipped with automatic voltage regulators to cope with sudden and random changes voltage caused by natural load fluctuations or failures. Other devices like capacitors, inductors, transformers with on load tap changers are installed on the network. Faced with the evolution of the network and operating conditions, electricity utilities are more and more interested in overall and coherent control systems, automatic or not. These systems are expected to coordinate the actions of local facilities for a better voltage control (more stable and faster reaction) inside different areas of the network in case of greater voltage and var variations. They affords besides a better use of existing reactive resources. Also, installation of new devices can be avoided allowing economy of investment. With this frame of mind, EDF has designed a system called Co-ordinated Secondary Voltage Control (CSVC). It`s an automatic closed loop system with a dynamic of a few minutes. It takes into account the network conditions (topology, loads), the voltage limits and the generator operating constraints. This paper presents recent improvements which allow the CSVC to control the voltage profile and different kinds of reactive means on a large-scale power system. Furthermore, this paper presents solution to spread out investment costs over several years, considering a deployment gradually extended.

Vu, H.; Pruvot, P.; Launay, C.; Harmand, Y. [Electricite de France, Clamart (France). Study and Research Div.] [Electricite de France, Clamart (France). Study and Research Div.

1996-08-01

81

Integration of the Premium Power Supply on Electric Power System  

Microsoft Academic Search

This paper describes an inverter-interfaced distributed generation (DG) system that is interconnected with the electric power system (EPS). This system has two main goals such as to serve the customer with reliable electric power and to improve power quality like harmonics and voltage event. This system is interfaced through the series and the shunt inverters because inverters are effective to

Jin-Woo Park; Il-Yop Chung; Kyoung-Nam Kim; Jong-Hun Lee; Seung-Il Moon; Byung-Moon Han

2005-01-01

82

Voltage scheduling for low power/energy  

NASA Astrophysics Data System (ADS)

Power considerations have become an increasingly dominant factor in the design of both portable and desk-top systems. An effective way to reduce power consumption is to lower the supply voltage since voltage is quadratically related to power. This dissertation considers the problem of lowering the supply voltage at (i) the system level and at (ii) the behavioral level. At the system level, the voltage of the variable voltage processor is dynamically changed with the work load. Processors with limited sized buffers as well as those with very large buffers are considered. Given the task arrival times, deadline times, execution times, periods and switching activities, task scheduling algorithms that minimize energy or peak power are developed for the processors equipped with very large buffers. A relation between the operating voltages of the tasks for minimum energy/power is determined using the Lagrange multiplier method, and an iterative algorithm that utilizes this relation is developed. Experimental results show that the voltage assignment obtained by the proposed algorithm is very close (0.1% error) to that of the optimal energy assignment and the optimal peak power (1% error) assignment. Next, on-line and off-fine minimum energy task scheduling algorithms are developed for processors with limited sized buffers. These algorithms have polynomial time complexity and present optimal (off-line) and close-to-optimal (on-line) solutions. A procedure to calculate the minimum buffer size given information about the size of the task (maximum, minimum), execution time (best case, worst case) and deadlines is also presented. At the behavioral level, resources operating at multiple voltages are used to minimize power while maintaining the throughput. Such a scheme has the advantage of allowing modules on the critical paths to be assigned to the highest voltage levels (thus meeting the required timing constraints) while allowing modules on non-critical paths to be assigned to lower voltage levels (thus reducing the power consumption). A polynomial time resource and latency constrained scheduling algorithm is developed to distribute the available slack among the nodes such that power consumption is minimum. The algorithm is iterative and utilizes the slack based on the Lagrange multiplier method.

Manzak, Ali

2001-07-01

83

Calculation of geomagnetically induced currents (GIC) in a high-voltage electric power transmission system and estimation of effects of overhead shield wires on GIC modelling  

Microsoft Academic Search

Geomagnetically induced currents (GIC) flowing in ground-based technological networks, such as electric power transmission grids, are the ground end of the space weather chain originating from the Sun. GIC constitute a possible source of problems to the system. Matrix formulas enabling the calculation of GIC in a power grid have been presented before. In this paper, we summarise the formulas

Risto Pirjola

2007-01-01

84

Visualization of an electric power transmission system  

Microsoft Academic Search

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

P. M. Mahadev; R. D. Christie

1994-01-01

85

Powering the electric car  

Microsoft Academic Search

The electric car may represent major new opportunities for America and its electric utilities. Widespread use of electric cars can reduce consumption of both imported and domestic oil, substituting abundant American fuels such as coal and nuclear power. Air and noise pollution can be reduced since emissions from a single power plant are easier to control than those from thousands

G. O. Murray; G. J. Ostrowski

1981-01-01

86

A new SVC control strategy for voltage flicker mitigation and integrated compensation to electric arc furnace  

Microsoft Academic Search

In order to mitigate these harms such as voltage fluctuation and flicker, three-phase imbalance and low power factor, which are caused by impact loads like electric arc furnaces, this paper proposes a new SVC control strategy for voltage flicker mitigation and integrated compensation to impact loads. Taking into account the impact of the active power component of impact loads on

Xu Sheng; Zhao Jian-feng; Tang Guo-qing

2008-01-01

87

High voltage distribution and grounding in high power spacecraft  

NASA Technical Reports Server (NTRS)

Many space missions proposed for the time period from 1985 to 2000 will require large spacecraft to support the onboard loads. In some cases, large electrical power systems will be needed to supply the electrical/electronic equipment loads. These electronic systems will be used for communications, radar, and experimental equipment for aid to earth's overcrowded communication systems, exploration of new energy resources, space exploration, and eventually to supplement terrestrial electric power utilities. For the near term (1985-1990), some of these systems have power levels to 50 kW. The long-term programs, 1990 to post-2000, could possibly have demands in the order of multimegawatts. The problems which have to be solved to construct the required high-voltage power supply systems are considered. Data and conceptual designs generated are found to indicate that grounding and bonding for high power systems can be accomplished in spacecraft by using either manual or automatic joining of the structural members.

Dunbar, W. G.

1982-01-01

88

Advanced electric propulsion system concept for electric vehicles. Addendum 1. Voltage considerations  

SciTech Connect

Seventeen electric vehicle propulsion systems were originally studied to select two designs that best met cost and performance goals. Both systems have now been examined to assess the effect of battery pack voltage on system performance and cost. A voltage range of 54 to 540 V was considered for a typical battery pack capacity of 24 kW-hr. The highest battery specific energy (W-hr/kg) and the lowest cost ($/kW-hr) were obtained at the minimum voltage level. The flywheel system traction motor is a dc, mechanically commutated machine with shunt field control, and due to the flywheel the traction motor and the battery are not subject to extreme peaks of power demand. Design changes in the battery pack voltage simply result in compensating changes in the motor configuration. The basic system uses a permanent-magnet motor with electronic commutation supplied by an ac power control unit. In this system the traction motor and power control unit must handle the peak power needed for acceleration. The traction motor can be designed to operate at specific battery voltages within a broad range, with little effect on motor efficiency, weight, or cost. The power control unit characteristics are effected by battery voltage, and the lowest voltages give the lowest efficiency, highest weight, and highest cost. In both systems, battery costs were the major factor in system voltage selection, and a battery pack with the minimum voltage of 54 V produced the lowest life-cycle cost. The minimum life-cycle cost for the basic system with lead-acid batteries was $0.057/km and for the flywheel system was $0.037/km.

Raynard, A.E.; Forbes, F.E.

1980-08-01

89

FBG based intelligent sensors and structure for electrical power system  

Microsoft Academic Search

Fiber Bragg grating (FBG) sensors are of particular interest for applications in the high voltage environments of electric power industry. The study on the parameter examination and health monitor of the electric power apparatus has great social significance and economic benefits. In this paper, the electric field or voltage sensor is constructed by using the electrostriction material PZT combined with

Yuan Yao; Benshun Yi; Jinsheng Xiao; Zhaohui Li

2007-01-01

90

Power-maximizing electrical energy generation system  

US Patent & Trademark Office Database

An electrical energy generation system comprising: a plurality of photovoltaic generators connected in parallel and connected to a common load via respective DC voltage converters; and a regulator configured to vary the transconductances of said respective voltage converters to maximize the power generated by said current generators; wherein: said generators are also connected to a common input of an additional voltage converter the output of which is connected to said common load; and said regulator is also configured to vary the transconductance of said additional voltage converter to maximize the power generated by said current generators.

2010-08-03

91

Power system's security improvement through ANN-based decentralized secondary voltage control  

Microsoft Academic Search

In the paper, issues of electrical power system (EPS) security are investigated. The EPS equipped with a decentralized modular secondary voltage and reactive power control based on artificial neural networks (ANNs) is presented. Each generator is equipped with an automatic secondary voltage controller with ANNs that requires only local measurements for its operation. The ANNs were trained on optimal power

A. GUBINA R. GOLOB; R. Golob

2000-01-01

92

OPTIMIZED PLACEMENT OF VOLTAGE MEASUREMENT DEVICES FOR DETERMINING LOCATION OF SINGLE LINE-TO-GROUND FAULTS ON OVERHEAD ELECTRIC POWER DISTRIBUTION FEEDERS  

Microsoft Academic Search

Solving the fault location problem on electric power distribution networks requires careful selection of the placement strategy for the data acquisition and signal processing instrumentation on the feeder, as well as the computational algorithms that use these data to pinpoint the actual location or an area that contains the location of the fault. This work presents a mathematical model for

RODRIGO A. F. PEREIRA; LUIS G. W. DA SILVA; MLADEN KEZUNOVIC; JOSÉ R. S. MANTOVANI

93

Monitoring of high voltage power transformer using direct optical partial discharge detection technique  

Microsoft Academic Search

In electrical power systems, high voltage power transformers are used to transfer the power from one substation to another.\\u000a The insulation of the high voltage power transformers are gradually deteriorated due to electrical, chemical and mechanical\\u000a stresses caused by the partial discharges (PDs). It is well established from several studies that PDs are the major source\\u000a of insulation failure in

S. Karmakar; N. K. Roy; P. Kumbhakar

2009-01-01

94

High voltage bus and auxiliary heater control system for an electric or hybrid vehicle  

DOEpatents

A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

Murty, Balarama Vempaty (West Bloomfield, MI)

2000-01-01

95

Advanced electric power systems  

Microsoft Academic Search

An identification and preliminary evaluation was made of alternative advanced electric power systems which have been suggested for possible future use by the American electric utility industry. The motivation for interest in advanced power systems stems primarily from the rapidly rising costs of clean fossil fuels, especially conventional fuel oil, and uncertainties of fuel supply. Four basic energy sources have

Albert J. Giramonti; Robert D. Lessard

1975-01-01

96

On-Chip Voltage Regulator Protecting Against Power Analysis Attacks  

Microsoft Academic Search

The on-chip voltage regulator proposed in this paper has been specifically developed for smart cards. Its purpose is to protect the supplied system against power analysis attacks. It allows to generate the internal power supply voltage from the external power supply voltage provided by card readers, while ensuring the uncorrelation between the external power supply current and the internal power

Vincent Telandro; E. Kussener; A. Malherbe; H. Barthelemy

2006-01-01

97

Bi-directional power control system for voltage converter  

DOEpatents

A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals. 10 figs.

Garrigan, N.R.; King, R.D.; Schwartz, J.E.

1999-05-11

98

Bi-directional power control system for voltage converter  

DOEpatents

A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals.

Garrigan, Neil Richard (Niskayuna, NY); King, Robert Dean (Schenectady, NY); Schwartz, James Edward (Slingerlands, NY)

1999-01-01

99

High voltage, high power nested high voltage accelerator  

Microsoft Academic Search

The nested high-voltage generator (NHVG) is a new type of accelerator based on the principle of the Faraday cage. It consists of a number of individual high-voltage sections which are placed inside of the adjacent accelerator section, or nested one inside the other. Electronics internal to each of the NHVG states sets the voltage between the inner and outer Faraday

R. J. Adler; R. J. Richter-Sand

1991-01-01

100

Electric power annual 1993  

SciTech Connect

This report presents a summary of electric power industry statistics at national, regional, and state levels: generating capability and additions, net generation, fossil-fuel statistics, retail sales and revenue, finanical statistics, environmental statistics, power transactions, demand side management, nonutility power producers. Purpose is to provide industry decisionmakers, government policymakers, analysts, and the public with historical data that may be used in understanding US electricity markets.

Not Available

1994-12-08

101

Contract networks for electric power transmission  

Microsoft Academic Search

A contract network extends the concept of a contract path to address the problem of loop flow and congestion in electric power transmission systems. A contract network option provides an internally consistent framework for assigning long-term capacity rights to a complicated electric transmission network. The contract network respects the special conditions induced by Kirchoff's Laws; accommodates thermal, voltage, and contingency

William W. Hogan

1992-01-01

102

Wavelet-based dynamic voltage restorer for power quality improvement  

Microsoft Academic Search

This paper presents a novel method for power quality improvement employing wavelet analysis. A wavelet filter bank is used to detect and classify various disturbances experienced by the voltage on the load side. A dynamic voltage restorer is used to compensate the voltage under disturbance conditions and maintain the rated load voltage. The input and the output voltages of the

S. A. Saleh; M. A. Rahman

2004-01-01

103

Power quality issues with adjustable frequency drives -- Coping with power loss and voltage transient occurrences  

SciTech Connect

The power quality issue is not new to consumers of electrical power. From individual home owners to large industrial complexes, power quality problems can cause eyebrows to raise or bring industrial giants to their knees. Power quality comes in many forms. It can appear in the form of a voltage source which decreases to a small fraction of its normal strength or as a voltage transient, briefly far exceeding its normal value, ready to break down electrical insulation. It can appear as an oscillating voltage or a traveling voltage wave beating against barriers designed as added protection. Defining a single set of rules to control the characteristics of power quality is difficult, since its impact on electrical equipment changes as the characteristics of equipment change. A key to understanding how to cope with power quality issues begins with understanding the nature of electrical products. The nature of any product is defined by how its components are selected and how the designers apply those components. Reviewing design criteria, component selection and product characteristics can provide this basis of understanding.

Murphy, H.G. (Allen-Bradley Co., Mequon, WI (United States))

1993-07-01

104

Pulsed generation of an electrical voltage at the thermovoltaic effect in SmS  

NASA Astrophysics Data System (ADS)

The thermovoltaic effect in SmS is measured at elevated frequencies near 1000 Hz. Pulsed generation of an electrical voltage at this effect is discovered and explained. The maximal value of the generated voltage and the power of the generated signal are measured to be 6.3 V and about 1 W, respectively. These values are attained at about 130°C.

Kaminskii, V. V.; Didik, V. A.; Kazanin, M. M.; Solov'ev, S. M.

2014-05-01

105

Advanced commercial power system protection practices applied to naval medium voltage power systems  

Microsoft Academic Search

In the U.S. navy's transition to an all-electric ship, system designers must take great care to ensure that critical design choices provide highly reliable and safe power system operation and protection during all mission scenarios. Transitioning from low voltage (450 VAC) radial configurations to medium voltage (13.8 kVAC) multi-source systems requires new naval protection schemes. This paper specifically analyzes methods

David Whitehead; Nomann Fischer

2005-01-01

106

A novel power converter of high voltage switched reluctance drive  

Microsoft Academic Search

Due to the lack of withstand voltage of power electronic devices, and the voltage equalization among devices is hard to achieve when cascading the devices directly, the development of high-voltage switched reluctance drive has been blocked. Therefore, this paper proposes a novel high-voltage switched reluctance drive power converter structured by low-voltage power electronic devices. It introduces the composition and principles

Runquan Meng; Yi Yang

2011-01-01

107

Generator Voltage Building-up Field Test for 500kV Transformer Energization for Black-start Power System  

NASA Astrophysics Data System (ADS)

Considering the risk of blackout, Kyushu electric power company has studied about power system restoration at blackout start. Power system at blackout start is so small that over voltage which does not rise in normal power system is able to rise, because of transient phenomena and saturation of transformer which are caused by voltage application. Power system transformers should be applied its voltage as low as possible, ideally from zero, to prevent over-voltage problem. This paper reports field test results of voltage application by a voltage building-up procedure to a 500kV-1000MVA power system transformer through a transmission line.

Izena, Atsushi; Kihara, Hidemi; Shimojo, Toshikazu; Hirayama, Kaiichirou; Furukawa, Nobuhiko

108

Voltage collapse precipitated by the immediate change in stability when generator reactive power limits are encountered  

Microsoft Academic Search

When a generator of a heavily loaded electric power system reaches a reactive power limit, the system can become immediately unstable and a dynamic voltage collapse leading to blackout may follow. The statics and dynamics of this mechanism for voltage collapse are studied by example and by the generic theory of saddle node and transcritical bifurcations. It is shown that

I. Dobson; L. Lu

1992-01-01

109

Transient Electrical Voltages Within ITER Poloidal Field Coils  

Microsoft Academic Search

High-voltage insulation co-ordination of the coil system is essential for reliable operation of ITER. Transient electrical excitations occur on the terminals of superconducting coils, for example in case of a fast discharge of the coils and if a failure occurs within the components of the electrical circuit. Transient voltage on the coil terminals may lead to non-linear voltage distribution and

Alexander Winkler; Walter H. Fietz; Stefan Fink; Mathias Noe

2012-01-01

110

Power and energy measurements of transient electric discharge.  

PubMed

A simple and inexpensive calculating device for electrical power and energy of transient electric discharges is described. The calculation is made by multiplication of the voltage and current of the discharge by use of wideband integrated circuits. PMID:18699273

Kono, M; Iinuma, K; Kumagai, S

1978-08-01

111

Radio-frequency powered glow discharge device and method with high voltage interface  

SciTech Connect

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

Duckworth, Douglas C. (Knoxville, TN); Marcus, R. Kenneth (Clemson, SC); Donohue, David L. (Vienna, AT); Lewis, Trousdale A. (Oak Ridge, TN)

1994-01-01

112

Radio-frequency powered glow discharge device and method with high voltage interface  

DOEpatents

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

1994-06-28

113

Electric power monthly  

SciTech Connect

The Energy Information Administration (EIA) prepares the Electric Power Monthly (EPM) for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. This publication provides monthly statistics for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. The EIA publishes statistics in the EPM on net generation by energy source, consumption, stocks, quantity, quality, and cost of fossil fuels; and capability of new generating units by company and plant. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead.

NONE

1995-08-01

114

Electric power source device  

SciTech Connect

An electric power source device is described for a motor vehicle having an ignition switch having an off position, comprising: a casing; a battery with electrolyte; a source of electricity; the battery and the source of electricity being included by the casing; means for conditioning the electrolyte of the battery in such a manner as to prevent a drop in capacity of the battery which might otherwise be caused by ambient temperature where the battery is disposed; connecting means for connecting the source of electricity to the battery to charge the battery, the connecting means including a change-over switch means having a charging mode position for connecting the source of electricity to the battery to charge the battery; and controlling means for controlling the change-over switch means in such a manner for disconnecting the source of electricity from the battery when the ignition switch is turned on.

Nakamura, M.; Takagi, Y.; Urakawa, H.

1987-03-17

115

Advanced electric propulsion system concept for electric vehicles. Addendum 1: Voltage considerations  

NASA Technical Reports Server (NTRS)

The two electric vehicle propulsion systems that best met cost and performance goals were examined to assess the effect of battery pack voltage on system performance and cost. A voltage range of 54 to 540 V was considered for a typical battery pack capacity of 24 k W-hr. The highest battery specific energy (W-hr/kg) and the lowest cost ($/kW-hr) were obtained at the minimum voltage level. The flywheel system traction motor is a dc, mechanically commutated with shunt field control, and due to the flywheel the traction motor and the battery are not subject to extreme peaks of power demand. The basic system uses a permanent-magnet motor with electronic commutation supplied by an ac power control unit. In both systems battery cost were the major factor in system voltage selection, and a battery pack with the minimum voltage of 54 V produced the lowest life-cycle cost. The minimum life-cycle cost for the basic system with lead-acid batteries was $0.057/km and for the flywheel system was $0.037/km.

Raynard, A. E.; Forbes, F. E.

1980-01-01

116

Electric power monthly, June 1988  

SciTech Connect

Total net generation by electric utilities in the United States for the month of June 1988 was 232,183 gigawatthours, 3 percent higher than the amount reported a year ago. Although temperatures (measured by cooling degree days) for June 1988 were 9 percent warmer than normal, they were 3 percent cooler than for June 1987. A large portion of that higher demand for electricity was met by nuclear-powered generation. Net generation from nuclear power during June 1988 (44,079 gigawatthours) was only 1 percent below the record set in January of this year, and 21 percent above that reported in June 1987 (36,560 gigawatthours). The only energy source other than nuclear that reported higher levels of net generation during June 1988 was coal, up 2 percent over the same period last year. Warmer-than-normal temperatures did, however, have an affect on various parts of the country. For example, on Wednesday, June 22, 1988, unseasonably high temperatures forced the Pennsylvania, New Jersey, and Maryland Interconnection (PJM) into a system-wide 5-percent voltage reduction for 2 hours. Contributing to that reduction in voltage was the shutdown of the Three Mile Island, Unit 1, for refueling and the closing of the Peach Bottom Units 2 and 3 by the Nuclear Regulatory Commission. Three Mile Island, Unit 1, normally provides the PJM system with about 800 megawatts while the two Peach Bottom units, combined, provide approximately 2100 megawatts. 10 refs., 1 fig., 27 tabs.

Not Available

1988-09-15

117

Electric Power Annual  

EIA Publications

Presents 12 years (2001 - 2012) of national-level data on electricity generating capacity, electricity generation and useful thermal output, fuel receipts, consumption, and emissions. This year's Electric Power Annual has expanded to include several new table series. These include several new annual breakouts of renewable biomass energy sources including wood/wood waste, landfill gas, and biogenic municipal solid waste in Chapter 5 (Consumption of Fossil Fuels); state details of emissions from energy consumption at conventional power plants and combined-heat-and-power plants (Table 9.5); and monthly capacity factors for the past three years and annual capacity factors back to 2008 (Tables 4.8.A. and 4.8.B.)

Orhan Yildiz

2013-12-12

118

Process effects on high voltage electrical assembly performance. Final report  

Microsoft Academic Search

Manufacturing processes and package configurations that affect the operation of some high voltage electrical assemblies have been evaluated. High voltage breakdown, adhesion problems, and encapsulated component and solder joint breakage have been relieved by improvements in residue analysis, cleaning and coating techniques, and stress relief coatings. A quantitative comparison of encapsulated lead stress relief systems has been completed to determine

Cummings

1978-01-01

119

Telecommunications: Electrical Characteristics of Balanced Voltage Digital Interface Circuits.  

National Technical Information Service (NTIS)

The standard specifies the electrical characteristics of balanced voltage digital interface circuits normally implemented in integrated circuit technology that are to be employed for the interchange of serial binary data, timing, and control signals betwe...

1980-01-01

120

Federal electric power  

SciTech Connect

Western Area Power Administration in the Department of Energy markets electric power generated by federal hydroelectric dams in 15 central and western states. Western is planning to construct the Craig/Bonanza transmission line and the controversy involves the questioning of Western's role in the project by an investor-owned utility. GAO found no legal basis to question Western's general authority to construct this project.

Not Available

1989-01-01

121

Analysis on DFIG Wind Power System Low-Voltage Ridethrough  

Microsoft Academic Search

Due to the double fed induction generatorpsilas (DFIG) advantage of controlling active and reactive power independently and partial power converter, DFIG is becoming a popular type of wind power generation system. Nowadays, the grid code demands that the wind power generator possesses the ability of riding through the grid voltage sags, only when the grid voltage drops below the specific

Yulong Wang; Jianlin Li; Shuju Hu; Honghua Xu

2009-01-01

122

A high voltage power supply for the AE-C and D low energy electron experiment  

NASA Technical Reports Server (NTRS)

A description is given of the electrical and mechanical design and operation of high voltage power supplies for space flight use. The supply was used to generate the spiraltron high voltage for low energy electron experiment on AE-C and D. Two versions of the supply were designed and built; one design is referred to as the low power version (AE-C) and the other as the high power version (AE-D). Performance is discussed under all operating conditions.

Gillis, J. A.

1974-01-01

123

Compressing Electrical Power Grids  

Microsoft Academic Search

In this paper we apply the Singular Value Decomposition (SVD) analysis to examining the coupling structure of an electrical power grid in order to highlight opportunities for reducing the network traffic, by identifying what are the salient data that need to be communicated between parts of the infrastructure to apply a control action. Our main finding is that typical grid

Zhifang Wang; Anna Scaglione; Robert J. Thomas

2010-01-01

124

Battery powered electric buses  

Microsoft Academic Search

The paper describes the current status of battery powered electric buses and reports on the results of a five year demonstration project in Düsseldorf. While currently overall costs of battery buses are twenty five per cent higher than for conventional diesel buses, the project has demonstrated the high reliability and technical feasibility of such operations. Developments in technology are expected

H. Gerndt; R. Stellmacher

1989-01-01

125

Improvement of output voltage capability of a two stage direct power converter under unbalanced input voltages  

Microsoft Academic Search

Direct power converters (DPC), which has no energy storage, the converter output voltage capability is affected when the input voltage is unbalanced. This paper proposes the utilization of the clamp capacitor, which is normally needed to protect a DPC, to extend the operating range of a two stage DPC during unbalanced supply, preserving its theoretical output voltage capability. A comprehensive

Thiwanka Wijekoon; Christian Klumpner; P. Wheeler

2005-01-01

126

A particle swarm optimization for reactive power and voltage control considering voltage security assessment  

Microsoft Academic Search

This paper presents a particle swarm optimization (PSO) for reactive power and voltage control (volt\\/VAr control: VVC) considering voltage security assessment (VSA). VVC can be formulated as a mixed-integer nonlinear optimization problem (MINLP). The proposed method expands the original PSO to handle a MINLP and determines an online VVC strategy with continuous and discrete control variables such as automatic voltage

Hirotaka Yoshida; Kenichi Kawata; Yoshikazu Fukuyama; Shinichi Takayama; Yosuke Nakanishi

2000-01-01

127

A novel series connected batteries state of high voltage safety monitor system for electric vehicle application.  

PubMed

Batteries, as the main or assistant power source of EV (Electric Vehicle), are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS), the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application. PMID:24194677

Jiaxi, Qiang; Lin, Yang; Jianhui, He; Qisheng, Zhou

2013-01-01

128

Improvement of diagnostic techniques and electrical circuit in azo dye degradation by high voltage electrical discharge  

Microsoft Academic Search

Fast electrical diagnostics and improvement of electrical circuits for methyl orange (MO) degradation by high voltage pulsed electrical discharge were investigated. To eliminate electromagnetic radiation, several effective methods were employed. RG 218 coaxial cable was substituted for the common transmission lines to transmit high voltage pulses, and multi-lines in parallel were earthed to avoid electromagnetic interference and, additionally, to reduce

Yongjun Shen; Lecheng Lei; Xingwang Zhang; Minghua Zhou; Yi Zhang

2008-01-01

129

Reducing electric power transmission losses  

Microsoft Academic Search

The reduction of transmission-related power losses in electric grids has become increasingly important in every phase of power systems concerned with conservation of fuel and power resources. The most effective approaches to the matter of electric power loss reduction in power transmission lines are discussed. These methods include reactive power compensation, both on loads and system substations, optimization of grid

A. I. Kulchitskii; S. P. Elagina

1982-01-01

130

A new advanced over excitation limiter for enhancing the voltage stability of power systems  

Microsoft Academic Search

Mitsubishi Electric has developed an advanced over excitation limiter (OEL) that not only protects the generator field winding from overheating, but also allows the generator to supply reactive power up to its maximum limitation. This in turn allows for the enhancement of voltage stability of a power system by allowing the full range of reactive power supplying ability of a

Masaru Shimomura; Yuou Xia; Masaru Wakabayashi; John Paserba

2001-01-01

131

Direct fault location in electrical power systems  

SciTech Connect

This thesis presents an alternative to existing fault locating procedures in electrical power systems. The theoretical approach is based on the adjoint network concept, utilizing Tellegen's theorem. This theorem may be applied in the frequency or time domain. Also the current and voltage measurements taken from different networks, with the same topology and branch numbering, may be taken at different times. The aim is to apply the theorem in locating balanced or unbalanced faults in electric power transmission and distribution systems, using terminal voltage and current measurements combined with a minimum knowledge of the internal voltages and currents of the network. A detailed description of the theoretical basis for the proposed approach is presented along with numerical examples illustrating the potential application of the proposed technique.

Thomas, B.J.

1985-01-01

132

Liberation of minerals by high-voltage electrical pulses  

Microsoft Academic Search

Liberation of minerals by the high voltage electrical pulses is a new specific liberation technology, capable of producing of the high percentage of the monomineral particles at disintegration of mineral aggregates. The specific liberation effect at the disintegration of rock by electrical pulses is due to the locality of the explosive plasma streamers at the interface of mineral components of

U Andres; J Jirestig; I Timoshkin

1999-01-01

133

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.

134

Effects of High-Voltage Switching on the EPRI-NBS (Electric Power Research Institute-National Bureau of Standards) Coupling Capacitor Voltage Transformer (CCVT) Calibration System Standard Divider.  

National Technical Information Service (NTIS)

The report presents the results of tests of the effects of high-voltage switching on the EPRI-NBS CCVT calibration system's capacitive standard divider, completing an investigation stemming from the results of three calibrations at a Gulf States Utilities...

D. L. Hillhouse

1983-01-01

135

Voltage Regulator for Battery Power Source.  

National Technical Information Service (NTIS)

A bipolar transistor in series with the battery as the control element also in series with a zener diode and a resistor is used to maintain a predetermined voltage until the battery voltage decays to very nearly the predetermined voltage. A field effect t...

J. M. Black

1979-01-01

136

Review of dynamic voltage restorer for power quality Improvement  

Microsoft Academic Search

Power quality has always been important for customers, but with increasing applications of electronic loads and controllers sensitive to the power quality, the subject has attracted renewed interest in recent times. Power quality encompasses several aspects: harmonics, over voltage, flicker voltage sags and swells, interruptions etc., lasting only a few cycles can cause significant damage for a manufacturing process and

J. Praveen; B. P. Muni; S. Venkateshwarlu; H. V. Makthal

2004-01-01

137

Programmable high voltage power supply with regulation confined to the high voltage section  

NASA Technical Reports Server (NTRS)

A high voltage power supply in a dc-dc converter configuration includes a pre-regulator which filters and regulates the dc input and drives an oscillator which applies, in turn, a low voltage ac signal to the low side of a step-up high voltage transformer. The high voltage side of the transformer drives a voltage multiplier which provides a stepped up dc voltage to an output filter. The output voltage is sensed by a feedback network which then controls a regulator. Both the input and output of the regulator are on the high voltage side, avoiding isolation problems. The regulator furnishes a portion of the drive to the voltage multiplier, avoiding having a regulator in series with the load with its attendant, relatively high power losses. This power supply is highly regulated, has low power consumption, a low parts count and may be manufactured at low cost. The power supply has a programmability feature that allows for the selection of a large range of output voltages.

Castell, Karen D. (inventor); Ruitberg, Arthur P. (inventor)

1994-01-01

138

Electric power emergency handbook  

SciTech Connect

The Emergency Electric Power Administration's Emergency Operations Handbook is designed to provide guidance to the EEPA organization. It defines responsibilities and describes actions performed by the government and electric utilities in planning for, and in operations during, national emergencies. The EEPA Handbook is reissued periodically to describe organizational changes, to assign new duties and responsibilities, and to clarify the responsibilities of the government to direct and coordinate the operations of the electric utility industry under emergencies declared by the President. This Handbook is consistent with the assumptions, policies, and procedures contained in the National Plan for Emergency Preparedness. Claimancy and restoration, communications and warning, and effects of nuclear weapons are subjects covered in the appendices.

Labadie, J.R.

1980-09-01

139

Wind power. [electricity generation  

NASA Technical Reports Server (NTRS)

A historical background on windmill use, the nature of wind, wind conversion system technology and requirements, the economics of wind power and comparisons with alternative systems, data needs, technology development needs, and an implementation plan for wind energy are presented. Considerable progress took place during the 1950's. Most of the modern windmills feature a wind turbine electricity generator located directly at the top of their rotor towers.

Savino, J. M.

1975-01-01

140

Electric power transmission systems  

Microsoft Academic Search

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

J. R. Eaton; E. Cohen

1983-01-01

141

Improved detection of electrical activity with a voltage probe based on a voltage-sensing phosphatase.  

PubMed

? One of the most awaited techniques in modern physiology is the sensitive detection of spatiotemporal electrical activity in a complex network of excitable cells. The use of genetically encoded voltage probes has been expected to enable such analysis. However, in spite of recent progress, existing probes still suffer from low signal amplitude and/or kinetics too slow to detect fast electrical activity. Here, we have developed an improved voltage probe named Mermaid2, which is based on the voltage-sensor domain of the voltage-sensing phosphatase from Ciona intestinalis and Förster energy transfer between a pair of fluorescent proteins. In mammalian cells, Mermaid2 permits ratiometric readouts of fractional changes of more than 50% over a physiologically relevant voltage range with fast kinetics, and it was used to follow a train of action potentials at frequencies of up to 150 Hz. Mermaid2 was also able to detect single action potentials and subthreshold voltage responses in hippocampal neurons in vitro, in addition to cortical electrical activity evoked by sound stimuli in single trials in living mice. PMID:23836686

Tsutsui, Hidekazu; Jinno, Yuka; Tomita, Akiko; Niino, Yusuke; Yamada, Yoshiyuki; Mikoshiba, Katsuhiko; Miyawaki, Atsushi; Okamura, Yasushi

2013-09-15

142

Electric power for space satellites  

NASA Technical Reports Server (NTRS)

The development of electric power systems for satellites is discussed as an evolutionary process requiring the integration of power generation, power storage, and power control and distribution. The growth of space electric power systems is traced. The capabilities and limitations of the various elements (i.e. silicon solar cells) are discussed together with their impact on future technological growth.

Mackenzie, C. M.

1974-01-01

143

Plasma Membrane Voltage Changes during Nanosecond Pulsed Electric Field Exposure  

Microsoft Academic Search

The change in the membrane potential of Jurkat cells in response to nanosecond pulsed electric fields was studied for pulses with a duration of 60ns and maximum field strengths of ?100kV\\/cm (100 V\\/cell diameter). Membranes of Jurkat cells were stained with a fast voltage-sensitive dye, ANNINE-6, which has a subnanosecond voltage response time. A temporal resolution of 5ns was achieved

W. Frey; J. A. White; R. O. Price; P. F. Blackmore; R. P. Joshi; R. Nuccitelli; S. J. Beebe; K. H. Schoenbach; J. F. Kolb

2006-01-01

144

The design, construction, and operation of long-distance high-voltage electricity transmission technologies.  

SciTech Connect

This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these conductors at a safe distance from each other and from the ground and the natural and built environment. Common elements that are generally less visible (or at least more easily overlooked) include the maintained ROW along the path of the towers, access roads needed for maintenance, and staging areas used for initial construction that may be restored after construction is complete. Also visible but less common elements along the corridor may include switching stations or substations, where lines of similar or different voltages meet to transfer power.

Molburg, J. C.; Kavicky, J. A.; Picel, K. C.

2008-03-03

145

Effect of transformer on stochastic estimation of voltage sag due to faults in the power system: a PSCAD\\/EMTDC simulation  

Microsoft Academic Search

Voltage sags in the electric power system are mostly due to faults in the power system. Voltage sag is characterized by its magnitude (the retained voltage), phase-angle jump, unbalance in the sag in the three phases, and duration. Type of transformers in the electrical system is the important parameter influencing the characteristic of sag at the node where sensitive loads

Nita R. PATNE; K. L. THAKRE

2010-01-01

146

Arc lamp power supply using a voltage multiplier  

NASA Technical Reports Server (NTRS)

A power supply is provided for an arc discharge lamp which includes a relatively low voltage high current power supply section and a high voltage starter circuit. The low voltage section includes a transformer, rectifier, variable resistor and a bank of capacitors, while the starter circuit comprises several diodes and capacitors connected as a Cockcroft-Walton multiplier. The starting circuit is effectively bypassed when the lamp arc is established and serves to automatically provide a high starting voltage to re-strike the lamp arc if the arc is extinguished by a power interruption.

Leighty, Bradley D.

1988-01-01

147

Method of assessment of the state of charge and voltage level in the electric power distribution network. Implementation in the improvement of supply quality  

Microsoft Academic Search

Nowadays in order to know in real time the level of charge existing in a distribution network, the installation of a remote infrastructure of operation and supervision is necessary, allowing an immediate view of its electrical state, both normal operation as well as in case of incident. The analysis of the state of the network provides useful data for the

J. I. García-Román; E. Gonzalez-Romera; F. Barrero-González; D. Carmona-Fernández; J. A. Álvarez-Moreno

2006-01-01

148

Calibration of high voltage transducers for power quality measurements  

Microsoft Academic Search

Transmission and distribution networks are increasingly affected by sensitive loads, considering the increase of power electronics based equipment and devices. For keeping under control power quality parameters, for instance, harmonics, sags, swells, flicker, reliable measurements performed at high voltage level are necessary. This kind of measurement is performed using high voltage transducers. Considering present technical standards on this subject, for

HÉDIO TATIZAWA; ERASMO SILVEIRA NETO; GERALDO F. BURANI; ANTÔNIO A. C. ARRUDA; KLEIBER T. SOLETTO; NELSON M. MATSUO

2009-01-01

149

Medium power voltage multipliers with a large number of stages  

NASA Technical Reports Server (NTRS)

Voltage multiplier techniques are extended at medium power levels to larger multiplication ratios. A series of dc-dc converters were built, with from 20 to 45 stages and with power levels up to 100 watts. Maximum output voltages were about 10,000 volts.

Harrigill, W. T.; Myers, I. T.

1978-01-01

150

Optimal reactive power and voltage control for radial distribution system  

Microsoft Academic Search

A new approach to optimal reactive power and voltage control problem in a radial distribution system is proposed in this paper. The optimal control problem is to find a proper dispatch schedule for shunt capacitor banks and on-load tap changer at substation and shunt capacitor banks on feeders such that the power loss is minimized and the voltage profile is

Yutian Liu; Peng Zhang; Xizhao Qiu

2000-01-01

151

A Control Method of Inverter used for Distributed Power Supply under Voltage Sag Condition  

NASA Astrophysics Data System (ADS)

Inverter which is used for distributed power supply, such as solar cell or fuel cell system, tends to stop easily by voltage sag. In the present electric power system, there is little problem by this characteristic of inverter. But if the number of those inverters connected to power system increases, the quality of system voltage and frequency may deteriorate by stop of the inverters. In addition, about fuel cell system, its output power cannot be controlled quickly, and the whole system may stop by a rise of inside temperature. For these problems, we tried to realize high continuous operation ability of inverter used for distributed power supply under voltage sag condition. This paper shows a control method of inverter for the over current caused by sudden change or unbalance of the system voltage and examination results with 3-phase 200V-4kW class inverter system.

Hatano, Nobuhiko; Taniguchi, Yuji; Kouchi, Katsuhiko

152

High voltage power supply with modular series resonant inverters  

DOEpatents

A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360.degree./n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit.

Dreifuerst, Gary R. (Livermore, CA); Merritt, Bernard T. (Livermore, CA)

1995-01-01

153

High voltage power supply with modular series resonant inverters  

DOEpatents

A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360{degree}/n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit. 11 figs.

Dreifuerst, G.R.; Merritt, B.T.

1995-07-18

154

Dispatching power system for preventive and corrective voltage collapse problem in a deregulated power system  

NASA Astrophysics Data System (ADS)

Deregulation has brought opportunities for increasing efficiency of production and delivery and reduced costs to customers. Deregulation has also bought great challenges to provide the reliability and security customers have come to expect and demand from the electrical delivery system. One of the challenges in the deregulated power system is voltage instability. Voltage instability has become the principal constraint on power system operation for many utilities. Voltage instability is a unique problem because it can produce an uncontrollable, cascading instability that results in blackout for a large region or an entire country. In this work we define a system of advanced analytical methods and tools for secure and efficient operation of the power system in the deregulated environment. The work consists of two modules; (a) contingency selection module and (b) a Security Constrained Optimization module. The contingency selection module to be used for voltage instability is the Voltage Stability Security Assessment and Diagnosis (VSSAD). VSSAD shows that each voltage control area and its reactive reserve basin describe a subsystem or agent that has a unique voltage instability problem. VSSAD identifies each such agent. VS SAD is to assess proximity to voltage instability for each agent and rank voltage instability agents for each contingency simulated. Contingency selection and ranking for each agent is also performed. Diagnosis of where, why, when, and what can be done to cure voltage instability for each equipment outage and transaction change combination that has no load flow solution is also performed. A security constrained optimization module developed solves a minimum control solvability problem. A minimum control solvability problem obtains the reactive reserves through action of voltage control devices that VSSAD determines are needed in each agent to obtain solution of the load flow. VSSAD makes a physically impossible recommendation of adding reactive generation capability to specific generators to allow a load flow solution to be obtained. The minimum control solvability problem can also obtain solution of the load flow without curtailing transactions that shed load and generation as recommended by VSSAD. A minimum control solvability problem will be implemented as a corrective control, that will achieve the above objectives by using minimum control changes. The control includes; (1) voltage setpoint on generator bus voltage terminals; (2) under load tap changer tap positions and switchable shunt capacitors; and (3) active generation at generator buses. The minimum control solvability problem uses the VSSAD recommendation to obtain the feasible stable starting point but completely eliminates the impossible or onerous recommendation made by VSSAD. This thesis reviews the capabilities of Voltage Stability Security Assessment and Diagnosis and how it can be used to implement a contingency selection module for the Open Access System Dispatch (OASYDIS). The OASYDIS will also use the corrective control computed by Security Constrained Dispatch. The corrective control would be computed off line and stored for each contingency that produces voltage instability. The control is triggered and implemented to correct the voltage instability in the agent experiencing voltage instability only after the equipment outage or operating changes predicted to produce voltage instability have occurred. The advantages and the requirements to implement the corrective control are also discussed.

Alemadi, Nasser Ahmed

155

Voltage saturation in electrical contacts via viscoplastic creep  

SciTech Connect

Electrical contact resistance affects the performance of electrical switches and other current-carrying interfaces. This study investigates the behavior of electrical contact resistance for copper copper and aluminum aluminum sphere-on-flat contact as a function of current through the interface. It is observed that the contact resistance may either increase or decrease with increasing current, depending on the current level as well as the current history. At low current levels the voltage drop across the interface increases initially with increasing current until it saturates. The voltage level remains nearly constant even if the current is increased beyond the value corresponding to saturation. Hereafter any subsequent decrease in current yields a corresponding decrease in voltage, so that the associated current cycle shows substantial hysteresis. However, subsequent cycles of current are reversible so long as the voltage remains below the saturation point. Analyses of the results suggest that the mechanism of viscoplastic creep is responsible for the voltage saturation phenomenon. 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Streator, Jeffrey L [ORNL; Bansal, Dinesh G [ORNL

2011-01-01

156

Power electronics in electric utilities: Static var compensators  

Microsoft Academic Search

This paper deals with dynamic var compensation of electric power systems, applying power electronics for reactive power generation and control. After an overview of the emergence and status of modern, solid-state var compensators in utility and industrial applications, the first part of the paper explains how dynamic var compensation increases transmittable power by providing voltage support, transient stability improvement, and

L. Gyugyi

1988-01-01

157

Case study: visualization of an electric power transmission system  

Microsoft Academic Search

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

Pramod M. Mahadev; Richard D. Christie

1994-01-01

158

Low Power, High Voltage Power Supply with Fast Rise/Fall Time  

NASA Technical Reports Server (NTRS)

A low power, high voltage power supply system includes a high voltage power supply stage and a preregulator for programming the power supply stage so as to produce an output voltage which is a predetermined fraction of a desired voltage level. The power supply stage includes a high voltage, voltage doubler stage connected to receive the output voltage from the preregulator and for, when activated, providing amplification of the output voltage to the desired voltage level. A first feedback loop is connected between the output of the preregulator and an input of the preregulator while a second feedback loop is connected between the output of the power supply stage and the input of the preregulator.

Bearden, Douglas B. (Inventor)

2007-01-01

159

Low power, high voltage power supply with fast rise/fall time  

NASA Technical Reports Server (NTRS)

A low power, high voltage power supply system includes a high voltage power supply stage and a preregulator for programming the power supply stage so as to produce an output voltage which is a predetermined fraction of a desired voltage level. The power supply stage includes a high voltage, voltage doubler stage connected to receive the output voltage from the preregulator and for, when activated, providing amplification of the output voltage to the desired voltage level. A first feedback loop is connected between the output of the preregulator and an input of the preregulator while a second feedback loop is connected between the output of the power supply stage and the input of the preregulator.

Bearden, Douglas B. (Inventor)

2007-01-01

160

Electric arc furnace power modeling for STATCOM Controller Application  

Microsoft Academic Search

The nonlinear and time varying nature of electric arc furnaces (EAFs) creates flicker, harmonics, and voltage\\/current unbalances. Nowadays to improve the performance of EAFs and the power quality problems of electrical systems around them high speed compensators like STATCOM are needed. This paper uses a time domain model for electric arc furnaces and a new model is proposed for EAFs.

Y. Najafi Sarem; M. H. Amrollahi; M. Babanejad; S. Mounesirad; M. A. Layegh; D. Habibinia

2010-01-01

161

A single-phase voltage sag generator for testing electrical equipments  

Microsoft Academic Search

This paper describes a transformer-based voltage sag generator (VSG) suitable to evaluate the susceptibility of electrical equipment to voltage sag. The built VSG utilized one auto-transformer and two solid state relays (SSRs) to provide nominal voltage and sag voltage to the load. The switch statuses of two SSRs are controlled by nominal voltage and sag voltage duration signal produced by

Yan Ma; George G. Karady

2008-01-01

162

The advantages of the high voltage solar array for electric propulsion  

NASA Technical Reports Server (NTRS)

The high voltage solar array (HVSA) offers improvements in efficiency, weight, and reliability for the electric propulsion power system. The basic HVSA technology involves designing the solar array to deliver power in the form required by the ion thruster. This paper delves into conventional power processes and problems associated with ion thruster operation using SERT II experience for examples. In this light, the advantages of the HVSA concept for electric propulsion are presented. Tests conducted operating the SERT II thruster system in conjunction with HVSA are discussed. Thruster operation was observed to be normal and in some respects improved.

Sater, B. L.

1973-01-01

163

Effects of neutral point reactors and series capacitors on geomagnetically induced currents in a high-voltage electric power transmission system  

NASA Astrophysics Data System (ADS)

Geomagnetically induced currents (GIC) are DC-like currents compared to power transmission frequencies. Consequently, it may be possible to reduce the magnitudes of GIC by installing resistive components or series capacitors into a power grid. We simulate the effects of neutral point reactors and series capacitors on GIC in the Finnish 400 kV network. Reactors add an additional resistance to earthing leads of transformers, and series capacitors block the flow of GIC in transmission lines. The geoelectric field impacting the system is considered to be uniform. The use of reactors does not necessarily reduce the GIC risk. Although the installation of reactors tends to decrease GIC on the average, maximum GIC may even increase. Assuming a reactor at all stations results in a 50% reduction of the maximum GIC compared to the situation with no reactors. With up to four series capacitors, the maximum GIC is reduced by 40% when they are optimally located. However, even small changes in the topology of the grid can cause large changes in GIC. A combination of reactors and series capacitors could in principle provide a way to diminish the GIC risk. This study also emphasizes the difficulty of preventing GIC problems by these means.

ArajäRvi, Esko; Pirjola, Risto; Viljanen, Ari

2011-11-01

164

Voltage control availability of distributed generators in power distribution system  

Microsoft Academic Search

In spite of many profitable or advantageous natures of distributed generators (DGs), for power systems, such badly behaved natures of DGs as (1) unstable power output, (2) voltage problem, (3)harmonics, (4)reverse power flow, etc. also exist. Therefore, it has been always emphasized that the unfavorable effects should not exist when distributed generators are connected to the power system. However, in

K. Nara; S. Ishizu; Y. Mishima

2005-01-01

165

Power processing units for high power solar electric propulsion  

NASA Astrophysics Data System (ADS)

An evaluation of high-power processing units (PPUs) for multimegawatt solar electric propulsion (SEP) vehicles using advanced ion thrusters is presented. Significant savings of scale are possible for PPUs used to supply power to ion thrusters operating at 0.1 to 1.5 MWe per thruster. The PPU specific mass is found to be strongly sensitive to variations in the ion thruster's power per thruster and moderately sensitive to variations in the thruster's screen voltage due to varying the I(sp) of the thruster. Each PPU consists of a dc-to-dc converter to increase the voltage from the 500 V dc of the photovoltaic power system to the 5 to 13 kV dc required by the ion thrusters.

Frisbee, Robert H.; Das, Radhe S.; Krauthamer, Stanley

166

Power processing units for high power solar electric propulsion  

NASA Technical Reports Server (NTRS)

An evaluation of high-power processing units (PPUs) for multimegawatt solar electric propulsion (SEP) vehicles using advanced ion thrusters is presented. Significant savings of scale are possible for PPUs used to supply power to ion thrusters operating at 0.1 to 1.5 MWe per thruster. The PPU specific mass is found to be strongly sensitive to variations in the ion thruster's power per thruster and moderately sensitive to variations in the thruster's screen voltage due to varying the I(sp) of the thruster. Each PPU consists of a dc-to-dc converter to increase the voltage from the 500 V dc of the photovoltaic power system to the 5 to 13 kV dc required by the ion thrusters.

Frisbee, Robert H.; Das, Radhe S.; Krauthamer, Stanley

1992-01-01

167

New methods for computing a closest saddle node bifurcation and worst case load power margin for voltage collapse  

Microsoft Academic Search

Voltage collapse and blackout can occur in an electric power system when load powers vary so that the system loses stability in a saddle node bifurcation. The authors propose new iterative and direct methods to compute load powers at which bifurcation occurs and which are locally closest to the current operating load powers. The distance in load power parameter space

Ian Dobson; Liming Lu

1993-01-01

168

Scrambling on electrical power grids  

Microsoft Academic Search

Deregulated, the U.S. electrical power grid system has shown the emergence of behaviors that include scrambling by buyers to purchase electricity and unexpected increasing costs of electricity to consumers. To infer those behaviors, in this paper, we adapt a theoretical framework, developed by Newman in his work on spread of epidemic disease on networks, to the propagation of electricity buying

Thomas V. Huynh; John S. Osmundson

2008-01-01

169

Generalized theory of electric power  

Microsoft Academic Search

Contents The paper presents the generalized theory of electric power, which makes it possible to estimate the operation of complex electric circuits. Use has been made of the correlation analysis and new definitions have been found for various kinds of power occurring in such systems. It has been shown that both the active and the reactive power depend on the

Z. Nowomiejski

1981-01-01

170

Bidirectional power electronic transformer based compact dynamic voltage restorer  

Microsoft Academic Search

In this paper a dynamic voltage restorer (DVR) circuit with a bi-directional power electronic transformer (PET) structure is proposed to correct input utility voltage distortions on a sensitive load. This DVR-PET contains full-bridge DC-link inverter (FBDCI), high frequency isolating transformer (HFIT), cyclo-converter and output filter. A phase shift modulation (PSM) control scheme is used to regulate compensation voltage. The proper

S. H. Hosseini; M. B. B. Sharifian; M. Sabahi; A. Y. Goharrizi; G. B. Gharehpetian

2009-01-01

171

Voltage Sensor  

NASA Technical Reports Server (NTRS)

Under a Lewis Research Center Small Business Innovation Research contract, SRICO, Inc. developed a fiber optic voltage sensor to measure voltage in electronic systems in spacecraft. The sensor uses glass and light to sense and transmit electricity, and is relatively safe and accurate. SRICO then commercialized the sensor for measurement of electric field and voltage in applications such as electric power systems and hazardous environments, lightning detection, and fiber optic communication systems.

1996-01-01

172

Robust distribution and use of electric power  

NASA Astrophysics Data System (ADS)

One of the major problems related to the simultaneous operation of electrical converters in a wide open power system is the concordance between the characteristics of the feeder itself and the load. Nowadays we usually call Electric Power Quality or Electromagnetic Compatibility to this Concordance Degree. Currently, the most important non concordance are voltage sag (voltage dip) and short time interruptions, that is: decreasings in voltage RMS value lasting from some tenths of a second to several seconds. Current analysis usually study this problem from the feeder side, by means of morphological or stadistical approaches, or from the load side in order to evaluate immunity, emission or specific solutions. This line of research, undoubtly needed provided we need to know the current state of the power system and to increase the concordance degree, is not enough because of the huge variability between power lines and from one instant to another. Moreover, the legal boundaries that can support business decisions are not developed yet. The proposed new theory is widely contrasted by field and laboratory measurement. Detailed analysis include instant voltage, instant current, power system and load effects from many places inside the power system of Spain. This theory is a novel approach to the determination of Concordance Degree (CG) of a whole system (be it a distribution line or a single machine) and to the corrective steps needed to increase it. In addition, the proposed model allow a quantitative evaluation of corrective actions like the increase of energy system storage (in a mechanical to electrical convertible form) or/and the increase of the supplied reactive power. Profitability of corrective actions is mainly a function of the number of voltage dips (sags) and short time interruptions that happen in a given period of time. To reduce this number we have studied and developed new fault characterization and location algorithms designed specifically for medium voltage networks. These algorithms, applied to the recorded faults obtained in the widespread measure campaign we have performed, have allowed the analysis of the Fault Repeatness. Last, new lines of research are suggested, mainly focused on more detailed analytical models together with laboratory and field experiences, in order to provide a solid ground for the development of a realistic standard environment able to provide the highest Concordance Degree at the lowest system-as-a-whole cost.

Catalan Izquierdo, Saturnino

2001-07-01

173

Sinusoidal voltage controller for uninterruptible power supply by robust control  

Microsoft Academic Search

The output voltage of an uninterruptible power supply (UPS) is distorted by nonlinear loads. To obtain sinusoidal output voltage of a UPS, a new control method of a pulse width modulated (PWM) inverter is proposed applying sliding mode control. The feedback gains of conventional sliding mode control are determined by offline calculation; however this proposed control method calculates the feedback

Tomonobu Senjyu; Katsumi Uezato

1993-01-01

174

Experimental investigation on voltage stability in vehicle power nets for power distribution management  

Microsoft Academic Search

The power demand and the complexity of vehicle power nets has increased continuously during the last years. Especially the high demands of chassis control systems can cause voltage drops that endanger the power net's stability. A power net test bench that enables experimental research on voltage stability in vehicular power nets is presented in this paper. Thereby the relevance of

Tom P. Kohler; Thomas Wagner; Andreas Thanheiser; Christiane Bertram; Dominik Buecherl; Hans-Georg Herzog; Joachim Froeschl; Rainer Gehring

2010-01-01

175

Advanced electric propulsion system concept for electric vehicles. Addendum 1. Voltage considerations  

Microsoft Academic Search

Seventeen electric vehicle propulsion systems were originally studied to select two designs that best met cost and performance goals. Both systems have now been examined to assess the effect of battery pack voltage on system performance and cost. A voltage range of 54 to 540 V was considered for a typical battery pack capacity of 24 kW-hr. The highest battery

A. E. Raynard; F. E. Forbes

1980-01-01

176

Electrical Power Systems for MARS.  

National Technical Information Service (NTIS)

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, nuclea...

R. J. Giudici

1986-01-01

177

A Field Study of Lightning Surges Propagating through Low-voltage Electric Appliances  

NASA Astrophysics Data System (ADS)

In today's highly information-based society, lightning damage has a significant impact on an increasing number of electric appliances such as personal computers and facsimile machines. Lightning surge protection devices for electric appliances are on the market and concern for lightning protection has been increasing, but there are still many unknown aspects of lightning surges that propagate into residences. To provide effective lightning protection measures, clarification of surge propagation patterns is needed. The Tokyo Electric Power Company has observed the patterns of lightning surge propagation into houses using lightning surge waveform detectors installed at ordinary residences and obtained data on 30 lightning surge current waveforms between 2008 and 2009. This paper discusses various aspects of lightning surge currents propagating into low-voltage appliances, including home electric appliances, based on the lightning surge current waveform data obtained from lightning observations. The result revealed the patterns of lightning surge currents propagating into the ground and lines of low-voltage appliances.

Ishii, Tsunayoshi; Sakamoto, Yoshiki; Oguchi, Shuichi; Okabe, Shigemitsu

178

Power quality monitoring for electric substation ancillary services supplying  

Microsoft Academic Search

Power quality is the study of the sources, effects and control of disturbances which propagate via the electric power supply. The disturbances change the supply RMS voltage or its waveform (or very occasionally the frequency) and may originate from various sources. Within the paper, the authors are focusing on power quality monitoring. The presented approach refers to substation ancillary services

N. Chiosa; S. Kilyeni; C. Barbulescu; D. Jigoria-Oprea

2010-01-01

179

Epitaxial ?-? n-p-n high-voltage power transistors  

Microsoft Academic Search

A new silicon power-transistor structure has been developed which expands the frontiers of power-switching performance and high-voltage power-handling capability. This new structure employs a unique ?-? (nearly intrinsic p- and n-type) epitaxial-layer construction which utilizes \\

R. Denning; D. A. Moe

1970-01-01

180

Power voltage current convertor using quasi complementary MOSFET current mirrors  

PubMed Central

A voltage current convertor is described having a quasi complementary class AB architecture that is particularly suited to implementation using discrete power MOSFETs. High-voltage mirror designs are presented, enabling the construction of sources with kilovolt compliance range, tens of watts of output power and greater than 100 kHz bandwidth. G? output impedance and distortion below 1% can be obtained with no trimming or transistor matching.

MacLachlan, R. A.; Riviere, C. N.

2011-01-01

181

Power voltage current convertor using quasi complementary MOSFET current mirrors.  

PubMed

A voltage current convertor is described having a quasi complementary class AB architecture that is particularly suited to implementation using discrete power MOSFETs. High-voltage mirror designs are presented, enabling the construction of sources with kilovolt compliance range, tens of watts of output power and greater than 100 kHz bandwidth. G? output impedance and distortion below 1% can be obtained with no trimming or transistor matching. PMID:22312182

Maclachlan, R A; Riviere, C N

2011-10-13

182

Student's understanding of voltage in simple parallel electric circuits  

NSDL National Science Digital Library

This paper reports an investigation of the performance of school students at age 15 on written diagnostic questions involving the prediction of meter readings in simple electric circuits with parallel branches. Results show that these students tend to perceive such questions in resistance-current terms, with a primary focus on resistor addition, rather than in voltage terms, with two loads being driven from the same source. Common errors in predicting voltages across parallel branches suggest that few students use a mental model of solving parallel circuit problems but instead attempt to solve problems by mechanical use of the V=IR equation. Implications for the teaching of electric circuits at this level are identified.

Millar, Robin; Beh, K. L.

2006-06-19

183

Electric power applications of superconductivity  

Microsoft Academic Search

The development of superconducting systems for electric power is driven by the promise of improved efficiency, smaller size, and reduced weight as compared to existing technologies and by the possibility of new applications. Superconducting power components can also contribute to improved power quality and increased system reliability. This paper addresses historical developments and technology status of four superconducting power applications:

WILLIAM V. HASSENZAHL; DREW W. HAZELTON; BRIAN K. JOHNSON; PETER KOMAREK; MATHIAS NOE; CHANDRA T. REIS

2004-01-01

184

Integration of D-Statcom based photovoltaic cell power in low voltage power distribution grid  

Microsoft Academic Search

The main aim of this paper is the voltage regulation which is one of the most important operational requirement in power network at both transmission and distribution levels. Whenever there is a penetration of photovoltaic cell power to the low voltage distributed grid, there occur the problem of mismatch in voltage and frequency in the network, perhaps caused by non

R. Indumathi; M. Venkateshkumar; R. Raghavan

2012-01-01

185

A high voltage dielectrically isolated smart power technology based on silicon direct bonding  

NASA Astrophysics Data System (ADS)

The feasibility of a dielectrically isolated technology based on the silicon direct bonding technique, for high voltage smart power applications in the 1000 to 1550 V/1 to 20 A range, where a vertical power switch is necessary, is investigated and demonstrated. Static and dynamic isolation of the low voltage circuitry integrated beside the vertical power transistor is the main concern of this family of circuits. The dielectric isolation offers better protection to the low voltage part than does the junction isolation, because of the elimination of the parasitic bipolar transistor inherent to the latter isolation technique. Silicon direct bonding provides a cost effective way to obtain a buried oxide isolation layer. In addition, the application requires a Si/Si bonded area in the active region of the vertical power switch. Strong influence of the prebonding cleaning in the electrical characteristics of the Si/Si interface is pointed out, and presence of crystalline defects is assumed to be at the origin of electrical failures. The main problems of silicon direct bonding process compatibility with standard processes were overcome, and a complete process flow, including the simultaneous integration of a vertical power bipolar transistor together with a bipolar control circuitry, was validated. Using a peripheral biased ring is shown to provide an easy way to optimize high voltage termination for the smart power circuit, while adding a non-additional technological step. This technique was studied by dimensional electrical simulations (BIDIM2 software), as well as analytically computed.

Macary, Veronique

1992-09-01

186

Wind power electrical generator system  

Microsoft Academic Search

A wind power electrical generator system having improved efficiency including a wind mill which activates an air compressor to generate a supply of pressurized air. An air motor activated by the supply of pressurized air drives a generator to produce electrical power. A waste air recovery mechanism, activated by the waste air from the air motor produces rotary energy assisting

Allison

1984-01-01

187

Electric-Power System Simulator  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

188

Source electrode evolution of a low voltage power MOSFET under avalanche cycling  

Microsoft Academic Search

This paper presents the impact of high current repetitive avalanche pulses on a low voltage vertical power MOSFET at high temperature. Measurements show that RDSon decreases with the number of avalanche cycles whereas other electrical parameters stay constant. A simple model proposed in this paper shows that RDSon measurements are linked to MOSFET source electrode evolution. Also once source electrode

B. Bernoux; R. Escoffier; P. Jalbaud; J. M. Dorkel

2009-01-01

189

NASCAP modelling of high-voltage power system interactions with space charged-particle environments  

NASA Technical Reports Server (NTRS)

A simple space power system operating in geosynchronous orbit was analyzed. This system consisted of two solar array wings and a central body. Each solar array wing was considered to be divided into three regions operating at 2000 volts. The center body was considered to be an electrical ground with the array voltages both positive and negative relative to ground. The system was analyzed for both a normal environment and a moderate geomagnetic substorm environment. Initial results indicate a high probability of arcing at the interconnects on the negative operating voltage wing. The dielectric strength of the substrate may be exceeded giving rise to breakdown in the bulk of the material. The geomagnetic substorm did not seem to increase the electrical gradients at the interconnects on the negative operating voltage wing but did increase the gradients on the positive operating voltage wing which could result in increased coupling current losses.

Stevens, N. J.; Roche, J. C.; Mandell, M. J.

1979-01-01

190

Programmable timed electrical power management device  

SciTech Connect

A programmable timed electrical power management device protects and controls electrical equipment and peripherals which are plugged into it. The front of the housing containing the electrical circuitry is provided with a LCD display, a series of pressure sensitive switches for inputting function and control commands to control the operation of the device. A series of LED's mounted on the front of the housing indicate the operational status of the device. The back of the housing is provided with an AC power input receptacle, an on/off reset switch, a series of AC outlets which are divided into pairs of filtered banks, and two or more modular jacks for receiving the modular plug of a telephone, fax, and/or modem. The device circuitry includes a CPU, timer/calendar, a sound generator, voltage sensors, and a back-up battery power supply. The outlets and modular plugs are protected from electrical surges. Each bank of outlets can be selectively programmed to turn on and off at a different time of the day and different days of the week. When more than one bank is set to start at the same time, power is sequentially supplied to each electrical outlet bank allowing the voltage to stabilize before turning on the next bank. A warning tone will sound fifteen, ten, and five minutes prior to shutting off any of the banks, to alert the user that the system is approaching the preset time for the power to the outlets to be turned off, to prevent accidental loss of information. 9 figs.

Nyenya, S.S.

1994-01-11

191

Voltage Stability Impact of Grid-Tied Photovoltaic Systems Utilizing Dynamic Reactive Power Control  

NASA Astrophysics Data System (ADS)

Photovoltaic (PV) DGs can be optimized to provide reactive power support to the grid, although this feature is currently rarely utilized as most DG systems are designed to operate with unity power factor and supply real power only to the grid. In this work, the voltage stability of a power system embedded with PV DG is examined in the context of the high reactive power requirement after a voltage sag or fault. A real-time dynamic multi-function power controller that enables renewable source PV DGs to provide the reactive power support necessary to maintain the voltage stability of the microgrid, and consequently, the wider power system is proposed. The loadability limit necessary to maintain the voltage stability of an interconnected microgrid is determined by using bifurcation analysis to test for the singularity of the network Jacobian and load differential equations with and without the contribution of the DG. The maximum and minimum real and reactive power support permissible from the DG is obtained from the loadability limit and used as the limiting factors in controlling the real and reactive power contribution from the PV source. The designed controller regulates the voltage output based on instantaneous power theory at the point-of-common coupling (PCC) while the reactive power supply is controlled by means of the power factor and reactive current droop method. The control method is implemented in a modified IEEE 13-bus test feeder system using PSCADRTM power system analysis software and is applied to the model of a Tampa ElectricRTM PV installation at Lowry Park Zoo in Tampa, FL. This dissertation accomplishes the systematic analysis of the voltage impact of a PV DG-embedded power distribution system. The method employed in this work bases the contribution of the PV resource on the voltage stability margins of the microgrid rather than the commonly used loss-of-load probability (LOLP) and effective load-carrying capability (ELCC) measures. The results of the proposed method show good improvement in the before-, during-, and post-start voltage levels at the motor terminals. The voltage stability margin approach provides the utility a more useful measure in sizing and locating PV resources to support the overall power system stability in an emerging smart grid.

Omole, Adedamola

192

Design considerations for high-voltage DC bus architecture and wire mechanization for hybrid and electric vehicle applications  

Microsoft Academic Search

In electric and hybrid electric vehicle applications high-voltage (HV) DC bus is shared by multiple power converter units and energy storage systems. Each of these components should meet a set of common HV bus design requirements besides their own functional requirements. Selection of an appropriate HV DC bus architecture is intertwined with control dynamics and filter component sizing, together with

Mohammad N. Anwar; Sean E. Gleason; Timothy M. Grewe

2010-01-01

193

Shunt regulation electric power system  

NASA Technical Reports Server (NTRS)

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.

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

1971-01-01

194

High-voltage electrical burn injuries: functional upper extremity assessment.  

PubMed

High-voltage electric injuries have many manifestations, and an important complication is the damage of the central/peripheral nervous system. The purpose of this work was to assess the upper limb dysfunction in patients injured by high-voltage current. The evaluation consisted of analysis of patients' records, cutaneous-sensibility threshold, handgrip and pinch strength and a specific questionnaire about upper limb dysfunctions (DASH) in 18 subjects. All subjects were men; the average age at the time of the injury was 38 years. Of these, 72% changed job/retired after the injury. The current entrance was the hand in 94% and grounding in the lower limb in 78%. The average burned surface area (BSA) was 8.6%. The handgrip strength of the injured limb was reduced (p<0.05) and so also that of the three pinch types. The relationship between the handgrip strength and the DASH was statistically significant (p<0.001) as well as the relationship between the three pinch types (pvoltage electrical shock. PMID:19203837

Mazzetto-Betti, K C; Amâncio, A C G; Farina, J A; Barros, M E P M; Fonseca, M C R

2009-08-01

195

Coordinated reactive power planning against power system voltage instability  

Microsoft Academic Search

This paper implements a long term VAR planning algorithm developed earlier, which coordinates between network investments that most effectively address steady-state voltage instability and those which most effectively address transient voltage dip problems under severe contingencies. The algorithm is applied on a portion of a large scale system consisting of 16173 buses representing the eastern interconnection. The planning method is

Venkat Krishnan; Haifeng Liu; James D. McCalley

2009-01-01

196

Voltage Reactive Power Control with Multi Objective Particle Swarm Optimization  

NASA Astrophysics Data System (ADS)

The purpose of this research is to minimize a transmission loss and the number of times of VAR devices motions in power system. We formulate Voltage Reactive Power Control (VQC) with Particle Swarm Optimization (PSO) on this problem, and propose Multi Objective PSO (MOPSO) whose objective functions are a transmission loss and the number of times of VAR devices motions.

Sugimoto, Kazuki; Ishigame, Atsushi; Yasuda, Keiichiro

197

Low-voltage power system surge overvoltage protection  

Microsoft Academic Search

The unpredictable threat of transient overvoltages is ever increasing in today's low-voltage power supplies for every aspect of industry. To calculate the magnitude, duration and energy of such transient overvoltages is not an easy task. Some loads are becoming very sensitive to such overvoltages, thereby creating a challenge for the application engineer to design a reliable power supply system. To

Dev Paul

2001-01-01

198

A zero-voltage-switching controlled high-power-factor converter for DC uninterruptible power supply  

Microsoft Academic Search

A new zero-voltage-switching controlled high-power-factor power converter suitable for a DC uninterruptible power supply is proposed. A control method for achieving zero voltage switching (ZVS) without auxiliary switches is examined. ZVS operations and power-factor characteristics in the power converter are analyzed and verified experimentally. A power-factor of 0.99 and conversion efficiency of 88% were measured using a bread-board circuit

Akira TAKEUCHI; Satoshi OHTSU; S. Muroyama

1996-01-01

199

Multiple high voltage output DC-to-DC power converter  

NASA Technical Reports Server (NTRS)

Disclosed is a multiple output DC-to-DC converter. The DC input power is filtered and passed through a chopper preregulator. The chopper output is then passed through a current source inverter controlled by a squarewave generator. The resultant AC is passed through the primary winding of a transformer, with high voltages induced in a plurality of secondary windings. The high voltage secondary outputs are each solid-state rectified for passage to individual output loads. Multiple feedback loops control the operation of the chopper preregulator, one being responsive to the current through the primary winding and another responsive to the DC voltage level at a selected output.

Cronin, Donald L. (Inventor); Farber, Bertrand F. (Inventor); Gehm, Hartmut K. (Inventor); Goldin, Daniel S. (Inventor)

1977-01-01

200

Facts allocation for power systems voltage stability enhancement using MOPSO  

Microsoft Academic Search

Location of the static VAR compensator (SVC) and other types of FACTS devices is important for the enhancement of practical power systems voltage stability. In this paper, a Multi-objective particle swarm optimization (MOPSO) is used to solve a mixed continuous-discrete multi-objective optimization problem in order to find optimal location of FACTS. Various objectives are considered, namely voltage stability improvement, real

A. Laifa; M. Boudour

2008-01-01

201

High voltage spiral generators for electric propulsion applications  

NASA Astrophysics Data System (ADS)

The principles of Spiral Line Vector Inversion Generators is introduced and described in terms of frequency, efficiency and pulsed power levels for space applications. Spiral generators are a variant of the familiar Blumlein voltage doubler. They allow the production of high voltage-high power radio frequency energy from electrostatically stored energy in a one-step one component process. They are extremely simple devices to build and demonstrate. Spiral line vector inversion generators can operate as a pulser or in an oscillator mode. In the oscillator mode, devices have been built by the author that can operate at frequencies as high as 200 Mhz at peak power levels in excess of 50 megawatts. At lower frequencies, devices have been built which operate at the megavolt level at about 10 Mhz. Energy storage and conversion efficiency are on the order of 2-3 kilojoules/pulse for large generators and greater than 50% respectively in optimum geometry. Average power is determined by the repetition rate. This paper will describe the state of the art for these generators, present the performance of several small laboratory units and show how they can be used to power small thrusters such as rf arcjets. Problems and limitations will be discussed within the context of space applications. .

Rose, M. Franklin

2002-01-01

202

Electrical power systems for Mars  

NASA Astrophysics Data System (ADS)

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

Giudici, Robert J.

1986-05-01

203

High Voltage Power Supply With High Output Current and Low Power Consumption for Photomultiplier Tubes  

Microsoft Academic Search

In some applications, photomultiplier tubes (PMTs) are powered by battery based circuits, where the available energy is severely limited. The most simple approach to design high voltage power supplies (HVPS) for PMTs has considered resistive voltage dividers in order to bias the dynodes. However, this approach usually results in high power losses and, consequently, this undermines the PMT performance. In

José Paulo V. S. Cunha; Marcia Begalli; Maria Dias Bellar

2012-01-01

204

High voltage power supply with low power consumption for photomultiplier tubes  

Microsoft Academic Search

In some applications, photomultiplier tubes (PMTs) are powered by battery based circuits, where the available energy is severely limited. The most simple approach to design high voltage power supplies (HVPS) for PMTs has considered resistive voltage dividers in order to bias the dynodes. However, this approach usually results in high power losses and, consequently, this undermines the PMT performance. In

Jose Paulo V. S. Cunha; Marcia Begalli; Maria D. Bellar

2010-01-01

205

Electric power monthly, May 1993  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the US, Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions.

Not Available

1993-05-25

206

Extra high voltage power transmission. (Latest citations from the Compendex database). Published Search  

SciTech Connect

The bibliography contains citations concerning the design, construction, and testing of extra high voltage power transmission lines. Both underground and overhead lines are discussed, as well as superconducting and resistive cryogenic lines. Health, safety, and psychological aspects of the electric field, corona, ozone, and acoustic effects of these lines are discussed. New conductors, insulators, mountings, control, and lightning protection for EHV power transmission lines are included. (Contains a minimum of 71 citations and includes a subject term index and title list.)

Not Available

1993-07-01

207

Extra high voltage power transmission. (Latest citations from the NTIS bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning the design, construction, and use of extra high voltage power transmission lines. Both underground and overhead lines are discussed, as well as superconducting and resistive cryogenic lines. Health, safety, and psychological aspects of the electrical field, corona, ozone, and acoustic effects of these lines are discussed. New conductors, insulators, mounting, monitoring, control, and lightning protection of EHV power transmission lines are presented. (Contains a minimum of 82 citations and includes a subject term index and title list.)

Not Available

1993-08-01

208

High voltage insulation performance of cryogenic liquids for superconducting power apparatus  

SciTech Connect

This paper describes high voltage insulation technology of cryogenic liquids for superconducting power apparatus. The insulation of a superconducting transformer is classified into several insulation components. The authors investigate fundamental insulation characteristics peculiar to the superconducting and cryogenic circumstances: area and volume effects on breakdown strength, V-t characteristics, quench-induced dynamic breakdown characteristics and so on. Finally, they systematize the electrical insulation of cryogenic liquids, and propose the flow chart for the practical insulation design of superconducting power apparatus.

Okubo, H.; Hikita, M.; Goshima, H.; Sakakibara, H.; Hayakawa, N. [Nagoya Univ. (Japan)] [Nagoya Univ. (Japan)

1996-07-01

209

30 CFR 56.12071 - Movement or operation of equipment near high-voltage power lines.  

Code of Federal Regulations, 2013 CFR

...false Movement or operation of equipment near high-voltage power lines. 56.12071...12071 Movement or operation of equipment near high-voltage power lines. When equipment must be moved or operated near energized high-voltage powerlines...

2013-07-01

210

Space station electrical power system  

NASA Technical Reports Server (NTRS)

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

Labus, Thomas L.; Cochran, Thomas H.

1987-01-01

211

Low-Power Electric Motors.  

National Technical Information Service (NTIS)

The collection contains materials on the theory and methodology of the designing of low-power electric motors for general industrial use and specialized use. The works published in it discuss the results of investigations of induction and synchronous elec...

G. M. Aron

1972-01-01

212

Solar Thermal Electric Power Systems.  

National Technical Information Service (NTIS)

Results of research to identify cost effective solar thermal electric power systems are given. Parametric performance and cost models were developed for concentrating collector, heat transport, and heat storage subsystems. Dynamic programming methods to s...

1974-01-01

213

Power Processing for Electric Propulsion.  

National Technical Information Service (NTIS)

The inclusion of electric thruster systems in spacecraft design is considered. The propulsion requirements of such spacecraft dictate a wide range of thruster power levels and operational lifetimes, which must be matched by lightweight, efficient, and rel...

R. C. Finke B. G. Herron G. D. Gant

1975-01-01

214

Input Power Characteristics of the Thyristor Variable Voltage Power Conditioner.  

National Technical Information Service (NTIS)

A laboratory study was made of transformer and thyristor voltage control for speed control of a rotary induction motor. The test program consisted of two parts; the first dealing with measurements of the induction motor characteristics and the second with...

J. J. Stickler G. P. Ploetz F. L. Raposa

1973-01-01

215

Wind Electric Power Station.  

National Technical Information Service (NTIS)

A wind power station is described in which the structure on which the rotors are mounted may tilt as wind speed changes so that the rotors leave the vertical plane to anticipate increased wind speeds. The power station may have pulse generators located in...

H. Honnef

1974-01-01

216

Electric Power Annual, 1986.  

National Technical Information Service (NTIS)

Sharply lower petroleum prices in 1986 from 1985 led to increased net generation by petroleum-fired plants and less gas-fired generation. Nuclear-powered generation capability increased in 1986, resulting in increased nuclear-powered net generation. These...

1987-01-01

217

Power quality improvement in stand-alone microgrid including fixed-speed wind farm: Role of dynamic voltage restorer  

Microsoft Academic Search

According to the growth of power generated by wind farms and the increased number of non-linear loads, providing a high quality electrical power, should be considered. This paper is addressed the issue of application and analysis of a Dynamic Voltage Restorer (DVR) to enhance the quality of power flows in a stand-alone microgrid, including wind energy conversion systems and the

Ahmad Jamshidi; Mohammad Moradi Ghahderijani; S. Masoud Barakati

2012-01-01

218

Arizona electric power: our choices  

SciTech Connect

Presentations of three workshops concerned with electric power consumption and use in Arizona are summarized. Addressed were topics such as energy efficient homes and communities; costs of producing electric power; Arizona's regulatory policy; health, safety, and environmental impact of production; and citizen involvement. Arizona's policy issues in electric power are presented, followed by comments of involved citizens. The anticipated benefits that the state would reap from nuclear power are examined in light of safety, environmental, and social risks. The report points out that benefits and costs to the citizens of Arizona from nuclear power generation are not necessarily the same as those borne by the utilities. It is pointed out that alternatives should be considered that are broader than those which the utilities would consider. Scientists are urged to separate their advocacy roles from their scientific roles.

DeBano, A.; McNerney, G.

1981-01-01

219

Using voltage sources as current drivers for electrical impedance tomography  

NASA Astrophysics Data System (ADS)

In multi-frequency electrical impedance tomography (EIT) systems it is much easier to design voltage sources than current sources. It is also at times desirable to operate a voltage driving system as if it were a current driving system. This can be done by adjusting the individual voltage sources until a desired current pattern is obtained. Questions remain regarding the form of the adjustment algorithm and the circumstances under which it will converge. Through simulation and experimentation we have developed a simple algorithm which functions satisfactorily in most practical situations. We have also investigated its theoretical limits for convergence. Simulations showed that convergence is reached in all cases with little (0.1%) or no measurement noise. With moderate noise (0.5%) our algorithm failed to converge in 17 out of 6000 runs, while more significant measurement noise (1%) resulted in convergence in only 7 out of 6000 runs. Experiments with a 16-channel EIT system converged in all cases on volunteer arms, but failed some of the time in saline, with the number of successful runs decreasing with frequency (73.3% at 10 kHz, 71.1% at 125 kHz and 15.5% at 750 kHz), suggesting a possible link to measurement error.

Hartov, Alex; Demidenko, Eugene; Soni, Nirmal; Markova, Mariana; Paulsen, Keith

2002-09-01

220

Technical Development on Partial Discharge Measurement and Electrical Insulation Techniques for Low Voltage Motors Driven by Voltage Inverters  

Microsoft Academic Search

This paper reviews the up-to-date research activities on electrical insulation techniques under repetitive surge voltages with steep wavefront for low voltage inverter-fed motors. Partial discharge (PD) inception, propagation, ageing and breakdown characteristics of magnet wires, including recently developed PD-resistant wires such as nanocomposite enameled wires, are described. PD measurement techniques under the steep-front voltages and IEC activity toward their standardization

Hitoshi Okubo; Naoki Hayakawa; Gian Carlo Montanari

2007-01-01

221

Voltage sag and swell generator for the evaluation of custom power devices  

Microsoft Academic Search

This paper describes a new economical sag\\/swell voltage generator suitable to the evaluations of high power custom power devices such as DVR (Dynamic Voltage Restorer) and DSTATCOM (Distribution Static Compensator). Proposed system was designed to generate the several power quality disturbances in MVA power ratings - sag, swell, under voltage, over voltage and harmonic distortions. The sag and the under

Y. H. Chung; G. H. Kwon; T. B. Park; K. Y. Lim

2003-01-01

222

The physics of electric power systems  

NASA Astrophysics Data System (ADS)

The article describes electric power systems from a physicist's point of view. In contrast to common introductory textbooks on power systems, the emphasis is on the physical design, that is the material selection and the choice of the geometrical shape, of the fundamental components as it follows from the function and serves the main purpose. Why do power system components look the way they look? This is the question addressed in an accessible way. Four fundamental components are needed to make the most elementary power system: overhead transmission lines, transformers, synchronous generators, and circuit breakers. High-voltage overhead lines make efficient long-distance transmission of electric power possible. Transformers step up the power from the generating plant and cascade it down to the final consumption. For their ability to control, independently, real and reactive power, synchronous generators are the most common type of generators. And it is only through the immediate extinction of plasma arcs in circuit breakers that shortcircuit currents can be interrupted and faulty segments of the grid disconnected.

Ohler, C.

2013-06-01

223

Electric power monthly, September 1993  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the US, Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions.

Not Available

1993-09-17

224

Electric power monthly, August 1993  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. The EPM is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the US, Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions.

Not Available

1993-08-13

225

Electrical power system WP04  

Microsoft Academic Search

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

Donald L. Nored

1990-01-01

226

Electrical Analysis of Wind Power  

NSDL National Science Digital Library

For this experiment, students use a DC motor as a generator and various shaped turbine designs to test which design produces the most electrical power. Using a fan to generate the "wind", students attach different blades made of folded paper or card stock to the motor to see how much power is generated.

Peterson, Lina J.

227

Voltages induced on a power distribution line by overhead cloud lightning  

NASA Technical Reports Server (NTRS)

Voltages induced by overhead cloud lightning on a 448 m open circuited power distribution line and the corresponding north-south component of the lightning magnetic field were simultaneously measured at the NASA Kennedy Space Center during the summer of 1986. The incident electric field was calculated from the measured magnetic field. The electric field was then used as an input to the computer program, EMPLIN, that calculated the voltages at the two ends of the power line. EMPLIN models the frequency domain field/power coupling theory found, for example, in Ianoz et al. The direction of the source, which is also one of the inputs to EMPLIN, was crudely determined from a three station time delay technique. The authors found reasonably good agreement between calculated and measured waveforms.

Yacoub, Ziad; Rubinstein, Marcos; Uman, Martin A.; Thomson, Ewen M.; Medelius, Pedro J.

1991-01-01

228

HIL emulation of all-electric UAV power systems  

Microsoft Academic Search

Hardware-in-the-loop (HIL) techniques are used to examine the start-up sequence for an all-electric UAV system powered by a two-spool gas engine with embedded electrical generators on both spools. Start-up begins with the auxiliary power unit charging the high voltage DC bus to enable the high pressure spool switched reluctance starter\\/generator (SRSG) to spin the gas engine to ground idle speed

Rebecca Todd; Andrew J. Forsyth

2009-01-01

229

Electric power monthly, July 1993  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data in this report are presented for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The EIA collected the information in this report to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

Not Available

1993-07-29

230

Electric power monthly, August 1994  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data in this report are presented for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The EIA collected the information in this report to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

Not Available

1994-08-24

231

Electric power monthly, June 1994  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data in this report are presented for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The EIA collected the information in this report to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

Not Available

1994-06-01

232

Electrical power trade-offs  

NASA Technical Reports Server (NTRS)

Electrical power trade studies were initiated in September 1982 supporting the Space Station Systems Definition activity. Responsibility for performing the electrical power trade studies (Power Data Base) was divided between the NASA Centers. Center representatives and their respective subjects are identified in the accompanying chart. The data base material was used to conduct a general storage trade study. When the results appeared to favor the flywheel option, effort was focused on a comparative flywheel investigation wherein a range of flywheel performance and cost possibilities was compared with optimistic projections of competing options.

Giudici, B.

1983-01-01

233

Manned spacecraft electrical power systems  

SciTech Connect

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

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

1987-03-01

234

Static Reactive Power Compensators for High-Voltage Power Systems. Final Report.  

National Technical Information Service (NTIS)

A study conducted to summarize the role of static reactive power compensators for high voltage power system applications is described. This information should be useful to the utility system planning engineer in applying static var systems (SVS) to high v...

1981-01-01

235

Reactive power planning against power system steady state voltage instability  

Microsoft Academic Search

This paper tests a long term VAR planning algorithm, developed earlier to counter steady state voltage instability issues under severe contingencies, on a portion of a large scale system model consisting of 16173 buses representing Eastern interconnection. The planning method is a mixed integer programming (MIP) based optimization algorithm that uses sensitivity information of performance measures with respect to reactive

Venkat Krishnan; Haifeng Liu; James D. McCalley

2008-01-01

236

Power optimization of variable-voltage core-based systems  

Microsoft Academic Search

The growing class of portable systems, such as personal computing and communication devices, has resulted in a new set of system design requirements, mainly characterized by dominant importance of power minimization and design reuse. The energy efficiency of systems-on-a-chip (SOC) could be much improved if one were to vary the supply voltage dynamically at run time. We develop the design

Inki Hong; Darko Kirovski; Gang Qu; Miodrag Potkonjak; Mani B. Srivastava

1999-01-01

237

Reliability improvement methodology for cockpit high-voltage power supplies  

NASA Astrophysics Data System (ADS)

High voltage power supplies (HVPS) have traditionally been among the least reliable components in airborne display electronics. NAVMAT P- 4855-1A, a power supply design manual adopted by the U.S. Navy in 1989, highlighted the source of these problems in industry's failure to apply appropriate methods for high voltage design, development and materials selection. Also, the nature of airborne HVPS is such that MTBF prediction using MIL-HDBK-217 has shown very little correlation to actual field performance. These problems continue today. In recent years, ELDEC has developed a methodology to systematically evaluate and improve the design and long term reliability of high voltage power supplies. This methodology has been successfully applied under a recent Air Force CRT PRAM contract to improve HVPS reliability in AWACS aircraft situation displays. The accelerated testing portion of the methodology has been recommended to the Air Force for adoption as a standard to be used in procurement of future high voltage power supplies. Elements of the methodology are described in this paper.

Chow, Dominic D.; Ardussi, John

1995-06-01

238

Power Losses and Thermal Modeling of A Voltage Source Inverter.  

National Technical Information Service (NTIS)

This thesis presents thermal and power loss models of a three phase IGBT voltage source inverter used in the design of the 625KW fuel cell and reformer demonstration which is a top priority for the Office of Naval Research. The ability to generate thermal...

M. C. Oberdorf

2006-01-01

239

High voltage power supply with integrated photovoltaic cell array  

Microsoft Academic Search

A high-voltage power supply developed for satellite-borne instruments is presented. The principle of operation is described. The structure of the boosting transformer is examined; it consists of a photovoltaic-cell array and a light-emitting-diode array. The transformer efficiency and stability are discussed.

Hitoshi Sekita; Masashi Hashimoto; Tomonao Hayashi; Hiroshi Inagaki; Jun Tajika; M. Kakimoto

1988-01-01

240

Economic generation direction for power system static voltage stability  

Microsoft Academic Search

This paper compares various generation direction methods in static voltage stability study in power systems. A new approach, namely economic generation direction (EGD) approach, is proposed to find the generation direction that minimizes the total operating cost. The proposed method is compared with conventional and the most recent generation direction methods, namely maximum loading margin and optimal generation direction methods,

A. Sode-Yome; N. Mithulananthan; Kwang Y. Lee

2006-01-01

241

Voltage transient study of wind farm under power system fault  

Microsoft Academic Search

To study the voltage transient process of the wind farm when there is fault in the power system on which the wind farm connected, constant speed wind machine with squirrel cage induction generator and variable speed wind machine with double fed induction generator were discussed based on their operation principle and structure. Two kinds of wind farms built by only

Xin-yan Zhang; Wei-qing Wang

2008-01-01

242

Electric power monthly, May 1994  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data in this report are presented for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. This publication provides monthly statistics for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Statistics by company and plant are published on the capability of new generating units, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fossil fuels.

Not Available

1994-05-01

243

Electric power monthly, April 1994  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. This publication provides monthly statistics at the U.S., Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. This April 1994 issue contains 1993 year-end data and data through January 1994.

Not Available

1994-04-01

244

Test results of high-voltage, high-power, solid-state remote power controllers  

NASA Technical Reports Server (NTRS)

This report discusses the results of testing high-voltage, high-power, solid-state remote power controllers (RPC) using RPCs designed and built by John C. Sturman at the Lewis Research Center, Cleveland, Ohio, and utilizing the Autonomously Managed Power Systems (AMPS) breadboard/test facility. These test results are used to determine usefulness of the RPCs for future applications in high-voltage direct-current space power.

Johnson, Yvette Binford; Kapustka, Robert E.

1988-01-01

245

Power Optimization for the MLCA Using Dynamic Voltage Scaling  

Microsoft Academic Search

Dynamic voltage scaling (DVS) is an eectiv e method for re- ducing processor power consumption. We present a compiler- based technique for DVS-based power optimizations of mul- timedia applications in the context of the Multi-Level Com- puting Architecture (MLCA)|a novel architecture for par- allel systems-on-a-chip. Our technique combines dependence analysis of long-running loops with proling information in order to identify

Ivan Matosevic; Tarek S. Abdelrahman; Faraydon Karim; Alain Mellan

2005-01-01

246

Power optimization of variable voltage core-based systems  

Microsoft Academic Search

The growing class of portable systems, such as personal computing and communication devices, has resulted in a new set of system design requirements, mainly characterized by dominant importance of power minimization and design reuse. We develop the design methodology for the low power core-based real-time system-on-chip based on dynamically variable voltage hardware. The key challenge is to develop effective scheduling

Inki Hong; Darko Kirovski; Gang Qu; Miodrag Potkonjak; Mani B. Srivastava

1998-01-01

247

Oceans and electrical power  

Microsoft Academic Search

The first part of this paper focused on the potential energy that could be extracted from salinity an'd thermal differences in the oceans; possibilities of converting marine biomass into an energy source were likewise examined. Closest to implementation are apparently schemes to harness thermal differences and wave energy. Tidal power is already producing energy in France, U.S.S.R. and China. Of

Roger H. Charlier

1982-01-01

248

High-Voltage, Low-Power BNC Feedthrough Terminator  

NASA Technical Reports Server (NTRS)

This innovation is a high-voltage, lowpower BNC (Bayonet Neill-Concelman) feedthrough that enables the user to terminate an instrumentation cable properly while connected to a high voltage, without the use of a voltage divider. This feedthrough is low power, which will not load the source, and will properly terminate the instrumentation cable to the instrumentation, even if the cable impedance is not constant. The Space Shuttle Program had a requirement to measure voltage transients on the orbiter bus through the Ground Lightning Measurement System (GLMS). This measurement has a bandwidth requirement of 1 MHz. The GLMS voltage measurement is connected to the orbiter through a DC panel. The DC panel is connected to the bus through a nonuniform cable that is approximately 75 ft (approximately equal to 23 m) long. A 15-ft (approximately equal to 5-m), 50-ohm triaxial cable is connected between the DC panel and the digitizer. Based on calculations and simulations, cable resonances and reflections due to mismatched impedances of the cable connecting the orbiter bus and the digitizer causes the output not to reflect accurately what is on the bus. A voltage divider at the DC panel, and terminating the 50-ohm cable properly, would eliminate this issue. Due to implementation issues, an alternative design was needed to terminate the cable properly without the use of a voltage divider. Analysis shows how the cable resonances and reflections due to the mismatched impedances of the cable connecting the orbiter bus and the digitizer causes the output not to reflect accurately what is on the bus. After simulating a dampening circuit located at the digitizer, simulations were performed to show how the cable resonances were dampened and the accuracy was improved significantly. Test cables built to verify simulations were accurate. Since the dampening circuit is low power, it can be packaged in a BNC feedthrough.

Bearden, Douglas

2012-01-01

249

Evaluation of high temperature dielectric films for high voltage power electronic applications  

NASA Technical Reports Server (NTRS)

Three high temperature films, polyimide, Teflon perfluoroalkoxy and poly-P-xylene, were evaluated for possible use in high voltage power electronic applications, such as in high energy density capacitors, cables and microelectronic circuits. The dielectric properties, including permittivity and dielectric loss, were obtained in the frequency range of 50 Hz to 100 kHz at temperatures up to 200 C. The dielectric strengths at 60 Hz were determined as a function of temperature to 250 C. Confocal laser microscopy was performed to diagnose for voids and microimperfections within the film structure. The results obtained indicate that all films evaluated are capable of maintaining their high voltage properties, with minimal degradation, at temperatures up to 200 C. However, above 200 C, they lose some of their electrical properties. These films may therefore become viable candidates for high voltage power electronic applications at high temperatures.

Suthar, J. L.; Laghari, J. R.

1992-01-01

250

Nuclear electric power sources  

NASA Technical Reports Server (NTRS)

Measurements on radioactive commercial p-n junction silicon cells show that these units are capable of delivering several hundred microwatts per curie of Am-241 alpha source, indicating their usefulness in such electronic devices as hearing aids, heart pacemakers, electronic watches, delay timers and nuclear dosimeter chargers. It is concluded that the Am-241 sources are superior to the beta sources used previously, because of higher alpha specific ionization and simultaneous production of low energy photons which are easily converted into photoelectrons for additional power.

Singh, J. J.

1978-01-01

251

Managing electrical safety in power utilities  

Microsoft Academic Search

This paper addresses the OSHA, IEEE, and NFPA electrical safety requirements, procedures, and responsibilities for managing electrical safety when working with electric power utility systems and equipment. The three primary hazards of electricity; electrical shock, electrical arc flash, and electrical arc blast will be addressed. The requirements for an Electrical Safety Program, procedures, and personal protective equipment (PPE) will be

Dennis K. Neitzel

2011-01-01

252

Power quality measurements performed on a low-voltage grid equipped with two wind turbines  

Microsoft Academic Search

The power quality of a low-voltage grid with two wind turbines is investigated. Slow voltage variations as well as transients and harmonics are measured and analysed. Furthermore, the spectrum of the power is determined so that the presence of periodic power components can be investigated. Although periodic power fluctuations reaching 10% of the rated power are registered, voltage variations are

T. Thiringer

1996-01-01

253

Single Event Transients in Voltage Regulators for FPGA Power Supply Applications  

NASA Technical Reports Server (NTRS)

As with other bipolar analog devices, voltage regulators are known to be sensitive to single event transients (SET). In typical applications, large output capacitors are used to provide noise immunity. Therefore, since SET amplitude and duration are generally small, they are often of secondary importance due to this capacitance filtering. In low voltage applications, however, even small SET are a concern. Over-voltages may cause destructive conditions. Under-voltages may cause functional interrupts and may also trigger electrical latchup conditions. In addition, internal protection circuits which are affected by load as well as internal thermal effects can also be triggered from heavy ions, causing dropouts or shutdown ranging from milliseconds to seconds. In the case of FPGA power supplies applications, SETS are critical. For example, in the case of Actel FPGA RTAX family, core power supply voltage is 1.5V. Manufacturer specifies an absolute maximum rating of 1.6V and recommended operating conditions between 1.425V and 1.575V. Therefore, according to the manufacturer, any transient of amplitude greater than 75 mV can disrupt normal circuit functions, and overvoltages greater than 100 mV may damage the FPGA. We tested five low dropout voltage regulators for SET sensitivity under a large range of circuit application conditions.

Poivey, Christian; Sanders, Anthony; Kim, Hak; Phan, Anthony; Forney, Jim; LaBel, Kenneth A.; Karsh, Jeremy; Pursley, Scott; Kleyner, Igor; Katz, Richard

2006-01-01

254

Electrical breakdown strength of XLPE cables under combined AC-DC voltage  

Microsoft Academic Search

This paper presents data on electrical breakdown strength of 5 kV XLPE cable under AC voltages, DC voltages, and superimposed AC upon DC voltages. In the latter case, the ratio of the AC to DC voltage components (p=Vac\\/Vdc) was varied between the limits of 0.04voltage should follow

S. Grzybowski; R. L. McMellon

1995-01-01

255

A DSTATCOM controller tuned by Particle Swarm Optimization for an Electric Ship Power System  

Microsoft Academic Search

In an all-electric ship power system, the power quality problems mainly arise due to the pulsed loads, which cause the degradation of the overall system performance. The paper proposes the application of DSTATCOM to improve these power quality problems of an electric ship. DSTATCOM is a shunt compensation device, which regulates the bus voltage by injecting reactive power during the

Pinaki Mitra; Ganesh K. Venayagamoorthy

2008-01-01

256

Electric Power annual 1996: Volume II  

SciTech Connect

This document presents a summary of electric power industry statistics. Data are included on electric utility retail sales of electricity, revenues, environmental information, power transactions, emissions, and demand-side management.

NONE

1997-12-01

257

Mini-Scale Power Distribution Network Feeding Trapezoidal-Wave Voltages to Power Electronic Loads with Diode Rectifiers  

Microsoft Academic Search

This paper proposes a novel three-phase power distribution system feeding trapezoidal voltages to various power electronic loads with diode rectifier front-ends. The network distributes trapezoidal voltages generated by synchronous superposition of wave-shaping voltages onto sinusoidal voltages available from a utility power grid. The power distribution by the trapezoidal voltages allows reducing harmonics of the line currents without electronic switching devices

Toshihiko Noguchi; Masaru Imoto; Yoshikazu Sato

2004-01-01

258

Electric Power Monthly, July 1990  

SciTech Connect

The Electric Power Monthly (EPM) is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, and average revenue per kilowatthour of electricity sold. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost in fuel. Quantity, quality, and cost of fuel data lag the net generation, fuel consumption, fuel stocks, electricity sales, and average revenue per kilowatthour data by 1 month. This difference in reporting appears in the national, Census division, and State level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison. 12 refs., 4 figs., 48 tabs.

Not Available

1990-10-12

259

Low-Voltage Low-Power Opamp Based Amplifiers  

Microsoft Academic Search

\\u000a Amplifiers operating under low-voltage and low-power conditions are strongly limited in dynamic range and bandwidth. The maximum\\u000a dynamic range is limited by the supply power and the thermal noise power in resistors. To obtain the maximum, input and output\\u000a stages should be able to process signals from rail to rail. Several rail-to-rail input stages and rail-to-rail output stages\\u000a biased in

Johan H. Huijsing; KLAAS-JAN DE LANGEN; Ron Hogervorst; Ruud G. H. Eschauzier

260

Voltage and power relationships in lithium-containing solar cells.  

NASA Technical Reports Server (NTRS)

Photovoltaic characteristics have been measured on a large number of crucible-grown lithium-containing solar cells irradiated by 1-MeV electrons to fluences ranging from 3 x 10 to the 13th power to 3 x 10 to the 15th power electrons per sq cm. These measurements have established empirical relationships between cell photovoltaic parameters and lithium donor density gradient. Short-circuit current and maximum power measured immediately after irradiation decrease logarithmically with lithium gradient. Open-circuit voltage increases logarithmically with lithium gradient both immediately after irradiation and after recovery, the degree of recovery being strongly gradient-dependent at high fluence. As a result, the maximum power and the power at 0.43 V after recovery from 3 x 10 to the 15th power electrons per sq cm increase with increasing lithium gradient.

Faith, T. J.

1972-01-01

261

Power electronics interfaces for low voltage distribution generation — EMC issues  

Microsoft Academic Search

In recent years there is observed an intensive growth of activities in matter of bidirectional electrical energy distribution systems. In situation of fast industrial progress the Electrical Power System (EPS) has to be developed to meet energy demand. This development in accordance to new environmental requirements (1) should be managed very cleaver. Because of these the participation of small renewable

Robert Smolenski; Marcin Jarnut; Grzegorz Benysek; Adam Kempski

2011-01-01

262

Software control program for 25 kW breadboard testing. [spacecraft power supplies; high voltage batteries  

NASA Technical Reports Server (NTRS)

A data acquisition software program developed to operate in conjunction with the automated control system of the 25 kW PM Electric Power System Breadboard Test facility is described. The proram provides limited interactive control of the breadboard test while acquiring data and monitoring parameters, allowing unattended continuous operation. The breadboard test facility has two positions for operating separate configurations. The main variable in each test setup is the high voltage Ni-Cd battery.

Pajak, J. A.

1981-01-01

263

Wavelet based method for fault detection in Medium Voltage DC shipboard power systems  

Microsoft Academic Search

This paper proposes a wavelet transform (WT) based multi-resolution analysis (MRA) method to obtain the features of different fault types in Medium Voltage DC (MVDC) shipboard power systems. DC topology is under consideration for future all-electric ships. One of the new challenges related to this architecture is fault detection. WT-based MRA method, as well as its properties, are studied and

Weilin Li; Min Luo; Antonello Monti; Ferdinanda Ponci

2012-01-01

264

Development of a commercially applicable prototypes for on-line monitoring of partial discharges and pollution effects on safety of high voltage power equipment  

Microsoft Academic Search

Electric utilities have been facing major concerns related to the ageing and deterioration of high voltage power equipment in service. With advancing technologies in the field of sensors and data acquisition systems it is feasible to develop and implement on-line condition monitoring systems for high voltage equipment. In the Department of Electrical Engineering, RMIT University, major research projects are in

S. Shihab; T. Taskin; J. Grzan

1998-01-01

265

Power Usage and Electrical Circuit Analysis for Electric Arc Furnaces  

Microsoft Academic Search

Power usage in ultrahigh-powered electric arc furnaces requires considerably more investigation into system parameters, furnace secondary circuit analysis, and operating characteristics than previously given to normal powered electric arc furnaces. The power input must be analyzed from the infinite electric utility bus to the arc at the electrode. All interested parties must participate in the analysis to assure a mutual

J. J. Trageser

1980-01-01

266

Advanced aircraft electric power system  

SciTech Connect

The role of electric energy in both military and commercial aircraft increases in importance with every advancement in airframe performance and avionic technology. Microcircuits and volatile memories impact power continuity and quality, digital flight control and stability augmentation require high reliability. This paper presents the system concept, hardware development and status of the Navy program.

Segrest, J.D.

1981-01-01

267

Pulsed power for electric guns  

Microsoft Academic Search

Pulsed power requirements for electric guns are described and preferred technologies for energy storage and pulse compression are discussed. Primary approaches are rotating machines and capacitor based, pulse-forming networks, but alternative technologies that may offer some operational benefits are also discussed. These include linear magnetic flux compressors, cryogenically cooled, high-temperature superconducting inductors, novel dielectrics for energy storage, and pulsed magnetohydrodynamic

Ian R. McNab

1997-01-01

268

Real Time Voltage and Current Phase Shift Analyzer for Power Saving Applications  

PubMed Central

Nowadays, high importance is given to low energy devices (such as refrigerators, deep-freezers, washing machines, pumps, etc.) that are able to produce reactive power in power lines which can be optimized (reduced). Reactive power is the main component which overloads power lines and brings excessive thermal stress to conductors. If the reactive power is optimized, it can significantly lower the electricity consumption (from 10 to 30%—varies between countries). This paper will examine and discuss the development of a measuring device for analyzing reactive power. However, the main problem is the precise real time measurement of the input and output voltage and current. Such quality measurement is needed to allow adequate action intervention (feedback which reduces or fully compensates reactive power). Several other issues, such as the accuracy and measurement speed, must be examined while designing this device. The price and the size of the final product need to remain low as they are the two important parameters of this solution.

Krejcar, Ondrej; Frischer, Robert

2012-01-01

269

Influence of electric power distribution system design on harmonic propagation  

Microsoft Academic Search

The impact of the design parameters of electric power distribution systems on the propagation of harmonic distortion is investigated. This conceptual study is based on simulations on a generalized distribution system model, and leads to an increased insight in the mechanisms of the generation and propagation of voltage distortion. Moreover, analytical expressions are presented that predict the impact of changing

J. A. Ghijselen; W. A. Ryckaert; J. A. Melkebeek

2004-01-01

270

A low power sub-1 V CMOS voltage reference  

Microsoft Academic Search

This work describes the circuit which generates a stable voltage of 466.5 mV for 1.8 V power supply in 0.18 mum technology. Circuit uses MOSFETs in linear region and in subthreshold region to generate PTAT and CTAT respectively intended to replace resistor and BJT. The temperature coefficient of circuit is 28.4 ppm\\/degC in the range of -20 to +120degC. The

Sameer Somvanshi; Santhosh Kasavajjala

2008-01-01

271

Lyapunov stability of multimachine power systems considering the voltage regulator  

Microsoft Academic Search

A new decomposition–aggregation approach is developed, in the paper, to perform transient stability analysis of an N-machine power system. Considering the generator flux decay effect, non-uniform mechanical damping, transfer conductances and the automatic voltage regulator action, the system mathematical model is derived. It is obtained a system aggregation (square) matrix of the order (N?1)\\/2, stability of this matrix implies asymptotic

H. Shaaban

2002-01-01

272

Electrical power generation and distribution system  

Microsoft Academic Search

Problems associated with moving fuel from remote sources to large centralized power generation plants are avoided with an economical system for collecting power from small stations located near the scattered, remote fuel sites. To avoid a need for many massive, costly transformers, a plurality of relatively low voltage generating stations are connected in series to cumulatively produce the high voltage

Jeppson

1977-01-01

273

Electric power monthly, October 1993  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data in this report are presented for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The EIA collected the information in this report to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended. This publication provides monthly statistics at the US, Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. Statistics by company and plant are published in the EPM on the capability of new generating units, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fossil fuels.

Not Available

1993-10-20

274

Electric power monthly, January 1994  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly electricity statistics. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data in this report are presented for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The EIA collected the information in this report to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended. This publication provides monthly statistics at the US Census division, and State levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. Statistics by company and plant are published in the EPM on the capability of new generating units, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fossil fuels.

Not Available

1994-01-26

275

Strategy of reactive power and voltage control in large wind farms integrated region  

Microsoft Academic Search

In this paper, a voltage control strategy of a large wind farms integrated region is proposed. The strategy regulates the network voltage by coordinating the reactive power among wind farms. When the voltage control point of the region is selected, then the steady state voltage without disturbance is selected as the control objective. Firstly, the reactive power\\/loss sensitivity is used

X. R. Zhu; Y. Wang; C. Fu

2010-01-01

276

Electric power annual 1995. Volume II  

SciTech Connect

This document summarizes pertinent statistics on various aspects of the U.S. electric power industry for the year and includes a graphic presentation. Data is included on electric utility retail sales and revenues, financial statistics, environmental statistics of electric utilities, demand-side management, electric power transactions, and non-utility power producers.

NONE

1996-12-01

277

Inspira™ — an enabling battery technology for high voltage automotive electrical systems  

Microsoft Academic Search

Vehicle manufacturers worldwide are recognizing the need to elevate the electrical system voltage on their product from the present standard of 12 V to a significantly higher, yet safe, voltage. One of the major challenges emerging from the move to higher voltages is the size, weight, volume, cost and complexity of the battery required to support such a system. Inspira™,

Robert G Gruenstern; John R Pierson

2000-01-01

278

Module Two: Voltage; Basic Electricity and Electronics Individualized Learning System.  

ERIC Educational Resources Information Center

In this module the student will study and learn what voltage is, how it is generated, what AC (alternating current) and DC (direct current) are and why both kinds are needed, and how to measure voltages. The module is divided into six lessons: EMF (electromotive force) from chemical action, magnetism, electromagnetic induction, AC voltage, the…

Bureau of Naval Personnel, Washington, DC.

279

Voltage endurance test facility for electric generator stator coils  

Microsoft Academic Search

The development of new coil designs with the use of updated materials and\\/or processes requires voltage endurance testing as one of the tests to verify the new coil design. From established voltage endurance curves, a new insulation system can be evaluated against accepted coil designs. An expanded voltage endurance test lab has been developed which has the capabilities for testing

F. T. Emery; R. F. Weddleton

1993-01-01

280

Unilateral sensorineural hearing loss and facial nerve paralysis associated with low-voltage electrical shock.  

PubMed

Electrical injuries can occur as a result of contact with low- or high-voltage electricity. Low-voltage injuries are more common, as they usually occur in the home, but reports in the literature are few. After exposure to electric current, almost every organ system in the body is affected. The severity of an injury depends on many factors, including the type of current, the duration of exposure, and the resistance of the tissue involved. Reported cases of hearing loss and facial nerve paralysis associated with low-voltage electrical shock are rare, and minimal information is available about this circumstance. In this article, the author describes a case of low-voltage electrical shock in a 20-year-old man. To the best of the author's knowledge, this is the first report in the literature of a resolution of unilateral sensorineural hearing loss and facial nerve paralysis caused by a low-voltage electrical shock. PMID:24526477

Ozkiris, Mahmut

2014-02-01

281

Electrical biasing and voltage contrast imaging in a focused ion beam system.  

National Technical Information Service (NTIS)

We present two new techniques that enhance conventional focused ion beam (FIB) system capabilities for integrated circuit (IC) analysis: in situ electrical biasing and voltage contrast imaging. We have used in situ electrical biasing to enable a number of...

A. N. Campbell J. M. Soden J. L. Rife R. G. Lee

1995-01-01

282

Manned spacecraft electrical power systems  

NASA Technical Reports Server (NTRS)

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

Simon, William E.; Nored, Donald L.

1987-01-01

283

Development of power distribution cabinet for higher-voltage direct-current power feeding system  

Microsoft Academic Search

Reducing the feeding loss of information and communications technology equipment, such as servers and routers, is very effective for reducing the total power consumption in data centers and telecommunication buildings. In this paper, the structure and function of a higher-voltage direct-current (HVDC) power feeding system prototype is presented. This system was developed to reduce power delivery and conversion losses by

Tadatoshi Babasaki; Toshimitsu Tanaka; Kaoru Asakura; Yousuke Nozaki; Fujio Kurokawa

2010-01-01

284

Electric Power Monthly, June 1990  

SciTech Connect

The EPM is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, electricity sales, and average revenue per kilowatthour of electricity sold. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel. Quantity, quality, and cost of fuel data lag the net generation, fuel consumption, fuel stocks, electricity sales, and average revenue per kilowatthour data by 1 month. This difference in reporting appears in the national, Census division, and State level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison. 40 tabs.

Not Available

1990-09-13

285

Simulating voltage collapse dynamics for power systems with constant power load models  

Microsoft Academic Search

Electromechanical transients are studied using transient stability simulators with differential-algebraic equation (DAE) models employing phasor network variables. While these simulators can follow the electromechanical transients (e.g., voltage and power swings) due to large disturbances with loads modeled as constant impedance, they may fail to converge under voltage collapse conditions for systems with constant power load models. This non-convergence has been

S. G. Abhyankar; A. J. Flueck

2008-01-01

286

Power processing for electric propulsion  

NASA Technical Reports Server (NTRS)

The inclusion of electric thruster systems in spacecraft design is considered. The propulsion requirements of such spacecraft dictate a wide range of thruster power levels and operational lifetimes, which must be matched by lightweight, efficient, and reliable thruster power processing systems. Electron bombardment ion thruster requirements are presented, and the performance characteristics of present power processing systems are reviewed. Design philosophies and alternatives in areas such as inverter type, arc protection, and control methods are discussed along with future performance potentials for meeting goals in the areas of power process or weight (10 kg/kW), efficiency (approaching 92 percent), reliability (0.96 for 15,000 hr), and thermal control capability (0.3 to 5 AU).

Finke, R. C.; Herron, B. G.; Gant, G. D.

1975-01-01

287

Voltage and Reactive Power Control Taking into Account of Economy and Security by using Tabu Search  

NASA Astrophysics Data System (ADS)

Due to deregulation of electric power market, the several power transactions and the distributed generators will increase year by year. The power flow in power system will vary increasingly more complex and more uncertain by them. So it is difficult for Voltage and reactive power(Q) Control (VQC) to sustain the adequate voltages in the power system. On the other hand, the economy and security are requested for power system operation and control under the competitive environment. The optimization algorithm is effective to satisfy these trade-off problem. The optimization of VQC traces the combinational optimization problem with shunt devices, transformer tap and generator terminal voltage. Tabu Search (TS), which is one of meta-heuristic approaches, is suitable for the optimization problem of VQC. Because it is able to deal with the discrete variables such as shunt devices easily and it needs few tuning parameters. In this paper, in order to realize flexible VQC which responds to the uncertain power flow with competitive environment, we propose the optimization of VQC with TS algorithm taking into account of both economy and security. The security is considered as the minimization of generator reactive outputs and transformer tap positions difference from the neutral. Moreover, the novel neighborhood condition setting focused on the control interference between voltage control equipments is applied to minimizing the objective function. It is confirmed by several numerical simulations using IEEE 14 and 57 bus system that the proposed scheme is able to ensure the security and to find the useful optimal solution efficiently.

Nakachi, Yoshiki; Kato, Atsushi; Ukai, Hiroyuki

288

Static reactive power compensators for high-voltage power systems. Final report  

SciTech Connect

A study conducted to summarize the role of static reactive power compensators for high voltage power system applications is described. This information should be useful to the utility system planning engineer in applying static var systems (SVS) to high voltage as (HVAC) systems. The static var system is defined as a form of reactive power compensator. The general need for reactive power compensation in HVAC systems is discussed, and the static var system is compared to other devices utilized to provide reactive power compensation. Examples are presented of applying SVS for specific functions, such as the prevention of voltage collapse. The operating principles of commercially available SVS's are discussed in detail. The perormance and active power loss characteristics of SVS types are compared.

Not Available

1981-04-01

289

Nanosatellite electrical power system development  

NASA Astrophysics Data System (ADS)

Nanosatellites have the potential to carry out the complex work of today's larger satellites at a fraction of the cost. Their small designs drastically reduce launch costs and allow many research projects and technology demonstration missions to be flown. The development of small satellites has created a need for smaller, lightweight electrical power systems (EPS) without compromising the power capacity. This thesis focuses on the electrical power system of the YUsend-1 mission. The work carried out in designing and developing the EPS for the YUsend mission utilizing commercial technologies is outlined. Mission modes are developed and a power budget is assigned for the different subsystems setting a baseline for how much power is needed. Different battery chemistries are analyzed in order to find a type that would suit the needs of the YUsend program. Commercially available batteries are put through space environment testing and the results are presented. The fabrication, testing, and space qualification results of solar panels using Triangular Advanced Solar Cells (TASCs) are also presented. Lastly the layout for the distribution board is developed.

Navarathinam, Nimal

290

Buried Oxide Densification for Low Power, Low Voltage CMOS Applications  

NASA Technical Reports Server (NTRS)

Special technology and circuit architecture are of growing interest for implementation of circuits which operate at low supply voltages and consume low power levels without sacrificing performance[1]. Use of thin buried oxide SOI substrates is a primary approach to simultaneously achieve these goals. A significant aspect regarding SIMOX SOI for low voltage, low power applications is the reliability and performance of the thin buried oxide. In addition, when subjected to high total dose irradiation, the silicon islands within the BOX layer of SIMOX can store charges and significantly effect the back channel threshold voltages of devices. Thus, elimination of the islands within the buried oxide (BOX) layer is preferred in order to prevent leakage through these conductive islands and charge build-up within the buried oxide layer. A differential (2-step) ramp rate as applied to full and 100 nm BOX SIMOX was previously reported to play a significant role in the stoichiometry and island formation within the buried layer[2]. This paper focus is on the properties of a thin (120nm) buried oxide as a function of the anneal ramp rate and the temperature of anneal. In this research, we have found an improvement in the buried oxide stoichiometry with the use of a slower, singular ramp rate for specified thin buried oxides, with slower ramp rates and higher temperatures of anneal suggested for reducing the presence of Si islands within the BOX layer.

Allen, L. P.; Anc, M. J.; Dolan, B.; Jiao, J.; Guss, B.; Seraphin, S.; Liu, S. T.; Jenkins, W.

1998-01-01

291

Computer Analyses and Practical Solution of Mobile Electrical Power Sources with VSCF Technology  

Microsoft Academic Search

This paper brings some practical results of research devoted to the new generation of mobile electrical power sources, based on the VSCF technology (Variable Speed - Constant Frequency). In this new generation of mobile electrical power sources the driving motor and generator speed is optimally controlled in accordance with the load power thus decreasing the fuel consumption. The output voltage

JAN LEUCHTER; OTAKAR KURKA

292

The control of high-speed variable-reluctance generators in electric power systems  

Microsoft Academic Search

This work studies the control of a direct-current (DC) electric power system that is sourced by a variable-reluctance generator. The power system includes the generator and its switching inverter, a filtering capacitor, a distribution network and an electrical load. The network comprises a series resistor and inductor, while the load comprises a parallel resistor, capacitor and power sink. The voltage

D. E. Cameron; J. H. Lang

1993-01-01

293

The control of high-speed variable-reluctance generators in electric power systems  

Microsoft Academic Search

The control of a direct-current electric power system that is sourced by a variable-reluctance generator (VRG) is studied. The power system includes the generator and its switching inverter, a filtering capacitor, a distribution network, and an electrical load. The network comprises a series resistor and inductor, while the load comprises a parallel resistor, capacitor, and power sink. The voltage at

D. E. Cameron; J. H. Lang

1992-01-01

294

EMTP based stability analysis of Space Station Electric Power System in a test bed environment  

Microsoft Academic Search

The Space Station Freedom Electric Power System (EPS) will convert solar energy into electric energy and distribute the same using an 'all dc', Power Management and Distribution (PMAD) System. Power conditioning devices (dc to dc converters) are needed to interconnect parts of this system operating at different nominal voltage levels. Operation of such devices could generate under damped oscillations (instability)

Narayan V. Dravid; Thomas J. Kacpura; Andrew M. O'Connor

1992-01-01

295

Effect of Electrical-Utility-System Voltage Harmonics on Induction Motors.  

National Technical Information Service (NTIS)

Distortion of the electrical utility system voltage waveform can result in damage to or malfunction of user electrical equipment. An experiment was carried out to determine the effect of utility voltage harmonics on the temperature rise of single-phase in...

N. E. Rasmussen

1981-01-01

296

A Reduced-Part, Triple-Voltage DC–DC Converter for EV\\/HEV Power Management  

Microsoft Academic Search

Electrical power systems in future hybrid and fuel cell vehicles may consist of three voltage nets: 14 V, 42 V, and high voltage (>200 V) buses. A soft-switched, bidirectional dc-dc converter that uses only four switches was proposed for interconnecting the three nets. This paper presents a reduced-part dc-dc converter, which decreases the converter cost while retaining all the favorable

Gui-Jia Su; Lixin Tang

2009-01-01

297

Effect of electrical-utility-system voltage harmonics on induction motors  

NASA Astrophysics Data System (ADS)

Distortion of the electrical utility system voltage waveform can result in damage to or malfunction of user electrical equipment. An experiment was carried out to determine the effect of utility voltage harmonics on the temperature rise of single phase induction motors. The results suggest that utility voltage harmonics do not significantly affect the operating temperature of a single phase induction motor until the amplitudes of the harmonics are much larger than the amplitudes currently present in the U.S. utility system.

Rasmussen, N. E.

1981-03-01

298

Power Sales to Electric Utilities  

SciTech Connect

The Public Utilities Regulatory Policies Act (PURPA) of 1979 requires that electrical utilities interconnect with qualifying facilities and purchase electricity at a rate based upon their full avoided costs (i.e., costs of providing both capacity and energy). Qualifying facilities (QF) include solar or geothermal electric units, hydropower, municipal solid waste or biomass-fired power plants, and cogeneration projects that satisfy maximum size, fuel use, ownership, location, and/or efficiency criteria. In Washington State, neither standard power purchase prices based upon a proxy ''avoided plant'', standard contracts, or a standard offer process have been used. Instead, a variety of power purchase contracts have been negotiated by developers of qualifying facilities with investor-owned utilities, public utility districts, and municipally-owned and operated utilities. With a hydro-based system, benefits associated with resource acquisition are determined in large part by how compatible the resource is with a utility's existing generation mix. Power purchase rates are negotiated and vary according to firm energy production, guarantees, ability to schedule maintenance or downtime, rights of refusal, power plant purchase options, project start date and length of contract; front-loading or levelization provisions; and the ability of the project to provide ''demonstrated'' capacity. Legislation was also enacted which allows PURPA to work effectively. Initial laws established ownership rights and provided irrigation districts, PUDs, and municipalities with expanded enabling powers. Financial processes were streamlined and, in some cases, simplified. Finally, laws were passed which are designed to ensure that development proceeds in an environmentally acceptable manner. In retrospect, PURPA has worked well within Washington. In the state of Washington, 20 small-scale hydroelectric projects with a combined generating capacity of 77 MW, 3 solid waste-to-energy facilities with 55 MW of electrical output, 4 cogeneration projects with 34.5 MW of generating capability, and 4 wastewater treatment facility digester gas-to-energy projects with 5 MW of electrical production have come on-line (or are in the final stages of construction) since the passage of PURPA. These numbers represent only a small portion of Washington's untapped and underutilized cogeneration and renewable resource generating potentials. [DJE-2005

None

1989-02-01

299

TEP Power Partners Project [Tucson Electric Power  

SciTech Connect

The Arizona Governor’s Office of Energy Policy, in partnership with Tucson Electric Power (TEP), Tendril, and Next Phase Energy (NPE), formed the TEP Power Partners pilot project to demonstrate how residential customers could access their energy usage data and third party applications using data obtained from an Automatic Meter Reading (AMR) network. The project applied for and was awarded a Smart Grid Data Access grant through the U.S. Department of Energy. The project participants’ goal for Phase I is to actively engage 1,700 residential customers to demonstrate sustained participation, reduction in energy usage (kWh) and cost ($), and measure related aspects of customer satisfaction. This Demonstration report presents a summary of the findings, effectiveness, and customer satisfaction with the 15-month TEP Power Partners pilot project. The objective of the program is to provide residential customers with energy consumption data from AMR metering and empower these participants to better manage their electricity use. The pilot recruitment goals included migrating 700 existing customers from the completed Power Partners Demand Response Load Control Project (DRLC), and enrolling 1,000 new participants. Upon conclusion of the project on November 19, 2013: ? 1,390 Home Area Networks (HANs) were registered. ? 797 new participants installed a HAN. ? Survey respondents’ are satisfied with the program and found value with a variety of specific program components. ? Survey respondents report feeling greater control over their energy usage and report taking energy savings actions in their homes after participating in the program. ? On average, 43 % of the participants returned to the web portal monthly and 15% returned weekly. ? An impact evaluation was completed by Opinion Dynamics and found average participant savings for the treatment period1 to be 2.3% of their household use during this period.2 In total, the program saved 163 MWh in the treatment period of 2013.

None

2013-11-19

300

Satellite control of electric power distribution  

NASA Technical Reports Server (NTRS)

An L-band frequencies satellite link providing the medium for direct control of electrical loads at individual customer sites from remote central locations is described. All loads supplied under interruptible-service contracts are likely condidates for such control, and they can be cycled or switched off to reduce system loads. For every kW of load eliminated or deferred to off-peak hours, the power company reduces its need for additional generating capacity. In addition, the satellite could switch meter registers so that their readings automatically reflected the time of consumption. The system would perform load-shedding operations during emergencies, disconnecting large blocks of load according to predetermined priorities. Among the distribution operations conducted by the satellite in real time would be: load reconfiguration, voltage regulation, fault isolation, and capacitor and feeder load control.

Bergen, L.

1981-01-01

301

Seismic reliability of electrical power transmission systems  

Microsoft Academic Search

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

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

1996-01-01

302

Controllability and diagnosis in electric power systems  

Microsoft Academic Search

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

Mingguo Hong

1998-01-01

303

Contribution History of Research Institutes to Electric Power Industry in Japan  

NASA Astrophysics Data System (ADS)

After reorganization of power industry in 1951, power system of Japan was remarkably expanded. To cope with this, R&D in vast area was conducted in the academy, MITI, electric power companies, manufactures, and research institutes. This paper generally describes the technical contents that the three research institutes, namely Electrotechnical Laboratory (ETL), High Voltage Power Laboratory (HVPL), and Central Research Institute of Electric Power Industry (CRIEPI), have contributed to the development of power transmission technology after the war.

Taniguchi, Haruhito; Shindo, Takatoshi

304

Voltage grading model for high voltage electric generator stator coil end turn regions  

Microsoft Academic Search

Semiconductive tapes are applied to the end turn region of high voltage stator coils to reduce corona discharge at the slot exit region. The nonlinear, stress grading tapes are used to even out the voltage stress resulting in a more even distribution which also reduces the maximum stress level. To be able to optimize the stress grading capabilities of the

F. T. Emery; D. C. Johnson

1998-01-01

305

Design of a high voltage input - output ratio dc-dc converter dedicated to small power fuel cell systems  

NASA Astrophysics Data System (ADS)

Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andújar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells are low voltage and high current electric generators. On the contrary, electric loads are commonly designed for small voltage swing and a high V/I ratio in order to minimize Joule losses. Therefore, electric loads supplied by fuel cells are typically fed by means of an intermediate power voltage regulator. The specifications of such a power converter are to be able to step up the input voltage with a high ratio (a ratio of 10 is a classic situation) and also to work with an excellent efficiency (in order to minimize its size, its weight and its losses) [A. Shahin, B. Huang, J.P. Martin, S. Pierfederici, B. Davat, Energy Conv. Manag. 51, 56 (2010)]. This paper deals with the design of this essential ancillary device. It intends to bring out the best structure for fulfilling this function. Several dc-dc converters with large voltage step-up ratios are introduced. A topology based on a coupled inductor or tapped inductor is closely studied. A detailed modelling is performed with the purpose of providing designing rules. This model is validated with both simulation and implementation. The experimental prototype is based on the following specifications: the fuel cell output voltage ranges from a 50 V open-voltage to a 25 V rated voltage while the load requires a constant 250 V voltage. The studied coupled inductor converter is compared with a classic boost converter commonly used in this voltage elevating application. Even though the voltage regulator faces severe FC specifications, the measured efficiency reaches 96% at the rated power whereas conventional boost efficiency barely achieves 91.5% in the same operating conditions.

Béthoux, O.; Cathelin, J.

2010-12-01

306

Power processing for electric propulsion  

NASA Technical Reports Server (NTRS)

The potential of achieving up to 30 per cent more spacecraft payload or 50 per cent more useful operating life by the use of electric propulsion in place of conventional cold gas or hydrazine systems in science, communications, and earth applications spacecraft is a compelling reason to consider the inclusion of electric thruster systems in new spacecraft design. The propulsion requirements of such spacecraft dictate a wide range of thruster power levels and operational lifetimes, which must be matched by lightweight, efficient, and reliable thruster power processing systems. This paper will present electron bombardment ion thruster requirements; review the performance characteristics of present power processing systems; discuss design philosophies and alternatives in areas such as inverter type, arc protection, and control methods; and project future performance potentials for meeting goals in the areas of power processor weight (10 kg/kW), efficiency (approaching 92 per cent), reliability (0.96 for 15,000 hr), and thermal control capability (0.3 to 5 AU).

Finke, R. C.; Herron, B. G.; Gant, G. D.

1975-01-01

307

Electric power distribution and load transfer system  

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

308

Electric power distribution and load transfer system  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

309

Digital voltage\\/current control of a high voltage output LCC resonant converter based power supply for capacitor charging  

Microsoft Academic Search

A control scheme is presented for a high voltage output power supply based on an LCC resonant converter which exploits the flexibility of digital methods to attain high performance with simple algorithms. The control scheme uses voltage and current control operating modes; the interaction of these modes is analytically investigated. Optimally fast capacitor charging is attained by charging up using

Chester Ditmanson; H. Guldner; Frank Gleisberg; Martin Rentzsch

2009-01-01

310

Electric vehicles as a new power source for electric utilities  

Microsoft Academic Search

Electric-drive vehicles, whether fueled by batteries or by liquid or gaseous fuels generating electricity on-board, will have value to electric utilities as power resources. The power capacity of the current internal combustion passenger vehicle fleet is enormous and under-utilized. In the United States, for example, the vehicle fleet has over 10 times the mechanical power of all current U.S. electrical

Steven E. Letendre

1997-01-01

311

FBG based intelligent sensors and structure for electrical power system  

NASA Astrophysics Data System (ADS)

Fiber Bragg grating (FBG) sensors are of particular interest for applications in the high voltage environments of electric power industry. The study on the parameter examination and health monitor of the electric power apparatus has great social significance and economic benefits. In this paper, the electric field or voltage sensor is constructed by using the electrostriction material PZT combined with the FBG, while the magnetic field or current sensor is based on the giant magnetostriction material (GMM). The characteristics of FBG strain, the relationship between the electrostriction displacement of piezoelectric ceramic (PZT) material and the excitation voltage, relationship of the magnetostriction displacement with excitation current, are analyzed respectively. The designed intelligent electrostrictive and magnetostrictive sensors are both with temperature compensation. In each sensor, two FBG's are bonded in perpendicular to each other that the electrostictive or magnetostrictive effects on the two gratings are added together, while the temperature effects are cancelled out. These electrical parameter sensors can be widely used for fault diagnosis in electrical substation. The development trend and applications of FBG sensors for power system are discussed.

Yao, Yuan; Yi, Benshun; Xiao, Jinsheng; Li, Zhaohui

2007-10-01

312

Application of Superconducting Power Cables to DC Electric Railway Systems  

NASA Astrophysics Data System (ADS)

For novel design and efficient operation of next-generation DC electric railway systems, especially for their substantial energy saving, we have studied the feasibility of applying superconducting power cables to them. In this paper it is assumed that a superconducting power cable is applied to connect substations supplying electric power to trains. An analysis model line was described by an electric circuit, which was analyzed with MATLAB-Simulink. From the calculated voltages and currents of the circuit, the regenerative brake and the energy losses were estimated. In addition, assuming the heat loads of superconducting power cables and the cryogenic efficiency, the energy saving of the total system was evaluated. The results show that the introduction of superconducting power cables could achieve the improved use of regenerative brake, the loss reduction, the decreased number of substations, the reduced maintenance, etc.

Ohsaki, Hiroyuki; Lv, Zhen; Sekino, Masaki; Tomita, Masaru

313

Application of Newton's optimal power flow in voltage/reactive power control  

SciTech Connect

This paper considers an application of Newton's optimal power flow to the solution of the secondary voltage/reactive power control in transmission networks. An efficient computer program based on the latest achievements in the sparse matrix/vector techniques has been developed for this purpose. It is characterized by good robustness, accuracy and speed. A combined objective function appropriate for various system load levels with suitable constraints, for treatment of the power system security and economy is also proposed. For the real-time voltage/reactive power control, a suboptimal power flow procedure has been derived by using the reduced set of control variables. This procedure is based on the sensitivity theory applied to the determination of zones for the secondary voltage/reactive power control and corresponding reduced set of regulating sources, whose reactive outputs represent control variables in the optimal power flow program. As a result, the optimal power flow program output becomes a schedule to be used by operators in the process of the real-time voltage/reactive power control in both normal and emergency operating states.

Bjelogrlic, M.; Babic, B.S. (Electric Power Board of Serbia, Belgrade (YU)); Calovic, M.S. (Dept. of Electrical Engineering, University of Belgrade, Belgrade (YU)); Ristanovic, P. (Institute Nikola Tesla, Belgrade (YU))

1990-11-01

314

High voltage electrical burn injuries in teenage children: case studies with similarities (an indian perspective)  

PubMed Central

Summary From 1992 to 2012, a total of 911 paediatric burns were admitted and treated at Kanchi Kamakoti Childs Trust Hospital Intensive Burn Care Unit, of these 28 children had suffered electrical injuries and burns. 7 teenagers suffered high voltage electrical burn injuries: 2 were involved in train accidents which caused fatal electrical injuries, and 5 had electrical burn injuries caused by similar types of accidents, requiring Paediatric Intensive Care Unit (PICU) care, repeated surgeries and extensive rehabilitation. A common factor among these latter 5 patients was that they were injured by overhead high electrical voltage cables. Their management was labour intensive and highly costly. In this report, the type of accident, the electrical voltage that produced burns and the treatment details are elaborated. Findings included similarities in age and type of accident, and failure to implement safety procedures and apply standard norms of high voltage transmission feeder lines.

Mathangi Ramakrishnan, K.; Babu, M.; Mathivanan; Ramachandran, B.; Balasubramanian, S.; Raghuram, K.

2013-01-01

315

High-Voltage Power Supply System for Laser Isotope Separation  

SciTech Connect

This report presents several concepts for Laser High-Voltage Power Supply (HVPS) Systems for a Laser Isotope Separation facility. Selection of equipments and their arrangement into operational systems is based on proven designs and on application concepts now being developed. This report has identified a number of alternative system arrangements and has provided preliminary cost estimates for each. The report includes a recommendation for follow-on studies that will further define the optimum Laser HVPS Systems. Brief descriptions are given of Modulator/Regulator circuit trade-offs, system control interfaces, and their impact on costs.

Ketaily, E.C.; Buckner, R.P.; Uhrik, R.L.

1979-06-26

316

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices  

DOEpatents

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

Chassin, David P. (Pasco, WA); Donnelly, Matthew K. (Kennewick, WA); Dagle, Jeffery E. (Richland, WA)

2006-12-12

317

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices  

DOEpatents

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

Chassin, David P. (Pasco, WA); Donnelly, Matthew K. (Kennewick, WA); Dagle, Jeffery E. (Richland, WA)

2011-12-06

318

Cyber security of the electric power grid  

Microsoft Academic Search

Economic security and quality of life in modern society depend on the reliable supply and delivery of electric power. New cyber security vulnerabilities are emerging that introduce new risks to the Nation's electric power grid. This presentation will describe issues, trends, and research opportunities for enhancing the cyber security of control systems associated with electric power system operations.

J. E. Dagle

2009-01-01

319

Reactive power control of wind farms for voltage control applications  

Microsoft Academic Search

In the last few years, there is a strong trend towards decentralised production and supply, leading to a situation where a growing number of small and medium size producers will be connected to energy networks. But at the same time, the power quality of the generation must be ensured and this means that the electrical parameters of the distribution network

A. Tapia; G. Tapia; J. X. Ostolaza

2004-01-01

320

Voltage limitation by autonomous reactive power control of grid connected photovoltaic inverters  

Microsoft Academic Search

The increasing decentralized power generation in the public low voltage grid may lead to a reversed load flow. The common assumption that the highest voltage in a low voltage grid is on the transformer busbar is then no longer appropriate. Therefore the risk of overvoltages rises significantly. A highly effective way to keep the voltage within the allowed bandwidth is

G. Kerber; R. Witzmann; H. Sappl

2009-01-01

321

Repetitive control for a dynamic voltage restorer for power-quality improvement  

Microsoft Academic Search

This paper presents a control system based on a repetitive controller to compensate key power-quality disturbances, namely voltage sags, harmonic voltages and voltage imbalances, using a dynamic voltage restorer (DVR). The control scheme deals with all three disturbances simultaneously within a specified bandwidth. The control structure contains a feed-forward term to improve the transient response and a feedback term to

Pedro Roncero-Sanchez; Enrique Acha; Jose Enrique Ortega-Calderon; Vicente Feliu Batlle; A. Garcia-Cerrada

2009-01-01

322

A Versatile Control Scheme for a Dynamic Voltage Restorer for Power-Quality Improvement  

Microsoft Academic Search

This paper presents a control system based on a repetitive controller to compensate for key power-quality disturbances, namely voltage sags, harmonic voltages, and voltage imbalances, using a dynamic voltage restorer (DVR). The control scheme deals with all three disturbances simultaneously within a bandwidth. The control structure is quite simple and yet very robust; it contains a feedforward term to improve

Pedro Roncero-Sanchez; Enrique Acha; Jose Enrique Ortega-Calderon; Vicente Feliu; Aurelio Garcia-Cerrada

2009-01-01

323

Reactive Power Management of a DFIG Wind System in Microgrids Based on Voltage Sensitivity Analysis  

Microsoft Academic Search

This paper addresses the problem of voltage regu- lation in microgrids that include doubly fed induction generator (DFIG)-based wind generation. Due to significant line resistances in microgrids, active power variations produced by wind turbines can lead to significant fluctuations in voltage magnitudes. This paper proposes a voltage sensitivity analysis-based scheme to achieve voltage regulation at a target bus in such

Rasool Aghatehrani; Rajesh Kavasseri

2011-01-01

324

Low power voltage limiter design for a full passive UHF RFID sensor  

Microsoft Academic Search

This paper presents a low power voltage limiter design that avoids possible damages in the circuits of the analog front-end of the RFID sensor due to voltage surges whenever reader and tag are very close. The proposed voltage limiter design takes advantage of the implemented bandgap reference and voltage regulator in order to provide low temperature and process deviation of

E. Fernandez; A. Beriain; H. Solar; A. Garcia-Alonso; R. Berenguer; J. Sosa; J. M. Monzon; S. Garcia-Alonso; J. A. Montiel-Nelson

2011-01-01

325

Power Control of New Wind Power Generation System with Induction Generator Excited by Voltage Source Converter  

NASA Astrophysics Data System (ADS)

This paper investigates advantages of new combination of the induction generator for wind power and the power electronic equipment. Induction generator is popularly used for the wind power generation. The disadvantage of it is impossible to generate power at the lower rotor speed than the synchronous speed. To compensate this disadvantage, expensive synchronous generator with the permanent magnets is sometimes used. In proposed scheme, the diode rectifier is used to convert the real power from the induction generator to the intermediate dc voltage, while only the reactive power necessary to excite the induction generator is supplied from the voltage source converter (VSC). This means that the rating of the expensive VSC is minimized and total cost of the wind power generation system is decreased compared to the system with synchronous generator. Simulation study to investigate the control strategy of proposed system is performed. The results show the reduction of the VSC rating is prospective.

Morizane, Toshimitsu; Kimura, Noriyuki; Taniguchi, Katsunori

326

DC/DC Power Converter for Super-Capacitor Supplied by Electric Power Splitter  

NASA Astrophysics Data System (ADS)

The aim of the article is design of DC/DC converter and discussing of problematic supply using electric power splitter. The electric power splitter with AC/DC converter is source for the DC/DC converter, which is dedicated for charging and discharging of hybrid car drive super-capacitor energy storage. The electric power splitter is synchronous machine with two rotating parts. First rotor contains permanent magnet and the second rotor contains three-phase windings. The amplitude of output voltage depends on difference between first and second rotor speed. The main role of the DC/DC converter is to optimize energy content in super-capacitor storage used to acceleration and deceleration driving period of the passenger car with hybrid electric vehicle (HEV) drive system using electric power splitter.

Haubert, T.; Mindl, P.

327

Impacts of Large Scale and High Voltage Level Photovoltaic Penetration on the Security and Stability of Power System  

Microsoft Academic Search

Grid-connected photovoltaic (PV) systems are developing increasingly in recent years due to many associated economic and environmental factors and provoking control and operation problems to utilities. Most of all, it also touches the essence of management mechanism of power systems. Concerning with voltage and frequency stability, electricity quality and short-term load forecasting, the possible influences on the secure and stable

Yang Weidong; Zhou Xia; Xue Feng

2010-01-01

328

Limiting electric fields of HVDC overhead power lines.  

PubMed

As a consequence of the increased use of renewable energy and the now long distances between energy generation and consumption, in Europe, electric power transfer by high-voltage (HV) direct current (DC) overhead power lines gains increasing importance. Thousands of kilometers of them are going to be built within the next years. However, existing guidelines and regulations do not yet contain recommendations to limit static electric fields, which are one of the most important criteria for HVDC overhead power lines in terms of tower design, span width and ground clearance. Based on theoretical and experimental data, in this article, static electric fields associated with adverse health effects are analysed and various criteria are derived for limiting static electric field strengths. PMID:24573710

Leitgeb, N

2014-05-01

329

Wind Power Forecasting and Electricity Market Operations  

Microsoft Academic Search

In this paper we give a brief overview of wind power forecasting models and how they are used in power system and electricity market operations. We focus on the organized electricity markets in the United States, where several independent system operators (ISOs\\/RTOs) have recently introduced wind power forecasting systems as part of their operations. We find that wind power forecasting

Audun Botterud; Jianhui Wang; Cláudio Monteiro; Vladimiro Miranda

330

Architecture for a High-to-Medium-Voltage Power Converter  

NASA Technical Reports Server (NTRS)

A power converter now undergoing development is required to operate at a DC input potential ranging between 5.5 and 10 kV and a DC output potential of 400 V at a current up to 25 A. This power converter is also required to be sufficiently compact and reliable to fit and operate within the confines of a high-pressure case to be lowered to several miles (approx.5 km) below the surface of the ocean. The architecture chosen to satisfy these requirements calls for a series/ parallel arrangement of 48 high-frequency, pulse-width-modulation (PWM), transformer-isolation DC-to-DC power converter blocks. The input sides of the converter blocks would be connected in series so that the input potential would be divided among them, each of them being exposed to an input potential of no more than 10 kV/48 . 210 V. The series connection of inputs would also enforce a requirement that all the converter blocks operate at the same input current. The outputs of the converter blocks would be connected in a matrix comprising 6 parallel legs, each leg being a cascade of eight outputs wired in series (see figure). All the converter blocks would be identical within the tolerances of the values of their components. A single voltage feedback loop would regulate the output potential. All the converter blocks would be driven by the same PWM waveform generated by this feedback loop. The power transformer of each converter block would have a unity turns ratio and would be capable of withstanding as much as 10 kVDC between its primary and secondary windings. (Although, in general, the turns ratio could be different from unity, the simplest construction for minimizing leakage and maximizing breakdown voltage is attained at a turns ratio of unity.)

Vorpenian, Vatche

2008-01-01

331

Electrical characterization of Al\\/MEH-PPV\\/pSi Schottky diode by current–voltage and capacitance–voltage methods  

Microsoft Academic Search

The electrical characterization of the Al\\/poly[2-methoxy-5-(2?-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV)\\/p-Si structure has been investigated by current–voltage and capacitance–voltage methods. The Al\\/MEH-PPV\\/p-Si Schottky diode with the ideality factor value of 1.88 obeys a metal–interfacial layer–semiconductor (MIS) configuration rather than an ideal Schottky diode due to the existence of an insulating layer on the organic semiconductor. The barrier height (?b,o=0.80eV) obtained from the I–V characteristic

Mehmet Enver Aydin; Fahrettin Yakuphanoglu; Jae-Hoon Eom; Do-Hoon Hwang

2007-01-01

332

75 FR 23823 - Sixth Northwest Electric Power and Conservation Plan  

Federal Register 2010, 2011, 2012, 2013

...PACIFIC NORTHWEST ELECTRIC POWER AND CONSERVATION PLANNING COUNCIL Sixth Northwest Electric Power and Conservation Plan AGENCY: Pacific Northwest Electric Power and Conservation Planning Council...

2010-05-04

333

Design of new diesel-electric power supply unit for military vehicles  

Microsoft Academic Search

This paper introduces a new designed diesel-electric power-supply unit developed for military purposes. The power-supply unit is divided to two main electric parts, (i) input part which is composed of a sensorless controlled active voltage source rectifier supplied by a permanent magnet synchronous generator, and (ii) output part which is composed of a four-leg three-phase voltage source inverter with a

Z. Peroutka; T. Glasberger; J. Molna?r

2010-01-01

334

More-electric aircraft electrical power system accelerated functional modeling  

Microsoft Academic Search

The development of future more-electric aircraft (MEA) is a major trend in modern aircraft electric power system (EPS) engineering that results in a significantly increased number of onboard loads driven by power-electronics. Development of appropriate EPS architectures, ensuring the power system integrity, stability and assessment of overall system quality and performance under possible normal and abnormal scenarios requires extensive simulation

S. V. Bozhko; T. Wu; Y. Tao; G. M. Asher

2010-01-01

335

Electric power annual 1997. Volume 1  

SciTech Connect

The Electric Power Annual presents a summary of electric power industry statistics at national, regional, and State levels. The objective of the publication is to provide industry decisionmakers, government policy-makers, analysts, and the general public with data that may be used in understanding US electricity markets. The Electric Power Annual is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy. Volume 1 -- with a focus on US electric utilities -- contains final 1997 data on net generation and fossil fuel consumption, stocks, receipts, and cost; preliminary 1997 data on generating unit capability, and retail sales of electricity, associated revenue, and the average revenue per kilowatthour of electricity sold (based on a monthly sample: Form EIA-826, ``Monthly Electric Utility Sales and Revenue Report with State Distributions``). Additionally, information on net generation from renewable energy sources and on the associated generating capability is included in Volume 1 of the EPA.

NONE

1998-07-01

336

Optimal control of static VAr compensators in power supply systems with electrical arc furnaces  

Microsoft Academic Search

Electrical arc furnaces (EAF) with power ratings of, in-part, far more than 100 MVA, cause voltage fluctuations and flicker in the supplying power system. Static VAr Compensators (SVC) are typically used for reactive power compensation. This paper presents a solution for how to obtain an optimum flicker reduction at a comparatively low compensator power rating by an anti-windup extension of

Steffen Prinz; H. Pietzsch; Dietrich Stade

2005-01-01

337

Electric Power System Analysis and Design of an Expanding Steel Cogeneration Plant  

Microsoft Academic Search

This paper presents the electric power system analysis and design of an expanding steel cogeneration plant. The power system configuration and the equipment parameters of the cogeneration plant are well designed according to the power flow, short circuit, voltage fluctuation, harmonic flow and transient stability analyses. According to the power flow analysis, the site and capacity of shunt capacitor banks

Cheng-Ting Hsu; Chao-Shun Chen; Chia-Hung Lin

2010-01-01

338

An assessment of reactive power\\/voltage control devices in distribution networks  

Microsoft Academic Search

This paper provides an assessment of candidate voltage\\/reactive power control devices for distribution systems. The recent trend toward distributed energy resources (DERs), and distributed generation (DG), in particular, is often based on the rationale to support voltage and compensate for reactive power closer to the end users. This situation calls for a systematic approach to assessing alternatives for voltage control,

Anupam A. Thatte; Marija D. Ilic

2006-01-01

339

Automated low-power technique exploiting multiple supply voltages applied to a media processor  

Microsoft Academic Search

This paper describes an automated design technique to reduce power by making use of two supply voltages. The technique consists of structure synthesis, placement, and routing. The structure synthesizer clusters the gates off the critical paths so as to supply the reduced voltage to save power. The placement and routing tool assigns either the reduced voltage or the unreduced one

Kimiyoshi Usami; Mutsunori Igarashi; Fumihiro Minami; Takashi Ishikawa; M. Kanzawa; Makoto Ichida; Kazutaka Nogami

1998-01-01

340

DEVELOPMENT OF THE KLYSTRON MODULATOR USING A HIGH VOLTAGE INVERTER POWER SUPPLY  

Microsoft Academic Search

The existing klystron modulator in the Linac use a 60 Hz high voltage power supply and adopt traditional L-C resonant charging scheme with De-Qing circuit. The stability of the output high voltage is not satisfactory especially when the AC line voltage fluctuations. If an inverter power supply is used as a HV generator, it will just meet the demands A

Y. G. Son; S. J. Kwon; D. E. Kim; C. W. Chung

2007-01-01

341

Wildlife and electric power transmission  

USGS Publications Warehouse

Hundreds of thousands of miles of transmission lines have been introduced into our natural environment. These lines and their corridors can be damaging or beneficial to wildlife communities depending on how they are designed, where they are placed, and when they are constructed and maintained. With the current trend toward UHV systems, new problems (associated with additional increments in audible noise, electric and magnetic force fields, etc.) must be addressed. We recommend the following areas for careful study: (1) the response of wilderness species to transmission lines and line construction and maintenance activities (2) the magnitude of bird collision and electrocution mortality, (3) the response of power corridor and power tower in habiting wildlife to laboratory and field doses of electro-chemical oxidants, corona noise, electric and magnetic fields, etc., (4) the productivity of tower inhabiting birds compared with nearby non-tower nesters, and (5) the influence of powerline corridors on mammalian and avian migration patterns. It is our hope that the questions identified in this study will help stimulate further research so that we can maximize wildlife benefits and minimize wildlife detriments.

Ellis, D.H.; Goodwin, J.G., Jr.; Hunt, J.R.

1978-01-01

342

Advanced Electric Distribution, Switching, and Conversion Technology for Power Control  

NASA Technical Reports Server (NTRS)

The Electrical Power Control Unit currently under development by Sundstrand Aerospace for use on the Fluids Combustion Facility of the International Space Station is the precursor of modular power distribution and conversion concepts for future spacecraft and aircraft applications. This unit combines modular current-limiting flexible remote power controllers and paralleled power converters into one package. Each unit includes three 1-kW, current-limiting power converter modules designed for a variable-ratio load sharing capability. The flexible remote power controllers can be used in parallel to match load requirements and can be programmed for an initial ON or OFF state on powerup. The unit contains an integral cold plate. The modularity and hybridization of the Electrical Power Control Unit sets the course for future spacecraft electrical power systems, both large and small. In such systems, the basic hybridized converter and flexible remote power controller building blocks could be configured to match power distribution and conversion capabilities to load requirements. In addition, the flexible remote power controllers could be configured in assemblies to feed multiple individual loads and could be used in parallel to meet the specific current requirements of each of those loads. Ultimately, the Electrical Power Control Unit design concept could evolve to a common switch module hybrid, or family of hybrids, for both converter and switchgear applications. By assembling hybrids of a common current rating and voltage class in parallel, researchers could readily adapt these units for multiple applications. The Electrical Power Control Unit concept has the potential to be scaled to larger and smaller ratings for both small and large spacecraft and for aircraft where high-power density, remote power controllers or power converters are required and a common replacement part is desired for multiples of a base current rating.

Soltis, James V.

1998-01-01

343

Anomalous failure in low-voltage p-chanel power MOSFETs during the intrinsic diode recovery time  

Microsoft Academic Search

This paper studies and analyzes the root causes of anomalous failures of low-voltage p-channel power MOSFETs during the intrinsic diode recovery time in dV\\/dt test. In particular, the dV\\/dt characterization test is described and, afterwards, specific electrical tests are provided to explain the root causes. From the electrical results point of view, the dV\\/dt slew rate does not involve an

G. Consentino; G. Ardita

2008-01-01

344

Power system voltage contingency assessment by adjoint network  

Microsoft Academic Search

The adjoint network method used for the security analyses encounters difficulties in calculating postcontingency voltage due to linear approximation of the voltage and current changes. It is proposed that bus voltage changes be compensated. An improved scheme is suggested for the bus voltage correction and efficiency. The proposed scheme is analyzed for an example involving the 39-bus New England test

F. Gubina; R. Golob

1991-01-01

345

Electrical biasing and voltage contrast imaging in a focused ion beam system  

SciTech Connect

We present two new techniques that enhance conventional focused ion beam (FIB) system capabilities for integrated circuit (IC) analysis: in situ electrical biasing and voltage contrast imaging. We have used in situ electrical biasing to enable a number of advanced failure analysis applications including (1) real time evaluation of device electrical behavior during milling and deposition, (2) verification of IC functional modifications without removal from the FIB system, and (3) ultraprecision control for cross sectioning of deep submicron structures, such as programmed amorphous silicon antifuses. We have also developed FIB system voltage contrast imaging that can be used for a variety of failure analysis applications. The use of passive voltage contrast imaging for defect localization and for navigation on planarized devices will be illustrated. In addition, we describe new, biased voltage contrast imaging techniques and provide examples of their application to the failure analysis of complex ICs. We discuss the necessary changes in system operating parameters to perform biased voltage contrast imaging.

Campbell, A.N.; Soden, J.M.; Rife, J.L. [Sandia National Labs., Albuquerque, NM (United States); Lee, R.G. [Micrion Corp., Peabody, MA (United States)

1995-09-01

346

Precise time and time interval applications to electric power systems  

NASA Technical Reports Server (NTRS)

There are many applications of precise time and time interval (frequency) in operating modern electric power systems. Many generators and customer loads are operated in parallel. The reliable transfer of electrical power to the consumer partly depends on measuring power system frequency consistently in many locations. The internal oscillators in the widely dispersed frequency measuring units must be syntonized. Elaborate protection and control systems guard the high voltage equipment from short and open circuits. For the highest reliability of electric service, engineers need to study all control system operations. Precise timekeeping networks aid in the analysis of power system operations by synchronizing the clocks on recording instruments. Utility engineers want to reproduce events that caused loss of service to customers. Precise timekeeping networks can synchronize protective relay test-sets. For dependable electrical service, all generators and large motors must remain close to speed synchronism. The stable response of a power system to perturbations is critical to continuity of electrical service. Research shows that measurement of the power system state vector can aid in the monitoring and control of system stability. If power system operators know that a lightning storm is approaching a critical transmission line or transformer, they can modify operating strategies. Knowledge of the location of a short circuit fault can speed the re-energizing of a transmission line. One fault location technique requires clocks synchronized to one microsecond. Current research seeks to find out if one microsecond timekeeping can aid and improve power system control and operation.

Wilson, Robert E.

1992-01-01

347

Precise time and time interval applications to electric power systems  

NASA Astrophysics Data System (ADS)

There are many applications of precise time and time interval (frequency) in operating modern electric power systems. Many generators and customer loads are operated in parallel. The reliable transfer of electrical power to the consumer partly depends on measuring power system frequency consistently in many locations. The internal oscillators in the widely dispersed frequency measuring units must be syntonized. Elaborate protection and control systems guard the high voltage equipment from short and open circuits. For the highest reliability of electric service, engineers need to study all control system operations. Precise timekeeping networks aid in the analysis of power system operations by synchronizing the clocks on recording instruments. Utility engineers want to reproduce events that caused loss of service to customers. Precise timekeeping networks can synchronize protective relay test-sets. For dependable electrical service, all generators and large motors must remain close to speed synchronism. The stable response of a power system to perturbations is critical to continuity of electrical service. Research shows that measurement of the power system state vector can aid in the monitoring and control of system stability. If power system operators know that a lightning storm is approaching a critical transmission line or transformer, they can modify operating strategies. Knowledge of the location of a short circuit fault can speed the re-energizing of a transmission line. One fault location technique requires clocks synchronized to one microsecond. Current research seeks to find out if one microsecond timekeeping can aid and improve power system control and operation.

Wilson, Robert E.

1992-07-01

348

Transformerless Hybrid Topology for Medium-Voltage Reactive-Power Compensation  

Microsoft Academic Search

In this paper, natural sinusoidal hybrid converter is presented for medium-voltage reactive-power control applications. Main high-voltage inverter that produces fundamental reactive current is a square-wave inverter. Several single-phase full-bridge converters are connected in series with this square inverter to elim- inate harmonic voltages from the net output voltage of this hybrid converter. DC bus voltages of these cells are naturally

Malaya Kumar Sahu; Gautam Poddar

2011-01-01

349

Measurements of corona ion induced atmospheric electricity modification near to HV power lines  

Microsoft Academic Search

Corona ions emitted from high voltage power lines and propagated by the wind can attach at a given rate to atmospheric aerosols and will create disturbances in the Earth's DC electric field. Local electric field variations have been measured using field meters upwind and downwind of power lines and a fixed site monitoring station has been built to enable space

J. C. Matthews; A. J. Buckley; P. A. Keitch; M. D. Wright; D. L. Henshaw

2008-01-01

350

Nonlinear behavior of electric power transmission through an elastic wall by acoustic waves and piezoelectric transducers  

Microsoft Academic Search

Weakly nonlinear behavior of electric power transmission through an elastic wall by piezoelectric transducers and acoustic waves near resonance is studied based on the cubic theory of nonlinear electroelasticity. An approximate analytical solution is obtained. Output voltage is calculated and plotted. Basic nonlinear behaviors of the power transmission structure are examined. It is found that near nonlinear resonance the electrical

Zengtao Yang; Jiashi Yang; Yuantai Hu

2008-01-01

351

Evolutionary approach to optimisation of the operation of electric power distribution networks  

Microsoft Academic Search

An idea of using a classifying system and co-evolutionary algorithm for operation support of electric power distribution systems operators has been presented in the paper. The method proposed by the author of the work is typified by the short time of designating the most rational post breakdown configurations in complex electric power Medium Voltage distribution network structures. It is the

Sylwester Filipiak

2013-01-01

352

PMUs optimized allocation using a tabu search algorithm for fault location in electric power distribution system  

Microsoft Academic Search

Phasor measurement units (PMUs) optimized allocation allows control, monitoring and accurate operation of electric power distribution systems, improving reliability and service quality. Good quality and considerable results are obtained for transmission systems using fault location techniques based on voltage measurements. Based on these techniques and performing PMUs optimized allocation it is possible to develop an electric power distribution system fault

R. A. F. Pereira; L. G. W. da Silva; J. R. S. Mantovani

2004-01-01

353

A SIMULINK study of electric arc furnace power quality improvement by using STATCOM  

Microsoft Academic Search

The nonlinear and time varying nature of electric arc furnaces (EAFs) create flicker, harmonics, and voltage\\/current unbalances. Nowadays to improve the performance of EAFs and the power quality problems of electrical systems around them high speed compensators like STATCOM are needed. This paper uses a time domain model for electric arc furnaces and a new model of STATCOM respectively for

A. Tavakkoli; M. Ehsan; S. Batahiee; M. Marzband

2008-01-01

354

Oce Nemp Program. Development of Criteria for Protection of Nike-X Power Plant and Facilities Electrical Systems Against Nuclear Electromagnetic Pulse Effects. Magnetically Induced Voltages on Conductors within Conduits and Cables.  

National Technical Information Service (NTIS)

This document describes a series of tests to determine the magnetically induced voltages on conductors within conduit as influenced by such parameters as conductor position, conduit joints, bends, diameter, wall thickness, length, material, etc. Other rac...

H. H. Brustle L. C. Walko

1967-01-01

355

Reliability models for electric power production costing  

Microsoft Academic Search

The paper describes the use of reliability models for estimating the cost of producing electric power. One of the features of electricity production is that it cannot be conveniently stored, and therefore at every instant of time there should be sufficient production to meet the demand. Thus the availability of the generating units plays a key role in electric power

M. Mazumdar; A. Kapoor

1998-01-01

356

A market mechanism for electric power transmission  

Microsoft Academic Search

As competition is introduced into the electric power industry, access and pricing policy for transmission will play a pivotal role in shaping future market structure and performance. The externalities associated with the loop flow phenomenon in an electric power network constitute a significant barrier to the formation of efficient markets for electricity and transmission services. In this paper, we present

Hung-Po Chao; Stephen Peck

1996-01-01

357

Hybrid fiber optic voltage sensor for remote monitoring of electrical submersible pump motors  

Microsoft Academic Search

We report on the design and experimental evaluation of the hybrid fiber Bragg grating (FBG) piezoelectric voltage sensor developed specifically for remote monitoring of electrical submersible pump (ESP) motors. Unlike a previously reported transducer based on a single piezoelectric element, the voltage rating of the presented device could be as low as 500 V due to the use of a

Lukasz Dziuda; Pawel Niewczas; Grzegorz Fusiek; James R. McDonald

2005-01-01

358

Apparatus and Method for Calibrating Voltage Spike Waveforms for Three- Phase Electrical Devices and Systems.  

National Technical Information Service (NTIS)

This patent application discloses an apparatus and method for calibrating three-phase voltage spike waveforms used in testing three-phase electrical devices. The apparatus includes a circuit having a plurality of phase voltage lines and a ground line. Pha...

J. M. Muhitch

2003-01-01

359

Influence of RMS variation measurement protocols on electrical system performance indices for voltage sags and swells  

Microsoft Academic Search

This paper presents an evaluation study for measurement protocols of characteristic parameters related to short duration voltage variations (SDVs). The evaluation of possible differences in the magnitude and the duration of SDVs produced by different protocols is of great importance, for the electrical system performance indices related to voltage sags and swells are in practice obtained by measuring instruments. The

N. Kagan; E. L. Ferrari; N. M. Matsuo; S. X. Duarte; A. Sanommiya; J. L. Cavaretti; U. F. Castellano; A. Tenorio

2000-01-01

360

Ultra Low-Voltage\\/Low-Power Digital Floating-Gate Circuits  

Microsoft Academic Search

This paper describes a novel technique for implementing ultra low-voltage\\/low-power digital circuits. The effective threshold voltage seen from a control gate is adjusted during a UV-light activated tuning procedure. The optimal effective threshold voltage matching the supply voltage and speed may be programmed by UV-light through an activated conductance between the power-rails and the floating gates. Measured results are provided

Y. Berg; D. t. Wisland; T. s. Lande

1999-01-01

361

Test results of a resistive SC-power switch of 40 MW switching power at a voltage of 47 kV  

Microsoft Academic Search

After a brief description of the function of an sc. resistive switch in an electrical network and of the basic design formula, results are presented of the switch test. Special developments are described which are necessary for successful switch operation. They include the control of the high power density in the switch conductor, the application of high voltage technique to

A. Ulbricht

1979-01-01

362

Urban exposure to ELF magnetic field due to high-, medium- and low-voltage electricity supply networks.  

PubMed

The regional environment protection agency (ARPA) of the Aosta Valley region in north Italy performed a survey of magnetic field triggered by the power supply network in high, medium and low voltages on the entire area of Aosta town. The electrical distribution system for houses was not however taken into account. The aim of the survey was to evaluate the global population exposure and not simply the assessment of the legal exposure limit compliance. PMID:19843546

Bottura, V; Cappio Borlino, M; Carta, N; Cerise, L; Imperial, E

2009-12-01

363

Mine electrical power systems. Transients protection, reliability investigation, and safety testing of mine electrical power systems. Volume V--periodic inspection of mine electrical power systems. Open file report (final) 24 Jun 74-15 aug 78  

Microsoft Academic Search

This report presents the results of an investigation into the feasibility of periodically measuring parameters of the insulation for a mine electrical power system to detect incipient faults. The variety of insulation parameters evaluated included insulation resistance, dissipation factor, power factor (versus applied voltage), current harmonics, leakage current, infrared radiation, as well as certain circuit breaker parameters and tests. To

E. K. Stanek; M. M. Hassan; Y. C. Chou; H. Shamash

1979-01-01

364

Reducing the Vulnerability of Electric Power Grids to Terrorist Attacks  

Microsoft Academic Search

This report describes the development of a cascading outage analyzer that, given an initial disturbance on an electric power system, checks for thermal overloads, under-frequency and over-frequency conditions, and under-voltage conditions that would result in removal of elements from the system. The analyzer simulates the successive tripping of elements due to protective actions until a post-event steady state or a

Ross Baldick; Thekla Boutsika; Jin Hur; Manho Joung; Yin Wu; Minqi Zhong

2009-01-01

365

Reducing the Vulnerability of Electric Power Grids to Terrorist Attacks  

SciTech Connect

This report describes the development of a cascading outage analyzer that, given an initial disturbance on an electric power system, checks for thermal overloads, under-frequency and over-frequency conditions, and under-voltage conditions that would result in removal of elements from the system. The analyzer simulates the successive tripping of elements due to protective actions until a post-event steady state or a system blackout is reached.

Ross Baldick; Thekla Boutsika; Jin Hur; Manho Joung; Yin Wu; Minqi Zhong

2009-01-31

366

Battery model for electrical power system energy balance  

NASA Technical Reports Server (NTRS)

A model to simulate nickel-cadmium battery performance and response in a spacecraft electrical power system energy balance calculation was developed. The voltage of the battery is given as a function of temperature, operating depth-of-charge (DOD), and battery state-of-charge. Also accounted for is charge inefficiency. A battery is modeled by analysis of the results of a multiparameter battery cycling test at various temperatures and DOD's.

Hafen, D. P.

1983-01-01

367

A new hybrid series active filter configuration to compensate voltage sag, swell, voltage and current harmonics and reactive power  

Microsoft Academic Search

This paper proposes a new system configuration for a series hybrid power filter (SHPF) realized for all harmonic types of loads. The series hybrid filter consists of a small rated series active power filter (SAPF) and a shunt passive filter with variable inductance using a thyristor control reactor (TCR). The DC voltage available at the load side of a typical

A. Hamadi; S. Rahmani; K. Al-Haddad

2009-01-01

368

Pattern recognition for electric power system protection  

NASA Astrophysics Data System (ADS)

The objective of this research is to demonstrate pattern recognition tools such as decision trees (DTs) and neural networks that will improve and automate the design of relay protection functions in electric power systems. Protection functions that will benefit from the research include relay algorithms for high voltage transformer protection (TP) and for high impedance fault (HIF) detection. A methodology, which uses DTs and wavelet analysis to distinguish transformer internal faults from other conditions that are easily mistaken for internal faults, has been developed. Also, a DT based solution is proposed to discriminate HIFs from normal operations that may confuse relays. Both methods have been verified with simulation data generated by the Electromagnetic Transients Program. Compared with traditional methods, both show better performance. After being trained with a large number of carefully selected features, the desired DTs can obtain an accuracy of greater than 95%. Further, no special equipment is necessary; the DT-based controller only needs the standard relay input signals sampled at 1920 Hz. So far, no one has applied the same methodologies to solve these problems. Even though some future work with experimental data is needed to make the methods more convincing for utilities, the research has already shown that pattern recognition is a promising direction in developing power system protection algorithms.

Sheng, Yong

2002-11-01

369

Wind wheel electric power generator  

NASA Technical Reports Server (NTRS)

Wind wheel electric power generator apparatus includes a housing rotatably mounted upon a vertical support column. Primary and auxiliary funnel-type, venturi ducts are fixed onto the housing for capturing wind currents and conducting to a bladed wheel adapted to be operatively connected with the generator apparatus. Additional air flows are also conducted onto the bladed wheel; all of the air flows positively effecting rotation of the wheel in a cumulative manner. The auxiliary ducts are disposed at an acute angle with respect to the longitudinal axis of the housing, and this feature, together with the rotatability of the housing and the ducts, permits capture of wind currents within a variable directional range.

Kaufman, J. W. (inventor)

1980-01-01

370

Modification of atmospheric DC fields by space charge from high-voltage power lines  

NASA Astrophysics Data System (ADS)

Corona ion discharge is responsible for a flux of small ions emanating from an overhead power line capable of modifying the ambient electrical environment. The ensuing space charge can be detected as a change in magnitude of the earth's natural DC electric field at ground level. DC field mill meters were used to measure the vertical component of electric fields upwind and downwind of 132 and 400 kV power lines. Evidence of space charge blowing downwind of power lines was observed in 21 out of 22 cases. Time series measurements recorded in the downwind direction were highly variable with fields of higher magnitude compared to those recorded upwind. Model DC field profiles were used to estimate a lower limit to the space charge density at body height arising from power lines. The average lower limit was ˜3000 cm -3 excess unipolar charges. The result suggests that between 10% and 60% of outdoor aerosols gain excess charge by the attachment of corona ions. Downwind of a 400 kV line in Somerset that was prone to excessive corona discharge, the estimated mean lower limit excess unipolar space charge density was ˜6000 cm -3, suggesting that up to 100% of aerosols gain excess charge by the attachment of corona ions. Investigations into the time variation of DC electric fields around motorways and the natural diurnal variation of the earth's DC field were also undertaken and compared to the power line data. The results show that the power line time series are clearly distinguishable from typical examples of both types of field variation, demonstrating the relatively highly charged atmospheres that generally exist around high-voltage power lines. The results are of potential public health concern, because they suggest a degree of aerosol charging that may result in a non-trivial increase in lung deposition of inhaled pollutant aerosols.

Fews, A. P.; Wilding, R. J.; Keitch, P. A.; Holden, N. K.; Henshaw, D. L.

371

Electric power substation capital costs  

SciTech Connect

The displacement or deferral of substation equipment is a key benefit associated with several technologies that are being developed with the support of the US Department of Energy`s Office of Utility Technologies. This could occur, for example, as a result of installing a distributed generating resource within an electricity distribution system. The objective of this study was to develop a model for preparing preliminary estimates of substation capital costs based on rudimentary conceptual design information. The model is intended to be used by energy systems analysts who need ``ballpark`` substation cost estimates to help establish the value of advanced utility technologies that result in the deferral or displacement of substation equipment. This cost-estimating model requires only minimal inputs. More detailed cost-estimating approaches are recommended when more detailed design information is available. The model was developed by collecting and evaluating approximately 20 sets of substation design and cost data from about 10 US sources, including federal power marketing agencies and private and public electric utilities. The model is principally based on data provided by one of these sources. Estimates prepared with the model were compared with estimated and actual costs for the data sets received from the other utilities. In general, good agreement (for conceptual level estimating) was found between estimates prepared with the cost-estimating model and those prepared by the individual utilities. Thus, the model was judged to be adequate for making preliminary estimates of typical substation costs for US utilities.

Dagle, J.E.; Brown, D.R.

1997-12-01

372

Hybrid Method to Assess Sensitive Process Interruption Costs Due to Faults in Electric Power Distribution Networks  

Microsoft Academic Search

This paper shows a new hybrid method for risk assessment regarding interruptions in sensitive processes due to faults in electric power distribution systems. This method determines indices related to long duration interruptions and short duration voltage variations (SDVV), such as voltage sags and swells in each customer supplied by the distribution network. Frequency of such occurrences and their impact on

Juan C. Cebrian; Nelson Kagan

2010-01-01

373

Electric power annual 1997. Volume 2  

SciTech Connect

The Electric Power Annual 1997, Volume 2 contains annual summary statistics at national, regional, and state levels for the electric power industry, including information on both electric utilities and nonutility power producers. Included are data for electric utility retail sales of electricity, associated revenue, and average revenue per kilowatthour of electricity sold; financial statistics; environmental statistics; power transactions; and demand-side management. Also included are data for US nonutility power producers on installed capacity; gross generation; emissions; and supply and disposition of energy. The objective of the publication is to provide industry decisionmakers, government policymakers, analysts, and the general public with historical data that may be used in understanding US electricity markets. 15 figs., 62 tabs.

NONE

1998-10-01

374

High-voltage, high-power, solid-state remote power controllers for aerospace applications  

NASA Technical Reports Server (NTRS)

Two general types of remote power controller (RPC) that combine the functions of a circuit breaker and a switch were developed for use in direct-current (dc) aerospace systems. Power-switching devices used in these designs are the relatively new gate-turnoff thyristor (GTO) and poweer metal-oxide-semiconductor field-effect transistors (MOSFET). The various RPC's can switch dc voltages to 1200 V and currents to 100 A. Seven different units were constructed and subjected to comprehensive laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times to limit voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout and microsecond tripout for large overloads. The basic circuits developed can be used to build switchgear limited only by the ratings of the switching device used.

Sturman, J. C.

1985-01-01

375

Design of high-voltage, high-power, solid state remote power controllers for aerospace applications  

NASA Technical Reports Server (NTRS)

Two general types of remote power controllers (RPC's), which combine the functions of a circuit breaker and a switch, were developed for use in dc aerospace systems. Power-switching devices used in the designs are the gate-turnoff thyristor (GTO) and MOSFET. The RPC's can switch dc voltages to 1200 V and currents to 1000 A. Seven different units were constructed and subjected to laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times which limit surge currents and voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout proportional to I sq T and microsecond tripout for large overloads.

Sturman, J. C.

1985-01-01

376

Design considerations for high-voltage high-power full-bridge zero-voltage-switched PWM converter  

Microsoft Academic Search

A steady-state analysis is presented with complete characterization of the converter operation. A small-signal model of the converter is established. The design procedures based on the analysis are presented and the various losses in the circuit assessed. Critical design considerations for a high-power, high-voltage application are analyzed. The results of the analysis are verified using a high-voltage. 2 kW prototype

J. A. Sabate; V. Vlatkovic; R. B. Ridley; F. C. Lee; B. H. Cho

1990-01-01

377

Solar energy thermally powered electrical generating system  

NASA Technical Reports Server (NTRS)

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

Owens, William R. (Inventor)

1989-01-01

378

Electric Power: Decisions for the Future.  

ERIC Educational Resources Information Center

Reviews the past 25 years of electricity consumption in the United States and considers the implications for the near future. Discusses strategies for energy conservation and provides a student activity for measuring and conserving electric power. (Author/JOW)

Cardon, Phillip L.; Preston, John

2003-01-01

379

Electrical power requirements analysis. Single failure tolerant entry  

NASA Technical Reports Server (NTRS)

The results of an analysis of the orbiter electrical power system for the case of a single failure tolerant (SFT) entry are presented. The analysis was performed using the shuttle electrical power system analysis computer program. It was performed to permit assessment of the capability of the orbiter systems to support the proposed entry configuration and to provide the data necessary to identify potential constraints and limitations. Three contingency modes have been identified which would require an SFT entry. This analysis addresses an SFT entry resulting from the loss of two fuel cell powerplants, while on orbit. The results of the analysis indicate that, even under near optimum conditions, the fuel cell power demand will exceed the tested operating capacity of 16 kw, and that various electrical components may experience voltages below 24 VDC.

Pipher, M. D.; Green, P. A.; Wolfgram, D. F.

1977-01-01

380

Multilevel voltage source inverters with phase shift SPWM and their applications in STATCOM and power line conditioner  

NASA Astrophysics Data System (ADS)

Reactive power compensation and harmonic reduction are two relevant research problems that exist in modern electric power systems. With the advancement of modern power electronics technology in both circuits and devices, new and better solutions are being proposed and applied to solve these two problems. To compensate reactive power, a cascading voltage source inverter with a Phase-Shift, Unipolar SPWM switching scheme is proposed. The main circuit of this inverter is composed of several identical voltage source H-bridge inverters connected in cascade form. Advantages of this scheme include use of identically rated storage capacitors, similarly rated switches and diodes, quick system response to load changes, and easily achievable redundancy. To solve the harmonic reduction problem, the flying capacitor multilevel voltage source inverter is adopted to construct a novel power line conditioner. The Phase Shift SPWM switching scheme is also employed to operate the switches of this inverter. As a result, it is possible to extend the new power line conditioner to distribution systems or industrial applications where voltage usually ranges from 4.16kV to 13.8kV. It is shown that the proposed power line conditioner not only balances the unbalanced load, but simultaneously compensates the reactive power as well.

Liang, Yiqiao

381

Application of modelling and computer simulation for the development of a test setup for calibration of power quality measurement transducers for high voltage networks  

Microsoft Academic Search

T he term power quality is, in general, closely related to the quality of the voltage. Considering the widespread presence of sensitive loads in the electric grid, and the increasing awareness of the consumers concerning the quality of the power supply, the control and measurement of power quality parameters, for instance, harmonics, interharmonics, sags, swells, etc., are increasingly becoming much

HÉDIO TATIZAWA; ERASMO SILVEIRA NETO; GERALDO F. BURANI; ANTÔNIO A. C. A RRUDA; KLEIBER T. SOLETTO; NELSON M. MATSUO

2008-01-01

382

Advanced medium-voltage bidirectional dc-dc conversion systems for future electric energy delivery and management systems  

NASA Astrophysics Data System (ADS)

The distributed renewable energy generation and utilization are constantly growing, and are expected to be integrated with the conventional grid. The growing pressure for innovative solutions will demand power electronics to take an even larger role in future electric energy delivery and management systems, since power electronics are required for the conversion and control of electric energy by most dispersed generation systems Furthermore, power electronics systems can provide additional intelligent energy management, grid stability and power quality capabilities. Medium-voltage isolated dc-dc converter will become one of the key interfaces for grid components with moderate power ratings. To address the demand of medium voltage (MV) and high power capability for future electric energy delivery and management systems, the power electronics community and industry have been reacting in two different ways: developing semiconductor technology or directly connecting devices in series/parallel to reach higher nominal voltages and currents while maintaining conventional converter topologies; and by developing new converter topologies with traditional semiconductor technology, known as multilevel converters or modular converters. The modular approach uses the well-known, mature, and cheaper power semiconductor devices by adopting new converter topologies. The main advantages of the modular approach include: significant improvement in reliability by introducing desired level of redundancy; standardization of components leading to reduction in manufacturing cost and time; power systems can be easily reconfigured to support varying input-output specifications; and possibly higher efficiency and power density of the overall system. Input-series output-parallel (ISOP) modular configuration is a good choice to realize MV to low voltage (LV) conversion for utility application. However, challenges still remain. First of all, for the high-frequency MV utility application, the low switching loss and conduction loss are must-haves for high efficiency, while bidirectional power flow capability is a must for power management requirement. To address the demand, the phase-shift dual-halfbridge (DHB) is proposed as the constituent module of ISOP configuration for MV application. The proposed ISOP DHB converter employs zero-voltage-switching (ZVS) technique combined with LV MOSFETs to achieve low switching and conduction losses under high frequency operation, and therefore high efficiency and high power density, and bidirectional power flow as well. Secondly, a large load range of high efficiency is desired rather than only a specific load point due to the continuous operation and large load variation range of utility application, which is of high importance because of the rising energy cost. This work proposes a novel DHB converter with an adaptive commutation inductor. By utilizing an adaptive inductor as the main energy transfer element, the output power can be controlled by not only the phase shift but also the commutation inductance, which allows the circulating energy to be optimized for different load conditions to maintain ZVS under light load conditions and minimize additional conduction losses under heavy load conditions as well. As a result, the efficiency at both light and heavy load can be significantly improved compared with the conventional DHB converter, and therefore extended high-efficiency range can be achieved. In addition, current stress of switch devices can be reduced. The theoretical analysis is presented and validated by the experimental results on a 50 kHz, 1 kW dc-dc converter module. Thirdly, input-voltage sharing and output-current sharing are critical to assure the advantages of the ISOP modular configuration. To solve this issue, an identically distributed control scheme is proposed in this work. The proposed control scheme, using only one distributed voltage loop to realize both input-voltage and output-current sharing, provides plug-and-play capability, possible high-level fault tolerance, and easy implementatio

Fan, Haifeng

383

Electric power market agent design  

NASA Astrophysics Data System (ADS)

The electric power industry in many countries has been restructured in the hope of a more economically efficient system. In the restructured system, traditional operating and planning tools based on true marginal cost do not perform well since information required is strictly confidential. For developing a new tool, it is necessary to understand offer behavior. The main objective of this study is to create a new tool for power system planning. For the purpose, this dissertation develops models for a market and market participants. A new model is developed in this work for explaining a supply-side offer curve, and several variables are introduced to characterize the curve. Demand is estimated using a neural network, and a numerical optimization process is used to determine the values of the variables that maximize the profit of the agent. The amount of data required for the optimization is chosen with the aid of nonlinear dynamics. To suggest an optimal demand-side bidding function, two optimization problems are constructed and solved for maximizing consumer satisfaction based on the properties of two different types of demands: price-based demand and must-be-served demand. Several different simulations are performed to test how an agent reacts in various situations. The offer behavior depends on locational benefit as well as the offer strategies of competitors.

Oh, Hyungseon

384

Voltage regulator for battery power source. [using a bipolar transistor  

NASA Technical Reports Server (NTRS)

A bipolar transistor in series with the battery as the control element also in series with a zener diode and a resistor is used to maintain a predetermined voltage until the battery voltage decays to very nearly the predetermined voltage. A field effect transistor between the base of the bipolar transistor and a junction between the zener diode and resistor regulates base current of the bipolar transistor, thereby regulating the conductivity of the bipolar transistor for control of the output voltage.

Black, J. M. (inventor)

1979-01-01

385

Test facilities for high power electric propulsion  

NASA Technical Reports Server (NTRS)

Electric propulsion has applications for orbit raising, maneuvering of large space systems, and interplanetary missions. These missions involve propulsion power levels from tenths to tens of megawatts, depending upon the application. General facility requirements for testing high power electric propulsion at the component and thrust systems level are defined. The characteristics and pumping capabilities of many large vacuum chambers in the United States are reviewed and compared with the requirements for high power electric propulsion testing.

Sovey, James S.; Vetrone, Robert H.; Grisnik, Stanley P.; Myers, Roger M.; Parkes, James E.

1991-01-01

386

Electrical power generation by mechanically modulating electrical double layers.  

PubMed

Since Michael Faraday and Joseph Henry made their great discovery of electromagnetic induction, there have been continuous developments in electrical power generation. Most people today get electricity from thermal, hydroelectric, or nuclear power generation systems, which use this electromagnetic induction phenomenon. Here we propose a new method for electrical power generation, without using electromagnetic induction, by mechanically modulating the electrical double layers at the interfacial areas of a water bridge between two conducting plates. We find that when the height of the water bridge is mechanically modulated, the electrical double layer capacitors formed on the two interfacial areas are continuously charged and discharged at different phases from each other, thus generating an AC electric current across the plates. We use a resistor-capacitor circuit model to explain the results of this experiment. This observation could be useful for constructing a micro-fluidic power generation system in the near future. PMID:23403587

Moon, Jong Kyun; Jeong, Jaeki; Lee, Dongyun; Pak, Hyuk Kyu

2013-01-01

387

Computer Power. Part 2: Electrical Power Problems and Their Amelioration.  

ERIC Educational Resources Information Center

Describes electrical power problems that affect computer users, including spikes, sags, outages, noise, frequency variations, and static electricity. Ways in which these problems may be diagnosed and cured are discussed. Sidebars consider transformers; power distribution units; surge currents/linear and non-linear loads; and sizing the power

Price, Bennett J.

1989-01-01

388

Modeling market power in electricity markets: Is the devil only in the details?  

SciTech Connect

Basic approximations of the transmission system are ubiquitous in the literature on modeling competition in electricity markets. Because the main concern of market power is with active power, reactive power and voltage-related issues are commonly neglected, even though they are inherent features of an electrical power system. However, the usefulness of stylized formulations that do not comprise these system elements may be severely limited. (author)

Bautista, Guillermo; Anjos, Miguel F.; Vannelli, Anthony

2007-01-15

389

Electric power annual 1995. Volume I  

SciTech Connect

The Electric Power Annual presents a summary of electric power industry statistics at national, regional, and State levels. The objective of the publication is to provide industry decisionmakers, government policymakers, analysts, and the general public with data that may be used in understanding U.S. electricity markets. The Electric Power Annual is prepared by the Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); U.S. Department of Energy. In the private sector, the majority of the users of the Electric Power Annual are researchers and analysts and, ultimately, individuals with policy- and decisionmaking responsibilities in electric utility companies. Financial and investment institutions, economic development organizations interested in new power plant construction, special interest groups, lobbyists, electric power associations, and the news media will find data in the Electric Power Annual useful. In the public sector, users include analysts, researchers, statisticians, and other professionals with regulatory, policy, and program responsibilities for Federal, State, and local governments. The Congress and other legislative bodies may also be interested in general trends related to electricity at State and national levels. Much of the data in these reports can be used in analytic studies to evaluate new legislation. Public service commissions and other special government groups share an interest in State-level statistics. These groups can also compare the statistics for their States with those of other jurisdictions.

NONE

1996-07-01

390

Power quality load management for large spacecraft electrical power systems  

NASA Technical Reports Server (NTRS)

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

Lollar, Louis F.

1988-01-01

391

Variable voltage portable vaporizer  

US Patent & Trademark Office Database

A portable vaporizer having an electronic control unit electrically coupled to a power source and an atomizer. The electronic control unit utilizes a voltage regulator which allows changes in an output voltage supplied to the atomizer in response to a change in electrical resistance of a potentiometer incorporated therewith.

2014-07-15

392

A new power sensitivity method of ranking branch outage contingencies for voltage collapse  

Microsoft Academic Search

The objective of this paper is to present a powerful procedure for identifying severe single branch outage contingencies with respect to saddle-mode bifurcation induced voltage collapse, given a power system operating point, a load demand forecast, and a generation dispatch. The new power sensitivity ranking algorithm for voltage collapse, called ?\\/MVA sensitivity, provides more accurate \\

Alexander J. Flueck; Renuka Gonella; Jayabharath R. Dondeti

2002-01-01

393

Improved DPC method of VSC to fulfill low voltage ride through requirements in wind power applications  

Microsoft Academic Search

An analysis and improvement of the direct power control method (DPC) for converter feeding generators in wind power applications under disturbed grid voltages is presented. An improved DPC method is derived and described, and its performance is analyzed as well. This improved DPC permits a robust and dynamic control of active and reactive power even under symmetrical and unsymmetrical voltage

Ralf Lohde; Friedrich W. Fuchs

2010-01-01

394

Microarchitectural Simulation and Control of di\\/dt-induced Power Supply Voltage Variation  

Microsoft Academic Search

As the power consumption of modern high-performance microprocessors increases beyond 100 W, power becomes an increasingly important design consideration. This paper presents a novel technique to simulate power supply voltage variation as a result of varying activity levels within the microprocessor when executing typical software. The voltage simulation capability may be added to existing microarchitecture simulators that determine the activities

Ed Grochowski; David Ayers; Vivek Tiwari

2002-01-01

395

Intelligent management of distributed generators reactive power for loss minimization and voltage control  

Microsoft Academic Search

This paper presents an intelligent approach for managing reactive power from a group of distributed generators (DG) connected to low voltage (LV) bus. The objective is to minimize active power losses and keep the voltage profiles in the network within specified limit. This approach finds optimal DG reactive power and optimal tap changer position for main substation transformer every fifteen

Mohd Zamri Che Wanik; Istvan Erlich; Azah Mohamed

2010-01-01

396

Cross-platform validation of notional baseline architecture models of naval electric ship power systems  

Microsoft Academic Search

To support efforts in assessing the relative merit of alternative power system architectures for future naval combatants, the Electric Ship Research and Development Consortium (ESRDC) has developed notional baseline models for each of the primary candidate architectures currently considered, medium-voltage DC (MVDC), conventional 60 Hz medium-voltage (MVAC), and high-frequency medium-voltage (HFAC). Initial efforts have focused on the development of a

Hasan Ali; Roger Dougal; Abdelhamid Ouroua; Robert Hebner; Mischa Steurer; Mike Andrus; James Langston; Karl Schoder; Rob Hovsapian

2011-01-01

397

A novel SOI MESFET by reducing the electric field crowding for high voltage applications  

NASA Astrophysics Data System (ADS)

In this paper, a novel silicon-on-insulator (SOI) metal-semiconductor field-effect transistor (MESFET) is presented by reducing the electric field crowding. The charge distribution in channel modifies by reducing the electric field crowding and results in the breakdown voltage (VBR) improves. To reduce the electric field crowding, a buried field plate (BFP) is employed in the buried oxide of the SOI MESFET and connected to source. DC and frequency response characteristics of the SOI MESFET with BFP (BFP-SOI MESFET) are analyzed via a 2-D numerical simulation and the results are compared with characteristics of a conventional SOI MESFET (C-SOI MESFET) structure. The BFP has outstanding effect on the VBR of the device. The VBR of the proposed BFP-SOI MESFET improves by 84% compared with that of the C-SOI MESFET. Although the saturation drain current of the proposed structure has decreased to a small extent, 37% increase in maximum power density is obtained. In addition, the proposed structure showed an approximately 70% decrease in the gate-drain capacitance (Cgd), which in-turn resulted in 5 dB maximum available gain (MAG) improvement at 2 GHz. As a result of employing the buried field plate, the BFP SOI-MESFET has an outstanding DC and frequency response performance compared with the C-SOI MESFET.

Orouji, Ali A.; Jam, Moein Eslami; Nejaty, Mohammad

2014-08-01

398

Hardware development of Voltage Source Inverter for Hybrid Electric Vehicle  

Microsoft Academic Search

The global desire to reduce the vehicle emissions and improve fuel economy accelerated the development of Hybrid Electric Vehicle (HEV). The technology advancements in the area of electric drive systems, battery technologies, fuel cells and the internal combustion engine (ICE) resulted in highly efficient HEV. In this paper the hardware details of three phase, 50Hz, 6KW, 180 0 conduction mode

S. Umamaheswari; P. R. Thakura; R. K. Keshri

2011-01-01

399

Processing of thermionic power on an electrically propelled spacecraft  

NASA Technical Reports Server (NTRS)

A study to define the power processing equipment required between a thermionic reactor and an array of mercury-ion thrusters for a nuclear electric propulsion system is reported. Observations and recommendations that resulted from this study were: (1) the preferred thermionic-fuel-element source voltages are 23 V or higher; (2) transistor characteristics exert a strong effect on power processor mass; (3) the power processor mass could be considerably reduced should the magnetic materials that exhibit low losses at high frequencies, that have a high Curie point, and that can operate at 15 to 20 kG become avaliable; (4) electrical component packaging on the radiator could reduce the area that is sensitive to meteoroid penetration, thereby reducing the meteoroid shielding mass requirement; (5) an experimental model of the power processor design should be built and tested to verify the efficiencies, masses, and all the automatic operational aspects of the design.

Macie, T. W.

1973-01-01

400

Modular Solar Electric Power (MSEP) Systems (Presentation)  

SciTech Connect

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

Hassani, V.

2000-06-18

401

Power flow management strategies for a local DC Distribution System of More Electric Aircraft  

Microsoft Academic Search

The local DC Power Distribution System of More Electric Aircraft has to be able to sustain bidirectional power flow to and from electromechanical devices. Because the mechanical source (Turbine Engine) is unidirectional, some storage and dissipation systems are necessary to store or\\/and dissipate the returned energy to maintain the DC bus voltage to the reference value. Different power management strategies

He Zhang; Fabien MOLLET; Stefan BREBAN; Christophe SAUDEMONT; Benoît ROBYNS

2010-01-01

402

A methodology for monitoring harmonic distortions in electric power distribution systems  

Microsoft Academic Search

This paper deals with a methodology for the assessment of power quality indices in electric power distribution system, particularly related to voltage harmonic distortions. The paper also presents a proposal for a measurement protocol, a testing procedure to evaluate existing power quality meters and recommendations for the introduction of consistent harmonic assessment indices and parameters to support the implementation of

N. Kagan; E. L. Ferrari; N. M. Matsuo; S. X. Duarte; J. L. Cavaretti; A. Tenorio; L. R. Souza

2002-01-01

403

Energy Management Fuzzy Logic Supervisory for Electric Vehicle Power Supplies System  

Microsoft Academic Search

This paper introduces an energy management strategy based on fuzzy logic supervisory for road electric vehicle, combining a fuel cell power source and two energy storage devices, i.e., batteries and ultracapacitors. The control strategy is designed to achieve the high-efficiency operation region of the individual power source and to regulate current and voltage at peak and average power demand, without

AndrÉ Augusto Ferreira; JosÉ Antenor Pomilio; Giorgio Spiazzi; Leonardo de Araujo Silva

2008-01-01

404

Evaluation of a Superconducting Fault Current Limiter Model for Electric Power System  

Microsoft Academic Search

Fault current limiters (FCLs) are devices for to suppress current in electric power system. The FCL is extensively expected to suppress fault current, particularly required for trunk power systems heavily connected high-voltage transmission lines, such as 500 kV class power system. For this reason, FCLs based on various principles of operation have been developed. Most of the FCLs under development

Takeshi Ohkuma

2003-01-01

405

Multilevel voltage-source converter system with balanced dc voltages.  

National Technical Information Service (NTIS)

A multilevel voltage-source converter system is proposed for high-voltage, high-power applications such as large induction motor drives, back-to-back interconnected power systems, and electrical traction drives. Multilevel voltage-source converters have a...

F. Z. Peng J. S. Lai J. McKeever J. VanCoevering

1995-01-01

406

Module Five: Relationships of Current, Voltage, and Resistance; Basic Electricity and Electronics Individualized Learning System.  

ERIC Educational Resources Information Center

This module covers the relationships between current and voltage; resistance in a series circuit; how to determine the values of current, voltage, resistance, and power in resistive series circuits; the effects of source internal resistance; and an introduction to the troubleshooting of series circuits. This module is divided into five lessons:…

Bureau of Naval Personnel, Washington, DC.

407

Improved voltage disturbance generator for the performance test of the custom power devices  

Microsoft Academic Search

An improved voltage disturbance generator is proposed. To test the performance of the custom power devices such as DVR, SSTS, dynamic UPS, etc., a voltage disturbance generator is necessary. The proposed generator has good features of high reliability, low cost, simple structure, high efficiency, and reduced voltage drop. The main switching device is SCR thyristor, and all the thyristors have

Young-Ho Lee; Hae-Young Park; Eui-Cheol Nho; In-Dong Kim; Tae-Won Chun; Heung-Geun Kim; Nam-Sup Choi

2007-01-01

408

Power flow study and voltage stability analysis for distribution systems with distributed generation  

Microsoft Academic Search

The voltage instability phenomena may occur in distribution networks. The decline of voltage stability level will restrict the increase of load served by distribution companies. Distributed generation (DG) is increasingly drawing great attention of people. The development of DGs will bring new chances to traditional power systems. DGs connected to distribution networks are potential to improve the system voltage stability.

Haiyan Chen; Jinfu Chen; Dongyuan Shi; Xianzhong Duan

2006-01-01

409

Switching minimization and reduction of power loss in a Dynamic Voltage Restorer  

Microsoft Academic Search

The Dynamic Voltage Restorer (DVR) is a custom power device connected in series with the load, which can control the voltage applied to the load by injecting a voltage of arbitrary amplitude, phase and harmonic component into the line. The three-phase four-leg topology of DVR is more advantageous over the other topologies. But it requires higher switching operations of the

Sandeep Joseph; M. K. Mishra; M. Praveen Kumar; S. Sasitharan

2010-01-01

410

New Power Factor Correction AC-DC Converter With Reduced Storage Capacitor Voltage  

Microsoft Academic Search

Most of single-stage power factor correction (PFC) ac-dc converters usually present a high voltage swing on the storage capacitor. That means, high size and cost of the storage capacitor is obtained. The Series Inductance Interval (SII) PFC converters allow reducing cost and size of the storage capacitor since the capacitor voltage is lower than the output voltage and, therefore, the

Antonio Lazaro; Andrés Barrado; Marina Sanz; Vicente Salas; Emilio Olias

2007-01-01

411

A new power flow method for radial distribution systems including voltage dependent load models  

Microsoft Academic Search

This paper presents a simple and efficient method to solve the power flow problem in radial distribution systems. The proposed method takes into account voltage dependency of static loads, and line charging capacitance. The method is based on the forward and backward voltage updating by using polynomial voltage equation for each branch and backward ladder equation (Kirchoff's Laws). Convergence ability

Ulas Eminoglu; M. Hakan Hocaoglu

2005-01-01

412

Voltage Sag Mitigation using NAS Battery-based Standby Power Supply  

Microsoft Academic Search

Advances in industrial automation and manufacturing systems led to the utilization of advanced systems comprise of computers, adjustable speed drives and various industrial control systems that are sensitive to power quality problem, mainly voltage sags. Voltage sag is the reduction of the voltage at a user position with duration of between one cycle and a few seconds caused by motor

Z. F. Hussien; A. B. Ismail; W. C. Lee; A. M. Busrah; M. F. M. Siam

2005-01-01

413

Low Voltage Low Power CMOS Image Sensor with A New Rail-to-Rail Readout Circuit  

Microsoft Academic Search

In this paper a new rail-to-rail pixel readout architecture is proposed to enhance the performance of CMOS image sensor for both low voltage and low power applications. Due to this new readout circuit, the enough input voltage swing under a low supply voltage is achieved and guaranteed for correct successive signal processing. As a consequence, the ability of working under

HWANG-CHERNG CHOW; JEN-BOR HSIAO

2006-01-01

414

Electric power monthly, September 1990. [Glossary included  

SciTech Connect

The purpose of this report is to provide energy decision makers with accurate and timely information that may be used in forming various perspectives on electric issues. The power plants considered include coal, petroleum, natural gas, hydroelectric, and nuclear power plants. Data are presented for power generation, fuel consumption, fuel receipts and cost, sales of electricity, and unusual occurrences at power plants. Data are compared at the national, Census division, and state levels. 4 figs., 52 tabs. (CK)

Not Available

1990-12-17

415

Concerns generated by islanding [electric power generation  

Microsoft Academic Search

The purpose of this article is to discuss islanding operation and to provide end-users with items to consider when determining distributed generation plant and equipment design requirements. Islanding is operating an electric generating plant without an external voltage and frequency reference. Operating in parallel is the opposite of islanding. This article attempts to describe the valid concerns that grid operators

P. L. Villenueve

2004-01-01

416

Spiro-(1,1?)-bipyrrolidinium tetrafluoroborate salt as high voltage electrolyte for electric double layer capacitors  

NASA Astrophysics Data System (ADS)

A novel quaternary ammonium salt based on spiro-(1,1?)-bipyrolidinium tetrafluoroborate (SBP-BF4) has been synthesized and dissolved in propylene carbonate (PC) with 1.5 mol L-1 (M) concentration for electric double-layer capacitors (EDLCs). The physic-chemical properties and electrochemical performance of SBP-BF4/PC electrolyte are investigated. Compared with the standard electrolyte 1.5 M TEMA-BF4 in PC, the novel SBP-BF4/PC electrolyte exhibited much better electrochemical performance due to its smaller cation size, lower viscosity and higher conductivity. The specific discharge capacitance of activated carbon electrode based EDLCs using SBP-BF4/PC electrolyte is 120 F g-1, the energy density and power density can reach 31 kW kg-1 and 6938 W kg-1, respectively, when the working voltage is 2.7 V and current density is 50 mA g-1. The withstand voltage of activated carbon based EDLCs with SBP-BF4/PC electrolyte can reach to 3.2 V, where the stable discharge capacitance and energy density are 121 F g-1 and 43 Wh kg-1, respectively.

Yu, Xuewen; Ruan, Dianbo; Wu, Changcheng; Wang, Jing; Shi, Zhiqiang

2014-11-01

417

Fault-tolerant electrical power system  

NASA Astrophysics Data System (ADS)

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

Mehdi, Ishaque S.; Weimer, Joseph A.

1987-10-01

418

The effect of high voltage, high frequency pulsed electric field on slain ovine cortical bone.  

PubMed

High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network causing the bone strength and toughness augmentation, it apparently did not affect the mineral phase of the cortical bone material. The results also confirmed that the indirect application of high power pulsed electric field at 500 V and 10 kHz through capacitive coupling method was safe and did not destroy the bone tissue construction. PMID:24761375

Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

2014-04-01

419

The Effect of High Voltage, High Frequency Pulsed Electric Field on Slain Ovine Cortical Bone  

PubMed Central

High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network causing the bone strength and toughness augmentation, it apparently did not affect the mineral phase of the cortical bone material. The results also confirmed that the indirect application of high power pulsed electric field at 500 V and 10 kHz through capacitive coupling method was safe and did not destroy the bone tissue construction.

Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

2014-01-01

420

Construction and performance of a high voltage zinc bromine battery in an electric vehicle  

Microsoft Academic Search

This paper describes the design, construction, testing and installation of a 391 volt, 35 kWh zinc bromine battery in an electric vehicle. This research project, was referred to as the “Endura project” and resulted in the construction of the highest voltage zinc bromine battery ever to be used in an electric vehicle. The zinc bromine battery is a high energy

David H Swan; Blake Dickinson; Murali Arikara; Manohar Prabhu

1995-01-01

421

Human perception of electric fields and ion currents associated with high-voltage DC transmission lines  

Microsoft Academic Search

The objective of this study was to assess the ability of humans to detect the presence of DC electric fields and ion currents. An exposure chamber simulating conditions present in the vicinity of high-voltage DC (HVDC) lines was designed and built for this purpose. In these experiments, the facility was used to expose observers to DC electric fields up to

J. P. Blondin; D. H. Nguyen; P. S. Maruvada; J. Sbeghen; D. Goulet; C. Cardinal; M. Plante; W. H. Bailey

1996-01-01

422

Auxiliary Quasi-Resonant DC Tank Electrical Power Converter.  

National Technical Information Service (NTIS)

An auxiliary quasi-resonant DC tank (AQRDCT) power converter with fast current charging, voltage balancing (or charging), and voltage clamping circuits is provided for achieving soft-switched power conversion. The present invention is an improvement of th...

F. Z. Peng

2005-01-01

423

Effect of semiconductor-controlled voltage injection by UPFC and ULTC on power system stability  

NASA Astrophysics Data System (ADS)

Commercial availability of various power semiconductor switches indicates proliferation of power electronic based apparatus in utility power systems. Furthermore, existing power system apparatus, e.g. mechanical phase shifters and mechanical tap changing transformers, will be retrofitted to utilize higher switching speed of semiconductor switches. A group of these apparatus, i.e., unified power flow controller (UPFC), static phase shifter (SPS), under-load tap-changing (ULTC) transformer and static series capacitor (SSC), perform their respective functions by means of injecting series controlled voltages in power systems. This thesis demonstrates that fast series voltage injection, for dynamic power flow regulation, can result in voltage dynamics and even voltage instability. This indicates that fast voltage injection by means of power electronic based apparatus can couple voltage stability and angle stability phenomena. To investigate this coupling phenomena, the voltage dependency of the load must be adequately represented in the load model. The reported studies in this work are based on representing the load by a combination of static and dynamic loads. This thesis primarily investigates impacts of UPFC and semiconductor-controlled ULTC on voltage stability and angle stability phenomena. An eigen analysis approach is used for the studies. The eigen analysis results are validated by digital time-domain simulations using a transient stability software. Both the eigen analysis and the transient stability software tools are tailored to account for angle and voltage stability phenomena.

Alavian Mehr, Alireza

424

An optimized self-powered switching circuit for non-linear energy harvesting with low voltage output  

NASA Astrophysics Data System (ADS)

Harvesting energy from environmental sources has been of particular interest these last few years. Microgenerators that can power electronic systems are a solution for the conception of autonomous, wireless devices. They allow the removal of bulky and costly wiring, as well as complex maintenance and environmental issues for battery-powered systems. In particular, using piezoelectric generators for converting vibrational energy to electrical energy is an intensively investigated field. In this domain, it has been shown that the harvested energy can be greatly improved by the use of an original non-linear treatment of the piezoelectric voltage called SSHI (Synchronized Switch Harvesting on Inductor), which consists in intermittently switching the piezoelectric element on a resonant electrical network for a very short time. However, the integration of miniaturized microgenerators with low voltage output (e.g. MEMS microgenerators) has not been widely studied. In the case of low voltage output, the losses introduced by voltage gaps of discrete components such as diodes or transistors can no longer be neglected. Therefore the purpose of this paper is to propose a model that takes into account such losses as well as a new architecture for the SSHI energy harvesting circuit that limits such losses in the harvesting process. While most of the study uses an externally powered microcontroller for the non-linear treatment, this circuit is fully self-powered, thus providing an enhanced autonomous microgenerator. In particular this circuit aims at limiting the effect of non-linear components with a voltage gap such as diodes. It is shown both theoretically and experimentally that the harvested power can be significantly increased using such a circuit. In particular, experimental measurements performed on a cantilever beam show that the circuit allows a 160% increase of the harvested power compared to a standard energy harvesting circuit, while the classical implementation of the SSHI shows an increase of only 100% of the output power in the classical case.

Lallart, Mickaël; Guyomar, Daniel

2008-06-01

425

Voltage Regulation Performance of a Shunt Active Filter Intended for Installation on a Power Distribution System  

NASA Astrophysics Data System (ADS)

This paper discusses control characteristics of line-voltage regulation by a shunt active filter intended for installation on a power distribution system. Since the power circuit configuration of the active filter is the same as a static synchronous compensator (STATCOM), it is possible to regulate the line voltage by means of controlling an adequate amount of a reactive power. In this case, no harmonic voltage affects a feedback controller for the line-voltage regulation, because the active filter eliminates harmonic components from the line voltage at the installation bus. The dynamic performance is also investigated by computer simulation and experimental results. This paper proposes a new compensation scheme capable of reducing transient voltage fluctuations caused by a phase angle change in the installation bus voltage.

Yamashita, Hiroshi; Jintakosonwit, Pichai; Fujita, Hideaki; Akagi, Hirofumi; Shinohara, Junya; Hakoda, Hirotoshi

426

Automatic voltage imbalance detector  

DOEpatents

A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Bobbett, Ronald E. (Los Alamos, NM); McCormick, J. Byron (Los Alamos, NM); Kerwin, William J. (Tucson, AZ)

1984-01-01

427

Electric power monthly, March 1995  

SciTech Connect

This report for March 1995, presents monthly electricity statistics for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead.

NONE

1995-03-20

428

Advanced electrical power system technology for the all electric aircraft  

NASA Technical Reports Server (NTRS)

The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg. Previously announced in STAR as N83-24764

Finke, R. C.; Sundberg, G. R.

1983-01-01

429

Study on Optimization Strategy for Voltage and Reactive Power Control of Wind Farm  

NASA Astrophysics Data System (ADS)

A method for calculating reactive power limit of wind farm comprised of doubly-fed induction generators (DFIG) is proposed. The reactive power limit of wind farm is the sum of reactive power limit of DFIGs which is calculated by the method considering static stability margin. Based on this, reactive power control of wind farm is discussed and proposed. The proposed reactive power control is divided into different control modes according to power factor of high voltage side in wind farm substation and voltage of low voltage side in point of interconnection(POI). In different control modes, different control objects are applied on reactive power regulation. After reactive power regulation is finished, some reactive power of wind farm should be released. At last, numerical test system is established, the result shows that the proposed method is effective to support voltage of POI

Lu, Q.; Shi, L.; Chen, N.

430

Isolation of an electrical power transmission well  

Microsoft Academic Search

In processes using electrical power to apply heat to a subsurface formation through a transmission well, power losses are reduced by installing in flowlines leading to the well one or more devices that electrically disrupts the flowline and that creates a tortuous flow path for liquids flowing through the device. The parts of the device contacting liquids are either fabricated

Perkins

1985-01-01

431

Well completion for electrical power transmission  

Microsoft Academic Search

There is provided a well completion for electrical alternating current power transmission that minimizes power losses and related corrosion problems. Casing is used both as the electrode and conductor. Most of the conductor portion is made of nonmagnetic metal, for example aluminum, and is electrically insulated both exteriorly and interiorly. The insulation extends below the point where the nonmagnetic metal

Perkins

1984-01-01

432

National electric power grid. [Advantages and disadvantages  

Microsoft Academic Search

Legislation has been introduced in both houses of Congress to establish a national electric power grid. The author favors this controversial legislation for the following reasons: it will (1) reduce the cost of electric energy; (2) become a major energy conservation measure which, through operation of the most-efficient power plants, will reduce the fuel bill of this country; (3) increase

Greber

1977-01-01

433

Electromagnetic pulse and the electric power network  

Microsoft Academic Search

The nuclear electromagnetic pulse (EMP) - electric power system interaction problem is defined. A description of high altitude EMP (HEMP) characteristics, source region EMP (SREMP) characteristics, and magnetohydrodynamics EMP (MHD-EMP) characteristics are presented. The results of initial calculations of EMP induced surges on electric power transmission and distribution lines are presented and compared with lightning induced surges. Potential EMP impacts

K. W. Klein; P. R. Barnes; H. W. Zaininger

1984-01-01

434

Electromagnetic Pulse and the Electric Power Network  

Microsoft Academic Search

This paper defines the nuclear electromagnetic pulse (EMP)-electric power system interaction problem. A description of high altitude EMP (HEMP) characteristics, source region EMP (SREMP) characteristics, and magnetohydrodynamics EMP (MHD-EMP) characteristics are presented. The results of initial calculations of EMP induced surges on electric power transmission and distribution lines are presented and compared with lightning induced surges. Potential EMP impacts on

Kenneth Klein; Paul Barnes; Henry Zaininger

1985-01-01

435

Electric Power Monthly, August 1990. [Glossary included  

SciTech Connect

The Electric Power Monthly (EPM) presents monthly summaries of electric utility statistics at the national, Census division, and State level. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data includes generation by energy source (coal, oil, gas, hydroelectric, and nuclear); generation by region; consumption of fossil fuels for power generation; sales of electric power, cost data; and unusual occurrences. A glossary is included.

Not Available

1990-11-29

436

Low-power programmable high-voltage supply  

NASA Technical Reports Server (NTRS)

Converter is used to energize group of proportional-counter event-detection tubes. Supply is programmed by using output signal of low voltage digital-to-analog converter. Programming voltage ranges from 1.53 to 2.91 V in 127 0.0108 mV steps, and it is used to control converter high voltage output which ranges from 700 to 1,335 V in like number of increments.

Stout, D. F.; Perala, R. A.

1977-01-01

437

The Bulk Power Transmission System of Tokyo Electric Power Company  

NASA Astrophysics Data System (ADS)

In this paper, the history and future prospects of the bulk power transmission system of Tokyo Electric Power Company (TEPCO) are presented. This paper also introduces some technical problems, which has occurred in accordance with the expansion of TEPCO's power system, and measures for ensuring stable power supply.

Kitajima, Takashi

438

The Bulk Power Transmission System of Tokyo Electric Power Company  

Microsoft Academic Search

In this paper, the history and future prospects of the bulk power transmission system of Tokyo Electric Power Company (TEPCO) are presented. This paper also introduces some technical problems, which has occurred in accordance with the expansion of TEPCO's power system, and measures for ensuring stable power supply.

Takashi Kitajima

2008-01-01

439

A novel approach to providing on route power supplies to rural and urban communities in close proximity to the extra high voltage DC transmission line  

Microsoft Academic Search

Extra high voltage DC transmission is planned for the many power corridors of the continental African grid. These lines will traverse the countryside and will pass over many rural and urban communities. These communities will in general have no formal access to grid electrical energy. Access to electrical energy for the basics of light and heat will provide a better

P. Naidoo; N. M. Ijumba

2008-01-01

440

Analysis of Near Field Noise Voltage Caused by Pulse Current on Power Electronics Circuits  

NASA Astrophysics Data System (ADS)

Recently, the design procedure of a power electronics circuit structure is discussed for high power density circuits or thin structure converters. Control circuits of the converter circuit may connect close to the power circuit. When the pulse current flows into the power circuit, it radiates the magnetic field and may generate near field noise voltage to the control circuit. Therefore, it is important for the power electronics circuits to evaluate the near field noise voltage by experiment. This paper shows the measurement results of the near field noise voltage and the electromagnetic force voltage of a small area loop antenna from the 15A, 100kHz buck chopper circuit. Moreover, this paper discusses that the noise voltage may affect the control circuits in the high power density circuits.

Ariga, Zen-Nosuke; Wada, Keiji

441

COMPARISON OF THE DYNAMIC RESPONSE OF WIND POWER GENERATORS OF DIFFERENT TECHNOLOGIES IN CASE OF VOLTAGE DIPS  

Microsoft Academic Search

SUMMARY This paper analyzes the dynamic response of wind power generators in case of voltage dips. When a fault occurs in the network, a voltage dip is applied to the wind power generator common coupling point. Wind power generators are equipped with minimum voltage protections that can trip the unit in case of a long voltage dip to protect both

L. Rouco; F. Fernández-Bernal; J. L. Zamora; P. García-González

2006-01-01

442

SITE ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

The Site Electrical Power System receives and distributes utility power to all North Portal site users. The major North Portal users are the Protected Area including the subsurface facility and Balance of Plant areas. The system is remotely monitored and controlled from the Surface Operations Monitoring and Control System. The system monitors power quality and provides the capability to transfer between Off-Site Utility and standby power (including dedicated safeguards and security power). Standby power is only distributed to selected loads for personnel safety and essential operations. Security power is only distributed to essential security operations. The standby safeguards and security power is independent from all other site power. The system also provides surface lighting, grounding grid, and lightning protection for the North Portal. The system distributes power during construction, operation, caretaker, and closure phases of the repository. The system consists of substation equipment (disconnect switches, breakers, transformers and grounding equipment) and power distribution cabling from substation to the north portal switch gear building. Additionally, the system includes subsurface facility substation (located on surface), switch-gear, standby diesel generators, underground duct banks, power cables and conduits, switch-gear building and associated distribution equipment for power distribution. Each area substation distributes power to the electrical loads and includes the site grounding, site lighting and lightning protection equipment. The site electrical power system distributes power of sufficient quantity and quality to meet users demands. The Site Electrical Power System interfaces with the North Portal surface systems requiring electrical power. The system interfaces with the Subsurface Electrical Distribution System which will supply power to the underground facilities from the North Portal. Power required for the South Portal and development side activities of the subsurface facility will be provided at the South Portal by the Subsurface Electrical Distribution System. The Site Electrical Power System interfaces with the Off-Site Utility System for the receipt of power. The System interfaces with the Surface Operations Monitoring and Control System for monitoring and control. The System interfaces with MGR Site Layout System for the physical location of equipment and power distribution.

E.P. McCann

1999-04-16

443

35. SITE BUILDING 004 ELECTRIC POWER STATION CONTROL ...  

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

35. SITE BUILDING 004 - ELECTRIC POWER STATION - CONTROL ROOM OF ELECTRIC POWER STATION WITH DIESEL ENGINE POWERED ELECTRIC GENERATION EQUIPMENT IN BACKGROUND. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

444

National Maglev initiative: California line electric utility power system requirements  

NASA Astrophysics Data System (ADS)

The electrical utility power system requirements were determined for a Maglev line from San Diego to San Francisco and Sacramento with a maximum capacity of 12,000 passengers an hour in each direction at a speed of 300 miles per hour, or one train every 30 seconds in each direction. Basically the Maglev line requires one 50-MVA substation every 12.5 miles. The need for new power lines to serve these substations and their voltage levels are based not only on equipment loading criteria but also on limitations due to voltage flicker and harmonics created by the Maglev system. The resulting power system requirements and their costs depend mostly on the geographical area, urban or suburban with 'strong' power systems, or mountains and rural areas with 'weak' power systems. A reliability evaluation indicated that emergency power sources, such as a 10-MW battery at each substation, were not justified if sufficient redundancy is provided in the design of the substations and the power lines serving them. With a cost of $5.6 M per mile, the power system requirements, including the 12-kV DC cables and the inverters along the Maglev line, were found to be the second largest cost component of the Maglev system, after the cost of the guideway system ($9.1 M per mile), out of a total cost of $23 M per mile.

Save, Phil

1994-05-01

445

National Maglev initiative: California line electric utility power system requirements  

NASA Technical Reports Server (NTRS)

The electrical utility power system requirements were determined for a Maglev line from San Diego to San Francisco and Sacramento with a maximum capacity of 12,000 passengers an hour in each direction at a speed of 300 miles per hour, or one train every 30 seconds in each direction. Basically the Maglev line requires one 50-MVA substation every 12.5 miles. The need for new power lines to serve these substations and their voltage levels are based not only on equipment loading criteria but also on limitations due to voltage flicker and harmonics created by the Maglev system. The resulting power system requirements and their costs depend mostly on the geographical area, urban or suburban with 'strong' power systems, or mountains and rural areas with 'weak' power systems. A reliability evaluation indicated that emergency power sources, such as a 10-MW battery at each substation, were not justified if sufficient redundancy is provided in the design of the substations and the power lines serving them. With a cost of $5.6 M per mile, the power system requirements, including the 12-kV DC cables and the inverters along the Maglev line, were found to be the second largest cost component of the Maglev system, after the cost of the guideway system ($9.1 M per mile), out of a total cost of $23 M per mile.

Save, Phil

1994-01-01

446

A vehicle electric power generation system with improved output power and efficiency  

SciTech Connect

This paper presents a vehicle electric power generation system with improved output power and efficiency. At low speed, the output power of the system is maximized by using a controllable rectifier to optimize the operating conditions of the alternator. The controllable rectifier is synchronized with the alternator based on the zero-crossing information of the third harmonic voltage. The output power is controlled by shifting the phase voltage with respect to the third harmonic voltage. At high speed, the system output power and efficiency are increased by changing the number of turns of the alternator stator windings. Winding reconfiguration is realized by winding taps and use of two rectifiers and two switches. A proof-of-concept system has been built and tested in the laboratory. The test data show that the new system can increase the output power significantly at both low and high speed. In the speed range in which the alternator is operated most of the time, the winding reconfiguration increases both the output power and efficiency. For the same output power as a production alternator, the winding reconfiguration unit improves the efficiency by 21% (from 47% up to 57%).

Liang, F.; Miller, J.M.; Xu, X.

1999-12-01

447

Analyzing Techniques for Increasing Power Transfer in the Electric Grid  

NASA Astrophysics Data System (ADS)

The worldwide demand for electric energy is slated to increase by 80% between the years 1990 and 2040. In order to satisfy this increase in load, many new generators and transmission lines are planned. Implementations of various plans that can augment existing infrastructure have been hindered due to environmental constraints, public opposition and difficulties in obtaining right-of-way. As a result, stress on the present electrical infrastructure has increased, resulting in congestion within the system. The aim of this research is to analyze three techniques that could improve the power transfer capability of the present electric grid. These include line compaction, use of high temperature low sag conductors and high phase order systems. The above methods were selected as they could be readily employed without the need for additional right-of-way. Results from the line compaction tests indicate that line compaction up to 30% is possible and this increases the power transfer capability up to 53%. Additional advantages of employing line compaction are the reduction in electric and magnetic fields, increase in system stability and better voltage regulation. High temperature low sag conductors that were applied on thermally limited lines were seen to increase the power transfer capability. However, a disadvantage of this technique was that the second most congested line, limits the power transfer capability of the system. High phase (six phase) order system was noted to have several advantages over three phase system such as lower voltage requirement to transfer equal amount of power and lower electric and magnetic field across the right of way. An IEEE 9 and 118 bus test system were used to evaluate the above mentioned techniques.

Dave, Kushal

448

ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT  

SciTech Connect

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

M. Maniyar

2004-06-22

449

Electric power annual 1996. Volume 1  

SciTech Connect

The Electric Power Annual presents a summary of electric power industry statistics at national, regional, and State levels. The objective of the publication is to provide industry decisionmakers, government policy-makers, analysts, and the general public with data that may be used in understanding US electricity markets. The Electric Power Annual is prepared by the Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy. Volume 1--with a focus on US electric utilities--contains final 1996 data on net generation and fossil fuel consumption, stocks, receipts, and cost; preliminary 1996 data on generating unit capability, and retail sales of electricity, associated revenue, and the average revenue per kilowatthour of electricity sold. Additionally, information on net generation from renewable energy sources and on the associated generating capability is included in Volume 1 of the EPA. Data published in the Electric Power Annual Volume 1 are compiled from three statistical forms filed monthly and two forms filed annually by electric utilities. These forms are described in detail in the Technical Notes. 5 figs., 30 tabs.

NONE

1997-08-01

450

Easily disassembled electrical connector for high voltage, high frequency connections  

DOEpatents

An easily accessible electrical connector capable of rapid assembly and disassembly is described wherein a wide metal conductor sheet may be evenly contacted over the entire width of the conductor sheet by opposing surfaces on the connector which provide an even clamping pressure against opposite surfaces of the metal conductor sheet using a single threaded actuating screw. 13 figures.

Milner, J.R.

1994-05-10

451

Easily disassembled electrical connector for high voltage, high frequency connections  

DOEpatents

An easily accessible electrical connector capable of rapid assembly and disassembly wherein a wide metal conductor sheet may be evenly contacted over the entire width of the conductor sheet by opposing surfaces on the connector which provide an even clamping pressure against opposite surfaces of the metal conductor sheet using a single threaded actuating screw.

Milner, Joseph R. (Livermore, CA)

1994-01-01

452

Supply and threshold voltage scaling for low power CMOS  

Microsoft Academic Search

This paper investigates the effect of lowering the supply and threshold voltages on the energy efficiency of CMOS circuits. Using a first-order model of the energy and delay of a CMOS circuit, we show that lowering the supply and threshold voltage is generally advantageous, especially when the transistors are velocity saturated and the nodes have a high activity factor, In

Ricardo Gonzalez; Benjamin M. Gordon; Mark A. Horowitz

1997-01-01

453

Hybrid fiber optic voltage sensor for remote monitoring of electrical submersible pump motors  

NASA Astrophysics Data System (ADS)

We report on the design and experimental evaluation of the hybrid fiber Bragg grating (FBG) piezoelectric voltage sensor developed specifically for remote monitoring of electrical submersible pump (ESP) motors. Unlike a previously reported transducer based on a single piezoelectric element, the voltage rating of the presented device could be as low as 500 V due to the use of a multilayer piezoelectric stack as the primary voltage-to-strain transducer. This enables the use of such sensors across a wider range of ESP applications, which often have subkilovolt voltage ratings. In addition to the design details, we present details of the full characterization of the device, including the hysteresis and temperature-dependence characteristics and discuss ways of eliminating or reducing these effects. We also demonstrate that the sensor can be used to simultaneously measure voltage and temperature.

Dziuda, L.; Niewczas, Pawel; Fusiek, G.; McDonald, James R.

2005-06-01

454

A power-efficient voltage-based neural tissue stimulator with energy recovery  

Microsoft Academic Search

A voltage-based neural stimulator for an implant is fabricated in 1.5?m CMOS. Wireless power transmission and synchronous rectification allow the use of a set of intermediate voltage supplies. This system achieves power consumption 53% lower than traditional current-source stimulators delivering the same charge to electrodes.

Shawn K. Kelly; John Wyatt

2004-01-01

455

Design of a high power pulse voltage generator for electrostatic precipitators using magnetic switching technique  

Microsoft Academic Search

A novel pulsed power supply for pulsed energization of electrostatic precipitators (ESPs) was developed and designed. The new power supply includes a magnetic switch in addition to modern high voltage solid-state switching technology. Load voltage rise times of 2-3 ?s and total pulse widths below 10 ?s, a repetition rate of more than 400 Hz and a pulse amplitude of

L. Heinemann; Kjell Porle; P. Ranstad

1997-01-01

456

Performance improvement of a wind power distribution station using a dynamic voltage restorer  

Microsoft Academic Search

This paper discusses the dynamic voltage restorer (DVR) supported wind power generator connected to the grid to improve the low voltage ride through (LVRT) capability of the grid. The wind power generators are connected to the grid through a feeder to the distribution system and the DVR is connected to the point of common coupling (PCC), where loads are connected.

R. K. Behera; S. K. Parida; Wenzhong Gao

2010-01-01

457

High current, low voltage modular power converter for lead acid battery charging  

Microsoft Academic Search

The submarine lead acid batteries require high current (~8 kA) and low voltage (~10 V) battery chargers because of their high capacities. The need to install the power converters in small place is the driving force for reduced volume and high efficiency. Moreover, the high power lead acid batteries require very low voltage and current ripples and a very high

I. Colak; N. Tuncay

2008-01-01

458

Voltage unbalance vulnerability areas in power systems supplying high speed railway  

Microsoft Academic Search

High speed railway loads fed by the three phase power system represent an important source of unbalance perturbation in the grid. The degree of voltage and current unbalances depends on the train motion, load condition and power system supply configuration. The present paper deals with the identification procedure of a vulnerability area in which the voltage unbalance presents values that

N. Golovanov; G. C. Lazaroiu; M. Roscia; D. Zaninelli

2005-01-01

459

Electric power monthly, May 1996  

SciTech Connect

This publication presents monthly electricity statistics for a wide audience including Congress, Federal and Stage agencies, the electric utility industry, and the general public. Purpose is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. EIA collected the information to fulfill its data collection and dissemination responsibilities in Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

NONE

1996-05-01

460

Flexible Low-Voltage Electric-Double-Layer TFTs Self-Assembled on Paper Substrates  

Microsoft Academic Search

Flexible low-voltage electric-double-layer (EDL) thin-film transistors (TFTs) with a patterned indium-tin-oxide (ITO) channel are self-assembled on paper substrates by only one shadow mask at room temperature. The operation voltage is 1.5 V when a microporous SiO2 solid electrolyte with large EDL capaci- tance is used as the gate dielectric. Such flexible TFTs operate in a full-depletion mode with a high

Aixia Lu; Mingzhi Dai; Jia Sun; Jie Jiang; Qing Wan

2011-01-01

461

Modeling the motion of a toy train powered with a time-dependent applied voltage: Educational implementation and analysis  

NASA Astrophysics Data System (ADS)

We describe the motion of an electric toy train engine that is powered by a time-dependent voltage and travels on a horizontal track. Effects such as friction, the electrically induced torque and electromotive force of the motor, resistance, inductance, and applied voltage are investigated to identify the impact of each on the train's performance. The parameters that describe these effects are experimentally extracted by considering the train's steady-state motion achieved for a constant applied voltage. An equivalent inertia parameter is obtained from transient velocity and current measurements. These parameters are employed in a numerical solution to predict the train's velocity and current for a time-dependent applied voltage. The results are compared with measured values for several independent cases. This analysis has been successfully incorporated into an advanced group project for an introductory course in electricity and magnetism and can be adapted to accommodate students at different levels. Its implementation as an alternative to the traditional laboratory experience is discussed and an assessment of its effectiveness is presented based on the Conceptual Survey in Electricity and Magnetism.

Wick, D. P.; Ramsdell, M. W.

2004-07-01

462

Control of shunt unbalanced power active compensators for reactive and asymmetry elimination in four wire electrical systems using symmetrical components  

Microsoft Academic Search

The paper presents a new method for obtaining the reference currents for a shunt unbalanced power active compensator (SUPAC), working under unbalanced voltages and asymmetrical linear loads. The reference currents are obtained using the unifying theory of electrical power (UTEP), UTEP has been successfully applied to the control of power converters for improving electric quality and optimizes the balance of

Salvador Segui; Francisco Gimeno; Salvador Orts; Rafael Masot; M. Alcaniz

2004-01-01

463

Mini-Scale Power Distribution Network Feeding Trapezoidal-Wave Voltages to Power Electronic Loads with Diode Rectifiers  

NASA Astrophysics Data System (ADS)

This paper proposes a novel three-phase power distribution system feeding trapezoidal voltages to various power electronic loads with diode rectifier front-ends. The network distributes trapezoidal voltages generated by synchronous superposition of wave-shaping voltages onto sinusoidal voltages available from a utility power grid. The power distribution by the trapezoidal voltages allows reducing harmonics of the line currents without electronic switching devices because of a spontaneously widened conduction period of the current waveforms. The reduction of the harmonic currents also contributes to improve total power factor at the load input terminals and efficiency of the power transmission cables. Since the diodes of the rectifiers successively commutate the trapezoidal waves during periods of their flat parts, not only total harmonic distortion of the currents is improved, but also voltage ripple across the dc-buses of the rectifiers can effectively be reduced with less filter capacitors. In addition, the system offers an uninterruptible power supply function by immediately changing its outputs from the wave-shaping voltages to the trapezoidal voltages when interruption occurs in the power grid. In this paper, a prototype of the system is experimentally examined from various angles of operating characteristics and test results are presented to prove feasibility of the proposed system.

Noguchi, Toshihiko; Imoto, Masaru; Sato, Yoshikazu

464

Low-power design technique for ASICs by partially reducing supply voltage  

Microsoft Academic Search

In this paper, we discuss power reduction by comparing two different design techniques targeting low-power ASICs: clustered voltage scaling (CVS) and gate resizing. The CVS is a technique to reduce supply voltage partially, allowing one to reduce power without performance degradation. As a result of application to real gate-array circuits, the CVS reduced power by 30-60% even at dominant wire

Kimiyoshi Usami; Takashi Ishikawa; Masahiro Kanazawa; Hiroko Kotani

1996-01-01

465

Transmission Power Control using Small-Capacity UPFC under Output Voltage Saturation  

NASA Astrophysics Data System (ADS)

This paper presents a fast transmission power control scheme using a UPFC (Unified Power Flow Controller) under the output voltage saturation. For practical use of the UPFC, the fast and stable power response and the reduced power converter capacity are desired. The authors propose the fast and stable control scheme under the output voltage saturation of the reduced capacity UPFC. The effectiveness of the proposed control algorithm of the UPFC has been verified by experiments.

Kuroda, Takeshi; Takeshita, Takaharu; Fujita, Hideki

466

An Autonomous Obstacles Negotiating Inspection Robot for Extra-High Voltage Power Transmission Lines  

Microsoft Academic Search

The purpose of inspection tasks for power transmission lines is to check running state and find damages of extra-high voltage (EHV) power transmission lines equipment. Obviously, inspection tasks are very important for normal operation of power transmission lines. So far, there are two methods for checking power transmission lines. One method is that power transmission line equipment has been checked

Xinglong Zhu; Jiping Zhou; Hongguang Wang; Lijin Fang; Mingyang Zhao

2006-01-01

467

Electrical Model of Balanced AC HTS Power Cable  

NASA Astrophysics Data System (ADS)

The future electricity grid will be more sustainable and it will have more power transmission and distribution capability with more electrical power added from decentralized sources on distribution level and from wind parks and other large sources on transmission level. More interconnections and more underground transmission and distribution will be put up. Use of high temperature superconducting (HTS) power cables provides solutions to many of the future grid problems caused by these trends. In this paper we present an electrical model of a balanced 6 km-long three phase triaxial HTS power cable for the Dutch project being developed by a consortium of Alliander, Ultera™ and TUD. The cable currents in all three phases are balanced by selecting proper twist pitches and insulation thickness. The paper focuses on determining inductances, capacitances and AC losses of the balanced cable. Using the developed model, we also determine the voltage drop as function of the cable length, the neutral current and the effect of the imbalanced capacitances on the current distribution of the Dutch distribution cable. The model is validated and it can be used for accurate simulation of the electrical behaviour of triaxial HTS cables in electrical grids.

Zuijderduin, R.; Chevtchenko, O.; Smit, J. J.; Willén, D.; Melnik, I.; Geschiere, A.

468

Note: Electrical modeling and characterization of voltage gradient in liquid crystal microlenses  

NASA Astrophysics Data System (ADS)

In this work, a novel equivalent electric circuit for modeling liquid crystal microlenses is proposed. This model is focused on explaining a lens behavior at the micrometric scale, using its manufacturing parameters. It suggests an approach to predict the solution of the voltage gradient distribution across a microlens. An interesting feature of the model is that it provides an analytical solution for microlenses with modal and hole-patterned electrode schemes, by a simple software tool. The model flexibility allows lens designers to apply complex waveform signals with different harmonics. The voltage distribution has been tested. The simulated and measured voltage profiles are fairly in agreement.

Urruchi, V.; Algorri, J. F.; Marcos, C.; Sánchez-Pena, J. M.

2013-11-01

469

Multistage and multiobjective formulations of globally optimal upgradable expansions for electric power distribution systems  

Microsoft Academic Search

Electric power distribution systems are the last high voltage link in the chain of production, transport, and delivery of the electric energy, the fundamental goals of which are to supply the users' demand safely, reliably, and economically. The number circuit miles traversed by distribution feeders in the form of visible overhead or imbedded underground lines, far exceed those of all

Mohammad Vaziri Yazdi Pin

2000-01-01

470

Analysis and calculation of lightning-induced voltages in aircraft electrical circuits  

NASA Technical Reports Server (NTRS)

Techniques to calculate the transfer functions relating lightning-induced voltages in aircraft electrical circuits to aircraft physical characteristics and lightning current parameters are discussed. The analytical work was carried out concurrently with an experimental program of measurements of lightning-induced voltages in the electrical circuits of an F89-J aircraft. A computer program, ETCAL, developed earlier to calculate resistive and inductive transfer functions is refined to account for skin effect, providing results more valid over a wider range of lightning waveshapes than formerly possible. A computer program, WING, is derived to calculate the resistive and inductive transfer functions between a basic aircraft wing and a circuit conductor inside it. Good agreement is obtained between transfer inductances calculated by WING and those reduced from measured data by ETCAL. This computer program shows promise of expansion to permit eventual calculation of potential lightning-induced voltages in electrical circuits of complete aircraft in the design stage.

Plumer, J. A.

1974-01-01

471

Electrical voltage manipulation of ferromagnetic microdomain structures in a ferromagnetic/ferroelectric hybrid structure  

NASA Astrophysics Data System (ADS)

We report on electrical bias voltage manipulation of the magnetic domain structures of patterned ferromagnetic Fe dots on a ferroelectric BaTiO3 underlayer using a scanning probe microscope technique. Piezoresponse force microscopy is used to apply local electric field on the Fe dots/BaTiO3 hybrid structure and to map the ferroelectric domain structures simultaneously. Magnetic force microscope observation also demonstrates that the magnetic domain structures of the Fe dots significantly change with the application of voltage at room temperature through the coupling between piezoelectric and magnetostrictive effects, indicating that the Fe dots/BaTiO3 hybrid structure provides a promising basis for controlling micromagnetic domain structures using electric voltage.

Taniyama, T.; Akasaka, K.; Fu, D.; Itoh, M.; Takashima, H.; Prijamboedi, B.

2007-05-01

472

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

473

Dember type voltage and nonlinear series resistance of the optical confinement layer of a high-power diode laser  

NASA Astrophysics Data System (ADS)

An analytical model is developed for the carrier density distribution and the associated Dember type electric field/voltage in the waveguide layer of a high-power semiconductor laser for arbitrary levels of doping and injection. Nonlinear resistance of the waveguide layer is analysed; it is shown that at a very high injection level, doping the waveguide layer leads to almost negligible decrease in its effective resistance.

Avrutin, E. A.; Ryvkin, B. S.

2013-03-01

474