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Measurements of power and current components in unbalanced and distorted three‐phase systems

European Transactions on electrical Power 1993年第1期3卷 75-83页

作者： Andria, G. Salvatore, L. Savino, M. Trotta, A. Dr. Gregorio Andria (1956) AEI received the M. S. degree in Electrical Engineering from the State University of Bari/Italy in 1981 and the Ph. D. degree in Electrical Engineering in 1987 from the same University. From 1981 to 1983 he was working in the Electrotechnics and Electronics Department of the University of Bari as a member of the research team on electrical measurements. From 1984 to 1986 he was a Doctoral Fellow and currently he is a researcher in the same department. His research interests are in the fields of electrical and electronic measurements on components and systems including digital measurements for the analysis of electrical quantities in non-sinusoidal systems and the design of integrated optical sensors for measurement and control of non-electrical physical quantities. (Department of Electrotechnics and Electronics Faculty of Engineering polytechnic of Bovia E. Orabona 4 1-70125 Bari. Italy T +3980/242266 Fax + 3980/242410) Prof. Luigi Salvatore (1945) AEI received the degree in electrical engineering from the University of Bari/Italy in 1970. Since 1976 he has worked in the Electrotechnical and Electronic Department of the same University as a member of the research team on electrical machines. From 1983 to 1987 he was a researcher of electrical machines in the same department. Since 1987 he has been an Associate Professor of electrical machines at the University of Bari. At the present time his research interests include the control monitoring and diagnostics of AC drives and the areas of signal processing anddigital measurements on power electronics systems. (Department of Electrotechnics and Electronics Faculty of Engineering Polytechnic of Bari via E. Orabona 4 I-70125 Bari Italy T + 3980/242258 Fax + 3980/242410) Prof. Mario Savino (1947) AEI received the degree in Electrical Engineering from the University of Barif Italy in 1971. Since then he has been working in the Electrotechnical Institute of Bari until 1973 as researcher from 1973 to 1982 as Assistant Profe

The paper deals with the instantaneous power theory in three‐phase circuits by using the instantaneous time phasors of voltage and current. Particularly it is shown that the instantaneous components of the current time‐phasor in a rotating reference frame p‐q, oriented in such a way that the instantaneous voltage time‐phasor points to the p‐axis direction, represent the active and reactive currents. These components give rise to instantaneous real and imaginary powers, respectively. The spectral analysis of the above‐mentioned time‐phasors gives the harmonic symmetrical components of positive and negative sequence of voltage and current three‐phase systems. The line‐by‐line product of the voltage sequence spectrum by the complex conjugate of the current sequence spectrum gives the DC components of the instantaneous real and imaginary powers. The paper shows also that the instantaneous active and reactive currents are different from those defined on grounds of the Fryze's theory, which can be determined from the voltage and current sequence spectra. Copyright © 1993 John Wiley & Sons, Ltd.

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ACCURACY REQUIREMENTS FOR MEASUREMENT systems WITH UNIFORM AND NORMAL ERRORS

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NAVAL ENGINEERS JOURNAL 1993年第1期105卷 66-69页

作者： SNOW, JM STUCKMAN, BE USHER, JS Jeffrey M. Snow:received his B.S. degree in mechanical engineering from the University of Washington in 1977. He has worked at Boeing Commercial Aircraft Company and Puget Sound Naval Shipyard. Since 1985 he has been at Naval Surface Warfare Center Crane Division (NSWCC). From 1987 to 1990 he was in charge of quality assurance configuration management and reliability for Aegis (SPY-1 and Mk-99) microwave tubes. He currently is in the Radar System Branch at NSWCC. He is a member of ASQC and ASME. His areas of interest include the use of statistics in process improvement efforts and objectively rating and rewarding suppliers for better quality. Bruce E. Stuckman:holds a Ph.D. degree in systems engineering from Oakland University where he also obtained M.S. and B.S. degrees in electrical and computer engineering. In 1992 Dr. Stuckman obtained his J.D. from the University of Louisville where he graduated cum laude. He is currently an associate in the patent and computer law department of Brooks & Kushman a law firm specializing in intellectual property and technology related causes. Prior to this he was an associate professor of both electrical engineering at the University of Louisville and a member of the Research Advisory Board of the South Central Bell Telecommunications Research Center. Dr. Stuckman is the author of over 75 published works in a variety of research areas including global optimization algorithms control systems communication and telecommunication systems and instrumentation electronics. He has served as a technical consultant to such organizations as Control Data Corporation General Electric General Motors Research Laboratories Gulf & Western AT&T Bell Laboratories ARCO Research and Technical Services and the U.S. Government and has been a frequent lecturer at national and international symposia. He is a senior member of IEEE and a member of ASNE Eta Kappa Nu Tau Beta Pi Sigma Xi and Phi Kappa Phi. John S. Usher Ph.D. P.E.:is an assistant professor of industrial engineering

Accuracy requirements are usually determined as a percentage of the specification range of the measured part or process. Setting accuracy requirements in this manner results in a wide and unpredictable range of false rejection and acceptance probabilities. This causes extra costs due to either: 1) over specification of measurement systems accuracy requirements;2) time, effort, retesting, and resolution of false rejections;or 3) system degradation caused by false acceptance of out-of-specification parts. Achieving a consistent and known risk of false acceptance is only possible by considering the measured process C(pk), the process's mean in relation to the center of the specification range, and the measurement system error distribution. This paper presents a method for calculating the probabilities of false rejection and false acceptance for a normal process which is measured with, alternately, uniform and normally distributed error. It is shown that under most conditions uniform error causes 20% to 30% higher false rejection and acceptance probabilities. Thus, knowledge of measurement error distribution could provide lower total production cost.

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HYBRID CODERS WITH MOTION COMPENSATION

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MULTIDIMENSIONAL systems AND SIGNAL PROCESSING 1992年第2-3期3卷 241-266页

作者： CHEN, CF PANG, KK 1. Video Communication Group Department of Electrical and Computer Systems Engineering Monash University 3168 Clayton Victoria Australia

This paper investigates analytically the effects of motion compensation in a coder based on the observed properties of motion-compensated frame difference (MCFD) signals. The AR(1) processes with a given pixel-to-pixel autocorrelation coefficient will be used to model the interframe images. For interframe motion, each image is allowed to have both moving and nonmoving parts, with the moving parts executing a range of translational motion. From this mathematical model, the statistical characteristics of MCFD signals am derived. Motion compensation gain, 2-D intraframe transform gain, and hybrid gain are next evaluated to ascertain their suitability for the coding process. Experimental results on the Trevor sequence seem to confirm the model and conform with its analytical results.

关键词： MOTION COMPENSATION MOTION ESTIMATION INTERFRAME CODING INTRAFRAME CODING HYBRID CODING CORRELATION MATRIX DISTORTION RATE FUNCTION

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Control of ω-automata, church’s problem, and the emptiness problem for tree ω-automata 5th

Control of ω-automata, church’s problem, and the emptiness...

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5th Workshop on computer Science Logic, CSL 1991

作者： Thistle, J.G. Wonham, W.M. Department of Electrical Engineering and Computer Sciences University of California BerkeleyCA94720 United States Systems Control Group Department of Electrical Engineering University of Toronto TorontoONM5S 1A4 Canada

ISBN: (纸本)9783540557890

Church’s problem and the emptiness problem for Rabin automata on infinite trees, which represent basic paradigms for program synthesis and logical decision procedures, are formulated as a control problem for automata on infinite strings. The alphabet of an automaton is interpreted not as a set of input symbols giving rise to state transitions but rather as a set of output symbols generated during spontaneous state transitions;in addition, it is assumed that automata can be "controlled" through the imposition of certain allowable restrictions on the set of symbols that may be generated at a given instant. The problems in question are then recast as that of deciding membership in a deterministic Rabin automaton’s controllability subset - the set of states from which the automaton can be controlled to the satisfaction of its own acceptance condition. The new formulation leads to a direct, efficient and natural solution based on a fixpoint representation of the controllability subset. This approach combines advantages of earlier solutions and admits useful extensions incorporating liveness assumptions. © Springer-Verlag Berlin Heidelberg 1992.

关键词： Forestry

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Adaptive neural network control of fes-induced cyclical lower leg movements

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Annual Review in Automatic Programming 1992年 17卷 25-30页

作者： S.H. Stroeve H.M. Franken P.H. Veltink W.T.C. van Luenen Biomedical Engineering Division Department of Electrical Engineering University of Twente The Netherlands Control Systems and Computer Engineering Group Department of Electrical Engineering University of Twente The Netherlands

As a first step to the control of paraplegic gait by functional electrical stimulation (FES), the control of the swinging lower leg is being studied. This paper deals with a neural control system, that has been developed for this case. The control system has been tested for a model of the swinging lower leg using computer simulations. The neural controller was trained by supervised learning (SL) and by backpropagation through time (BTT). The performance of the controller with random initial weights was poor after training with BTT and fair after SL. BTT training of the neural controller with weights, which had been initialized by SL, resulted in good control. Training with BTT thus improved the performance of the controller that initially had been trained by SL. An adaptive neural control system based on BTT has been proposed and partially tested. The controller adapted relatively fast to the change of an important model parameter.

关键词： Adaptive control backpropagation through time biocybemetics functional electrical stimulation neural nets nonlinear control systems self-adapting systems

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Adaptive Neural Network Control of Fes-Induced Cyclical Lower Leg Movements

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IFAC Proceedings Volumes 1992年第10期25卷 25-30页

关键词： Adaptive control backpropagation through time biocybernetics functional electrical stimulation neural nets nonlinear control systems self-adapting systems

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A framework for performance engineering during information system development 4th

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4th International Conference on Advanced Information systems engineering, CAiSE 1992

作者： Opdahl, Andreas L. Sølvberg, Arne The University of Trondheim Norway Department of Informatics Faculty of Nature Sciences College of Arts and Science Norway Information Systems Group Department of Electrical Engineering and Computer Science The Norwegian Institute of Technology Norway

ISBN: (纸本)9783540554813

Software performance engineering aims at predicting and improving the performance of applications during development and in production. This paper presents a framework for performance engineering of information systems with emphasis on parameter estimation support. The need for performance engineering of information systems is discussed. Views of information system and performance modelling are presented. It is shown how application specifcations can be extended with performance annotations. The resulting framework is applied to predict and improve the performance of projected applications during development. Sensitivity analysis is supported to point out performance bottlenecks in the application and suggest which parameters to estimate with most care. Target platform modelling is provided to relieve the information system developer from assessing the performance of the target platform and operating system software. The framework is realised in terms of the PrM language for software specification. Finally, some conclusions are offered. © Springer-Verlag Berlin Heidelberg 1992.

关键词： Information systems

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Synthesis of high-speed A/D converter architectures with flexible functional simulation capabilities

Synthesis of high-speed A/D converter architectures with fle...

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1992 IEEE International Symposium on Circuits and systems, ISCAS 1992

作者： Vital, João C. Franca, José E. Integrated Circuits and Systems Design Group Electrical and Computer Engineering Department Instituto Superior Técnico AV4. Rovisco Pais Lisboa Codex1096 Portugal

ISBN: (纸本)0780305930

A CAD tool for high-level synthesis of high-speed AID converter architectures is described, which includes a flexible functional simulation capability taking into account the most relevant electrical parameters. By using the flash quantizer and the charge-redistribution MDAC blocks as the only mixedsignal functional primitives, this tool is capable of synthesizing multiple architectures, including the flash, subranging, two-step flash and pipelined AID converters. © 1992 IEEE.

关键词： High level synthesis

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Synthesis of high-speed A/D converter architectures with flexible functional simulation capabilities

Synthesis of high-speed A/D converter architectures with fle...

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IEEE International Symposium on Circuits and systems (ISCAS)

作者： J.C. Vital J.E. Franca Electrical and Computer Engineering Department Integrated Circuits and Systems Design Group Instituto Superior Técnico Lisboa Portugal Electrical and Computer Engineering Department Integrated Circuits and Systems Design Group Instituto Superior Técnico Lisboa Portugal

A CAD tool for high-level synthesis of high-speed analog-to-digital (A/D) converter architectures is described, which includes a flexible functional simulation capability taking into account the most relevant electrical parameters. By using the flash quantizer and the charge-redistribution multiplying digital-to-analog converter (MDAC) blocks as the only mixed-signal functional primitives, this tool is capable of synthesizing multiple architectures, including the flash, subranging, two-step flash and pipelined AID converters. The tool analyzes and determines the required high level building block specifications, based on functional models which accurately describe the dominant poles of the electrical behavior of the lowest-level building-blocks, namely arrays of switches, arrays of capacitors, resistor strings, operational amplifiers and comparators. A functional simulation based on such models is included.< >

关键词： Voltage Capacitors Computational modeling Circuit simulation Signal synthesis Switches Resistors Integrated circuit synthesis Design engineering Design automation

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Image interpolation based on image statistics: a case study

Image interpolation based on image statistics: a case study

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IEEE Region 10 International Conference TENCON

作者： T. Sikora P. Richardson Video Communications Group Department of Electrical and Computer Systems Engineering Monash University Clayton VIC Australia

Two novel approaches to image interpolation aimed at video service interworking, layered image coding, and image zooming are discussed. Compared to conventional interpolation filters used for image interpolation, the schemes proposed take advantage of prior knowledge of image statistics to enhance their performance. Both methods, inverse Wiener filtering (IWF) and vector interpolation (VI), use image training sequences to estimate optimal interpolation parameters. While IWF has online capabilities for parameter estimation, VI parameters need to be designed in computer intense offline optimization procedures. Both IWF and VI methods achieve superior performance compared to standard linear interpolation filters in terms of signal-to-noise ratio of the interpolated images, as well as entropy of the residual errors.< >

关键词： Interpolation Statistics Wiener filter Parameter estimation Image coding Vectors Design optimization Nonlinear filters Signal to noise ratio Entropy

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