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Control of PWM AC‐to‐DC converters using state‐space and fuzzy‐methods

European Transactions on electrical Power 1995年第5期5卷 301-306页

作者： Krebs, S. Oelert, K. Dr.-Ing. Stephan Krebs (1963) received his Diploma degree in 1990 and his Dr.-Ing. degree in 1994 from the Elektrotechnisches Institut Universitat Karlsruhe/Germany. His main fields of interest are the use of modern time-discrete control methods and parallel signal processing in adjusrable speed drive and power supply systems. In summer 1994. he joined the Power Group of the Department of Electrical and Computer Engineering of the University of Toronto/Canada where he is currently working on industrial controller platform for power applications. (Department of Electrical and Computer Engineering University of Toronto 10 King's College Rd. TorontoiOntario. Canada M5S 1A4 T+416/978-66 18 Fax +416/971-2325) Kai Oelert (1967) received the Electrical Engineering degree from the Elektrotechnisches Institut of the University of KarlsruhdGermany in 1993. He is currently developing software for automatic ticket-wending systems with the Company Scheidt & Bachmann Monchengladbach/Germany. (Scheidt & Bachmann GmbH Breite Str. 132 D-4 1238 Monchengladbach/Germany T+2166/266445 Fax+2166/2666 15)

Adjustable speed drive systems using AC‐machines are often fed by voltage‐source inverters. This paper presents a new strategy to control the line‐side converter. State‐space and fuzzy methods are combined to achieve a control system which includes control limits and the aspects of safety. Experiments with a drive system (30 kW) demonstrate the dynamic and steady‐state behaviour of the control. Copyright © 1995 John Wiley & Sons, Ltd.

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parallel AND DISTRIBUTED TLM COMPUTATION WITH SIGNAL-processing FOR ELECTROMAGNETIC-FIELD MODELING

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INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS 1995年第3-4期8卷 169-185页

作者： SO, PPM ESWARAPPA, C HOEFER, WJR NSERC/MPR Teltech Research Chair in RF Engineering Department of Electrical and Computer Engineering University of Victoria Victoria British Columbia V8W 3P6 Canada Poman So received his B.Sc. degree in computer science and physics from the University of Toronto Toronto Onatario Canada in 1985. He obtained his B.A. Sc. and M.A.Sc. degrees in electrical engineering (summa cum laude) from the University of Ottawa Ottawa Ontario Canada in 1987 and 1989 respectively. Mr So was a research engineer in the University of Ottawa from January 1989 to October 1991 his research interests included CAD techniques of microwave circuits and numerical methods for electromagnetic wave modelling. He specialized in the development of electromagnetic engineering CAD software and successfully implemented a number of electromagnetic wave simulators based on the two-dimensional and three-dimensional transmission-line matrix methods. From August 1990 to February 1991 he accompanied Professor W. J. R. Hoefer to Rome Italy and Sophia Antiopolas France. During that time he implemented a parallel version of the 3D-TLM simulator for the CM-2 Connection Machine using C-Star and X Windows Library. He is a research engineer and a Ph.D. student at the University of Victoria Victoria British Columbia Canada. He ported the 2D- and 3D-TLM simulators to DECmpp 1200 massively parallel computer using MPL C and C++. He also combined OSA90/hope a commercially available microwave CAD program with a 2D-TLM simulation module for geometry optimization using the Datapipe technique of OSA90/hope. Recently he has developed a distributed client-server computing technique for the TLM method this technique could accelerate the TLM simulation by more than an order of magnitude. Channabasappa Eswarappa received the M.Tech. degree in electrical engineering from the Indian Institute of Technology Kanpur India in 1983 and Ph. D. degree from the University of Ottawa Canada in 1990. He worked as an Assistant Executive Engineer and later as

This paper describes the implementation of transmission-line matrix (TLM) method algorithms on a massively parallel computer (DECmpp 12000), the technique of distributed computing in the UNIX environment, and the combination of TLM analysis with Prony's method as well as with autoregressive moving average (ARMA) digital signal processing for electromagnetic field modelling. By combining these advanced computation techniques, typical electromagnetic field modelling of microwave structures by TLM analysis can be accelerated by a few orders of magnitude.

关键词： Mathematical models

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Instrumentation for the Acoustic Thermometry of Ocean Climate (ATOC) prototype Pacific Ocean network

Instrumentation for the Acoustic Thermometry of Ocean Climat...

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OCEANS

作者： B.M. Howe S.G. Anderson A. Baggeroer J.A. Colosi K.R. Hardy D. Horwitt F.W. Karig S. Leach J.A. Mercer K. Metzger L.O. Olson D.A. Peckham D.A. Reddaway R.R. Ryan R.P. Stein K. von der Heydt J.D. Watson S.L. Weslander P.F. Worcester Applied Physics Laboratory University of Washington Seattle WA USA Massachusetts Institute of Technology Cambridge MA USA Scripps Institution of Oceanography University of California San Diego Seattle WA USA Scripps Institution of Oceanography University of California San Diego La Jolla CA USA Communications and Signal Processing Laboratory Electrical Engineering and Computer Science Department University of Michigan Ann Arbor MI USA Woods Hole Oceanographic Institution Seattle WA USA Applied Physics Laboratory University of Washington Woods Hole MA USA

The prototype Pacific Ocean network for the Acoustic Thermometry of Ocean Climate (ATOC) program consists of two shore-cabled acoustic sources, two autonomous vertical hydrophone receiving arrays, and 16 U.S. Navy hydrophone arrays. The sources, receivers, and signaling strategy are designed to be capable of up to 10-megameter transmissions on a routine basis. A new broadband, low-frequency (75 Hz), acoustic source was designed and built by Alliant Techsystems. The bender-bar/barrel-stave transducer is pressure compensated for operation to 1000-m depth. Signal waveform shaping is employed to broaden the effective bandwidth of the source to 37.5 Hz (Q=2; time resolution of 27 ms). Four-element vertical hydrophone arrays are attached to the sources to permit reciprocal transmissions and ambient noise monitoring. Autonomous vertical hydrophone arrays consisting of 40 elements at 35-m spacing (1400-m aperture) were developed to resolve low-order acoustic modes. The autonomous arrays are designed for deployments of up to 1 year, with intermediate readout of the data via ship-recoverable pop-up data modules. The U.S. Navy hydrophone arrays were instrumented with 80486-based data acquisition and processing systems, with communications links for transmitting the data in near real time to a central site for further processing and archiving.

关键词： Instruments Oceans Sonar equipment Acoustic arrays Prototypes Signal design Acoustic transducers Bandwidth Signal resolution Acoustic noise

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Improvement of convergence speed for subband adaptive digital filter using the multirate repeating method

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE 1995年第10期78卷 37-45页

作者： Kiya, H Nishikawa, K Ashihara, K Faculty of Technology Tokyo Metropolitan University Hachioji Japan 192-03 Members Kiyoshi Nshikawa graduated in 1990 from the Department of Electrical Engineering Tokyo Metropolitan University where he completed the Master's Program in 1992 and affiliated with Nippon Steel Co. Computer Systems Laboratory. He was a Research Associate in 1993 in the Department of Elect. Inf. Eng. Tokyo Metropolitan University engaged in research onadaptive signal processing and information source coding. He is a member of the IEEE. Associate Member

The subband adaptive system, where the idea of the filter bank is applied to the adaptive filter, has a feature that a higher-order adaptation can be reduced to lower-order adaptations. The reduction of the order of the adaptive filter is related closely to the number of channels and the decimation ratio. The order of adaptive digital filter (ADF) is decreased greatly when the number of subbands is increased, and the decimation ratio is increased up to the maximum value. Then, however, the number of coefficient-updates per unit time is decreased, which results in the deterioration of the convergence Speed. From such a viewpoint, this paper discusses a method to improve the convergence speed, which is deteriorated in the subband adaptive system, due to the decimation. The idea of the proposed method is to utilize effectively the data which have been discarded in the decimation process and to improve the convergence speed. It is called the multirate repeating method. As the first step, the multirate repeating method is applied to the conventional subband adaptive system and the convergence speed is improved. Then a subband adaptive system is introduced in which the multirate repeating method can be utilized more effectively. As a result, a faster convergence is realized while retaining the ADF order-reduction effect, which is an advantage of the subband adaptive system.

关键词： adaptive signal processing subband adaptive system multirate repeating method rational decimation

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New method to control cascaded doubly‐fed machines in the state space

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European Transactions on electrical Power 1995年第1期5.0卷 55-61页

作者： Krebs, S. Dr.-Ing. Stephan Krebs (1963) received his Diploma degree in 1960 and his Dr.-Ing. degree in 1994 from the Elektrotechnisches Institut Universitat Karlsruhe/Germany. His main fields of interest are the use of modem time-discrete control methods and parallel signal processing in adjustable speed drive and power supply systems. In summer 1994 he joined the Power Group of the Department of Electrical and Computer Engineering of the University of Toronto/Canada where he is currently working on industrial controller platform for power applications. (Department of Electrical and Computer Engineering University of Toronto 10 King's College Rd. Toronto/Ontario Canada M5S 1A4 T +4 1 6/9 78-66 18 Fax +4 1 6/9 7 1-23 25)

The cascaded doublyfed machine consists of two separate induction machines which are interconnected by their rotor windings. This paper presents a general control structure for such machines, based on the principle of the field‐oriented control. An adjustable speed drive operating in subsynchronous mode is compared with an asynchronous machine‐drive system, and its advantages are shown. State‐space control methods are used to get a stable behaviour over a wide speed range. Copyright © 1995 John Wiley & Sons, Ltd.

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Multiagent fault‐diagnosis expert system in power systems

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European Transactions on electrical Power 1995年第5期5卷 341-347页

作者： Wang, J.P. Trécat, J. Dr. Jianping Wang is a doctor fellow in the Faculte Polytechnique de Mons in Belgium. His current research field is parallel processing applications in power systems. Dr. Wang obtained his BS degree from Southwest Jiaotong University in P.R. Chinain 1982. From 1982 to 1990 he was appointed as an assistant lecturer. lecturer and associate professor respectively in the electrical engineering department of Southwest Jiaotong University. He obtained his Ph.D in the FacultC Polytechnique de Mons in July of 1993. (BD Dolez 3 1 FPMS B-7000 Mons Belgium T +32-65/37 41 87 Fax +32-65/37 43 00) Professor J. Trécat is a director in the power system laboratory in the Faculty Polytechnique de Mons. He obtained his Ph.D in the University of Manchester Institute of Science and Technology(UM1ST) in U.K. in 1970. He has been working in the fields of power system automation artificial intelligence application and computer vision in the Facult6 Polytechnique de Mons since 1970. He is a senior member of IEEE and he has made much contribution both in electrical engineering education and research. (BD Dolez 3 I FPMS B-7000 Mons T +32-651374185. Fax +32-6513743 00)

In order to solve the speed problem and shallow reasoning problem met in current research in fault diagnosis expert system, this paper presents a model based parallel fault diagnosis expert system for energy management systems (EMS). The Petri net model, which corresponds to the relationship between power system components and their protection systems, has been used for the inference in fault diagnosis. A multiagent parallel processing expert system, which is based on five transputers in Sun workstation, has been built for fault diagnosis purposes. The test results show that this expert system is not only fast but also has better performances. Copyright © 1995 John Wiley & Sons, Ltd.

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ANALYTICAL MODELING OF PLASMA IMMERSION ION-IMPLANTATION TARGET CURRENT USING THE SPICE CIRCUIT SIMULATOR

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B

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JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B 1994年第2期12卷 833-837页

作者： EN, W CHEUNG, NW Plasma Assisted Materials Processing Laboratory Department of Electrical Engineering and Computer Sciences University of California Berkeley California 94720

Plasma immersion ion implantation applies a series of negative high-voltage pulses to a target immersed in a plasma. An analytical model of the currents and potentials induced before, during, and after the negative bias in a planar geometry is presented. The effect of multiple pulses on the results is also studied. The model determines the time-varying ion current, electron current, total current, total dose, and sheath thickness for a piecewise linear voltage pulse. The sheath collapse is found to be important for high repetition rate pulses. Implementation of the model is done in SPICE, a circuit simulator. Comparison with experimental data has demonstrated the accuracy of the model.

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Velocity tuned generalized Sobel operators for multiresolution computation of optical flow

Velocity tuned generalized Sobel operators for multiresoluti...

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The 1994 1st IEEE International Conference on Image processing

作者： Gökstorp, M. Danielsson, P.-E. Image Processing Laboratory Computer Engineering Division Department of Electrical Engineering Linköping University LinköpingS-581 83 Sweden

Optical flow computation may be divided into four processing steps where the first is extraction of image features suitable for flow estimation. Using a generalization of the basic flow constraint it is possible to estimate flow vectors from a set of feature images obtained from the input image sequence. Generalized Sobel operators provide a suitable set of feature extraction operators. The set of five filters up to second order provides good approximations of ideal edge and line detectors. A review of spatial and frequency constraints on optical flow suggests a multiresolution approach to optical flow where the initial feature extractors consists of velocity tuned operators. We show that two-dimensional generalized Sobel operators may be extended to spatio-temporal velocity tuned filters for optical flow estimation. Experimental results compare well to existing methods. © 1994 IEEE.

关键词： Optical flows

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Static program decomposition among machines in an SIMD/SPMD heterogeneous environment with non-constant mode switching costs

Static program decomposition among machines in an SIMD/SPMD ...

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1995 Heterogeneous Computing Workshop, HCW 1994

作者： Watson, Daniel W. Antonio, John K. Siegel, Howard Jay Atallah, Mikhail J. Department of Computer Science Utah State University LoganUT84321-4205 United States Parallel Processing Laboratory School of Electrical Engineering Purdue University West LafayetteIN47907-1285 United States Computer Sciences Department Purdue University West LafayetteIN47907-1398 United States

ISBN: (纸本)0818655925

The problem of minimizing the execution time of programs within a heterogeneous environment is considered. Different computational characteristics within a parallel algorithm may make switching execution from one machine to another beneficial;however, the cost of switching between machines during the execution of a program must be considered. This cost is not constant, but depends on data transfers needed as a result of the move. Therefore, determining a minimum-cost assignment of machines to program segments is not straightforward. A previously presented Block-Based Mode Selection (BBMS) approach is used as a basis to develop a heuristic method for assigning machines to program segments of data-parallel algorithms. Simulation results of parallel program behavior using the heuristic indicate that good assignments are possible without resorting to exhaustive search techniques. © 1994 IEEE.

关键词： Heuristic methods

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TRENCH DOPING CONFORMALITY BY PLASMA IMMERSION ION-IMPLANTATION (PIII)

IEEE ELECTRON DEVICE LETTERS

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IEEE ELECTRON DEVICE LETTERS 1994年第6期15卷 196-198页

作者： YU, C CHEUNG, NW Plasma Assisted Materials Processing Laboratory Department of Electrical Engineering and Computer Sciences University of California Berkeley CA USA Dept. of Electr. Eng. & Comput. Sci. California Univ. Berkeley CA USA

Plasma immersion ion implantation (PIII) is a technique which can be used to conformally dope sidewalls of Si trenches. Using junction staining techniques and subsequently calibrating the observed stained depth to measured dose, dopant distributions inside Si trenches with aspect ratios ranging from 1 to 12 are studied for various bias voltages from 5 to 20 kV. Unlike conventional collimated beam implantation, PIII was able to conformally dope all aspect ratios studied with no evidence of abrupt discontinuities in the dopant distribution along the trench surface as a result of beam shadowing by trench geometry. Furthermore, it is shown that the higher implant biases results in more directional trajectories. Thus, dopant distributions along irregular geometries can be controlled by PIII process conditions.

关键词： Doping Plasma immersion ion implantation Ion implantation Surface topography Plasma applications Plasma measurements Voltage Implants Plasma materials processing Geometry

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