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Expert system for energizing bulk power systems after a blackout

EUROPEAN TRANSACTIONS ON ELECTRICAL power 1997年第1期7卷 19-26页

作者： Markovic, ML [?]Milond L. Markovic (1960) received the Dipl.-Ing. and M.Sc. degrees in electrical engineering from the University of Beognd in I984 and 1990. respectively. From 1985 to 1991 he was at the Institute “Mihajlo Pupin” Beognd. In 1991 he joined the Austrian Electricity Board (Verbund) in its central dispatching department. His main interests are application of Operations Research methods and intelligent systems to power system control and operation. (herreichische Elektrizitiitswirtschafts-AG (Verbund). Am H of 6 a. A-IOIO Wien. Austria. Tel +43 11531 13-2368 Fax +43 1/5113-23 16. E-mail: markovic@verbund.co.at)

In this paper an expert system for energizing the hydro-dominated Austrian bulk power system after a blackout is presented. According to general restoration guidelines and operating procedures, the expert system computes the restoration schedule (as a sequence of events)for the presumed blackout (i. e. non-available elements are defined). The restoration schedule is concluded using a discrete event simulator where all substations are modelled at element level. The dispatcher is guided by check lists to follow this restoration schedule and the switching instructions are proposed. Subsequent faults during the restoration result in a revision of the restoration schedule. This expert system has been realized with the help of the expert system fool KEE, and is in use as a stand-alone program. Further integration within the energy management system is under way.

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Mathematical foundations of the instantaneous power concepts: A geometrical approach - Mathematical foundations of the instantaneous power concepts: An algebraic approach - Reply

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EUROPEAN TRANSACTIONS ON ELECTRICAL power 1996年第5期6卷 314-314页

作者： Willems, JL Cristaldi, L Ferrero, A [?]From the Massachusetts Institute of Technology Cambridge and the Ph. D. degree in applied science from the University of Gent in 1963 1964 and 1967 respectively. In 1964 he joined the Engineering Faculty of the University of Gent where he is presently Professor of Electrical Engineering. In 1970 he was on leave at the Division of Engineering and Applied Physics of Harvard University Cambridge Mass./USA. In 1982 he was a Visiting Professor at the Universiti Nationale du Rwanda (Central Africa). His teaching and research interests include power system analysis and control system stability theory. From 1988 to 1992 he was Dean of the Engineering Faculty of the University of Gent. Since October 1993 he has been Rectorofthe University. (University of Gent Technologiepark-Zwijnaarde 9 B-9052 Gent (Zwijnaarde)/ Belgium T + 329/2645653 Fax + ***)

In this paper a mathematical formalism, based on a geometrical approach, is proposed for defining the concepts of instantaneous active and instantaneous reactive power. Use is made of the dot product and the cross product for three-dimensional vectors. The relationship with the analysis proposed by Akagi et al. and by Ferrero and co-authors is discussed in detail. In particular it is shown that the proposed formalism is well suited to deal with three-phase currents and voltages with zero-sequence components.

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A neural-net based short term load forecasting using moving window procedure

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INTERNATIONAL JOURNAL OF ELECTRICAL power & ENERGY systemS 1995年第6期17卷 391-397页

作者： Djukanovic, M Ruzic, S Babic, B Sobajic, DJ Pao, YH Institute ‘Nikola Tesla’ Belgrade Yugoslavia Electric Power Utility cf Serbia Belgrade Yugoslavia Power System Control EPRI Palo Alto CA 94304 USA Departments of Electrical Engineering and Computer Science Case Western Reserve University USA AI WARE Inc. Cleveland OH 44106 USA

An improved neural-net approach based on a combined unsupervised/supervised learning concept is proposed. A 'moving window' procedure is applied to the most recent load and weather information for creating training set data base. A forecasting lead time that varies from 16 hours to 88 hours is introduced to produce the short term electric load forecasting that meets requirements of real electric utility operating practice. The unsupervised learning (UL) is used to identify days with similar daily load patterns. A feed forward three-layer neural net is designed to predict 24-hour loads within the supervised learning (SL) phase. The effectiveness of proposed methods is demonstrated by comparison of forecasted hourly loads in every single day during 1991 with data realized in the same period in the Electric power Utility of Serbia (EPS). A better choice of input features and more appropriate training set selection procedure allow significant improvement in forecasting results comparing with our previous UL/SL concept characterized by a fixed neural-net structure and absence of re-training procedure. The improvement is illustrated by reduction of average error in daily energy forecasting for 0.83% and reduction of 90th percentile of 2.04%.

关键词： neural-nets load forecasting unsupervised supervised learning

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SHIPS SERVICE ELECTRIC-power - ENHANCED SURVIVABILITY VIA EARLY DETECTION OF INCIPIENT CABLE FAULTS

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NAVAL ENGINEERS JOURNAL 1993年第3期105卷 78-84页

作者： WILLIAMS, SE RUSSELL, BD Stephen E. Williams:graduated summa cum laude from Texas A&M University with a B.S. degree in electrical engineering in 1991. He is still at Texas A&M while completing an M.S. in E.E. with special interest in low voltage (less than 600 V) network protection. Mr. Williams is a National Science Foundation Graduate Research Fellow and a student member of the IEEE. B. Don Russell:received B.S. and M.E. degrees in electrical engineering at Texas A&M University. He holds a Ph.D. from the University of Oklahoma in power system engineering. Dr. Russell is a professor of electrical engineering and director of the Power System Automation Laboratory of the Electric Power Institute Texas A&M University. His research centers on the use of advanced technologies to solve problems in power system control protection and monitoring. He is the recipient of several awards and patents for advanced digital technology applications. Dr. Russell is a member of the IEEE Power Engineering Society Executive Board. He also chairs the annual TAMU Conference for Protective Relay Engineers and the Fault and Disturbance Analysis Conference. Dr. Russell is a fellow of the IEEE a Registered Professional Engineer and a member of the Texas Society of Professional Engineers.

Researchers at Texas A&M Universitv have studied the effects of battle damage on ship power distribution cables, with particular interest in damaged cables which did not fail immediately. The electrical signatures of partiallv damaged cables are significant and are detectable with advanced protection methods used on terrestrial power svstems. Findings show that the damaged cable signatures are similar to those of arcing faults on terrestrial power distribution svstems, which can be reliably detected using an on-line expert svstem [1,2,3]. The implications of these findings are significant. Since the abilitv of a damaged ship to right through an encounter is entirelv dependent on keeping operational its various systems which rely on electric power, the ability to automatically detect and re-route power around damaged regions is imperative. By identifving the characteristics of failing power cables before catastrophic failure occurs, the protection process can be integrated into the ship automatic control system. The overall result is a more survivable ship.

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A kalman filter‐based technique for combined digital estimation of voltage flicker and phasor in power distribution systems

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European Transactions on Electrical power 1993年第2期3卷 131-142页

作者： Kamwa, I. Srinivasan, K. Dr. Innocent Kamwa (1960) has been with the Hydro-Quebec Research Institute (IREQ) since 1988. He is also an. Associate Professor of Electrical Engineering at Laval University Quebec/PQ/Canada. His current interests are broadly in the areas of system identification synchronous machine developments and real-time control and monitoring of electric power systems. He received his B.Eng. and Ph.D. degrees in electrical engineering from the Laval University in 1984 and 1988 respectively. He is a member of the IEEE Power Engineering and Control System Societies and is registered professional engineer in Quebec. (Institut de Recherche d'Hydro-Quebec (IREQ) 1800 Montie Ste-Julie Varennes Canada J3X 1S1 T +514/652-8121 Fax + 514/652-8005) Dr. Krishnaswamy Srinivasan (1943) received his BSc. (Physics University of Delhi/India) in 1962 B.E. (Electrical Engineering) I.I.Sc. in 1965 M.A.Sc. (Power Systems) in 1967 and Ph.D. (Automatic Control) in 1970 from the University of Waterloo/Canada. He is with the Hydro-Quebec utility's Reasearch centre (IREQ) since 1972. His current interests are in micro-computers estimation and control applications in power systems. He is a member of IEEE Power and Automatic Control Societies and is a registered professional engineer in Quebec. (Institut de Recherche d'Hydro-Québec (IREQ) 1800 Montéé Ste-Julie Varennes Canada. J3X 1S1 T +514/652-6250 Fax +514/652-8005)

Electric power quality is of prime importance when sensitive electronic equipment is involved. One of the aspects of power quality is known as flicker level. The present paper proposes an algorithm for real‐time monitoring of voltage flicker based on the Kalman filtering technique. First a stochastic state space model of the system voltage with a linear time‐invariant transition matrix has been established, yet non‐linear in the scalar observation model. Using noisy measurements of a single‐phase voltage, an extended Kalman filter leads to instantaneous value of rms voltage and phase. Then the flicker level has been derived by appropriate filtering and statistical processing on short records of the rms voltage measurements. Simulated and actual data demonstrating the effectiveness of the overall scheme in estimating voltage phasor and flicker for a wide range of swing frequencies are presented and discussed. Among the several power system applications of the new stochastic observer considered, a remote load control concept based on the carrier amplitude modulation is shown being possible and included are test results confirming the filter capability to retrieve sequences of amplitude‐modulated bit patterns travelling through the power line to customer sites. Copyright © 1993 John Wiley & Sons, Ltd.

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An approach to the direct analysis of transient stability

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European Transactions on Electrical power 1993年第3期3卷 241-248页

作者： Djukanovic, M.B. Sobajic, D.J. Pao, Y.‐H. Miodrag B. Djukanovic (1959) received his B.S. M.Sc. and Ph.D. degrees in Electrical Engineering from the University of Belgrade/Yugoslavia in 1982 1985 and 1992 respectively specializing in electric power systems. In 1984 he joined the Electrical Engineering Institute “Nikola Tesla” in Belgrade where he was working on the scientific studies in the field of power systems planning operation and control. In 1985 and 1990 he was appointed as a research scholar at the Royal Institute of Technology Stockholm and Case Western Reserve University Cleveland Ohio. His major in- terests are in the area of power system analysis steady-state and dynamic security and application of neural networks in electric power systems. (Electrical Engineering Institute “Nicola Tesla” ul. Koste Glavinica 8A YU-11000 Belgrad T +3811/2351-619 Fax + 3811/2351-823) Dejan J. Sobajic (1949) received the B.S.E.E. and the M.S.E.E. degrees from the University of Belgrade/Yugoslavia in 1972 and 1976 respectively and the Ph.D. degree from Case Western Reserve University Cleveland Ohio in 1988. At present he is with the Department of Electrical Engineering and Applied Physics Case Western Reserve University Cleveland. He is also the Engineering Manager of A1 WARE Inc. Cleveland. His current research interests include power system operation and control neuralnet systems and adaptive control. He is a member of the IEEE Task Force on Neural-Network Applications in Power Systems and of the IEEE Intelligent Controls Committee. He is the Chairman of the International Neural-Networks Society Special Interest Group on Power Engineering. (Case Western Reserve University Department of Electrial Engineering and Computer Sciences Glennan Building Ohio 44 106 USA T + 1216/421-2380 Fax +1216/368-8776) Yoh-Han Pao (1922) has been a Professor of Electrical Engineering and Computer Science at Case Westem Reserve University (CWRU) Cleveland Ohio since 1967. He has served as chairman of the University's Electrical Engineering Department

The Transient Energy Function (TEF) method has been intensely investigated over the last decade as a reliable and accurate tool for transient stability assessment of multimachine power systems. In this paper we propose the Potential Energy Boundary Surface (PEBS) based method for direct analysis of transient stability. The critical value of transient energy and the Critical Clearing Time (T_CCT) are evaluated without the need for successive calculation and memorization of the system kinetic and potential energy values along the sustained fault trajectory. The method is used for determination of output features in the training phase of the neural‐net based transient security assessment. The proposed approach is tested on the well‐known ten‐generator New England test system demonstrating the validity and accuracy of obtained results. Copyright © 1993 John Wiley & Sons, Ltd.

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Current compensation in three‐phase power systems

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European Transactions on Electrical power 1993年第1期3卷 61-66页

作者： Willems, J.L. Prof. Dr.-Ing. Jacques L. Willems (1939) received a degree in electro-mechanical engineering from the University of Gent. Gent/Belgium the Sc. M. degree in electrical engineering from the Massachusetts Institute of Technology Cambridge and the Ph. D. degree in applied science from the University of Gent in 1963 1964 and 1967 respectively. In 1964 he joined the Engineering Faculty of the University of Gent where he is presently Professor of Electrical Engineering. Since October 1988 he has been Dean of the Engineering Faculty. In 1970 he was on leave at the Division of Engineering and Applied Physics of Harvard University Cambridge Mass./USA. In 1982 he was a Visiting Professor at the Universitk Nationale du Rwanda (Central Africa). His teaching and research interests include power system analysis and control system stability theory. (University of Gent Grote Steenweg Noord 6 8-9052 Gent (Zwijnaarde) Belgium T +3291/645653 Fax +3291/645840)

In this paper the compensation of reactive and unbalanced currents in three‐phase power systems is discussed. The main result proved is that in sinusoidal steady state any current which corresponds to zero total active power can be compensated by means of a reactive element;the compensation of the reactive currents and the compensation of the unbalanced currents in three‐phase power systems are special cases of this result. The explicit expression of the compensating reactances is derived and the multiplicity of the solutions is discussed. The result is illustrated on some examples. Copyright © 1993 John Wiley & Sons, Ltd.

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Short‐term load forecast by plausibility checking of announced demand: An expert‐system approach

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European Transactions on Electrical power 1993年第5期3卷 353-358页

作者： Markovié, M.L. Fraissler, W.F. Milorad L. Marković (1960) received the Dipl.-Ing. and M.Sc. degrees in electrical engineering from the University of Beognd in 1984 and 1990 respectively. From 1985 to 1991 he was at the Institute “Mihajlo Pupin” Beo-grad up to 1987 in the Operation Research group afterwards in the Power System group. In 1990/91 he spent a year at the Austrian Electricity Board (Verbundgesellschaft VG) in Vienna/Austria on a pilot project for expert-system application for operation scheduling. Since September 1991 he is a staff member of the central dispatching department of the VG. His research interests are application of the operations research methods and expert systems in power system control and operation. (Öster-reichische Elektrizitätswirtschafts-AG (Verbundgesellschaft) Hauptlastverteiler Am Hof 6a A-1010 Wien/Austria T +431/531 13 - 23 68 Fax +431/531 13 - 23 16) Walter F. Fraissler (1961) received the Dip1.-Ing. degree in 1984 and the Doctoral degree in 1988 both in Applied Mathematics from the University of Technology of Vienna/Austria. He started his professional experience 1984 as a research assistant at the Department of Economics of the University of Vienna. 1986/87 he attended the Institute for Advanced Studies in Vienna and in 1987 he joined the Austrian Electricity Board (Verbundgesellschaft) in its Electronic Data Processing department. His main interests are applications of econometric and Operations Research methods including expert system technology. (Österreichische Elektrizitätswirtschafts-AG (Verbundgesellschaft) Daten verarbeitung Am Hof 6a A-1010 Wien/Austria T +431/531 13 - 2948 Fax +431/531 13- 4191)

Short‐Term Load Forecast at Verbundgesellschaft (VG ‐ the Austrian Electricity Board) is presented. As the VG has only regional utilities and large industries as purchasers, classical forecast methods are not appropriate. Much more suitable is a plausibility check of a set of announced purchasers demands, for which an expert system has been developed for one to three days ahead forecasts. It has been realized with the help of a rule‐oriented expert system shell based on Prolog, and contains about 250 rules. Normal days as well as special days are considered. The prototype has been tested at the central dispatcher of the VG since autumn 1990. Results and acceptance by the users are promising. Copyright © 1993 John Wiley & Sons, Ltd.

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Interactive power system data preparation and verification using a pc‐editor

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European Transactions on Electrical power 1991年第3期1卷 149-152页

作者： Linke, K. Rumpel, D. Dip1.-Ing. Klaus Linke (1939) VDEis the director of the department "load dispatching and network operation" of Vereinigte Elektrizitatswerke Westfalen AG (VEW). DortmundGermany. After the study of electrical engineering at the Technical University of KarlsruhdGermany he started his professional career in an engineering-concern where he was responsible among others for investigations concerning the installation of process-computers in chemical plants. In 1968 he changed to VEW. Here in 1984 he took over his present position in which he is mainly engaged with the tasks of the management of the HV and EHV network and the power system control together with the problems concerning network automation incident to it. (Vereinigte Elektrizitatswerke Westfalen AG Hauptverwaltung Rheinlanddamm 24 W-4600 Dortmund 1 T +49 23 114 38-42 41) Dr.-Ing. Dieter Rumpel (1932) VDE is full professor and since 1978 head of the Power Systems Institute of Duisburg University Germany. He got his DiplAng. degree from the Technical University Munich and his Dr.-Ing. degree from the Technical University Berlin. Before his call to Duisburg he worked at Siemens AG for 23 years. (Universiiit-GHDuisburg Fachbereich Elektrotechnik PF 10 15 03 W-4100 Duisburg T 4 9 20 313 79-34 37)

For computerized power system operation, all objects of the network must be mapped in a data‐model. For this task, the „Grid Data Language” (GDL) does not apply format‐bound source data, but describes the objects using a format‐free source text. To handle such texts, an editing‐ and verification‐system was implemented. This paper reports its application when describing an extra‐high voltage network for use in a training simulator. In that way, the full content of a dispatcher EHV data‐model could be converted to GDL, requiring a work of 15 to 20 man‐days. Copyright © 1991 John Wiley & Sons, Ltd.

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FUTURE PROPULSION MACHINERY TECHNOLOGY FOR GAS-TURBINE powerED FRIGATES, DESTROYERS, AND CRUISERS

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NAVAL ENGINEERS JOURNAL 1984年第2期96卷 34-46页

作者： BASKERVILLE, JE QUANDT, ER DONOVAN, MR USN The Authors Commander James E. Baskerville USNis presently assigned to Naval Sea Systems Command (NA VSEA) as the Ship Design Manager for the DDG 51 the Navy's next generation surface combatant. A graduate of the U.S. Naval Academy Class of 1969 he is a qualified Surface Warfare Officer and designated Engineering Duty Officer (ED). He received his M.S. degree in Mechanical Engineering and his professional degree of Ocean Engineer from the Massachusetts Institute of Technology (MIT) and holds a patent right on an Electronic Control and Response System. His naval assignments include tours in USSRamsey (FFG-2) Aide and Flag Lieutenant to the Commander Naval Electronic Systems Command and Ship Superintendent Surface Type Desk Officer and Assistant Design Superintendent at NA VSHIPYD Pearl Harbor. He was awarded the Meritorious Service Medal for distinguished performance at Pearl Harbor Naval Shipyard. As an author he has contributed articles to the ASNEJournaland given presentations at local sections on ship design the use of innovative technology in ship repair and maintenance and the costs and risks associated with engineering progress. Commander Baskerville is a registered Professional Engineer in the State of Virginia an adjunct professor teaching marine engineering at Virginia Tech. and in addition to ASNE which he joined in 1975 is a member of SNAME Tau Beta Pi Sigma Xi ASME and the American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE). Dr. Earl R. Quandt:received his degree of Chemical Engineer from the University of Cincinnati in 1956 and his Ph.D. degree in Chemical Engineering from the University of Pittsburgh in 1961. He worked in the naval reactors program at the Bettis Atomic Power Laboratory from 1956 to 1963. Since that time he has been with David Taylor Naval Ship Research and Development Center Annapolis Maryland where he is Head of the Power Systems Division. He contributed to this paper while on a one year assignment to the U.S. Naval Academy as V

A turning point occurred in naval engineering in 1972 when the U.S. N avy chose to use marine gas turbines for the propulsion of its new SPRUANCE and PERRY Class ships. This paper reviews the more than twenty years of experience with turbine technology and its design integration into combat ships needed to make that decision. It is concluded that the availability of a good second generation aircraft derivative engine with proven reliability and a strong commercial base, i.e., the LM-2500, was as important to the decision as was the predicted improved ship effectiveness and cost benefits. This paper discusses improvements that can be made to the twin engine, single gear, single propeller shaft system. Focusing only on this mechanical transmission concept, it addresses the impact of possible improvements to the engine, gear, and shafting. In particular, the paper discusses current LM-2500 related R&D efforts to: (a) obtain improved part-power fuel rates, (b) integrate with a reversing reduction gear, and (c) add on a waste heat recovery steam cycle. Looking ahead to the year 2000, this paper suggests that a successor to the ubiquitous LM-2500 will appear in the 15 MW power range to provide the next step in the evolution of the twin engine package. This new naval engine will most likely be based on an aircraft core that exists at present, such that it will have demonstrated its reliability and commercial potential through many hours of testing prior to its mid-1990 marine conversion. This new engine is expected to offer improved air flow, an excellent fuel rate (approaching a flat 0.30 LB/HP-HR), and effective maintenance monitoring, all at some expense in size, weight, and cost. The year 2000 engine will burn a liquid hydrocarbon fuel similar to JP-5 because of its aircraft origins. Combined with advances in gear and shafting technology, the full twin engine propulsion system of the year 2000 should be markedly lighter, smaller, and more efficient than today's units.

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