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2008 International Symposium on Electrical Insulating Materials, ISEIM 2008

作者： Du, B.X. Liu, Yong Xia, Y.S. Liu, B.C. Key Laboratory of Power System Simulation and Control of Ministry of Education School of Electrical Engineering and Automation Tianjin University 92 Weijin Road Tianjin 300072 China Tianjin Electric Power Research Institute Tianjin 300022 China

Biodegradable polymers are increasingly expected for substitute of present insulating materials in the electrical and electronic devices. However, their electrical properties are not systematically confirmed and need further investigation. In this paper, biodegradable polyethylene (BDPE) films are employed as the specimens and high density polyethylene (HDPE) films are as the reference. The breakdown endurance of BDPE film is examined using bias DC voltage under UV-irradiation environments. The images of breakdown craters are captured through applying a monocular-video-zoom microscope. Both breakdown area and box dimension of breakdown craters are obtained by an image-pattern- identification technique. The results reveal that for both BDPE and HDPE films, the breakdown voltage, breakdown area and box dimension all decrease with the increase of UV-irradiation level. Based on comparison of the results, it shows that under UV-irradiation environment, breakdown endurance of BDPE film is better than that of HDPE film.

关键词： Biodegradable polymers

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Investigation and analysis of the influence of magnetic wedges on high voltage motors performance

Investigation and analysis of the influence of magnetic wedg...

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2008 IEEE Vehicle power and Propulsion Conference, VPPC 2008

作者： Wang, Shuping Zhao, Zhengming Yuan, Liqiang Wang, Buyao Department of Electrical Engineering State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China Anhui Electric Power Research Institute Corporation Company Ltd. Department of XiangTan Electric Machine Xiangtan China

ISBN: (纸本)9781424418497

To weaken the pulsation of the harmonic magnetic field and improve the wave of the air-gap magnetic field in high voltage motors because of their open slots, magnetic slot wedge should be imbedded into the slot opening. In the paper, through analyzing the air-gap magnetic field distribution of large-scale motors affected by embedding magnetic slot wedges in open slots, the influence of magnetic slot wedge on the motor parameters and performance is discussed in theory. The finite element analysis (FEA) and the experiment results were given, which not only proves the validity of the analysis in the paper, also through the simulation results the proper parameters of magnetic slot wedges for best performance of motors were concluded, which provides a theoretical reference for the manufacturers when choosing or processing magnetic slot wedges. © 2008 IEEE.

关键词： Finite element method

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Investigation and Analysis of the Influence of Magnetic Wedges on High Voltage Motors Performance

Investigation and Analysis of the Influence of Magnetic Wedg...

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Vehicle power and Propulsion Conference

作者： Shuping Wang Zhengming Zhao Liqiang Yuan Buyao Wang Department of Electrical Engineering State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China Anhui Electric Power Research Institute Department of Electrical Engineering State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China Department of Electrical Engineering State Key Laboratory of Control and Simulation of Power System and Generation EquipmentTsinghua University Beijing China Corporation Company Ltd. Of XiangTan Electric Machine XiangTan China

ISBN: (纸本)9781424418480;9781424418497

关键词： Air-gap Magnetic Field Magnetic Slot Wedges Motor Performance

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Breakdown phenomenon identification of biodegradable polyethylene film under UV-irradiation environment

Breakdown phenomenon identification of biodegradable polyeth...

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International Symposium on Electrical Insulating Materials

作者： B. X. Du Yong Liu Y. S. Xia B. C. Liu Key Laboratory of Power System Simulation and Control of Ministry of Education School of Electrical Engineering and Automation Tianjin University TJU Tianjin China Tianjin Electric Power Research Institute Tianjin China

ISBN: (纸本)9784886860057

Biodegradable polymers are increasingly expected for substitute of present insulating materials in the electrical and electronic devices. However, their electrical properties are not systematically confirmed and need further investigation. In this paper, biodegradable polyethylene (BDPE) films are employed as the specimens and high density polyethylene (HDPE) films are as the reference. The breakdown endurance of BDPE film is examined using bias DC voltage under UV-irradiation environments. The images of breakdown craters are captured through applying a monocular-video-zoom microscope. Both breakdown area and box dimension of breakdown craters are obtained by an image-pattern-identification technique. The results reveal that for both BDPE and HDPE films, the breakdown voltage, breakdown area and box dimension all decrease with the increase of UV-irradiation level. Based on comparison of the results, it shows that under UV-irradiation environment, breakdown endurance of BDPE film is better than that of HDPE film.

关键词： Electric breakdown Plastics Films Electrodes Materials Chemicals Polyethylene

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A VSC-HVDC fuzzy controller to damp oscillation of AC/DC power system

A VSC-HVDC fuzzy controller to damp oscillation of AC/DC pow...

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IEEE International Conference on Sustainable Energy Technologies, ICSET

作者： Chunye Li Sheng Li Fuchun Han Jingfu Shang Ermin Qiao College of Electrical and Power Engineering Taiyuan University of Technology Taiyuan China Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control Ministry of Education Beijing China China Electrical Power Research Institute China

The fast control capability of the VSC-HVDC and the process of area mode oscillations are analyzed. An auxiliary fuzzy logic controller designed in Matlab for the voltage source converter based HVDC transmission system, VSC-HVDC, to improve the stability of the AC/DC system is designed to enhance stability by increasing the deceleration energy of oscillation. Simulation results on the IEEE 4-generator AC/DC power systems have shown that the controller can enhance the dynamic stability of interconnected power systems effectively and is robust to the variation of system operating conditions and oscillation modes.

关键词： Fuzzy control Fuzzy systems control systems power systems power system stability Converters power conversion power system simulation power system interconnection power system dynamics

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A power price forecasting method based on nonparametric GARCH model

A power price forecasting method based on nonparametric GARC...

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3rd International Conference on Deregulation and Restructuring and power Technologies, DRPT 2008

作者： Hong, Li Hao, Xiong Weiguo, Li Yi, Sun Guoyi, Xu IEEE North China Electric Power University Wuhan University Beijing Institute North China Electrical Power University Electrical Engineering School North China Electric Power University Beijing China Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control

ISBN: (纸本)9787900714138

Based on nonparametric conditional heteroscedasticity estimation theory, an improved power price forecasting method is proposed in this paper. In this method, according to the practical power price curve, conditional variance function is built and the model is determined by nonparametric estimation method. Besides, in the nonparametric estimation process, the iterative estimation algorithm is introduced to deal with the problem where conditional standard deviation is unpredictable. And the estimation credence of conditional variance function is improved by continually modifying the estimation value of conditional standard deviation as input variance. On the research of day-ahead time series fluctuation characteristics of power price in California in 2000, the time series of Humb node is modeled and forecasted. And the test results show that the model proposed in this paper can better reflect time series volatility clustering characteristics of power price, and it can improve forecasting effect of peak power price by using nonparametric estimation theory. © 2008 DRPT.

关键词： Time series

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Stabilizability of Networked control systems via Packet-loss Dependent Output Feedback controllers

Stabilizability of Networked Control Systems via Packet-loss...

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2008 American control Conference (ACC), vol.9

作者： Junyan Yu Long Wang Mei Yu Yingmin Jia Jie Chen Intelligent Control Laboratory Center for Systems and Control College of Engineering Peking University Beijing China Department of Automation North China Electric Power University Beijing China Key Laboratory of Complex System Intelligent Control and Decision Ministry of Education Beijing Institute of Technology Beijing China

We consider the output feedback stabilizability of networked control systems with bounded packet loss. A packet-loss dependent Lyapunov function is adopted to design packet-loss dependent stabilizing output feedback controllers by resolving some linear matrix inequalities. Moreover, two types of packet-loss processes are discussed: one is the arbitrary packet-loss process, and the other is the Markovian packet-loss process. A numerical example and some simulations are worked out to demonstrate the effectiveness of the proposed design technique.

关键词： Networked control systems Output feedback control systems Switched systems State feedback Lyapunov method Linear matrix inequalities Electrical equipment industry Industrial control Sufficient conditions

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Packet-loss dependent controller design for networked control systems via switched system approach

Packet-loss dependent controller design for networked contro...

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IEEE Conference on Decision and control

作者： Junyan Yu Long Wang Mei Yu Yingmin Jia Jie Chen Intelligent Control Laboratory Center for Systems and Control College of Engineering Peking University Beijing China Department of Automation North China Electric Power University Zhuxinzhuang Beijing China The Seventh Research Division Beihang University Beijing China Beijing Institute of Technology Key Laboratory of Complex System Intelligent Control and Decision Ministry of Education Beijing China

ISBN: (纸本)9781424431236

The stabilization problem of networked control systems with bounded packet loss is addressed. We model such networked control systems as a class of switched systems, and present sufficient conditions for the stabilization by using a packet-loss dependent Lyapunov function. Moreover, different from existing results, we propose the design for packet-loss dependent stabilizing controllers for two types of packet-loss processes: one is a arbitrary packet-loss process, and the other is a Markovian packet-loss process. Several numerical examples and simulations are worked out to demonstrate the effectiveness of the proposed design technique.

关键词： control systems Networked control systems Switched systems Sufficient conditions Optimal control Delay effects Communication system control Communication system traffic control Feedback control Electrical equipment industry

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International Collaboration in Synchronized Measurement Experiment in Russia

International Collaboration in Synchronized Measurement Expe...

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power systems Conference on Advanced Metering, Protection, control, Communication and Distributed Resources

作者： Grobovoy, Andrey Bondareva, Natalia Stepanov, Vladimir Atienza, Edsel Power System Emergency Control Laboratory Ltd Siberian Electric Power Research Institute Russian Federation ABB Automation Schweitzer Engineering Laboratories Inc. United States

ISBN: (纸本)9781424408542

The paper discusses the results of the synchronized measurement experiment recently conducted in the Russian Far East Interconnected power system. An international team of experts conducted a set of unique tests in the bulk power system. The tests used five devices for synchronized phasor measurement. In conjunction with digital fault recorders (DFRs), the phasor measurement units (PMUs) were able to demonstrate the feasibility of using PMUs to monitor and control the Russian Far East Interconnected power system.

关键词： Phasor measurement units

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A Novel Method Of controller Design For Simultaneous Stabilization And Performance Improvement Of An Electromagnetic Levitation system

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Asian Journal of control 2008年第4期9卷

作者： Subrata Banerjee T. K. Sunil Kumar Jayanta Pal Dinkar Prasad Department of Electrical Engineering Indian Institute of Technology Kharagpur India. T.K.Sunil Kumar:was born in 1974 at Calicut India. He received the B.Tech in electrical engineering in 1997 from N.S.S College of Engineering Palakkad (Calicut University) and M.Tech in Power System in 2001 from Regional Institute of Technology Jamshedpur (Ranchi University). Since 2001 he has been pursuing research work for his Ph.D in Electrical Engineering at Indian Institute of Technology Kharagpur. He is a life member of Systems Society of India. His main research interests includes application of control theory and computers to power system model order reduction genetic algorithm PID tuning random search optimization controller deign in 2-DOF configuration and interval systems. Emerson Network Power India.

This paper describes design and implementation of a control philosophy for simultaneous stabilization and performance improvement of an electromagnetic levitation system. An electromagnetic levitation system is an inherently unstable and strongly nonlinear system. To determine the overall closed loop stability for such a system, cascade lead-lag compensation has mostly been reported [1,2]. However, a single lead controller can not satisfy both stability and performance for such unstable systems [3]. Performance enhancement to satisfy the conflicting requirements of fast response with almost zero overshoot and zero steady state error has been successfully achieved by using a two loop controller configuration. The lead controller in the inner loop is designed to ensure stability while the outer loop PI controller is designed for performance enhancement. This approach decouples the twin requirements of stabilization (by the inner loop) and performance achievement (by the outer PI loop). The outermost PI controller has been designed using the ‘Approximate Model Matching’ technique [4]. The proposed control strategy has been implemented and the experimentation has been demonstrated successfully. Different experimental results have been included for verification.

关键词： Electromagnetic levitation lead-lag compensation approximate model matching control switched-mode DC to DC chopper model order reduction technique.

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