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Asia-Pacific Symposium on Electromagnetic Compatibility (APEMC)

作者： Min Li Rong Zeng Dawei Yang Zhanqing Yu Ruihai Li Lei Liu Bo Zhang Huaying Zhang State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China Technology Research Center China Southern Power Grid Company Limited China

ISBN: (纸本)9781424456215

The corona performance and the electromagnetic environment of the transmission system has become a crucial issue that has been taken into consideration in the line design, and among which audible noise (AN) is one of the most important factors. The wind in the high altitude area is mostly strong, and could greatly influence the AN. This paper, based on the high altitude HDVC test line, studied the characteristics of AN generated by the transmission line, and analyzed the influence of wind velocity and wind direction on the AN lateral profile.

关键词： Acoustic noise HVDC transmission Testing Wind speed Corona power transmission lines Microphone arrays Voltage Electromagnetic compatibility power engineering and energy

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Tests on electromagnetic environment of ultra HVDC transmission lines in high altitude region

Tests on electromagnetic environment of ultra HVDC transmiss...

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Asia-Pacific Symposium on Electromagnetic Compatibility (APEMC)

作者： Zhanqing Yu Rong Zeng Min Li Ruihai Li Lei Liu Bo Zhang Zheng Zhang Huaying Zhang State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China Technology Research Center China Southern Power Grid Company Limited China

ISBN: (纸本)9781424456215

The Ultra High Voltage DC power transmission technique is developed quickly in China but used barely in the world. Corona phenomenon in high altitude region is more serious, and corresponding electromagnetic environment is more severe as well. A UHVDC test lines are completed for tests in Kunming, China, with an altitude of 2100 m. An automotive electromagnetic environment testing system was installed under the line. Measurement of electromagnetic environment was carried out. Radio interference, audible noise, resultant electric field and ion current density at ground level were measured at different voltage from ±800kV to ±1000kV, and atmosphere conditions including sunny, rainy and cloudy weather. The measured result show some difference with those acquired at sea level and is significant for further studies of corona mechanism under high altitude condition. Measured results were compared with the calculated results.

关键词： HVDC transmission Atmospheric measurements Sea measurements Electromagnetic measurements Voltage Corona power transmission Automotive engineering System testing Electromagnetic interference

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Radio interference of Ultra HVDC transmission lines in high altitude region

Radio interference of Ultra HVDC transmission lines in high ...

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Asia-Pacific Symposium on Electromagnetic Compatibility (APEMC)

作者： Zhanqing Yu Rong Zeng Min Li Ruihai Li Lei Liu Dawei Yang Zheng Zhang Bo Zhang Feng Tian State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China Technology Research Center China Southern Power Grid Company Limited China

ISBN: (纸本)9781424456215

Corona phenomenon of Ultra High Voltage DC in high altitude region is more serious, and corresponding electromagnetic environment is more severe as well. Radio Interference is the most important consideration during the design and operation. Characteristics of RI and its influence factors were studied based on an UHVDC test line with an altitude of 2100 m in the National Engineering laboratory for UHV Technology, located in Kunming, China. The measuring system of RI long term tests was introduced. Lateral and longitudinal distribution and spectrum of RI near the transmission line were analysed at various voltages, weather conditions.

关键词： Electromagnetic interference HVDC transmission Voltage Corona Testing power transmission lines DC generators Conductors Transmission line measurements Electromagnetic compatibility

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Analysis of cutting-edge techniques in the high voltage and high power adjustable speed drive systems

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Science China(Technological Sciences) 2009年第2期52卷 442-449页

作者： ZHAO ZhengMing BAI Hua YUAN LiQiang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

The high voltage and high power adjustable speed drive (ASD) system is one of the most attractive fields in power electronics, and it is also a very crucial technique for energy saving and emission reduction. This paper discussed and analyzed the main cutting-edge knowledge and issues in the process of exploiting the high voltage and high power ASD system.

关键词： high voltage and high power inverter safe operation area pulse and pulse sequence

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Nanosecond-pulse Dielectric Barrier Discharge Using Magnetic Compression Solid-State Pulsed power

Nanosecond-pulse Dielectric Barrier Discharge Using Magnetic...

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IEEE International power Modulator and Hogh Voltage Conference

作者： Tao Shao Yang Yu Cheng Zhang Zheng Niu Dongdong Zhang Jue Wang Yaohong Sun Ping Yan Yuanxiang Zhou Institute of Electrical Engineering Chinese Academy of Sciences State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Electrical Engineering Department Tsinghua University

ISBN: (纸本)9781424471317

Dielectric barrier discharge excitated by unipolar pulsed power is a promising approach for producing non-thermal plasma at atmospheric pressure. A magnetic compression solid-state pulse power generator is used to produce dielectric barrier discharge (DBD). The generator is capable of providing repetitive pulses with the voltage of up to 30 kV and duration of 70 ns at a 300 Ω resistive load. This paper illustrates electrical characteristic and luminous emissions of DBD excitated by repetitive unipolar nanosecond-pulses in atmospheric air. Different from common DBD excitated by high-voltage AC sources, discharge current of DBD in the experimental investigation can be on an order of tens of amperes. When the DBD is created using two liquid electrodes, the luminous emissions from the obverse and flank sides of liquid electrodes show that no filament is observed and the discharge is homogeneous and diffuse in the whole discharge regime.

关键词： Dielectric barrier discharge Pulsed power Magnetic compression Repetitive nanosecond pulses Atmospheric pressure air Gas discharge Homogeneous discharge

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IGBT modeling for analysis of complicated multi-IGBT circuits

IGBT modeling for analysis of complicated multi-IGBT circuit...

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2009 2nd Conference on power Electronics and Intelligent Transportation System, PEITS 2009

作者： Deng, Yi Zhao, Zhengming Yuan, Liqiang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781424442461

A new IGBT (Insulated Gate Bipolar Transistor) model for simulation of eomplicated multi-IGBT cireuits is presented. Based on the gate chargc and discharge behaviors of IGBT, it piecewise models the turn-on and -off transient oflGBT, and simulates the static characteristics with curve fitting method . With the kcy features of high simulation spccd, easy parameters extraction and clear physical meaning, the model is available for various IGBTs and system level circuits. This paper describes the structure and equivalent circuit of the model in detail, implements it with the simulation tool of PSIM package, and determines the parameters of the model for an IGBT of FF300R12ME3 as an example. The accuracy of the model is verified by the comparison between the simulated and experimental results. ©2009 IEEE.

关键词： Equivalent circuits

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Corrigendum to “Using fuzzy theory and information entropy for water quality assessment in three Gorges region, China” [Expert systems with Applications 37 (3) (2010) 2517–2521]

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Expert systems with Applications 2010年第6期37卷 4720-4720页

作者： Li Liu Jianzhong Zhou Xueli An Yongchuan Zhang Li Yang Dispatch & Communication Center Hunan Electric Power Company Hunan Province Changsha 410007 China College of Hydroelectric and Digitalization Engineering Huazhong University of Science and Technology Hubei Province 430074 Wuhan China State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Thermal Engineering Tsinghua University Beijing 100084 China

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Shaft crack analysis and diagnosis for the 600mw steam turbine generator

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key Engineering Materials 2009年 413-414卷 591-598页

作者： Dongxiang, Jiang Liangyou, Hong Qian, Huang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Thermal Engineering Tsinghua University Beijing 100084 China

Abstract: In order to find the cause of the shaft crack appeared in a 600MW steam turbine generator, several measurements are taken. The shaft assembly consists of three parts: shrink-fitted coupling, shaft and key which are used to transfer torque between coupling and shaft. First, the natural frequency of the shaft system is calculated. The result shows that the vibration signal contains the frequency nears the second natural frequency of the steam turbine shaft system. Second, stress field near the damaged coupling and shaft is analyzed using finite element method. The torque under different operation condition is calculated before stress analysis and applied to the shaft assembly, then. And, local stress concentrations position calculated is proved to be coincident with the place crack initiation. Finally, the cause of the fault is analyzed: at least three causes have found to be having something to do with the crack fault.

关键词： Finite element method

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Selection method of transformer interconnecting distributed generation and distribution networks

Selection method of transformer interconnecting distributed ...

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IEEE/PES Transmission and Distribution Conference and Exhibition: Asia and Pacific

作者： Shouzhen Zhu Lin Geng Jinghong Zheng Xiaoyu Wang DaeHee Choi Yang Li State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing China

Recently, DG (distributed generation) is rapidly developed around the world. But there are several problems in the grid-connected operation. The paper focuses on the selection of proper transformers to meet the grounding requirements in the distribution networks. Through theory analysis and simulation, optimal selection methods are proposed. Yg/¿-connection transformer is suitable for small resistance grounding distribution networks while ¿ /Yg and ¿ / ¿ connection transformers are fit for small current neutral grounding networks. The conclusions are useful for the DG-connected power system.

关键词： Distributed control Grounding power transformer insulation power system simulation Coils power system interconnection Distributed power generation Ferroresonance Voltage power generation

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Research on fault mechanism of icing of wind turbine blades

Research on fault mechanism of icing of wind turbine blades

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World Non-Grid-Connected Wind power and Energy Conference, WNWEC

作者： Minghao Zhao Dongxiang Jiang Shaohua Li State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Thermal Engineering Tsinghua University Beijing China

In this paper, fault mechanism of icing of wind turbine blades is studied theoretically and experimentally. First, the aerodynamic performance of a wind turbine's primary airfoil under normal and icing conditions are simulated using Fluent software separately to analyze the geometry effect of icing on wind turbine. Then the formation and characteristics of vibration signal on main shaft caused by mass unbalance of wind turbine's rotor are analyzed using rotor dynamics theory to evaluate mass effect of icing on wind turbine. Finally, corresponding experiments are carried out on a self-made small wind turbine under laboratory conditions to testify the former theoretical analysis.

关键词： Wind turbines Blades Aerodynamics Automotive components Solid modeling Analytical models Software performance Performance analysis Geometry Shafts

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