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作者： Wang, Xuesong Bai, Hua Zhao, Zhengming Yuan, Liqiang China Power Engineering Consulting Group Corporation Beijing 100011 China Kettering University Flint MI 48504 United States State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing 100084 China

With the development of plug-in hybrid electric vehicles (PHEVs), power electronics plays an increasingly important role in electric power train systems. The economic and reliable design of these power electronic systems, e.g., dc/ac inverter and battery charger, will be the inward search to popularize electric vehicles. As an extension of system-level safe operational areas (SSOAs) proposed in our previous literature, this paper details the criteria and mathematical models of SSOA for a battery charger and a three-phase two-level dc/ac inverter. Operational areas were established based on the SSOA. Thermal characteristics of the semiconductor devices, operational modes, and load characteristics were enclosed to enhance the mathematical models. Experiments on a 5-kW charger and a 55-kW/380-VAC inverter validated the effectiveness of SSOA. © 2011 IEEE.

关键词： Metals

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印度大停电与继电保护的三大功能

印度大停电与继电保护的三大功能

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2012年中国智能电网学术研讨会

作者： DONG Xin-zhou 董新洲 CAO Run-bin 曹润彬 WANG Bin 王宾 SHI Shen-xing 施慎行 Dominik Bak State Key Lab of Control and Simulation of Power Systems and Generation Equipments Tsinghua Universi 清华大学电力系统及发电设备安全控制和仿真国家重点实验室北京 100084

简介了印度电网在2012年7月30日和7月31日发生的两起大停电事故。两起事故均起源于同一回输电线路距离保护Ⅲ段因过负荷保护动作跳闸，并导致其他设备继电保护的不合理动作而引发连锁跳闸，造成大面积停电。印度大停电事故暴露了现有电... 详细信息

简介了印度电网在2012年7月30日和7月31日发生的两起大停电事故。两起事故均起源于同一回输电线路距离保护Ⅲ段因过负荷保护动作跳闸，并导致其他设备继电保护的不合理动作而引发连锁跳闸，造成大面积停电。印度大停电事故暴露了现有电力系统的脆弱性，尤其是继电保护在过负荷和系统振荡情况下的动作缺陷。基于对停电事故中继电保护行为的分析，提出了满足现代电网需求的继电保护三大功能：面向系统安全的系统保护功能、预防性保护功能和快速切除故障设备功能。

关键词：停电事故继电保护过负荷故障处理

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Implementation of non-communication protection of double circuit line systems based on integrated protection platform

Implementation of non-communication protection of double cir...

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2011 International Conference on Advanced power System Automation and Protection, APAP 2011

作者： Hu, Xi Dong, Xinzhou Wang, Bin Shi, Shenxing Liu, Kun Li, Youyi State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China Research Ltd. Chaoyang District Beijing 100016 China

ISBN: (纸本)9781424496198

The implementation of non-communication protection of double circuit line systems based on two independent relays has disadvantages like information shareless,complex connection and lack of economic. This paper researched the implementation of non-communication protection of double circuit line systems based on one relay - the integrated protection platform. Hardware structure of the integrated protection platform is described, and software flow of non-communication protection of double circuit line systems which implemented on the integrated protection platform is also described. Large number of RTDS experiments proved that, according to various asymmetrical fault and symmetrical fault, this protection scheme has reliable and sensitive action performance. It is proved that the implement non-communication protection of double circuit line systems based on the intergrated protection platform is feasible. © 2011 IEEE.

关键词： Timing circuits

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A neutral-point potential balancing algorithm for five-level ANPC converters

A neutral-point potential balancing algorithm for five-level...

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International Conference on Electrical Machines and systems (ICEMS)

作者： Kui Wang Yongdong Li Zedong Zheng State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing China

Five-level active neutral-point-clamped (ANPC) converter is a newly emerging topology which can overcome the drawbacks of traditional neutral-point clamped (NPC) converters and flying-capacitor (FC) converters. Its dc-link is subdivided into two equal parts and the main problem is the neutral-point (NP) potential balancing. In this paper, a NP potential balancing algorithm based on zero-sequence voltage injection is presented. By calculating the NP currents of all key zero-sequence voltages, the most appropriate zero-sequence voltage is selected to generate the demanded NP current. Moreover, by further limiting the span of injected zero-sequence voltages, the NP balancing algorithm can make the two IGBTs connected in series operate at fundamental frequency. A three-phase five-level ANPC inverter prototype was built up and experimental results are presented to verify the validity of this algorithm.

关键词： Capacitors Electric potential Switches Voltage control Inverters Insulated gate bipolar transistors Heuristic algorithms

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Numerical simulation on Small Scale Straight-blade and Twisted-blade Vertical Axis Wind T

Numerical Simulation on Small Scale Straight-blade and Twist...

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2011 SSITE International Conference on Future Material Research and Industry Application(FMRIA 2011)

作者： Lv Yongzhe Jiang Dongxiang Jiang Yong State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Thermal Engineering Tsinghua University

This paper presents an analysis on the performance of vertical axis wind turbine of two types, namely straight-blade vertical axis wind turbine(SB-VAWT) and twisted-blade vertical axis wind turbine(TB-VAWT)An attempt of this simulation is to identify which type performs better in the same wind conditions and swept areaThree-dimensional computational fluid dynamics(CFD) was adopted in this analysis, after solid models of them were generatedPreliminary results of torque, power and aerodynamics in the fluid field were obtained for discussionFinally, there provided some guidance for future wind tunnel tests.

关键词： straight-blade vertical axis wind turbine twisted-blade vertical axis wind turbine numerical simulation performance aerodynamics

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Numerical simulation on Small Scale Straight-blade and Twisted-blade Vertical Axis Wind Turbine

Numerical Simulation on Small Scale Straight-blade and Twist...

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2011 International Conference on Energy and Environment(ICEE 2011)

作者： Lv Yongzhe Jiang Dongxiang Jiang Yong State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Thermal Engineering Tsinghua University

This paper presents an analysis on the performance of vertical axis wind turbine of two types, namely straightblade vertical axis wind turbine(SB-VAWT) and twisted-blade vertical axis wind turbine(TB-VAWT). An attempt of this simulation is to identify which type performs better in the same wind conditions and swept area. Three-dimensional computational fluid dynamics(CFD) was adopted in this analysis, after solid models of them were generated. Preliminary results of torque, power and aerodynamics in the fluid field were obtained for discussion. Finally, there provided some guidance for future wind tunnel tests.

关键词： straight-blade vertical axis wind turbine twistedblade vertical axis wind turbine numerical simulation performance aerodynamics

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Study on the loss reduction of high-efficient high-voltage series induction motors

Study on the loss reduction of high-efficient high-voltage s...

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2011 International Conference on Electrical Machines and systems, ICEMS 2011

作者： Lingyun, Bai Zhengming, Zhao Yi, Lei Shuping, Wang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing 100084 China Beijing Command College of CAPF Beijing 100012 China Anhui Electrical Research Institute Hefei 230022 China

ISBN: (纸本)9781457710445

On the basis of analyzing the composition of losses in high-efficient high-voltage asynchronous motors, the approaches of increasing the efficiency of the motors is investigated in this paper. The approaches concern with the improvement of material, winding, fan, magnetic groove and so on. By taking the economy and efficiency into account synthetically, the design of the YKK series induction motors is carried on, and it is realized by software simulation. © 2011 IEEE.

关键词： Induction motors

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Effects of nonlinear gradient index on radiative heat transfer in a one-dimensional medium by the DRESOR method

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Journal of Physics: Conference Series 2012年第1期369卷

作者： Z C Wang Q Cheng G H Wang Z F Huang H C Zhou State Key Laboratory of Coal Combustion Huazhong University of Science and Technology Wuhan 430074 Hubei People's Republic of China State Key Laboratory of Control & Simulation of Power System & Generation Equipment Department of Thermal Engineering Tsinghua University Beijing 10084 P. R. China To whom any correspondence should be addressed

The DRESOR (Distribution of Ratios of Energy Scattered by the medium Or Reflected by the boundary surface) method is applied for radiative heat transfer in a one-dimensional medium with a nonlinear gradient index and gray boundary surfaces. In this proposed method, the DRESOR values calculated by the Monte Carlo method express quantitatively the impact of scattering on radiative transfer and the radiative intensity with high directional resolution of high precision can be easily obtained. With given media characteristics and boundary conditions, the temperature and radiative flux distributions inside the medium are calculated under the condition of radiative equilibrium. It is shown, in the cases studied, that the DRESOR method has a good accuracy. The temperature distributions have a node with different kinds of sine changed gradient index distributions under the same boundary emissivity. The impact of the gradient index on the radiative heat transfer is considerable, and the same as that of the ratios of its amplitude and average index. Besides, the effects of optical thickness, boundary emissivity and scattering phase function on radiative transfer also should be paid adequate attention.

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Research on pilot protection applied in aircraft annular power distribution system

Research on pilot protection applied in aircraft annular pow...

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2011 International Conference on Advanced power System Automation and Protection, APAP 2011

作者： Jiang, Zhongshan Liu, Yanping Wang, Bin Dong, Xinzhou Wang, Yan Naval Aeronautical and Astronautical University Yantai 264001 China State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian Beijing 100084 China Beijing Wuzi University Beijing 101149 China

ISBN: (纸本)9781424496198

In the annular power distribution system, short-circuit fault of bus-bars will do fatal harm to aircraft, and it is necessary to protect the ring-net bus-bars. Protecting bus-bars has to meet the requirements that protection devices do not refuse to operate and backup protection devices do not act incorrectly. This paper builds a model about the annular power distribution system and stimulates the fault system based on MATLAB. According to the fault features, directional blocking pilot protection is put forward. The results prove that the new method can achieve automatic isolation of the bus-bar at fault, ensures the safety of aircraft power distribution system, and it is of great importance to improve the reliability of aircraft power distributing. © 2011 IEEE.

关键词： MATLAB

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Research on characteristics of surface electric field on transmission lines under lightning stroke

Research on characteristics of surface electric field on tra...

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2011 7th Asia-Pacific International Conference on Lightning, APL2011

作者： Li, Qian Yu, Zhanqing Zeng, Rong Zhang, Yong Li, Zhizhao Zhuang, Chijie Liao, Yongli State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China Department of Mathematical Sciences Tsinghua University Haidian District Beijing 100084 China Electric Power Research Institute CSG Guangzhou China

ISBN: (纸本)9781457714665

Lightning is a major cause of power interruptions in power transmission lines. Nowadays the Leader Progression Model is an advanced method to evaluate the shielding failure probability of transmission lines. Calculating the surface electric field on phase conductors and ground wires precisely is important, because the surface electric field has great effect on the upward leader inception. In this paper, the influence of lightning current and some other factors on surface electric field were analyzed. © 2011 IEEE.

关键词： Electric lines

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