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Effects of Macroparticle Sizes on Two-phase Mixture Discharge Under DC Voltage

中国电机工程学报 2012年第13期32卷 I0020-I0020,203页

作者： YAO Wenjun HE Zhenghao DENG Heming WANG Guoli ZHANG Man MA Jun LI Jin YE Qizheng HU Hui State Key Laboratory of Advanced Electromagnetic Engineering and Technology （Huazhong University of Science and Technology） Research Institute of China Southern Power Grid Co. Ltd. Guangzhou Branch EHV Power Transmission Company China Southern Power Grid

随着放电等离子体在各个领域应用的不断扩大，两相体放电问题越来越重要，需要解决的基础问题之一即是两相体中放电发生、发展的特点和规律及影响因素。采用21种不同的介质材料研究直流电压下两相体放电的效应，由实验结果可知介质的介... 详细信息

随着放电等离子体在各个领域应用的不断扩大，两相体放电问题越来越重要，需要解决的基础问题之一即是两相体中放电发生、发展的特点和规律及影响因素。采用21种不同的介质材料研究直流电压下两相体放电的效应，由实验结果可知介质的介电常数对放电路径基本无影响，而介质颗粒的粒径大小对两相体放电路径的选择起决定作用，即粒径效应。此外，对颗粒介电常数、电场畸变、光电离作用和颗粒荷电等几个方面进行研究，可知两相体放电的粒径效应与颗粒粒径大小紧密相关。

关键词：两相混合物粒子大小直流电压宏观放电高压输电线路排放法规外部绝缘

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DISCHARGE CHARACTERISTIC TESTS UNDER SALTY AND ACIDITY HAZE SIMULATING CONDITIONS

DISCHARGE CHARACTERISTIC TESTS UNDER SALTY AND ACIDITY HAZE ...

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The ⅪⅩ International Conference on Gas Discharges and Their Applications

作者： CHEN WEIMIN HE ZHENGHAO WANG GUOLI MA JUN ZHANG XIAOFEI XU TAISHENG ZHAO HUAN LIU QINGYING State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology) Research Institute of China Southern Power Grid Co.Ltd.

ISBN: (纸本)9771003651221

The research on electric discharge characteristic in haze is *** may be conducive to improve the high voltage transmission line insulation design and *** paper presents recent research work of discharge characteristic tests under the haze conditions simulated in salty or *** rode-plane gap breakdown and flashover along insulator string surface are involved in the *** show that the discharge voltage is different while the concentration in salty or acidity is *** discharge has its own performance when the condition is in salty and in acidity respectively. Another important phenomenon deduce from the results is that the lowest discharge voltage in simulating haze is no obviously difference between rode-gap and insulator string while the equivalent distance are *** implies that the worst haze may cause discharge directly in space path and not along the surface of the insulator *** may lead to trip the line and the system. Some more research work is expected to do further.

关键词： DISCHARGE CHARACTERISTIC TESTS UNDER SALTY AND ACIDITY HAZE SIMULATING CONDITIONS

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Research on large-area fire monitoring and warning system for power grid

Research on large-area fire monitoring and warning system fo...

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International Conference on Systems and Informatics (ICSAI)

作者： Jiazheng Lu Li Yang Hong Xian Zhang Bo Li Hai Lin Hunan Electric Power Corporation Research Institute The State Grid Corporation of power transmission and transformation equipment anti icing disaster technology key laboratory Changsha China Hunan Bureau of Meteorology Changsha China

The bushfire may seriously effected the neighboring transmission line. Every year a large number of transmission lines tripping accidents happened due to fire. As the transmission line distributed throughout the areas, and the range is wide, and in most areas it's given priority to the hill terrain, seriously affecting the efficiency of the traditional inspection method for transmission line, and is difficult to detect the neighboring fires. Through the establishment of satellite receiving system, it can make use of satellite remote sensing image to accurately monitor the fire situation of transmission line corridor and its surrounding in time Through the development of fire identification method, distance measurement algorithm, 3D fire spread model based on weather information, spatial database and a series of key technology, the large-area fire monitoring and early warning system for transmission line can effective monitor the fire plot real time, release the warning information, and improve the transmission line to fight fires disasters.

关键词： Fires power transmission lines Monitoring Satellites power grids Spatial databases Alarm systems

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Investigation of Heat Dissipation of power Cable Laid in the Tunnel with Ventilation

Investigation of Heat Dissipation of Power Cable Laid in the...

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IEEE PES Asia-Pacific power and Energy Engineering Conference (APPEEC)

作者： Fan Yang Peng Cheng Yongming Yang Jun Chen Tao Chen State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China Chongqing power grid maintenance company Chongqing China Chongqing Electric Power Research Institute Chongqing China

To increase the current carrying capacity of the power cable, more and more power tunnel are installed with ventilation. Hence in the paper the heat dissipation of power cable is investigated. Firstly the model to calculate the thermal field of power cable with natural ventilation is presented based on the fluid mechanics and heat transfer, and the governing equations and boundary conditions are inferred. Then the thermal field for six-loop cables in power tunnel was calculated, which verified the accuracy of the model. In addition, the factors influencing the thermal field with ventilation is investigated, including the size of the power tunnel, the distance between the cable. Finally the current carrying capacity of the power cable is calculated and the economic benefit of the operation mode of power cable is analyzed.

关键词： power cables Mathematical model Fluids Heating Heat transfer Boundary conditions

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Application of total least squares to harmonic state estimation of power system

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International Journal of power and Energy Systems 2012年第3期32卷 93-99页

作者： Zhou, Niancheng Zhu, Jizhong Lin, Li State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing University Shapingba Chongqing 400044 China ALSTOM Grid Inc. 10865 Willows Rd. NE Redmond WA 98052 United States

This paper studies the harmonic state estimation (HSE) considering comprehensively both the harmonic measurement error and network parameter error. The method is based on the total least squares (TLS) and the statistical approach such as probability density function and cumulative probability density function. Both normal distribution and uniform distribution are used to analyse the errors of HSE as well as the corresponding effect of uncertainty errors. Simulation analysis and results based on IEEE 14-bus harmonic testing system are given in this paper.

关键词： Measurement errors

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Time-Varying Waveform Analysis for power Transformer Protection Using Frequency Shift Empirical Mode Decomposition

Time-Varying Waveform Analysis for Power Transformer Protect...

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IET International Conference on Developments in power System Protection

作者： Masoud Bazargan Wuxing Liang Chengxin Li Junyong Liu Jiashi Yang Liangzhong Yao Alstom Research & Technology Centre Provvincial-Level Key Laboratory of Smart Grid Sichuan University Sichuan Electric Power Company State Grid Electric Power Research Institute

ISBN: (纸本)9781622761050

Empirical mode decomposition (EMD) method is a novel time-frequency analysis tool to analyse non-stationary signals, which decomposes the signal concerned into intrinsic mode functions (IMFs) modulated in terms of both amplitude and frequency. The original version of EMD, however, suffers from an algorithm difficulty to separate two individual components, frequencies of which are within an octave. To improve the frequency resolution, a signal pre-processing method is used to shift the frequencies apart based on signal communication theory. This proposed frequency shift EMD has been successfully applied to extract modal parameters of low frequency oscillations for power systems. In this paper, this method is used to analyse the transient signals (inrush current) in the field of power transformer protection. Comparing with low frequency oscillation signals, these signals include more frequency components with faster dynamics. Numerical simulations are conducted to verify the frequency shift EMD. The results show that this method is adequate for time-varying waveform analysis for power transformer protection, and with the information provided by this frequency shift EMD, more robust protection schemes for power transformer could be proposed.

关键词： Waveform analysis power transformer protection Empirical mode decomposition Frequency shift

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Improving power System Damping by Utilizing VSC-HVDC

Improving Power System Damping by Utilizing VSC-HVDC

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IEEE power and Energy Society General Meeting

作者： Si-Ye Ruan Guo-Jie Li T. T. Lie San-Shing Choi State Grid Operation Company Ltd Beijing China Key Laboratory of Control of Power Transmission and Transformation Ministry of Education (Dept. of Electrical Engineering Shanghai Jiao Tong University) Shanghai 200240 China with Dept of EEE School of Engineering Auckland University of Technology Auckland New Zealand School of EEE Nanyang Technological University Singapore

ISBN: (纸本)9781467327275

In this paper, damping power system oscillations with active power and ac voltage modulations of VSC-HVDC is analyzed with the aim of gaining a physical insight into this problem. Enhanced system stability property of the compensated system is shown through detailed analysis. The effects of system parameters and operating conditions on the degree of damping are achievable. It is shown that the feedback signals of frequency deviation are appropriate for both two modulations. The effectiveness is demonstrated through the digital simulation studies using the PSCAD/EMTDC software package, which shows that VSC-HVDC can contribute significantly to damping power system oscillations.

关键词： VSC-HVDC damping ratio active power modulation ac voltage modulation power system oscillation system parameter power system damping absorption of shock Frequency deviation active power Digital simulation Computer Simulation power systems Operating conditions Oscillations realizable feedback signal VOLTS ALTERNATING CURRENT System stability

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A new method of state maintenance decision of relay protection system based on state probability assessment

A new method of state maintenance decision of relay protecti...

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International Conference on Electric Utility Deregulation and Restructuring and power Technologies

作者： Xiong, Xiaofu Hou, Aijun Zhang, Dabo Yang, Qing State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing University Chongqing China Technical Centre of Yunnan Power Grid Company Yunnan China

ISBN: (纸本)9781457703638

The state maintenance of relay protection is very important to the state maintenance of electrical equipments. However, there is no effective available method presently. In this paper, a novel maintenance decision method based on the analysis of the states probability assessment is proposed. In this method, overhaul states are defined according to the consequences analysis of protection system states. Then the transfer pathways and probabilities of other states to the overhaul states can be gotten from state space diagram. Finally, the maintenance arrangements can be decided through the quantitative analysis of the transfer probabilities. The feasibility and effectiveness of this method are also proved by practical examples. © 2011 IEEE.

关键词： Relay protection

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A new tool for lightning performance assessment of overhead transmission lines

A new tool for lightning performance assessment of overhead ...

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

作者： Xie, Yaoheng Dong, Manlin He, Hengxin He, Junjia Cai, Hansheng Chen, Xipeng State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China China Southern Power Grid Electric Power Research Institute Guangzhou China

ISBN: (纸本)9781457714665

A new tool has been developed for the evaluation of the lightning performance of overhead transmission lines. The tool can take into account actual ground flash density distribution along line corridor, cumulative probability function of the lightning current, geometric parameters, insulator string configuration and the topography for each tower of the entire line, etc. Moreover, the tool incorporates several lightning attachment models and a method of ATP-based automated simulation for lightning surge analysis. An application to a typical 500 kV double circuit line of the Chinese transmission system shows that it is convenient for estimating the lightning performance of a total line and studying the effects of different models and criteria on the lightning performance of the line. © 2011 IEEE.

关键词： Electric lines

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A new method of state Maintenance decision of Relay Protection System Based on state Probability Assessment

A new method of State Maintenance decision of Relay Protecti...

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2011 4th International Conference on Electric Utility Deregulation and Restructuring and power Technologies(第四届电力设施管制、重建及能源技术国际会议 DRPT 2011)

作者： Aijun Hou Dabo Zhang Xiaofu Xiong Qing Yang State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing Technical Centre of Yunnan Power Grid Company YunnanChina

The state maintenance of relay protection is very important to the state maintenance of electrical ***,there is no effective available method *** this paper,a novel maintenance decision method based on the analysis of the states probability assessment is *** this method,overhaul states are defined according to the consequences analysis of protection system *** the transfer pathways and probabilities of other states to the overhaul states can be gotten from state space ***,the maintenance arrangements can be decided through the quantitative analysis of the transfer *** feasibility and effectiveness of this method are also proved by practical examples.

关键词： relay protection:state maintenance:probability assessment

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