Pole-to-ground Fault Analysis for HVDC Grid Based on Common-and Differential-mode Transformation  

作　　者：Zhen He Jiabing Hu Lei Lin Yuanzhu Chang Zhiyuan He 

机构地区：[1]State Key Laboratory of Advanced Electromagnetic Engineering and Technology,and School of Electrical and Electronic Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [2]Global Energy Interconnection Research Institute,State Grid,Beijing 100192,China

出　　处：《Journal of Modern Power Systems and Clean Energy》2020年第3期521-530,共10页现代电力系统与清洁能源学报（英文）

基　　金：supported in part by National Key Research and Development Program of China (No.2016YFB0900100)。

摘　　要：Pole-to-ground(PTG) fault analysis is of vital importance for high-voltage direct current(HVDC) grid. However, many factors are not considered in the existing studies such as the asymmetrical property of PTG fault, the coupling issue between DC transmission lines and the complexity of the structure of DC grid. This paper presents a PTG fault analysis method, which is based on common-and differential-mode(CDM)transformation. Similar to the symmetrical component method in AC system, the transformation decomposes the HVDC grid into CDM networks, which is balanced and decoupled. Then, a transfer impedance is defined and calculated based on the impedance matrices of the CDM networks. With the transfer impedance, analytical expressions of fault characteristics that vary with space and time are obtained. The proposed PTG fault analysis method is applicable to arbitrary HVDC grid topologies,and provides a new perspective to understand the fault mechanism. Moreover, the analytical expressions offer theoretical guidance for PTG fault protection. The validity of the proposed PTG fault analysis method is verified in comparison with the simulation results in PSCAD/EMTDC.

关 键 词：High-voltage direct current(HVDC)grid pole-to-ground(PTG)fault common-and differential-mode(CDM)transformation DC ciruit breaker(DCCB) 

分 类 号：TM862[电气工程—高电压与绝缘技术] TM721.1