摘要
直流线路纵联差动保护作为行波保护的后备保护之一,为了躲避区外交流系统故障的影响,存在延时长、动作速度慢的问题。为提高直流线路后备保护的动作速度,在分析直流线路区内外故障两端反行波的幅值关系的基础上,提出一种新的纵联保护方法。该方法利用故障发生后一段时间内,线路两端反行波幅值积分的比值来识别区内故障。区内故障时,线路两端反行波幅值积分相差不大;区外故障时,线路两端反行波幅值积分差异明显。基于PSCAD/EMTDC的大量仿真结果表明,该保护方法在各种故障情况下均能可靠、快速地识别区内外故障,对高阻故障也有良好的动作性能,可作为行波保护的快速后备保护。
In order to avoid effect of external AC fault, differential protection of HVDC transmission line, one of backup protections of traveling wave protection, has long time delay and slow operation speed. For improving operation speed of backup protection of HVDC lines, a novel pilot protection method is proposed based on analysis of amplitude relationship between backward traveling waves at both line terminals. Amplitudes of backward traveling waves at both terminals are integrated respectively within short time duration after fault occurs. Internal and external faults are identified with amplitude integral ratio. For internal faults, integral result ratio is relatively small because backward traveling waves at both terminals are approximate to each other. However, for external faults, integral result ratio is relatively large because backward traveling waves at both terminals are quite different. A large amount of simulation results based on PSCAD/EMTDC indicate that the proposed protection method can discriminate internal faults from external faults under various fault conditions, including high resistance fault. The proposed pilot protection can be a rapid backup for traveling wave protection.
作者
李小鹏
汤涌
滕予非
甄威
李旻
LI Xiaopeng TANG Yong TENG Yufei ZHEN Wei LI Min(State Grid Sichuan Electric Power Research Institute, Chengdu 610072, Sichuan Province, China China Electric Power Research Institute, Haidian District, Beijing 100192, China State Grid Sichuan Electric Power Company, Chengdu 610041, Sichuan Province, China)
出处
《电网技术》
EI
CSCD
北大核心
2016年第10期3095-3101,共7页
Power System Technology
关键词
高压直流输电线路
纵联保护
反行波
幅值比较
高阻故障
HVDC transmission line
pilot protection
backward traveling wave
amplitude comparison
high resistance faults
