交直流交叉跨越碰线故障及其保护风险分析  

Touching Fault and Its Risk Protection Analysis for AC/DC Crossed Transmission Lines

作　　者：李晓华[1] 梁子鹏 冯家伟[1] 张少凡 曹杰 丁晓兵[3] LI Xiaohua;LIANG Zipeng;FENG Jiawei;ZHANG Shaofan;CAO Jie;DING Xiaobing(School of Electric Power,South China University of Technology,Guangzhou 510640,China;Guangzhou Power Supply Co.,Ltd.,Guangzhou 510620,China;Power Dispatching and Control Center of China Southern Power Grid,Guangzhou 510623,China)

机构地区：[1]华南理工大学电力学院,广东省广州市510640 [2]广州供电局有限公司,广东省广州市510620 [3]中国南方电网电力调度控制中心,广东省广州市510623

出　　处：《电力系统自动化》2020年第9期52-59,共8页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51777079);国家自然科学基金委员会-国家电网公司智能电网联合基金资助项目(U1766213)。

摘　　要：中国直流输电工程输送距离长、跨度大,与交流线路跨越的情况日益增多。电网出现了新的故障形式--交直流碰线故障,其故障特征及对继电保护的影响研究比较匮乏。对碰线故障的特征进行理论分析,基于详细直流工程PSCAD/EMTDC仿真平台搭建交直流同塔模型,对碰线故障引起的特征量及其影响因素进行研究,并分析其对交直流保护动作特性的潜在挑战。仿真结果表明:碰线故障引入的工频分量会使直流线路行波保护动作率降低;行波保护与交直流碰线保护在保护配合范围内存在动作死区;交流距离保护灵敏度下降。The DC transmission projects in China have long transmission distance and large span, and the crossing between AC lines and DC lines is increasing day by day. A new fault type, touching fault of AC/DC transmission lines, emerges. There is lack of study on characteristics of touching fault and their influence on relay protection. Theoretical analysis on characteristics of touching fault for AC/DC transmission lines is made. AC/DC tower model is developed based on PSCAD/EMTDC simulation platform of detailed DC project. The characteristic quantities and key factors caused by touching fault are investigated, and its potential challenges on operation characteristic of AC/DC protection are analyzed. Simulation results show that the fundamental frequency component introduced by touching fault can reduce the action rate of traveling wave protection for DC lines, there is an action dead zone in protection range between traveling wave protection and touching protection for AC/DC lines, and the sensitivity of AC distance protection is lower.

关 键 词：交直流交叉跨越 碰线故障 行波保护 交流保护 动作死区 灵敏度 

分 类 号：TM75[电气工程—电力系统及自动化]