基于联合电压判据的高压并联电容器单相接地故障保护方法  

Single-phase earth fault protection method based on combined voltage criterion in high voltage shunt capacitor

作　　者：马伟东 孔圣立 刘超 宋闯 刘尧 MA Weidong;KONG Shengli;LIU Chao;SONG Chuang;LIU Yao(State Grid Henan Electric Power Research Institute,Zhengzhou 450052,China)

机构地区：[1]国网河南省电力公司电力科学研究院

出　　处：《电力系统保护与控制》2019年第22期142-147,共6页Power System Protection and Control

基　　金：国家电网有限公司科技项目资助(52170218000M)~~

摘　　要：针对目前电容器组单相接地故障保护存在的不足,提出了一种通过比较三相对地电压来进行单相接地故障判别的联合电压判据保护方法。对构造联合电压判据的电压幅值比较法和电压相位比较法进行了理论分析,给出了保护定值的计算方法。通过分析比较两种方法的优劣,推荐采用电压幅值比较法来构造联合电压判据,并通过仿真计算,验证了联合电压判据的可行性。由于只有在三相电压均满足条件时,保护才能动作,故联合电压判据具备较好的防止PT断线造成保护误动的能力。In allusion to the insufficiency of capacitor bank single-phase fault protection at present,this paper puts forward a combined voltage criterion protection method by comparing three-phase ground voltage to distinguish the single-phase earth fault.Aiming at constructing combined voltage criterion,voltage value comparison method and voltage phase comparison method are analyzed theoretically and a protection setting calculation method is given.Through analyzing and comparing the advantage and disadvantage of the two methods,voltage value comparison method is recommended to construct the combined voltage criterion.Furthermore,the feasibility of combined voltage criterion is verified by simulation.Since the protection will act only if all the three phase voltages are satisfied,the combined voltage criterion has a better function to prevent protection misoperation caused by PT breaking.

关 键 词：联合电压 电压幅值 电压相位 比较 并联电容器 单相接地 

分 类 号：TM7[电气工程—电力系统及自动化]