基于零序电流比较的小电阻接地系统接地故障保护  

Grounding fault protection based on zero sequence current comparison in low resistance grounding system

作　　者：林志超 刘鑫星 王英民 薛永端[2] 孙迪飞 王超 LIN Zhichao;LIU Xinxing;WANG Yingmin;XUE Yongduan;SUN Difei;WANG Chao(Huizhou Electric Power Supply Company,Huizhou 516001,China;College of Information and Control Engineering,China University of Petroleum(East China),Qingdao 266580,China;Kehui Electric Co.,Ltd.,Jinan 250101,China)

机构地区：[1]广东省惠州供电分公司,广东惠州516001 [2]中国石油大学(华东)信息与控制工程学院,山东青岛266580 [3]山东科汇电力自动化股份有限公司,山东济南250101

出　　处：《电力系统保护与控制》2018年第22期15-21,共7页Power System Protection and Control

基　　金：国家自然科学基金项目资助(51477184);广东电网有限责任公司科技项目资助(031300KK52160023)~~

摘　　要：配电网中应用小电阻接地方式可以确保系统能更快排除接地故障,有效降低过电压。但现阶段小电阻接地系统接地故障零序过电流保护定值过高,系统发生高阻接地故障时易拒动。提出一种基于各出线零序电流比较的接地保护方法,利用集中式保护装置收集各出线零序电流信息,选择零序电流幅值远大于其他出线或者相位超前其他线路零序电流以确定相位的线路为故障线路。该方法原理简单,可作为现有接地故障的后备保护,并可有效提高小电阻接地系统接地故障保护灵敏度。The application of low resistance grounding mode in distribution network can ensure that the system can eliminate the grounding fault quickly and reduce overvoltage effectively.The setting value,however,of zero-sequence overcurrent protection in low resistance grounding system is too high to act when high impedance grounding fault occurs.This paper puts forward a grounding protection method based on the comparison of zero-sequence current in each feeder.Zero-sequence current in each feeder is collected by centralized protection device.The feeder whose amplitude of zero-sequence current is far greater than the others or whose phase is in advance of other feeders’for a certain value will be selected as fault feeder.The proposed method with simple principle can be used as backup protection for existing grounding fault protections and can effectively improve the sensitivity of grounding fault protection for low resistance grounding system.

关 键 词：小电阻接地系统 单相接地 高阻接地 接地保护 零序电流比较 

分 类 号：TM862[电气工程—高电压与绝缘技术]