小电流接地故障选线装置零序电压启动分析  

Analysis of zero sequence voltage starting of small current grounding fault line selection device

作　　者：田君杨 柳影 薛永端[3] 黄超 TIAN Junyang;LIU Ying;XUE Yongduan;HUANG Chao(Power Dispatching Control Center,Guangxi Power Grid,Nanning 530023,China;Guangxi Vocational University of Agricultural Technical,Department of Information and Electromechanical Engineering,Nanning 530005,China;New Energy School of China Petroleum University(East China),Qingdao 266580,China)

机构地区：[1]广西电网电力调度控制中心,广西南宁530023 [2]广西农业职业技术大学信息与机电工程系,广西南宁530005 [3]中国石油大学(华东)新能源学院,山东青岛266580

出　　处：《供用电》2022年第5期54-60,共7页Distribution & Utilization

基　　金：国家自然科学基金项目(52077221)。

摘　　要：零序电压是配电网发生接地故障的一个重要特征,通常作为小电流接地故障选线装置的启动判据,但现有零序电压启动门槛值的整定普遍偏高,高阻接地时容易拒动。在分析配电网单相接地等值电路的基础上,通过构建经过渡电阻接地时零序电压的计算公式,定量分析了零序电压随系统对地电容及过渡电阻的变化规律,给出了考虑启动灵敏度的零序电压启动门槛值的整定方法及推荐值,利用降低启动门槛值来提高高阻接地时的选线灵敏度。通过对变电站不平衡电压进行监测,验证了所提出的零序电压启动推荐值可躲过最大不平衡电压,不会造成选线装置误动。The zero sequence voltage is an important characteristic of grounding fault in distribution network,it would normally be used as the the starting criterion of small current grounding fault line selection device.But the existing starting threshold is generally rectified to be high,and it is easy to reject the operation when high resistance grounding occurs.Based on the analysis of the equivalent circuit of single phase grounding fault,this paper constructs the zero sequence voltage calculation formula for grounding via a transition resistor.The change regulation of zero sequence voltage with grounding resistance and system capacitive reactance is analyzed quantitatively,the adjustment method and recommended value of zero sequence voltage threshold considering the starting sensitivity are given to improve the line selection sensitivity when high resistance grounding is used by lowering the starting threshold.By monitoring the unbalance voltage of substations,the results prove that the recommendation value of zero sequence voltage start can avoid the biggest unbalance voltage and will not cause line selection device misoperation.

关 键 词：配电网 小电流接地故障 高阻接地 零序电压 选线装置 

分 类 号：TM71[电气工程—电力系统及自动化]