基于相电流突变量的故障点残流测算方法  

A method for calculating residual current based on phase current fault component

作　　者：宫德锋 乔东伟 张帆[2] 杨雷 徐淼 王书源 薛永端[2] GONG Defeng;QIAO Dongwei;ZHANG Fan;YANG Lei;XU Miao;WANG Shuyuan;XUE Yongduan(Tai’an Power Supply Company of State Grid Shandong Electric Power Company,Tai’an 271000,China;College of New Energy,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]国网山东省电力公司泰安供电公司,山东泰安271000 [2]中国石油大学(华东)新能源学院,山东青岛266580

出　　处：《供用电》2023年第10期81-88,共8页Distribution & Utilization

基　　金：国家电网有限公司科技项目“基于接地故障信息的消弧线圈补偿状态在线评估”(520609220005)。

摘　　要：谐振接地系统中,故障点残流的测算对于故障风险防范、消弧线圈补偿效果评估等运维管理工作具有重要指导意义,然而长期以来始终未找到合理的技术方向。针对谐振接地系统单相接地故障,首先分析了三相电流故障前后的突变量特征,分析表明:故障线路的故障相和健全相的电流突变量之差等于故障点残流,健全相之间的电流突变量之差等于0。然后基于此,构建了3种相间差电流,进而实现故障点残流的测算。为了克服系统不对称的影响,引入故障线路上除出口处之外的任意一个检测点,实现对方法的改进。该方法不需要专用的测量设备,而且MATLAB/Simulink仿真和现场实测证明该方法基本不受系统失谐度和过渡电阻的影响,具有较高的准确性和适用性。In the resonant grounding system,calculation of residual current of grounding point has great guiding significance for prevention of fault risk,compensation effect evaluation of arc suppression coil and other maintenance works.However,a reasonable technical direction has not been found for a long time.Aiming at the single-phase grounding fault of the resonant grounding system,firstly this paper analyzes the fault component characteristic of three-phase current before and after the occurrence of grounding fault.The analysis shows that the difference between faulty phase and healthy phase of faulty line is equal to the residual current and which of two healthy lines is equal to zero.Then based on this,three phase difference currents are constructed which is utilized to calculate the residual current.In order to overcome the influence of system unbalance,the method is improved by introducing any detection point on the fault line except the outlet.The specific measuring equipment is not necessary for the method and MATLAB/Simulink simulation and field test show that the method is basically not affected by detuning degree and transition resistance,and it has higher calculation accuracy and adaptability.

关 键 词：谐振接地系统 单相接地故障 故障点残流 三相电流突变量 系统不对称 

分 类 号：TM73[电气工程—电力系统及自动化]