基于最小二乘法的变压器接地故障励磁涌流仿真分析  

Simulation analysis of inrush current in transformer grounding fault based on least square method

作　　者：张文军 张文斌[2,3] 易善军[1] 徐柳飞 杨丹琳 Zhang Wenjun;Zhang Wenbin;Yi Shanjun;Xu Liufei;Yang Danlin(State Grid East Inner Mongolia Electric Power Supply Co.,Ltd.,Hohhot 010020,China;NARI Group Corporation,Nanjing 211106,China;NARI Technology Co.,Ltd.,Nanjing 211106,China)

机构地区：[1]国网内蒙古东部电力有限公司,呼和浩特010020 [2]国网南京南瑞集团公司(国网电力科学研究院),南京211106 [3]国电南瑞科技股份有限公司,南京211106

出　　处：《电子测量技术》2020年第5期47-50,共4页Electronic Measurement Technology

摘　　要：在分析涌流和故障电流的波形特点的基础上,采用最小二乘矩阵方法来实现对电流分量进行精确提取,建立得到电流能量信息熵的计算模型,以此实现对励磁涌流和短路电流的准确分类。对判据性能进行分析的过程中采用PSCAD构建仿真模型,并且在仿真过程中专门设置了短路故障与空载合闸的情况。仿真结果得到:通过最小二乘法算法进行分解计算可得到保护启动之后,到变压器出现励磁涌流时,以差流方法可以计算出更高H值,形成多种分量,非周期分量都呈现衰减特点,符合闭锁的判据条件。对变压器实施内部故障仿真发现其内部短路后,将会形成很高的稳态差流正弦度。利用变压器故障可以显著降低工频周波数据信息熵,最低可以达到0。发生变压器合闸故障的情况下,差动电流包括励磁涌流与故障电流两个分量。Based on the analysis of the waveform characteristics of inrush current and fault current,the least square matrix method is adopted to extract the current components accurately and establish the calculation model of current energy information entropy,so as to realize the accurate classification of inrush current and short circuit current.PSCAD was used to build the simulation model in the process of analyzing the performance of the criterion,and the short-circuit fault and no-load closing were specially set in the simulation process.Simulation results show that after the protection is started by decomposition calculation with the least square method,higher H value can be calculated with the differential current method when the transformer is magnetizing inrush current,forming a variety of components and non-periodic components have attenuation characteristics,which meet the criteria of locking.A high sinusoidal steady-state differential current will be formed after the transformer is short-circuited by internal fault simulation.Using transformer fault,the entropy of power frequency cycle data can be reduced to 0.In the case of transformer closing fault,the differential current includes two components:magnetizing inrush current and fault current.

关 键 词：变压器 差动保护 励磁涌流 最小二乘法 仿真分析 

分 类 号：TM772[电气工程—电力系统及自动化]