李立江 林海 王佳 陈换过 胡旭晓

摘  要：运行中的输电线路发生故障时，会在故障点产生向两侧传播的电流行波和电压行波。电流行波和电压行波又统称为故障行波，故障行波会在阻抗不连续点发生折射和反射，由此可以通过采集并分析故障行波得到线路故障信息。利用相模变换对三相电流行波进行解耦，通过解耦后得到的独立模量之间的关系可以确定故障类型和故障相，再利用小波变换模极大值的方法标定行波波头，通过波头信息可以得到故障点距离。仿真结果显示，该方法能准确地确定故障类型和故障相，对故障点距离的定位也能达到很高的精度。

关键词：输电线路;行波;故障诊断;小波变换;MATLAB

中图分类号：TP206.3     文献标识码：A

Research on Fault Diagnosis Method of Transmission Line

based on Traveling Wave Theory

LI Lijiang1， LIN Hai2， WANG Jia2， CHEN Huanguo2， HU Xuxiao2

（1.Beijing Sihuida Power Technology Co.， Ltd.， Beijing 101520， China;

2.School of Mechanical Engineering and Automation， Zhejiang Sci-Tech University， Hangzhou 310018， China）

26027960@qq.com; 2049535531@qq.com;Wangjiajia1118@163.com;

chen8025@126.com; huxuxiao@zju.edu.cn

Abstract： When a fault occurs in a running transmission line， a current traveling wave and a voltage traveling wave that propagate to both sides will be generated at the fault point. The current traveling wave and the voltage traveling wave are also collectively referred to as fault traveling waves， which will refract and reflect at the impedance discontinuity point. Therefore， line fault information can be obtained by collecting and analyzing fault traveling waves. The three-phase current traveling wave is decoupled by phase-mode transformation， and fault type and fault phase can be determined through the relationship between the independent moduli obtained after decoupling. Then the traveling wave head is calibrated by the method of wavelet transform modulus maxima， and the fault point distance can be obtained by the wave head information. The simulation results show that the method can accurately determine the fault type and fault phase， and it can also achieve high accuracy in locating the fault point distance.

Keywords： transmission line; traveling wave; fault diagnosis; wavelet transform; MATLAB （Matrix Laboratory）

1   引言（Introduction）

輸电线路是电力系统的重要组成部分，其输送距离长，跨越距离广，沿途气候及环境多变，所以发生故障的概率高，而故障处理的及时性将决定经济损失的大小，故障定位的精确度有助于输电线路故障的抢修。目前使用在输电线路中的故障定位方法主要有阻抗法和行波法两种。阻抗法的原理是根据故障时测得的电压和电流计算出故障回路的阻抗，由于线路长度与阻抗成正比，由此可以求出故障点位置，但阻抗法易受过度电阻、线路分布电容、线路模型和运行方式等多变因素影响，所以测量精度不高[1]。输电线路实际应用更多的是行波法，它是利用故障点产生的暂态行波分析得到故障相关信息，从原理上讲，其测量精度与线路长度、结构、过度电阻无关，能达到高精度故障诊断[2]。……