输电线路故障测距.doc

输电线路故障测距的研究 摘 要：对高压架空输电线路进行准确的故障测距是保障电力系统安全稳定运行的有效途径之一。为此，文章全面地介绍了国内外在此方面的研究现状。根据各种测距算法采用的原理不同，将现有的各种测距算法分为阻抗法、故障分析法、和行波法。阻抗法是根据故障时测量到的电压、电流量而计算出故障回路的阻抗，由于线路长度与阻抗成正比，因此便可求出由装置装设处到故障点的距离；故障分析法是利用故障时记录下来的电压、电流量，通过分析计算，求出故障点的距离；行波法是根据行波传输理论实现输电线路的故障测距方法，按其原理可分为A、B、C型3种方法，然后利用小波变换对输电线路故障测距进行模拟仿真。最后，对高压架空输电线路故障测距的研究及应用前景进行了展望。 关键词：故障测距；行波；输电线路；小波变换 Abstract：Because the accurate fault location for high voltage transmission line plays increasingly important role in power system, the general situation of the research in this field in China and in other countries is reviewed in this paper. All the existing algorithms can be classfied into four main methods: impedance location, fault analysis location and travelling wave location. Impedance location is that the impedance of the fault loop is worked out from the voltage and circuit measured. Because the length of the line is proportional to the impedance, so the distance from the equipment of location to the fault position can be worked out. Fault analysis location is that the impedance of the fault is worked out by analysis of the voltage and circuit obtained when the fault occurred. Travelling wave location is to locate the fault point based on the theory of the travelling wave. Travelling wave location can be classfied into three methods based on the principle of the method: A, B and C methods. Then use wavelet transform fault location on transmission line on simulation. At last, the prospects in fault location are described. Key works：fault location algorithm travelling wave；transmission line； wavelet transform 1. 概述 高压输电线路是电力系统的命脉，它担负着传送电能的重任。同时，它又是系统中发生故障最多的地方，并且极难查找。因此，在线路故障后迅速准确地把故障点找到，不仅对及时修复线路和保证可靠供电，而且对电力系统的安全稳定和经济运行都有十分重要的意义。 根据故障测距装置的作用，对它提出以下几点基本要求[1]。 1) 可靠性 2) 准确性 3) 经济性 4) 方便性 目前已有的输电线故障测距装置按其工作原理可以分为以下几种。 1) 阻抗法 2) 故障分析法 3) 行波法 本论文的主要工作如下： 1）2）3） 图2-1 单相线路内部故障 设m端为测量端，则测量阻抗可表示为 (2-1) 3 故障分析法 由图2-1可写出下列电压方程 (3-1) 由于故障点与m端电流的故障分量之间存在以下关系 (3-