输电线路单端行波故障测距的研究

分析了影响单端行波测距法精度的主要因素,包括母线端接线、接地电阻、T型线路结构、故障位置等,指出行波的极性和幅值是行波最重要的两个特征,提出了考虑电流行波极性和电压行波极性的综合行波极性判别法,该方法较容易识别线路内的折反射行波和线路外的其它线路折反射行波,与仅利用电流或电压行波的方法相比,判别的可靠性有很大提高.同时指出对单端行波测距而言,一些线路结构和故障情况下无法进行单端行波测距,单端行波测距法还存在测距死区问题.用单端法进行测距需要结合阻抗法进行联合单端测距,在单端行波法失效的情况下以阻抗法的测距结果作为补充,才能弥补单端行波法和单端阻抗法的不足,实现精确故障定位.

STUDY ON SINGLE TERMINAL TRAVELLING WAVE FAULT LOCATION OF TRANSMISSION LINE

The main factors influencing single-terminal travelling wave fault location precision, including the generatrix structure, grounding resistance, T type line structure and fault position, are analyzed. The author points out that the most important features of travelling wave are its polarity and amplitude, and proposes a comprehensive method to judge travelling wave polarity in which current travelling wave polarity and voltage travelling wave polarity are considered. It is easy for this method to identify whether the travelling wave is reflect or refract travelling wave from the line itself or that from other lines, and comparing with other methods the reliability of the judgment can be greatly improved. It is also pointed out that the single terminal travelling wave fault location method is not suitable under certain line structure and fault conditions, besides there is dead zone in single terminal travelling wave fault location method. To implement reliable fault location by single terminal fault location method, it is necessary to conduct combined single terminal fault location in company with impedance method; when single terminal travelling wave fault location method is failed, the fault location result from impedance method must be used as the supplement of the former to make up the insufficient of both above-mentioned fault location methods and realize the accurate fault location.