基于波前陡度的输电线路单端行波故障测距

Wavefront Steepness Based Single-ended Traveling Wave Fault Location for Transmission Lines

输电线路单端行波故障测距方法中故障点反射波头识别困难。故障初始行波的波前陡度与故障距离相关,文中分析了波前陡度与故障距离的关系,提出了波前陡度与小波波头识别相结合的单端行波定位方法。方法首先对线路故障后记录的单端行波波形求取小波变换模极大值,获取初始波头及各反射波头起始点,再通过首波头波前陡度计算初步故障距离,筛选最接近该距离的小波模极大值以确定故障点反射波头并进行精确测距。算例结果证明了该方法的有效性。

It is difficult to identify the wave head reflected by the fault point in the single-ended traveling wave fault location method for the transmission lines. The wavefront steepness of the initial traveling wave of the fault is related to the distance to the fault.This paper analyzes the relationship between the wavefront steepness and the distance to the fault, and proposes a single-ended traveling wave location method combining the wavefront steepness and wavelet head identification. The method first calculates the wavelet transform modulus maximum value of the waveform of single-ended traveling wave and obtains the starting point of initial wave head and each reflected wave head. The preliminary fault distance is calculated by the wavefront steepness of the first wave head, and the maximum value of the wavelet modulus closest to this distance is selected to determine the reflected wave head of the fault point, so as to obtain the accurate fault location results. The case study results prove the effectiveness of the method.