基于信号相位检测的输电线路行波故障测距方法

通过对输电线路短路故障暂态过程中电流行波的相位变化情况进行分析，发现短路故障发生时，电流行波中出现的暂态分量将导致电流行波的相位发生突变。根据这一特征，文章提出将信号相位检测用于故障测距的新方法，该方法与传统测距方法的区别在于确定信号突变点的方式不同。新方法利用小波变换提取信号相位，并通过相位模极大值的计算确定信号突变点。仿真实例证明新方法是可行的，对于幅值变化轻微的信号，采用文章提出的相位检测法对突变点的检测效果更好。由于该方法计算复杂，因此适合作为高阻接地等特殊故障条件下对现有测距方法的补充。

Transmission Line Traveling Wave Fault Location Based on Signal Phase Detection

By means of analyzing the phase variation of current traveling wave during the transient process of short circuit fault occurred in transmission line, it is discovered that the phase of current traveling wave will chop due to the appearance of transient component in the current traveling wave while short circuit fault happens. According to this feature, the authors propose a new method to apply signal phase detection in fault location. The difference between the proposed method and traditional fault location lies in the difference of the ways to determine the chop point of signal. In the proposed method, the phase of signal is extracted by wavelet transform and by means of calculating the modulus maximum of the signal the chop point of signal is determined. Case simulation results show that the proposed method is feasible. With regard to the signal with slightly varying amplitude, the proposed phase detection method is better for the detection of chop point. Due to the complexity of its calculation, the proposed method is suitable for the supplement of existing fault location methods under special fault conditions such as high resistance grounding and so on.