基于小波变换的配电网单相接地故障仿真研究

Study on wavelet transform based simulation of single-phase grounding fault in power distribution network

小波分析法是一种时频分析方法,能有效地提取线路中的故障信息。首先采用小波分析法进行故障选线,接着对故障线路的小波分析图进行分析。运用一种不含波速的改进型A型测距算法进行故障定位,利用反向行波的模极大值与正向行波极性相反的特点,提取故障行波的反向行波到达时间和正向行波到达时间,在已有的单端测距的算法基础上,进行推导计算,得到最终的测距公式。最后通过Matlab仿真对选线和测距方法进行验证,证明此算法具有可行性。

The wavelet analysis method is a time-frequency analysis method, which can effectively extract the fault information in the line. This method is used to select the line with fault, and then analyze the wavelet analysis chart of the line with fault. An improved A-type location algorithm exclusive of wave velocity is adopted for fault location. The characteristic of the module maximum value of the reverse traveling wave opposite to the polarity of forward traveling wave is utilized to extract the arrival time of the reverse traveling wave and forward traveling wave for the fault traveling wave. On the basis of the available single-terminal range finding algorithm, the derivation calculation is performed to obtain the final range finding formula. The line selection and range finding method were verified with Matlab simulation. The resuhs prove this method is feasible.