改进EWT算法的高压电缆局部放电故障定位方法

Partial discharge fault location method of high voltage cable based on improved EWT algorithm

针对局部放电信号检测时易受到外界噪声干扰,影响定位精度的问题,提出一种基于改进经验小波变换的处理方法。通过建立振荡波电压局部放电仿真模型产生局部放电信号,改进经验小波变换分解信号,获取多分辨率分量,采用Teager能量算子求解MRA分量TEO瞬时能量谱,将峰值点代入行波计算公式确定故障位置。结果表明,与传统EMD和小波变换等方法进行对比,该方法定位更加准确,平均定位误差可达0.37%。

This paper proposes a processing method based on improved empirical wavelet transform to address the problem that the local discharge signal is easily disturbed by external noise and affects the positioning accuracy.The study consists of developing a simulation model of oscillating wave voltage partial discharge to generate the partial discharge signal;improving the empirical wavelet transform todecomposethe signals;obtaining the multi-resolutionanalysis componentto analyze the conponent;solving the instantaneous energy spectrum of MRA component TEO by using Teager energy operator;and setting the peak point into the traveling wave calculation formula to calculate the fault position.The results show that compared with traditional EMD and wavelet transform methods,this method is more accurate,and the average positioning error can reach 0.37%.