基于小波分析的电缆故障行波测距仿真研究

Research on Travelling Wave Fault Locating for Cable Based on Wavelet Analysis

为了实现电缆故障的精确定位,将小波变换模极大值与信号奇异性关系的理论应用于检测电缆故障行波信号。借助电磁暂态仿真软件PSCAD/EMTDC,以35kV交联聚乙烯单芯电缆为原型,建立电力电缆故障仿真测试模型。采用Daubechies小波对故障测试波形进行多尺度、多分辨率分析,仿真结果表明利用小波变换的时频局部化特性能够有效聚焦到电缆故障行波信号中脉冲的起始点,为提高电缆故障定位精度提供了有效的检测方法。

In order to locate cable fault accurately,the theory of modulus maximum of wavelet transformation and the relations of signal singularity is applied in detecting the traveling wave signal of power cable.Simulation test model for power cable is established by the electromagnetic transients simulation tool PSCAD/EMTDC,in which the one core XLPE power cable of 35kV is taken as the prototype.Daubechies wavelet method is used to carry out multi-dimensioned and multi-resolution analysis on fault testing wave.The simulation result shows that the initial point of impulse in cable fault travelling wave can be detected by using of localized time-frequency characteristic of wavelet transformation,which provides an effective test method to improve the locating accuracy of cable fault.