基于小波变换和WVD分布的电子式互感器突变性故障协同诊断方法

A collaborative diagnosis of abrupt-changing fault of electronic instrument transformer based on wavelet transform and WVD

针对现有互感器故障诊断方法中突变性故障和系统异常干扰信号同时发生时缺乏应对方案的问题,提出了一种基于小波变换和WVD分布的互感器突变性故障协同诊断方法。借鉴站域思想,对变电站中的互感器划分协同甄别组,利用小波变换模极大值原理定位信号突变时刻。在有多个互感器因系统扰动出现干扰信号的情况下,依然能够利用WVD分布的良好时频分布特性将故障互感器从中辨识出来。在PSCAD中搭建仿真模型,验证了所提方法在突变性故障与系统扰动同时/不同时发生时均能够对故障互感器有效辨识。

In view of the lack of a solution to deal with abrupt-changing fault and abnormal disturbance signals in the existing transformer fault diagnosis methods,this paper presents a collaborative diagnosis of abrupt-changing fault of electronic instrument transformer based on wavelet transform and WVD.Based on the idea of station-area,the instrument transformers in substations are divided into cooperative discriminate groups,and the principle of wavelet transform modulus maxima is used to locate the sudden change time of signals.In the case of multiple transformers disturbing signal due to system disturbance,the fault transformer can still be identified by the good time-frequency distribution characteristics of WVD distribution.A simulation model is built in PSCAD to verify the effectiveness of the proposed method in identifying fault transformers when abrupt-changing fault and system disturbance occur simultaneously or at different times.