小波变换在短路故障检测中的应用

Application of Wavelet Transform on Detection of Short Circuit Fault

小波变换克服了傅里叶变换不能对信号同时进行时频局部化分析的局限性,具有很强的提取信号特征的能力。提出一种基于单向递推算法的故障信号检测方法:先从原始信号中提取基频电流信号,再提取基频电流信号的高频分量,通过测量高频分量的幅值突变点断定故障点。经过MATLAB仿真分析,证明这种方法可不受噪声和高频振荡影响准确检测出故障发生的时间。

Wavelet transform overcomes Fourier＇s limitations which can＇t analyze the signal in time and trequency regions at the same time, which has the strong ability to extract the feature of signal. A detection method that is based on single direction recursive wavelet transform is presented. Firstly, this method extracts basic frequency current signal from the original signal, then it extracts high frequency signals from basic frequency current, at last, it figure out the moment of the failure by scale the swing variety of high frequency signal. This method is proved by MATLAB simulation analysis, it can exactly figure outthe moment of the failure without affected by the yawp and the high frequency undulation.