基于小波包分解的逆变器—相开路故障诊断

摘要

By introducing the double fourier transform of the switch function, the frequency spectrums of inverter' s DC side current were analyzed, and the frequency related to the open fault of two transistors was educed. The RMS value of the wavelet packet decomposition coefficients of DC side current was calculated, and could be the symptom of open fault. The experimental results demonstrated that the proposed approach was feasible.%应用开关函数的双傅里叶变换技术,分析逆变器的直流侧电流的频谱,得出逆变器一相开路故障时的故障特征频率.利用小波包分解的分频特性,对逆变器直流侧电流信号进行小波包分解,求得故障特征频率相应子频带的小波包分解系数的均方根值,并将其作为逆变器一相开路故障的故障特征,以此作为逆变器一相开路故障诊断的依据.试验结果证明了该方法应用于逆变器一相开路故障诊断的可行性.