Fault Detection Wavelet Fractal Method of Circuit of Three-Phase Bridge Rectifier

A wavelet and fractal method is presented to detect opening fault of power electronic circuit based on singularity of fault signal from power electronic equipment. Voltage wave signals of variable faults are multi-scale decomposed by wavelet transform. The correlative dimensions of high frequency signals of wavelet transform are computed in different fault state, which are used to determine the fault types of apparatus. The fault position of apparatus is judged by the emergence time of singularity. At last, the algorithm of fault recognition is presented. Simulation results show the method is practical.