Fault diagnosis for SPD based on wavelet transform modulus maximum

Singularities often carry major information in voltage signals in the combination wave detection of SPD. Theory of singularities detection based on wavelet analysis can define the singularities according to the modulus maximum of wavelet analysis of voltage signals. Through analyzing the location and degree of modulus maximum, that there is any fault or not in SPD can be shown. This paper analyzes the voltage signals of different types of faults and discusses the method that diagnoses the SPD using wavelet transform modulus maximum. The test results show that this method is fairly effective in SPD fault recognition.