The application of wavelet singularity detection in fault diagnosis of high voltage breakers

The occurrence of mechanical failures of high voltage breakers not only can cause time shift of vibration impulse events, but also can bring the change of some wave crest shapes in time domain. In this paper, a novel technique is proposed to improve the accuracy of breakers´ fault diagnosis. Using Hilbert transform to pick up the envelops of vibration signals, and then disposing those envelops with multi-scale wavelet transform, the singularity exponents of those envelops are calculated by the signal singularity detection theory based on wavelet transform, and which are used as feature parameters of fault diagnosis. Though analyzing the vibration signals of high voltage breakers switching on and comparing the singularity exponents when they are in good condition and in fault condition, the conclusion could be deducted that preferable effect can be acquired if the singularity exponents are used in mechanical fault diagnosis of breakers