Characteristic analysis of asynchronous motor fault signal based on wavelet packet decomposition

This paper presents characteristic frequency analysis of asynchronous motor fault signal based on wavelet packet decomposition. Asynchronous motor´s current and vibration signals are acquisition objects, Fault diagnosis is based on frequency information contained in motor´s signals. The wavelet packet decomposition (WPD) method is applied to extract their characteristic frequency, and then it´s necessary to ascertain WPD layers according to signal sampling frequency and the requirement of frequency resolution. A method is put forward, which characteristic frequency is located quickly to node in the WPD layer. It may promote the application of wavelet packet analysis method in motor fault diagnosis system.