Diagnosis of broken rotor bar in induction machines using pitch synchronous wavelet transform

Most often, broken rotor bar (BRB) frequency components are hardly detected in the stator current due to its low magnitude and its closeness to the supply frequency component. In this paper, a new approach is applied to overcome this drawback based on Pitch synchronous wavelet Transform (PSWT) under lower sampling rate. Compared to the traditional filtering techniques such as notch filter, PSWT can eliminate completely the fundamental frequency and doesn´t cause any suppression at the frequency sideband. The use of a lower sampling rate is an important factor to optimize the cost and the computation time of the diagnosis systems. Statistical results show that the proposed method has a good performance to detect BRB under different load conditions and different fault severity.