Application of the fourier and the wavelet transform for the fault detection in induction motors at the startup electromagnetic torque

In this paper, a method for the diagnosis of rotor bar failures for the induction machines has been presented. It based on the analysis of the stator current, using the Fourier transform and discrete wavelet transform (DWT) at the start-up electromagnetic torque. Using the simplified dynamic model of the squirrel cage induction motor taking account the broken rotor bars and the discrete wavelet transform (DWT) in order to extract the different harmonic components of the stator currents. The performance presented by using of the DWT: its ability to provide a local representation of the non stationary current signals for the healthy machine and with fault (two adjacent broken bars). The results are compared with those obtained using the Fourier transform.