DWT wavelet transform for the rotor bars faults detection in induction motor

The detection of broken rotor bars faults based on the analysis techniques, such as the fast Fourier transform (FFT), the accuracy of these technique depend on the loading conditions of the machine, and the ability to maintain a constant speed. To over come this problem, the analysis of the envelope of the transient starting-current waveform using the wavelet transform has been investigated. In this paper, a method for the diagnosis of rotor bar failures for the induction machine has been presented. It is based on the analysis of the stator current, using the discrete wavelet transform (DWT) at the start-up electromagnetic torque. Using the simplified dynamic model taking account the faults of the squirrel cage induction motor and the discrete wavelet transform (DWT), in order to extract the different harmonics 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 rotor bars).