Novel approach for detection of inter-turn short circuit of induction motor's stator winding through envelope analysis

In this paper, a new approach for detection of inter-turn short in the stator winding of an induction motor is presented. Discrete Wavelet Transform using DB4 is performed on the envelopes of the windowed steady-state current signatures. The envelopes are determined by applying Hilbert Transform. Low frequency oscillations below 50 Hz were extracted from the reconstructed details at higher wavelet levels. As the envelope works on narrow band frequencies or mono-component signal, it was analyzed using higher wavelet levels which belong to the narrow band harmonics. The RMS and Mean values of the reconstructed details and Power Detail Energy defined as PDE were used as fault parameters to detect the faulty motor from the healthy one. It has been observed that the faulty motor produces higher fault parameters than the healthy one. Laboratory test results confirm the validity of the proposed method.