Broken rotor bar detection using empirical demodulation and wavelet transform: suitable for industrial application

Abstract

This paper proposes a new approach for stator current analysis, based on empirical demodulation (ED) and discrete wavelet transform, for detection and diagnosis of broken rotor bars in three-phase induction motors under low and high slip conditions. Unlike the traditional motor current signature analysis, the method proposed is not dependent on the load and a higher spectral resolution obtained from a larger acquisition time when the motor operates at low slip condition. In this work, firstly, the motor steady-state current signals are filtered using a band-pass filter. Then, the modulation components are extracted using a demodulating technique recently proposed (ED). Finally, the modulator signals are decomposed via wavelet transform and are analyzed by using a derived orbit shape. Computer simulations and experimental tests demonstrate the superior performance of the proposed method. It is simple and easy to implement.