Identification of damaged rotor bar in induction motor based on transient analysis of start-up current using MODWT

The impact of a broken rotor bar on the induction motor’s stator current has been investigated in this paper. Its central concept depends on the discovery of distinctive features related to rotor faults in the time-frequency maps produced by the use of wavelet transform. The fundamental and the higher frequency components have been removed from the raw signal before the application of continuous wavelet transform (CWT) so that the expected fault signature can be easily identified. This is accomplished through the use of the maximal overlap discrete wavelet transform (MODWT), that dissolves the raw signal into several levels of detail and approximate levels containing specific frequency bands, and then reconstructs a signal using coefficients from some of those levels that capture only the frequencies of interest. This method based on start-up transient analysis allows for the avoidance of certain important drawbacks of the conventional MCSA, such as the difficulty in differentiating the closely placed fault frequencies and the likelihood of a wrong diagnostic. In 2D ANSYS Maxwell software, a machine model is created and faults are implemented and investigated. The effectiveness of the detection technique has been proven using real-time public data after first being tested on simulated data.