Patent ID: 11921161

Abstract:
A computer-implemented method is provided for detecting broken bar faults of an induction motor during operations. The method includes steps of acquiring, in a time domain, a signal of a stator current powering the induction motor with a fundamental frequency via an interface, wherein the induction motor is under a varying speed operation; converting the stator current to a complex space vector; transforming the complex vector to a transformed stator current by referencing to synchronous reference frame; performing Short time Fourier Transform (STFT) on the transformed stator current to get spectrogram matrix; removing a DC component from the spectrogram matrix; determining, in a frequency domain, sparse and smooth frequency components in the spectrogram matrix, wherein the determining includes a graph-based method by imposing a smoothness constraint and a sparsity constraint on the frequency component; and detecting a fault in the induction motor if the frequency component includes a continuously changing and sparse fault frequency component in the spectrogram matrix.