Method of EMD and ZOOM-FFT to detect the broken bars fault in induction motor

For the fault signal processing of induction motor with broken rotor, a new processing method is proposed, which is based on Empirical Mode Decomposition(EMD) and zoom fast Fourier transform (ZOOM-FFT). Using this method can make up the shortcomings that the frequency resolution of the general Fast Fourier transform (FFT) has a certain limit in the frequency range of interest. And the EMD adopted in this method has better adaptability. The stator current signal which is after low-pass filter processed is firstly decomposed with Empirical Mode Decomposition, and a series Intrinsic Mode Function (IMF) components which include different features scale are gained. Then, the IMF component which contains the broken bar fault feature is spectrum analyzed by using ZOOM-FFT. At last the fault feature frequency component can be picked up to judge the broken bars fault according to the amplitude of the fault component. The stator current analysis result from the simulation and actual measurement demonstrate the validity of the proposed method.