Detection Method Research Of Faults In Asynchronous Motors

The transient simulations of rotor bar breaking fault and stator winding inter-turn short circuit fault in asynchronous motors, as well as the related experiments, have been completed. By jointly using continuous subdivision Fourier transform, self-adaptive filter, digital band-pass filter and Hilbert transform technique, the radius of gyration is extracted from the stator current and chosen as the rotor bar breaking fault feature to detect this type of fault. As for stator winding inter-turn short fault, a detection method, which treats the stator current wavelet transform modulus maximum, phase difference and negative sequence component mutation signal as the fault features, is presented. Another detection method, which takes the filtered value of stator negative sequence apparent impedance as the fault feature, is also put forward. The former and latter are suitable for the asynchronous motor continuous/discontinuous monitoring system. At the same time, the bearing damage experiment has been carried out. And furthermore, a detection method, based on the wavelet packet "energy"of stator current, is proposed. Results of simulation and experiments demonstrate that the above-mentioned detection methods are valid and feasible.