Reduction of Switching Frequency Vibration of Induction Machines by Auxiliary Winding With Capacitors

The switching action of power electronic devices causes high frequency current, magnetic field, vibration and annoying noise of induction machines fed by inverters, and these high-frequency components concentrate around the switching frequency and its multiple times. Adding auxiliary winding with capacitors is an effective way to reduce the high frequency vibration by weakening the high frequency magnetic field. In order to analyze the vibration mitigation effect of adding auxiliary winding with capacitors, this method is systematically and theoretically analyzed in the paper. The accurate equivalent circuit of induction machines with auxiliary winding is proposed considering the mutual leakage inductance between stator main winding and auxiliary winding. The transfer function of electromotive force and its frequency response are used to illustrate the effect of vibration reduction. To verify the correctness of the analysis, two induction machines with different auxiliary winding arrangements are prototyped and tested.