Resonant frequencies and mode shapes of switched reluctance motors

The wide application of switched reluctance motors (SRM) is limited by their higher vibration and acoustic noise. An accurate determination of resonant frequencies and mode shapes of the SRM stator is therefore essential for low acoustic noise design. Based on the structural finite element method and elasticity theory, 3D vibration modes and resonant frequencies of a 5 HP SRM with 8/6 poles are demonstrated and calculated in this paper The stator stack with both a smooth frame and a ribbed frame are examined. The effects of an encased frame and a keyed frame on the free vibration modes and resonant frequencies of SRM stator are compared. Accelerometer test results on a SRM verify some of the numerical computations.