Design Adjustment Strategy of Switched Reluctance Machines for Resonance Avoidance

Vibration is most severe when the effective excitation harmonic of the SRM phases coincides with an eigenfrequency, which is also called resonance. Therefore, it is an effective way to reduce the vibration in the operating speed range by avoiding resonance during the machine design procedure. In this paper, a design adjustment strategy is proposed to avoid the resonances of switched reluctance machines at wide speed range. The effective excitation frequencies and eigenfrequencies are calculated by analytic formula and finite element method (FEM) respectively. Then the vibration analysis is performed to investigate the eigenfrequency that should be shifted. Finally, a modification equation is proposed to give a guidance of the selection of the modified stator yoke thickness. Simulation results verifies the feasibility of the proposed adjustment strategy.