Torque ripple reduction for mutually coupled switched reluctance motor by bipolar excitations

This paper proposes a bipolar excitation scheme for a 6-slot and 8-pole (6/8) mutually coupled switched reluctance motor (MCSRM) to reduce torque ripple. Under the proposed excitation scheme, the 6/8 MCSRM is operated as a 6-phase machine. The excitation scheme proposed includes two excitation modes. A shift angle between coenergy profiles of the MCSRM under two excitation modes is studied based on finite element analysis (FEA). The bipolar excitation proposed in this paper reduces torque ripple with considering the shift angle, which is verified by finite element method (FEM)-based simulation results. The comparison of the torques produced by the MCSRM under one traditional single-phase, unipolar excitation scheme, one two-phase, bipolar excitation scheme, and the bipolar excitation scheme proposed is provided. The simulation results show that the method proposed effectively reduces torque ripple without sacrificing average torque produced by the MCSRM at the same current density.