Mutual coupling and its effect on current and torque of six phases Switched Reluctance Motor

In this paper, two kinds of torque ripple optimization methods are proposed for Switched Reluctance Motors due to the mutual coupling between phases. When phase number of SRM is more than two, SRM is often running in status of two phases excited simultaneously, then mutual inductance will be occurred between phases. The mutual coupling will affect the current waveform, thereby affecting the torque. This paper take a six phase 12/10 SRM as an example, four kinds of arrangements of stator magnetic polarity based on the two kinds of winding connections is given and the asymmetry of the magnetic distribution in the four modes is described. For NNSS arrangements of stator magnetic polarity, the phenomenon of asymmetry currents and the resulting torque ripple is analyzed using finite method. Based on the analysis of mutual inductance, the limitations of stator and rotor poles arc is given and an asymmetric control strategy is proposed to reduce the torque ripple. The simulation shows that the average torque is increased and the torque ripple is reduced.