Compensation of cogging torque for flux-switching permanent magnet motor based on current harmonics injection

The flux-switching permanent magnet (FSPM) machine exhibits the advantages of high power density and large torque capability. However, due to the high airgap flux density produced by magnets and the doubly-salient structure, the resultant cogging torque is relatively large, which is unfavorable for high performance drive system. In this paper, instead of conventional optimization on the motor itself, a new control method is proposed in which current harmonics are specifically added into the reference current to produce an additional torque component which is used to compensate the fundamental and 2nd order harmonic components of cogging torque. Experimental evaluations of the proposed scheme are carried out on a dSPACE-controlled FSPM motor drive platform and the test results confirm the effectiveness of the proposed method. It should be emphasized that this method can be applicable to all PM machines having relatively higher cogging torque.