Design and optimization of cogging torque in stator permanent magnet axial-field flux-switched hybrid excitation motor based on RSM-CS algorithm

The cogging torque in stator permanent magnets axial-field flux-switched hybrid excitation motor (SPMAFHEM) is larger than the traditional PM machine because of the flux focusing. In order to reduce cogging torque and improve the performance of the motor, the analytic expression of the SPMAFHEM cogging torque is deduced by energy perturbation method and the influence of the structure parameters on cogging torque is researched. Based on response surface methodology (RSM) and FEM, the mathematical model of cogging torque response surface between stator slot arc width, rotor tooth inclination angle, and shape coefficient of permanent magnet is obtained, then the cuckoo search algorithm (CS) is used to search the optimum solution. The accuracy is examined by 3D FEM and experiments using prototype experimental platform. The results show that the cogging torque has been reduced by 82.5%.