Influence of Rotor Tooth Shaping on Cogging Torque of Axial Flux-Switching Permanent Magnet Machine

Abstract

This paper proposes a rotor tooth shaping method to reduce the cogging torque of an axial flux-switching permanent magnet machine. The rotor tooth is shaped in different configurations, including constant, trapezoidal, asymmetrical, extended, and square shapes to evaluate the effects on cogging torque ripple minimization. A three-dimensional (3-D) finite-element analysis (FEA) is performed to compare the proposed shapes of the rotor tooth. Peak-to-peak cogging torque, fundamental flux linkage, loaded torque, and the total weight of teeth are compared using various rotor tooth angles. The simulation results show that overall minimum cogging torque is achieved by the extended shape of the rotor tooth. 3-D FEA results are also verified with experimental results.