Cogging Torque Reduction Using Axial Pole Shaping in IPM Coaxial Magnetic Gear

In this paper, in order to improve the cogging torque in the radial flux magnetic gear with integer gear ratio, the axial pole skew technique has been used. This design reduces cogging torque by shaping the distribution of the magnetic field in the air gap of inner rotor in the axial and radial directions. In order to compare the proposed method, the optimal design of radial shaping in inner high speed rotor is also investigated. The introduced methods have been optimized using genetic algorithm in order to obtain the maximum torque density and the minimum cogging torque. The results are compared using 3-D finite element method and the superiority of the axial shaping method is shown in it.