Design of outer rotor IPM type PMSM for 3 wheel electric vehicle

In this paper, the optimization design of outer rotor IPM type PMSM was carried out for electric vehicle traction having 3 wheel system. The half round shape was proposed to reduce the cogging torque due to IPM machine characteristics. The object of optimization design is to find out most effective factor in reducing the torque ripple which may occurs the noise, vibration and uncomfortable riding of EV. In order to satisfy the low cogging torque, some design parameter such as air-gap, number of slot, poles, and slot open size was evaluated. From the simulation results of the outer rotor type IPM, we find out that the combination of slot open and depth of magnet is most important factor for reducing the cogging torque and high performance in low speed operational area. Moreover, the prototype of designed outer rotor IPM type PMSM was carried out and verified their properties.