The Effects of the Permanent Magnet on the Performance of a Permanent Magnet Synchronous Motor Under Various Operating Conditions

Rare-earth permanent magnet synchronous motors (PMSMs) are commonly used in new energy vehicles, wind power generation, and other relevant fields due to their advantages of small size and high power density. The operation of this type of motor depends on a rare-earth permanent magnet. However, the compatibility between the permanent magnet and the motor under different motor operating conditions is unclear, which is unfavorable for the subsequent selection of motor magnets. In this study, the effects of the permanent magnet on motor performance in different operational environments were analyzed. Three different magnets, namely, N-52M, N-48SH, and SmCo-28H, were selected. Two types of operational conditions were selected: the motor temperature and input current. The load torque, the magnet’s demagnetization behavior, and the magnet’s cost-effectiveness were discussed. The results indicate that the N-52M magnet was suitable for a low temperature and low input current due to its high remanence. However, the SmCo-28H magnet should be used at high temperatures and input currents due to its superior anti-demagnetization properties. The results obtained in this study will enable comparison of the effects of different permanent magnet materials on the motor, thereby guiding the subsequent design of PMSMs.