转矩脉动是影响电机性能的重要因素。针对常规的内置式永磁电机转矩脉动较大的问题，提出了一种保持永磁体总量不变的不等磁极组合方法，使某一磁极的极弧长度与其他磁极不同来抑制转矩脉动，给出了详细推导过程和磁极参数确定方法，并与斜槽结构做了性能对比。针对外转子内置式结构，对比分析了隔磁桥和磁障两种隔磁措施，建立了有限元模型对其进行仿真验证。最终研制了一台55 kW，2 500 r/min的样机，试验数据与仿真结果相吻合，验证了所提方法对齿槽转矩和反电动势谐波有着显著削弱效果，能够有效抑制转矩脉动，提高电机性能，具有一定工程实际意义。

Torque ripple is an important factor affecting the performance of motor. Aiming at the problem of large torque ripple in normal interior permanent magnet motors, an unequal magnetic pole combination method keeping the total amount of permanent magnet unchanged is proposed. The method makes the pole-arc length of a magnetic pole different from other magnetic poles to suppress torque ripple. The detailed derivation process and the determination method of magnetic pole parameters are given, and the performance is compared with the skewed slot structure. Aiming at the interior structure of the outer rotor, two magnetic isolation measures of magnetic bridge and magnetic barrier are compared and analyzed, and the finite element modeling method is established for simulation and verification of the structure. Finally, a 55 kW, 2 500 r/min motor is developed, and the experimental data are consistent with the simulation results, verifying that the proposed method has a significant weakening effect on cogging torque and back electromotive force (EMF) harmonics. It can effectively suppress torque ripple and improve the motor performance and has practical engineering significance.