基于轴线方向不等宽度磁极结构的表贴式永磁同步电机极频振动的削弱

针对一台10极12槽表贴式永磁同步电机的极频振动问题，提出了一种轴线方向不等宽度磁极结构的削弱方案。该方案可以在保证电机转矩密度前提下，有效降低电机的极频振动。首先，根据麦克斯韦张量法，推导出电机径向电磁力的解析表达式，并建立了作用在电机定子齿部电磁力模型；同时，对样机中产生极频电磁力谐波的因素进行了分析研究。然后，通过有限元仿真分析，介绍了利用轴线方向不等宽度磁极结构降低极频电磁力的基本机理，并对优化前后的电机的电磁性能和振动加速度进行了比较分析。最后，研究结果表明，采用轴线方向不等宽度磁极结构能够有效地减弱极频电磁力谐波和振动，同时保持电机的转矩密度，证实了优化方案的有效性。

Reduction of Pole Frequency Vibration in Surface-Mounted Permanent Magnet Synchronous Motors Based on Axially Unequal Width Pole Structure

In order to solve the pole frequency vibration problem of a 10-pole and 12-slot surface-mount permanent magnet synchronous motor, a weakening scheme of the pole structure with axially unequal width is proposed. This scheme can effectively reduce the extreme frequency vibration of the motor under the premise of ensuring the torque density of the motor. Firstly, based on the Maxwell stress tensor method, an analytical expression for the radial electromagnetic force of the motor is derived, and a model of the electromagnetic force acting on the stator teeth of the motor is established. Simultaneously, factors contributing to the generation of pole frequency electromagnetic force harmonics in the prototype are analyzed. Then, through finite element simulation analysis, the basic mechanism of reducing pole frequency electromagnetic force by using the magnetic pole structure with axially unequal width is explained. And comparison analysis of the motor′s electromagnetic performance and vibration acceleration before and after optimization is conducted. Finally, the results show that the polar structure with axially unequal width can effectively reduce the harmonics and vibrations of the polar electromagnetic force while maintaining the torque density of the motor, which confirms the effectiveness of the optimization scheme.