It is significant to balances torque and vibration performance for the surface-mounted permanent magnet (PM) machines. This paper proposes a functional magnet structure to suppress the vibration response of integral-slot surface-mounted PM machines. At the same time, the torque ripple is also greatly reduced without sacrificing the average torque. Firstly, taking the 48-slot/8-pole PM machine as an example, the main sources of the air-gap radial force are analyzed based on the Maxwell stress equation. Thereby, the main PM flux density harmonic components that contribute to the radial force are pointed out. Secondly, the design method of different functional magnet structure is investigated. Then, the effects of different magnet shapes on the torque and vibration performances are compared. The result shows that the proposed sinusoidal+3rd-order harmonic injection functional magnet structure can effectively improve the vibration performance without sacrificing the average torque. Finally, the prototype of the 48-slot/8-pole PM with functional magnet structure is manufactured, and the experiments are carried out for validation.

中文翻译：

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功能磁体结构分析及减少整体槽永磁电机电磁振动

平衡表面安装永磁（PM）电机的扭矩和振动性能具有重要意义。本文提出了一种功能磁体结构来抑制整体槽表面安装永磁电机的振动响应。同时，在不牺牲平均扭矩的情况下，扭矩脉动也大大降低。首先以48槽8极永磁电机为例，基于麦克斯韦应力方程分析了气隙径向力的主要来源。由此，指出了对径向力有贡献的主要PM磁通密度谐波分量。其次，研究了不同功能磁体结构的设计方法。然后，比较了不同磁体形状对扭矩和振动性能的影响。结果表明，所提出的正弦+三阶谐波注入功能磁体结构可以在不牺牲平均扭矩的情况下有效改善振动性能。最后制作了具有功能磁体结构的48槽/8极永磁体样机，并进行了实验验证。