等体积错位分段永磁电机电磁优化及降振减噪

Electromagnetic optimization and vibration and noise reduction of equal volume staggered segmented permanent magnet motor

关键词:  内置U型永磁同步电机  转子辅助槽  降振减噪  多目标遗传算法  Halbach充磁  转矩优化

Key words:  interior U type permanent magnet synchronous motor  rotor auxiliary groove  vibration and noise reduction  multi-objective genetic algorithm  Halbach magnetization  torque optimisation

摘要:

为提高内置U型永磁同步电机电磁性能同时降低电机周身振动噪声,提出聚磁式等体积错位分段内置U型永磁同步电机。首先,推导电机气隙磁通密度、空载反电动势及输出转矩等电磁性能表达式和径向电磁力、振动速度、加速度等电磁振动表达式。其次,探究单独增设磁障结构、错位结构和Halbach充磁结构对电机电磁性能影响。最后,对电机结构参数进行分析及寻优,对比5种U型磁极永磁同步电机电磁性能、电磁振动和噪声波动。研究结果表明,所增设4种结构对电机性能影响明显,电磁性能方面,增设磁障、错位结构和辅助槽能提高电机输出转矩降低齿槽转矩,Halbach充磁能改善输出转矩、径向气隙磁通密度分布以及径向电磁力分布,三者结合可使电机输出转矩得到提升,输出转矩更加平滑,齿槽转矩和转矩脉动降低明显；振动噪声方面,增设辅助槽结构大幅抑制径向电磁力8、16次谐波幅值；增设磁障结构能抑制电机低频振动加速度,增设错位结构和Halbach充磁能抑制电机高频振动加速度,4种结构配合可使空间8、16次径向电磁力明显下降,在时间4倍频和6倍频振动加速度得到明显抑制,电机最大声压级及机械强度满足电机运行要求,并加工出永磁电机转子样件。

Abstract:

To improve the electromagnetic performance of the interior U-shaped permanent magnet synchronous motor and reduce the vibration noise of the motor body, a magnet-focusing type equal volume misalignment segmented interior U-shaped permanent magnet synchronous motor is proposed. First, the electromagnetic performance expression of the motor such as gap magnetic flux density, no-load back-emf, and output torque, and the expression of electromagnetic vibration such as radial electromagnetic force, vibration velocity and acceleration are derived. Second, the effects of the separate addition of magnetic barrier structure, misalignment structure, and Halbach magnetization structure on the electromagnetic performance of the motor are investigated. Finally, the structure parameters are analyzed and optimized, and the electromagnetic performance, electromagnetic vibration, and noise fluctuation of 5 types of U-shaped magnet pole permanent magnet synchronous motors are compared. The study shows that the four added structures have a significant effect on motor performance. In terms of electromagnetic performance, the addition of a magnetic barrier, misalignment structure, and auxiliary can improve the motor output torque and reduce the slot torque. The Halbach magnetization can improve the output torque, radial air-gap magnetic flux density distribution, and radial electromagnetic force distribution, and combination of the three can improve the motor output torque. The output torque becomes more smooth, and the slot torque and torque ripple are significantly reduced. In terms of vibration noise, the auxiliary slot structure is added to significantly suppress the 8th and 16th harmonic amplitude of the radial electromagnetic force; the magnetic barrier structure can suppress the low-frequency vibration of the motor, and the misalignment structure and Halbach magnetization can suppress the high-frequency vibration acceleration of the motor, and the four structures can significantly reduce the radial electromagnetic force the space of 8 and 16 times, and the vibration acceleration of 4 times and 6 times in time is significantly suppressed, the maximum sound pressure level and mechanical of the motor meet the requirements of motor operation, and the rotor sample of the permanent magnet motor is machined.