Purpose

Electromagnetic noise of permanent magnet synchronous motor (PMSM) seriously affects the sound quality of electric vehicles (EVs). This paper aims to present a comprehensive process for the electromagnetic noise analysis and optimization of a water-cooled PMSM.

Design/methodology/approach

First, the noises of an eight-pole 48-slot PMSM in at speeds up to 10,000 rpm are measured. Furthermore, an electromagnetic-structural-acoustic model of the PMSM is established for multi-field coupling simulations of electromagnetic noises. Finally, the electromagnetic noise of the PMSM is optimized by using the multi-objective genetic algorithm, where a multi-objective function related to the slot width of PMSM stator is defined for radial electromagnetic force (REF) optimization.

Findings

The experimental results show that main electromagnetic noises are the 8n-order (n = 1, 2, 3, …) and 12-order noises. The simulated results show that the REFs are mainly generated by the 8n-order (n = 1, 2, 3, 4, 5, 6) vibrations, especially those of the 8th, 16th, 24th and 32th orders. The 12-order noise is a mechanical noise, which might be caused by the bearings and other structures of the PMSM. Comparing the simulated results before and after optimization, both the REFs and electromagnetic noises are effectively reduced, which suggests that an appropriate design of stator slot is important for reducing electromagnetic noise of the PMSM.

Originality/value

In view of applications, the methods proposed in this paper can be applied to other types of PMSM for generation mechanism analysis of electromagnetic noise, optimal design of PMSM and thereby noise improvement of EVs.

中文翻译：

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电动汽车用永磁同步电动机电磁噪声分析与优化

目的

永磁同步电动机（PMSM）的电磁噪声会严重影响电动汽车（EV）的声音质量。本文旨在为水冷式永磁同步电动机的电磁噪声分析和优化提供一个全面的过程。

设计/方法/方法

首先，测量八极48槽PMSM在高达10,000 rpm的转速下的噪声。此外，建立了PMSM的电磁-结构-声学模型，用于电磁噪声的多场耦合模拟。最后，通过多目标遗传算法对永磁同步电机的电磁噪声进行优化，定义了与永磁同步电机定子槽宽相关的多目标函数，以进行径向电磁力优化。

发现

实验结果表明，主要的电磁噪声为8n阶（n = 1、2、3，…）和12阶噪声。仿真结果表明，REF主要是由8n阶（n = 1、2、3、4、5、6）振动产生的，尤其是8、16、24和32阶的振动。12阶噪声是机械噪声，可能是由PMSM的轴承和其他结构引起的。比较优化前后的仿真结果，可以有效降低REF和电磁噪声，这表明适当的定子槽设计对于降低PMSM的电磁噪声很重要。

创意/价值

针对应用，本文提出的方法可以应用于其他类型的永磁同步电动机，用于电磁噪声的产生机理分析，永磁同步电动机的优化设计，从而改善电动汽车的噪声。