耿惠 李永建 栗浩森 杨占力

摘要 针对永磁电机的时间谐波和空间谐波引起电机中永磁体涡流损耗增加的问题，本文搭建了永磁体综合磁特性测试装置测量永磁体谐波激励下的动态涡流损耗，从磁特性角度解释了谐波产生大量涡流损耗的原因;又分别从理论分析、数值计算和磁特性测量实验验证的角度研究了抑制永磁体涡流损耗的方法-永磁体分割法。首先，分析了永磁体分割法抑制涡流损耗的原理。然后，建立了不同分割方式的永磁体三维有限元仿真模型，分析永磁体电流密度和涡流损耗随分块数的变化规律。最后，应用永磁体磁特性测量系统测量了不同分割方式永磁材料钕铁硼（NdFeB）的动态磁特性。结果证明在一定分割块数范围内，可以有效降低永磁体涡流损耗的80%。实际工况下，应根据永磁体有效尺寸及永磁材料利用率合理选择分块数。研究结果对永磁电机永磁体的结构优化设计有重要意义。

关 键 词 永磁电机;谐波;永磁材料;涡流损耗;磁特性测试;永磁体分割

中图分类号 TM351     文献标志码 A

文章编号：1007-2373（2021）06-0030-08

Abstract To solve the problem of increased eddy current loss in permanent magnet machines caused by time and space harmonics， this article builds a permanent magnet comprehensive magnetic properties test device to measure the permanent magnet dynamic eddy current loss under harmonic excitation， and explains the reason for the large amount of eddy current loss caused by harmonics from the perspective of magnetic properties. The article also analyzes the method to reduce eddy current loss of permanent magnet—permanent magnet segmentation from the perspective of theoretical analysis， numerical calculation and experimental verification. First， the principle of the permanent magnet segmentation method to suppress eddy current loss is analyzed. Then， 3-D finite element models of different segmentation methods of NdFeB are established to study the change of the current density and eddy current loss with segmentation numbers of permanent magnet. Finally， the dynamic magnetic properties of NdFeB permanent magnet materials adopting different segmentation methods are measured using the properties measurement system of permanent magnet. The results show that the eddy current loss of the permanent magnet can be effectively reduced by 80% under specific segmentation methods. Under actual working conditions， the number of blocks should be selected reasonably according to the effective size and the utilization rate of the permanent magnet. The results are of great significance in the optimization design of permanent magnet machines.

Key words permanent magnet machines; harmonic; permanent magnetic material; eddy current loss; the magnetic properties measurement; permanent magnet segmentation

0 引言

稀土永磁電机以其效率高、功率大、结构简单、节能效果显著等优点在工业生产和日常生活中得到广泛应用[1]。近年来，高耐热性、高磁能积钕铁硼永磁体的成功开发，使新型稀土永磁电机的研发取得突破性进展[2-3]。

由于永磁电机采用电力电子变换器驱动，会产生大量的时间谐波，电机分布绕组会在气隙中产生空间谐波，定子开槽引起的气隙磁导变化会在电机气隙中产生齿谐波，这些谐波会在永磁体中引起大量涡流损耗[4-6]。……