高速永磁无刷直流电机损耗优化设计研究

Loss Optimization of High-speed Permanent Magnet Brushless DC Motor

为提高便携式电动检修工具的续航能力并减少其发热,需要降低电动工具驱动用高速永磁无刷直流电机的损耗。本文提出一种通过结合定子裂比和铁心磁通密度优化实现损耗最小的BLDCM设计方法。构建了BLDCM的电磁模型,推导出铜耗、铁耗等损耗与定子裂比及铁心磁通密度的解析关系,求解使总损耗最小化的定子裂比与铁心磁通密度最佳组合。以一台20000 r/min的高速无刷直流电机为例,通过有限元仿真和实验测试对所提优化方法的准确性进行了验证。仿真和试验结果表明,所提BLDCM优化设计方法可以有效获取最优定子裂比和磁场强度,进而确定电机最优方案,使电机损耗最小。

To improve the endurance of portable electric maintenance tools and reduce its heating,it is necessary to reduce the loss of high-speed permanent magnet brushless DC motors(BLDCM)used for driving electric tools.This paper proposed a design optimization method to minimize the loss by optimizing split ratio and core magnetic flux density(Bm).This method deduced the analytical relationship between losses,split ratio and Bm by building an electromagnetic model.The optimal combination of split ratio and Bm was calculated analytically to minimize the loss.A BLDCM with rated speed 20000 r/min was researched in this paper.The accuracy of the optimization method was verified by finite element simulation and experiment.These results confirmed the accuracy of the proposed method,the optimal scheme can be achieved and the loss can be minimized.