基于子域法的永磁体周向分段式转子涡流损耗解析模型

Analytical model for eddy current loss of permanent magnet circumferentially segmented rotors based on subdomain method

工程上常将永磁体分段来减小自身涡流损耗,减小高温退磁的风险。现有永磁体分段的转子涡流损耗解析模型大多忽略涡流反作用影响,应用于高速永磁电机转子涡流损耗计算会造成较大误差。本文基于子域法提出了一种针对永磁体周向分段的高速永磁电机转子涡流损耗解析方法。在考虑定子开槽和各次电流谐波影响的基础上,通过引入考虑各次谐波透入深度的衰减系数对涡流密度进行修正,进而考虑涡流反作用的影响。基于该解析模型,分析了电枢磁场中转子涡流损耗随永磁体分段数的变化规律。将有限元仿真计算结果与解析结果对比,验证解析模型的正确性。

In engineering,permanent magnets are often segmented to reduce their own eddy current losses and reduce the risk of high-temperature demagnetization.Most of the existing analytical models for eddy current losses in segmented permanent magnet rotors ignore the effect of eddy current counteraction,which can cause significant errors when applied to the calculation of eddy current losses in high-speed permanent magnet motors.This article proposes an analytical method for eddy current losses in high-speed permanent magnet motor rotors based on the subdomain method,which targets the circumferential segmentation of permanent magnets.On the basis of considering the stator slot and the influence of each current harmonic,the eddy current density is modified by introducing the Attenuation coefficient considering the penetration depth of each harmonic,and then the influence of eddy current counteraction is considered.Based on this analytical model,the variation of rotor eddy current loss in the armature magnetic field with the number of permanent magnet segments is analyzed.In this paper,the finite element simulation results are compared with the analytical results to verify the correctness of the analytical model.