基于磁热双向耦合的永磁电机损耗和温升分析

为了研究永磁电机材料（铜、钕铁硼）的温度特性对高速永磁电机的损耗和热性能的影响，在考虑电机部件装配间隙的基础上，提出一种磁-热双向耦合方法，根据电机电磁场实际损耗分布加载到其温度场中，绕组、永磁体等部件损耗随温度变化情况实时更新至电磁场，通过3-D瞬态有限元方法实现电机电磁场-温度场的多重迭代收敛计算。以一台15kW高速永磁电机为例，通过两种（磁-热双向、磁-热单向）不同的计算方法对该类电机在不同供电条件（正弦波供电及变频器供电条件）下的损耗及温升计算结果与样机试验结果进行对比和分析。结果表明，通过磁-热双向耦合方法所获得的结果与实验结果更为一致，验证了所提出的磁-热双向耦合法的准确性及优势，为提高该类电机损耗和温升计算精度提供指导。

Analysis and Research on Loss and Temperature Rise of PMSMs Using Electromagnetic-thermal Bi-directional Coupling

To research the impact of temperature-dependent characteristics of windings and magnets on the electromagnetic power loss and thermal properties of high-speed (HS) permanent magnet synchronous machines (PMSMs), an electromagnetic-thermal bi-directional coupling method (BDCM) was proposed on the basis of considering the assembling gaps between the motor components in this paper. The electromagnetic power loss is calculated by 3-D transient finite-element method and loaded into the 3-D temperature field according to the actual loss distribution, and the materials’ properties are in turn updated according to the temperature distributions. Taking a 15kW HS PMSM as an example, the loss and temperature calculation results are calculated by two different coupling methods in the conditions of the rated-load sinusoidal supply and converter supply, and compared with the measured results in the case of converter supply. The results obtained by the BDCM are more consistent with the experiment results, verifying the superiority of the proposed analyzing method in improving the calculation accuracy of motor loss and temperature rise. The BDCM proposed in this paper provides guidance for improving the calculation accuracy of the loss and temperature rise of HS PMSMs.