中文摘要：

表贴式无刷直流电动机的永磁体和紧圈如果采用电导率较高的材料，在时间和空间谐波的影响下可能会产生明显的涡流损耗。利用有限元法计算了紧圈分别采用不锈钢和碳纤维两种电导率不同材料表贴式无刷直流电动机的转子涡流损耗，基于计算得到的涡流损耗利用解析集总参数热网络法对两台电机进行了热场分析，并通过实验验证了仿真结果。通过研究发现，采用碳纤维紧圈的电机转子涡流损耗明显减小，转子发热有效改善。

英文摘要：

Due to relatively high electrical conductivity of permanent magnets and retaining sleeve of surface-mounted brushless DC machines, significant eddy current loss may be induced by both time and space magneto-motive force har- monics. In this paper, rotor eddy current losses of surface-mounted brushless DC machines with different sleeve materials, which were stainless steel and carbon fiber respectively, were calculated using finite element analysis. Thermal fields of the two machines were analyzed using analytical lumped-circuit method based on the obtained eddy current losses and the pre- dicted temperature rises of machines were verified by experiment results. The research reveals that the rotor eddy current losses of the motor with carbon fiber sleeve were significantly reduced the rotor temperature rise is improved effectively.