高速永磁无刷直流电机的热分析

为了解决高速永磁无刷直流电机温升过高带来的磁性能降低及绕组绝缘破坏等问题,对高速电机的温度分布及改进措施进行了一系列研究.采用集中参数法建立了电机热网络数学模型,推导出电机损耗、热导和温度之间的解析方程;建立了基于ANSYS/Workbench的电机三维有限元模型,对其进行稳态热分析,从而得到电机整体的温度分布,验证了电机热网络模型的正确性;提出了改变转子护套材料及电机轴打孔两种措施.分析结果表明:改进后的电机转子部分温度有了明显降低,其中护套温度降低了约34℃,永磁体约54℃,解决了电机的局部温度过高问题.

Thermal analysis of high speed permanent magnet brushless DC motor

In order to solve the problems of reduction in magnetic performance and winding insulation damage caused by high temperature in high speed permanent magnet brushless DC motor,a series of research on temperature distribution and improvement was carried out.The thermal network mathematic model was established by lumped parameters method.And an analytic equation accounting for the relationship among motor loss,thermal conductance and temperature was derived.Besides,the motor 3D finite element model was built based on the ANSYS/Workbench,and steady-state analysis was conducted.The temperature distribution of the whole motor was achieved,which verified the results of thermal network model.And two methods including changing the retaining sleeve material and drilling holes on shaft were proposed to solve the temperature problem.According to the analysis results the rotor temperature has dropped obviously,especially the retaining sleeve and permanent magnet with a temperature decrease of about 34℃ and 54℃ respectively.