高功率密度永磁同步电机由于重量与体积小，输出功率大的特点，广泛地应用于人们的生产生活之中。而高功率密度电机发热量较大，因此对其温度场的计算成为了一项重要研究内容。本文以高功率密度永磁同步电机的温度场为研究对象，对其损耗、温度场计算以及冷却结构的优化设计进行了研究与分析。首先，对永磁同步电机的损耗计算方法开展了分析，采用电磁计算软件Maxwell完成电机的铁芯损耗、铜损耗与永磁体涡流损耗计算。并通过计算获得了电机各类损耗随电机转速和输出功率的变化关系。计算所得电机的各类损耗，作为热场计算中的热源，损耗计算也是进行电机温度场计算分析的条件基础，其次，介绍了电机热模型的等效与简化方法，建立了电机本体与冷却结构分离计算的温度场计算方法，通过流体计算软件FLUENT与有限元软件ANSYS完成电机温度场计算，并通过电机温升测试实验验证了模型以及计算的正确性。所建立的温度场计算方法是先采用流体计算软件进行水冷机壳的表面传热系数的计算，并折算成一个等效表面传热系数，再利用该等效系数，采用有限元软件进行电机本体的温度场计算。计算结果表明电机绕组端部温升最高。通过控制电机温升测试实验系统的冷却水流量与水温，进行多组温升测试实验，并与仿真计算结果对比，验证了计算方法的合理性。对仿真计算过程中涉及到的主要参数进行了敏感性分析，结果表明不同的参数对计算结果均有着不同的影响，该分析为电机温度场计算相关领域提供了具有实际应用价值的借鉴意义。最后，采用响应面优化设计方法，对电机圆周水道式水冷机壳进行了优化设计。通过对结构参数的分析，选取了电机水道数、水道宽度与水道高度作为优化设计因素，引入用于等效水道换热能力的系数作为响应。通过Design-Expert优化设计软件建立了优化设计分析表，并得到了三维响应曲面图与回归方程。分析表明，水道数量与水道宽度的增加有利于冷却能力的提升，而水道高度的增加则不利于冷却能力的提升。利用数学优化软件1stOpt工具包求解回归方程最优因素组合，并通过仿真计算验证了响应面模型的正确性。
High-power density permanent magnet synchronous motors are widely used in people's production and life due to their small weight and volume and large output power. However, as the heat generated by high power density motors is large, the study on the calculation of the motor temperature has become an important research content. In this paper, the temperature of high-power density permanent magnet synchronous motor (PMSM) is taken as the research object, and the loss, temperature and the optimization design method of its cooling structure is studied and analyzed.Firstly, the loss calculation method of PMSM is analyzed. The electromagnetic software Maxwell is used to calculate the iron core loss, copper loss and permanent magnet eddy-current loss of the motor. The relationship between various losses of the motor and the motor speed and output power is obtained through calculation. The calculated motor loss is applied as the heat source in the calculation of temperature and the loss is the conditional basis for calculating and analyzing the temperature of the motor.Secondly, the equivalent and simplified methods of the thermal model of the motor are introduced. And the calculation method of the temperature of the separate calculation of the motor body and the cooling structure was established. The temperature field calculation of the motor is completed by the fluid calculation software FLUENT and the finite element software ANSYS. And the correctness of the model and the calculation method are verified by the motor temperature rise test experiment. The temperature calculation method established is: first calculate the surface heat transfer coefficient of the water-cooled casing using fluid calculation software, and convert it into an equivalent surface heat transfer coefficient, and then use the equivalent coefficient to calculate the temperature of the motor body by finite element software. The calculation result shows that the highest temperature rise appears at the motor winding end. Multiple sets of the motor temperature rise tests were conducted by controlling the cooling water flow and water temperature in the motor temperature rise test system. It verifies the rationality of the calculation method compared with the simulation calculation results. The sensitivity analysis of the main parameters involved in the simulation calculation process was carried out. The results show that different parameters have different effects on the calculation results. This provides a practical reference for the field of motor temperature calculation.Finally, the circumferential water channel type of water-cooled casing of the motor was optimized and designed using response surface optimization design method. Through the analysis of structural parameters, the number of motor channels, channel width and channel height were selected as optimization design factors, and the coefficient used for equivalent channel heat transfer capacity was introduced as the response. Through Design-Expert optimization design software, the optimization design analysis table was established. And three-dimensional response surface graph and regression equation were obtained. The analysis shows that increasing the number of water channels and the width of the water channel is beneficial to the improvement of cooling capacity, while increasing the height of the water channel is not conducive to the improvement of cooling capacity. 1stOpt toolkit, a mathematical optimization software was used in solving the optimal factor combination of the regression equation, and the correctness of the response surface model was verified by simulation calculation.
