考虑温度场和流场的永磁同步电机折返型冷却水道设计

Design of Reentrant Cooling Channel in Permanent Magnet Synchronous Motor Considering Temperature Field and Flow Field

针对永磁同步电机应用广泛的折返型水道结构,对一台额定功率68 kW的永磁同步电机建立流-固耦合的温度场、流场数值仿真模型来准确计算电机的温升与压降,并通过电机温升、压降实验对模型的正确性进行验证。然后利用该模型分析了水道中流体的流动特性,建立入水口水道宽度、水道圆角半径与水道压降的关系,得到当入水口水道宽度为45 mm,水道圆角半径为20 mm时水道压降最小,电机温升得到改善。通过对水道结构参数设计前后的样机进行温升及水道压降台架实验,测得经过设计后的电机绕组温升降低8.4℃,水道压降减小13.1%。

Based on the reentrant cooling channel which is widely used in permanent magnet synchronous motor,the temperature and water pressure of motor are simulated by a numerical simulation model of fluid and solid coupling for a 68 kW motor,and the motor temperature and water pressure experiments are carried to verify the accuracy of the model.Then the flow characteristics of fluid in the channel is analyzed by using this model,and the relationship between width of the water channel,channel radius and the pressure drop are established.When the width of inlet water channel is 45 mm and the fillet radius of the channel is 20 mm,the pressure drop of the channel is minimum,and the temperature rise of the motor is improved.After the optimization of the channel structure parameters,the temperature rise and pressure drop test of the prototype are carried out,temperature rise of the optimized motor winding is reduced by 8.4℃and the water pressure drop of the channel is reduced by 13.1%.