新能源汽车扁铜线绕组电机槽内绝缘等效导热系数分析与计算

Analysis and calculation of equivalent thermal conductivity of slot insulation system of flat copper wire winding motor for new energy vehicle

新能源汽车永磁驱动电机(PMDM)功率密度的不断提升对电机散热性能提出了更高的要求,定子绕组绝缘系统的传热特性是控制电机热点温度的主要瓶颈。针对定子齿槽、扁铜线绕组和绝缘材料的尺寸偏差及渍漆填充率对车用扁铜线绕组永磁驱动电机定子槽内绝缘系统传热性能的影响,提出了定子槽内绝缘系统等效导热系数的计算方法,并据此开展了尺寸偏差和工艺参数的参数敏感性分析。采用电磁场、温度场与流体场的耦合分析方法,利用槽内绝缘等效导热系数,研究了绕组损耗分布差异时具有不同导热能力绝缘材料的扁铜线绕组电机不同工况下的温度分布。完成两台110 kW样机的制造及测试。仿真与实验结果的对比分析验证了提出的定子槽内绝缘系统等效导热系数计算方法的准确性。

With the continuous improvement of the power density of permanent magnet drive motor(PMDM)in new energy vehicles,higher requirements are put forward for the heat dissipation performance of the motor,and the heat transfer characteristics of stator winding insulation is the main bottleneck to control the highest temperature of the motor.The parameter sensitivity analysis of dimension deviation of stator slot,flat copper wire winding and insulating material and paint process on heat transfer performance of stator slot insulation system of vehicle PMDM was analyzed,and the calculation method of equivalent thermal conductivity of insulation system in stator slot was put presented.Using the coupling analysis method of electromagnetic field,temperature field and fluid field,and equivalent thermal conductivity of insulation system in stator slot,the temperature distribution of flat copper wire winding motors with different heat conductivity insulation materials under different working conditions was studied considering the difference of winding loss distribution.Two 110 kW prototypes were manufactured and tested.The comparison between simulation and experimental results verifies the accuracy of the proposed method for calculating the equivalent thermal conductivity of the insulated system.