基于最优控制策略的逆变器散热结构优化

为了提高电动汽车用永磁同步电机逆变器IGBT模块的可靠性,文章从热损耗和散热两方面对逆变器可靠性进行研究。首先通过对比分析永磁同步电机在同一工况下d轴电枢电流为零(id=0)和最大转矩电流比(MTPA)两种控制方式下逆变器中IGBT模块的损耗,发现MTPA控制策略优于id=0控制策略;接着,基于MTPA控制策略,设计了一种热管和风冷相结合的散热结构,相较原风冷散热结构,采用新型散热方式可使芯片最高工作温度降低8.49℃;最后,采用最优拉丁超立方抽样构建响应面代理模型(RSM),并采用多岛遗传算法(MIGA)对代理模型进行优化处理。经仿真验证,优化处理后的“热管+风冷”散热结构使得芯片最高温度又降低了15.12℃,有效提升了IGBT模块的热可靠性。

Heat Dissipation Structure Optimization of Inverter Based on the Optimal Control Strategy

In order to improve the reliability of the IGBT module used in the inverter for permanent magnet synchronous motor of electric vehicle,this paper studied the reliability of the inverter from two aspects:heat loss and heat dissipation.Through the loss comparison analysis of the IGBT module in the inverter under the same condition of d-axis armature current zero(id=0)and maximum torque per ampere(MTPA),it is found that the MTPA control strategy is better than the id=0 control strategy.Then,based on the MTPA control strategy,a heat pipe and air cooling combined cooling structure was designed.Compared with the original air cooling structure,the new cooling method can reduce the maximum working temperature of the chips by 8.49℃.In this paper,the optimal Latin hypercube sampling is used to construct the response surface surrogate model(RSM),and the multi-island genetic algorithm(MIGA)is used to optimize the surrogate model.It is verified that the optimized heat pipe air-cooled heat dissipation structure reduces the maximum chip temperature by 15.12℃,which effectively improves the thermal reliability of the IGBT module.