Abstract: With the development of vehicle electrification, the research and development of heavyload vehicles is also developing in the direction of high mobility and electric drive. In view of the overtemperature alarm problem of the power unit in the use process of an electric drive overloaded vehicle, this paper first analyzes all the sports car data of the vehicle, and studies the common working conditions of the power unit and the design margin of each radiator. Secondly, the modified design objectives of engine water dispersion and motor and controller water dispersion are proposed to increase 10% and reduce 10% respectively. Finally, the height of the engine and the motor and controller are redesigned. After the redesign, the height of the engine is increased to 1.12 times of the original size, and the height of the motor and controller is reduced to 0.94 times of the original size. The improved radiator meets the design requirements and is used well.

Key words: electro driven heavy-duty; power units; cooling system; design improvement

摘要： 随着车辆电动化的发展，重载车辆的研发也在向高机动、电驱方向发展。文章针对某 电驱重载车辆在使用过程中出现的动力单元过温报警问题，首先针对车辆全部跑车数据进行 分析，研究了动力单元常用工况和各散热器的设计裕度情况。其次对发动机水散和电机及控 制器水散分别提出了增加 10%和降低 10%散热功率的修正设计目标。最后通过试验与仿真相 结合的方法，对发动机水散和电机及控制器水散的高度进行了重新设计。重新设计后的发动 机水散高度增加至原尺寸的 1.12 倍，电机及控制器水散高度减小至原尺寸的 0.94 倍，改进后 的散热器满足设计要求并使用良好。

关键词: 电驱重载；动力单元；冷却系统；设计改进