电动汽车电机控制器IGBT结温计算方法与验证

Calculation method of IGBT junction temperature for electric vehicle motor inverter and its verification

电动汽车电机控制器中的主要热源是绝缘栅双极型晶体管(insulated gate bipolar transistor,IGBT)模块,其最大结温的高低是影响控制器可靠性的关键因素。为保证IGBT模块最大结温始终在其允许工作温度范围内,采用水冷方式对其进行散热。文章以某款纯电动汽车电机控制器为研究对象,结合传热学基本原理,提出了一种水冷散热器热阻估算方法,并用该方法得到的热阻值直接对IGBT模块结温进行计算;为验证计算方法的有效性,利用数值模拟的方法对水冷散热器内部流场以及IGBT结温进行仿真分析,同时进行试验测试,并将得到的3组结果进行对比。结果表明,该文提出的计算方法可以准确地得到IGBT在不同工况点的结温。

Insulated gate bipolar transistor(IGBT) module is the main heat source of the electric vehicle motor inverter, and its maximum junction temperature is the key factor that affects the reliability of the inverter. To ensure that the maximum junction temperature of the IGBT module is always within its allowable operating temperature range, it is cooled by the water cooling system. Taking an electric vehicle motor inverter as research object, combined with the basic principle of heat transfer theory, a method for estimating water cooling radiator thermal resistance is put forward, and then the IGBT junction temperature is calculated directly from the thermal resistance. In order to verify the validity of the method, the numerical simulation method is used to simulate the flow field of water cooling radiator and the IGBT junction temperature, and the experiment is also carried out. By comparing the results, it is concluded that the junction temperature of IGBT at different operating conditions can be calculated accurately by this method.