Assessing electric vehicle inverter to reduce energy consumption: using insulated gate bipolar transistor module to prevent the power loss and junction temperature

Abstract

In order to cope with the energy crisis and solve environmental pollution problems, electric vehicles (EV) have been widely promoted worldwide. EV can not only reduce the emission of polluted gases, but also reduce energy consumption. In order to ensure the reliability of the drive system of EV, it is very important to study the reliability of insulated gate bipolar transistor (IGBT) module in the drive system. This study developed a method for swift calculation of power loss and junction temperature curves of an IGBT module of an EV inverter. The steps of proposed calculation method are as follows: (1) the mapping relation between the EV running state and the IGBT module on-state current and duty ratio was deduced; and (2) the power loss calculation model together with the thermal network model, the average power loss and junction temperature curve in each switching cycle were obtained. To evaluate the accuracy of the proposed method, this study compared the calculations of the proposed method with Infineon’s online simulation tool, and found that the difference in average power loss is 3.23 W, and the difference in junction temperature average is 7.65 °C. The differences between the results are within a reasonable range, which shows that the proposed model can be used as a quick, alternative method for calculating the IGBT module’s power loss and junction temperature curves in the set driving process. Junction temperature periodic mean and amplitude extracted from the junction temperature curves can be used to calculate cumulative damage, which can be beneficial for IGBT lifetime prediction. In addition, this method can be used to analyze the influence of other relevant factors on power loss and junction temperature during the EV driving process.