Abstract: To improve reliability of traction converter and save cost, the mission profiles-based lifetime prediction was performed on the IGBT modules, the key component in traction system. Firstly, the electro-thermal model was built and the junction temperature of IGBT was obtained under two different full-speed range control schemes of induction motor (IM), which based on current open loop and single current close loop flux weakening control respectively. Then, the rain-flow counting method was adopted to extract the junction temperature information (including the fluctuation and maximum of junction temperature) of thermal cycles that IGBT suffered from. Finally, the Miner linear accumulation damage theory was employed to calculate the damage of IGBT caused by each thermal cycle, and the lifetimes of IGBT were predicted under two different control schemes. The simulation results show that the full-speed range control scheme based on single current close loop flux weakening control can effectively improve the lifetime of IGBT and thus improve the reliability of traction system.

Key words: insulated gate bipolar transistor (IGBT) modules, lifetime prediction, mission profiles, traction inverters, reliability