Comparison of Three Model Based Junction Temperature Control Systems to Increase the Lifetime of IGBT-Power-Modules

The lifetime of IGBT-power-modules is influenced by junction temperature swings which occur during alternating load conditions. This paper compares three different model based junction temperature control systems, which reduce the junction temperature swings. The difference lies in the correcting variables to manipulate the power losses these are a modulation strategy enabling specific durations of non-switching conditions of certain switches, a variable switching frequency and the presetting of a reactive current. These interventions do not have a negative impact to the demanded output power. The temperature control systems are operated at a two level three phase voltage source inverter feeding a permanent magnet synchronous machine. The considered field of application is the electric vehicle.