Model Based Junction Temperature Control Using the Gate Driver Voltage as a Correction Variable

Junction temperature swings, caused by load alternation in power electronics, lead to a reduced lifetime of power semiconductor devices. When temperature swings occur, the different material layers of the power semiconductor device expand in a different way because of their different coefficient of thermal expansion. The result is mechanical strain between these layers. Junction temperature control systems are able to minimize the occurring temperature swings and to smooth the junction temperature course. Thus, the expected lifetime of the power semiconductor device is extended. A possibility to affect the junction temperature and the value of the junction temperature are required to realize such a control system. This paper proposes a model based junction temperature control system for lifetime extension of the power semiconductor devices using the gate driver's supply voltage as a correction variable. Therefore, the junction temperature is calculated by a thermal model with the load condition as an input variable.