Vce-based chip temperature estimation methods for high power IGBT modules during power cycling — A comparison

Temperature estimation is of great importance for performance and reliability of IGBT power modules in converter operation as well as in active power cycling tests. It is common to be estimated through Thermo-Sensitive Electrical Parameters such as the forward voltage drop (V_ce) of the chip. This experimental work evaluates the validity and accuracy of two V_ce based methods applied on high power IGBT modules during power cycling tests. The first method estimates the chip temperature when low sense current is applied and the second method when normal load current is present. Finally, a correction factor that eliminates the series resistance contribution on the V_ce measured at high current, is proposed.