Online junction temperature estimation for IGBT modules with paralleled semiconductor chips

This presentation describes methods for the online estimation of the junction temperature (Tj) for IGBT modules with paralleled semiconductor chips, with each chip operating at different junction temperatures. Experimental and simulation results are presented. The Tj estimated from the gate-emitter voltage (Vge) during the IGBT switch-off process was found to be very close to the average junction temperature of all the semiconductor chips in the IGBT module. The Tj estimated from the dVce/dt slope at lower voltages was found to represent the highest temperature of all the semiconductor chips in the IGBT module.