| In order to improve the reliability of high-power power converters, the temperature monitoring of high-power insulated gate bipolar transistors (IGBT) modules is required. So far, there have been few studies on high-voltage IGBTs in this field. In this paper, a dual-pulse experimental platform is built , and the thermal-sensitive electrical parameters of the 4.5 kV and 1.2 kA IGBT modules during switching transients are measured. The online junction temperature extraction and expected cost for each parameter are discussed. The results show that most parameters are strongly dependent on the load current and bus voltage in addition to temperature. The most suitable junction temperature extraction parameters are the quasi-threshold voltage and the collector current rate of change at turn-on. They can be obtained by the parasitic inductance of the IGBT.