Influence of Gate Loop Inductance on TSEP-Based Junction Temperature Monitoring for IGBT

In this article, the influence of gate loop inductance on the insulated-gate bipolar transistor (IGBT) junction temperature monitoring based on the transient peak gate current temperature-sensitive electrical parameter (TSEP) methods is investigated using the time-domain analysis, SPICE simulation, and experimental work. It is observed that the peak gate current decreases considerably with increasing gate loop inductance, which was not addressed by a previous work. An improved junction temperature estimation model is developed to address this issue and is experimentally validated over a wide range of gate loop inductances. Unlike the previously reported model calibrated for a fixed gate loop inductance, the new model can provide accurate junction temperature monitoring in any power converter based on the same IGBT with a wide range of gate loop inductance values. An error of less than 6.2 °C in IGBT junction temperature estimation is demonstrated even when the gate loop inductance varies by 247%.