Measurement of IGBT Junction Temperature in DC Circuit Breakers Based on Saturation Voltage Drop

The Insulated gate bipolar transistors (IGBT) plays a critical role in ensuring the reliability of DC circuits, particularly in relation to circuit breaker performance. Junction temperature, an internal attribute of IGBTs, can be accurately measured to effectively detect IGBT working performance and ensure optimal circuit operation. However, existing junction temperature measurement methods are highly invasive, with large margins of error and complex operations, making them unsuitable for circuit breaker working environments. This paper focuses on measuring the saturation voltage drop of an insulated-gate bipolar transistor (IGBT) to reflect the internal junction temperature and explores a online measurement suitable for short circuit testing in direct current (DC) circuit breakers. And the feasibility of online measurement is both simulated and experimentally verified. The influence of short circuit current on junction temperature measurement is also discussed through simulation and experiment, showing that it should be taken into account during the measurement process. By exploring the IGBT saturation voltage drop as a means of measuring the junction temperature, this paper provides a reliable method for measuring IGBT junction temperatures in DC circuit breakers.