A high-precision realization of online junction temperature estimation

The on-state voltage at high current is very suitable as a sensitive parameter for junction temperature monitoring. But there are still problems in applications, such as accuracy, noise, temperature drift, and verification. In this paper, an accurate online sampling module was designed. A compensation method was adopted to improve the sampling accuracy of the existing current sensor. With a novel sudden-stop control strategy, an offline junction temperature measurement is used to verify the online monitoring results. Finally, an experimental verification is carried out on a 600V/ 250kW three-phase inverter system.