A Convenient Temperature Estimation Method for Half-Bridge of RC-IGBT with One Monitoring Unit

Abstract

Temperature monitoring of power devices is critical for control optimization and health management. However, existing monitoring methods require a monitoring unit for each device, which increases complexity and cost. The reverse conducting insulated gate bipolar transistor (RC-IGBT) has great advantages in practical application, such as high power density. A convenient temperature estimation method for RC-IGBT half-bridge using one monitoring unit is proposed in this paper. The peak reverse recovery current of the diode increases with the junction temperature. The peak reverse recovery currents of two bridge arms can be measured via turn-on collector current overshoot and turn-off collector current overshoot of one bridge arm. The temperatures of IGBT and free-wheeling diode (FWD) are close for RC-IGBT. Therefore, the temperatures of two bridge arms can be estimated with one monitoring unit. The method proposed provides a simple and convenient monitoring structure. The experimental results validate the feasibility of the proposed technique.