Thermal Monitoring of Power Electronic Modules with Minimal Sensing Effort

Abstract

This work proposes a technique that enables the accurate real-time monitoring of junction temperatures and 3-D distributed temperatures in power modules with minimal sensing effort. For that purpose, a 3-D electrothermal real-time model and the temperature information of an integrated nonlinear temperature thermistor are effectively combined in a thermal estimator. The proposed technology is easy to implement for most power converters and has key advantages in comparison to thermal real-time models. It decouples the temperature estimation process from inaccuracies of the thermal model between the base plate and the coolant. Furthermore, it either does not require a coolant temperature sensor or it enables the detection of DCB to base-plate solder degradation or deterioration of the convection process, e.g. due to blockages. The monitoring solution is evaluated on the basis of simulations and experiments with a state-of-the-art automotive power module.