Spectrum of a SiC MOSFET body diode for different junction temperatures and device currents

This DFG-sponsored research aims to develop precise and minimally invasive real-time monitoring technologies for SiC power modules that use the electroluminescence spectrum of the SiC body diode for device junction temperature and current sensing. After characterizing the electroluminescence spectrum of the SiC body diode for a wide operation range, different design options for sensors that extract the optical spectral information in real-time are developed and experimentally evaluated. In this context, an important research question is how the device current and junction temperature can be sensed independently from each other. For this purpose, system identification techniques, observers and machine learning technologies are combined to create new multi-physics monitoring solutions that obtain both variables with high bandwidth, low noise and the required precision. Finally, this research develops and investigates methods for power-module-integrated electroluminescence sensing based on fiber optics to monitor a multi-chip power module with minimized sensing effort.

The research funding of DFG enables the "Reliable Power Electronic Systems" group of ISEA to pursue the described research project within the "Center for Ageing, Reliability and Lifetime Prediction" (CARL) in Aachen over a period of three years. The research project shall enable precise electrothermal monitoring of future highly integrated power electronics with high bandwidth to protect SiC power modules from failures due to excessive thermal load or overcurrents.