Digital twin of intermediate layer temperatures observation of IGBT modules

IGBT module requires accurately intermediate layer temperatures (ILT) monitoring to ensure system safety and reliability. Considering critical failure factor of solder layer voids, this paper implements real-time monitoring to IGBT module ILT using DT. By deriving the nonlinear relationship between thermal resistance of solder layer and junction temperature, a mathematical model is refined to more precisely reflect the actual thermal behavior of IGBT. A nonlinear intermediate layer temperatures observer is designed to further improve the accuracy. Experimental validation demonstrates that, the proposed observer significantly enhances the precision with an error of only 0.1% compared to traditional methods.