Research on Steady-State Thermal Impedance Calculation and Junction Temperature Prediction of Welded IGBT

In order to promote the implementation of the “carbon peak and carbon neutrality” strategy, China's renewable energy industry has made a leapfrog development. IGBT has gradually become the core component of photovoltaic converters in photovoltaic power generation systems due to its fast switching speed, strong current carrying capacity, energy conservation and environmental protection advantages. However, due to long-term operation in harsh working conditions, IGBT modules experience severe fluctuations in their internal junction temperature, which accelerates the fatigue failure of the module. Therefore, it is particularly important to conduct research on transient thermal impedance calculation and junction temperature prediction of welded IGBT modules to improve their thermal reliability. This article takes the Infineon FF450R12ME4 welded IGBT as the research object, and combines thermal parameter theory calculation method and finite element model simulation method. By calculating the transient thermal impedance of the IGBT module and constructing the transient thermal impedance matrix, the transient junction temperature of the module is predicted, and it is pointed out that the dual chip heating prediction method is the optimal method for transient junction temperature prediction.