Reduced Order Thermal Modelling of Multi-chip Silicon Carbide Power Modules

Multi-chip silicon carbide (SiC) power modules are gaining in popularity due to high current demand in automotive applications. To ensure reliable operation of the power module, thermal coupling between adjacent dies needs to be considered when estimating junction temperature of the power device. Finite-element (FE) simulations can accurately estimate the effect of these mutual thermal interactions on the junction temperature of the power device. However, the increased complexity and computational cost of FE modelling makes it unsuitable for power converter simulations needing prolonged runtime. This paper presents a reduced-order modelling (ROM) approach for thermal analysis of power modules based on vector fitting in ANSYS Twin Builder. The model is validated through static as well as dynamic measurements on the power module. Lastly, the efficacy of the model to simulate mutual thermal coupling effects is demonstrated with PLECS simulations.