VOLTERRA: An Innovative Approach for Accurate Nonlinear Thermal Modeling of Electronic Components

Thermal management is a critical challenge in the design of power electronic components, where nonlinear thermal effects induced by the temperature dependences of thermal conductivities can markedly impact both performance and reliability. This paper introduces VOLTERRA, an innovative model-order reduction (MOR) code that enables circuit-based thermal and electrothermal simulations accounting for nonlinear thermal effects. Unlike conventional methods, VOLTERRA leverages a partition-based hyperreduction algorithm founded on Volterra's series expansions, achieving finite-element method (FEM)-grade accuracy with computational complexity scaling linearly with the number of heat sources. The proposed method is validated on a 1.2 kW SiC-based power module; more specifically, it is shown that VOLTERRA achieves negligible temperature estimation errors with respect to reference results obtained through timeconsuming nonlinear FEM simulations.