An Automated Field-Circuit Coupling Simulation Method Based on PSpice-MATLAB-COMSOL for SiC Power Module Design

Multiphysics simulation software is indispensable for silicon carbide (SiC) power module design. Lacking interface between circuit simulation software and thermal-fluid-mechanical simulation software poses challenges for accurate design of the power modules. In this article, an automated field-circuit coupling simulation method based on the self-developed COMSOL-PSpice interface software is proposed to achieve precise and fast multiphysics cosimulation of multichip SiC power modules. First, the multiphysics coupling mechanism of SiC power modules is analyzed to reveal that the precise and timely data transfer between temperature and power loss is crucial to enabling an accurate multisoftware cosimulation. To realize the automatic data transfer between COMSOL and PSpice, a MATLAB-based software interface is developed. Then, a multirate and indirect coupling strategy is proposed to improve the simulation accuracy of the developed COMSOL-PSpice software interface and speed up the cosimulation process. To break the limitations of the indirect coupling strategy on simulation accuracy and efficiency with fixed time steps, a variable time step coupling analysis method based on the numerical solution of temperature coupling state variables is proposed. Finally, the proposed field-circuit coupling cosimulation method is verified by simulation and experiment results from a buck converter. The comparison between simulation and experimental results demonstrates the validity of the developed cosimulation interface software, which gives a mismatch below 5% and simulation efficiency 3–5 times higher, if compared to that using fixed time steps.