A Multi-Timescale Coupled Simulation Framework for Power Electronic Systems and the Piecewise Analytical SiC MOSFET Transient Model

The role of switching transients has become increasingly critical in power electronic systems, particularly with the growing adoption of wide-band-gap devices such as silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). This evolution necessitates the coupled simulation of nanosecond- to microsecond-scale device-level transients alongside millisecond- to second-scale system-level behaviors. This paper proposes a multi-timescale coupled simulation framework for power electronic systems that eliminates additional system dimensions and stiffness introduced by the parasitic parameters of SiC devices, thereby resolving convergence issues and enabling high simulation speed. A piecewise analytical switching transient model is developed to provide closed-form expressions for the proposed framework. A double-pulse test (DPT) platform is constructed to validate the accuracy of the model across various SiC devices, gate drive configurations, and load conditions. Additionally, the conductive electromagnetic interference (EMI) of a 10 kHz/170 kW inverter system is simulated as a case study to demonstrate the proposed approach's ability to support the coupled simulation of device-level dynamics and system-level operation in power electronic systems.