Sensitivity analysis of behavioral MOSFET models in transient EMC simulation

This contribution investigates behavioral MOSFET models used for the simulation of conducted and radiated electromagnetic interferences (EMI) of an automotive inverter. A combined simulation of an equivalent circuit and the 3D geometry for a traction inverter based on 1.2 kV, 40 A SiC MOSFETs is presented. The model considers the MOSFET as a combination of parasitic elements of the package, voltage-dependent semiconductor capacitances, an internal gate resistance, the IV curves of the MOSFET and the diode. After verifying the model using measurements in the time and frequency domains, it is used to determine the influence of its parameters on the disturbance voltage at the line impedance stabilization network. The results identify the EMI-relevant parameters of the MOSFET and provide information on which data needs to be measured and which can be extracted from the datasheet of the MOSFET.