Transient co-simulation of electromagnetic emissions caused by a SiC traction inverter

We present EMI simulations of a silicon carbide MOSFET traction inverter. The simulations are based on a transient circuit simulation and frequency domain simulations of different 3D geometry models. In a first step, an equivalent circuit is derived from parts of the geometry model and combined with an analytical model of the MOSFETs and an equivalent circuit model of the DC link capacitor. The results from the time domain simulation are used as input data for a frequency domain simulation in a second step. This part of the simulation is based on geometry models of the complete CISPR25 test setup including one monopole and one biconical antenna. The combination of both simulations can reproduce the conducted and radiated emissions of the inverter up to 110 MHz even if a filter network is added to the DC side of the inverter.