Achieving EMC Compliance in Traction Inverters via Multiobjective Optimization

Achieving first-time-right electromagnetic compatibility (EMC) is crucial in automotive industry for competitiveness. However, compliance with EM emission limits is usually evaluated through measurements on hardware prototypes, especially for complex system like electric vehicle (EV) powertrains, which include multiple components such as traction inverters (TIs) that collectively contribute to the overall emissions. Furthermore, several design goals, such as the amount of magnetic material or total installed filter capacitances, must be considered. Therefore, this paper introduces a simulation framework based on common- and differential-mode emission surrogate models with 16 design parameters. The models are derived from a circuit simulation model valid up to$30 \,\mathrm{M}\mathrm{Hz}$and enable the prediction and optimization of conducted emissions (CEs) of traction inverters in the concept phase, prior to hardware prototyping. A Two-Level Traction Inverter (TLTI) system and CISPR 25 standard limits serve as an example. According to the feature selective validation (FSV) metric, the surrogate models achieve a worst-case accuracy rated as “very good” for CE prediction when trained on a dataset of 8064 samples. This corresponds to a spectral uncertainty of approximately$\pm 2 \,\mathrm{dB}$. With evaluation times of about$15 \,\mathrm{m}\mathrm{s}$, the presented surrogate models allow to perform 100 million TI optimizations in just$48 \,\mathrm{h}$, resulting in three selected optimal designs verified by circuit simulations. Therefore, the framework acts as a potential tool to develop first-time-right EMC and performance optimized prototypes.