Early-stage HF-EMC Simulation Analyses of Common-Mode Current in SiC-Based Motor Drive System for Modern Aircraft Applications

In modern aircraft applications, an electrical powertrain based on silicon carbide (SiC) modules is a promising technology for achieving commercial roadmap targets. However, the high switching speeds and parasitic elements associated with SiC-based power converters bring up drawbacks in terms of electromagnetic compatibility (EMC). Furthermore, during the early-stage design of a system, the prediction, optimization, and fast simulations to analyze EMC performances are not always easy tasks. It requires accurate models and is still continuously being treated in the literature. This article discusses and highlights the key elements responsible for EMC issues, in a typical common-mode (CM) current signature. A discussion and methodology on how several aspects of EMC, in terms of power energy, can be predicted in advance are also presented. A modeling approach through an improved equivalent CM circuit (ECMC) is introduced, providing satisfactory results and good computational time versus accuracy trade-off, even with ringing effects. The analyses presented here are suitable for EMC pre-compliance tests. Simulation results of a 2-level SiC-MOSFET prototype under development are presented to validate theoretical approaches. Experimental EMC tests in a 50 kW electromechanical chain with 70 kVA SiC-MOSFET prototype are presented for validation purposes.