Comprehensive Method for Common-Mode EMI Analysis in Dual Active Bridge Converter

Increased transistor switching speeds and higher operating voltage ranges pose growing challenges in terms of electromagnetic interference (EMI). As DC systems gain popularity, EMI in these systems must also be considered. This paper discusses methods of analytical modeling of the common-mode (CM) noise source and develops a new, comprehensive method. Existing analytical CM noise models are refined, and the resulting model is compared with experimentally measured CM noise. Based on the model, the impact of the AC-link symmetry in a dual active bridge (DAB) converter is analyzed. The analysis considers the single phase shift (SPS) and extended phase shift (EPS) modulation schemes and compares them in terms of EMI and power efficiency, using an experimental DAB converter with a nominal power of 25~kW.