Comparison of Modulation Strategies for a Dual Active Bridge Partial Power DC-DC Converter in EV Powertrains

Abstract

Electromobility has been growing rapidly in recent years, as a result of green and sustainability policies that promote it, but its growth has been hampered by having less autonomy than combustion vehicles, not being able to directly replace them especially in heavy-duty electric vehicles powertrains. The main objective of this work is to propose an improvement to an already implemented Bidirectional Dual-Active-Bridge (DAB) Partial Power Converter (PPC) topology, seeking to boost efficiency by testing different modulations. The modulation study applied to PPC is interesting in order to identify the cases where the RMS current in the transformer is minimized. Results of the study shows that efficiency of the DAB-based PPC can be optimized by using the correct modulation, with a possible maximum efficiency of 99.41% at 6.526 kW.