Single- and Three-Phase Dual-Active-Bridge DC-DC Converter Comparison for Battery Electric Vehicle Powertrain Application

Dual-active-bridge (DAB) DC-DC converters are of great interest for DC-DC conversion in battery electric vehicle (BEV) powertrain applications. There are two versions of DAB DC-DC converters: single-phase (1p) and three-phase (3p) architectures. Many studies have compared these architectures, selecting the 3p topology as the most efficient. However, there is a gap in the literature when comparing both architectures when single-phase-shift (SPS) modulation is not used to drive the converter. The aim of this study was to compare 1p and 3p DAB DC-DC converters driven by optimal modulation techniques appropriate for BEV powertrain applications. Mathematical loss models were derived for both architectures, and their performances were compared. A case study of a 100 kW converter was considered as an example to visualize the overall efficiency of the converter for each layout. The 1p DAB DC-DC converter architecture outperformed the 3p layout in both its Y-Y and D-D transformer configurations. The higher performance efficiency, lower number of components, and reduced design complexity make the 1p DAB DC-DC converter topology a favorable choice for BEV powertrain applications.