Dynamic and static performance optimization of dual active bridge DC-DC converters

High efficiency and fast dynamic response are two main control objectives for dual active bridge (DAB) DC-DC converters. Traditional extended phase shift (EPS) control can significantly enhance the conversion efficiency of DAB DC-DC converters by reducing current stress; however, it cannot fulfill fast dynamic response requirements. In this paper, a novel hybrid control scheme consisting of EPS control and direct power control (DPC), named as EPS-DPC, is proposed. EPS-DPC control has salient features in both efficiency and dynamic performance. In order to verify the outstanding performance of the proposed EPS-DPC scheme, an experimental comparison was carried out on a scale-down DAB DC-DC converter among several control strategies, including single phase shift control with traditional voltage-loop (SPS-TVL), EPS control with traditional voltage-loop (EPS-VTL), and EPS-DPC. Experimental results have been high consistent with theoretical analysis, and verified these advantages of the proposed EPS-DPC scheme.