Total Backflow Power Minimization for Dual Active Full Bridge DC-DC Converters in Parallel

Aimed at the input parallel and output parallel (IPOP) dual-active bridge (DAB) dc-dc converters, this paper proposes an unbalanced-power-distribution scheme (UPDS) that considers the practical parameter deviation between DAB converters for minimizing the total backflow power. Firstly, combined with the characteristics of extended-phase-shift (EPS) control, the popular balanced-power-distribution scheme (BPDS) cannot achieve minimum backflow power due to the parameter deviation. In this regard, UPDS is established by detailed mathematical derivation, dividing the system operation into three sections. Simulation model and two-parallel DAB converters protype were built, and the results substantiated the validity of the theoretical analysis and the effectiveness of the proposed method.