An Approach to Unified Full-Order Modeling of Dual Active Bridge Type Converters

Modeling of dual active bridge (DAB) type converters, and that of its single-phase form, is an active area of research. In this paper, a new modeling approach is proposed. It is theorised that single-phase DAB converter operating in any of its multiple modes and modulation may be modeled as four dual active half-bridge (DAHB) circuits operating in simple phase-shift modulation. It allows extension of the model developed for simple phase-shift modulated DAHB converter to any operating mode of the DAB converter. In this respect, the physical basis of the theory is first explained. Subsequently, the improved first harmonic approximation (I-FHA) model of the DAHB converter, developed a priori, is extended to the general operating case of the DAB converter. Finally, the model is validated through extensive simulation and hardware experiments proving the theoretical basis of the proposed approach.