A Simple Unified Model for Generic Operation of Dual Active Bridge Converter

The paper presents a simple and generic model of a dual active bridge converter valid throughout its range of operation. It is accurate for all operating modes and modulation strategies such as phase-shift, extended phase-shift, dual phase-shift or triple phase-shift modulation. It hypothesizes that any mode of its operation characterized by the duty ratios (d1, d2) of the two full-bridge converter AC voltages and the phase-shift (φ) between them can be decomposed into four parallel dual active bridge circuits operating in simple phase-shift modulation. Furthermore, the hypothesis is proven mathematically; the average and small-signal models are derived and validated through simulations and experiments on a hardware prototype.