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

This paper presents a simple and generic model of a dual active bridge converter valid throughout its range of operation. It is suitable 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 (<inline-formula><tex-math notation="LaTeX">$d_1$</tex-math></inline-formula>, <inline-formula><tex-math notation="LaTeX">$d_2$</tex-math></inline-formula>) of the two full-bridge converter ac voltages and the phase shift (<inline-formula><tex-math notation="LaTeX">$\phi$</tex-math></inline-formula>) between them can be decomposed into four parallel dual active bridge circuits operating in simple phase-shift modulation. The hypothesis is proven mathematically; the average and small-signal models are derived and validated through simulations and experiments on a hardware prototype.