Analysis of Maximum Power Transfer Limit for Linear Operation of Dual-Active-Bridge Converters

In power electronics applications where the dual-active-bridge (DAB) converter topology serves as an isolation stage between high-impedance input and output ports, significant voltage fluctuations can arise during transient conditions. These variations restrict the DAB converter’s maximum power transfer capacity and narrow its linear operating region, a limitation further exacerbated when low-capacitance capacitors are used at the DAB converter terminals. This paper introduces a comprehensive control design framework tailored to maximize the DAB converter’s power transfer capacity, accommodating a range of input and output capacitor sizes. Additionally, we examine multiple control strategies that directly influence voltage variations at the DAB converter terminals, demonstrating their critical role when trying to maximize the DAB converter’s power capacity.