Efficiency Optimization of a Series-Resonant Dual-Active-Bridge Converter with Voltage-Doubler Rectification

This paper investigates a dual-active-bridge (DAB) converter topology based on a voltage-doubler rectifier and series resonant network. By integrating phasor-domain analysis with time-domain modeling, a comprehensive mathematical model of the output voltage and instantaneous inductor current is established. The voltage gain expression is further refined by accounting for the effects of dead-time and power switch output capacitance. Based on this model, a multi-objective global optimization is performed, aiming to minimize reactive power, RMS current, and switch conduction losses, while simultaneously satisfying zero-voltage switching (ZVS) conditions and voltage gain requirements. Leveraging the optimization results, an extended phase-shift control strategy incorporating phase-shift feedforward and frequency closed-loop regulation is proposed. Experimental results demonstrate that the proposed topology achieves high efficiency across the entire operating range, with a peak efficiency of 96.92%. The results validate the effectiveness and engineering practicability of both the topology and the control scheme.