Automatic voltage and dead time control for efficiency optimization in a Dual Active Bridge converter

A control scheme is developed in which efficiency is optimized over a wide range of loads for a Dual Active Bridge (DAB) converter. A simple control strategy is proposed to adjust both the converter conversion ratio and switching dead times to maintain high efficiency in the presence of varying loads. To demonstrate feasibility of the proposed control method, experimental results are presented for a 150-to-12 V, 120 W, 1 MHz prototype converter which has 97.4% peak efficiency and maintains greater than 90% efficiency over a load range between 20 W and 120 W.