Modulation Scheme of Dual Active Bridge Converter for Seamless Transitions in Multi-working Modes Compromising ZVS and Conduction Loss

Abstract

A modulation scheme for dual active bridge (DAB) converter is introduced to achieve ZVS and reduce the conduction loss in this chapter. To compromise the ZVS achievement and the conduction loss, optimized working modes are derived from different cases. However, the converter can not achieve seamless transient among the optimized working modes, which may cause the instability. A modulation scheme employing closed-loop control by integrating different working modes is introduced. Furthermore, the seamless transition among the different working modes can be achieved, so the modulation scheme is very suitable to be used for wide battery voltage and wide load requirements. The conduction loss and peak current by using the presented modulation scheme are compared with those of other modulation schemes. With the presented modulation scheme, both the conduction loss and ZVS can be improved. Finally, a 1.2 kW experimental prototype has been built to verify the effectiveness of the converter and the modulation scheme.