A DC-DC Center-Tapped Resonant Dual-Active Bridge with Two Modulation Techniques

Abstract

Power converters with higher efficiency in a wide load range are important for reducing the overall energy consumption of renewable energy generation systems. A center-tapped LC series resonant dual-active bridge (LC-DAB) converter for DC-DC conversion is proposed in this paper. The proposed converter utilizes a center-tapped bridge to block reverse current and eliminate back flow power to reduce conduction losses. Two modulation methods for the proposed topology (i.e., fixed frequency modulation (FFM), and variable frequency modulation (VFM)) are proposed and analyzed. Both modulation methods can realize soft switch over the entire load range to reduce switching losses. In addition, the proposed modulation techniques guarantee soft switching for all devices and synchronous rectifier is realized by the center-tapped bridge to further reduce the conduction losses. Furthermore, a comprehensive comparison in terms of conduction losses and switching losses has been carried out to highlight the superiority of the proposed converter over the existing LC resonant converters. Finally, simulated and experimental results for a 1.5 kW prototype are presented to validate the theoretical analysis and performance of the proposed converter.

Review of Dual-Active-Bridge Converters With Topological Modifications

“…Also, the analysis can be simpler based on fundamental harmonic. DAB/DAB3 converters with resonant networks have been studied for more-electric aircraft power supplies [281], [286], battery chargers [283], [287], [288], hybrid generation systems [285], energy storage [289], [306], [308], grid-connected PV system [290], [291], renewable energy generation systems [295], [296], [301], [302], [305], [313], [314], fuel cells generation system [298], SST in hybrid micro-grid [299], and V2G systems [303], [304], [311], [312].…”

“…Similar to the topology in [247], the amplitude of the auxiliary current can be controlled by adjusting the turn-on time of the switch in the switch-controlled inductor network so that ZVS can be achieved without too much undesired reactive current. > IEEE TRANSATIONS ON POWER ELECTRONICS < LC resonant networks are adopted in the DAB topology with multi-winding transformers in [296]- [298]. In [297] and [298], the middle winding is linked to the split capacitor, resulting in a non-multilevel converter.…”