2026/05/07 by Ning Gao, Dingkuan Feng, Jianjun Ma +7
Engineering · #Advanced DC-DC Converters #Multilevel Inverters and Converters #Wireless Power Transfer Systems
paper · doi:10.1109/tpel.2026.3691223
openalex publication_date 2026/05/07 · openalex created_date 2026/05/08 · openalex updated_date 2026/07/30
To meet the requirement of asymmetrical bidirectional power transfer in solid-state transformer (SST) applications, this paper introduces an asymmetrical bidirectional active bridge (AB²) isolated DC-DC converter topology. The AB² converter topology incorporates a parallel connection of an active full bridge circuit and an uncontrolled diode-based rectifying bridge to achieve differentiated forward and reverse power transfer. Benefit from the utilization of diodes to replace the fully-controlled semiconductor switching devices in traditional symmetrically structured DC-DC converters, the total component cost can be reduced. Then a modulation strategy is presented in order to handle the transferred power of the AB2 converter, which also provides both circulating power suppression and wide zero voltage switching (ZVS) operation region characteristics. By adopting the unified phase shift duty ratio definition, smooth switching between different power flow conditions can be guaranteed. Design criteria for circuit parameter and closed-loop control strategy are further studied. Based on theoretical analysis, comparative analysis and conceptual design including four typical symmetrical / asymmetrical DC-DC topologies are carried out aiming to verifying the advantages of the AB2 converter topology. The calculation and simulation results demonstrate that AB2 converter possesses advantages in terms of cost, current stress, power losses, and system reliability. Finally, a downscaled AB2 converter prototype is implemented and tested for purpose of verifying the principle correctness and feasibility of the AB2 converter topology studied in this paper.