A Structure-Reconfigurable Isolated Bidirectional DCDC Converter for Wide Voltage Gain Range Applications

In this article, a structure-reconfigurable isolated bidirectional dc-dc converter is proposed. This converter can be configured into four operation structures with different voltage gains, which is suitable for wide voltage gain range applications. Through unified phase-shift modulation, the bidirectional power transfer of different operation structures is able to be regulated, which has a simple parameter design and is easy to implement. In addition, the energy stored in the leakage inductance is absorbed and utilized with the operating state of the converter, thereby avoiding the voltage spikes caused by the leakage inductance. Also, the proposed converter achieves soft-switching operation of the switches, decreases the turns ratio of the transformer, and the power components (e.g., transformers, power switches, inductors, etc.) are partially enabled in different operation structures, thus implementing high conversion efficiency. The topology structure, operating principles, and design considerations are described in more depth, and an experimental prototype with 40-200 V on the low-voltage side and 400 V on the high-voltage side is established. The theoretical analysis and experimental results fully verify the correctness and effectiveness of the proposed converter.