High Voltage Gain Dual Active Bridge Converter with an Extended Operation Range for Renewable Energy Systems

Developing bidirectional dc-dc converters has become a critical research topic and gains more and more attention in recent years due to the extensive applications of smart grids with energy storages, hybrid and electrical vehicles and dc microgrids. In this paper, a Partial Parallel Dual Active Bridge (P2DAB) converter, i.e. low-voltage (LV) side parallel and high-voltage (HV) side series, is proposed to achieve high voltage gain and low current stress over switching devices and transformer windings. Given the unmodified P2DAB power stage, by regulating the phase-shift angle between the paralleled active bridges, the power equations and voltage gain are then modified, and therefore the operation range can be extended effectively. The operating principles of the proposed converter and its power characteristics under various operation modes are studied, and the design constraints are discussed. Finally, a laboratory prototype is constructed and tested. Both simulation and experimental results have verified the proposed topology’s operation and design.