DC-DC converter with high gain and low input current ripples is an essential requirement of  DC power system such as photovoltaic and energy storage systems. This paper proposed a dual coupled-inductor based bidirectional two stage DC-DC converter. The main structure of converter adopts input parallel output serial (IPOS), which can not only reduce input current ripple, but also increase voltage gain. Introduction of double coupled-inductor and voltage multiplying unit can further increase the voltage gain, and decrease power switch voltage stress as well as widen suitable applications of power switches. During step-down mode, the power switches are fully controlled, whichcan obtain greater step-down voltage ratio to avoid extreme duty cycle. The simulation results prove the correctness and feasibility of the proposed topology.
 

High gain;Low ripple;Bidirectional DC-DC;Fully-controled;Coupled-inductor