Switched-coupled inductor DC-DC converters

In this paper, a family of high efficiency high step-up dc-dc converter is presented, which inherits all advantages of both switched-inductor dc-dc converter and coupled-inductor dc-dc converter. The proposed converters can achieve high step-up capability with the proper duty cycle D (high or small D leads to the bad efficiency), obtain soft-switching conditions of active devices (including switch and rectifier diodes), and recycle the energy of leakage inductance to the output capacitor, which results in the high efficiency. The switch of converter operates in ZCS turn-on condition, which decreases the switching loss and improves the switch operating environment. The rectifier diodes cut off with ZCS condition, which improves the reverse recovery characteristics of diodes. The voltage relationships, operating principle, and operating modes are described in detail. Finally, experimental results verity the validity of the proposed switched-coupled inductor boost converter.