High step‐up DC–DC converter based on coupled‐inductor for renewable energy systems

Abstract

The present study introduced a novel soft-switched high step-up DC–DC converter based on coupled inductors. The higher boost-factor is achieved relying on previous topologies by adjusting the turns ratio of the coupled inductors. Thus, the proposed converter provides a higher voltage gain with lower duty ratios. Two active clamp circuits are employed to clamp the voltage spikes resulted from parasitic inductances. This active clamp circuit provides zero-voltage switching turn-on operations and zero-current switching turn on/off operations for active switches and power diodes, respectively. In addition, the equivalent leakage inductance of the coupled inductors is placed in series with the power diodes, which significantly alleviates the reverse-recovery problem of diodes. The other features of the proposed topology include fewer components, low cost, small input current ripple, and the low voltage stress on power switches. Low voltage stress allows choosing a lower voltage rating metal–oxide–semiconductor field-effect transistor, which directly reduces the cost. The experimental results evaluated the performance of the proposed topology. For this purpose, a 48 V/380 V/500 W laboratory prototype was built and tested, and the results confirmed the performance of the presented converter.