A high step-up DC–DC converter based on triple-winding coupled inductor with ZCS and QR: operation principle, analysis, and verification

This paper presents a non-isolated high step-up DC–DC converter. The topology has been designed based on a triple-winding coupled inductor with the aim of improving the obtained voltage gain without requiring enlarged winding ratios and duty cycles. It benefits from high efficiency due to zero current switching (ZCS) and quasi-resonance operation (QR), as ZCS reduces the switching loss and QR operation eliminates the reverse recovery problem. The converter is suitable for renewable energy source applications due to input current continuity and common ground. Its power switch is placed at the low-voltage side and protected by a regenerative clamp circuit, preventing voltage spikes across the switch. As an approach, the topology performs better than its counterparts regarding the maximum switch voltage index. At the same time, other semiconductor devices encounter low-voltage stresses. The maximum capacitor voltage for most step-up converters equals the output voltage. As an approach, the output voltage divides between two capacitors in this converter, improving this index. This article exhibits the laboratory results of this topology as well as its theoretical principles. Results have been obtained from a 20V/200V/250W/60kHz prototype. Comparisons indicate that the converter is built at a lower cost than others.