High step-up three-level DC–DC converter with three-winding coupled-inductor

Abstract

Due to the wide adoption of photovoltaic power generation, non-isolated high step-up DC–DC converters are becoming more and more popular. Among these converters, the switched/coupled-inductor-based converter is more attractive due to the fact that it has fewer power devices and a high efficiency. This paper presents a three-level high step-up DC–DC topology with a three-winding coupled-inductor. When compared with a conventional switched/coupled-inductor-based converter, a higher efficiency can be achieved, owing to low voltage stresses devices, fewer semiconductors in the power loop, lower current stresses, and ZCS of the main switches. The operating principle of the proposed topology is analyzed in detail via equivalent circuits, where a theoretical analysis is carried out using state space modelling. Experimental results obtained on a 24–300 V, 360 W lab prototype have verified the excellent performance of the proposed DC–DC converter.