Nonisolated ZVT two-inductor boost converter with a single resonant inductor for high step-up applications

Abstract

The interleaved operation of a two-inductor boost converter system is a very attractive solution for converting the low input voltage (30-50 V) of distributed power sources, such as photovoltaic and fuel cells, to the high output voltage (380-760 V) required in grid-connected power-conversion applications. However, a soft-switching method is required in the two main switches to increase the overall power conversion efficiency. This paper proposes a zero-voltage-transition (ZVT) two-inductor boost converter using a single resonant inductor to meet these needs. To satisfy the requirement of soft switching in the two main switches, a resonant cell is constructed at the output side with a bidirectional switch, two auxiliary diodes, and a single resonant inductor. This converter has the advantages of simple circuitry, reduced size, and low cost due to a single resonant inductor. The validity of the proposed ZVT two-inductor boost converter is verified through experimental results.