Series Resonant DC-DC Converter With Dual-Mode Rectifier for PV Microinverters

Abstract

A new series resonant dc-dc converter is proposed for PV microinverters. Compared to the conventional series resonant converter (SRC), a dual-mode rectifier (DMR) is configured on the secondary side, which allows the proposed converter to achieve a wider gain range with a fixed-frequency phase-shift control. Moreover, the active switches and diodes are turned on with zero-voltage switching (ZVS) and off with zero-current switching (ZCS), respectively, thereby minimizing the switching losses. The operation principle is firstly detailed and then the converter characteristics are analyzed and compared. Finally, a 400-kHz 250-W converter prototype is built and tested to verify the advantages of the proposed converter.