Resonant Push-pull Converter with Flyback Regulator for MHz High Step-Up Power Conversion
Abstract
With the trend towards achieving high efficiency, high power density and high operating frequency in power converters, a new circuit architecture is proposed in this paper for high step-up photovoltaic applications. This converter consists of a current-fed resonant push-pull converter (PP) as a DC transformer (DCX) dealing with most of power with high efficiency and an active clamp flyback converter (ACF) as a regulator within a large conversion range. As a single stage converter, the ACF regulator is paralleled with PP converter to share the total power and regulates the high output voltage. An experimental prototype with an input voltage range of 24 Vā32 V and output 400 V/400 W is built under 1 MHz switching frequency. A peak efficiency of 97.1% and a power density of 210 W/in3 (or 13 W/cm3) are achieved. Experimental result validates the correctness of the analysis and proves the feasibility of the proposed converter for MHz high step-up DC-DC conversion.