Wide input high step-up isolated DC/DC converter

The isolated step-up DC/DC converter is a kind of converter that can convert low DC voltage bus into high DC voltage bus and realize electrical isolation.This technology has been widely used in new energy generation,such as fuel cell power system and micro-inverter system.Its research focuses on wide input adaptation,high step-up and high efficiency power conversion.LLC resonant converter perfectly satisfies these requirements.For this reason,high step-up DC/DC converter based on full bridge LLC resonant converter was studied in this paper.Two structures were presented,namely,single-stage structure applying regulated LLC resonant converter and two-stage structure applying Boost converter cascaded unregulated LLC resonant converter.The design method of the resonant tank under different structures based on the optimal magnetizing inductance was proposed.Finally,the prototypes of regulated and unregulated LLC resonant converter were built to verify the verification of the proposed method.