An Input-Series Flyback Converter With the Coupled-Inductor-Based Passive Snubber for High-Input Voltage Multiple-Output Applications

摘要

In this paper, an input-series flyback converter with the coupled-inductor-based passive snubber is proposed, where the input-series converter is based on transformer integration, and the passive snubber is composed of inductors, capacitors, and diodes. The inductors of the snubber in various series modules are made on a common magnetic core, and the coupled-inductor scheme is adopted. With the help of the coupled inductor, active input voltage sharing of the input-series converter can also be achieved after the switches are turned OFF, and voltage sharing of the switch in each seriesmodule can be ensured, which overcome the shortcomings of the existing inputseries flyback converter. Active voltage sharing processes caused by the coupled inductor are analyzed in detail. Furthermore, the design guideline of the passive snubber is discussed. Finally, the experimental study has been done on a 1500 Vdc/60 W laboratory-made prototype composed of three flyback series modules, and the feasibility of the proposed method and the theoretical analysis is verified by the experimental results.