Analysis and Design of a Novel Isolated SEPIC Converter

The high frequency of power electronics has further increased the requirements for switching devices. Compared to the common Si device-based flyback topology, the newly designed isolated SEPIC converter utilizes GaN devices to achieve high switching frequencies and uses planar transformers instead of conventional wire-wound transformers, which can reduce switching losses and improve efficiency while drastically reducing the overall magnetic size and footprint. In this paper, the new isolated SEPIC converters are designed to operate in resonant DCM mode to ensure that ZVS of the switching tubes is achieved, thus further improving efficiency.