Modified SEPIC Converter with High Voltage Gain and ZVS Characteristics

With the increase in demand for high voltage gain characteristics, traditional Boost circuit is no longer suitable because of the extreme duty ratio. In this paper, with the integration of two diodes, three capacitors, and a transformer, a 1 MHz transformer based modified SEPIC circuit is presented. Planer magnetic components are adopted, and therefore the core volume does not increase. Higher voltage gain and lower voltage stress are obtained simultaneously. Moreover, zero voltage switching (ZVS) is achieved at the same time, which reduces the switching loss caused by the increment of switching frequency. The operational principle and parameter design process are introduced in detail. An 80 W prototype is designed to demonstrate theoretical analysis. Obtained efficiency was up to 92.6% at full load.