Dual-Mode Stable Performance Phase-Shifted Full-Bridge Converter for Wide-Input and Medium-Power Applications

Power converters with an extended range of line voltage are the main requirement in today's industrial applications such as photovoltaics- and supercapacitors-based energy systems. The variation in the line voltage severely degrades the performance of power converters, because of the extended freewheeling interval, more circulation current, narrow range of zero voltage switching, and increased EMI. This article suggests a modified phase-shifted full-bridge converter that cuts the freewheeling interval and minimizes these problems. It extends the input voltage range by keeping the operational duty cycle of the converter high over the wide range of input voltage while maintaining the performance stable. The proposed converter consists of four low-profile transformers having reconfigurable interconnection structure. There are two distinct reconfigurable modes, a series mode and a parallel mode, which can be configured with changes in the operational conditions. The operation of the proposed converter with high switching frequency improves the power density. Additionally, the use of multiple transformers minimizes the heat management efforts and reduces the overall volume of the converter. The proposed work, in this article, is validated in hardware characterization for a wide range of input voltage 100-400V(dc) and up to the load power of 1kW. The measured energy efficiency of the proposed converter remains stable over the complete range input voltage 100-400V(dc).