High-Performance Single-Stage Universal-Input Isolated AC-DC Converter Utilizing an Impedance Control Network

This paper introduces a single-stage universal-input isolated ac-dc converter based on the impedance control network (ICN) architecture. This single-stage converter can perform power factor correction (PFC) and output voltage regulation, while maintaining high efficiency over its entire range of ac input voltage and output power. By using appropriate inverter and rectifier phase-shift control strategies, this converter achieves soft-switching of all inverter transistors with minimal circulating current, throughout the line cycle. The ICN converter also allows all its inductors to be integrated and realized in a single magnetic structure, reducing the number of magnetic components in this converter to two. A design methodology for ICN-based ac-dc converters is also introduced. A universal-input, 20-V output, 400-kHz GaN-based prototype ICN-based ac-dc converter, designed for a maximum output power of 330 W, is built, and tested. The prototype achieves a full-power efficiency of 92%. This paper is the first reported work on the architecture, design, and control of ICN-based ac-dc converters.