An Impedance Control Network based Single-Stage Universal-Input Isolated AC-DC Converter Utilizing Reconfigurable Inverters

This paper presents a high-power-density single-stage isolated resonant ac-dc converter based on the impedance control network (ICN) with reconfigurable inverters. The ICN converter with phase-shift control can perform power factor correction and output voltage regulation while maintaining zero voltage switching (ZVS) and near zero current switching (ZCS) of its inverter transistors across a wide range of input voltage and output power. The proposed reconfigurable-inverter design allows the inverters of this converter to operate in parallel at low line and in a stacked fashion at high line, which further enhances performance by simultaneously reducing the peak inverter transistor voltage stress, the resonant inductance requirement and the transformer turns ratio by a factor of two. A 330-W, universal-input-to-20V output reconfigurable-inverter based ICN ac-dc converter prototype is designed, built, and tested. This GaN-based prototype achieves a power density of 44.5 W/in
³
and peak efficiencies of 94% and 93.8% at low-line (120 V
rms
, 60 Hz) and high-line input (230 V
rms
, 50 Hz), respectively.