High Efficiency High-frequency-link Single-stage AC-DC Converter

A high efficiency single-stage isolated ac-dc converter topology is proposed in this paper. The proposed converter provides soft-switching, power factor correction (PFC), and output voltage regulation over a wide operating range in a single power conversion stage. The converter structure includes an integrated flyback snubber circuit to address the device overvoltage issues commonly observed in the isolated singlestage ac-dc PFC converters. This flyback circuit regenerates the snubber capacitor energy, thus helps in extending the converter's overall efficiency. This paper also discusses a design guideline for the proposed converter. The converter performance is evaluated in a SiC MOSFET based 1.5 kW prototype.