Integrated Boost and Dual-Switch Forward Converters as Soft-Switching Single-Stage PFC Converter

In this article, a new isolated single-stage soft-switching power factor correction (PFC) circuit is proposed. In this structure, the boost PFC is merged with the dual-switch forward dc–dc converter. Both the PFC and dc–dc sections are operated in the DCM condition, allowing the voltage of the bulk capacitor to be nearly independent of the output power level. The achieved soft switching condition as well as recovering leakage inductance energy resulted in high efficiency. The experimental results justify that the grid current is in accordance with the IEC 61000-3-2 Class D standard. A laboratory prototype is evaluated to validate the theoretical analysis and operational principles. The provided experimental results demonstrate low total harmonic distortion while achieving high efficiency.