Isolated single-stage high power factor AC/DC converter

The problem of harmonic pollution has brought wide attention with the increase of power customers. Adoption of the technology of active power factor correction (APFC) with advanced high frequency power converter is a more efficient solution to the problem of harmonic pollution. A single-stage isolated high power factor AC/DC converter, which features a wide range of DC output, high power factor, lower harmonic pollution in input current, and phase-shift PWM full-bride circuit, can achieve soft switching. The principle of circuit topology and the reasons of voltage surges across the power switch are analyzed. Experiment results illustrate that this circuit has the advantages of higher power factor and lower harmonic distortion.