Single stage AC-to-DC converter to comply with IEC-1000-3-2 using the delayed forward converter

A new input current shaper is proposed in this paper. The operating principle is based on the connection of an additional output of the power converter between the input rectifier and the bulk capacitor in a conventional switching-mode power supply with no power factor correction. This additional output is obtained from the converter's transformer and it is the same type of output as the output of a delayed forward converter, which has one extra inductor in comparison with a standard forward converter. With the final topology, a good trade-off between capacitor voltage, re-cycling energy and harmonic content can be established in order to comply with IEC 1000-3-2 specifications.