A New Control Method for Power Conversion in Single-Phase Buck PFC AC–DC Converters

This paper discusses a new control method for a single-phase ac–dc converter with power factor (P.F.) correction. The proposed converter can achieve low total harmonic distortion (THD) on the input current and the power pulsation decoupling function between the input and output sides, which allows low output voltage ripple even on a small output energy buffer at the same time using a new control method in active buffer. Therefore, the proposed converter does not require large smoothing capacitors or large smoothing inductors. The buffering energy is stored by a small capacitor, which controls the variation of the capacitor voltage through the active buffer. In this paper, the fundamental of the proposed control method are simulated. The simulation results reveal that the input current THD is ۲%, the rate of the output voltage ripple is ۵%, and the input P.F. is over ۹۹%. In addition, a maximum efficiency of over ۹۵% is obtained for a ۱kW prototype converter.