A novel single-phase buck PFC AC-DC converter using an active buffer

The present paper discusses a new circuit configuration and a new control method for a single-phase AC-DC converter with power factor correction (PFC) and a power pulsation decoupling function. 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 side, which allows low output voltage ripple even on a small output energy buffer at the same time using an 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 capacitor voltage variation through the active buffer. In the present paper, the fundamental operations of the proposed converter are investigated experimentally. The experimental results reveal that the input current THD is 1.44%, the rate of the output voltage ripple is 6.33%, and the input power factor (P.F.) is over 99%. In addition, a maximum efficiency of over 96% is obtained for a 750-W prototype converter.