Reduction of DC-link capacitance in bridgeless PFC boost rectifiers

In this paper, a low-cost bridgeless power factor correction (PFC) boost rectifier with a small DC-link capacitor is proposed, where a buck-boost converter with a low power rating is added at the DC link. To solve an inherent problem of the second-order power ripple flowing from the source to the DC side in single-phase converter system, an auxiliary circuit is utilized to absorb the power ripple, by which the DC-link capacitance can be reduced by about one-eighth. As a result, the bulky electrolytic capacitor can be replaced by a small film capacitor. In the meanwhile, the input current is regulated to be sinusoidal by the PR (proportional resonant) and repetitive control. The validity of the proposed method have been verified by simulation results.