A two-switch buck-boost PFC rectifier with automatic AC power decoupling capability

In this paper, a single-stage power-factor-correction (PFC) rectifier with active power decoupling function is proposed. The proposed rectifier has a low component count as compared to existing solutions. Only two active switches, one inductor and one small power-buffering capacitor are needed. High power factor, wide output voltage range and active power decoupling can be simultaneously obtained. In addition, the rectifier has an inherent automatic power decoupling capability, and no dedicated active power decoupling control is required. Therefore, the control of the rectifier is simple and easy to implement. A 100 W prototype of the proposed rectifier with 110 Vrms/50 Hz input and a regulated DC output voltage ranging from 30 V to 100 V has been constructed and tested. The results show that with only a 15 μF power-buffering capacitor, a power factor of over 0.98, peak efficiency of 93.9% and output voltage ripple of less than 3% has been achieved.