Single-Phase Hybrid Switched-Capacitor PFC Boost Rectifier With Low Voltage Gain

Power factor correction (PFC) rectifiers based on the classic boost topology have become widespread owing to their current input features, and can obtain optimal results in terms of power quality. However, several applications require an output dc voltage lower than the ac input voltage. In such cases, two-stage topologies provide lower voltage values at the output, which increases the number of components. Moreover, such topologies tend to incur higher losses and are costly. Therefore, a unidirectional hybrid single-stage single-phase PFC boost rectifier with a switched-capacitor cell and low voltage gain is proposed. Furthermore, the proposed topology has two active switches, and natural balance exists between the voltages of the capacitors. Therefore, an additional control system is not required. The proposed topology was theoretically analyzed and experimentally validated using a 1 kW prototype with two different operational situations: (A) 127 V ac and 100 Vdc; (B) 220 Vac and 200 Vdc, input and output voltages, respectively. The experimental results essentially reveal that the power factor is approximately one, and the total harmonic distortion of the input current is 4.6%. The maximum efficiency achieved was 96.5% in the operational situation (B).