Single-Stage Step-Down Power Factor Corrector without Full-Bridge Rectifier

In this paper, a single-stage step-down power factor corrector without a full-bridge rectifier is developed, which is designed to operate in discontinuous conduction mode (DCM). In terms of control, the DCM has the advantages of simple control and easy realization, no slope compensation, zero current switching, and no diode reverse current. By sampling the output voltage and using the voltage-follower control to generate the necessary control force to drive the power switch, not only can the output voltage be stabilized at the desired value, but also the input current can be, as much as possible, in the form of a sinusoidal waveform and can follow the phase of the input voltage. Moreover, the harmonic distortion meets the requirements of the IEC6100-3-2 Class D harmonics standard, and, thus, the proposed rectifier is appropriate for the computer, computer monitor, and television receiver. Eventually, by means of mathematical deductions, simulations by PSIM version 9.1, and experimental results, the feasibility and effectiveness of the proposed circuit can be verified.