Small-signal modeling of a single-switch AC/DC power factor correction circuit

In this paper, a small signal model for a novel one-stage, switched-mode power factor correction (PFC) converter is presented. The model is obtained by applying the small signal perturbation technique to the circuit equations derived from the state-space averaging method. By applying the perturbation and averaging techniques over one switching cycle, the DC and small signal equivalent circuit representations of this converter are derived. The result shows that this converter exhibits the characteristics of a second order low-pass system for the output-to-input transfer function, and that of a combined second order low-pass and band-pass system for the output-to-control transfer function. The validity of the proposed mathematical model was verified by the given experimental results