A Straightforward Methodology to Modeling High Power Factor AC–DC Converters

In this paper, a straightforward methodology to modeling high power factor (HPF) ac–dc converters is presented. The proposed methodology is based on the averaging technique directly applied to the converter under modeling. An averaged large-signal equivalent circuit is thus generated, which is useful to perform extremely fast simulations. From the large-signal model, both a steady-state and a small-signal analysis can be carried out to completely model the converter, achieving any desired steady-state characteristic and small-signal transfer function. The presented methodology is very intuitive and allows designers to achieve a natural understanding of the converter behavior. The methodology is illustrated with a HPF buck–boost converter operating in discontinuous conduction mode. Simulation and experimental results are provided to validate the proposed methodology.