This article presents a detailed model of an AC/DC converter with capacity to correct power factor, by representing the electrical circuits on the different operation cycles. First, the differential equations and states space models are obtained, then an averaged model. Based on this model a control law is proposed to achieve a high power factor correction, what was numerically verified by using POWERSIM© toolbox of MATLAB®. The results were analyzed by following the standard IEC 61000-3-2.