A discrete modeling for power factor correction circuit

In this paper, a novel discrete model has been proposed to simulate the controller IC UC3854. The main contributions are as followings: 1) The power stage of the Boost converter has been modeled by using the large signal approach and the loop gain of current program has been put forward; 2) The continues-time voltage control diagram has been investigated by employing equivalent power stage which contains the main circuit and current program; 3) Based on the continues-time model, a new discrete model of PFC has been given out and the operational principle has been introduced; 4) A 4kw prototype has been built up to verify the validity of the new model; Results of the simulation and the experiment show that the power factor is 96.7% and the linear current harmonics components can completely meet the requirements of IEC 61000-3-2.