A REPRESENTATIVE DISCRETE-TIME MODEL FOR UNCOVERING SLOW AND FAST SCALE INSTABILITIES IN BOOST POWER FACTOR CORRECTION AC-DC PRE-REGULATORS

Boost Power Factor Correction (PFC) AC-DC converter under fixed frequency average current control is a nonlinear and nonautonomous dynamical system characterized by two different forcing periods and thus by two different scales of time. Four different kinds of standard instability phenomena are possible for this system, depending on the parameters of the circuit. A combination of more than one instability phenomenon can also take place. In this paper, we carry out a careful and an accurate modeling of the system. First, we put into evidence most of the nonlinear behaviors that could occur in the system by using the switched circuit-based model and then we derive a unified representative discrete-time model that is able to predict accurately all these behaviors.