Proposal of a timer controller with constant switching frequency and power factor correction

The proposal of this paper is to introduce a new control technique for power factor correction in ac-dc converters. It combines the advantages of conventional hysteresis control strategy and the prominent characteristics of constant switching frequency. The fundamental idea consists in determining the ideal time period that exists between the moment when the input current crosses with the reference current and the converter commutation. Thus the input current can oscillate around the reference current with constant frequency of operation. The operating principles, theoretical analysis and results on a single-phase boost converter are presented to validate the proposal.