Interleaving Control Schemes for Critical-Mode Boost PFC

Interleaving control schemes are widely used in converter applications. Merits of such control methods are to reduce the input/output current or voltage ripples and volume, and to increase the processed power capacity of converters. For converters with constant operation frequency, it is easy to achieve interleaving control. However, it is difficult to realize interleaving features with variable operation frequency, such as boost-type power factor correctors (PFCs) operated in critical-mode (CM) condition. This paper proposes several interleaving controllers for CM boost PFCs. Analysis and design of the interleaving controllers are first described in detail. Moreover, simulated results of CM boost PFCs with two-phase and four-phase interleaving controllers are introduced. Finally, experimental results of a two-phase interleaved CM boost PFC are presented to verify the discussed features.