Multi-mode controlled push-pull boost power factor corrector

This paper proposes a novel multi-mode controlled power factor corrector (PFC) based on the push-pull boost PFC topology which features distributing the input and output currents equally in the internal two-phase modules, coupling the two-phase boost inductors into the same magnetic core to allow the reduction of both the circuit volume and the input current ripple under the same inductance, and a cut-in-half duty cycle to allow the reduction of switch conduction losses and the number of inductor winding turns. A multi-mode operation is further propose to integrate the discontinuous-conduction-mode single-phase operation at light loads with the switching frequency being constant over a half line cycle and proportional to the output current, the quasi-resonant mode at medium-to-heavy loads, and the continuous-conduction mode at heavy loads to improve the power conversion efficiency over the entire load range.