Analysis and Design of a Push-Pull Quasi-Resonant Boost Power Factor Corrector

This paper proposes a novel power-factor corrector (PFC), which is mainly composed of two-phase transition-mode (TM) boost-type power-factor correctors (PFCs) and a coupled inductor. By integrating two boost inductors into one magnetic core, not only the circuit volume is reduced, but also the operating frequency of the core is double of the switching frequency. Comparing with single-phase TM boost PFC, both the input and output current ripples of the proposed PFC can be reduced if the equivalent inductance of the coupled inductor equals the inductance of single-phase TM boost PFC. Therefore, both the power-factor value and the power density are increased. The proposed topology is capable of sharing the input current and output current equally. A cut-in-half duty cycle can reduce the conduction losses of the switches and both the turns and diameters of the inductor windings. The advantages of a TM boost PFC, such as quasi-resonant (QR) valley switching on the switch and zero-current switching (ZCS) of the output diode, are maintained to improve the overall conversion efficiency. Detailed analysis and design procedures of the proposed topology are given. Simulations and experiments are conducted on a prototype with a universal line voltage, a 380-V output dc voltage and a 200-W output power to verify its feasibility.