A parallel-connected single phase power factor correction approach with improved efficiency

In this paper, a new parallel-connected single phase power factor correction (PFC) topology using two flyback converters is proposed to improve the output voltage regulation with simultaneous input power factor correction and control. This approach offers lower cost and higher efficiency by parallel processing of the total power. Flyback converter-I primarily regulates output voltage with fast dynamic response and processes 55% of the power. Flyback converter-II with ac/dc PFC stage regulates input current shaping and PFC, and processes the remaining 45% of the power. This paper presents a design example and circuit analysis for 200 W power supply. A parallel-connected interleaved structure offers smaller passive components, less losses even in continuous conduction inductor current mode, and reduced volt-ampere rating of dc/dc stage converter. TI-DSP, TMS320LF2407, is used for implementation. Simulation and experimental results show the performance improvement.