Increasing Efficiency and Power Factor for Power Supplies Using Parallel Flyback Converter

Increasing of ac/dc power supply, losses, and harmonic problems arise and power factor decrease due to the presence of the converter. Therefore, a fast, accurate and high-power supply performance became mandatory. In this paper, a new topology of dual flyback converters operated in parallel is introduced to increase the power factor, decrease the total current harmonic distortion and reduce the losses. The first flyback converter is utilized as dc/dc stage used to regulate the output voltage by adjusting the duty cycle. While the second flyback converter is utilized as ac/dc stage, it is also used for the power factor correction and reducing the harmonics. The second flyback converter generates the input current to be in phase with the input voltage by regulating the variable frequency and switching period keeping the switching on-time fixed. This topology improves the voltage regulation even if the input voltage is reduced by approximately 60%, small circuit size, improving power factor, reducing the total harmonic distortion, and increased efficiency. Finally, a small-scale prototype platform that has the ability to deal with universal input 80-260 V-rms, enhancing the supply performance, is carried out. The measurements have verified the theoretical analysis to check the effectiveness of the proposed system.