A new method for active power factor correction using a dual-purpose inverter in a flyback converter

In this paper, a new active method for power factor correction (PFC) is presented and applied to a single stage AC/DC flyback converter to reduce the total harmonic distortion of the input current, achieve better power factor compensation, and improve converter reliability. The proposed circuit consists of a low-power portable dual-purpose inverter that can work in 2 main modes. In the normal mode of converter operation, the PFC circuit operates as an active harmonic filter compensator. In the second mode, which occurs in converter outage conditions, the inverter behaves as a sinusoidal backup voltage power supply for the converter by using a backup battery and the SPWM control method. In this technique, the main switch of the converter operates in borderline conduction mode, but the RMS input current as well as peak and ripple currents are reduced significantly. Simulation analysis and experimental results are presented.