A PFC Scheme for the Inverse Watkins Johnson Converter for Polarity Reversible Buck Boost DC Output Voltage

Abstract

A power factor correction (PFC) scheme for the Inverse Watkins Johnson Converter (IWJC) drawing power from a single-phase AC source, delivering polarity reversible DC voltage output is presented in this paper. The IWJC is basically a DC-to-DC converter which can deliver a boosted positive output voltage or a negative output voltage with buck or boost feature. It is suitable for driving DC loads, typically, DC motors in forward or reverse direction. Unlike the conventional four quadrant DC chopper, the IWJC can boost the input voltage and deliver a voltage higher than the source voltage with duty cycle controlled polarity reversible feature. This paper presents the methodology of including a PFC strategy for the IWJC, when fed from a single-phase AC supply. The proposed methodology has established that the AC source side power factor is unity and that the source current is maintained sinusoidal. Simulations and experimental verifications validate the proposed idea.