Enhanced Control for Integrated Active Power Decoupling in Single-Phase Three-Level Flying Capacitor PFC Converter

This paper proposes an improved control for an integrated active power decoupling in a single-phase power factor correction flying capacitor topology. In a bridge rectifier, the distorted current is a major concern. Besides, the double-line frequency DC voltage ripple may require a bulky capacitor, resulting in extra volume. This paper presents a control strategy to use the intrinsic film flying capacitors available at the three-level power factor correction (PFC) converter to reduce the DC side voltage ripple without adding additional components, while the input current is controlled to achieve a unit PF. To mitigate the output voltage oscillations, a flying capacitor (FC) voltage control takes advantage of the FC tolerance for a higher voltage oscillation near the operational voltage. The proposed control is straightforward and has been verified through simulations. The proposed method achieved 30% DC bus ripple reduction, reducing the DC output filter capacitor and integrating the FC PFC converter with an internal active power decoupling.