Model Predictive Control for an Integrated Power-Pulsation Buffer Four-Cell Flying-Capacitor PFC Converter

Single-phase power factor correction (PFC) front-ends must buffer a twice-line-frequency power pulsation, which is typically handled with bulky electrolytic DC-link capacitors or by adding decoupling components for active buffering. This article integrates the power-pulsation buffer (PPB) into the existing flying-capacitor stack of a totem-pole four-cell flying-capacitor (TP-4CFC) rectifier, eliminating auxiliary PPB hardware and reducing dependence on large, lifetime-limited electrolytic capacitors. Control is realized by a lexicographic multiobjective model predictive strategy that requires no weight tuning and is implemented for fast execution on a dual-core microcontroller with a 6.66 μs sampling period. The proposed flying-capacitor voltage-reference generation method maintains current-tracking performance while increasing the usable energy-buffering capability of the existing converter. A 2.5 kW, 400 V experimental prototype validates the approach over a wide operating range, demonstrating up to 54% reduction in DC-link ripple, 3.7% grid-current total harmonic distortion (THD), and half-cycle settling for rated load-step disturbances. Whereas auxiliary active PPB stages often reduce efficiency, the proposed approach yields a modest efficiency gain over standard operation, corroborated by a loss-and-stress analysis. The results indicate a practical path to higher power density for compact single-phase front-end rectifier applications.