Dual-Stage Control Strategy for a Flying Capacitor Converter Based on Model Predictive and Linear Controllers

• Published in: IEEE transactions on industrial informatics Vol. 18; no. 4; pp. 2203 - 2212
• Main Authors: Lezana, Pablo, Norambuena, Margarita, Aguilera, Ricardo P.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.04.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Capacitors; Control systems; Controllers; Converters; Cost function; Flying capacitor converter (FCC); linear control; model predictive control (MPC); Predictive control; Pulse duration; Pulse width modulation; Steady-state; Switches; Transient analysis
• ISSN: 1551-3203; 1941-0050
• DOI: 10.1109/TII.2021.3096947

This article proposes a novel dual-stage control strategy for a flying capacitor converter. During transients, the proposed control scheme applies finite-control-set model predictive control to drive the system close to the desired reference, including all the known nonlinearities of the system in the converter model. When the converter state is in a neighborhood of the reference, the dual-stage controller switches to a pulsewidth modulation based linear controller with an integral action. In this case, the linear controller is reformulated in its feedback form. Thus, the internal linear controller states can be updated based on the actual input applied by the predictive controller. This allows the dual-stage controller to achieve a smooth transition when commuting between controllers and a zero-steady-state error even when load parameter errors are present. Experimental results are provided to verify the effectiveness of the proposed dual-stage controller.