A Reconstruction-Free Model Predictive Control Method with Reduced Switching Frequency for a Four-level Single Flying Capacitor Converter

This article presents a model predictive control strategy with a finite control set (FCS-MPC) for a four-level single flying capacitor (4L-SFC) inverter. One of the key challenges in this topology is the regulation of the flying capacitor (FC) voltages. In the proposed method, the control objectives of the 4L-SFC are addressed through a finite-control-set model predictive control framework, which manages both the output current control and FC voltage balancing. In addition to its ability to control multiple objectives simultaneously, the proposed method is compared against two other advanced MPC-based strategies that incorporate reconstruction and modulation techniques-RFCS-MPC and M2PC, respectively. A major advantage of FCS-MPC is its lower computational complexity, making it more suitable for practical real-time implementation. The performance of the proposed control scheme is validated through simulation studies conducted in PSIM software, using a 4L-SFC inverter. The results confirm the method's effectiveness in terms of both steady-state accuracy and transient-state response, demonstrating its superiority in selected control scenarios.