Modular System of Cascaded Converters Based on Model Predictive Control

A modular system of cascaded converters based on model predictive control is proposed to meet the application requirements of large capacity and high voltage in renewable energy power generation systems. The system takes the CLLLC + Buck/Boost cascade converter as a sub-module, and the input and output sides are combined in series and parallel to form a DC transformer system to realize DC voltage transformation, bidirectional energy flow, and galvanic isolation. The CLLLC converter in the sub-module works in the DC transformer mode, and Buck/Boost converter participates in voltage regulation. In this paper, the mathematical model of the system is established, the parameters are designed, the model predictive control strategy is used to control the system, and simulation analysis and experimental verification are carried out. The simulation and physical experiment results show that the model predictive control method is feasible and effective.