Model predictive control of three-level bidirectional DC-DC converter based on super capacitor energy storage system

Abstract

Aimed at the problem that the switch tube of traditional two-level bidirectional DC-DC converter is under high voltage stress and has large ripple of output current. A three-level bidirectional DC-DC converter is designed to control the power flow of the super capacitor, and Model Predictive Control(MPC) method is used to control the converter. With DC-bus voltage and flying capacitor voltage as the control objectives, MPC optimizes the objectives by prediction modeling and minimizing the objective function. It has the advantages of definite control, simple implementation, and low current ripple for charge-discharge of the super capacitor. Finally, a simulation comparison is made between MPC and traditional double closed-loop control to verify validity and efficiency of the method proposed in this paper.