Predictive Current Control Method with State Observer for Grid-Connected Inverter Equipped with LCL-Filter

Abstract

This paper presents a predictive control strategy for a grid-connected voltage source inverter with an LCL filter. A full-state observer is used to estimate the LCL filter capacitor voltage to reduce the sensing component. The estimated capacitor voltage is used by the proposed predictive control method. The LCL filter model and converter model are used to predict the control goals. The objective function without the weighting factor is formulated to form the optimal control problem. The proposed control strategy offers an excellent steady-state and transient performance. Design steps for the state estimator and the proposed method are extensively provided. The simulation work validates the theoretical framework. The simulation results confirm that the proposed control method provides a stable grid integration and robust energy conversion process. The theoretical expectations are verified by the simulation-based case studies.