Multifunctional Control of Grid-Connected Converters with Model Predictive Control and Disturbance Observer

This article presents a multifunctional control system for grid-connected converters with LCL filters that combines indirect model predictive control (MPC) with a disturbance observer and feedback correction. The proposed strategy enables operation in both grid-forming and grid-following modes, with seamless transitions between them. To protect the converter from overcurrents, the converter current is limited in two stages: first via a current-limiting structure integrated into the observer, and second through explicit current constraints within the MPC optimization problem. The presented results demonstrate excellent reference tracking, mode transition, and fault ride-through capability. The proposed method is compared with an observer-based control system, highlighting the advantages of the MPC-based approach.