A Universal Model Predictive Control for Practical AC Microgrids with PVs and Battery Energy Storage Systems

In the existing research of microgrids, the inputs of the distributed inverters are usually connected to dc power sources to simulate a variety of renewable energy resources. For control techniques development of inverters, it is reasonable and sufficient because this assumption can facilitate the design process. From the viewpoint of practical applications, however, the intermittent nature of such energy resources must be considered. In this work, a parallel-inverter based ac microgrid with solar photovoltaics (PVs) and battery energy storage systems (BESSs) is presented. Based on this configuration, a universal model predictive control method is proposed. The BESS system is integrated through a model predictive current control (MPCC) based bidirectional buck-boost converter, aiming to stabilize the dc-bus voltage for PV output smoothing. Furthermore, the parallel inverters are controlled by incorporating a model predictive voltage control (MPVC) scheme with droop method to ensure stable ac voltage output and proper load sharing. The microgrid configuration and the proposed control strategy are validated by Matlab/Simulink simulation.