Model Predictive Control for Master-Slave Inverters in Microgrids

This paper proposes a Master-Slave Model Predictive Control for parallel grid-tied inverters in a microgrid. In this configuration, the Master is a grid-forming inverter with a Battery Energy Storage System as dc input, while the Slave is a grid-following PV inverter that provides the power to the load. First, the inverter models are derived and then their MPC controllers are presented in details. Finally, Hardware-in-the-Loop results are presented for different operational conditions for the microgrid, including grid connection, islanded mode and load variations. The results demonstrate the advantages of the proposed MPC such as faster dynamic response, multi variable control, adequate load sharing between the inverters, robustness to parametric uncertainties and variations and the possibility to directly include system constrains and non-linearities in the controller implementation.