A CONTROL STRATEGY FOR A MICROGRID INTEGRATED WITH MULTIPLE SOLAR-PV UNITS AND A LARGE-SCALE BATTERY ENERGY STORAGE SYSTEM

This thesis presents a control strategy and its algorithms for a microgrid system that can operate in the grid-connected mode, in the islanded mode, and transfer between them. The microgrid includes three Solar-PV units and one large-scale Battery Energy Storage System (BESS). Performance evaluation of the microgrid is carried out in the time domain, using the PSCAD/EMTDC software platform, to demonstrate the effectiveness of the proposed control strategy. In the grid-connected mode, the three Solar-PV units are controlled to track their Maximum Power Points (MPPs) and the battery State of Charge (SOC) is maintained within a prespecified range. In the islanded mode, the BESS controls the voltage and frequency of the microgrid. The control system is also tested for other transient conditions such as load shedding, Solar-PV loss, temporary faults, reconnection to the utility grid and charge or discharge of the BESS in the case of low or high SOC, respectively.M.A.S