Grid-forming capability of power plant control: optimization through battery energy storage integration

Integrating inverter-based resources (IBRs) is becoming crucial in transitioning to more sustainable and renewable energy sources. The increasing integration of IBRs into the power system leads to complexity and challenges regarding ancillary services, reliability, and power system operation. Hence, through grid codes, obligatory regulations have been introduced to be pursued by customers to impose control capability on IBR plants. A power plant controller (PPC) plays a vital role in managing the output of IBRs to comply with grid code requirements. Unlike traditional grid-following controllers, which rely on the presence of a stable grid and may not provide very effective ancillary services during disturbances, a grid-forming PPC can establish and maintain grid stability independently and fulfil the grid code requirements at the point of common coupling (PCC) even under weak grid conditions and during disturbances. Therefore, this paper concentrates on the innovative concept of grid-forming PPC to enhance grid stability and compliance by integrating battery energy storage systems (BESSs) in a large-scale photovoltaic (PV) power plant. Grid-forming PPC coordinates the production of individual IBR units, adjusts their output in response to grid conditions and faults, and actively contributes to grid stability by regulating voltage and frequency.