Rapid Power Control of Grid-Connected PV System for Grid Frequency Support

The increasing integration of grid-connected photovoltaic systems (GCPVS) can potentially cause operational challenges for the power network. It is known that traditional governor controls in conventional generating units ensure primary load frequency regulation, preventing significant frequency variations during imbalances. However, the gradual displacement of conventional generators by renewable distribution generators, like PV power plants (PVPPs), challenges system inertia and frequency stability. Existing literature gaps highlight the limited focus on frequency stability amidst substantial PV integration. To address this, the study proposes a novel automatic/active power control (APC) strategy integrated into a single-stage inverter controller. The proposed control will operate in two modes: normal mode at normal frequency and disturbance mode during frequency deviations. For this purpose, an accurate detection method has been designed to transition the controller from normal to a disturbance mode for rapid and efficient APC control. The research formulates control methodologies, devises power control strategies, and presents a simplified and rapid control facet, meeting contemporary integration standards. Results demonstrate the proposed APC's effectiveness under varying frequency scenarios, providing valuable insights for future GCPVSs.