Grid Frequency Control Using a Connected PV System
Recently, integration of inverter-based distributed generators (DGs) and renewable energy sources (RESs) into power systems (due to energy crisis and environmental issues) is rapidly growing, which adds great challenges to the systems performance and stability. Therefore, new control strategies are essential for these systems. High penetration of the DGs/RESs decreases total inertia and damping of the conventional bulk power systems. Thus, systems become more sensitive to the fault and disturbance, and system’s stability margin is decreased. However, most of presented control methods, e.g., conventional droop control, provide barely any inertia/damping support for the grid. To cope with this problem, the concept of virtual synchronous machine/generator (VSM/VSG) has been introduced recently. Almost all the VSG-based methods are common in emulating the inertia/damping properties of conventional SG via swing equation, virtually.