Adaptive Power Reserve Control for Photovoltaic Power Plants Based on Local Inertia in Low-Inertia Power Systems

Retirement of thermal power plants and growth in the capacity of power electronics-based renewable energy sources reduce the inertia of power systems, making them more sensitive to frequency disturbances. The shortfall of system inertia cannot be compensated by the remaining synchronous generators and alternative solutions are required. Photovoltaic power plants (PVPPs) can provide frequency support services through the application of flexible power point tracking methods and power reserves. This article proposes a power reserve distribution method based on local inertia across the PVPPs of a power system aimed at enhancing the system frequency response compared to fixed power reserve levels, especially in weaker and less meshed networks. A multilevel adaptive power reserve control for different system inertia levels is also proposed. The performance of the methods against different frequency events is validated through extensive real-time simulations based on benchmark network models.