ANN-based Cooperative Frequency Restoration in a Network of Grid-forming and Grid-following Inverters

An artificial neural network (ANN) inspired cooperative hierarchical control scheme for frequency restoration during sudden source/load variations in a network of grid-forming and grid-following inverter-based resources (IBRs) is proposed. The photovoltaic (PV) sources’ regulated power harvesting ability is leveraged for immediate frequency support in response to potential disturbances. The ANN-inspired supervisory controller (SC) estimates the demanded power (ΔP) to regulate the frequency which is then optimally distributed amongst all PV interfaced IBRs by a Power Allocator (PA) module; located in the secondary layer cluster coordinator (CC). The PA module ensures that the interfaced PV’s generation limits are not violated while also minimizing system losses. Detailed description of each module in the cluster along with their technical specifications are provided. Finally, simulation results that justify the feasibility and robustness of the proposed control scheme to restore the grid frequency in a timely manner are discussed.