Power System Inertia Estimation Under Limited Frequency Monitoring Nodes

Renewable energy-driven displacement of synchronous generators leads to low system inertia which creates frequency stability issues in power system, thus necessitating system inertia estimation for secure and stable grid operation. However, one of the main challenges in system inertia estimation is frequency monitoring owing to the high cost associated with placing adequate number of measurement devices across the system. In this backdrop, a new approach for system inertia estimation with reduced number of frequency monitoring, however, without compromising estimation accuracy has been proposed in this paper. The frequency control areas depending on modal analysis based generator coherency are formed and single frequency measurement at each area determine system frequency response during grid disturbance, which in turn is used for system inertia estimation. The proposed approach of system inertia estimation has been implemented and validated on IEEE 39 bus system and Gujarat State grid developed in DIgSILENT PowerFactory simulation platform.