Generic Low-Order Primary Frequency Response Model for Frequency Nadir Prediction

Maintaining the balance between generation and load is critical for power system frequency stability. Large disturbances disrupt this balance and cause frequency deviations from its normal operating value. Primary frequency response (PFR) occurs within the first few seconds, during which the frequency reaches its nadir before returning to a new operating point. The frequency nadir (FN) is a crucial indicator of frequency stability. Accurate FN estimation helps operators assess stability risks and determine necessary PFR resources and frequency regulation reserves. Existing analytical methods face issues such as poor applicability, inability to numerically solve for FN, and unexplored rationale for low-order fitting. This paper proposes a generic low-order PFR model applicable to different governor-turbine systems, enabling efficient numerical calculation of the frequency nadir.