On-line Estimation of Power System Inertia Using Short-time Synchronous Phasor Measurements Under High Generator Damping

As intermittent renewable energy generation connected to the grid through power electronic converters is replacing conventional thermal power plants dominated by synchronous generators, the inertia of the power system is gradually decreasing. This affects the frequency response of the system, and therefore the inertia of the power system needs to be estimated to retain sufficient power reserves, assess the potential instability risk of the power system and deal with it accordingly. In this paper, an optimization method based on the swing equation is proposed to estimate the inertia of the power system using only the real-time measurements of the PMU for the purpose of online estimation. The method proposed in this paper takes into account the effect of generator damping, which has a significant impact on the power and frequency variations of the system and the inertia estimation. The classical New England 39-bus test system is used for the application of the method, where several case studies and comparisons are performed to test the accuracy and validity of the method.