Simultaneous Estimation of the Time of Disturbance and Inertia in Power Systems

Offnominal power system frequency regimes play a key role in the propagation of disturbed system conditions and blackouts. The evolution of power systems will make the availability of frequency-control services more uncertain, increasing the risk of large frequency deviations. Furthermore, the reduction in the inherent inertia of power systems and their increased variability will be a critical threat to the quality of frequency control. This paper proposes an online algorithm for estimating the time of disturbance and inertia after a disturbance. This is in contrast to previous inertia estimation methods that operated offline. The algorithm processes wide-area measurements of frequency and active power and could provide support for adaptive frequency control. Simulations, laboratory tests, and real transmission system measurements have been used to demonstrate the algorithm's ability to correctly detect a disturbance, accurately estimate the time of the disturbance and the inertia, and prevent false disturbance detections.