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.