Open database analysis of scaling and spatio-temporal properties of power grid frequencies

Abstract

The electrical energy system has attracted much attention from an increasingly diverse research community. Many theoretical predictions have been made, from scaling laws of fluctuations to propagation velocities of disturbances. However, to validate any theory, empirical data from large-scale power systems are necessary but are rarely shared openly. Here, we analyse an open database of measurements of electric power grid frequencies across 17 locations in 12 synchronous areas on three continents. The power grid frequency is of particular interest, as it indicates the balance of supply and demand and carries information on deterministic, stochastic, and control influences. We perform a broad analysis of the recorded data, compare different synchronous areas and validate a previously conjectured scaling law. Furthermore, we show how fluctuations change from local independent oscillations to a homogeneous bulk behaviour. Overall, the presented open database and analyses constitute a step towards more shared, collaborative energy research.

Revealing drivers and risks for power grid frequency stability with explainable AI

“…Regional differences in the grid frequency within a synchronous area are small during normal operation and are typically damped out after several seconds. 34 , 35 Although we used local grid frequency measurements, the above indicators characterize frequency stability in an entire synchronous area.

Figure 1 Overview of our explainable ML model From right to left: using publicly available external features from the ENTSO-E transparency platform, 36 such as load ramps or generation ramps, a gradient tree boosting ML model was constructed to predict indicators of frequency stability.

…”

“…Over the last few years, comprehensive datasets have become publicly available, enabling an empirical analysis of power system frequency stability. 13 , 35 Most data-driven studies focus on the impact of a single isolated feature and resort to a linear correlation analysis. For instance, studies have quantified the correlations between different measures of frequency quality and the load value and ramps in the Nordic grid, 11 wind power generation in the Irish grid, 9 load ramps in the British grid, 10 and societal events coinciding with large frequency deviations.…”

Initial analysis of the impact of the Ukrainian power grid synchronization with Continental Europe

“…Even when evaluating only four weeks, we note that the PDF of the increments for τ = 1 s is not fully Gaussian but large increments are observed more frequently. 11 Differences between the two periods are again very small. We might speculate that the values at the tails, i.e.…”

“…It is found that this bulk mode explains already above 99% of the observed variance indicated by the eigenvalue f 1 , consistent with earlier results. 11 The second component v 2 ( x ) features opposite signs in the Western and Eastern part of the grid, i.e. the frequency in the two parts always move in opposition.…”

“…9 Transient violations of perfect synchronization can occur after local disturbances, 10 but perturbations are rapidly damped out. 11 In contrast, a full loss of synchrony can have fatal consequences. For instance, the Continental European power grid split into three mutually asynchronous fragments during the 2006 European power outage after a cascade of transmission line failures.…”