Fluctuations and Control: Understanding the Frequency of Power Grids

¹ Department of Environmental Sciences, Faculty of Science, Open University, 6419AT Heerlen, the Netherlands
² Faculty of Science and Technology, Norwegian University of Life Sciences, 1432 Ås, Norway
³ Department of Engineering Sciences, University of the Free State, Bloemfontein 9301, South Africa
⁴ Institute for Automation and Applied Informatics, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
⁵ Institute of Climate and Energy Systems: Energy Systems Engineering (ICE-1), Forschungszentrum Jülich, 52428 Jülich, Germany
⁶ Institute for Theoretical Physics, University of Cologne, 50937 Köln, Germany

Abstract

The grid frequency is the power system’s heartbeat, gauging the balance between generation and demand. In this article, we show how frequency dynamics and control can be understood in terms of a paradigmatic model of theoretical physics: the overdamped harmonic oscillator. Using frequency measurements and tools from complex systems, we can see when control steps in, why lower mechanical inertia makes modern grids more jittery, and how the “noise” in the frequency can be used as a clue for better diagnoses and smarter control — especially in renewable resources-dependent systems.