Simultaneous Scheduling of Multiple Frequency Services in Stochastic Unit Commitment

• Published in: IEEE transactions on power systems Vol. 34; no. 5; pp. 3858 - 3868
• Main Authors: Badesa, Luis, Teng, Fei, Strbac, Goran
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Carbon; Damping; Electric power grids; Environmental impact; Frequency response; Generators; Indexes; Inertia; Mathematical model; Optimization; Power system dynamics; renewable generation uncertainty; Security; Stochastic processes; Task scheduling; Time-frequency analysis; Unit commitment
• ISSN: 0885-8950; 1558-0679
• DOI: 10.1109/TPWRS.2019.2905037

The reduced level of system inertia in low-carbon power grids increases the need for alternative frequency services. However, simultaneously optimizing the provision of these services in the scheduling process, subject to significant uncertainty, is a complex task given the challenge of linking the steady-state optimization with frequency dynamics. This paper proposes a novel frequency-constrained stochastic unit commitment model which, for the first time, co-optimizes energy production along with the provision of synchronized and synthetic inertia, enhanced frequency response, primary frequency response and a dynamically-reduced largest power infeed. The contribution of load damping is modeled through a linear inner approximation. The effectiveness of the proposed model is demonstrated through several case studies for Great Britain's 2030 power system, which highlight the synergies and conflicts among alternative frequency services, as well as the significant economic savings and carbon reduction achieved by simultaneously optimizing all these services.