IEEE Power & Energy Society International Meeting - IEEE PES IM 2026, Hong Kong (China). 18-21 January 2026
Summary:
This paper addresses the problem of optimal feeder selection in underfrequency load shedding (UFLS) schemes. Conventional UFLS schemes, which remain the predominant approach in power systems, operate in predefined steps, with each step intended to disconnect a specific percentage of the total load. However, the increasing variability in load profiles, driven largely by the growing penetration of distributed generation, makes
it increasingly challenging to consistently achieve the targeted shedding levels. To overcome these challenges, we formulate the feeder selection task as a mixed-integer linear programming (MILP) problem, enabling the optimal assignment of feeders to each UFLS stage. Given the computational burden of the full MILP model, especially in large-scale systems with multiple stages and many feeders, we propose a sequential optimization
approach that solves each UFLS step independently. Both models are tested using real historical hourly data from a region in Spain. Results show that the sequential model achieves nearly the same solution quality as the full MILP formulation, with significantly lower computational effort, making it suitable for practical deployment in operational settings.
Spanish layman's summary:
Este trabajo formula la selección óptima de alimentadores en esquemas de deslastre por frecuencia como un problema MILP. Se propone un modelo secuencial que logra resultados casi óptimos con menor coste computacional, mejorando la fiabilidad y aplicabilidad del UFLS.
English layman's summary:
This paper formulates feeder selection in underfrequency load shedding as a MILP optimization. A sequential model is proposed that achieves near-optimal performance with far lower computational cost, improving the reliability and practicality of UFLS operation.
Keywords: Optimal feeder selection, mixed integer linear programming, underfrequency load shedding
DOI: 
https://doi.org/10.1109/PESIM67009.2026.11438885
Published in: IEEE PES IM 2026: Conference proceedings, pp: 1-5, ISBN: 979-8-3315-6646-3
Publication date: 23-Mar-2026.
Citation:
O. Arenas, M. Rajabdorri, L. Sigrist, E. Lobato, L. Rouco, V. Sordo, A. Santamaría, J. Gutiérrez, "Optimizing Feeder Selection Across Underfrequency Load Shedding Scheme Steps", presented at IEEE Power & Energy Society International Meeting - IEEE PES IM 2026, Hong Kong, China, 18-21 January 2026. In: IEEE PES IM 2026: Conference proceedings, pp. 1-5, doi: 10.1109/PESIM67009.2026.11438885
IIT-26-004C
