10th IEEE Texas Power and Energy Conference - TPEC 2026, Texas (United States of America). 08-10 February 2026
Original summary:
High penetrations of converter-interfaced renewable energy sources (RES) are eroding synchronous inertia in many power systems, making frequency security a binding constraint in unit commitment (UC), especially for weak island grids. This paper develops an analytical frequency-constrained unit commitment (FCUC) formulation that (i) co-optimises synchronous inertia and synthetic inertia (SI) from wind power plants and (ii) supports both classical DC power-flow and PTDF-based linear sensitivity factor (LSF) network representations within a unified mixed-integer linear programming (MILP) framework. The frequency nadir constraints is enforced via a separable-programming approximation that remains fully MILP-compatible. The model is validated on the real La Palma island system. Results show that, under an unconstrained network (transmission-capacity factor TCF =1.0), varying the emulated inertia constant kem between 0 s and 6 s has negligible impact on total cost, renewable spillage, and frequency-security indicators: RoCoF remains orders of magnitude below its limit and the nadir constraint is numerically binding in all cases. A comparison between DC and LSF formulations confirms that the LSF model closely reproduces the DC dispatch and frequency metrics while achieving smaller optimality gaps. A subsequent TCF evaluation shows that tightening transmission limits only becomes economically material at TCF=0.6, where costs rise and a small amount of RES curtailment appears, without compromising RoCoF or nadir security. Overall, the results demonstrate that SI from wind can be co-optimised with synchronous inertia and LSF-based transmission constraints in a single tractable FCUC model, providing a structured way to assess inertia provision, wind utilisation, and congestion management in low-inertia island grids.
English summary:
High penetrations of converter-interfaced renewable energy sources (RES) are eroding synchronous inertia in many power systems, making frequency security a binding constraint in unit commitment (UC), especially for weak island grids. This paper develops an analytical frequency-constrained unit commitment (FCUC) formulation that (i) co-optimises synchronous inertia and synthetic inertia (SI) from wind power plants and (ii) supports both classical DC power-flow and PTDF-based linear sensitivity factor (LSF) network representations within a unified mixed-integer linear programming (MILP) framework. The frequency nadir constraints is enforced via a separable-programming approximation that remains fully MILP-compatible. The model is validated on the real La Palma island system. Results show that, under an unconstrained network (transmission-capacity factor TCF =1.0), varying the emulated inertia constant kem between 0 s and 6 s has negligible impact on total cost, renewable spillage, and frequency-security indicators: RoCoF remains orders of magnitude below its limit and the nadir constraint is numerically binding in all cases. A comparison between DC and LSF formulations confirms that the LSF model closely reproduces the DC dispatch and frequency metrics while achieving smaller optimality gaps. A subsequent TCF evaluation shows that tightening transmission limits only becomes economically material at TCF=0.6, where costs rise and a small amount of RES curtailment appears, without compromising RoCoF or nadir security. Overall, the results demonstrate that SI from wind can be co-optimised with synchronous inertia and LSF-based transmission constraints in a single tractable FCUC model, providing a structured way to assess inertia provision, wind utilisation, and congestion management in low-inertia island grids.
Spanish layman's summary:
El artículo propone una herramienta para planificar la generación en redes insulares con más renovables, combinando inercia convencional y eólica para mantener segura la frecuencia con menor coste y menos vertido.
English layman's summary:
This paper proposes a tool to plan power generation in island grids with more renewables, combining conventional and wind-based inertia to keep system frequency secure while limiting costs and wind curtailment.
Keywords: Frequency-constrained unit commitment (FCUC), synthetic inertia (SI), wind power, renewable energy
DOI: 
https://doi.org/10.1109/TPEC67884.2026.11513199
Published in: 2026 IEEE Texas Power and Energy Conference (TPEC), pp: 1-6, ISBN: 979-8-3315-5721-8
Publication date: 15-May-2026.
Citation:
A.O. Olasoji, D.T.O. Oyedokun, A.V. Adeyinka, M. Rajabdorri, J.E. Sierra-Aguilar, A. Ajayi-Obey, P.P. Aluko-Olokun, "Co-Optimizing Synthetic and Synchronous Inertia in Frequency-Constrained Unit Commitment: A Case Study on La Palma", presented at 10th IEEE Texas Power and Energy Conference - TPEC 2026, Texas, United States of America, 08-10 February 2026. In: 2026 IEEE Texas Power and Energy Conference (TPEC), pp. 1-6, doi: 10.1109/TPEC67884.2026.11513199
IIT-26-195C
