WorkingPaper, ponencias invitadas y contribuciones en congresos no publicadas http://hdl.handle.net/11531/4153 2026-06-30T12:49:45Z 2026-06-30T12:49:45Z Olasoji, Azeez O. Oyedokun, David T.O. Rajabdorri, Mohammad Sierra Aguilar, Juan Esteban Mditshwa, Mkhutazi Okafor, Chukwuemeka Emmanuel Khoza, Best Folly, Komla A. http://hdl.handle.net/11531/110938 2026-06-30T04:37:46Z

Título : Uplift Pricing for Inertia and Reserve via ML-Based Frequency-Constrained Unit Commitment Autor : Olasoji, Azeez O.; Oyedokun, David T.O.; Rajabdorri, Mohammad; Sierra Aguilar, Juan Esteban; Mditshwa, Mkhutazi; Okafor, Chukwuemeka Emmanuel; Khoza, Best; Folly, Komla A. Resumen : ; High penetration of inverter-based sources makes power systems susceptible to frequency excursions, leaving power systems short of synchronous inertia and uncompensated spinning reserve headroom. Traditional unit commitment (UC) approaches are incapable of catering to the needs of modern power systems. This paper proposes a transparent, regulator-friendly remedy that requires no real-time market redesign. A linear logistic regression surrogate, trained on 117 000 dynamic simulations, is embedded in the MILP to enforce post-fault frequency constraint. Spinning reserve headroom is remunerated through a fixed uplift tariff proportional to each generator’s marginal energy cost. Three deterministic day-ahead scenarios are compared on a real power system—La Palma (Spain): S0—reserve free; S1—tariff applied ex-post; S2—tariff co-optimised with energy. Co-optimisation (S2) increases weekly expenditure only 4.2 % relative to the cost-only baseline and is 0.2 % cheaper than the ex-post variant (S1). Fuel (operation) cost and renewable curtailment remain unchanged, depicting that the tariff does not distort the merit order. Although worst-case system inertia drops by 9 MW•s, the nadir limit binds 75 h/wk−1 versus 59 h/wk−1 in S0/S1, impeding under-frequency risk without raising RoCoF exposure. Reserve payments become less concentrated; the Gini coefficient, a measure of inequality, falls from 0.26 to 0.24, and the share captured by the three highest-earning units drops slightly to 56%. These results demonstrate that a single co-optimised uplift tariff—underpinned by an ML-based nadir constraint—thus delivers frequency security and fair cost recovery at negligible economic and operational impact, offering an immediately deployable solution for low-inertia grids.

Olasoji, Azeez O. Oyedokun, David T.O. Adeyinka, Adebayo Victor Rajabdorri, Mohammad Sierra Aguilar, Juan Esteban Ajayi-Obey, Akinola Aluko-Olokun, Pelumi Peter http://hdl.handle.net/11531/110937 2026-06-30T04:37:37Z

Título : Co-Optimizing Synthetic and Synchronous Inertia in Frequency-Constrained Unit Commitment: A Case Study on La Palma Autor : Olasoji, Azeez O.; Oyedokun, David T.O.; Adeyinka, Adebayo Victor; Rajabdorri, Mohammad; Sierra Aguilar, Juan Esteban; Ajayi-Obey, Akinola; Aluko-Olokun, Pelumi Peter Resumen : ; 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.

Álvarez Quispe, Erik Francisco Ramos Galán, Andrés http://hdl.handle.net/11531/110936 2026-06-30T04:37:30Z

Título : When Residential Tariffs Fail to Reward Flexibility: Modelling Prosumers Under Realistic Tariff Structures Autor : Álvarez Quispe, Erik Francisco; Ramos Galán, Andrés Resumen : ; Residential prosumers combining rooftop PV, stationary batteries (BESS), and vehicle-to-grid (V2G)-capable EVs require distribution tariffs that reward, rather than suppress, flexibility. This paper quantifies how the structural design of monthly peak-demand charges affects prosumer operations in Sweden. Using the EL1XR-Opt MILP framework, we co-optimise PV, battery dispatch, EV smart charging, and V2G under an explicit tariff model over a full year of hourly data across ten representative households from a low-voltage network in the SE3 bidding zone; perfect-foresight results are upper bounds on achievable cost reduction. Five tariff scenarios decompose the current Swedish effekttariff (monthly power-demand charge) into three design dimensions: charge level (μpk), selection window (daily-reset vs. monthly-pool), and averaging intensity (|K|). The peak charge reshapes rather than uniformly suppresses DER dispatch: BESS throughput remains substantial while V2G is disproportionately constrained. More strikingly, structural alternatives at the same nominal charge rate raise household costs by 33–38% and penalise inflexible households most severely, exposing a significant tariff equity risk. Halving the charge rate (μpk÷2) is the sole Pareto-favourable lever: it reduces costs by 11.2% with near-unchanged grid peak. These findings provide quantitative evidence for the tariff parameters that Swedish regulators and DSOs must calibrate before the 2027 rollout.

Ricardo Valdez, William Valdano, Manuel López Valdés, Francisco José http://hdl.handle.net/11531/110929 2026-06-29T04:55:10Z

Título : A Retrospective Study of Evolving Vehicle Architecture on Pitch and Vertical Kinematics using NHTSA Frontal Barrier Tests Autor : Ricardo Valdez, William; Valdano, Manuel; López Valdés, Francisco José Resumen : ;