267-26

Assessment of Dynamic Line Rating for Transmission Planning in the Costa Rican
Power System

P. Castillo(1), G.A. Gómez-Ramírez(2), M.T. Bedialauneta(1), I. Albizu(1)

1. Department of Electrical Engineering, University of the Basque Country UPV/EHU Campus of Gipuzkoa, Spain

2. Department of Electromechanical Engineering, Costa Rica Institute of Technology, Cartago, Costa Rica

2026-06-27

The continuous growth of electricity demand driven by electrification and the increasing penetration of renewable energy sources pose significant challenges for transmission system planning. In Costa Rica, where electricity generation is largely sourced from renewable resources, conservative planning criteria based on Static Line Rating (SLR) may lead to an underutilisation of existing transmission infrastructure. This paper evaluates the potential benefits of applying Dynamic Line Rating (DLR) to the Costa Rican transmission network using a detailed power system model implemented in ETAP. A 24-hour simulation of a representative day of peak demand is carried out, considering hourly load profiles and comparing system operation under static and dynamic thermal limits. The results show that the application of DLR significantly reduces the number and duration of thermal overloads in critical transmission corridors, particularly those connecting renewable generation areas with major demand centres. These findings indicate that DLR can increase the effective transmission capacity and defer the need for network reinforcements, providing a flexible and cost-effective alternative for transmission planning in renewables-based power systems.

Key words: Dynamic Line Rating, transmission system planning, ampacity, thermal constraints, ETAP

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