Estudio técnico para planificación de mantenimiento en subestaciones eléctricas bajo criterios de confiabilidad HL-III

Abstract

This thesis presents a technical study focused on maintenance planning in a power substation, applying HL-III reliability criteria and condition-based maintenance strategies. The case study corresponds to the Centro Industrial Substation of CNEL EP – Los Ríos Business Unit, which supplies a significant residential, commercial, and industrial load. Based on historical operation and failure data, the electrical demand behavior is analyzed, and the service life of the power transformer is evaluated using thermal models in accordance with IEC 60076-7 and IEEE C57.91 standards. Two condition-based maintenance scenarios are assessed: perfect maintenance and imperfect maintenance, and their performance is compared with a base case without intervention. The results show that perfect maintenance extends the transformer service life by approximately 16.5 years, while imperfect maintenance achieves an extension of about 12.8 years. Additionally, an HL-III reliability analysis is conducted using probabilistic simulations, allowing the estimation of energy not supplied and its associated economic impact. Finally, a financial assessment is performed, demonstrating the technical and economic feasibility of the proposed substation modernization and the recommended maintenance plan. Keywords: Condition-Based Maintenance, Electrical Substation, Energy Not Supplied, Power Transformer, Reliability.