Estudio de estabilidad de voltaje en redes de transmisión de la Zona Costa Norte del SNI del Ecuador

Abstract

The stability of an electrical system is crucial to ensure reliable and safe operation of the electrical grid, especially in critical areas such as the northern coastal zone of the National Interconnected System (SNI) of Ecuador. This concept refers to the system's ability to return to an equilibrium state after being subjected to a transient disturbance, such as short circuits, the disconnection of transmission lines or significant fluctuations in load demand. To address the critical need for stability in this region, a project was carried out using DIgSILENT PowerFactory. The project began with a contingency analysis that made it possible to identify points of vulnerability, highlighting the bars B_Esmeraldas_AA1_13.8 and B_Esmeraldas_AA2_13.8 as particularly susceptible to disturbances. Following this identification, a more in-depth evaluation was carried out by constructing PV and QV curves for these critical buses, allowing the evaluation of the voltage response to load increases and the capacity of the generators to handle the reactive power necessary to maintain the stability of voltage versus load variations. Initially, it had been contemplated to make a comparison between the results obtained with DIgSILENT PowerFactory and ETAP to validate and enrich the analysis. However, the university did not have the ETAP software license, which led to the decision not to perform the comparison and to concentrate the simulation efforts exclusively on DIgSILENT PowerFactory. The results obtained are fundamental for the development of strategies that strengthen the voltage stability and the system's responsiveness to dynamic loads. These analyzes will make it possible to formulate recommendations for the implementation of corrective and preventive measures, such as the installation of reactive compensation equipment, improvements in transmission infrastructure, and the application of advanced load management programs, marking an essential step towards improving the robustness and reliability of the electricity supply in this critical area of the Ecuadorian energy system.