Estudo de proteção de transformador em uma subestação de 69 kV: parametrização e simulação de aferição do relé de proteção.

Abstract

The present undergraduate thesis aims to conduct a comprehensive study on transformer protection in a 69 kV substation, focusing on the parametrization and simulation of the protection relay. In the initial phase, a detailed bibliographic review is conducted on the elements of a substation and the most relevant ANSI protection functions, including overcurrent (50/51), undervoltage (27), overvoltage (59), and differential (87) functions. This theoretical foundation provides a deep understanding of the principles and criteria of protection employed in power electrical systems. Subsequently, the necessary calculations are carried out for the sizing of the mentioned protection functions, taking into account the specific characteristics of the transformer and the operating conditions of the substation. The calculations include the determination of current and time settings for the overcurrent functions, as well as the trip values for undervoltage and overvoltage functions. After defining the sized settings, the protection relay is parametrized, configuring it according to the calculated values for each protection function. This process involves programming the relay parameters, ensuring its ability to detect and respond appropriately to abnormal operating conditions. Finally, the protection relay calibration is simulated using a hexaphase test set. This step allows verifying the effectiveness and accuracy of the parametrized settings, ensuring that the relay can operate reliably and selectively in case of fault or overload situations. In summary, this work provides a comprehensive approach to the study and implementation of transformer protection in a 69 kV substation, demonstrating the importance of proper parametrization of protection relays to ensure the safety and reliability of the electrical system.