Study of the 23 kV feeder protection system in coordination with the power transformer of the ANDE national interconnected system

Abstract

The objective of the work is to study the 23 kV feeder protection system in coordination with the protection system of the power transformer. An investigation of the protection system of the feeders of a determined substation of the national interconnected system of the Administración Nacional de Electricidad (ANDE) has been proposed, according to the protection philosophies and criteria of adjustments of the feeder protection equipment, according to the characteristics of the system and the role of protection equipment, in order to improve the reliability of the system. A field investigation has been carried out in the electrical protection sector of the national interconnected system and area of focus in the distribution concessionaire. The research was carried out between February 2019 and October 2020, in Asunción and the metropolitan area. Through technical visits for data collection, it has been verified that the Intelligent Electronic Devices (IEDs) used are not used to their maximum potential, being able to expand their protection capacity, making a more appropriate use of all the functions for the protection of the feeders, guaranteeing the continuity of the service. It has been proposed to adjust the IEDs as much as possible to enable the new observed functions, which complement the protection of the feeder. Finally, with the technical and financial evaluation of the project, it has been confirmed that its implementation is feasible. As recommendations, make adjustments to the IEDs of the ANDE protection system that have these new functions, and as a last resort, renew the protection relays that do not have them.