AJUSTE Y COORDINACIÓN DE PROTECCIONES DE DISTANCIA Y SOBRECORRIENTE PARA LÍNEAS DE TRANSMISIÓN QUE COMPARTEN EL MISMO DERECHO DE VÍA

Abstract

Transmission lines are spread over very big geographical areas and due to this; they are more exposed to risks that could lead to failures. Therefore it is not a surprise that transmission lines have the highest failure rate among all elements of electric power systems. Transmission systems can have different configurations. One common configuration is parallel lines sharing same right of way with same or different circuits and this is motivated due to the increment on power demand. Power systems become more complex and robust by applying this line configuration. In such a complex power system, daily operation causes constant reconfiguration of the system and thus there is a need to continually update the protection relays settings to avoid incorrect operations in case of fault incidence. In double circuit transmission lines sharing the same right of way and considering magnetic coupling it is very common distance relays face overreach or underreach problems in case of single line to ground faults leading thus to incorrect operations. A similar situation takes place on directional overcurrent relays since magnetic coupling causes undesired tripping. Due to this scenario in which distance and overcurrent relays might not operate correctly in non-pilot transmission lines that are magnetically coupled, there is a need to provide a methodology to overcome these problems. In this thesis a study of protection schemes operating in transmission lines with mutual coupling and considering different topologies is carried out. The topologies considered include: transmission line with common buses at both ends, transmission line with common bus in only one end and transmission line with no common buses. A methodology to adjust the settings of distance relays and overcurrent relays for the case of faults involving ground is proposed. This methodology is useful for cases where relays are set to protect parallel lines sharing the same right of way with mutual coupling effect and without communication channel. This analysis was done on a digital simulation program ASPEN OneLiner V10.12 to perform fault simulation scenarios and to test the proposed methodology on the power systems used as examples. The results obtained from those studies show a reasonable performance of protection relays operating in transmission lines with mutual coupling