These relays are commonly applied to detect faults on transmission lines. A comparison of the measured impedance with the line impedance provides an indication whether the fault is in the protected zone of the relay or not. This type of relay is also assigned a device number of 21.
Which is the main relay for protecting long transmission line?
Distance relays: Power swings are more common in long transmission lines because of load variations. The relay which is less affected due to power swings is selected for the protection of long transmission lines. Mho relay is less affected due to power swings and also less affected due to load encroachment.
Which of the following relay is used on long transmission line?
Answer. 9. Which of the following relay is used for phase fault protection of long transmission lines ? (a) Reactance relay.
Which relay is used for long distance?
This type of relay is used for backup protection, fault protection, phase protection, and main protection of transmission and distribution lines. The distance relay diagram is shown below. The design of the distance relay is a simple over overcurrent relay.
Which relay is used for Mho relay?
Reactance relay is suitable for the protection of the short transmission line because its operation is independent of arc resistance. Impedance relay is suitable for medium transmission lines.