Today's time-domain and traveling-wave protective relays operate in 1 to 2 ms. about an order of magnitude faster than their predecessors. Characteristics of sources, CT saturation, and series compensation have little or no impact on the security. The loadability limits and requirements on transmission lines can introduce additional constraints for protective relaying, as protection must be able to allow the transmission line to be temporarily overloaded while still retaining the ability to correctly detect and clear faults. Ideally, we want a protection element to respond. Transmission Line Protection Definition: Transmission line protection is a set of strategies used to detect and isolate faults on power lines, ensuring system stability and reducing damage. This is referred to as relay coordination.
[PDF Version]