Time-Overcurrent Relay Coordination: A Review

When two protective apparatus installed in series have characteristics, which provide a specified operating sequence, they are said to be coordinated or selective. The coordination of directional overcurrent relays poses serious problems in the modern complex power system networks, which are interconnected. Researchers have looked upon the problem of coordination from different considerations by making use of computer aids. Many efforts have been made to the automation of the coordination process in the area of relay coordination. This paper compiles the most of the significant developments in the area of time-overcurrent relay coordination using different techniques and methodologies. It is hoped that this work will be useful for future generation researchers to find the relevant references to advance the research work in future.