Protection engineers face a wide variety of device types and applications, from electromechanical to digital protection relays within conventional or even fully digital substations.
The main reasons for “incorrect operation” of protection relays can be one or a combination of:
1) Misapplication of relays,
2) Incorrect setting,
3) Personnel errors, and
4) Equipment problems or failures (relays, breakers, CTs, VTs, station battery, wiring, pilot channel, auxiliaries, and so on).
“Correct Setting” of protection relays plays an important role in the reliability of a protection system.
