Circuit Breaker Faliure / Local Breaker Backup
50Z / 50BF / LBB / CBF Ha..! Ha..! Don't get confused upon reading the title. The explanation is just here..! This is another level of protection given for particular circuit breakers. Each power system equipment like transformer, generator, transmission line, etc. have its own protection relay which assures its smooth working and safety. When a fault occurs, one or more protection devices will operate and issue a trip command to the relevant circuit breakers. Operation of the circuit breaker is essential to isolate the fault and prevent, or at least limit, damage to the power system. For transmission and sub-transmission systems, slow fault clearance can also threaten system stability. But most of the time the circuit breaker works fine, but due to some external fault on the circuit breaker such as trip circuit lose contact, delayed circuit breaker operation, circuit breaker’s internal mechanism issue, etc. it fails to trip for the command of different relays . Here c