
Local
Monitoring and Control Techniques
Check the circuit of the breaker failure
protection.
No Breaker failure protection or
it doesn’t work
11
Breaker failure protection trips all
the breakers at the substation
10
Send reclosing signal to the breaker
Autoreclosing fails to restore the
line
9
Autoreclosing succeeds to restore
the line
8
Check
the breaker circuit.
Circuit
breaker fails to open
7
Circuit breaker opened by a trip
signal
6
Check communication channel
Send blocking Signal if necessary
Trip signal failed to be blocked
5
Trip signal blocked by the other
device in the system
4
Check the defects in relay algorithm and
settings
Relay
detects a fault and initiates a trip signal
3
Stand
by
Relay
does not detect a fault
2
Keep
monitoring
No
fault in preset zones
1
Reference
Action
Scenarios
Node
Event Tree
Analysis (ETA)
Design a set of event trees for each of distance relay systems to monitoring relay operations
Example
Event explanation