Direction Reversal From Sequential Clearing Of Parallel Lines - GE MiCOM P40 Agile Technical Manual

P44x/EN AP/Hb6
(AP) 5-32
Weak
Source
Weak
Source
Figure 11: Direction reversal from sequential clearing of parallel lines
The P44x provides protection against the effects of this phenomenon by employing transient
blocking. An adjustable timer is available that will block direct and permissive transfer trip
signals from being used in the P44x logic, and will also block the P44x from sending direct or
permissive transfer trip signals. This timer is designated as "Reverse Guard Timer".
This provides protection against fault current reversal and will still allow fast tripping in the
event of faults occurring in zone 1, if zone 1 is independent (not used as overreach zone).
Reverse
3
3
1
Forward
1
Relay 3 senses reverse current
3
Forward
3
1
1
Relay 3 senses forward current
MiCOM P40 Agile P442, P444
Forward
4
2
Forward
All breakers closed
4
Reverse
2
Forward
Breaker 1 opens
Application Notes
4
Strong
Source
2
4
Strong
Source
2
P3041ENa