GE P444

P
44x/EN AP/Hb6
Application Notes
(AP) 5
-104 MiCOM P40 Agile
P442, P444
4.8.1.3 Phase selection
The phase is selected in the same way as for distance protection except that the current
threshold is reduced (I ≥ 0.05 x In and V ≥ 0.1 x Vn)
Note: If the phase has not been selected within one cycle, a three-phase selection is made
automatically.
4.8.2 Tripping Logic
Legend for Tripping Logic Diagrams (DEF)
Abbreviation Definition
Vr> Threshold of residual or zero sequence voltage (3V0)
IRev
Threshold of residual current (Setting, 0,6IN)
Forward Forward directional with zero/negative sequence polarisation
Reverse Reverse directional with zero/negative sequence polarisation
DEF blocking Blocking of DEF element
Carrier Receive DEF
Carrier received for the principal line protected (same channel as
distance protection)
Iev Threshold of residual current (0.6 x Ied)
Tripping mode Single or three-phase tripping (selectable)
Z< starting
Convergence of at least 1 of the 6 loops within the tripping characteristic
(internal starting of the distance element)
t_cycle Additional time delay (150 ms) of 1 pole AR cycle
t_delay Tripping time delay
t_trans Carrier Send delay
&
&
&
&
1
1
1
&
Vr>threshold
Ied
threshold
Forward decision
Reverse decision
Iev threshold
Single phase selection
2 Pole or 3 Pole Selection
1 pole dead
SOTF
Z< starting
Independant
channels DIST/DEF
T
ripping mode
0
0
T
50ms
Forward Startup
TrSingle Phase ip
TThree Phase rip
P3042ENb
&
Carrier Received DEF
Blocking DEF
&
0
T
Time Delay
Block. Time Add.
Reverse decision
r>threshol
d
&
&
Three
Reversal Startup
Single
Carrier Send DEF
&
&
Figure 73: Directional comparison protection permissive scheme