Ormazabal ekor.rps - Phase Directional by Sequences (67)

IG-150-EN version 04; 03/10/16
63
General instructions
ekor.rps
Protection functions. Description and settings
4.6.2. Phase directional by sequences (67)
Operation
Negative sequence directional
The direction is determined comparing the negative
sequence voltage and current, being I
2
higher than a
threshold and V
2
higher than a threshold.
1
2
3
90 - setting angle < arg (I
2
) – arg 92 (V
2
) < 270 - setting angle
1
Trip zone
2
Locking zone
3
Setting angle
Figure 4.5. Negative sequence directional
Negative sequence Directional Locking
1. If the negative sequence voltage is lower than a
threshold (Polarization V setting) the positive sequence
directional is carried out.
2. If the negative sequence current is lower than a
threshold (0.068 A) the previous selection is maintained.
Positive sequence directional
The direction is determined comparing the positive
sequence voltage and current.
There is a 5
th
zone between the locking zone and the trip zone,
for which the present directional status is maintained.
1
2
4
3
90 - setting angle > arg I
1
) – arg (V
1
) > 270 - setting angle
1
Locking zone
2
Tripping zone
3
Angle covered by the tripping zone
4
Setting angle
Figure 4.6. Positive sequence directional