Ormazabal ekor.rps - Page 76

IG-150-EN version 04; 03/10/16
76
Protection functions. Description and settings General instructions
ekor.rps
As the sensitive neutral units allow the trip with forwards
and backwards faults, the characteristics will be as follows.
1
Backwards
2
Forwards
Figure 4.16. Forwards faults and backwards faults
I*sen(φ) directional
In order to allow the picking up of the directional unit the
following conditions must be fullled:
1. Exceed a V
n
minimum threshold.
2. The minimum current I
minimum
=I
ns
 sen (j-j
c
) must
exceed the minimum threshold in absolute value. If the
sign is negative, the fault is forwards. If it is positive it is
backwards.
3. For forwards faults the angle between the current and
the voltage, displaced the maximum torque angle, and
must be between 187 and 353.
4. 187<ang(I
0
)–angle(V
0
)+characteristic angle<353.
5. For the angle between the current and the voltage,
displaced the maximum torque angle, and must be
between 7 and 173.
7<ang(I
0
)–angle(V
0
)+characteristic angle<173.
I·sin ( v – i – φ )
=
(
Im(V) ⋅ cos(φ) + Re(V) ⋅ sin(φ)
)
⋅ Re(I) +
(
Re(V) ⋅ cos(φ) – Im(V) ⋅ sin(φ)
)
⋅ Im(I)
│ V │




Figure 4.17. I*sen(φ) directional