ABB Relion 670 series, Техническое руководство

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|I
2
|<0.1 · maxIph
3:
|3I
0
|>maxIph ·
3I0BLK_PP
or
|I
2
|<maxIph · I2ILmax
where:
maxIph is the maximum of the phase currents IA, IB and IC
INRelPG is the setting parameter for 3I0 limit for release of phase-to-ground
fault loops
|I
2
| is the magnitude of the negative sequence current
I2ILmax is the setting parameter for the relation between negative sequence
current to the maximum phase current in percent of IBase
3I0BLK_PP is the setting parameter for 3I
0
limit for blocking phase to phase
measuring loops
Fault evaluation and selection logic
SEMOD153832-307 v3
The phase selection logic has an evaluation procedure that can be simplified according to figure
118 . Only phase A is shown in the figure. If the internal signal 3 Phase fault is activated, all four
outputs PICKUP, PU_A, PU_B and PU_C gets activated.
a
b
a>b
then c=a
else c=a
c
DeltaIA
DeltaVA
FaultPriority
Adaptive release
dependent on result
from Delta logic
a
b
a<b
then c=b
else c=a
c
OR
AB fault
AG fault
Sequence based
function
OR
3 Phase fault
IA Valid
&
BLOCK
PU_A
en06000386_ansi.vsd
ANSI06000386 V1 EN-US
Figure 118: Simplified diagram for fault evaluation, phase A
Load encroachment logic
SEMOD153832-312 v3
Each of the six measuring loops has its own load (encroachment) characteristic based on the
corresponding loop impedance. The load encroachment functionality is always activated in faulty
1MRK 502 066-UUS B Section 7
Impedance protection
251
Technical manual