ABB Relion 650 Series Technical Manual page 133

1MRK 506 326-UUS B
where:
V | and |I
1
V1Level ,
I1LowLevel
IMaxLoad
Fault evaluation and selection logic
The phase selection logic has an evaluation procedure that can be simplified according to figure
71. 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.
DeltaIA
DeltaVA
Sequence based
function
AB fault
AG fault
3 Phase fault
IA Valid
BLOCK
ANSI06000386 V1 EN-US
Figure 71:
Load encroachment logic
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
phase identification with load encroachment for mho (FMPSPDIS, 21) function but the influence on
the zone measurement can be switched Enabled/Disabledin the respective Five zone distance
protection, mho characteristic (ZMOPDIS) function.
The outline of the characteristic is presented in figure 72. As illustrated, the resistive reach in
forward and reverse direction and the angle of the sector is the same in all four quadrants. The
reach for the phase selector will be reduced by the load encroachment function, as shown in figure
72.
Blinder
Blinder provides a mean to discriminate high load from a fault. The operating characteristic is
illustrated in figure 72. There are six individual measuring loops with the blinder functionality.
Three phase-to-ground loops which estimate the impedance according to
Line distance protection REL650
Technical manual
| are the positive sequence voltage and current magnitude
1
are the setting of limits for positive sequence voltage and current
is the setting of the maximum load current
a
b
a
b
OR
Simplified diagram for fault evaluation, phase A
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a>b
FaultPriority
c
then c=a
Adaptive release
dependent on result
else c=a
from Delta logic
a<b
c
then c=b
OR
else c=a
&
PU_A
en06000386_ansi.vsd
Section 5
Impedance protection
SEMOD153832-307 v3
SEMOD153832-312 v3
127