ABB Relion 670 series, Technical Reference Manual

Page: 345 / 1232

6.10.2.6 Simplified logic diagrams
Figure 110 presents schematically the creation of the phase-to-phase and phase-to-
ground operating conditions. Consider only the corresponding part of measuring and
logic circuits, when only a phase-to-ground or phase-to-phase measurement is
available within the IED.
ANSI09000149-2-en.vsd
AND
AND
AND
Bool to
integer
DLECND
STPG
STPP
IRELPG
IRELPP
BLOCK
AND
Load encroachment block
0
20ms
0
10ms
0
15ms
0
15ms
0
3 I IMinPUPG
<
0 max
3 0 _
3
100
I BLK PP
I Iph
< ×
0
3 0.5 I IMinPUPG
³ ×
0
3 0 _
3
100
max
I Enable PG
I Iph
³ ×
ANSI09000149 V2 EN
Figure 178: Phase-to-phase and phase-to-ground operating conditions (residual
current criteria)
A special attention is paid to correct phase selection at evolving faults. A PHSEL
output signal is created as a combination of the load encroachment characteristic and
current criteria, refer to figure
110 . This signal can be configured to STCND functional
input signals of the distance protection zone and this way influence the operation of the
phase-to-phase and phase-to-ground zone measuring elements and their phase related
pickup and tripping signals.
Figure 111 presents schematically the composition of non-directional phase selective
signals NDIR_A (B or C). Internal signals ZMn and ZMmn (m and n change between
A, B and C according to the phase) represent the fulfilled operating criteria for each
separate loop measuring element, that is within the characteristic.
1MRK505222-UUS C
Section 6
Impedance protection
339
Technical reference manual