ABB Relion 650 Series Technical Manual page 102

Section 5
Impedance protection
³
3 I
0
3 0
³
3 I
0
<
3I
0
<
3 I
0
ANSI09000149 V2 EN-US
Figure 50: Phase-to-phase and phase-to-ground operating conditions (residual current
A special attention is paid to correct phase selection at evolving faults. A DLECND output signal is
created as a combination of the load encroachment characteristic and current criteria, refer to
figure 50. 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 51
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.
96
×
0.5 IMinPUPG
AND
I Enable PG _
×
Iph
max
100
BLOCK
IMinPUPG
AND
3 0 I BLK _ PP
×
Iph
max
100
criteria)
presents schematically the composition of non-directional phase selective signals
© Copyright 2011 ABB Power Grids. All rights reserved
Load encroachment block
0
15ms
Bool to
integer
AND 0
15ms
10ms 0
0 20ms
1MRK 506 326-UUS B
IRELPG
STPG
DLECND
AND
STPP
IRELPP
ANSI09000149-2-en.vsd
Line distance protection REL650
Technical manual