ABB REG670 - Page 249

j
R1PP RFFwPP
X1FwPP
X1RvPP
RFFwPP
RFRvPP
RFFwPP
RFRvPP
RFRvPP
R
X
(Ohm/phase)
(Ohm/phase)
IEC11000418-1-en.vsd
j
0 1
3
X PE X RVPE
XNRV
-
=
0 1
3
X PE X FWPE
XNFW
-
=
0 1
3
X PG X FWPG
XNFW
-
=
0 1
3
X PG X RVPG
XNRV
-
=
0 1
3
X PE X RVPE
XNRV
-
=
0 1
3
X PE X FWPE
XNFW
-
=
2
2
2
2
2
2
j
N
N
j
IEC11000418 V1 EN
Figure 96: ZMFCPDIS Characteristic for the phase-to-phase measuring loops
Note that for ZMFCPDIS, the reverse zone ZRV, as well as any of
zones 3-5, that are set to DirMode=Reverse will get their operating
impedances inverted (rotated 180 degrees) internally in order to make
use of the main settings, which are the settings designated ‘Fw’.
Therefore, a reverse zone will have its Fw-settings (RFFwPPZRV,
X1FwPEZ3, and so on) applied in the third quadrant, that is, towards
the busbar instead of the line.
The fault loop reach in relation to each fault type may also be presented as in figure 84.
The main intention with this illustration is to make clear how the fault resistive reach
should be interpreted. Note in particular that the setting RFPP always represents the
total fault resistance of the loop, even while the fault resistance (arc) may be divided
into parts like for three-phase or phase-to-phase-to-earth faults. The R1 and jX1
represent the positive sequence impedance from the measuring point to the fault
location.
1MRK502052-UEN B Section 7
Impedance protection
243
Technical manual