ABB Relion 670 Series Technical Reference Manual page 204

Section 6
Impedance protection
198
X
R1PG+RNFw
RFRvPG
X1FwPG+XNFw
RFRvPG
j
N
RFRvPG
ANSI09000625 V1 EN
Figure 89: Characteristic for the phase-to-ground measuring loops, ohm/loop
domain
(Ohm/loop)
XNFw
RFFwPG
XNRV
XNRv
=
XNRV
=
XNFW
XNFW
RNFw
j j
N N
R
RFFwPG
X1RvPG+XNRv
RFFwPG
ANSI09000625-1-en.vsd
1MRK505222-UUS C
-
X PG 0 X FwPG 1
=
3
-
X RvPG 1
X PG X RVPG 0 1
-
= X PE X RVPE 0 1
= ×
XNFw
3
3
X FwPG 1
- -
X PE X FWPE X PG X FWPG 0 0 1 1
=
-
R PG 0 R PG 1
3
3
=
3
(Ohm/loop)
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