ABB RELION RET670 Applications Manual page 257

1MRK 504 163-UUS A
Transformer protection RET670 2.2 ANSI
Application manual
1
2
60°
8
6
4
3
IEC09000043 V1 EN-US
Figure 117: Relation between distance protection phase selection (FDPSPDIS)
(21) and impedance zone (ZMQPDIS) (21) for phase-to-ground fault
φloop>60° (setting parameters in italic)
1 FDPSPDIS (phase selection)(21) (red line)
2 ZMQPDIS (Impedance protection zone)(21)
RFltRevPG
3
PHS
4 ( X1 +XN)/tan(60°)
PHS
RFltFwdPG
5
PHS
RFPG
6
ZM
7 X1 +XN
PHS
8 φloop
X1
9 +XN
ZM
X
W
( / loop)
3 4
6
6
8
6
5
Section 8
Impedance protection
5
7
60°
R
W
( / loop)
7
IEC09000043_1_en.vsd
251