ABB REL670 2.2 IEC - Page 329

Equation 274 and 275 are is also valid for three-phase fault. The proposed margin
of 25% will cater for the risk of cut off of the zone measuring characteristic that
might occur at three-phase fault when FRPSPDIScharacteristic angle is changed
from 60 degrees to 90 degrees or from 70 degrees to 100 degrees (rotated 30° anti-
clock wise).
R1Zm
X1Zm
X1Zm
0.5*RFPPZm
R1Zm
0.5*RFPPZM
0.5*RFPPZm
0.5*RFPPPm
0.5*RFPPZm
R
70
j
)phase/( W
70
j
PHS
Zm
RFFwPP5.0 ×
RFRvPP5.0 ×
RFRvPP5.0 ×
0.5*RFPPZm
en08000249.vsd
tan 70°
1X
PHS
tan 70°
1X
PHS
X1
R1PP=
R1PP=
X
)phase/( W
IEC08000249 V1 EN-US
Figure 164: Relation between measuring zone and FRPSPDIS characteristic
for phase-to-phase fault for φline>70° (setting parameters in italic)
1MRK 506 369-UEN B Section 8
Impedance protection
Line distance protection REL670 2.2 IEC 323
Application manual