ABB Relion 670 series, Applications Manual

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R
X
Distance measuring zone
Phase selection
”Quadrilateral” zone
(ohm/phase)
(ohm/phase)
en05000674.vsd
IEC05000674 V1 EN-US
Figure 177: Operation characteristic for FRPSPDIS in forward direction for three-phase
fault, ohm/phase domain
The result from rotation of the load characteristic at a fault between two phases is presented
in fig 178 . Since the load characteristic is based on the same measurement as the quadrilateral
characteristic, it will rotate with the quadrilateral characteristic clockwise by 30 degrees when
subject to a pure phase-to-phase fault. At the same time, the characteristic "shrinks" by 2/√3,
from the full RLdFw/RLdRv reach, which is valid at load or three-phase fault.
Section 7 1MRK 505 343-UEN B
Impedance protection
288
Application manual