ABB Relion 670 series - Setting of Reach in Resistive Direction

8.13.4.7 Setting of reach in resistive direction
Set the resistive reach R1 independently for each zone.
Set separately the expected fault resistance for phase-to-phase faults RFPP and for the
phase-to-ground faults RFPG for each zone. For each distance zone, set all remaining
reach setting parameters independently of each other.
The final reach in resistive direction for phase-to-ground fault loop measurement
automatically follows the values of the line-positive and zero-sequence resistance, and at
the end of the protected zone is equal to equation
139.
( )
1
R 2 R1 R0 RFPG
3
= × + +
ANSIEQUATION2303 V1 EN (Equation 390)
2X1Zx X0Zx
arctan
2 R1Zx R0Zx
loop










EQUATION2304 V2 EN (Equation 391)
Setting of the resistive reach for the underreaching zone 1 should follow the condition to
minimize the risk for overreaching:
RFPG 4.5 X1
£ ×
ANSIEQUATION2305 V1 EN (Equation 392)
The fault resistance for phase-to-phase faults is normally quite low, compared to the fault
resistance for phase-to-ground faults. To minimize the risk for overreaching, limit the
setting of the zone 1 reach in resistive direction for phase-to-phase loop measurement to:
61
R
FPPZx X Zx


IECEQUATION2306 V3 EN (Equation 393)
Note that RLdFwd and RldRev are not only defining the load encroachment boundary.
They are used internally as reference points to improve the performance of the phase
selection. In addition, they define the impedance area where the phase selection element
gives indications, so do not set RLdFwd and RldRev to excessive values even if the load
encroachment functionality is not needed (that is, when the load is not encroaching on the
distance zones). Always define the load encroachment boundary according to the actual
load or in consideration of how far the phase selection must actually reach.
1MRK 506 369-UUS - Section 8
Impedance protection
Line distance protection REL670 2.2 ANSI 429
Application manual