ABB RER670 Applications Manual page 144

Section 7
Impedance protection
138
Start
CharStartZ<: It is used to select the underimpedance start characteristic. Set this to
Quadrilateral.
X1Start: This is to set positive sequence reactance reach of the starting element
quadrilateral characteristic. It will be set to operate for all faults within the
protected area.
Therefore, set the X1Start to 150% of zone 3 reach. Zone 3 reach being 20.16
Ohm, set X1Start to 1.5 x 20.16 = 30.24 Ohm.
RFPEStart: This is used to set the forward and reverse resistive reach for PE
starting element. It will be set to operate for all faults within the protected area. To
provide maximum coverage for the high resistive faults, it may be set as high as
possible subject to check of possibility against load point encroachment.
Therefore, set this to 80% of the setting RLd resistive reach of the starter. The
setting RLd being 62.7 Ohm, the RFPEStart can be set to 0.8 x 62.7 = 50.16 Ohm.
I0MinOp: This is the minimum operating current of residual overcurrent start as %
of IBase. Set this to 10% IB.
KI0Stab: The stabilizing factor to prevent operation of the residual overcurrent start
caused by an unbalance or dissimilar CT behaviour in the event of high short
circuit currents. Set this to 0.8.
Direction
ArgNegRes: This is the angle for blinder in the second quadrant. Set this to 120
deg.
ArgDir: This is the angle of setting in the fourth quadrant. Set this to 15 deg.
Zone 1
OpZ1: Set this to On.
DirModeZ1: This is used to set the zone 1 direction mode. Set this to Forward.
PhSelModeZ1: This is used to enable the measuring loops of zone 1. Set this to
Phsel logic.
LEModeZ1: This is used to operate the load discrimination characteristic of zone 1.
Set this to On.
LCModeZ1: This is used to enable/disable the adaptive load compensation mode of
zone 1. Set this to On.
X1FwZ1: This is used to set the forward positive sequence reactance reach of zone
1 in Ohm/p. The recommended setting is 90% of the protected line length.
Therefore, set the X1FwZ1 to 0.9 x 50.0 x 0.112 = 5.6 Ohm.
REoverRLZ1: It provides zero sequence compensation for phase-to-earth faults.
1MRK 506 375-UEN A
GUID-0305F9F3-4C8A-488C-AA8F-BBCB055FF479 v2
GUID-464CA6EE-24D9-4F19-972C-F1EE1D4B9FFE v2
GUID-A055E2EB-4480-4116-BAC4-7132823BD663 v2
Railway application RER670 2.2 IEC
Application manual