ABB Relion 670 series, Applications Manual

Page: 304 / 760

PHS Zm
X0 1.44 X0
³ ×
EQUATION1310 V1 EN-US
(Equation 303)
where:
X1
Zm
is the reactive reach for the zone to be covered by FDPSPDIS, and the constant
1.44 is a safety margin
X0
Zm
is the zero-sequence reactive reach for the zone to be covered by FDPSPDIS
The reactive reach in reverse direction is automatically set to the same reach as for forward
direction. No additional setting is required.
Fault resistance reach
M13142-103 v5
The resistive reach must cover
RFPE for the overreaching zone to be covered, mostly zone 2.
Consider the longest overreaching zone if correct fault selection is important in the
application. Equation 304 gives the minimum recommended resistive reach.
min
1.1
zm
RFFwPE
RFPE
³ ×
EQUATION1312 V2 EN-US
(Equation 304)
where:
RFPE
Zm
is the setting RFPE for the longest overreaching zone to be covered by FDPSPDIS .
The security margin has to be increased to at least 1.2 in the case where φloop<60° to avoid
that FDPSPDIS characteristic shall cut off some part of the zone measurement characteristic.
Phase-to-earth fault in reverse direction
M13142-151 v4
Reactive reach
M13142-153 v2
The reactive reach in reverse direction is the same as for forward so no additional setting is
required.
Resistive reach
M13142-156 v4
The resistive reach in reverse direction must be set longer than the longest reverse zones. In
blocking schemes it must be set longer than the overreaching zone at remote end that is used
in the communication scheme. In equation 305 the index ZmRv references the specific zone to
be coordinated to.
min ZmRv
RFRvPE 1.2 RFPE
³ ×
EQUATION1316 V1 EN-US
(Equation 305)
Phase-to-phase fault in forward direction
M13142-168 v2
Reactive reach
M13142-170 v3
The reach in reactive direction is determined by phase-to-earth reach setting
X1. No extra
setting is required.
Resistive reach
M13142-173 v4
In the same way as for phase-to-earth fault, the reach is automatically calculated based on
setting X1. The reach will be X1/tan(60°) =X1/√(3).
Section 7 1MRK 505 343-UEN B
Impedance protection
298
Application manual