ANSI11000232-3-en.vsd
AND
INPUT1
INPUT2
INPUT3
INPUT4N
OUT
NOUT
Start signal to
remote side
Start signal from
remote side
Release of line
differential
protection trip
LDLPSCH (87L)
CTFAIL
OUTSERV
BLOCK
TRIP
TRL1
TRL2
TRL3
TRLOCAL
TRLOCL1
TRLOCL2
TRLOCL3
TRREMOTE
DIFLBLKD
LDRGFC (11REL)
I3P*
U3P*
BLOCK
BLKCV
BLKUC
BLK3I0
BLKUV
REMSTUP
START
STCVL1L2
STCVL2L3
STCVL3L1
STUC
ST3I0
STUV
ANSI11000232 V3 EN
Figure 56: Local release criterion configuration for line differential protection
7.2.3 Setting guidelines
GlobalBaseSel: Selects the global base value group used by the function to define IBase,
VBase and SBase as applicable.
tStUpReset: Reset delay of the startup signal. The default value is recommended.
Settings for phase-phase current variation subfunction are described below.
Enable CV: Enabled/Disabled, is set Enabled in most applications
Pick Up ICV: Level of fixed threshold given in % of IBase. This setting should be based
on fault calculations to find the current increase in case of a fault at the point on the
protected line giving the smallest fault current to the protection. The phase current shall be
calculated for different types of faults (single phase-to-ground, phase-to-phase to ground,
phase-to-phase and three phase short circuits) at different switching states in the network.
In case of switching of large objects (shunt capacitor banks, transformers, and so on) large
change in current can occur. The Pick Up ICV setting should ensure that all multi-phase
faults are detected.
Time Delay CV: Time delay of zero sequence overcurrent criterion. Default value 0.002
s is recommended
Settings for zero sequence current criterion subfunction are described below.
Enable 3I0: Enabled/Disabled, is set Enabled for detection of phase-to-ground faults with
high sensitivity
Section 7 1MRK 506 369-UUS -
Differential protection
154 Line distance protection REL670 2.2 ANSI
Application manual
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