ABB REG670 - Signals

Internal/
External
Fault
discrimin
ator
t
STL1
STL2
STL3
>1
&
EXTFAULT
INTFAULT
TRNSSENS
T
R
N
S
U
N
R
IEC05000167-2-en.vsd
Constant
IBIAS
a
b
b>a
Neg.Seq. Diff
Current
Contributions
OpNegSeqDiff=On
&
IEC05000167-TIFF V2 EN
Figure 40: Transformer differential protection simplified logic diagram for
external/internal fault discriminator
en05000278.vsd
TRIPRESL1
TRIPRESL2
TRIPRESL3
OR
TRIPRES
TRIPUNREL1
TRIPUNREL2
TRIPUNREL3
OR
TRIPUNRE
OR
TRIP
TRNSUNR
TRNSSENS
IEC05000278 V1 EN
Figure 41: Transformer differential protection internal grouping of tripping
signals
Section 6 1MRK502052-UEN B
Differential protection
138
Technical manual