ABB Relion Technical Manual page 121

1MRK 502 048-UUS A
Technical manual
Internal/
Neg.Seq. Diff
External
Current
Fault
discrimin
Contributions
OpNegSeqDiff=On
IBIAS
a
b>a
b
Constant
BLKNSSEN
BLKNSUNR
BLOCK
PU_A
PU_B
PU_C
ANSI05000167 V1 EN
Figure 39: Transformer differential protection simplified logic diagram for internal/
external fault discriminator
TRIPRES_A
TRIPRES_B
TRIPRES_C
TRIPUNRE_A
TRIPUNRE_B
TRIPUNRE_C
TRNSSENS
TRNSUNR
ANSI05000278 V1 EN
Figure 40: Transformer differential protection internal grouping of tripping signals
ator
AND
OR
OR
OR
Section 6
Differential protection
EXTFAULT
INTFAULT
TRNSSENS
t
0
AND
en05000167_ansi.vsd
TRIPRES
TRIPUNRE
TRIP
OR
en05000278_ansi.vsd
115