ABB ret650 - Page 113

IdUnre
IDL1MAG
2nd
Harmonic
5th
Harmonic
Wave
block
IDL1
AND
Cross Block
from L2 or L3
OpCrossBlock=On
OR
1
IBIAS
TRIPUNREL1
STL1
TRIPRESL1
BLK2HL1
BLKWAVL1
en06000545.vsd
a
b
b>a
OR
AND
Cross Block
to L2 or L3
AND
AND
AND
BLKUNRES
BLOCK
BLKRES
BLK5HL1
S
w
i
t
c
h
o
n
t
o
f
a
u
l
t
l
o
g
i
c
IEC06000545 V1 EN
Figure 39: Transformer differential protection simplified logic diagram for Phase
L1
IEC05000167-TIFF V1 EN
Figure 40: Transformer differential protection simplified logic diagram for
internal/external fault discriminator
1MRK 504 135-UEN A Section 6
Differential protection
107
Technical manual