Function Block - ABB REG670 Technical Manual

1MRK502052-UEN B
6.1.3
Technical manual
inrush and CT saturation during external faults. A high set unrestrained differential
current protection element is included for a very high speed tripping at high internal
fault currents.
Included is an sensitive differential protection element based on the theory of negative
sequence current component. This element offers the best possible coverage of power
transformer windings turn to turn faults.

Function block

T2WPDIF
I3PW1CT1* TRIP
I3PW1CT2* TRIPRES
I3PW2CT1* TRIPUNRE
I3PW2CT2* TRNSUNR
TAPOLTC1 TRNSSENS
OLTC1AL START
BLOCK STL1
BLKRES STL2
BLKUNRES STL3
BLKNSUNR BLK2H
BLKNSSEN BLK2HL1
BLK2HL2
BLK2HL3
BLK5H
BLK5HL1
BLK5HL2
BLK5HL3
BLKWAV
BLKWAVL1
BLKWAVL2
BLKWAVL3
IDALARM
OPENCT
OPENCTAL
IDL1
IDL2
IDL3
IDL1MAG
IDL2MAG
IDL3MAG
IBIAS
IDNSMAG
IEC06000249_2_en.vsd
IEC06000249 V2 EN
Figure 30: T2WPDIF function block
Section 6
Differential protection
103