ABB Relion 670 Series Applications Manual page 107

1MRK 505 370-UUS Rev. K
N.O.
N.C.
IEC06000085 V1 EN-US
Figure 44:
Circuit breaker replica
The circuit breaker position from a bay shall be given to the busbar protection when the position of this
particular breaker can influence the busbar protection operation. Typical examples are Blind Spot
protection in Bus-section and Bus-coupler bays or End Fault Protection in feeder bays. In both cases the
measuring range of a busbar protection is limited by the CT location. By additionally recording the CB
position of a feeder or a coupler the zone between the CT and the CB can be better protected while CB
is open. However in such cases it is of utmost importance to connect the CB closing command to the
busbar protection in order to include again the CT current to the busbar protection zones in time. It is as
strongly recommended to always use Scheme1_RADSS for all CBs positions connected to the IED in
order to minimize any risk of possible problems due to late inclusion of CT current to the relevant
differential zones.
Line disconnector replica
The line disconnector position from a feeder bay might be required for busbar protection under certain
circumstances. Typical example is when the line disconnector 989 and associated grounding switch QC1
are located between CT and protected busbar as indicated in Figure 45.
189 289
152
989
en06000086_ansi.vsd
ANSI06000086 V1 EN-US
Figure 45:
Busbar protection REB670
Application manual
BBP
input „closed"
input „open"
current
assignment
Scheme2_INX
ZA
ZB
189G
Feeder bay layout when line disconnector position might be required for busbar
protection
© 2017 - 2021 Hitachi Power Grids. All rights reserved
arcing possible
2)
closed
open
1
0
1)
1
0
1
0
1) disconnector supervision running
2) BI „closed" should change before arcing distance
Section 6
Differential protection
1)
en06000085.vsd
SEMOD127523-79 v3
SEMOD127523-82 v4
101