ABB Relion 670 Series Applications Manual page 128

Section 6
Differential protection
152
ANSI11000239 V1 EN-US
Figure 62:
This type of busbar arrangement is very common. It is often preferred for larger installations. It provides
good balance between maintenance work requirements and security of supply. If needed, two busbars
can be split during normal service. The requirement for busbar protection scheme is that the scheme
must have two independent differential zones, one for each busbar. In case of an internal fault on one of
the two buses, bus-coupler circuit breaker and all feeder circuit breakers associated with the faulty bus
have to be tripped, leaving other busbar still in normal operation. Provision for zone selection,
disconnector replica and zone interconnection have to be included into the scheme design.
This type of busbar arrangement can be protected as described in the following table:
Table 20:
Version of REB670 IED
3PH; 2-zones, 4-bays BBP (A20)
3PH; 2-zones, 8-bays BBP (A31)
1Ph; 2-zones, 12-bays BBP (B20)
1Ph; 2-zones, 12-bays BBP (B21)
1Ph; 2-zones, 24-bays BBP (B31)
*) with just one CT input from bus-coupler bay
Please note that Table
inputs.
For station with just one CT in the bus-coupler bay, it might be required, depending on the client
requirements, to provide the special scheme for disconnection of bus-coupler CT when the bus-coupler
CB is open. For more info please refer to Figure 48.
Some principle overall drawings of how to use REB670 in this type of station are given in Figure
Figure 67.
122
189 289 189 289 189
152 152
Example of double busbar station
Typical solutions for double busbar stations
20 is given for the preconfigured versions of REB670 which do not contain any VT
© 2017 - 2021 Hitachi Power Grids. All rights reserved
289 189 289 189 289 189
152
152 152
ANSI11000239-1-en.vsd
Number of feeders in the
station (excluding bus-
coupler bay)
)
3*
)
7*
NA
)
11*
)
23*
1MRK 505 370-UUS Rev. K
ZA
ZB
289
152
Number of REB670 IED required for
the scheme
1
1
NA
3
3
Busbar protection REB670
63 to
Application manual