ABB REB670 Series Applications Manual page 122

Section 6
Differential protection
Table 17:
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)
Please note that Table
contain any VT inputs.
For station with double zone protection and just one set of CTs in the bus-section bay, it
might be required, depending on the client requirements, to provide the special scheme for
disconnection of bus-section CT when the bus-section CB is open. For more information, refer
to Figure 47.
6.1.4.6 Double circuit breaker busbar arrangement
The circuit breaker, disconnectors and instrument transformers are duplicated for every
feeder, as shown in Figure 57.
QA1 QA2
BI1
IEC06000018 V1 EN-US
Figure 57: Example of double breaker station
This is an extremely flexible solution. In normal service all breakers are closed. The requirement
for busbar protection scheme is that the scheme must have two independent differential
zones, one for each busbar. If there is an internal fault on one of the two buses all circuit
breakers associated with the faulty busbar have to be tripped, but supply to any load will not
be interrupted. The tripping logic for the circuit breaker failure protection must be carefully
arranged.
The most common setups for this type of busbar arrangement are described in the following
table.
Table 18:
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)
116
Typical solutions for H-type stations
17 is given for the preconfigured versions of REB670 which do not
QA1 QA2 QA1
BI2 BI1 BI2 BI1
Typical solutions for double circuit breaker busbar arrangement
Number of differential
zones/number of
feeders per zone
1/4
2/3
NA
NA
NA
QA2 QA1 QA2 QA1
BI2 BI1 BI2 BI1
Numbers of feeders
per station
4
4/8
6/12
6/12
12/24
1MRK 505 370-UEN D
Number of REB670 IEDs required for
the scheme
1
1
NA
NA
NA
ZA
ZB
QA2
BI2
xx06000018.vsd
Number of REB670 IEDs required for
the scheme
2
1/2
3/6
3/6
3/6
Busbar protection REB670
Application manual
M6645-3 v5