ABB REB670 Series Applications Manual page 121

1MRK 505 370-UEN D
Version of REB670 IED
1Ph; 2-zones, 12-bays BBP (B21)
1Ph; 2-zones, 24-bays BBP (B31)
)
* with just one CT input from bus-section bay
Please note that Table
contain any VT inputs.
For station with just one CT 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.
6.1.4.5 H-type busbar arrangements
The H-type stations are often used in transmission and sub-transmission networks as load-
centre substations, as shown in Figure 56. These arrangements are very similar to the single
busbar station with sectionalizer or bus-section breaker, but are characterized by very limited
number of feeder bays connected to the station (normally only two OHL and two
transformers).
01
ZA
03
IEC06000121 V1 EN-US
Figure 56: Example of H-type station
The requirement for the busbar protection scheme for this type of station may differ from
utility to utility. It is possible to apply just one overall differential zone, which protects both
busbar sections. However, at an internal fault on any of the two buses all feeder circuit
breakers have to be tripped, which will cause loss of supply to all loads connected to this
station. Some utilities prefer to have two differential zones, one for each bus section.
The most common setups for this type of station are given in the following table.
Busbar protection REB670
Application manual
16 is given for the preconfigured versions of REB670 which do not
02
BS
ZB
04
xx06000121.vsd
Total number of Number of REB670 IEDs
feeders in both busbar required for the scheme
sections
3/6
)
11* /22
3/6
)
23* /46
Section 6
Differential protection
M6644-3 v5
115