ABB Relion 670 Series Product Manual page 31

Busbar protection REB670
Version 2.2
logical value is zero (that is, CntrlExcludes). This option is
typically used when only normally closed auxiliary
contacts from the busbar disconnector are available to the
Zone Selection logic
At the same time, an additional feature for instantaneous or
time delayed disconnection or even inversion of the
connected bay current via separate logical signals is also
available. This feature is provided in order to facilitate for
bus-section or bus-coupler CT disconnection for tie-
breakers with a CT only on one side of the circuit breaker.
This ensures correct and fast fault clearance of faults
between the CT and the circuit breaker within these bays.
The same feature can be individually used in any feeder bay
to optimize Busbar differential protection performance,
when feeder circuit breaker is open. Thus, the end-fault
protection for faults between circuit breaker and the CT is
available. However, to use this feature circuit breaker
auxiliary contacts and closing command to the circuit
breaker shall be wired to the binary inputs of the IED.
Therefore, he IED offers best possible coverage for these
special faults between CT and circuit breaker in feeder and
bus-section/bus-coupler bays.
Within the Bay function block it is decided by a parameter
setting how this bay should behave during zone
interconnection (that is, load transfer). For each bay
individually one of the following three options can be
selected:
• Bay current is forced out from both zones during zone
interconnection (used for bus-coupler bays)
• Bay current is unconditionally forced into both zones
during zone interconnection (used in special applications)
• Bay current is connected to both zones during zone
interconnection if the bay was previously connected to
one of the two zones (typically used for feeder bays)
The third option ensures that the feeder, which is out of
service, is not connected to any of the two zones during
zone interconnection.
Within the Bay function block it is decided by a parameter
setting whether this bay should be connected to the check
zone or not. In this way the end user has simple control
over the bays, which shall be connected to the overall check
zone.
By appropriate configuration logic it is possible to take any
bay (that is, CT input) out of service. This can be done from
the local HMI or externally via binary signal. In that case all
internal current measuring functions (that is, differential
protection, sensitive differential protection, check zone,
breaker failure protection and overcurrent protection) are
disabled. At the same time, any trip command to this bay
circuit breaker can be inhibited.
Via two dedicated binary input signals it is possible to:
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• Trip only the bay circuit breaker (used for integrated OC
• Trip the whole differential zone to which this bay is
Finally dedicated trip binary output from the Bay function
block is available in order to provide common trip signal to
the bay circuit breaker from busbar differential protection,
breaker failure protection, backup overcurrent protection
and so on.
In this way the interface to the user is kept as simple as
possible and IED engineering work is quite straight forward.
Six-zone busbar differential protection
The six-zone busbar differential protection can provide
protection and monitoring for up to six freely configurable
low-impedance differential protection zones and up to
twenty-four freely configurable single-phase CT inputs,
which requires two TRM modules. For busbar IED
configuration, six types of function blocks are available:
• One busbar protection main function block, BDZSGAPC.
• Six differential zone function blocks, BZNPDIF_Zx, (1≤ x
• One check zone function block BCZPDIF.
• Five bus-section or bus-coupler bay function blocks
• Twenty four feeder bay function blocks BFPTRC_Fx, (1≤ x
• 128 switch status function blocks BDCGAPC.
Zone interconnection (Load transfer)
When this feature is activated the two integrated differential
protection zones are merged into one common, overall
differential zone. This feature is required in double busbar
stations when in any of the feeder bays both busbar
disconnectors are closed at the same time (that is, load
transfer). As explained in above section Bay each CT input
will then behave in the pre-set way in order to ensure
proper current balancing during this special condition. This
feature can be started automatically (when Zone Selection
logic determines that both busbar disconnectors in one
feeder bay are closed at the same time) or externally via
dedicated binary signal. If this feature is active for longer
time than the pre-set vale the alarm signal is given.
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protection tripping)
presently connected (used for backup-trip command from
either integrated or external bay circuit breaker failure
protection)
≤6).
Note that we refer to the six differential protection zones
as Zx, (1≤x≤6). Also sometimes we refer to the differential
protection zones as the main zones to distinguish them
from the check zone.
BICPTRC_x, (1≤ x ≤5).
Note that we also call a bus-section or bus-coupler bay as
a bus interconnector, and refer to its two sets CTs as CT1
and CT2 respectively.
≤24).
1MRK 505 373-BEN P
GUID-F7EB2E33-55A8-4665-B950-644E34DC5C4B v1
SEMOD120992-4 v4
31