ABB Relion 670 Series Product Manual page 4

Busbar protection REB670
Customized
Product version: 1.2
Diff Oper Level
Sensitive Oper Level
IEC06000142 V1 EN
Figure 1. REB670 operating characteristic
Integrated overall check zone feature, independent from any
disconnector position, is available. It can be used in double
busbar stations to secure stability of the busbar differential
protection in case of entirely wrong status indication of
busbar disconnector in any of the feeder bays.
Flexible, software based dynamic Zone Selection enables
easy and fast adaptation to the most common substation
arrangements such as single busbar with or without transfer
bus, double busbar with or without transfer bus, one-and-a-
half breaker stations, double busbar-double breaker stations,
ring busbars, and so on. The software based dynamic Zone
Selections ensures:
• Dynamic linking of measured CT currents to the
appropriate differential protection zone as required by
substation topology
• Efficient merging of the two differential zones when
required by substation topology (that is load-transfer)
• Selective operation of busbar differential protection
ensures tripping only of circuit breakers connected to
the faulty zone
• Correct marshaling of backup-trip commands from
internally integrated or external circuit breaker failure
protections to all surrounding circuit breakers
• Easy incorporation of bus-section and/or bus-coupler
bays (that is, tie-breakers) with one or two sets of CTs
into the protection scheme
• Disconnector and/or circuit breaker status supervision
Advanced Zone Selection logic accompanied by optionally
available end-fault and/or circuit breaker failure protections
ensure minimum possible tripping time and selectivity for
4
Sensitive
differential
protection
Operate
region
Sens Iin Block
s=0.53
Differential protection
operation characteristic
I [Primary Amps]
in
en06000142.vsd
faults within the blind spot or the end zone between bay CT
and bay circuit breaker. Therefore REB670 offers best
possible coverage for such faults in feeder and bus-section/
bus-coupler bays.
Optionally available circuit breaker failure protection, one for
every CT input into REB670, offers secure local back-up
protection for the circuit breakers in the station.
Optionally available four-stage, non-directional overcurrent
protections, one for every CT input into REB670, provide
remote backup functionality for connected feeders and
remote-end stations.
Optionally available voltage and frequency protection
functions open possibility to include voltage release criterion
for busbar protection or to integrate independent over-, under-
voltage protection for the bus in the busbar protection IED.
Optionally available over-current, thermal overload and
capacitor bank protection functions open possibilities to
integrate protection of shunt reactors and shunt capacitor
banks into the busbar protection IED.
It is normal practice to have just one busbar protection IED
per busbar. Nevertheless some utilities do apply two
independent busbar protection IEDs per zone of protection.
REB670 IED fits both solutions.
A simplified bus differential protection for multi-phase faults
and earth faults can be obtained by using a single, one-phase
REB670 IED with external auxiliary summation current
transformers.
1MRK505273-BEN D
ABB