ABB Relion 670 Series Applications Manual page 34

Section 2
Application
pickup can be used when high sensitivity is required from busbar differential protection (that is,
energizing of the bus via long line).
Overall operating characteristic of the differential function in the IED is shown in figure 2.
DiffOperLevel
SensOperLevel
IEC06000142 V2 EN-US
Figure 2:
Integrated overall check zone feature, independent from any disconnector position, is available. It can be
used in double or triple 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, triple busbar with or without transfer bus, breaker-and-a-half 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 or more differential zones when required by substation topology (that is
load-transfer)
• Easy zone merging initiated by closing of bus-sectionalizing disconnectors
• 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 faults within the blind spot or
the end zone between bay CT and bay circuit breaker. Therefore the IED offers best possible coverage
for such faults in feeder and bus-section/bus-coupler bays.
28
s=0.53
IED operating characteristic
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Sensitive
differential
protection
Operate
region
Differential protection
operation characteristic
SensIinBlock
I [Primary Amps]
in
1MRK 505 370-UUS Rev. K
IEC06000142-2-en.vsdx
Busbar protection REB670
Application manual