ABB RET670 Applications Manual page 589

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1MRK504116-UUS C
Application manual
The energizing check function measures the bus and line voltages and compares them
to both high and low threshold values. The output is given only when the actual
measured conditions match the set conditions. Figure
where one (1) is energized and the other (2) is not energized. Power system 2 is
energized (DLLB) from substation 1 via the circuit breaker A.
~
VLiveBusEnerg > 50 - 120 % of VBaseBus
VLiveLineEnerg > 50 - 120 % of VBaseLine
VDeadBusEnerg < 10 - 80 % of VBaseBus
VDeadLineEnerg < 10 - 80 % of VBaseLine
VMaxEnerg < 50 - 180 % of VBaseBus and/or VBaseLine
ANSI10000078 V2 EN
Figure 224:
Principle for the energizing check function
The energizing operation can operate in the dead line live bus (DLLB) direction, dead
bus live line (DBLL) direction, or in both directions over the circuit breaker.
Energizing from different directions can be different for automatic reclosing and
manual closing of the circuit breaker. For manual closing it is also possible to allow
closing when both sides of the breaker are dead, Dead Bus Dead Line (DBDL).
The equipment is considered energized if the voltage is above set value of
VHighBusEnerg or VHighLineEnerg of the base voltage, and non-energized if it is
below set value of VLowBusEnerg or VLowLineEnerg of the base voltage. A
disconnected line can have a considerable potential because of factors such as
induction from a line running in parallel, or feeding via extinguishing capacitors in the
circuit breakers. This voltage can be as high as 50% or more of the base voltage of the
line. Normally, for breakers with single breaking elements (<330 kV) the level is well
below 30%.
When the energizing direction corresponds to the settings, the situation has to remain
constant for a certain period of time before the close signal is permitted. The purpose
of the delayed operate time is to ensure that the dead side remains de-energized and
that the condition is not due to temporary interference.
1
A
Bus voltage
Line voltage
EnergizingCheck
Section 3
IED application
224
shows two substations,
2
ANSI10000078-2-en.vsd
B
583

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