1 2
A
B
EnergizingCheck
Line voltage
Bus voltage
ANSI10000078-4-en.vsd
VLiveBusEnerg > 50 - 120 % of GblBaseSelBus
VLiveLineEnerg > 50 - 120 % of GblBaseSelLine
VDeadBusEnerg < 10 - 80 % of GblBaseSelBus
VDeadLineEnerg < 10 - 80 % of GblBaseSelLine
VMaxEnerg < 50 - 180 % of GblBaseSelBus and/or
GblBaseSelLine
ANSI10000078 V4 EN
Figure 300: 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 (Live) if the voltage is above the set value for
VLiveBusEnerg or VLiveLineEnerg of the base voltages GblBaseSelBus and
VGblBaseSelLine, which are defined in the Global Base Value groups, according to the
setting of GblBaseSelBus and GblBaseSelLine; in a similar way, the equipment is
considered non-energized (Dead) if the voltage is below the set value for VDeadBusEnerg
or VDeadLineEnerg of the respective Global Base Value groups. A disconnected line can
have a considerable potential due to 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.
15.1.2.4 Voltage selection
The voltage selection function is used for the connection of appropriate voltages to the
synchronism check, synchronizing and energizing check functions. For example, when
the IED is used in a double bus arrangement, the voltage that should be selected depends
on the status of the breakers and/or disconnectors. By checking the status of the
Section 15 1MRK 506 369-UUS -
Control
638 Line distance protection REL670 2.2 ANSI
Application manual
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