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Functions
2.2 Automatic reclosure function (optional)
The integrated automatic reclosing function allows up to 8 reclosing attempts. The first four reclose cycles may
operate with different parameters (action and dead times, single-/three-pole). The parameters of the fourth
cycle apply to the fifth cycle and onwards.
Selectivity before Reclosure
In order for automatic reclosing to be successful, all faults occurring on the entire line length must be cleared
at both line ends simultaneously — as quickly as possible. Therefore, an instantaneous protection element is
usually set to operate before the automatic reclose function initiates a reclosure. (Figure 2-5). A limited unse-
lectivity in favour of fast simultaneous tripping is accepted here because reclosing will be performed in any
case.
Figure 2-5
If the fault protection features a so-called reclose stage, 7VK61 generates the signal „AR 1.CycZoneRel"
for its release for as long as the reclose function is ready for reclosure after tripping.
If the feeder protection is capable of activating its reclose stage for single-pole faults but not for multi-pole faults,
the automatic reclose function can supply the signal „AR 1.CycZoneRel" in addition to the signal „AR
Program1pole". This signal indicates that the automatic reclose function initiates reclosure only after single-
pole tripping, but not after three-pole tripping i.e., the reclose function is only programmed to single-pole reclo-
sure.
Initiation
Initiation of the automatic reclosing function means recording of the first trip signal of a system fault generated
by a protection device which interacts with the 7VK61. In case of multiple reclosing, initiation therefore only
takes place once with the first trip command. The storage of this first trip signal is the prerequisite for all sub-
sequent actions of the automatic reclosing function. The initiation is important when the first trip command has
not appeared before expiry of an action time (see below under „Action times").
Automatic reclosure is not started if the circuit breaker has not been ready for at least one OPEN-CLOSE-
OPEN–cycle at the instant of the first trip command. This can be achieved by setting parameters. For further
information, please refer to „Interrogation of Circuit Breaker Ready State".
Each short-circuit protection function can be parameterized as to whether it should operate with the automatic
reclose function or not, i.e. whether it should start the reclose function or not. The same goes for external trip
commands applied via binary input and/or the trip commands generated by the teleprotection via permissive
or intertrip signals.
44
Reach control before first reclosure, using distance protection
SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009
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