Siemens siprotec 7SD5, Руководство пользователя

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2 Functions
292
7SD5 Manual
C53000-G1176-C169-1
Sequence of a
Single-Pole and
Three-Pole Reclose
Cycle This operating mode is only possible with the appropriate device version and if this
was selected during configuration of the protection functions (address
110
, see also
Section 2.1.1.3). Of course, the circuit breaker must also be suitable for single-pole
tripping.
If the automatic reclosure function is ready, the short-circuit protection trips single-
pole for single-phase faults and three-pole for multi-phase faults. Under the general
settings (address
1156 Trip2phFlt
, see also Section 2.1.4.1) it can also be select-
ed that single-pole tripping takes place for two-phase faults without earth. Single-pole
tripping is of course only possible with short-circuit protection functions that can deter-
mine the faulty phase. The valid protection stage selected for reclosure ready state
applies for all fault types.
The automatic reclosure function is started in the event of a trip. Depending on the
type of fault, the (adjustable) dead time for the single-pole reclose cycle or the (sepa-
rately adjustable) dead time for the three-pole reclose cycle starts following the reset
of the trip command or opening of the circuit breaker (pole). After expiry of the dead
time, the circuit breaker receives a close command. At the same time, the (adjustable)
reclaim time is started. If the reclosure is blocked during the dead time following a
single-pole trip, immediate three-pole tripping can take place as an option (forced
three-pole coupling).
If the fault is cleared (successful reclosure), the reclaim time expires and all functions
return to their quiescent state. The fault is cleared.
If the fault is not cleared (unsuccessful reclosure), the short-circuit protection initiates
a final three-pole trip with the protection stage that is valid/selected when reclosure is
not ready. All faults during the reclaim time also lead to the issue of a final three-pole
trip.
After unsuccessful reclosure (final tripping), the automatic reclosure is blocked dy-
namically (see also margin heading „Reclose Block“, above).
The sequence above applies for single reclosure cycles. In 7SD5 multiple reclosure
(up to 8 cycles) is also possible (see below).
Multi-shot Reclos-
ing If a short-circuit still exists after a reclosure attempt, further reclosure attempts can be
made. Up to 8 reclosure attempts are possible with the automatic reclosure function
integrated in the 7SD5.
The first four reclosure cycles are independent of each other. Each one has separate
action and dead times, can operate single-or three-pole and can be blocked separate-
ly via binary inputs. The parameters and intervention possibilities of the fourth cycle
also apply to the fifth cycle and onwards.
The sequence is the same in principle as in the different reclosure programs described
above. However, if the first reclosure attempt was unsuccessful, the reclosure function
is not blocked, but instead the next reclose cycle is started. The appropriate dead time
starts with the reset of the trip command or opening of the circuit breaker (pole) (aux-
iliary contact criterion). The circuit breaker receives a new close command after expiry
of the dead time. At the same time the reclaim time is started.
Until the set maximum number of permissible auto-reclose cycles has been reached,
the reclaim time is reset with every new trip command after reclosure and started
again with the next close command.
If one of the reclosing attempts is successful, i.e. the fault disappeared after reclosure,
the blocking time expires and the automatic reclosing system is reset. The fault is
cleared.
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