2.13 Automatic reclosure function (optional)
247
7SA522 Manual
C53000-G1176-C155-3
breaker was detected, no reclosure takes place and a final three-pole trip command
is issued. If this is not desired, set address to 0.
The options for handling evolving faults are described in Subsection 2.13 under
margin heading “Handling Evolving Faults”. The treatment of sequential faults is not
necessary on line ends where the adaptive dead time is applied (address $XWR
5HFORVH = $'7). The addresses and are then of no consequence and
therefore not accessible.
The detection of an evolving fault can be defined under address (9)/7
5(&2*.(9)/75(&2* ZLWK3,&.83 means that, during a dead time, every
pickup of a protective function will be interpreted as an evolving fault. With (9)/7
5(&2* ZLWK75,3 a fault during a dead time is only interpreted as a evolving fault
if it has led to a trip command by a protection function. This may also include trip com-
mands which are coupled in externally via a binary input or which have been transmit-
ted from an opposite end of the protected object. If an external protection device op-
erates together with the auto-reclosure, evolving fault detection with pickup
presupposes that a pickup signal of the external device is also connected to the
7SA522; otherwise an evolving fault can only be detected with the external trip
command even if ZLWK3,&.83 was set here.
The reaction in response to sequential faults can be selected under address .
(9)/702'( EORFNV$5 means that no reclosure takes place after detection of
a sequential fault. This is always useful when only single-pole reclosure is to take
place or when stability problems are expected due to the subsequent three-pole dead
time. If a three-pole reclose cycle is to be initiated by tripping of the evolving fault, set
(9)/702'( = VWDUWVS$5. In this case a separately adjustable three-pole
dead time is started with the three-pole trip command due to the sequential fault. This
is only useful if three-pole reclosure is also permitted.
Address 76WDUW021,725 monitors the reaction of the circuit-breaker after a
trip command. If the CB has not opened during this time (from the beginning of the trip
command), the automatic reclosure is blocked dynamically. The criterion for circuit
breaker opening is the position of the circuit breaker auxiliary contact or the disappear-
ance of the trip command. If a circuit-breaker failure protection (internal or external) is
used on the feeder, this time should be shorter than the delay time of the circuit-
breaker failure protection so that no reclosure takes place if the circuit-breaker fails.
If the reclosure command is transmitted to the opposite end, this transmission can be
delayed by the time setting in address 75HPRWH&ORVH. This transmission is
only posible if the device operates with adaptive dead time at the remote end
(address
$XWR5HFORVH = $'7). This parameter is otherwise irrelevant. On the one hand,
this delay serves to prevent the remote end device from reclosing unnecessarily when
local reclosure is unsuccessful. On the other hand it should be noted that the line is
not available for energy transport until the remote end has also closed. This delay
must therefore be added to the dead time for consideration of the network stability.
Configuration of
Au t o-r eclo sur e
This configuration concerns the interaction between the protection and supplementary
functions of the device and the automatic reclosure function. The selection of functions
of the device which are to start the automatic reclosure circuit and which are not to, is
made here.
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