Siemens siprotec 7SD5 User Manual page 303

The detection of an evolving fault can be defined under address 3406 EV. FLT.
RECOG.. EV. FLT. RECOG. with PICKUP means that, during a dead time, every
pickup of a protective function will be interpreted as an evolving fault. With EV. FLT.
RECOG. with TRIP a fault during a dead time is only interpreted as an 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 from external via a binary input or which have been trans-
mitted from an opposite end of the protected object. If an external protection device
operates together with the auto-reclosure, evolving fault detection with pickup presup-
poses that a pickup signal from the external device is also connected to the 7SD5; oth-
erwise an evolving fault can only be detected with the external trip command even if
with PICKUP was set here.
The reaction in response to sequential faults can be selected under address 3407.
EV. FLT. MODE Stops AutoRecl means that no reclosure takes place after de-
tection 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 EV. FLT. MODE = starts 3p AR. 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 3408 T-Start MONITOR 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 3410 T RemoteClose. This transmission is
only possible if the device operates with adaptive dead time at the remote end (ad-
dress 133 Auto Reclose = ADT). 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 sta-
bility.
Configuration of This configuration concerns the interaction between the protection and supplementary
Auto-Reclosure functions of the device and the auto reclose function. The selection of device functions
which are to start the automatic reclosure circuit and which are not to, is made here.
For the functions which are to start the auto-reclosure function, the corresponding
address is set to YES, for the others to NO. The other functions cannot start the auto-
matic reclosure because reclosure is of little use here.
7SD5 Manual
C53000-G1176-C169-1
Address 3420 AR WITH DIFF, i.e. with differential protection
Address 3421 AR w/ SOTF-O/C, i.e. with high-current switch-onto-fault function
Address 3422 AR w/ DIST., i.e. with distance protection
Address 3423 AR WITH I.TRIP, i.e. with permissive underreach transfer trip (PUTT)
Address 3424 AR w/ DTT, i.e. with direct transfer trip
Address 3425 AR w/ BackUpO/C, i.e. with time overcurrent protection
Address 3426 AR w/ W/I, with weak–infeed trip function
Address 3427 AR w/ EF-O/C, i.e. with earth fault protection for earthed systems
2.15 Automatic Reclosure Function (optional)
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