Siemens 7VK512

-ETHOD OF OPERATION6+
6

#
' #
 4REATMENT OF EVOLVING FAULTS FOR
SINGLE POLE AUTO RECLOSURE
7HEN SINGLE POLE OR SINGLE AND THREE POLE
AUTO
RECLOSURES ARE CARRIED OUT IN THE NETWORK SPE
CIAL ATTENTION HAS TO BE DIRECTED TO EVOLVING FAULTS
%VOLVING FAULTS ARE HERE DEFINED AS THOSE WHICH AFTER
CLEARANCE OF THE FIRST
DETECTED FAULT OCCUR DURING
THE DEAD TIME OF AN !2 CYCLE
4HE EVOLVING FAULT IS DETECTED BY THE FEEDER PROTEC
TION )T INFORMS THE !2 FUNCTION BY OUTPUTTING THE FAULT
DETECTION AND TRIP SIGNALS THROUGH BINARY INPUTS 4HE
CRITERION FOR RECOGNITION OF EVOLVING FAULTS CAN BE SE
LECTED IN 6+ TO BE EITHER 42)0 #/--!.$ DUR
ING THE DEAD TIME OR ANY FURTHER &!5,4 $%4%#TION
FROM THE FEEDER PROTECTION
4HE REACTION OF THE !2
FUNCTION TO A RECOGNIZED
EVOLVING FAULT CAN ALSO BE SELECTED
A ./ SPECIAL REACTION TO EVOLVING FAULTS
!S SOON AS AN EVOLVING FAULT HAS BEEN DETECTED
THE UNIT SWITCHES TO THE THREE
POLE AUTO RECLO
SURE CYCLE %VERY TRIP WILL BE THREE
POLE )F THREE
POLE AUTO RECLOSURE IS PERMITTED THEN THE DEAD
TIME FOR THREE
POLE AUTO RECLOSURE BEGINS SI
MULTANEOUSLY WITH THE INTERRUPTION OF THE EVOLVING
FAULT 7HEN THE DEAD TIME HAS EXPIRED THE CIRCUIT
BREAKER RECEIVES THE COMMAND TO CLOSE 4HE FUR
THER SEQUENCE IS THE SAME AS FOR SINGLE
AND
THREE
POLE AUTO RECLOSURE
4HE TOTAL DEAD TIME IN THIS CASE CONSISTS OF THE
DEAD TIME FOR THE SINGLE
POLE AUTO RECLOSURE
WHICH HAS EXPIRED WHEN THE EVOLVING FAULT IS INTER
RUPTED PLUS THE DEAD TIME FOR THE THREE
POLE
AUTO
RECLOSURE 4HIS IS USEFUL BECAUSE ONLY THE
DEAD TIME FOR THREE
POLE AUTO RECLOSURE IS OF IM
PORTANCE FOR THE STABILITY OF THE NETWORK
B "LOCKING OF RECLOSURE AFTER EVOLVING FAULTS !,
7!93
!S SOON AS AN EVOLVING FAULT HAS BEEN DETECTED
RECLOSURE IS BLOCKED %VERY TRIP WILL BE THREE
POLE
REGARDLESS WHETHER THREE
POLE !2 IS PERMITTED OR
NOT
C "LOCKING AFTER EVOLVING FAULTS AFTER AN ADJUSTABLE
DISCRIMINATION TIME 4
$)3#2
4HE DISCRIMINATION TIME STARTS SIMULTANEOUSLY
WITH THE SINGLE
POLE DEAD TIME )T IS USED TO DIS
CRIMINATE FROM WHICH POINT IN TIME AN EVOLVING
FAULT IS IDENTIFIED AS SUCH )F THE EVOLVING FAULT OC
CURS BEFORE THE EXPIRY OF THE DISCRIMINATION TIME
THE DEVICE IS SWITCHED TO A THREE
POLE !2 CYCLE
IF PERMITTED AS UNDER A )F HOWEVER THE EVOLVING
FAULT OCCURS AFTER THE DISCRIMINATION TIME HAS EX
PIRED RECLOSURE IS BLOCKED AS UNDER B
 -ULTI SHOT AUTO RECLOSURE
4HE AUTO RECLOSE FUNCTION OF 6+ WILL ALSO PER
MIT MULTI
SHOT RECLOSURE UP TO  CONSECUTIVE $!2
CYCLES 4HE SECOND AND EACH FURTHER CYCLE ARE AL
WAYS THREE
POLE 4HE $!2 FUNCTION OF 6+ IN
FORMS THE FEEDER PROTECTION ABOUT READINESS FOR RE
CLOSURE BY ITS OUTPUT SIGNAL
$!2 :ONE 2EL  4HE
SEPARATELY SET ACTION TIME REFER TO 3ECTION  OF
THE $!2 FUNCTION IS STARTED WITH THE FAULT DETECTION
SIGNAL OF THE FEEDER PROTECTION VIA THE BINARY INPUT
3TART !2 
$IFFERENT NUMBERS OF $!2 CYCLES CAN BE SET FOR SING
LE
PHASE FAULTS AND MULTI PHASE FAULT TRIPPING
COMMAND IS NEVERTHELESS ALWAYS THREE
POLE 4HE
SET NUMBER OF $!2 CYCLES DOES NOT INCLUDE THE FIRST
2!2 CYCLE
$EAD TIMES CAN BE INDIVIDUALLY SET FOR THE FIRST THREE
!2 CYCLES FURTHER CYCLES OPERATE WITH THE DEAD TIME
OF THE THIRD CYCLE )N THIS CASE ALL !2 CYCLES ARE DECI
SIVE IE ALSO THE 2!2 CYCLE 4HE 2!2 CYCLE OPERATES
WITH ITS DEAD TIME 2!2 4
0/, FOR SINGLE OR 2!2
4
0/, FOR THREE POLE 2!2 THE FIRST $!2 IS THE
SECOND CYCLE WITH THE DEAD TIME FOR THE SECOND
CYCLE $!2 40/, ETC )F NO 2!2 CYCLE HAS OC
CURRED EG 2!2 BLOCKED THEN THE FIRST $!2 CYCLE
OPERATES WITH THE DEAD TIME FOR THE FIRST CYCLE $!2
40/, ETC
%ACH NEW PICK
UP RESTARTS THE ACTION TIME
$!2 4
!#4 WITHIN WHICH A TRIPPING COMMAND MUST
OCCUR !FTER FAULT CLEARANCE WITHIN THE ACTION TIME THE
DEAD TIME BEGINS !T THE END OF THIS THE CIRCUIT
BREAKER IS GIVEN A NEW CLOSING COMMAND 3IMULTA
NEOUSLY THE RECLAIM TIME 4
2%#,!)- 3ECTION
 IS STARTED
)F ONE OF THE CYCLES IS SUCCESSFUL THAT IS AFTER RECLOSE
THE FAULT IS NO LONGER PRESENT THE RECLAIM TIME 4
2%#,!)- 3ECTION  RUNS OUT AND ALL FUNCTIONS
OF 6+ RETURN TO THE QUIESCENT CONDITION 4HE NET
WORK FAULT IS CLEARED THE !2 FUNCTIONS ARE READY FOR A
NEW FAULT
!S LONG AS THE PERMITTED NUMBER OF CYCLES HAS NOT
BEEN REACHED THE RECLAIM TIME IS RESET BY EACH NEW
TRIP COMMAND AND RECOMMENCES WITH THE NEXT CLOS
ING COMMAND
)F NONE OF THE !2
CYCLES HAVE BEEN SUCCESSFUL THEN
THE SHORT
CIRCUIT PROTECTION CARRIES OUT A FINAL DIS
CONNECTION AFTER THE LAST PERMISSIBLE CYCLE 4HE
LOCK
OUT TIME 4",/#+ $9. 3ECTION  IS
STARTED &OR THIS TIME ANY CLOSE COMMAND FROM
6+ IS LOCKED
4HE SUBSEQUENT CYCLES $!2 CAN BE BLOCKED BY A
BINARY INPUT INDEPENDENTLY OF THE FUNCTION OF THE
2!2 CYCLE