Siemens 7VK512

-ETHOD OF OPERATION6+
6
#
' #

 3YNCHRONISM AND VOLTAGE CHECK
 'ENERAL
4HE SYNCHRONISM AND VOLTAGE CHECK FUNCTION WILL EN
SURE WHEN SWITCHING A LINE ONTO BUS
BARS THAT THE
STABILITY OF THE NETWORK WILL NOT BE ENDANGERED 4HE
FUNCTION CAN BE PROGRAMMED TO PERFORM THE SYN
CHRONISM AND VOLTAGE CHECK ONLY FOR AUTO
RECLOSE
ONLY FOR MANUAL CLOSE OR FOR BOTH CASES $IFFERENT
PERMISSION CRITERIA CAN ALSO BE PROGRAMMED FOR AU
TOMATIC CLOSE AND FOR MANUAL CLOSE
4HE SYNCHRONISM AND VOLTAGE CHECK ELEMENT USES
THE FEEDER VOLTAGE
DESIGNATED WITH 5 AND THE
BUS
BAR VOLTAGE DESIGNATED WITH 5 FOR COM
PARISON OF THE TWO VOLTAGES 4HESE VOLTAGES CAN BE
ANY CONVENIENT PHASE
TO EARTH OR PHASE TO
PHASE VOLTAGE BUT MUST BE THE SAME ON THE FEEDER
SIDE AND ON THE BUS
BAR SIDE
6+
0ROTECTION
!2
3YNC
"US BAR
&EEDER
,
$ISCREPANCY
SWITCH
) 5
5
42)0
#,/3%
&IGURE  3YNCHRO CHECK ON CLOSING
7HEN A POWER TRANSFORMER IS SITUATED BETWEEN THE
FEEDER VOLTAGE TRANSFORMER AND THE BUS
BAR VOLTAGE
TRANSFORMER &IGURE  ITS VECTOR GROUP CAN BE
MATCHED BY THE 6+ RELAY SO THAT NO EXTERNAL
MATCHING TRANSFORMERS ARE NECESSARY
"US BAR
) 5
5
6+
0ROTECTION
3YNC
,
$ISCREPANCY
SWITCH
42)0
#,/3%
&IGURE  3YNCHRO CHECK ACROSS TRANSFORMER
4HE SYNCHRONISM AND VOLTAGE CHECK FUNCTION IN
6+ NORMALLY OPERATES IN CONJUNCTION WITH THE IN
TEGRATED AUTO
RECLOSE AND MANUAL CLOSE FUNCTIONS
)T IS HOWEVER POSSIBLE TO OPERATE WITH AN EXTERNAL
AUTO
RECLOSE RELAY )N THIS CASE THE SIGNAL EX
CHANGE BETWEEN THE DEVICES MUST BE PERFORMED
THROUGH BINARY INPUTS AND OUTPUTS
&URTHERMORE SYNCHRONOUS OR ASYNCHRONOUS SWITCH
ING IS POSSIBLE 3YNCHRONOUS SWITCHING MEANS THAT
THE CLOSING COMMAND IS GIVEN AS SOON AS THE CRITICAL
VALUES VOLTAGE MAGNITUDE DIFFERENCE 5 ANGLE DIF
FERENCE  AND FREQUENCY DIFFERENCE F LIE WITHIN
THE SET TOLERANCES &OR ASYNCHRONOUS SWITCHING THE
DEVICE CALCULATES THE CORRECT TIMING OF THE CLOSING