-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
