Sel SEL-351A - Synchronism Check Elements Operation; Voltage Window; Other Uses for Voltage Window Elements; Block Synchronism Check Conditions

Date Code 20010307 Overcurrent, Voltage, Synchronism Check, and Frequency Elements 3-39
SEL-351A Instruction Manual
&KHFNZLWKWKH6(/5HOD\)DPLO\IRUPRUHLQIRUPDWLRQRQVHWWLQJ6<1&3ZLWKDQDQJOH
VHWWLQJ
Synchronism Check Elements Operation
5HIHUWR)LJXUHDQG)LJXUH
Voltage Window
5HIHUWR)LJXUH
6LQJOHSKDVHYROWDJHLQSXWV9
3
DQG9
6
DUHFRPSDUHGWRDYROWDJHZLQGRZWRYHULI\WKDWWKH
YROWDJHVDUH³KHDOWK\´DQGOLHZLWKLQVHWWDEOHYROWDJHOLPLWV9/2DQG9+,,IERWKYROWDJHV
DUHZLWKLQWKHYROWDJHZLQGRZWKHIROORZLQJ5HOD\:RUGELWVDVVHUW
93 LQGLFDWHVWKDWYROWDJH9
3
LVZLWKLQYROWDJHZLQGRZVHWWLQJOLPLWV9/2DQG9+,
96 LQGLFDWHVWKDWYROWDJH9
6
LVZLWKLQYROWDJHZLQGRZVHWWLQJOLPLWV9/2DQG9+,
$VGLVFXVVHGSUHYLRXVO\YROWDJH9
$
GHWHUPLQHVWKHIUHTXHQF\RQWKHYROWDJH9
3
VLGHRIWKH
FLUFXLWEUHDNHU9ROWDJH9
$
LVDOVRUXQWKURXJKYROWDJHOLPLWV9/2DQG9+,WRHQVXUH
³KHDOWK\YROWDJH´IRUIUHTXHQF\GHWHUPLQDWLRQZLWKFRUUHVSRQGLQJ5HOD\:RUGELWRXWSXW9$
Other Uses for Voltage Window Elements
,IYROWDJHOLPLWV9/2DQG9+,DUHDSSOLFDEOHWRRWKHUFRQWUROVFKHPHV5HOD\:RUGELWV
9396DQG9$FDQEHXVHGLQRWKHUORJLFDWWKHVDPHWLPHWKH\DUHXVHGLQWKH
V\QFKURQLVPFKHFNORJLF
,IV\QFKURQLVPFKHFNLVQRWEHLQJXVHG5HOD\:RUGELWV9396DQG9$FDQVWLOOEHXVHG
LQRWKHUORJLFZLWKYROWDJHOLPLWVHWWLQJV9/2DQG9+,VHWDVGHVLUHG(QDEOHWKH
V\QFKURQLVPFKHFNORJLFVHWWLQJ( <DQGPDNHVHWWLQJV9/2DQG9+,$SSO\5HOD\
:RUGELWV9396DQG9$LQWKHGHVLUHGORJLFVFKHPHXVLQJ6(/
2*,&FRQWUROHTXDWLRQV
(YHQWKRXJKV\QFKURQLVPFKHFNORJLFLVHQDEOHGWKHV\QFKURQLVPFKHFNORJLFRXWSXWV5HOD\
:RUGELWV6)$DQG$GRQRWQHHGWREHXVHG
Block Synchronism Check Conditions
5HIHUWR)LJXUH
7KHV\QFKURQLVPFKHFNHOHPHQWVOLSIUHTXHQF\FDOFXODWRUUXQVLIERWKYROWDJHV9
3
DQG9
6
DUH
KHDOWK\93DQG96DVVHUWHGWRORJLFDODQG
WKH6(/2*,&FRQWUROHTXDWLRQVHWWLQJ
%6<1&+%ORFN6\QFKURQLVP&KHFNLVGHDVVHUWHG ORJLFDO6HWWLQJ%6<1&+LVPRVW
FRPPRQO\VHWWREORFNV\QFKURQLVPFKHFNRSHUDWLRQZKHQWKHFLUFXLWEUHDNHULVFORVHG
V\QFKURQLVPFKHFNLVRQO\QHHGHGZKHQWKHFLUFXLWEUHDNHULVRSHQ
%6<1&+  $ VHH)LJXUH
,QDGGLWLRQV\QFKURQLVPFKHFNRSHUDWLRQFDQEHEORFNHGZKHQWKHUHOD\LVWULSSLQJ
%6<1&+  75,3