3-44
Overcurrent, Voltage, Synchronism Check, Frequency, and Power Elements
Date Code 20010307
SEL-351-0, -1, -2, -3, -4 Instruction Manual
,QDGGLWLRQV\QFKURQLVPFKHFNRSHUDWLRQFDQEHEORFNHGZKHQWKHUHOD\LVWULSSLQJ
%6<1&+ 75,3
Slip Frequency Calculator
5HIHUWR)LJXUH
7KHV\QFKURQLVPFKHFNHOHPHQW6OLS)UHTXHQF\&DOFXODWRULQ)LJXUHUXQVLIYROWDJHV9
3
9
6
DQG9
$
RU9
$%
IRUGHOWDDUHKHDOWK\9396DQG9$DVVHUWHGWRORJLFDODQGWKH
6(/
2*,&
FRQWUROHTXDWLRQVHWWLQJ%6<1&+%ORFN6\QFKURQLVP&KHFNLVGHDVVHUWHG
ORJLFDO7KH6OLS)UHTXHQF\&DOFXODWRURXWSXWLV
6OLS)UHTXHQF\ I
3
I
6
LQ] VOLSF\FOHVVHFRQG
I
3
IUHTXHQF\RIYROWDJH9
3
LQ] F\FOHVVHFRQG
>GHWHUPLQHGIURP9
$
RU9
$%
IRUGHOWD@
I
6
IUHTXHQF\RIYROWDJH9
6
LQ] F\FOHVVHFRQG
$FRPSOHWHVOLSF\FOHLVRQHVLQJOHUHYROXWLRQRIRQHYROWDJHHJ9
6
E\DQRWKHUYROWDJH
HJ9
3
%RWKYROWDJHVDUHWKRXJKWRIDVUHYROYLQJSKDVRUZLVHVRWKH³VOLSSLQJ´RI9
6
SDVW9
3
LVWKHUHODWLYHUHYROYLQJRI9
6
SDVW9
3
)RUH[DPSOHLQ)LJXUHLIYROWDJH9
3
KDVDIUHTXHQF\RI+]DQGYROWDJH9
6
KDVD
IUHTXHQF\RI+]WKHGLIIHUHQFHEHWZHHQWKHPLVWKHVOLSIUHTXHQF\
6OLS)UHTXHQF\ +]+] +] VOLSF\FOHVVHFRQG
7KHVOLSIUHTXHQF\LQWKLVH[DPSOHLVQHJDWLYHLQGLFDWLQJWKDWYROWDJH9
6
LVQRW³VOLSSLQJ´EHKLQG
YROWDJH9
3
EXWLQIDFW³VOLSSLQJ´DKHDGRIYROWDJH9
3
,QDWLPHSHULRGRIRQHVHFRQGWKHDQJXODU
GLVWDQFHEHWZHHQYROWDJH9
3
DQGYROWDJH9
6
FKDQJHVE\VOLSF\FOHVZKLFKWUDQVODWHVLQWR
VOLSF\FOHVVHFRQG[VOLSF\FOH[VHFRQG
7KXVLQDWLPHSHULRGRIRQHVHFRQGWKHDQJXODUGLVWDQFHEHWZHHQYROWDJH9
3
DQGYROWDJH9
6
FKDQJHVE\
7KHDEVROXWHYDOXHRIWKH6OLS)UHTXHQF\RXWSXWLVUXQWKURXJKDFRPSDUDWRUDQGLIWKHVOLS
IUHTXHQF\LVOHVVWKDQWKHPD[LPXPVOLSIUHTXHQF\VHWWLQJ6)5HOD\:RUGELW6)DVVHUWVWR
ORJLFDO
Angle Difference Calculator
7KHV\QFKURQLVPFKHFNHOHPHQW$QJOH'LIIHUHQFH&DOFXODWRULQ)LJXUHUXQVLIWKHVOLS
IUHTXHQF\LVOHVVWKDQWKHPD[LPXPVOLSIUHTXHQF\VHWWLQJ6)5HOD\:RUGELW6)LVDVVHUWHG
Voltages V
P
and V
S
are “Static”
5HIHUWRWRSRI)LJXUH
