Cienfuegos 3 phase short circuit current
113.8kV busbarparallel operation Theoriginal data:
1.1 Calculation of per unit reactance
MVA j 100S =
033.0204
.3007100
1==
=
Sc
S X j
2555.063
100
1001.16100U d 32=⨯=⨯=
=e j S S X X ％
combine 40 generators to one
0476.040
15.3100
1006100U d 4=⨯⨯=⨯=
e j S S X ％ 1571.040
7.21001005.12100X '
'd 5=⨯⨯=⨯=e j S S X ％
1.2 d1 point three-phase short circuit(110kV)
29105.01157.00476.02555
.02555.02555
.02555.0||54326=+++⨯=
++=X X X X X ）（
1.2.1 short circuit supplied by SC
kA 214.15115
3100
330.01U 3X 1'j 1)3(1=⨯⨯=⨯=j d S I
1.2.2 short circuit supplied by GENERATOR
314.0100
40
7.229105.0X X 6=⨯⨯=⨯
=j N js S S According to the operational curve of Steam-turbine generator ='
'*I 3.5
kA 898.1115
340
7.25.3U 3''j ''*)3(1=⨯⨯⨯=⨯
=N d S I I 1.2.3 short circuit current in sum
kA 112.17898.1214.15''')3(1)3(1)3(1=+=+=d d d I I I
1.3 d2 point three-phase short circuit(13.8kV)
60751.0033.02555
.02555.02555
.02555.0||1327=++⨯=
+=X X X X ）（
1633.01157.00476.0548=+=+=X X X
1.3.1 short circuit supplied by SC
kA 77.245
.14310016075.01U 3X 1'j 7)3(1=⨯⨯=⨯=
j d S I 1.3.2 short circuit supplied by GENERATOR
176.0100
40
7.21633.0X X 8=⨯⨯=⨯
=j N js S S According to the operational curve of Steam-turbine generator ='
'*I 6.2
kA 662.265
.14340
7.22.6U 3''j ''*)3(1=⨯⨯⨯=⨯
=N d S I I 1.3.3 short circuit current in sum
kA 432.51662.2677.24''')3(1)3(1)3(1=+=+=d d d I I I
213.8kV busbar splitting operation The original data:
2.1 Calculation of per unit reactance
MVA j 100S =
033.0204
.3007100
1==
=
Sc
S X j
2555.063
100
1001.16100U d 32=⨯=⨯=
=e j S S X X ％ combineG1 and G24 generators to one
0794.024
15.3100
1006100U d 4=⨯⨯=⨯=
e j S S X ％
9291.024
7.21001005.12100X '
'd 5=⨯⨯=⨯=e j S S X ％
combineG25 and G40 generators to one
119.016
15.31001006100U d 6=⨯⨯=⨯=e j S S X ％
8932.016
7.21001005.12100X '
'd 7=⨯⨯=⨯=e j S S X ％
2.2 d1 point three-phase short circuit(110kV)
2785.01929.00794.02555.05428=++=++=X X X X 6386.08932.0191.02555.07629=++=++=X X X X
2.2.1 short circuit supplied by SC
kA 214.15115
3100330.01U 3X 1'j 1)3(1=⨯⨯=⨯=
j d S I 2.2.2 short circuit supplied by GENERATOR1
342.0100
24
7.25278.0X X 81=⨯⨯=⨯
=j N js S S According to the operational curve of Steam-turbine generator ='
'*I 3.2
kA 041.1115
324
7.22.3U 3''j ''*)3(1=⨯⨯⨯=⨯
=N d S I I 2.2.3 short circuit supplied by GENERATOR2
287.0100
167.26638.0X X 9=⨯⨯=⨯
=j N js S S According to the operational curve of Steam-turbine generator ='
'*I 3.8
kA 824.0115
316
7.28.3U 3'''j ''*)3(1=⨯⨯⨯=⨯
=N d S I I 2.2.4 short circuit current in sum
kA 079.17824.0041.1214.15'''''')3(1)3(1)3(1)3(1=++=++=d d d d I I I I
2.3 d2 point three-phase short circuit(1
3.8kV)
2723.01929.00794.05410=+=+=X X X
0123.06638.0033
.02555.02555.0033.0 ||/]X ||[9212191291111=⨯++=+
+=+=X X X X X X X X X X X ）（）（0587.6033
.06638
.02555.02555.06386.0 ||/]X ||[1292991291912=⨯++=+
+=+=X X X X X X X X X X X ）（）（
2.3.1 short circuit supplied by SC
kA 22.135
.143100
0123.01U 3X 1'j 11)3(1=⨯⨯=⨯=j d S I
2.3.2 short circuit supplied by GENERATOR1
17645.0100
247.27232.0X X 10=⨯⨯=⨯
=j N js S S According to the operational curve of Steam-turbine generator ='
'*I 6.2
kA 00.165
.14324
7.22.6U 3''j ''*)3(1=⨯⨯⨯=⨯
=N d S I I 2.3.3 short circuit supplied by GENERATOR2
617.2100
167.20587.6X X 12=⨯⨯=⨯
=j N js S S According to the operational curve of Steam-turbine generator ='
'*I 0.37
kA 636.05
.14316
7.237.0U 3'''j ''*)3(1=⨯⨯⨯=⨯
=N d S I I 2.3.4 short circuit current in sum
kA 856.29636.000.1622.13'''''')3(1)3(1)3(1)3(1=++=++=d d d d I I I I
3 conclusion
economical efficiency, We commend splitting operation as the normal way of running.
Appendix 1 the operational curve of Steam-turbine generator。