6.3.1 电源S1(无穷大系统)提供的短路电流: Id1=
xIj3i-iii
?
1.56?17.485(kA)
0.089226.3.2 电源S2(有限电源S=100MVA)电源提供的短路电流: xjs?xii-iii?100100?1.7849??1.7849100100 查运算曲线得S2提供的短路电流标幺值为:
*Id2?0.584
由S2提供的短路电流有名值为: **Id2=Id2?Ie?Id2?6.3.3 总的短路电流 3?UeSe*?Id2?100?0.584?1.56?0.911(kA) 3?37ich1=2KchI?=2.55?18.40?46.92(kA)
I
?
?Id1?Id2?17.485?0.911?18.40(kA)
∴ 投产年对称短路计算结果如下:220kV侧三相短路电流28.49kA; 110kV侧三相短路电流14.40kA; 35kV侧三相短路电流18.40kA。
7. 单相短路电流计算:
7.1 d1点短路(220kV侧)
冲击电流:ich Kch-冲击系数,取1.8
7.1.1 仅考虑S1(无穷大系统)电源单独作用:
xB11?(xB31//)]?0.01425//[//[x012x02
20.0833?0.01425//[?0.0228]?0.0117
2x0?*?
*
*
x
1?*
?x2?*?x'
1?
?0.00892
0.08330.05?(//0.2546)]22Ij10.251 正序电流有名值:I'd(1)=(1)'??8.497(kA)
x*0.02954
(1)
x*'?x1?*?x2?*?x0?*?0.00892?0.00892?0.0117?0.02954
仅考虑S1作用时单相接地短路电流有名值:
(1)'Id?3I1d(1)?3?8.497?25.49(kA)
7.1.2 仅考虑S2(有限电源S=100MVA)电源单独作用:
xB31//)]?0.01425//[xx01//[2B11?(2x020.0833?0.01425//[?0.0228]?0.01172x0?*?**x1?*
?x2?*?x''
1?
?0.7624
0.08330.05?(//0.2546)]22 (1)x*''?x(1)xjs?x*''?1?*100100?1.5365??1.5365100100 ?x2?*?x0?*?0.7624?0.7624?0.0117?1.5365 查运算曲线得S2单独作用时的正序电流标幺值为
*'Id(1)?0.6815
正序电流有名值为 *'*'I''d(1)?Id?I?I(1)ed(1)?3?UeSe?0.6815?100?0.6815?0.251?0.171(kA) 3?230仅考虑S2作用时单相接地短路电流有名值:
(1)''Id2?3Id(1)?3?0.171?0.513(kA)
7.1.3 单相接地短路有名值:
(1)(1)(1)Id?Id1?Id2?25.49?0.51?26.00(kA)
7.1.4 单相接地短路电流冲击值:
ich1=2KchId(1)=2.55?26.00?66.30(kA)
7.2 d2点短路(110kV侧)
冲击电流:ich
Kch-冲击系数,取1.8
7.2.1 仅考虑S1(无穷大系统)电源单独作用:
x
1?*
?x2?*?x'
?x*
2?
?0.0367
*B3122?0.0559//0.025//0.2546?0.0162
x0?*?(x01
(1)'x*?x
B11)//x
0.08330.05)////0.2546 22//x02?(0.01425?
Ij20.502 正序电流有名值:I'd(1)=(1)'??5.60(kA)
x*0.0896
1?*
?x2?*?x0?*?0.0367?0.0367?0.0162?0.0896
仅考虑S1作用时单相接地短路电流有名值:
(1)'
Id1?3Id(1)?3?5.60?16.80(kA)
7.2.2 仅考虑S2(有限电源S=100MVA)电源单独作用:
x1?*
?x2?*?x''
22?0.0559//0.025//0.2546?0.0162x0?*?(x01?x2?
?0.7346
*B11)//x 0.08330.05)////0.2546 22*B31//x02?(0.01425?(1)x*''?x1?*?x2?*?x0?*?0.7346?0.7346?0.0162?1.4854 xjs?x*''?(1)100100?1.4854??1.4854100100 查运算曲线得S2单独作用时的正序电流标幺值为
*'
Id(1)?0.700
正序电流有名值为 *'*'I''d(1)?Id(1)?Ie?Id(1)?3?UeSe?0.700?100?0.700?0.502?0.35(kA) 3?115仅考虑S2作用时单相接地短路电流有名值:
(1)''Id2?3Id(1)?3?0.35?1.05(kA)
7.2.3 单相接地短路电流有名值:
(1)(1)(1)Id?Id1?Id2?16.80?1.05?17.85
7.2.4 单相接地短路电流冲击值:
ich1=2KchId(1)=2.55?17.85?45.52(kA)
8. 两相接地短路电流计算 8.1 d1点短路(220kV侧)
冲击电流:ich
Kch-冲击系数,取1.8 8.1 d1点短路(220kV侧)
冲击电流:ich
Kch-冲击系数,取1.8
8.1.1 仅考虑S1(无穷大系统)电源单独作用:
xB31//)]?0.01425//[xx01//[2B11?(2x02
0.0833?0.01425//[?0.0228]?0.0117
2x0?*?
*
*
x
1?*
?x2?*?x'
1?
?0.00892
0.08330.05?(//0.2546)]22
x
*
(1,1)'
?
x1?*?
Ij10.251 正序电流有名值:Id(1)=(1,1)??17.954(kA) 'x*0.01398
xxx?x2?*2?*
0?*0?*
?0.00892?
0.00892?0.0117?0.01398
0.00892?0.0117
仅考虑S1作用时两相接地短路电流有名值:
(1,1)
Id1?mId(1)
m?3?1?xx?x?x2?*2?*0?*0?*?2?3?1??0.00892?0.0117?0.00892?0.01172?1.5045
(1,1)Id1?mId(1)?1.5045?17.954?27.01(kA)
8.1.2 仅考虑S2(有限电源S=100MVA)电源单独作用:
xB31//)]?0.01425//[xx01//[2B11?(2x020.0833?0.01425//[?0.0228]?0.01172x0?*?**x1?*
?x2?*?x''
1?
?0.7624
0.08330.05?(//0.2546)]22 x*(1,1)''?x1?*?(1,1)xjs?x*''?100100?0.7739??0.7739100100 xxx?x2?*2?*0?*0?*?0.7624?0.7624?0.0117?0.77390.7624?0.0117 查运算曲线得S2单独作用时的正序电流标幺值为