南华大学电气工程及其自动化专业课程设计
流过断路器1、2、3、4、5和6的短路电流为： If(2)=If(2)*IB=1.429×0.502=0.7163KA
(3)最大运行方式两相短路零序短路电流,如图3.2.2示
图3.2.2短路等值电路
XBL(0) =XL1(0)×XTB(0)/(XL1(0))+XTB(0))=0.4536×0.2401/(0.4536+0.2401)=0.157 XTL(0) =(XL4(0)+XT8(0))×XTC(0)/(XL4(0)+XT8(0)+XTC(0))=0.188 XLB(0) =(XL2(0)+XBL(0))×XTL(0)/(XL2(0)+XTBL(0)+XTC(0))=0.138 Xff2(0) =(XL3(0)+XT(0))×XLB(0)/(XL3(0)+XT(0))+XLB(0))=0.1208 Iff2(0)*=E(0)/Xff2(0)=1.05/0.1208=8.692 Iff2(0)=Iff2(0)*IB=8.692×0.502=4.3634KA
3.2.3 d3发生短路时流过断路2
(1)最大运行方式正序短路电流 Xff3=XdT+XL=0.18255+0.5444=0.72695 Id3·max*=E/Xff3=1.05/0.72695≈1.4444 Id3·max=Id3·max*IB=1.4444×0.502≈0.725KA (2)最小运行方式两相短路正序短路电流
Xff3=Xd1+XT1＋XL=0.4224+0.3050+0.5444=0.9996 If(2)*=1.732E/2Xff1=1.732×1.05/2×0.9996=0.9097 If(2)=If(2)*IB=0.9097×0.502=0.4567KA
(3)最大运行方式两相短路零序短路电流,如图3.2.3示
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南华大学电气工程及其自动化专业课程设计
图3.2.3短路等值电路
XTL4(0)=(XL4(0) +XT8)×(XL3(0) +XT)/(XL4(0) +XT8+XL3(0) +XT)
=(0.2268+0.6405)×(0.8166+0.0781)/(0.2268+0.6405+0.8166+0.0781) =0.4404
XTL2(0) =(XL2(0)+XTC)×XTB/(XL2(0)+XTC+XTB)
=(0.363+0.2401)×0.2401/(0.363+0.2401+0.2401) =0.1717
XBL(0) =XTL4(0)×XTL2(0)/(XTL4(0)+XTL2(0))=0.4404×0.1717/(0.4404+0.1717) =0.1235
Xff3(0)=XL1(0)+XBL(0)=0.4536＋0.1235=0.5771 Iff3(0)*=E(0)/Xff3(0)=1.05/0.5771=1.819 Iff3(0)=Iff3(0)*IB=1.89×0.502=0.913KA
3.2.4 d4点发生短路时流过断路1
(1)最大运行方式正序短路电流
Xff4=XdT+XL1=0.18255+0.1512=0.33375 Id4·max*=E/Xff4=1.05/0.33375≈3.146 Id4·max=Id4·max*IB=3.146×0.502≈1.579KA (2)最小运行方式短路正序短路电流 X3 =(XL3+XL2)×XL1/( XL1+XL2+ XL3)
=(0.2722+0.121)×0.1512/(0.2722+0.121+ 0.1512) =0.1156
Xff2=Xd1+X3=0.18255+0.1156=0.2981 If(3)*= E/Xff1=1.05/0.2981=3.522 If(3)=If(3)*IB=3.522×0.502=1.768KA
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南华大学电气工程及其自动化专业课程设计
流过断路器1、4、5的三相短路电流为： If(3)1= If(3)×XL1/( XL1+XL2+ XL3)
=1.768×0.1512/(0.2722+0.121+ 0.1512) =0.491KA
流过断路器2、3的三相短路电流为： If2(3)=If(2)*－If1(2)= 1.768KA-0.491KA=1.277KA If(2)*=1.732E/2Xff1=1.732×1.05/2×0.2981=3.0496 If(2)=If(2)*IB=3.0496×0.502=1.531KA If(2)1*= If(2)*×XL1/( XL1+XL2+ XL3)
=3.0496×0.1512/(0.2722+0.121+ 0.1512) =0.847
流过断路器1、4、5的短路电流为： If1(2)=If(2)*IB=0.847×0.502=0.425KA 流过断路器2、3的短路电流为：
If2(2)=If(2)*－If1(2)= 1.531KA-0.425KA=1.106KA (3)最大运行方式两相短路零序短路电流
图3.2.4短路等值电路
X2(0) =(XL4(0)+XT8)×XTC/(XL4(0)+XT8+XTC)
=(0.8166+0.6405)×0.2401/(0.8166+0.6405+0.2401) =0.2061
X1(0) =(XL1(0)+XT)×XTB/(XL1(0)+XT+XTB)
=(0.4536+0.0781)×0.2401/(0.4536+0.0781+0.2401) =0.1654
Xff4(0) =X1(0)×(X2(0)+XL2(0))/(X1(0)+XL2(0)+X2(0))
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南华大学电气工程及其自动化专业课程设计
=0.1654×(0.2061+0.363)/(0.1654+0.2061+0.363) =0.1282
Iff4(0)*=E(0)/Xff4(0)=1.05/0.1282=8.193 Iff4(0)=Iff4(0)*IB=8.193×0.502=4.113KA
3.2.5 d4点发生短路时流过断路器2
(1)最大运行方式正序短路电流
其中：Xff5=XdT+XL3+XL2=0.18255+0.2722+0.121=0.57575
Id5·max*=E/Xff5=1.05/0.57575≈1.824 Id5·max=Id5·max*IB=1.824×0.502≈0.9155KA (2)最小运行方式短路正序短路电流 X3 =(XL3+XL2)×XL1/( XL1+XL2+ XL3)
=(0.2722+0.121)×0.1512/(0.2722+0.121+ 0.1512) =0.1156
Xff2=Xd1+X3=0.18255+0.1156=0.2981 If(3)*= E/Xff1=1.05/0.2981=3.522 If(3)=If(3)*IB=3.522×0.502=1.768KA 流过断路器1、4、5的三相短路电流为： If(3)1= If(3)×XL1/( XL1+XL2+ XL3)
=1.768×0.1512/(0.2722+0.121+ 0.1512) =0.491KA
流过断路器2、3的三相短路电流为： If2(3)=If(2)*－If1(2)= 1.768KA-0.491KA=1.277KA If(2)*=1.732E/2Xff1=1.732×1.05/2×0.2981=3.0496 If(2)=If(2)*IB=3.0496×0.502=1.531KA If(2)1*= If(2)*×XL1/( XL1+XL2+ XL3)
=3.0496×0.1512/(0.2722+0.121+ 0.1512) =0.847
流过断路器1、4、5的短路电流为： If1(2)=If(2)*IB=0.847×0.502=0.425KA
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南华大学电气工程及其自动化专业课程设计
流过断路器2、3的短路电流为：
If2(2)=If(2)*－If1(2)= 1.531KA-0.425KA=1.106KA (3)最大运行方式两相短路零序短路电流
图3.2.5短路等值电路
X50(0) =(XL4(0) +XT8)×(XL3(0) +XT)/(XL4(0) +XT8+XL3(0) +XT)
=(0.2268+0.6405)×(0.8166+0.0781)/(0.2268+0.6405+0.8166+0.0781) =0.4404
X32(0) =X50(0)×XTC /(X50(0)+XTC)=0.4404×0.2401/(0.4404+0.2401) =0.1554 Xff5(0) =(XL2(0)+ X32(0))×XTB/( XL2(0)+ X32(0)+XTB)=0.1641 Iff5(0)*=E(0)/Xff5(0)=1.05/0.1641=6.399 Iff5(0)=Iff5(0)*IB=6.399×0.502=3.212KA
3.2.6 d5点发生短路时流过断路器1
(1)最大运行方式正序短路电流
其中：Xff6=XdT+XL1+XL2=0.18255+0.1512+0.121=0.45475
Id6·max*=E/Xff6=1.05/0.45475≈2.309 Id6·max=Id6·max*IB=2.309×0.502≈1.159KA (2)最小运行方式短路正序短路电流
X2 =(XL1+XL2)×XL3/( XL1+XL2+ XL3)= XL3/2=0.1361 Xff6=Xd1+X2=0.18255+0.1361=0.31865 If(3)*= E/2Xff1=1.05/2×0.31865=1.648
流过断路器1、2、3、4、5和6的三相短路电流为： If(3)=If(3)*IB=1.648×0.502=0.827KA
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