短路计算 欧姆法计算书

欧姆法计算书 计算依据 《工厂与民用配电设计手册》第四章p90,p91,p99,p114,p116,p120页的公式 已知条件 元件1--高压系统: 高压侧系统短路容量Ss=200.000MVA 电阻R1=0.0995*160/S"=0.0995*160/200.000MVA=0.079mΩ 电抗X1=0.995*160/S"=0.995*160/200.000MVA=0.792mΩ 相保电阻Rφp1 =2R1/3=2*0.079mΩ/3=0.053mΩ 相保电抗Xφp1 =2X1 /3=2*0.792mΩ/3=0.528mΩ 元件2--高压线路: 线路长度L=1.000km 平均额定电压Un=10.500kV 线路每公里电阻R0=0.236Ω/km 线路每公里电抗X0=0.225Ω/km 电阻R2 =1000*R0 L*0.42 /Un2=1000*0.236Ω/km*1.000km*0.42 /10.500kV2=0.342mΩ 电抗X2 =1000*R0 L*0.42 /Un2=1000*0.225Ω/km*1.000km*0.42 /10.500kV2 =0.327mΩ 相保电阻Rφp2 =2R2/3=2*0.342mΩ/3=0.228mΩ 相保电抗Xφp2 =2X2/3=2*0.327mΩ/3=0.218mΩ 元件3--变压器: 额定电压Ur=10.5kV 额定容量Sr=2000KVA 短路电压Ud%=6 变压器短路损耗ΔP=14 零序电阻R0 =0.560 零序电抗X0 =4.767 电阻R3 =106*ΔP(Ur/Sr)2 *(0.42 /Ur2 )=14kW*(10.5kV/2000kVA)2 *(0.42 /Ur2 )*106=0.560mΩ阻抗Z3=104*Ud%Ur2/(100Sr)*(0.42/Ur2)=6*10.5kV2/(100*2000kVA)*(0.42/Ur2)*104 =4.80000 电抗X3 =(Z32 -R32 )0.5 =(4.800002 -0.5602 )0.5 =4.767 相保电阻Rφp3 =R3=0.560mΩ 相保电抗Xφp3 =X3=4.767mΩ 元件4--低压母线: 母线长度L=10.000m 母线单位长度电阻值R0=0.014mΩ/m 母线单位长度电抗值X0=0.147mΩ/m 母线单位长度相保电阻Rφp0=0.054mΩ/m 母线单位长度相保电抗Xφp0=0.340mΩ/m 电阻R4 =R0L=0.014mΩ/m*10.000m=0.140mΩ 电抗X4 =X0L=0.147mΩ/m*10.000m=1.470mΩ 相保电阻Rφp4=Rφp0L=0.054mΩ/m*10.000m=0.540mΩ 相保电抗Xφp4=Xφp0L=0.340mΩ/m*10.000m=3.400mΩ 元件5--低压线路: 线路长度L=0.100m 线路单位长度电阻值R0=0.146mΩ/m 线路单位长度电抗值X0=0.076mΩ/m 线路单位长度相保电阻Rφp0=0.596mΩ/m 线路单位长度相保电抗Xφp0=0.152mΩ/m 电阻R5 =R0L=0.146mΩ*0.100m=0.015mΩ 电抗X5 =X0L=0.076mΩ*0.100m=0.008mΩ 相保电阻Rφp5=Rφp0L=0.596mΩ*0.100m=0.060mΩ 相保电抗Xφp5=Xφp0L=0.152mΩ*0.100m=0.015mΩ 计算公式和过程 短路点1 冲击系数Kc=1.8 电阻Rs=R1=0.07900mΩ 电抗Xs=X1=0.79200mΩ 相保电阻Rφp=Rφp1=0.05300mΩ 相保电抗Xφp=Xφp1=0.52800mΩ 短路电流总阻抗Zk=(Rs2 +Xs2 )0.5 =(0.079002 +0.792002 )0.5=0.79593mΩ 相保阻抗Zφp=(Rφp2+Xφp2 )0.5 =(0.053002 +0.528002 )0.5 =0.53065mΩ 三相短路电流I"=230/Zk=230/0.79593=289.42580kA 单相接地故障电流Id=220/Zkφp =220/0.53065=413.43957kA 短路冲击电流ich=1.414KcId=1.414*1.8*289.42580=736.75780kA 短路全电流最大有效值Ich=[1+2(Kch-1)2 ]0.5 Id=[1+2(1.8-1)2 ]0.5 *289.42580=437.02337kA 短路点2 冲击系数Kc=1.8 电阻Rs=R1 +R2 =0.079+0.342=0.42100mΩ 电抗Xs=X1 +X2=0.792+0.327=1.11900mΩ 相保电阻Rφp=Rφp1+Rφp2=0.053+0.228=0.28100mΩ 相保电抗Xφp=Xφp1+Xφp2=0.528+0.218=0.74600mΩ 短路电流总阻抗Zk=(Rs2 +Xs2 )0.5 =(0.421002 +1.119002 )0.5=1.19558mΩ 相保阻抗Zφp=(Rφp2+Xφp2 )0.5 =(0.281002 +0.746002 )0.5=0.79717mΩ 三相短路电流I"=230/Zk=230/1.19558=192.67931kA 单相接地故障电流Id=220/Zkφp =220/0.79717=275.21560kA 短路冲击电流ich=1.414KcId=1.414*1.8*192.67931=490.48145kA 短路全电流最大有效值Ich=[1+2(Kch-1)2 ]0.5 Id=[1+2(1.8-1)2 ]0.5 *192.67931=290.93938kA 短路点3 冲击系数Kc=1.8 电阻Rs=R1 +R2 +R3=0.079+0.342+0.560=0.98100mΩ 电抗Xs=X1 +X2 +X3=0.792+0.327+4.767=5.88600mΩ 相保电阻Rφp=Rφp1+Rφp2+Rφp3=0.053+0.228+0.560=0.84100mΩ 相保电抗Xφp=Xφp1+Xφp2+Xφp3=0.528+0.218+4.767=5.51300mΩ 短路电流总阻抗Zk=(Rs2 +Xs2 )0.5 =(0.981002 +5.886002 )0.5 =5.96719mΩ 相保阻抗Zφp=(Rφp2+Xφp2 )0.5 =(0.841002 +5.513002 )0.5=5.57678mΩ 三相短路电流I"=230/Zk=230/5.96719=38.60490kA 单相接地故障电流Id=220/Zkφp =220/5.57678=39.34048kA 短路冲击电流ich=1.414KcId=1.414*1.8*38.60490=98.27203kA 短路全电流最大有效值Ich=[1+2(Kch-1)2 ]0.5 Id=[1+2(1.8-1)2 ]0.5 *38.60490=58.29212kA 短路点4 冲击系数Kc=1.8 电阻Rs =R1 +R2 +R3 +R4 =0.079+0.342+0.560+0.140 =1.12100mΩ 电抗Xs =X1 +X2 +X3 +X4 =0.792+0.327+4.767+1.470 =7.35600mΩ 相保电阻Rφp =Rφp1+Rφp2+Rφp3+Rφp4 =0.053+0.228+0.560+0.540 =1.38100mΩ 相保电抗Xφp =Xφp1 +Xφp2+Xφp3+Xφp4 =0.528+0.218+4.767+3.400 =8.91300mΩ 短路电流总阻抗Zk=(Rs2 +Xs2 )0.5 =(1.121002 +7.356002 )0.5=7.44093mΩ 相保阻抗Zφp=(Rφp2+Xφp2 )0.5 =(1.381002 +8.913002 )0.5=9.01935mΩ 三相短路电流I"=230/Zk=230/7.44093=30.95888kA 单相接地故障电流Id=220/Zkφp =220/9.01935=24.32470kA 短路冲击电流ich=1.414KcId=1.414*1.8*30.95888=78.80844kA 短路全电流最大有效值Ich=[1+2(Kch-1)2 ]0.5 Id=[1+2(1.8-1)2 ]0.5 *30.95888=46.74688kA 短路点5 冲击系数Kc=1.8 电阻Rs =R1 +R2 +R3 +R4 +R5 =0.079+0.342+0.560+0.140+0.015 =1.13600mΩ 电抗Xs =X1 +X2 +X3 +X4 +X5 =0.792+0.327+4.767+1.470+0.008 =7.36400mΩ 相保电阻Rφp =Rφp1+Rφp2+Rφp3+Rφp4+Rφp5 =0.053+0.228+0.560+0.540+0.060 =1.44100mΩ 相保电抗Xφp =Xφp1+Xφp2+Xφp3+Xφp4+Xφp5 =0.528+0.218+4.767+3.400+0.015 =8.92800mΩ 短路电流总阻抗Zk=(Rs2 +Xs2 )0.5 =(1.136002 +7.364002 )0.5=7.45111mΩ 相保阻抗Zφp=(Rφp2+Xφp2 )0.5 =(1.441002 +8.928002 )0.5=9.04354mΩ 三相短路电流I"=230/Zk=230/7.45111=30.91658kA 单相接地故障电流Id=220/Zkφp =220/9.04354=24.25964kA 短路冲击电流ich=1.414KcId=1.414*1.8*30.91658=78.70076kA 短路全电流最大有效值Ich=[1+2(Kch-1)2 ]0.5 Id=[1+2(1.8-1)2 ]0.5 *30.91658=46.68301kA 计算结果 短路点1 短路电流总阻抗Zk=0.79593mΩ 相保阻抗Zφp=0.53065mΩ 三相短路电流I"=289.42580kA 单相接地故障电流Id=413.43957kA 短路冲击电流ich=736.75780kA 短路全电流最大有效值Ich=437.02337kA 短路点2 短路电流总阻抗Zk=1.19558mΩ 相保阻抗Zφp=0.79717mΩ 三相短路电流I"=192.67931kA 单相接地故障电流Id=275.21560kA 短路冲击电流ich=490.48145kA 短路全电流最大有效值Ich=290.93938kA 短路点3 短路电流总阻抗Zk=5.96719mΩ 相保阻抗Zφp=5.57678mΩ 三相短路电流I"=38.60490kA 单相接地故障电流Id=39.34048kA 短路冲击电流ich=98.27203kA 短路全电流最大有效值Ich=58.29212kA 短路点4 短路电流总阻抗Zk=7.44093mΩ 相保阻抗Zφp =9.01935mΩ 三相短路电流I"=30.95888kA 单相接地故障电流Id=24.32470kA 短路冲击电流ich=78.80844kA 短路全电流最大有效值Ich=46.74688kA 短路点5 短路电流总阻抗Zk=7.45111mΩ 相保阻抗Zφp=9.04354mΩ 三相短路电流I"=30.91658kA 单相接地故障电流Id=24.25964kA 短路冲击电流ich=78.70076kA 短路全电流最大有效值Ich=46.68301kA