序号电路元件计算公式1电网300100.3332进线电缆YJV-3X30020.0790.1430.47719.218209.8048.9130.634.50%0.01140.34526.569290.0667.620.6144YJV-3X700.80.0710.0520.52817.343189.3444.145YJV-3X1852.50.0630.1430.62014.786161.4237.6360.254.50%0.02880.64814.129154.2535.960.3267YJV-3X700.80.0710.0520.67113.651149.0334.748YJV-3X1851.50.0630.086Xjs3*=X1*+X2*+X8*0.56216.289177.8241.4690.54.50%0.0144xjs4*=X1*+X2*+X8*+X9*0.57715.882173.3840.420.36710YJV-3X700.80.0710.0520.61414.922162.9037.9817%0.03710KV电网短路电流计算假定电网短路容量为300MVA,基准电压Uj=10KV,基准电流Ij=9.16KA,冲击系数Kch.s取1.8.各元件有效电阻较小,短路电路中总电阻不大于总电抗的1/3,不予考虑.10KV|---2.0Km3X300电缆------10KV变配电所SS2|F1--------2.5Km3X185电缆--------F4|SS110/0.4KV变压器|F5b|---SS210/0.4KV变压器|F2|----0.8Km3X70电缆----10KV电机|F6b|----1.5Km3X70电缆----10KV电机|F3b|----------1.5Km3X185电缆--------F7|SS310/0.4KV变压器|F8b|----1.0Km3X70电缆----10KV电机|F9变压器/电网容量SrT/SksMVA电缆长度Km变压器Uk%短路电路总电抗Xjs超瞬变短路电流KA短路容量MVA短路全电流KA折算到高压侧的短路电流(KA)阻抗/Km短路元件电抗(标值)I"s=I0.2=Ik=Ij/Xjs*Ss"=Sj/Xjs*ich.s=1.414*Kch.s*I"I1=I2/(1.732*nl)X1*=Sj/SksX2*=L*X(Sj/Uj^2)短路点F1SS210KV母线Xjs1*=X1*+X2*SS2变压器(基准电压10KV)X3*=(Uk%/100)*(Sj/SrT)*(0.4^2/10^2)短路点F2SS2变压器低压侧Xjs2*=X1*+X2*+X3*SS2-10KV电机X4*=L*X(Sj/Uj^2)短路点F3Xjs3*=X1*+X2*+X4*SS2-SS1电缆X5*=L*X(Sj/Uj^2)短路点F4SS110KV母线Xjs4*=X1*+X2*+X5*SS1变压器(基准电压10KV)X6*=(Uk%/100)*(Sj/SrT)*(0.4^2/10^2)短路点F5SS1变压器低压侧Xjs5*=X1*+X2*+X5*+X6*SS1-10KV电机X7*=L*X(Sj/Uj^2)短路点F6Xjs3*=X1*+X2*+X5*+X7*SS2-SS3电缆X8*=L*X(Sj/Uj^2)短路点F7SS310KV母线SS3变压器(基准电压10KV)X9*=(Uk%/100)*(Sj/SrT)*(0.4^2/10^2)短路点F8SS3变压器低压侧SS3-10KV电机X10*=L*X(Sj/Uj^2)短路点F9Xjs3*=X1*+X2*+X8*+X10*400kw10KV电机X"d*=Xd"(Sj/Sed)KkKkKjxKhn11.051.110.851036.44.55.050.00I2"k3.maxI1"k3.minI2"k3.minI22k1.minKkKkKjxKhKghn1Km=I2"k2.min/Idz81014656405157901.31.510.8521028.98.89.090.003.9瞬动电流倍数I2"k3.maxI1"k3.minI2"k3.minI22k1.minKkKkKjx...
