2相短路電流計算與查表

2相短路電流計算與查表解析法計算低壓電網短路電流計算兩相短路電流的計算公式為：I)2(d＝22)()(2XRUeR＝R1/Kb2+Rb+R2X=Xx+X1/Kb2+Xb+X2式中：I)2(d—兩相短路電流，A；R、X—短路回路內一相電阻、電抗值的總和，Ω；Xx—根據三相短路容量計算的係統電抗值，Ω；R1、X1—高壓電纜的電阻、電抗值，Ω；Kb—礦用變壓器的變壓比，若一次電壓為6000V，二次電壓為400、690、1200V時，變比依次為15、8.7、5；當一次電壓為10000V，二次電壓為400、690、1200V時，變比依次為25、14.5、8.3；Rb、Xb—礦用變壓器的電阻、電抗值，Ω；R2、X2—低壓電纜的電阻、電抗值，Ω；Ue—變壓器二次側的額定電壓，V。若計算三相短路電流值I)3(d＝1.15I)2(d礦用橡套電纜的單位長度電阻與電抗阻抗Z0(Ω/km)截麵（mm2）4610162535507095120電阻R05.53.6932.1591.3690.86380.61600.44840.31510.23010.18電抗X00.1010.0950.0920.0900.0880.0840.0810.0780.0750.074380V、660V、1140V係統各電纜的換算係數為下表電纜截麵4610162535507095換算係數11.978.114.753.011.911.371.000.730.53127V係統各電纜的換算係數為下表電纜截麵2.54610換算係數1.641.000.580.34KBSG型變壓器二次側電壓690V兩相短路電流計算表（2）電纜換算長度(m)變壓器容量(kVA)50100200315400500630800100009051812362556997244906591291057612085208951774348453686712822583259494106874088417363333499961177296740282649107608741696317746265534643065287146772580863165630214271500156815766621166151008531616287039434531505251245451574112084215752725364641234528458948