用节点导纳矩阵计算三相短路电流。输入数据-形成节点阻抗矩阵-选择故障点-计算短路电流-计算个节点电压-计算指定支路的电流-this procedure is used node admittance matrix calculation of three-phase short-circuit current input data-- forming node impedance matrix-- election Optional fault-calculation of short-circuit current-voltage computing nodes designated calculated slip road-- Electricity