编号，把原题中的节点1,2,3,4,5重新依次编号为5,1,2,3,4，其中1-4号为PQ节点，5号为平衡节点，计算注入节点的功率、电流-No, the original title of the node re-numbered 5,1,2,3,4 1,2,3,4,5, including 1-4 as PQ node, on the 5th of balance node, compute nodes injection power, current