由π型模块级联成的简单电网作潮流计算的一种情况：已知始端电压和末端复功率及电网各处参数，利用前推回代法求始端复功率和末端电压(A simple power grid cascaded by PI module is used for power flow calculation: the initial terminal voltage and terminal complex power and the parameters of the grid are known. The forward