说明：  自编牛拉法算电力系统潮流的matlab小程序，可以运行，有简单的中文注释。5节点系统，包括求节点导纳矩阵，求雅可比矩阵等系列过程。
(The matlab program for calculating the power flow of power system based on the niula method is compiled by ourselves, which can be run and has simple Chinese notes. 5-node system, including the node admittance matrix, Jacobian matrix and other processes.)