说明：  标准极坐标牛顿潮流，包含导纳矩阵生成过程，以中国电力出版社出版《电力系统分析计算机算法》例题2.1为算例
(Standard polar coordinates NEWTON, including admittance matrix generation process, with China Electric Power Publishing House " power system analysis computer algorithms," Example 2.1 as an example)