中文说明：%利用线路数据建立母线导纳矩阵
English Description：
%Formation of bus admittance matrix using line data j=sqrt(-1);i=sqrt(-1); tic; baseimp=(basekv*basekv)/basemva; Ibase=basemva*1000/(sqrt(3)*(basekv)); % Input for line-data n1 = linedata(:,1); % source bus nr = linedata(:,2);