Yn0_1 = [2,1;1,2];
%分割后 节点导纳矩阵
Yn0 = [Yn0_1     ,zeros(2,2),zeros(2,2);
       zeros(2,2),Yn0_1     ,zeros(2,2);
       zeros(2,2),zeros(2,2),Yn0_1];
% 变动支路导纳矩阵
Yb_delt = [1,0,0;
           0,1,0;
           0,0,1];
 % 节点-变动支路矩阵     
 A = [1, 0,0;
      0, 1,0;
      0,-1,0;
      0, 0,1;
      0, 0,-1;
      -1,0,0];
  
  %注入节点电流列向量
  In = [-1,1,2,-2,3,-3]';
  
  % 分割支路电流
  X = inv(inv(Yb_delt) + A'*inv(Yn0)*A)*(A'*inv(Yn0)*In);
  % 节点电压
  Un = inv(Yn0) * (In - A*X);