function [G,B,transY,transG,transB,transG1,transB1,transNum,lineNum,lineI,lineJ,lineB,transI,transJ,transK0,transKmin,transKmax]=...    
    formY(nodeNum,mtrLine,mtrGround,mtrTrans,capI,capK)              
%程序功能：形成节点导纳矩阵
%编写时间：2010年11月

%变量定义：
%G--电导矩阵,B--电纳矩阵，lineI,lineJ--节点序号，lineR--线路电阻
%lineX--线路电抗，groundI--接地支路节点序号
%groundR--接地支路电阻，groundX--接地支路电抗
%transI，transJ--变压器支路节点序号 
%transR--变压器支路电阻，transX--变压器支路电抗
%transK--变压器变比
%transG--变压器支路等效电导，transB--变压器支路等效电纳

%% 利用线路和接地支路参数形成导纳矩阵 
lineI=mtrLine(:,2);                                                         
lineJ=mtrLine(:,3);                                                         
lineR=mtrLine(:,4);                                                        
lineX=mtrLine(:,5);                                                         
lineB=mtrLine(:,6);                                                              
groundI=mtrGround(:,1);                                                                                                        
groundX=mtrGround(:,2);  
Yij=1./(lineR+j*lineX);
Y1=-sparse(lineI,lineJ,Yij,nodeNum,nodeNum)-sparse(lineJ,lineI,Yij,nodeNum,nodeNum)...
    +sparse(lineI,lineI,Yij+j*lineB,nodeNum,nodeNum)+sparse(lineJ,lineJ,Yij+j*lineB,nodeNum,nodeNum)...
    +sparse(groundI,groundI,j*groundX,nodeNum,nodeNum)+sparse(capI,capI,j*capK,nodeNum,nodeNum); 
%% 加入变压器支路修改导纳矩阵
transIall=mtrTrans(:,2);
transJall=mtrTrans(:,3);
transR=mtrTrans(:,4);
transX=mtrTrans(:,5);
transK0all=mtrTrans(:,6);
lineNum=length(lineI)+length(transIall);
transY=1./(transR+j*transX);
Y1=Y1-sparse(transIall,transJall,transY./transK0all,nodeNum,nodeNum)-sparse(transJall,transIall,transY./transK0all,nodeNum,nodeNum)...
    +sparse(transIall,transIall,transY./transK0all./transK0all,nodeNum,nodeNum)+sparse(transJall,transJall,transY,nodeNum,nodeNum);
Yt=sparse(transIall,transJall,-transY,nodeNum,nodeNum);                     %这样处理是因为有两台变压器两端的节点号相同，避免在更新节点导纳矩阵时只识别一台变压器
transIJ=sub2ind(size(Yt),transIall,transJall);
transYt=Yt(transIJ);
transCtrl=mtrTrans(:,9);
ctrTransNum=find(transCtrl);
transI=transIall(ctrTransNum);
transJ=transJall(ctrTransNum);
transKmax=1/0.9*ones(size(transI));
transKmin=1/1.1*ones(size(transI));
transK0=transK0all(ctrTransNum);
transG=real(transYt(ctrTransNum));                                          
transB=imag(transYt(ctrTransNum));
transG1=-real(transY(ctrTransNum));                                         %之所以要取负号是因为transG、transB是作为导纳矩阵中的互导纳来用，在计算自导纳的时候注意要用-transG、-transB!!!!
transB1=-imag(transY(ctrTransNum));
transNum=length(transI);
lineI=[lineI;transI];                                                       %将线路和变压器支路的编号合并，在后面线路约束的时候同时处理
lineJ=[lineJ;transJ];
lineNum=lineNum-length(transIall)+transNum;
%% 求节点导纳的幅值和相角
[Yrows,Ycols,Y1] = find(Y1);
G=real(Y1);
B=imag(Y1);
G=sparse(Yrows,Ycols,G,nodeNum,nodeNum);
B=sparse(Yrows,Ycols,B,nodeNum,nodeNum);