%本程序的功能是用牛頓-拉夫遜法進行潮流計算
n=input('請輸入節點數:n=');
nl=input('請輸入支路數:nl=');
isb=input('請輸入平衡母線節電號:isb=');
pr=input('請輸入誤差精度:pr=');
B1=input('請輸入由支路參數形成的矩陣:B1=');%變壓器側為1，否則為0
B2=input('請輸入各節點參數形成的矩陣:B2=');
X=input('請輸入由節點號及其對地阻抗形成的矩陣:X=');
Y=zeros(n);U=zeros(1,n);cta=zeros(1,n);V=zeros(1,n);O=zeros(1,n);S1=zeros(nl);
for i=1:n
    if X(i,2)~=0;
        p=X(i,1);
        Y(p,p)=X(i,2);
    end
end
for i=1:nl
    if B1(i,6)==0
        p=B1(i,1);q=B1(i,2);
    else p=B1(i,2);q=B1(i,1);
    end
    Y(p,q)=Y(p,q)-1./(B1(i,3)*B1(i,5));
    Y(q,p)=Y(p,q);
    Y(q,q)=Y(q,q)+1./(B1(i,3)*B1(i,5)^2)+B1(i,4)./2;
    Y(p,p)=Y(p,p)+1./B1(i,3)+B1(i,4)./2;
end %求導納矩陣
G=real(Y);B=imag(Y);
for i=1:n
    cta(i)=angle(B2(i,3));
    U(i)=abs(B2(i,3));
    %V(i)=B2(i,4);
end
for i=1:n
    S(i)=B2(i,1)-B2(i,2);
    B(i,i)=B(i,i)+B2(i,5);
end
P=real(S);Q=imag(S);
ICT1=0;IT2=1;
while IT2~=0
    IT2=0;t1=1;t2=1;
    for i=1:n
        if i~=isb
            C(i)=0;
            D(i)=0;
            for j1=1:n
                C(i)=C(i)+U(i)*U(j1)*(G(i,j1)*cos(cta(i)-cta(j1))+B(i,j1)*sin(cta(i)-cta(j1)));
                D(i)=D(i)+U(i)*U(j1)*(G(i,j1)*sin(cta(i)-cta(j1))-B(i,j1)*cos(cta(i)-cta(j1)));
            end
            DP(t1)=P(i)-C(i);
            t1=t1+1;
            if B2(i,6)==2
                DQ(t2)=Q(i)-D(i);
                t2=t2+1;
            end 
        end
    end
    t1=t1-1;t2=t2-1;
    DPQ=[DP';DQ']; %求DP,DQ
    for i=1:t1+t2
        if abs(DPQ(i))>pr
            IT2=IT2+1;
        end
    end
    H=zeros(t1,t1);N=zeros(t1,t2);K=zeros(t2,t1);L=zeros(t2,t2);
    for i=1:t1
        for j1=1:t1
            if j1~=isb&j1~=i
               H(i,j1)=0-U(i)*U(j1)*(G(i,j1)*sin(cta(i)-cta(j1))-B(i,j1)*cos(cta(i)-cta(j1)));
           elseif j1~=isb&j1==i
               H(i,j1)=U(i)^2*B(i,j1)+D(i);
           end
        end
    end
    for i=1:t1
        for j1=1:t2
            if j1~=isb&j1~=i
                N(i,j1)=0-U(i)*U(j1)*(G(i,j1)*cos(cta(i)-cta(j1))+B(i,j1)*sin(cta(i)-cta(j1)));
            elseif j1~=isb&j1==i
                N(i,j1)=0-U(i)^2*G(i,j1)-C(i);
            end
        end
    end
    for  i=1:t2
        for j1=1:t1
            if j1~=isb&j1~=i
                K(i,j1)= U(i)*U(j1)*(G(i,j1)*cos(cta(i)-cta(j1))+B(i,j1)*sin(cta(i)-cta(j1)));
            elseif j1~=isb&j1==i
                K(i,j1)=U(i)^2*G(i,j1)-C(i);
            end
        end
    end
    for i=1:t2
        for j1=1:t2
            if j1~=isb&j1~=i
                L(i,j1)=0-U(i)*U(j1)*(G(i,j1)*sin(cta(i)-cta(j1))-B(i,j1)*cos(cta(i)-cta(j1)));
            elseif j1~=isb&j1==i
                L(i,j1)=U(i)^2*B(i,j1)-D(i);
            end
        end
    end
    J=[H,N;K,L];%求雅可比矩陣
    modify=-J\DPQ;
    Dcta=modify([1:t1],:);
    t3=U(:,[1:t2]);
    DU=diag(t3,0)*modify([t1+1:t1+t2],:);
    t4=1;
    for i=1:t1
        if B2(i,6)~=1
        cta(1,i)=cta(1,i)+Dcta(t4,1);
        t4=t4+1;
        end
    end
    t5=1;
    for i=1:t2
        if B2(i,6)==2
        U(1,i)=U(1,i)+DU(t5,1);
        t5=t5+1;
        end
    end
    ICT1=ICT1+1;
end   %修正原值
for i=1:n
    UU(i)=U(i)*cos(cta(i))+1i*U(i)*sin(cta(i));
end
for p=1:n
    c(p)=0;
    for q=1:n
    c(p)=c(p)+conj(Y(p,q))*conj(UU(q));
    end
    s(p)=UU(p)*c(p);
end
disp('--------------------------------------------------------------------------------');
disp('各節點電壓U為（節點從小到大排列）:');
disp(UU);
disp('--------------------------------------------------------------------------------');
disp('各節點電壓相角為（節點從小到大排列）:');
disp(180*angle(UU)/pi);
disp('--------------------------------------------------------------------------------');
disp('按公式計算全部線路功率，結果如下:');
for i=1:nl
    if B1(i,6)==0
        p=B1(i,1);q=B1(i,2);
    else p=B1(i,2);q=B1(i,1);
    end
    Si(p,q)=UU(p)*(conj(UU(p))*conj(B1(i,4)./2)+(conj(UU(p)*B1(i,5))-conj(UU(q)))*conj(1./(B1(i,3)*B1(i,5))));%各條支路首端功率Si
    f=[p,q,Si(p,q)];
    disp(f);
end
for i=1:nl
    if B1(i,6)==0
        p=B1(i,1);q=B1(i,2);
    else p=B1(i,2);q=B1(i,1);
    end
    Sj(q,p)=UU(q)*(conj(UU(q))*conj(B1(i,4)./2)+(conj(UU(q)./B1(i,5))-conj(UU(p)))*conj(1./(B1(i,3)*B1(i,5))));%各條支路末端功率Sj
    f=[q,p,Sj(q,p)];
    disp(f);
end
disp('--------------------------------------------------------------------------------');
disp('各條支路的功率損耗DS為(順序同您輸入B1時一樣):');
for i=1:nl
    if B1(i,6)==0
        p=B1(i,1);q=B1(i,2);
    else p=B1(i,2);q=B1(i,1);
        end
    DS(i)=Si(p,q)+Sj(q,p);%各條支路功率損耗DS
    disp(DS(i));
end
Sp=0;
for i=1:n
    Sp=Sp+UU(isb)*conj(Y(isb,i))*conj(UU(i));
end
disp('平衡節點的功率:');
disp(Sp);