前推回代潮流计算程序

function Flow1(Z,S,Sb,Vb)

% Z 各支路阻抗

% S 各节点运算负荷

% Sb 基准功率

% Zb 基准阻抗

% Flow(Z,S,Sb,Vb) 计算网络功率及电压分布

% 输出收敛迭代次数及功率分布和电压分布

% 数据初始化

Z(:,1)=Z(:,1)+1;

Z1=[1,0,1,0];

Z=[Z1;Z];%使得支路编号与支路末点编号一致

[m,n]=size(Z);

Zb=(Vb^2)/Sb*1000;

Z(:,4)=Z(:,4)/Zb;

S(:,2)=S(:,2)/Sb;

k=1;

V=ones(m,1);

dU=ones(m,1);

%前推回代

n=0;

while max(abs(dU))>10^-4

Sr=S(:,2);

V1=V;

for i=m:-1:1 %前推功率

A=(find(Z(:,2)==i));%求以i节点为始点的各支路

[b,c]=size(A);

if b~=0

for j=1:1:b %求以当前节点为始点的各支路功率总和

N=A(j,1);

if N~=6

dSr=((abs(Sr(N,1))/V(N,1))^2)*Z(N,4); %各支路功率损耗else

dSr=0;

end

Sr(N,2)=Sr(N,1)+dSr; %N支路功率

Sr(i,1)=Sr(i,1)+Sr(N,2);

end

else

Sr(i,2)=Sr(i,1);

end

end

V(1,1)=1;

for t=2:m %回代电压

if t~=6

a=Z(t,2); %由于是辐射型网络，只有一个始点

dV1=(real(Sr(t,2))*real(Z(t,4))+imag(Sr(t,2))*imag(Z(t,4)))/V(a,1);

dV2=(real(Sr(t,2))*imag(Z(t,4))-imag(Sr(t,2))*real(Z(t,4)))/V(a,1);

V(t,1)=((V(a,1)-dV1)^2+dV2^2)^0.5 ;

else

dk=k*(V(5,1)/V1(5,1)-1)

k=k-dk

if k>=1.1

k=1.1;

elseif k<=0.9

k=0.9;

else

%k=vpa(k,3);

k=round(k*100)/100

end

k

V(6,1)=k*V(5,1);

end

end

dU=V-V1;

n=n+1;

if n>15

fprintf('迭代15次不收！\n');

break;

end

end

%输出

a=1:1:m;%编号

fprintf('迭代收敛次数为：\n');

n

fprintf('网络功率分布为：\n');

Sr(:,2)=Sr(:,2)*Sb;

Sr=[a',Sr]

fprintf('网络电压分布为：\n');

%V=V*Vb;

V=[a',V]

clc

clear all;

Z2=[

1, 1, 2, 1.197+j*0.82 ;

2, 2, 3, 1.796+j*1.231;

3, 3, 4, 1.306+j*0.895;

4, 4, 5, 1.851+j*1.268;

5, 5, 6, 1.524+j*1.044;

6, 6, 7, 1.905+j*1.305;

7, 7, 8, 1.197+j*0.82 ;

8, 8, 9, 0.653+j*0.447;

9, 9, 10, 1.143+j*0.783;

10, 4, 11, 2.823+j*1.172;

11, 11, 12, 1.184+j*0.491;

12, 12, 13, 1.002+j*0.416;

13, 13, 14, 0.455+j*0.189;

14, 14, 15, 0.546+j*0.227;

15, 5, 16, 2.55+j*1.058;

16, 6, 17, 1.366+j*0.567;

17, 17, 18, 0.819+j*0.34 ;

18, 18, 19, 1.548+j*0.642;

19, 19, 20, 1.368+j*0.567;

20, 20, 21, 3.552+j*1.474;

21, 7, 22, 1.548+j*0.642;

22, 22, 23, 1.092+j*0.453;

23, 23, 24, 0.91+j*0.378;

24, 24, 25, 0.455+j*0.189;

25, 25, 26, 0.364+j*0.151;

26, 8, 27, 1.002+j*0.417;

27, 27, 28, 4.403+j*1.215; ];

S2=[

1, 0;

2, 35.28;

3, 14;

4, 35.28;

5, 14;

6, 35.28;

7, 35.28;

8, 35.28;

9, 14;

10, 14;

11, 56;

12, 35.28;

13, 35.28;

14, 14;

15, 35.28;

16, 35.28;

17, 8.96;

18, 8.96;

19, 35.28;

20, 35.28;

21, 14;

22, 35.28;

23, 8.96;

24, 56

25, 8.96;

26, 35.28;

27, 35.28;

28, 35.28;

];%28nodes data

J=[

5.441, 2.946 , 2.946 ;

2.946, 8.848 , 5.258 ;

2.946, 5.258 , 8.376 ;

];

c=0.7;

Vb=10.5;

Sb=100;

Z2(:,4)=Z2(:,4);

S2(:,2)=S2(:,2);

S2(:,2)=S2(:,2)+i*(S2(:,2)*tan(acos(c))); Z=Z2;

S=S2;

%Flow(Z,S,Sb,Vb,J);

Flow1(Z,S,Sb,Vb);