(完整版)前推回代法计算流程

前推回代法计算流程
要看懂前推回代法计算程序， 报告叙述计算原理及计算流程。

绘制计算流程框图。

确定前推回代 支路次序（广度优先，或深度优先） ，编写前推回代计算输入文件。

进行潮流计算。

下列为节点配电网结构图及系统支路参数和系统负荷参数表。

1
62
11 12
13
2
10
主程序清单：
[PQ,FT,RX]=case114(); %调用数据文件
NN=size(PQ,1); %节点数
NB=size(FT,1); %支路数数
%V 初始电压相量
V=PQ(:,1);
maxd=1
k=1
while maxd>0.0001
PQ2=PQ; %每一次迭代各节点的注入有功和无功相同
PL=0.0;
for i=1:NB
kf=FT(i,1); %前推始节点号
kt=FT(i,2); %前推终节点号
x=(PQ2(kf,2)^2+PQ2(kf,3)^2)/V(kf)/V(kf); %计算沿线电流平方A
PQ1(i,1)=PQ2(kf,2)+RX(i,1)*x; %计算支路首端有功/MW RX(i,1)~R
PQ1(i,2)=PQ2(kf,3)+RX(i,2)*x; %计算沿支路的无功损耗/Mvar RX(i,2)~X
PQ2(kt,2)= PQ2(kt,2)+PQ1(i,1); %用PQ1去修正支路末端节点的有功P 单位MW PQ2(kt,3)= PQ2(kt,3)+PQ1(i,2); %用PQ1去修正支路末端节点的有功Q 单位Mvar
end angle(1)=0.0;
for i=NB:-1:1
kf=FT(i,2); %回代始节点号
kt=FT(i,1); %回代终节点号
dv1=(PQ1(i,1)*RX(i,1)+PQ1(i,2)*RX(i,2))/V(kf);
dv2=(PQ1(i,1)*RX(i,2)-PQ1(i,2)*RX(i,1))/V(kf);
V2(kt)=sqrt((V(kf)-dv1)^2+dv2^2);
angle(kt)=angle(kf)+atand(dv2/(V(kf)-dv1));
end maxd=abs(V2(2)-V(2));
V2(1)=V(1);
for i=3:1:NN
if abs(V2(i)-V(i))>maxd;
maxd=abs(V2(i)-V(i));
end
end
maxd
k=k+1
PQ1 %潮流分布即支路首端潮流M V=V2 % 节点电压模计算结果kV
angle %节点电压角度计算结果单位度
PL %网损单位MW
end
clear
输入文件清单：
function [PQ,FT,RX]=case114()
PQ=[
%节点电压有功无功
PL=PL+RX(i,1)*x;
%计算支路电压损耗的纵分量%计算支路电压损耗的横分量%计算支路末端电压/kV %计算支路dv1 dv2
10.4 0 0
10.0 0.0342 0.0301 10.0 0.0693 0.0642 10.0 0.0845 0.0763 10.0 0.0295 0.0261 10.0 0.0474 0.0409 10.0 0.1176 0.0957 10.0 0.0946 0.0857 10.0 0.0916 0.0859 10.0 0.0271 0.0229 10.0 0.0696 0.0643 10.0 0.0676 0.0579 10.0 0.0298 0.0242 ];
FT=[
%首端末端
5 4
13 4
4 3
10 3
12 11
11 3
7 6
6 2
9 8
8 2
3 2
2 1
];
RX=[
% R X
4.524
5.04
3.521 3.966
1.145 1.28
4.14 4.696
2.436 2.866
1.328 1.763
2.745 2.965
0.856 1.14
2.237 2.756
3.743
4.251
2.356 2.541
3.367 3.685
]; 计算过程maxd = 1
maxd =
0.1780
k =
2
PQ1 =
0.0296 0.0262
0.0299 0.0243
0.1443 0.1272
0.0272 0.0230
0.0678 0.0581
0.1378 0.1230
0.1182 0.0964
0.1660 0.1378
0.0920 0.0863
0.1890 0.1748
0.3847 0.3439
0.8099 0.7260
V =
Columns 1 through 8
10.4000 9.8807 9.8220 9.9672 9.9734 9.9701
9.9390 9.8550
Columns 9 through 13
9.9556 9.9780 9.9600 9.9668 9.9799 angle =
Columns 1 through 8
0 0.3011 0.3986 0.4211 0.4387 0.3421 0.3916
0.3878
Columns 9 through 13
0.0471
maxd =
0.1787
PQ1 =
0.0296 0.0262
0.0299 0.0243
0.1443 0.1272
0.0272 0.0230
0.0678 0.0581
0.1378 0.1230
0.1182 0.0964
0.1660 0.1378
0.0920 0.0863
0.1890 0.1749
0.3849 0.3442
0.8112 0.7274
V =
Columns 1 through 8
10.4000 9.8798 9.7004 9.7886 9.9405 9.8504 9.9089 9.7338
Columns 9 through 13
9.8100 9.7996 9.7813 9.9267 9.9470 angle =
Columns 1 through 8
0 0.3011 0.4011 0.4244 0.4421 0.3431
0.3929 0.3899
Columns 9 through 13
0.0484 maxd =
0.1793
PQ1 =
0.0296 0.0262
0.0299 0.0243
0.1444 0.1272
0.0272 0.0230
0.0678 0.0581
0.1379 0.1231
0.1182 0.0964
0.1661 0.1378
0.0920 0.0864
0.1891 0.1749
0.3851 0.3444
0.8115 0.7277
Columns 1 through 8
10.4000 9.8796 9.6994 9.6666 9.7614 9.8495 9.7884 9.7329
Columns 9 through 13
9.6883 9.6777 9.6591 9.7474 9.7680 angle = Columns 1 through 8
0 0.3011 0.4011 0.4250 0.4433 0.3431 0.3942 0.3899
Columns 9 through 13
0.4266 0.4209 0.4498 0.4814 0.4447
PL =
0.0487
maxd =
0.1226
k =
5
PQ1 =
0.0296 0.0262
0.0299 0.0243
0.1444 0.1272
0.0272 0.0230
0.0678 0.0581
0.1379 0.1231
0.1183 0.0964
0.1661 0.1379
0.0920 0.0864
0.1891 0.1750
0.3852 0.3444
0.8115 0.7278
V =
Columns 1 through 8
10.4000 9.8795 9.6991 9.6656 9.6391 9.8493 9.7875 9.7326
Columns 9 through 13
9.6873 9.6767 9.6581 9.6248 9.6457
angle =
Columns 1 through 8
0 0.3011 0.4011 0.4250 0.4438 0.3431 0.3942 0.3899
Columns 9 through 13
0.4266 0.4209 0.4498 0.4822 0.4452
PL =
0.0487
maxd =
0.0010
k =
PQ1 =
0.0296 0.0262
0.0299 0.0243
0.1444 0.1273
0.0272 0.0230
0.0678 0.0581
0.1379 0.1231
0.1183 0.0964
0.1661 0.1379
0.0920 0.0864
0.1891 0.1750
0.3852 0.3445
0.8116 0.7278
V =
Columns 1 through 8
10.4000 9.8795 9.6991 9.6653 9.6381 9.8492 9.7873 9.7326
Columns 9 through 13
9.6870 9.6764 9.6579 9.6238 9.6447 angle = Columns 1 through 8
0 0.3011 0.4011 0.4250 0.4438 0.3431 0.3942 0.3899
Columns 9 through 13
0.4266 0.4209 0.4498 0.4823 0.4452
PL =
0.0488
maxd =
2.6021e-004
PQ1 =
0.0296 0.0262
0.0299 0.0243
0.1444 0.1273
0.0272 0.0230
0.0678 0.0581
0.1379 0.1231
0.1183 0.0964
0.1661 0.1379
0.0920 0.0864
0.1891 0.1750
0.3852 0.3445
0.8116 0.7278
V =
Columns 1 through 8
10.4000 9.8795 9.6991 9.6652 9.6378 9.8492 9.7872 9.7326
Columns 9 through 13
9.6870 9.6764 9.6578 9.6235 9.6445 angle =
Columns 1 through 8
0 0.3011 0.4011 0.4250 0.4438 0.3431 0.3942 0.3899 Columns 9 through 13
11
0.4266 0.4209 0.4498 0.4823 0.4452
PL =
0.0488 maxd =
6.1046e-005
PQ1 =
0.0296 0.0262
0.0299 0.0243
0.1444 0.1273
0.0272 0.0230
0.0678 0.0581
0.1379 0.1231
0.1183 0.0964
0.1661 0.1379
0.0920 0.0864
0.1891 0.1750
0.3852 0.3445
0.8116 0.7278
V =
Columns 1 through 8
10.4000 9.8795 9.6991 9.6652 9.6377 9.8492 9.7326
Columns 9 through 13
angle =9.7872
9.6870 9.6764 9.6578 9.6235 9.6444
12
Columns 1 through 8
0 0.3011 0.4011 0.4250 0.4438 0.3431 0.3942
0.3899
Columns 9 through 13
0.4266 0.4209 0.4498 0.4823 0.4452
PL =
0.0488
计算结果清单：
maxd = 1
k = 1
maxd = 0.1780
k = 2
maxd = 0.1787
k = 3
maxd = 0.1793
k = 4
maxd = 0.1226
k = 5
maxd = 0.0010
k = 6
maxd = 2.6021e-04
k = 7
maxd = 6.1046e-05
k = 8
PQ1 =
0.0296 0.0262
0.0299 0.0243
0.1444 0.1273
0.0272 0.0230
0.0678 0.0581
0.1379 0.1231
0.1183 0.0964
0.1661 0.1379
0.0920 0.0864
0.1891 0.1750
0.3852 0.3445
0.8116 0.7278
V =
13
10.4000 9.8795 9.6991 9.6652 9.6377 9.8492 9.7872 9.7326 9.6870 9.6764 9.6578 9.6235 9.6444
angle =
0 0.3011 0.4011 0.4250 0.4438 0.3431 0.3942 0.3899 0.4266 0.4209
0.4498 0.4823 0.4452
PL = 0.0488
参考文献
[1] 何仰赞温增银《电力系统分析》．华中科技大学出版社.
[2] 李维波. 《MATLAB在电气工程中应用》．中国电力出版社.2007
14。