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各位~~我根据下图的一个系统用MATLAB编写了一段程序,是电流型前推回代法的三相配电系统潮流计算,但是现在结果不是我想要的,不收敛。请各位帮我看一下,提提建议。图片见附件了。还有个问题:已知的线路都是三相对称线路的阻抗值,那么线路的阻抗矩阵中的互阻抗应该如何计算,是什么样的形式,应用怎样的公式?这里我不是很清楚。- %程序名:qiantuihuitui_I_3.m + Q* s' Z8 ~" S$ B5 K
- %功能:支路电流前推回推法求解潮流
1 D) O: }3 q5 G, \& p - clc ) }; ?+ ]5 K& F
- clear all; , Z: R2 N) H8 @* u* F8 q
- %--------------输入网络参数-------------- ( t; m# Y( c" X4 I8 D
- %1-支路编号,2-首节点,3-尾节点,4-自阻抗,5-尾节点复功率,6-支路性质(1-馈线段支路,2-变压器支路),7-尾节点是否带负荷! K$ p' P5 J$ N. T+ P. U
- DB=[1 1 2 0.000167+j*0.000208 0.42+j*0.31 1 1
5 a. D, x* t# ]7 i! J, D4 d6 S% _' a - 2 2 3 0.000151+j*0.000188 6.15 1 05 |! A; x/ ]* k+ V
- 3 2 4 0.000066+j*0.000082 0.38+j*0.29 1 1
) m+ q; Z0 C$ a2 Y7 v- a! b - 4 2 5 0.000249+j*0.000310 0 1 0; K# [- ^2 b& J( C
- 5 2 6 0.000172+j*0.000215 0 1 0
6 U7 @% R c% \$ @4 {3 @ - 6 4 7 0.000156+j*0.000195 6.06 1 03 O9 n' ^( v9 P- @. ]
- 7 4 8 0.000162+j*0.000202 6.04 1 0
) L4 X" w0 U3 f, O- J- T/ Z - 8 4 9 0.000345+j*0.000430 0 1 0
/ \" R3 ~' c/ e- a% L - 9 4 10 0.000287+j*0.000358 0 1 0
2 q* P+ M2 M, U0 ^2 }; P - 10 5 11 0.020563+j*0.321594 0 2 0
# `% y& n8 f7 c- z6 _$ R - 11 6 12 0.020563+j*0.321594 0 2 0
4 i# B& S# e# E3 S - 12 9 13 0.020563+j*0.321594 0 2 0
, X; g% E: \, i' W; x) W5 Q - 13 10 14 0.020563+j*0.321594 0 2 0
6 B) L& V& t. T, {. g6 _ - 14 11 15 0.000237+j*0.000408 5.72+j*0.12 1 1
. L6 ~) E. [" ~: |" s/ u3 {8 _+ p% [ - 15 12 16 0.000237+j*0.000408 5.76+j*0.09 1 1% x1 x$ ]% G4 Q4 M! {: U8 O
- 16 13 17 0.000292+j*0.000502 5.86+j*0.11 1 1
# E5 t/ K) g/ x: i5 D - 17 14 18 0.000274+j*0.000470 5.81+j*0.14 1 1];
5 B0 ?$ G# ? a1 n7 ~' A - [n,m]=size(DB);
+ p. _. I" Y0 E- ]% \5 f - B=[1 sin(2*pi/3)+j*cos(2*pi/3) sin(4*pi/3)+j*cos(4*pi/3)];
0 E; p: q/ u* l% j - C=[1.02 1 1.02 1 1 1 1.02 1.02 1 1 1 1 1 1 1 1 1 1];
, t/ I& q" r) Y7 J x7 k& Q - U(:,1)=B(1,1)*C';$ \7 z" I3 t* c1 e9 P: w5 |$ p
- U(:,2)=B(1,2)*C';% \+ T" }) g) O+ y) n
- U(:,3)=B(1,3)*C';4 V" m+ D4 A2 O' A# T
- %-------------------求解潮流-----------------
+ ^( q3 f, z$ V) p - for k=1:15
/ i4 [% V5 J7 U" M# B9 Z - % I(:,k)=((DB(:,5).')*(diag(1./U(:,k))))';
& ], E' v6 v+ ~+ N. N. q7 _. F0 A j; b - for i=n:-1:1 ' e- A$ \% d# X
- %如果尾节点带恒功率负荷,需计算节点上负荷注入的电流
3 O; e7 R& f& p) i- \8 o& O+ q - if DB(i,7)==1. o* P2 e k) I
- c=DB(i,5)/3;3 I0 {% _* d) x$ l
- d=c/U(i+1,(3*k-2));
; b4 [9 B& V T6 G [ - IL(i,3*k-2)=conj(d);; y# n8 }+ I$ [, ]
- d=c/U(i+1,3*k-1);/ @& o8 v8 X$ R+ Z* ^" w. O
- IL(i,3*k-1)=conj(d);
, J( O% @/ L8 S - d=c/U(i+1,3*k);
# ~; z# g& Q7 u - IL(i,3*k)=conj(d);! K! {7 z/ B: h. s4 T
- else
! W0 ?& p1 g2 H" c - IL(i,3*k-2)=0;$ H" Y8 L1 q& l) ~
- IL(i,3*k-1)=0;5 J9 i+ F' K0 G: G& @3 j( L
- IL(i,3*k)=0;! Z+ e6 x; N3 l0 E: B4 Q
- end
/ Q( D! n0 R: h' ^; C7 T - %找出所有与尾节点相连的支路,计算进支电流(末端电流),存IKj8 D. E# ?6 n9 c6 s& x+ v. U
- A=(find(DB(:,2)==(i+1)));
% B* Z% H* `0 Q/ L" d$ z# q( k* m - if isempty(A)~=1. K" N2 f+ h$ K
- IKj(i,3*k-2)=IL(i,3*k-2)-sum(IKj(A,3*k-2));2 a# k* }- q, `. g" D+ s7 M
- IKj(i,3*k-1)=IL(i,3*k-1)-sum(IKj(A,3*k-1));- g# J5 d- D: r' h' f5 j5 F- c
- IKj(i,3*k)=IL(i,3*k)-sum(IKj(A,3*k));
# e8 N. v+ H1 ?+ p& W - else6 X1 z/ e. ^; T8 y
- IKj(i,3*k-2)=IL(i,3*k-2);- p( l. |- g0 X+ k- X# y
- IKj(i,3*k-1)=IL(i,3*k-1);; [& Y* A p% g) p
- IKj(i,3*k)=IL(i,3*k);: X& i1 U! q8 H% [. u6 G
- end/ Q. M" ^8 ~; E- a9 w* U: ^, _
- %计算出支电流(始端电流),存IKi6 ]8 {9 u3 t7 M4 c/ Z
- a=DB(i,2);
! H1 f X+ }$ h$ {1 g+ Y - b=DB(i,3);0 W8 ]5 H$ D! s2 U. G9 C# p
- Yi=1/DB(i,4)*eye(3);4 @3 f" F* d9 A8 Q( O
- if DB(A,6)==12 J% I7 U* T5 h2 Z( y# I/ E
- F=0.5*Yi*[(U(a,3*k-2)+U(b,3*k-2)) (U(a,3*k-1)+U(b,3*k-1)) (U(a,3*k)+U(b,3*k))]'+[IKj(i,3*k-2) IKj(i,3*k-1) IKj(i,3*k)]';1 `& u$ F& q1 C" r& L3 T
- IKi(i,3*k-2)=F(1,1);
- r- P/ v+ ]! r( G' r, X - IKi(i,3*k-1)=F(2,1);- [1 m: c o0 M, @( q+ h+ B
- IKi(i,3*k)=F(3,1);. m7 v- n J6 x, ^" D \ u
- else
3 u" Z& n: d+ |/ ^1 Q - YT=1/real(DB(i,4))+j*(1/imag(DB(i,4)));+ [7 }+ b3 `/ F1 L* G
- YI=YT*eye(3);
) L2 v. Z7 X" u( K - YII=YT*eye(3);
! {2 u. `# m0 x, e$ |5 J5 s - YIII=-YT*eye(3);, f" u' n1 J- D& m3 [
- D=inv(YIII)*(-[IKj(i,3*k-2) IKj(i,3*k-1) IKj(i,3*k)]'-YII*([U(b,3*k-2) U(b,3*k-1) U(b,3*k)]'));0 r( F! h" x8 m' t, y/ w
- U(a,3*k+1)=D(1,1);6 y4 s5 M, W; S1 G! y) ]7 D& c1 A$ G
- U(a,3*k+2)=D(2,1);% F/ l' ]% u+ s) }* w' F3 e2 C
- U(a,3*k+3)=D(3,1);
4 U( @4 K& Z' X& d2 N# A; m - E=YI*[U(a,3*k+1) U(a,3*k+2) U(a,3*k+3)]'-YIII*[U(b,3*k-2) U(b,3*k-1) U(b,3*k)]';
" z) O2 @3 y8 R( b. ~- z. e - IKi(i,3*k-2)=E(1,1);# a4 _$ X `: W; f3 _ C }
- IKi(i,3*k-1)=E(2,1);4 I, Q8 [, Z) z! L$ Q+ j+ f
- IKi(i,3*k)=E(3,1);
/ k- R, H* }; Z - end
$ a# e2 k' J5 I - end
5 \) g! Z! o) u: ]5 d; y - %前推电压 1 A4 ~# d O; a9 D
- for j=2:n
8 b' h& Q! m! l i - U(1,3*k-2)=1.02;
! m; o3 f( v9 X3 s% @1 U8 H( z - U(1,3*k-1)=1.02*(sin(2*pi/3)+j*cos(2*pi/3));
Y3 \2 r* r7 ?/ P3 }2 {# e N - U(1,3*k)=1.02*(sin(4*pi/3)+j*cos(4*pi/3));
0 J' S7 {$ P) N" m - a=DB(j-1,2);
, _) b, K0 ^. M- i1 q, y% i8 ? - if DB(j-1,6)==1
! q: D, u3 b; O$ u% j - Yi=1/DB(j-1,4)*eye(3);
2 Q# N: y; t" a, | - G1=[IKi(a,3*k-2) IKi(a,3*k-1) IKi(a,3*k)]';3 ^1 p- n5 X! g! u2 R, ]6 B
- G=[U(a,3*k-2) U(a,3*k-1) U(a,3*k)]'-DB(j-1,4)*eye(3)*(G1-0.5*Yi*[U(a,3*k-2) U(a,3*k-1) U(a,3*k)]');
p/ Q/ e/ J) c* @& d3 v q, \ - U(j,3*k+1)=G(1,1); 5 Z) {! ?) G; V# |- z
- U(j,3*k+2)=G(2,1);
O! N% P7 x6 J! M0 D5 H - U(j,3*k+3)=G(3,1); 5 x$ ]* O L3 `5 G1 i
- else7 b3 N4 T+ M9 k
- YT=1/real(DB(i,4))+j*(1/imag(DB(i,4)));: U7 h& ?3 g% p2 S) C3 W5 z8 ?
- YI=YT*eye(3);: i% h9 _' l1 ?2 z& i/ m1 b
- YII=YT*eye(3);
' y/ p9 K9 S# |0 t - YIII=-YT*eye(3);
0 I, r/ l7 X0 v- ]" _0 }# V - H=inv(YIII)*([IKi(a,3*k-2) IKi(a,3*k-1) IKi(a,3*k)]'-YI*[U(a,3*k+1) U(a,3*k+2) U(a,3*k+3)]');
1 i" V8 f1 T% p5 {; P; l0 G: | - U(j,3*k+1)=H(1,1);
" z+ p: x5 q6 k+ X5 P1 z - U(j,3*k+2)=H(2,1);1 C2 \2 c4 |0 [. T- {& b
- U(j,3*k+3)=H(3,1);+ H( j9 N3 h3 E% T) [8 g) a* |
- end
7 D2 d! o s5 ?8 t1 u - end
* N: W' e8 p# N4 a. q7 l - dU1=U(:,3*k+3)-U(:,3*k); ( B! u. c( G F! t
- dU2=U(:,3*k+2)-U(:,3*k-1); ) r& Y3 \0 w$ x! j& X, g+ U1 j
- dU3=U(:,3*k+1)-U(:,3*k-2);
! ^8 S6 {- g+ u* b& B - if (max(abs(dU1))<0.001&&max(abs(dU2))<0.001&&max(abs(dU2))<0.001) - I+ `. L0 K- D7 J+ O
- break; 2 d5 G9 m k' k. w3 G& U
- else
. r o' |% P6 N" d/ r5 L0 c - k=k+1;
* |- ^. l9 B- g* D2 \ - end 7 R- ? T! Y" z, ^
- end( s& f$ \; Q1 n: ?
- U. {& m4 X) x/ ^. J, W' |2 H8 Y
- IL
6 U* P1 i1 X0 ]7 |% z( ^) W5 Y( u9 m - IKj' @% c) _* f! C4 u! @
- IKi; P( {8 n5 L, H& U" B
- k% L J7 m! x/ C# ]% u
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