1、班級 姓名 學號、作業要求編寫程序計算圖1所示算例系統的潮流及三相短路電流。潮流計算：方法不限，計算系統的節點電壓和相角。短路電流：4號母線發生金屬性三相短路時（Zf=O）,分別按照精確算法和近似算法計 算短路電流、系統中各節點電壓以及網絡中各支路的電流分布，并對兩種情況下的計算結果進行比較。、電路圖及參數793支路R( p.u.)X (p.u.)B/2(Tk)( p.u.)1400.05761.02700.06251.03900.05861.0450.010.0850.088460.0170.0920.079570.0320.1610.153690.0390.170.179780.00850

2、.0720.0745890.01190.10080.1045表2 9節點系統發電機參數發電機編號節點類型Pg （ p.U.）Vg（ p.u.）xd （ p.u.）E* （ p.u.）1平衡1.040.31.1372PV1.631.0250.31.2113PV0.851.0250.31.043表3 9節點系統負荷參數節點編號節點類型P （ p.u.）Q（ p.u.）4PQ005PQ1.250.56PQ0.90.37PQ008PQ10.359PQ00三、計算步驟(i)進行系統正常運行狀態的潮流計算，求得 Ui(0)(2)形成不含發電機和負荷的節點導納矩陣Yn； 將發電機表示為電流源Ii (二Ei

3、/ jxdi)和導納yi( = 1/ jxdi)的并聯組合；節點負荷用恒阻抗的接地支路表示；形成包括所有發電機支路和負荷支路的節點導納矩陣Y,即在Yny和負荷導納 yLD i（yLD,iH Di - jQLDi中的發電機節點和負荷節點的自導納上分別增加發電機導納)； 利用Z =y，計算節點阻抗矩陣，從而得到阻抗矩陣中的第f 列; 利用公式(6-7)或(6-10)計算短路電流;利用公式（6-8）或（6-11）計算系統中各節點電壓;利用公式（6-9）計算變壓器支路的電流;對輸電線路利用n型等值電路計算支路電流。四、計算結果節點導納矩陣Yn：Columns 1 through 50 -17.3611

4、i000 +17.3611i000 -16.0000i000000 -17.0648i000 +17.3611i003.3074 -39.3089i-1.3652 +11.6041i000-1.3652 +11.6041i2.5528 -17.3382i000-1.9422 +10.5107i000 +16.0000i00-1.1876 + 5.9751i00000000 +17.0648i00Columns 6 through 9000000 +16.0000i000000 +17.0648i-1.9422 +10.5107i0000-1.1876 + 5.9751i003.2242 -15

5、.8409i00 -1.2820 + 5.5882i02.8047 -35.4456i-1.6171 +13.6980i00-1.6171 +13.6980i2.7722 -23.3032i-1.1551 + 9.7843i-1.2820 + 5.5882i0-1.1551 + 9.7843i2.4371 -32.1539i電壓幅值：1.04001.02501.02501.02580.99561.01271.02581.01591.0324電壓相角：0 0.16200.0814-0.0387-0.0696-0.06440.06490.01270.0343節點有功：0.71641.63000.8

6、5000.0000-1.2500-0.9000-0.0000 -1.0000-0.0000節點無功：0.27050.0665-0.10860.0000-0.5000-0.3000-0.0000-0.3500-0.0000修正后的節點導納矩陣 Y:Columns 1 through 50 -20.6944i000 +17.3611i000 -19.3333i000000 -20.3982i000 +17.3611i003.3074 -39.3089i-1.3652 +11.6041i000-1.3652 +11.6041i3.8716 -17.6627i000-1.9422 +10.5107i0

7、00 +16.0000i00-1.1876 + 5.9751i00000000 +17.0648i00Columns 6 through 9000000 +16.0000i000000 +17.0648i-1.9422 +10.5107i0000-1.1876 + 5.9751i004.1321 -16.0184i00-1.2820 + 5.5882i02.8047 -35.4456i-1.6171 +13.6980i00-1.6171 +13.6980i3.7323 -23.6669i-1.1551 + 9.7843i-1.2820 + 5.5882i0-1.1551 + 9.7843i2.

8、4371 -32.1539i節點阻抗矩陣Z的第4列：0.0463 + 0.1252i0.0329 + 0.0693i0.0316 + 0.0707i0.0552 + 0.1493i0.0589 + 0.1204i0.0562 + 0.1226i0.0397 + 0.0838i0.0416 + 0.0814i0.0378 + 0.0845i精確計算結果：短路電流：模值：6.4459相角：-71.9365節點電壓模值：0.14660.15060.45370.44630.44950.18310.56870.54270.0000支路電流：i jIij1 40.5779-3.1264i2 71.3702

9、-1.4433i3 90.64294-1.4808i4 5-0.77968+1.5248i4 6-0.6411+1.477i5 7-0.89528+1.6436i6 9-0.73353+1.5487i7 80.50734+0.10234i8 90.062766+0.056451i近似計算結果：短路電流：模值：6.2838相角：-69.7198節點電壓模值：0.42170.16110.52140.51570.00000.18270.16750.42270.4348五、程序流程圖六、程序及輸入文件input_data.xls 文件:Sheetl9節點系統支路參數首節點編號i尾節點編號 jR( p.

10、u.)X ( p.u.)B/2( p.u.)1400.057602700.062503900.05860450.010.0850.088460.0170.0920.079570.0320.1610.153690.0390.170.179780.00850.0720.0745890.01190.10080.1045Sheet29節點系統發電機及負荷參數節點編號節點類型P( p.u.)Q( p.u.)U( p.u.)Xd( p.u.)E( p.u.)1平衡1.040.31.1372PV1.631.0250.31.2113PV0.851.0250.31.0434PQ005PQ-1.25-0.56PQ

11、-0.9-0.37PQ008PQ-1-0.359PQ00powerflow_cal.m 文件：l=9;%支路數n=9; %節點數m=6; %PQ節點數Yn=zeros( n);%初始化節點導納矩陣 YDATA1=xlsread( 'in put_data.xls',1);%計算節點導納矩陣Yfor k=1:li=DATA1(k,1);j=DATA1(k,2);R=DATA1(k,3);X=DATA1(k,4);B2=DATA1(k,5);Yn (i,i)=Y n( i,i)+1i*B2+1/(R+1i*X);Yn (j,j)=Y n(j,j)+1i*B2+1/(R+1i*X);

12、Yn( i,j)= Yn (i,j)-1/(R+1i*X);Yn (j,i)= Yn (j,i)-1/(R+1i*X);enddisp('節點導納矩陣Yn :');disp(Y n);G=real(Y n);B=imag( Yn);,2);DATA2=xlsread('in put_data.xls'P=zeros(1, n);Q=zeros(1, n);U=on es(1, n);P(2: n)=DATA2(2: n,3);Q(4: n)=DATA2(4: n,4);U(1:3)=DATA2(1:3,5);%設置節點電壓初值e(1)=DATA2(1,5);e(

13、2: n)=1.0;f(1: n)=0.0;%設置迭代次數t=0;tmax=10;while t<=tmax%計算f(x)a(1: n)=0.0;c(1: n)=0.0;for i=2: nfor j=1: na(i)=a(i)+G(i,j)*e(j)-B(i,j)*f(j); c(i)=c(i)+G(i,j)*f(j)+B(i,j)*e(j);endendfor i=2: ndeltaP(i)=P(i)-e(i)*a(i)-f(i)*c(i);endfor j=4:ndeltaQ(j)=Q(j)-f(j)*a(j)+e(j)*c(j);endfor k=2:3deltaU2(k)=U(

14、k)*U(k)-e(k)*e(k)-f(k)*f(k); endfx=deltaP(2: n) deltaQ(4: n) deltaU2(2:3)'%計算雅克比矩陣Jfor i=2: nfor j=2: nif i=jH(i,j)=-(G(i,j)*e(i)+B(i,j)*f(i);N(i,j)=B(i,j)*e(i)-G(i,j)*f(i);elseH(i,j)=-a(i)-(G(i,i)*e(i)+B(i,i)*f(i); N(i,j)=-c(i)+(B(i,i)*e(i)-G(i,i)*f(i);endendendfor i=4: nfor j=2: n if i=j M(i,j

15、)=B(i,j)*e(i)-G(i,j)*f(i); L(i,j)=G(i,j)*e(i)+B(i,j)*f(i); elseM(i,j)=c(i)+(B(i,i)*e(i)-G(i,i)*f(i); L(i,j)=-a(i)+(G(i,i)*e(i)+B(i,i)*f(i);endendendfor i=2:3for j=2: nif i=jR(i,j)=0;S(i,j)=0;elseR(i,j)=-2*e(i);S(i,j)=-2*f(i);endendL(4: n,2: n);R(2:3,2: n)endJ=H(2: n,2: n)N(2: n,2: n);M(4: n,2: n)S(2

16、:3,2: n);if max(abs(fx)<0.0001%輸出結果break ;else%求解修正方程獲得dxdx=-JA(-1)*fx;dx=dx'e(2:n )=e(2: n)+dx(1: n-1);f(2: n)=f(2: n)+dx( n: 2*( n-1);t=t+1;endendif t>tmaxstr= '潮流計算不收斂'disp(str);elsea(1: n)=0.0;c(1: n)=0.0;for i=1: nfor j=1: na(i)=a(i)+G(i,j)*e(j)-B(i,j)*f(j); c(i)=c(i)+G(i,j)*f

17、(j)+B(i,j)*e(j);endendfor i=1: nU(i)=e(i)+1i*f(i); amp(i)=abs(U(i);arg(i)=a ngle(U(i);P(i)=e(i)*a(i)+f(i)*c(i);Q(i)=f(i)*a(i)-e(i)*c(i);enddisp('電壓幅值：)；disp(amp);disp('電壓相角：)；disp(arg);disp('節點有功：)；disp(P);disp('節點無功：)；disp(Q);end%計算短路電流f=4;zf=0.0;%修正節點導納矩陣Xd=DATA2(1:3,6);E=DATA2(1:3

18、,7);for i=1:3Ii(i)=E(i)/(1i*Xd(i);endY=Yn;for i=1:3Y(i,i)=Y(i,i)+1/(1i*Xd(i);endfor j=4:nY(j,j)=Y(j,j)+(-P(j)+1i*Q(j)/(U(j)*U(j); enddisp('修正后的節點導納矩陣Y:');disp(Y);Z=YA(-1);disp('節點阻抗矩陣Z的第4列：)； disp(Z(:,4);%精確計算disp('精確計算結果：);UO=U;lf=UO(f)/(Z(f,f)+zf);amp=abs(lf);arg=ata nd(imag(lf)/real(lf);di