前推回代法计算标准流程

前推回代法计算流程要看懂前推回代法计算程序，报告论述计算原理及计算流程。绘制计算流程框图。拟定前推回代支路顺序（广度优先，或深度优先），编写前推回代计算输入文献。进行潮流计算。下列为节点配电网构造图及系统支路参数和系统负荷参数表。图1-2 节点配电网构造图表1 系统支路参数支路R()X（.）B/2(TK) （S）123.3673.6850.0232.3562.5410.0341.1451.280.0454.5245.040.0260.8561.140.0672.7452.9650.0283.7434.2510.0892.2372.7560.03104.144.6960.03111.3281.7630.011122.4362.8660.04133.5213.9660.0表2 系统负荷参数节点编号节点类型节点初始电压（kV）Pi（MVA）Qi（MVA）1根节点10.4002中间节点10.00.03420.03013中间节点10.00.06930.06424中间节点10.00.08450.07635叶节点10.00.02950.02616中间节点10.00.04740.04097叶节点10.00.11760.09578中间节点10.00.09460.08579叶节点10.00.09160.085910叶节点10.00.02710.022911中间节点10.00.06960.064312叶节点10.00.06760.057913叶节点10.00.02980.0242主程序清单：PQ,FT,RX=case114(); %调用数据文献NN=size(PQ,1); %节点数NB=size(FT,1); %支路数数V=PQ(:,1); %V初始电压相量maxd=1k=1while maxd>0.0001 PQ2=PQ; %每一次迭代各节点旳注入有功和无功相似 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; %计算沿支路旳无功损耗/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旳有功P 单位MW PQ2(kt,3)= PQ2(kt,3)+PQ1(i,2); %用PQ1去修正支路末端节点旳有功Q 单位Mvar PL=PL+RX(i,1)*x;endangle(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); %计算支路电压损耗旳纵分量dv1 dv2=(PQ1(i,1)*RX(i,2)-PQ1(i,2)*RX(i,1)/V(kf); %计算支路电压损耗旳横分量dv2 V2(kt)=sqrt(V(kf)-dv1)2+dv22); %计算支路末端电压/kV angle(kt)=angle(kf)+atand(dv2/(V(kf)-dv1); %计算支路endmaxd=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 endmaxdk=k+1PQ1 %潮流分布 即支路首端潮流MVAV=V2 %节点电压模计算成果kVangle %节点电压角度计算成果单位度PL %网损单位MWendclear输入文献清单：function PQ,FT,RX=case114()PQ=%节点电压 有功 无功10.4 0 010.0 0.0342 0.030110.0 0.0693 0.064210.0 0.0845 0.076310.0 0.0295 0.026110.0 0.0474 0.040910.0 0.1176 0.095710.0 0.0946 0.085710.0 0.0916 0.085910.0 0.0271 0.022910.0 0.0696 0.064310.0 0.0676 0.057910.0 0.0298 0.0242;FT=%首端 末端 5 413 44 310 312 1111 37 66 29 88 23 22 1;RX=% R X 4.524 5.043.521 3.9661.145 1.284.14 4.6962.436 2.8661.328 1.7632.745 2.9650.856 1.142.237 2.7563.743 4.2512.356 2.5413.367 3.685;计算过程maxd = 1k = 1maxd = 0.1780k = 2PQ1 = 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 0.7260V = 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 9.9799angle = Columns 1 through 8 0 0.3011 0.3986 0.4211 0.4387 0.3421 0.3916 0.3878 Columns 9 through 13 0.4225 0.4173 0.4444 0.4747 0.4400PL = 0.0471maxd = 0.1787k = 3PQ1 = 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 0.7274V = 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 9.9470angle = Columns 1 through 8 0 0.3011 0.4011 0.4244 0.4421 0.3431 0.3929 0.3899 Columns 9 through 13 0.4257 0.4204 0.4486 0.4791 0.4434PL = 0.0484maxd = 0.1793k = 4PQ1 = 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 0.7277V = 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 9.7680angle = 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 0.4447PL = 0.0487maxd = 0.1226k = 5PQ1 = 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 0.7278V = 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 9.6457angle = 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 0.4452PL = 0.0487maxd = 0.0010k = 6PQ1 = 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 0.7278V = 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 9.6447angle = 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 0.4452PL = 0.0488maxd = 2.6021e-004k = 7PQ1 = 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 0.7278V = 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 9.6445angle = 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 0.4452PL = 0.0488maxd = 6.1046e-005k = 8PQ1 = 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 0.7278V = Columns 1 through 8 10.4000 9.8795 9.6991 9.6652 9.6377 9.8492 9.7872 9.7326 Columns 9 through 13 9.6870 9.6764 9.6578 9.6235 9.6444angle = 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 0.4452PL = 0.0488计算成果清单：maxd = 1k = 1maxd = 0.1780k = 2maxd = 0.1787k = 3maxd = 0.1793k = 4maxd = 0.1226k = 5maxd = 0.0010k = 6maxd = 2.6021e-04k = 7maxd = 6.1046e-05k = 8PQ1 = 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 0.7278V = 10.4000 9.8795 9.6991 9.6652 9.6377 9.8492 9.7872 9.7326 9.6870 9.6764 9.6578 9.6235 9.6444angle = 0 0.3011 0.4011 0.4250 0.4438 0.3431 0.3942 0.3899 0.4266 0.4209 0.4498 0.4823 0.4452PL = 0.0488 参照文献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.