1、IRB=I(1)-I(2);fprintf(the current through R3 is %8.4f Amps n,IRB)U4=I(2)*8;U7=I(3)*2;the source through R4 is %8.4f V n,U4)the source through R7 is %8.4f V n,U7)结果:the current through R3 is 0.3571 Amps the source through R4 is 2.8571 V the source through R7 is 0.4762 V(2)Z= -12 -12; 0 18;V=-16; 6;I(
2、3)=0.5;U=I(1)*20-I(3)*12;the source is %8.4f V n,U)i3=I(1)-I(3);i7=I(2);,i3)the current through R7 is %8.4f Amps n,i7)结果the source is 14.0000 V the current through R3 is 0.5000 Amps the current through R7 is 0.3333 Amps2求解电路里的电压,例如V1,V2,V5Y = 1 -1 2 -2 0; 0 5 -13 8 0; 2 0 4 -11 0; 176 -5 5 -196 0; 0
3、 0 0 0 1;I = 0 -200 -120 0 24;V = inv(Y)*I;V1=%fVnV2=%fVnV3=%fVnV4=%fVnV5=%fVn,V(1),V(2),V(3),V(4),V(5)仿真结果:V1=117.479167VV2=299.770833VV3=193.937500VV4=102.791667V V5=24.000000V3已知R1=R2=R3=4,R4=2,控制常数k1=0.5,k2=4,is=2,求i1和i2Z = 1 0 0 0; -4 16 -8 -4; 0 0 1 0.5; 0 -8 4 6;V = 2 0 0 0I = inv(Z)*V;i1 = I
4、(2)-I(3);i2 = I(4);i1=%f Ani2=%f An,i1,i2)i1=1.000000 Ai2=1.000000 A实验总结1、仿真前需进行准确的计算,列出节点或回路表达式方可列出矩阵惊醒计算。2、熟练矩阵运算公式,即:V=inv(Y)*I实验二 直流电路(二)1加深对戴维南定律,等效变换等的了解。2进一步了解MATLAB在直流电路的应用。1 在图2-3,当RL从0改变到50K,绘制负载功率损耗。检验当RL=10K的最大功率损耗。R=10;U=10;RL=10;P=U2*(RL*1000)/(R+RL)*1000)2RL=0:50;p=(RL*1000*U./(R+RL)*
5、1000).*U./(R+RL)*1000)figure(1),plot(RL,p),grid程序运行结果:P = 0.0025p = Columns 1 through 7 0 0.0008 0.0014 0.0018 0.0020 0.0022 0.0023 Columns 8 through 14 0.0024 0.0025 0.0025 0.0025 0.0025 0.0025 0.0025 Columns 15 through 21 0.0024 0.0024 0.0024 0.0023 0.0023 0.0023 0.0022 Columns 22 through 28 0.002
6、2 0.0021 0.0021 0.0021 0.0020 0.0020 0.0020 Columns 29 through 35 0.0019 0.0019 0.0019 0.0018 0.0018 0.0018 0.0018 Columns 36 through 42 0.0017 0.0017 0.0017 0.0016 0.0016 0.0016 0.0016 Columns 43 through 49 0.0016 0.0015 0.0015 0.0015 0.0015 0.0014 0.0014 Columns 50 through 510.0014 0.00142 在如图所示电路
7、中,当R1取0,2,4,6,10,18,24,42,90和186时,求RL的电压UL,电流IL和RL消耗的功率。A=3/4 -1/2 0; 1/2 -33/24 5/6; 0 1 -1;I=15 0 0U=inv(A)*I;us=U(3);R=6;Z=0 2 4 6 10 18 24 42 90 186;RL=Z(1,:),i=us./(R+RL)u=us.*RL./(R+RL)p=(RL.*us./(R+RL).*us./(R+RL)figure(1),plot(RL,i),gridfigure(2),plot(RL,u),gridfigure(3),plot(RL,p),gridRL =
8、0 2 4 6 10 18 24 42 90 186i = 8.0000 6.0000 4.8000 4.0000 3.0000 2.0000 1.6000 Columns 8 through 10 1.0000 0.5000 0.2500u = 0 12.0000 19.2000 24.0000 30.0000 36.0000 38.4000 42.0000 45.0000 46.5000 0 72.0000 92.1600 96.0000 90.0000 72.0000 61.4400 42.0000 22.5000 11.62501、经过这次实验基本了解了MATLAB变量生成的应用。2、
9、经过这次实验更加深刻了戴维南等效电路的原理。3、了解了MATLAB中图像的生成。实验三 正弦稳态1学习正弦交流电路的分析方法。2学习MATLAB复数的运算方法。1、如图所示电路,设R1=2,R2=3,R3=4,jxl=j2,-jXC1=-j3,-jXC2=-j5,Us1=80V,Us2=60,Us3=0,Us4=150,求各电路的电流相量和电压向量。clear,format compactR1=2;R2=3;R3=4;ZL=2*j;ZC1=-3*j;ZC2=-5*j;US1=8;US2=6;US3=8;US4=15;Y1=1/R1+1/ZL;Y2=1/ZC1+1/R2;Y3=1/R3+1/ZC
10、2;a11=1/Y1;a12=1/Y2;a13=1/Y3;a21=0;a22=-1;a23=1;a31=-1;a32=1;a33=0;b1=0;b2=US2/R2-US3/R3-US4/ZC2;b3=-US1/ZL-US2/R2;A=a11,a12,a13;a21,a22,a23;a31,a32,a33;B=b1;b2;b3;I=inv(A)*B;I1=I(1),I2=I(2),I3=I(3),ua=I1/Y1,ub=I3./(-Y3),I1R=ua/R1,I1L=(US1-ua)./ZL,I2R=(US2-ua+ub)/R2,I2C=(ua-ub)./ZC1,I3R=(US3-ub)/R3,
11、I3C=(US4-ub)./ZC2I1 = 1.2250 - 2.4982iI2 = -0.7750 + 1.5018iI3 =-0.7750 - 1.4982iua = 3.7232 - 1.2732iub = 4.8135 + 2.1420iI1R = 1.8616 - 0.6366iI1L = 0.6366 - 2.1384iI2R = 2.3634 + 1.1384iI2C = 1.1384 - 0.3634iI3R = 0.7966 - 0.5355iI3C = 0.4284 + 2.0373i2、含电感的电路:复功率如图,已知R1=4,R2=R3=2,XL1=10,XL2=8,XM
12、=4,Xc=8,Us=100V,Is=100A.求电压源,电压源发出的复功率。R1=4;R2=2;R3=2;XL1=10;XL2=8;XM=4;XC=8;US=10;IS=10;Y1=1/R1+1/(-j*XC);Y2=1/(j*(XL1-XM);Y3=1/(j*XM);Y4=1/(j*(XL2-XM)+R2);Y5=1/R3;a11=1;a12=-1;a13=0;a14=0;a15=0;a22=0;a23=0;a24=1;a25=-1;a31=0;a33=-1;a34=-1;a35=0;a41=1/Y1;a42=1/Y2;a43=1/Y3;a44=0;a45=0;a51=0;a52=0;a5
13、3=-1/Y3;a54=1/Y4;a55=1/Y5;A=a11,a12,a13,a14,a15;a21,a22,a23,a24,a25;a31,a32,a33,a34,a35;a41,a42,a43,a44,a45;a51,a52,a53,a54,a55;B=-US/R1;-IS;0;0;I1=I(1);I2=I(2);I3=I(3);I4=I(4);I5=I(5);ua=-I1/Y1;ub=I3/Y3;uc=I5/Y5;Ii=US/R1+ua/R1;Pus=US*IiPis=uc*ISPus = 54.0488 - 9.3830iPis =1.7506e+002 +3.2391e+001i4
14、、正弦稳态电路,利用模值求解如图所示电路,已知IR=10A,Xc=10,并且U1=U2=200V,求XL。clearU2=200;IR=10;R=U2/IR;XC=10;U=200*exp(-150j*pi/180);200*exp(-30j*pi/180);I=(U-200)./(-j*XC);X=200./(I-10);XL=imag(X)XL =5.359074.6410学习了正弦交流电路的分析方法,初步了解了MATLAB向量图的绘制,虽然并不能说完全掌握,但是基本有了一定的了解。实验四 交流分析和网络函数1学习交流电路的分析方法2学习交流电路的MATLAB分析方法1求电流i1(t)和电
15、压uc(t)Z=10-j*7.5 -6+j*5; -6+j*5 10+j*3;U2=2*exp(pi*75*j/180);U=5; U2;I=ZU;Uc=-j*10*(I(1)-I(2);i1_abs=abs(I1);i1_ang=angle(I1)*180/pi;uc_abs=abs(Uc);uc_ang=angle(Uc)*180/pi;current I1,magnitude: %f n, i1_abs)current I1,angle in degree:%fn,i1_ang)voltage Uc,mangnitude:,uc_abs)voltage Uc,angle in degre
16、e:,uc_ang) 结果 0.597294 13.266138 3.202746 -28.9807862显示一个不平衡wye-wye系统,求相电压VAN,VBN和VCN。Ua=110;Ub=110*exp(pi*(-120)*j/180);Uc=110*exp(pi*120*j/180);Za1=1-j;Zb1=1-j*2;Zc1=1-j*0.5;Za2=5-j*12;Zb2=3-j*4;Zc2=5-j*12;Uan=Ua*Za2/(Za1+Za2);Ubn=Ub*Zb2/(Zb1+Zb2);Ucn=Uc*Zc2/(Zc1+Zc2);disp(Uan Ubn Ucn)幅值),disp(abs
17、(Uan,Ubn,Ucn)相角),disp(angle(Uan,Ubn,Ucn)*180/pi)ha=compass(Uan,Ubn,Ucn);set(ha,linewidth,3)Uan Ubn Ucn幅值 99.8755 76.2713 103.1342相角 -2.1553 -116.8202 116.9789了解运用MATLAB分析交流电路。实验五 动态电路1学习动态电路的分析方法2学习动态电路的MATLAB计算方法1、激励的一阶电路已知R=2欧姆,C=0.5F, 电容初始电压Uc(0+)=4V,激励的正弦电压Us(t)=Umcoswt,其中w=2rad/s。当t=0时,开关s闭合,求电
18、容电压的全响应,区分其暂态响应与稳态响应,并画出波形uc0=4;w=2;R=2;C=1;Zc=1/(j*w*C);dt=0.1;t=0:dt:10;us=6*cos(w*t);%Um=6T=R*C;ucf=us*Zc/(Zc+R);uc1=uc0*exp(-t/T);figure(1);subplot(3,1,1);h1=plot(t,ucf);grid,set(h1,2)subplot(3,1,2);h2=plot(t,uc1);grid,set(h2,2);uc=ucf+uc1;subplot(3,1,3);h3=plot(t,uc);grid,set(h3,2、二阶欠阻尼电路的零输入响应
19、如图所示的二阶电路,如L=0.5H,C=0.02F。初始值uc(0)=1V,iL=0,试研究R分别为1,2,3,10时,uc(t)和iL(t)的零输入响应,并画出波形。R=1L=0.5;R=1;C=0.02;uc0=1;iL0=0;alpha=R/2/L;wn=sqrt(1/(L*C);p1=-alpha+sqrt(alpha2-wn2);p2=-alpha-sqrt(alpha2-wn2);dt=0.01;1;num=uc0,R/L*uc0+iL0/C;den=1,R/L,1/L/C;r,p,k=residue(num,den);ucn=r(1)*exp(p(1)*t)+r(2)*exp(p
20、(2)*t);iLn=C*diff(ucn)/dt;figure(1),subplot(2,1,1),plot(t,ucn),gridsubplot(2,1,2)plot(t(1:end-1),iLn),gridR=2R=3R=4R=5R=6R=7R=8R=9R=101学习动态电路的分析方法。2了解MATLAB暂态电路的计算方法。实验六 频率响应1学习有关频率响应的相关概念2学习MATLAB的频率计算1、一阶低通电路的频率响应如图为一阶RC低通电路,若以Uc为响应,求频率响应函数,画出其幅频响应(幅频特性)H(jw)和相频的响应(相频特性)ww=0:0.2:4;H=1./(1+j*ww);fi
21、gure(1)subplot(2,1,1),plot(ww,abs(H),grid,xlabel(ww),ylabel(angle(H)subplot(2,1,2),plot(ww,angle(H)figure(2)subplot(2,1,1),semilogx(ww,20*log(abs(H)dBsubplot(2,1,2),semilogx(ww,angle(H)ylabel(a)线性频率响(b)对数频率响2、频率响应:二阶低通电路令H0=1,画出Q=1/3,1/2,1/2,1,2,5的幅频相频响应,当Q=1/2时,成为最平幅度特性,即在通带内其幅频特性最为平坦。for Q=1/3,1/2
22、,1/sqrt(2),1,2,5ww=logspace(-1,1,50);H=1./(1+j*ww/Q+(j*ww).2);subplot(2,1,1),plot(ww,abs(H),hold onsubplot(2,1,2),plot(ww,angle(H),hold onsubplot(2,1,1),semilogx(ww,20*log10(abs(H),hold onsubplot(2,1,2),semilogx(ww,angle(H),hold onendfigure(1),subplot(2,1,1),grid,xlabel(wabs(H)subplot(2,1,2),grid,xl
23、abel(angle(H)figure(2),subplot(2,1,1),grid,xlabel(3、频率响应:二阶带通电路H0=1;wn=1;for Q=5,10,20,50,100 w=logspace(-1,1,50); H=H0./(1+j*Q*(w./wn-wn./w); figure(1) subplot(2,1,1),plot(w,abs(H),grid,hold on subplot(2,1,2),plot(w,angle(H),grid,hold on figure(2) subplot(2,1,1),semilogx(w,20*log10(abs(H),grid,hold
24、 on subplot(2,1,2),semilogx(w,angle(H),grid,hold on4、复杂谐振电路的计算L1=0.75e-3;L2=0.25e-3;C=1000e-12;Rs=28200;L=L1+L2;R=R1+R2;Rse=Rs*(L/L1)2f0=1/(2*pi*sqrt(C*L)Q0=sqrt(L/C)/R,R0=L/C/R;Re=R0*Rse/(R0+Rse)Q=Q0*Re/R0,B=f0/Qs=log10(f0);f=logspace(s-.1,s+.1,501);w=2*pi*f;z1e=R1+j*w*L;z2e=R2+1./(j*w*C);ze=1./(1./z1e+1./z2e+1./Rse);subplot(2,1,1),loglog(w,abs(ze),gridaxis(min(w),max(w),0.9*min(abs(ze),1.1*max(abs(ze)subplot(2,1,2),semilogx(w,angle(ze)*180/pi)axis(min(w),max(w),-100,100),gridfh=w(find(abs(1./(1./z1e+1./z2e)50000)/2/
copyright@ 2008-2023 冰点文库 网站版权所有
经营许可证编号:鄂ICP备19020893号-2