武大电气matlab电路仿真实验报告.docx

1、武大电气matlab电路仿真实验报告实验一：直流电路1电阻电路的计算程序：1电阻电路的计算第1题%本题选用回路法，列出的方程为Z*I=U的形式，求出回路电流，然后进一步求解Z= 20 -12 0; %阻抗矩阵 -12 32 -12; 0 -12 18;U=10 0 0; %电压向量I=inv(Z)*U; %回路电路向量i3=I(1)-I(2); %求i3u4=I(2)*8; %求u4u7=I(3)*2; %求u7fprintf(1) i3= %8.4fAn u4= %8.4fVn U7= %8.4fVn,i3,u4,u7)us=10/u4*4; %根据电路线性性质，由上题的u4变化的倍数求出u

2、sUb=us 0 0; %变化后的电压向量Ib=inv(Z)*Ub; %变化后的回路电流向量ib3=Ib(1)-Ib(2); %变化后的i3ub7=Ib(3)*2; %变化后的u7fprintf(2) us= %8.4fVn i3= %8.4fA n U7= %8.4fVn,us,ib3,ub7)输出结果：(1) i3= 0.3571A u4= 2.8571V U7= 0.4762V (2) us= 14.0000V i3= 0.5000A U7= 0.6667V2、 求解电路里的电压程序：%导纳矩阵AA= 0.6 0.125 -0.125 -0.1 0 -5 0 1 -1 0 0 0 0 -

3、10 0 -0.125 0.325 -0.2 0 0 0 0 0 1 -1 0 0 5 -0.1 0 -0.2 0.55 -0.25 0 0 0 0 0 0 1 0 0 1 0 0 -1 0 -1 0;%电流矩阵BB=0 0 5 0 0 24 0;V=inv(A)*B;fprintf(V(1)=%f VnV(2)=%f VnV(3)=%f VnV(4)=%f VnV(5)=%f Vn,V(1),V(2),V(3),V(4),V(5);输出结果：V(1)=117.479167V(2)=299.770833V(3)=193.937500V(4)=102.791667V(5)=24.0000001

4、求解含有受控源的电路里的电流程序：%A为阻抗方程A= 0 0 1 0 0 0 4 0 -4 12 -4 -4 -4 0 0 -4 8 0 0 0.5 0 0 0 1 0 -1 0 0 1 0 -1 0 0 1 0 -1;B=2 0 0 0 0 0;%B为电压方程I=inv(A)*B;fprintf(i1= %.0f Ani2= %.0f An,I(1),I(2);输出结果：i1= 1 Ai2= 1 A实验二：直流电路（2）1 求最大功率损耗程序：A= 1 0 -1/10000 1/10000;is=0;B=10 isV=AB;Uoc=V(2);is=1;B=0 is;V=AB;Req=V(2)

5、-V(1)/is;Pmax=Uoc.2/(4.*Req)fprintf(The maximum power occurs at %f n,Req)fprintf(The maximum powerdissipation is %f W,Pmax)RL=0:50000;VL=10.*RL./(10000+RL);PL=VL.2./RL;figure(1),plot(RL,PL),grid输出结果：The maximum power occurs at 10000.000000 The maximum powerdissipation is 0.002500 W输出图形如下则从图上可验证当RL为1

6、0K时，最大功率约为2.5W2 求消耗的功率程序：A=1 0 0 0 -1/5 1/5+1/2+1/20 -1/2 0 0 -1/2 1/2+1/24+1/1.2 -1/1.2 0 0 -1/1.2 1/1.2;V1=inv(A)*75 0 0 0;Uoc=V1(4);is=1;V2=inv(A)*0 0 0 is;Req=V2(4)/is;RL=0 2 4 6 10 18 24 42 90 186;REQ=Req Req Req Req Req Req Req Req Req Req;B=REQ+RL;for i=1:1:10;UL=Uoc.*RL(i)/B(i);IL=Uoc./B(i);

7、PL=UL.*IL;fprintf(%2d),i);fprintf( RL= %6.0f ,RL(i);fprintf( IL= %6.3f A,IL);fprintf( UL= %6.3f V,UL);fprintf( PL= %6.3f Wn,PL);end输出结果：( 1) RL= 0 IL= 8.000 A UL= 0.000 V PL= 0.000 W( 2) RL= 2 IL= 6.000 A UL= 12.000 V PL= 72.000 W( 3) RL= 4 IL= 4.800 A UL= 19.200 V PL= 92.160 W( 4) RL= 6 IL= 4.000 A

8、 UL= 24.000 V PL= 96.000 W( 5) RL= 10 IL= 3.000 A UL= 30.000 V PL= 90.000 W( 6) RL= 18 IL= 2.000 A UL= 36.000 V PL= 72.000 W( 7) RL= 24 IL= 1.600 A UL= 38.400 V PL= 61.440 W( 8) RL= 42 IL= 1.000 A UL= 42.000 V PL= 42.000 W( 9) RL= 90 IL= 0.500 A UL= 45.000 V PL= 22.500 W(10) RL= 186 IL= 0.250 A UL=

9、46.500 V PL= 11.625 W实验三：正弦稳态1 求各支路的电流相量和电压相量程序：%设置变量R1=2;R2=3;R3=4;XL=2;XC1=3;XC2=5;Us1=8;Us2=6;Us3=8;Us4=15;%求阻抗Z1=(j*XL*R1)/(j*XL+R1);Z2=R2*(-j*XC1)/(R2-j*XC1);Z3=R3*(-j*XC2)/(R3-j*XC2);Y1=1/Z1;Y2=1/Z2;Y3=1/Z3;%导纳矩阵YY=Y1+Y2 -Y2 -Y2 Y2+Y3;%电流矩阵II=Us1/(j*XL)+Us2/R2 Us3/R3-Us4/(j*XC2)-Us2/R2;U=inv(Y

10、)*I;ua=U(1),ub=U(2),I1=ua*Y1,I2=(ub-ua)*Y2,I3=-ub*Y3,I1R=ua/R1,I1L=(ua)/(j*XL),I2R=-(ua-ub)/R2,I2C=-(ua-ub)/(-j*XC1),I3R=(ub)/R3,I3C=ub/(-j*XC2),compass(ua,ub,I1,I2,I3,I1R,I1L,I2R,I2C,I3R,I3C);输出结果：ua = 3.7232 - 1.2732i ub = 4.8135 + 2.1420i I1 = 1.2250 - 2.4982i I2 = -0.7750 + 1.5018i I3 = -0.7750

11、- 1.4982i I1R = 1.8616 - 0.6366i I1L = -0.6366 - 1.8616i I2R = 0.3634 + 1.1384i I2C = -1.1384 + 0.3634i I3R = 1.2034 + 0.5355i I3C = -0.4284 + 0.9627i 输出图形为：2 含互感的电路：复功率程序：%设置变量R1=4;R2=2;R3=2;XL1=10;XL2=8;XM=4;XC=8;US=10;IS=10;Z1=R1*(-j*XC)/(R1-j*XC);Z2=j*(XL1-XM);Z3=j*XM;Z4=j*(XL2-XM)+R2;Z5=R3;Y1=1

12、/Z1;Y2=1/Z2;Y3=1/Z3;Y4=1/Z4;Y5=1/Z5;%导纳矩阵YY=Y1+Y2 -Y2 0 -Y2 Y2+Y3+Y4 -Y4 0 -Y4 Y4+Y5; I=US/R1 0 IS; U=inv(Y)*I; ua=U(1);ub=U(2);uc=U(3); i1=(US-ua)/R1; Pus=US*conj(i1), Pis=uc*conj(IS) 输出结果：Pus = -4.0488 - 9.3830iPis = 1.7506e+02 + 3.2391e+01i3 正弦稳态电路：求未知参数程序：US=100;I1=0.1;P=6;XL1=1250;XC=750;P=6;Z1

13、=j*XL1;Z2=-j*XC;cos_a=P/(US*I1);a=acos(cos_a);I1=0.1*exp(-a*1i);UL1=I1*Z1;UC2=US-UL1;IC2=UC2/Z2;IL3=I1-IC2;ZL=UC2/IL3;IC2=UC2/Z2;IZ3=I1-IC2;Z3=UC2/IZ3R3=real(Z3)XL3=imag(Z3)输出结果：Z3 = 7.5000e+02 + 3.7500e+02iR3 = 750.0000XL3 = 375.00004 正弦稳态电路，利用模值求解程序:%变量初始化syms XL;U2=200;IR=10;XC=10;R=U2/IR;%解方程的语句

14、f=R*XL-sqrt(XC*XL)2+R*(XL-XC)2);XL=solve(f,XL);XL1=XL(1)XL2=XL(2)输出结果：XL1 = 20*3(1/2) + 40XL2 = 40 - 20*3(1/2)实验四：交流分析和网络函数1 求解电流和电压程序：%本程序计算回路电流I1，I2%Z是阻抗矩阵，U是电压向量，I是电流矩阵Z=10-7.5i -6+5i -6+5i 16+3i;Zc=-10i;U1=5;U2=-2*exp(75i*pi/180);U=U1 U2;I=ZU;I1_abs=abs(I(1);I1_ang=angle(I(1)*180/pi;Ic=I(1)-I(2)

15、;Uc=Ic*Zc;Uc_abs=abs(Uc);Uc_ang=angle(Uc)*180/pi;fprintf(current I1,magnitude: %f n current I1,angle in degree:%fn,I1_abs,I1_ang);fprintf(voltage Uc,magnitude: %f n voltage Uc,angle in degree:%fn,Uc_abs,Uc_ang);运行结果：current i1,magnitude: 0.387710 current i1, angle in degree: 15.019255 voltage vc,mag

16、nitude: 4.218263 voltage vc,angle in degree:-40.8616912 求解三相不平衡相电压程序：%U为电压矩阵，I为电流矩阵，Z为总阻抗矩阵，ZL为负载阻抗矩阵U1=110;U2=110*exp(-120i*pi/180);U3=110*exp(120i*pi/180);U=U1 U2 U3;Z1=6+13i 4+2i 6-12.5i;ZL=5+12i 3+4i 5-12i;I=U./Z1;Vn=I.*ZL;Vna_abs=abs(Vn(1);Vna_ang=angle(Vn(1)*180/pi;Vnb_abs=abs(Vn(2);Vnb_ang=an

17、gle(Vn(2)*180/pi;Vnc_abs=abs(Vn(3);Vnc_ang=angle(Vn(3)*180/pi;fprintf(phasor vlotage Vna,magnitude:%f n phasor voltage Vna,angle in dgree: %f n,Vna_abs,Vna_ang);fprintf(phasor vlotage Vnb,magnitude:%f n phasor voltage Vnb,angle in dgree: %f n,Vnb_abs,Vnb_ang);fprintf(phasor vlotage Vnc,magnitude:%f

18、n phasor voltage Vnc,angle in dgree: %f n,Vnc_abs,Vnc_ang);运行结果：phasor vlotage Vna,magnitude:99.875532 phasor voltage Vna,angle in dgree: -2.155276 phasor vlotage Vnb,magnitude:122.983739 phasor voltage Vnb,angle in dgree: 93.434949 phasor vlotage Vnc,magnitude:103.134238 phasor voltage Vnc,angle in

19、 dgree: -116.978859实验五：动态电路1 正弦激励的一阶电路程序： %变量初始化R=2;C=0.5;Uc0=4;Um=10;Ulong=Um;%作图t=0:0.01:20;time=R*C;Uct=Ulong+(Uc0-Ulong)*exp(-t/time);figure(1),plot(t,Uct),grid运行结果：2 二阶欠阻尼电路的零输入响应程序：L=0.5;R=1;C=0.02;%输入元件参数Uc0=1;IL0=0;alpha=R/2/L;wn=sqrt(1/(L*C);%输入给定参数p1=-alpha+sqrt(alpha-wn2);%方程的两个根p2=-alpha

20、-sqrt(alpha2-wn2)dt=0.01;t=0:dt:1; %设定时间组%用公式Uc1=(p2*Uc0-IL0/C)/(p2-p1)*exp(p1*t);%Uc的第一个分量Uc2=-(p1*Uc0-IL0/C)/(p2-p1)*exp(p2*t);%Uc的第二个分量IL1=p1*C*(p2*Uc0-IL0/C)/(p2-p1)*exp(p1*t);IL2=-p2*C*(p1*Uc0-IL0/C)/(p2-p1)*exp(p2*t);Uc=Uc1+Uc2;IL=IL1+IL2;%分别画出两种数据曲线subplot(2,1,1),plot(t,Uc),gridsubplot(2,1,2)

21、,plot(t,IL),grid运行结果：R=1R=2R=3R=4R=5R=6R=7R=8R=9R=10实验六：频率响应1 一阶低通电路的频率响应程序：ww=0:0.2:4;%设定频率数组 ww=w/wcH=1./(i+j*ww);%求复频率响应figure(1)subplot(2,1,1),plot(ww,abs(H),%绘制幅频特性grid,xlabel(ww),ylabel(angle(H)subplot(2,1,2),plot(ww,angle(H),%绘制相频特性grid,xlabel(ww),ylabel(angle(H)figure(2) %绘制对数频率特性subplot(2,1

22、,1),semilogx(ww,20*log10(abs(H)%纵坐标为分贝grid,xlabel(ww),ylabel(分贝)subplot(2,1,2),semilogx(ww,angle(H)%绘制相频特性grid,xlabel(ww),ylabel(angle(H)运行结果：2.频率响应：二阶低通电路程序：for Q=1/3,1/2,1/sqrt(2),1,2,5 ww=logspace(-1,1,50);%设无量纲频率数组ww=w/w0 H=1./(1+j*ww/Q+(j*ww).2);%求复频率响应 figure(1) subplot(2,1,1),plot(ww,abs(H),h

23、old on subplot(2,1,2),plot(ww,angle(H),hold on figure(2) subplot(2,1,1),semilogx(ww,20*log10(abs(H),hold on%纵坐标为分贝 subplot(2,1,2),semilogx(ww,angle(H),hold on%绘制相频特性endfigure(1),subplot(2,1,1),grid,xlabel(w),ylabel(abs(H)subplot(2,1,2),grid,xlabel(w),ylabel(angle(H)figure(2),subplot(2,1,1),grid,xlab

24、el(w),ylabel(abs(H)subplot(2,1,2),grid,xlabel(w),ylabel(abs(H)运行结果：3 频率响应：二阶带通电路程序：clear,format compactH0=1;wn=1;for Q=5,10,20,50,100 w=logspace(-1,1,50);%设频率数组w H=H0./(1+j*Q*(w./wn-wn./w); figure(1)%横坐标为线性坐标 subplot(2,1,1),plot(w,abs(H),grid,hold on %绘制幅频特性 subplot(2,1,2),plot(w,angle(H),grid,hold

25、on %绘制相频特性 figure(2) subplot(2,1,1),semilogx(w,20*log10(abs(H),grid,hold on %纵坐标为分贝 subplot(2,1,2),semilogx(w,angle(H),grid,hold on %绘制相频特性end运行结果：复杂谐振电路的计算程序：clear,format compactR1=2;R2=3;L1=0.75e-3;L2=0.25e-3;C=1000e-12;Rs=28200;L=L1+L2;R=R1+R2;Rse=Rs*(L/L1)2%折算内阻f0=1/(2*pi*sqrt(C*L)Q0=sqrt(L/C)/R

26、,R0=L/C/R;%空载Q0值Re=R0*Rse/(R0+Rse)%折算内阻与回路电阻的并联Q=Q0*Re/R0,B=f0/Q,%实际Q值和带通s=log10(f0);f=logspace(s-.1,s+.1,501);w=2*pi*f;%设定计算的频率及范围及数组z1e=R1+j*w*L;z2e=R2+1./(j*w*C);%等效单回路中量纲电抗支路的阻抗ze=1./(1./z1e+1./z2e+1./Rse);%等效回路中三个支路的并联阻抗subplot(2,1,1),loglog(w,abs(ze),grid%画对数幅频特性axis(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/pi;%求回路阻抗大于50千欧的频带fhmin=min(fh),fhmax=max(fh)运行结果：