2013Exam - Q2

clear;clc;

%setting values of Zeeeez :D
global w %i've used a global var to adjust it as i want :)
w=377;

%the zeez :D
Z1 = 20 + i*xl(12e-3); Z2 = 40 + i*xl(60e-3); Z3 = 10 + i*xl(50e-3);
Z4 = 50 - i*xc(10e-6); Z5 = 35 + i*xl(25e-3); Z6 = 60 + i*xl(30e-3);
Z7 = 25 - i*xc(12e-6); Z8 = 15 + i*xl(5e-3);  Z9 = 30 + i*xl(12e-3);
Z10 = 16 - i*xc(7e-6); Z11 = 50 + i*xl(15e-3);

%Setting the value of Zx :)
Zx = 20:1:250;

%Converting the Vmsin(wt) to complex :)
V1 = (340/sqrt(2))*(cos(pi)+i*sin(pi));
V2 = (340/sqrt(2))*(cos(-pi/2)+i*sin(-pi/2));
V3 = (340/sqrt(2));
V4 = (340/sqrt(2))*(cos(pi/2)+i*sin(pi/2));

%creating Z matrix
Z = [ Z1+Z2,-Z2,0,0,0,0,0;
    -Z2,(Z2+Z3+Z4),-Z4,0,0,0,0;
    0,-Z4,0,-Z5,0,0,0;
    0,0,-Z5,(Z11+Z5+Z6),-Z6,0,0;
    0,0,0,-Z6,0,-Z7,0;
    0,0,0,0,-Z7,(Z8+Z9+Z7),-Z9;
    0,0,0,0,0,-Z9,(Z9+Z10)];

%Creating V
V = [+V1;-V2;+V2;0;-V3;+V3;-V4];

%The loop :)
for k=1:length(Zx)
    Z(3,3)=Z4+Z5+Zx(k);
    Z(3,5)=-Zx(k);
    Z(5,3)=-Zx(k);
    Z(5,5)=Z6+Z7+Zx(k);

    I=inv(Z)*V;

    %this is the most important part :) focus that >> abs(I3-I5)^2 * Rx <<
    P(k) = (abs(I(3)-I(5)))^2 * real(Zx(k));

end
[maxPower,index]=max(P); %as usual

%printing the output
fprintf('Max power is = %10.3f Watt \n  and its Zx = %10.3f Ohm \n',maxPower,Zx(index));

plot(Zx,P);
xlabel('Zx Value');ylabel('Power Value');
grid;