//CHAPTER 7- SINGLE PHASE TRANSFORMER
//Example 3

disp("CHAPTER 7");
disp("EXAMPLE 3");

//VARIABLE INITIALIZATION 
v1=2300;                             //primary voltage in Volts
v2=230;                              //secondary voltage in Volts
f=50;
R1=0.286;
X1=0.73;
R_dash_2=0.319;
X_dash_2=0.73;
Rc=250;
Xphi=1250;
Zl=0.387+0.29*%i;
//
//SOLUTION 
Z_e1=(R1+R_dash_2)+(X1+X_dash_2)*%i;
Z_dash_l=(v1/v2)^2*Zl;
// 
I_dash_1=v1/(Z_dash_l+Z_e1);
//[mag,angle]=rect2pol(real(I_dash_1),imag(I_dash_1));
//disp(sprintf("The  current is %f <%f  A",mag,angle));
//impedance of shunt branch
Zm=Rc*(Xphi*%i)/(Rc+Xphi*%i);
//[mag,angle]=rect2pol(real(Zm),imag(Zm));
//disp(sprintf("The  Zm is %f <%f  A",mag,angle));
I0=v1/Zm;
//[mag,angle]=rect2pol(real(I0),imag(I0));
//disp(sprintf("The  I0 is %f <%f  A",mag,angle));
//
//primary current
I1=I0+I_dash_1;
function [mag,angle]=rect2pol(x,y);
mag=sqrt((x^2)+(y^2));            //z is impedance & the resultant of x and y
angle=atan(y/x)*(180/%pi);      //to convert the angle from radians to degrees
endfunction;
[mag,angle]=rect2pol(real(I1),imag(I1));
theta1=angle;
disp("SOLUTION (i)");
disp(sprintf("The primay current is %f%f  A",real(I1),imag(I1)));
disp(sprintf("The primay current is %f <%f  A",mag,angle));
//
//input power
Pin=v1*I1; ;                            //=I1.cos(theta1)
disp(sprintf("The  input power is %f W",Pin));
//output power
V_dash_2=I_dash_1*Z_dash_l; 
[mag,angle]=rect2pol(real(V_dash_2),imag(V_dash_2));
theta2=angle;
disp(sprintf("The  V_dash_2 is %f <%f  A",mag,angle));
//
Pout= V_dash_2*I_dash_1;                //I_dash_1.cos(theta1)
disp(sprintf("The  output power is %f W",real(Pout)));
Pc=v1*I0;                               //core loss
loss=Pin-Pout;
Pcu=loss-Pc;                            //copper loss
disp(sprintf("The  core loss is %f W",Pc));
disp(sprintf("The  copper loss is %f W",Pcu));
//efficiency
eff=Pout*100/Pin;
disp(sprintf("The  percent efficiency is %f W",eff));
disp(" "); 
// The answers from V_dash_2 calculation onward do not match with the book on page 7.21 and 7.22
//END