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+//CHAPTER 3- THREE-PHASE A.C. CIRCUITS
+//Example 4
+
+disp("CHAPTER 3");
+disp("EXAMPLE 4");
+
+//VARIABLE INITIALIZATION
+v_l=866;                              //in Volts
+z_delta=177-(%i*246);                 //in Ohms
+z_wire=1+(%i*2);                      //in Ohms
+
+//SOLUTION
+v_ph=v_l/sqrt(3);
+z_star=z_delta/3;
+z=z_wire + z_star;
+I=v_ph/z;                             // I_na in rectangular form
+//I_na, I_nb and I_nc are same in magnitude and are the line currents for delta connection
+//I_na
+I_na=sqrt((real(I))^2+(imag(I))^2);   //I_na from rectangular to polar form  
+a=atan(imag(I)/real(I));              //angle in radians
+a=a*(180/%pi);                        //radians to degrees
+//I_nb
+I_na=sqrt((real(I))^2+(imag(I))^2);
+b=a-120;                              //lags by 120 degrees
+//I_nc
+I_na=sqrt((real(I))^2+(imag(I))^2);
+c=a-240;                              // lags by another 120 degrees ie.,240 degrees
+disp(sprintf("The line currents are %f A (%f degrees), %f A (%f degrees) and %f A (%f degrees)",I_na,a,I_na,b,I_na,c));
+
+
+//line current lags phase current by 30 degrees, hence (-30)
+//I_AB
+I_AB=I_na/sqrt(3);
+a1=a-(-30); 
+//I_BC
+I_BC=I_na/sqrt(3);
+b1=b-(-30);
+//I_AC
+I_AC=I_na/sqrt(3);
+c1=c-(-30);
+disp(sprintf("The phase currents are %f A (%f degrees), %f A (%f degrees) and %f A (%f degrees)",I_AB,a1,I_BC,b1,I_AC,c1));
+
+//converting z_delta from polar form to rectangular form
+z=sqrt((real(z_delta))^2+(imag(z_delta))^2);
+angle=atan(imag(z_delta)/real(z_delta));
+angle=angle*(180/%pi); 
+
+//line voltages for load or phase voltages for the delta load-
+//v_AB
+v_AB=I_AB*z;
+a2=a1+angle;
+//v_B
+v_BC=I_BC*z;
+b2=b1+angle;
+//v_AC
+v_AC=I_AC*z;
+c2=c1+angle;
+disp(sprintf("The phase voltages for the delta load are %f A (%f degrees),  %f A (%f degrees) and %f A (%f degrees)",v_AB,a2,v_BC,b2,v_AC,c2));   
+
+p_AB=(I_AB^2)*real(z_delta); 
+p_load=3*p_AB;   
+disp(sprintf("The power absorbed by the load is %f W",p_load));
+p_l=3*(I_na^2)*real(z_wire);
+disp(sprintf("The power dissipated by the line is %f W",p_l));
+p=p_load+p_l;
+disp(sprintf("The total power supplied by 3-ϕ source is %f W",p));
+
+//Answers may be slightly different due to precision of floating point numbers
+
+//END