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//CHAPTER 8- DIRECT CURRENT MACHINES
//Example 3
disp("CHAPTER 8");
disp("EXAMPLE 3");
//10 kW 250 V DC shunt generator
//VARIABLE INITIALIZATION
p_o=10*1000; //output of generator in Watts
v_t=250; //terminal voltage in Volts
N=1000; //speed in rpm
r_a=0.15; //armature resistance in Ohms
I_f=1.64; //field current in Amperes
rot_loss=540; //rotational loss in Watts
//SOLUTION
//solution (i)
I_l=p_o/v_t; //line current
I_a=I_l+I_f; // armature current
E_a=v_t+(I_a*r_a); //E_a=emf of generator
disp(sprintf("(i) The armature induced emf is %.2f V",E_a));
//solution (ii)
w=(2*%pi*N)/60; //in radian/sec
T_e=(E_a*I_a)/w;
disp(sprintf("(ii) The torque developed is %.2f N-m",T_e));
//solution (iii)
arm_loss=(I_a^2)*r_a; //armature loss
fld_loss=v_t*I_f; //field loss
tot_loss=rot_loss+arm_loss+fld_loss;
p_i=p_o+tot_loss;
eff=(p_o/p_i)*100;
disp(sprintf("(iii) The efficiency is %.3f %%",eff));
//END
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