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// Example 10.11
// Determine (a) Electrical losses (b) Rotational losses (c) Efficiency
// Page No. 430
clc;
clear;
close;
// Given data
T=124; // Hp rating of motor
Rf=32.0; // Field resistance
VT=240; // Rated voltade of the machine
IT=420; // Total current
Ra=0.00872; // Armature resistance
RipRcw=0.0038; // Resistance of interpolar winding and compensating windings
Pout=92504;
Vb=2.0; // Rated speed of the machine
Racir=Ra+RipRcw;
// (a) Electrical losses
If=VT/Rf; // Field current
Ia=IT-If; // Armature current
Pf=If^2*Rf; // Field power
Paipcw=Ia^2*(Ra+RipRcw);
Pb=Vb*Ia; // Brush loss power
Plosses=Pf+Paipcw+Pb; // Total power loss
// (b) Rotational losses
Ea=VT-(Ia*Racir)-Vb; // Armature emf
Pmech=Ea*Ia; // Mechanical power
Pshaft=T*746; // Shaft power
Protational=Pmech-Pshaft;
// (c) Ffficiency
eeta=Pout/(VT*IT)*100;
// Display result on command window
printf("\n Electrical losses = %0.1f W ",Plosses);
printf("\n Rotational losses = %0.0f W ",Protational);
printf("\n Efficiency = %0.1f Percent ",eeta);
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