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// Example 4.6
// Determine (a) Power input (b) Total losses (c) Air gap power (d) Shaft speed
// (e) Power factor (f) Combined windage, friction and stray load loss
// (g) Shaft torque
// Page No. 159
clc;
clear;
close;
// Given data
Pshaft=74600; // Shaft power
eeta=0.910; // Rated efficiency
ns=1200; // Speed of stator
Pcore=1697; // Power in core
Pscl=2803; // Stator copper loss
Prcl=1549; // Rotor copper loss
fs=60; // Synchronous frequency
p=6; // Number of poles
Vline=230; // Line voltage
Iline=248; // Line current
// (a) Power input
Pin=Pshaft/eeta; // Parallel resistance
// (b) Total losses
Ploss=Pin-Pshaft;
//(c) Air gap power
Pgap=Pin-Pcore-Pscl;
// (d) Shaft speed
s=Prcl/Pgap; // Parallel resistance
ns=120*fs/p;
nr=ns*(1-s);
// (e) Power factor
Sin=sqrt(3)*Vline*Iline;
FP=Pin/Sin;
//(f) Combined windage, friction and stray load loss
Closs=Ploss-Pcore-Pscl-Prcl;
//(g) Shaft torque
Tshaft=5252*100/nr;
// Display result on command window
printf("\n Power input = %0.0f W",Pin);
printf("\n Total losses = %0.0f W",Ploss);
printf("\n Air gap power = %0.0f W ",Pgap);
printf("\n Shaft speed = %0.0f r/min ",nr);
printf("\n Power factor = %0.2f ",FP);
printf("\n Combined windage, friction and stray load loss = %0.0f W ",Closs);
printf("\n Shaft torque = %0.1f lb-ft ",Tshaft);
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