Problem 1:
A 255V shunt motor has an armature resistance of 0.245 Ohm and a field resistance of 124.9 Ohm. At no load (1200 r/min), the motor draws a current of 2.041 A. At full load, the motor draws 54 A. What's the motor's full load speed (in r/min)?
Problem 2:
Write MATLAB program and plot speed (r/min) vs torque (N-m) characteristic of Example 8-2 when input current is varied from 20 to 500 A in steps of 10 A.
Bonus Problem:
A 240 V dc shunt motor runs at 820 rpm and takes armature current of 55 A. Find resistance to be added to the field circuit to increase speed to 1050 rpm at an armature current of 85 A. Assume flux proportional to field current. Armature resistance = 0.149 ohm and field winding resistance = 249.5 ohm.