Question

A 4-pole, 60Hz, three-phase synchronous motor with a synchronous reactance of 0.5 Ω is working at half load with torque of 20 N-m. Assume ??  = 120∠00 ? (phase voltage). When working at the full load, the equivalent field voltage is Ef = 100 V (phase voltage).

a) Draw the per-phase equivalent circuit and label the parameters (5 Points)

b) Determine the power consumed by the half load (5 Points)

c) Calculate the armature current and active power consumed, at full load (using ???? � as the reference). (5 Points)

d) Draw the phasor diagram of ?t , ?f , ?s?? and Ia (5 Points)

e) Compute the reactive power consumed by the motor and its power factor, at full load. (5 Points)

f) Calculate the minimum excitation current of the machine if ?? = 5?? (at full load). (5 Points)

Answer 1