- A 3-phase, 5 kVA, 208 V, 4-pole, 60 Hz, star-connectedsynchronous generator has negligible stator winding resistance anda synchronous reactance of 8 Ω per phase at the rated terminalvoltage. The generator is connected in parallel to a 3-phase, 208V, 60 Hz infinite bus. All losses may be neglected.
a)Â Â Determine theexcitation voltage and the power angle when the machine isdelivering rated apparent power at 0.8 PF lagging.
b)Â Â If the field excitationis increased by 20 % without changing the prime mover power, findthe stator current, power factor, and reactive power supplied bythe machine.
c)Â Â With the fieldcurrent as in (a), determine the maximum power with which thegenerator can be supplied without losing synchronism? What are thecorresponding stator current and power factor at this maximum powercondition?
