Question

In a 50-kVA, star-connected, 440-V, 3-phasc, 50-Bz alternator, the effective armature resistance is 0.25ohm per phase. The synchronous reactance is 3 2 ohm per phase and leakage reactance is 0,5 ohm per phase. Determine at rated load and unity power factor:

(a) Internal e.m f. E_a (b) no-load e.m.f En (c) percentage 'emulation on full-load (d) value of synchronous reactance which replaces armature reaction.