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Homework Statement
(i) A star-connected, three-phase synchronous induction motor takes a current of 10 amps from a 415 volt supply at unity power factor when supplying a steady load. If the synchronous reactance is 5 ohms/phase and the resistance is negligible, draw the phasor diagram and calculate the value of the generated emf and the load angle.
(ii) If the excitation is reduced by 10% and, as a consequence the generated e.m.f. is reduced by 10%, calculate the new value of the generated e.m.f E, the stator current, the power factor and the load angle, assuming that the load does not change[/B]
Homework Equations
The Attempt at a Solution
For part (i) I have the emf calculated as 245V and the load angle as 11.6 degrees
I am struggling with part (i). I have the new emf at 220.5V but don't know where to go from there.
If I do the same equation for load angle as in part one it doesn't work.
Any help appreciated.