Page 123 - Solutions Manual to accompany Electric Machinery Fundamentals

When this program is executed, the plot of armature current versus flux is

Note that if the flux variation started at less than 80% of full load flux, we would see the armature current
both fall and rise in a classic “V” curve. For example, if the flux varied from 65% to 100% of full-load
flux, the curve would be as shown below:

4-27. Two identical 2.5-MVA, 1200-V, 0.8-PF-lagging, 60 Hz, three-phase synchronous generators are
connected in parallel to supply a load. The prime movers of the two generators happen to have different
speed droop characteristics. When the field currents of the two generators are equal, one delivers 1200 A
at 0.9 PF lagging, while the other delivers 900 A at 0.75 PF lagging.
(a) What are the real power and the reactive power supplied by each generator to the load?
(b) What is the overall power factor of the load?

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