Page 88 - Solutions Manual to accompany Electric Machinery Fundamentals

(a) How much field current is required to make the terminal voltage V (or line voltage V L ) equal to
T
13.8 kV when the generator is running at no load?

(b) What is the internal generated voltage E A of this machine at rated conditions?

(c) What is the phase voltage V of this generator at rated conditions?

(d) How much field current is required to make the terminal voltage V equal to 13.8 kV when the
T
generator is running at rated conditions?
(e) Suppose that this generator is running at rated conditions, and then the load is removed without
changing the field current. What would the terminal voltage of the generator be?
(f) How much steady-state power and torque must the generator’s prime mover be capable of
supplying to handle the rated conditions?

(g) Construct a capability curve for this generator.

Note: An electronic version of this open circuit characteristic can be found in file
Fig_p41_occ.dat, which can be used with MATLAB programs. Column
1 contains field current in amps, and column 2 contains open-circuit terminal
voltage in volts.
(a) If the no-load terminal voltage is 13.8 kV, the required field current can be read directly from the
open-circuit characteristic. It is 3.50 A.
(b) This generator is Y-connected, so I  I . At rated conditions, the line and phase current in this
L
A
generator is

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