The alternator was my first choice but i dont get this part:
Controlling the rotor current will also control the total output current
This is untrue, so as such meaningless. The voltage in the field (rotor)
controls the stator's voltage. Current is a factor of voltage and load.
Voltage is determined by exciton voltage. Frequency is determined by RPMs.
- as far as i know alternator has maximum voltage output of 17V and the
current is in range from 50 - 90A depending on alternator.
An automotive alternator has a maximum voltage of (perhaps 17 volts)
though that can vary from model to model.
You could do that with a car alternator, a 3 ph stepup transformer and 3
phase bridge at the other side.
- i agree with you but my goal is to have such generator that will give
upper defined output without additional transformers etc.
If you must restrict yourself to a self-contained package, then rewind
the stator (not the rotor!) Hint: you know (on disassembly) the number
of turns for 14 volts nominal, so simple math will give you a ball park
figure for the new windings. Oh, and new rectifiers will be needed with
highter voltage ratings. But, you can 'reduce' that high voltage output
to a lower voltage (say 14 volts) and perhaps even re-use the original
regulator!
E.g. if you spin it with constant RPM of let say 80 and if you keep this RPM
all the time, the output of the generator should be 200V / 2A.
Let's say 8000 RPM, a more realistic number... But no, it would only
stabilize the output frequency, not voltage. The regulator controls the
output voltage, not RPMs. The current is a factor of what the windings
can produce without overheating. Since a 100 amp alternator in an
automotive application can produce about 1400 watts (maximum, typically
they produce about half that) you should be able to generate about twice
the power you are asking for.
Sounds like homework to me. Aren't you meant to do that yourself?
- i will try to do it myself but if i fail then i need to pass the
specification to someone who is constructing such things.
I've given you clues to figure out how to do this as a practical
experiment. Being a university professor, I won't tell you how to do the
calculations, that was covered in class (if you are a student).
