On 22 Jun 2005 13:46:10 -0700, wrote:

In "Motor/Generator Analysis Redux" I wrote, but nobody replied to:

SNIP
I have put a lot of money and time into this, and I want to give it my
best shot, but I don't want to whip a dead horse, so to say.


Frankly, I don't understand magnetics. At least not as I understand
resonance. I'm an amateur musician; I understand resonance and know a
little about phase shifts near the peak. I do understand that because
the slope of the curve is negative on the high-frequency (capacitative)

side of resonance, loading of the generator, within limits, will result

in additional power to meet the load.


But B x I makes my head spin. I'm fine in 3 dimensions. So I get some
of it. And I get that in the cylindrical coordinate system, B and I can

be locally orthogonal, and can vary in time, with phase shifts, while
being wrapped into a connected topology. I just don't feel that the way

I feel resonances. It's not intuitive.


Would replacing the rotor "windings" with copper wire or bus bar
(easy), and rewinding the stator with bigger wire (hard) have any
chance at all of working together by lowering the leakage inductance
and rotor resistance to allow resonance?


That's my best question; is there any hope at all?


This is a one-off demo, not a production prototype!


Yours,


Doug Goncz
Replikon Research
Falls Church, VA 22044-0394

You've been wading in pretty deep water - although, at first
sight a self excited squirrel cage alternator sounds like a simple
device they're a positive feedback system. They're so touchy that
they're pretty well only used by dedicated amateurs - I don't know of
a single commercial application.

Note - this refers only to SELF EXCITED alternators. The same
machine driven at over synchronous speed and connected to a power grid
works fine as an induction alternator and will feed back to the power
grid the equivalent of it's mechanical input power less its generation
losses. This works well in commercial wind power sytems.

I really don't think you'll have much luck unless you move to a
decent size 4 pole machine and even then I doubt that you'd be very
happy with the results. A small permanent magnet DC motor is soooo
much easier and cheaper!

I'm sorry if this is a bit disappointing but it's all useful
experience and, sadly, experience is usually gained the hard way. You
picked a very tough one for yor first project - better luck next time.

Jim