On 03/09/2011 05:47 AM, Josepi wrote:
(top posting fixed)
"Tim Wescott" wrote in message
...
Well, yes, if the stars are aligned right. If you excite it with a
voltage, and turn it faster than its synchronous speed*, then it'll dump
current onto the line instead of sucking current from it. Older small-
time co-generation schemes did this, because maintaining synchronization
is _not_ trivial. Nowadays, it's mostly done with special inverters that
sense the voltage on the line and synchronize the current to the voltage.


Will a typical 3 ph motor throw out juice, if driven by a pony motor?


Current? maybe but it will be 90 degrees out of phase with the
voltage.

It is often stated as putting reactive power back into the supply.

Nope, sorry, you're just plain wrong.

Using induction machines as generators is an established -- if slightly
obscure -- practice. Real mechanical power is transformed to real
electric power. There are some inductive VARs, but there's real VARs, too.

But don't argue with me. Argue with the world wide web:

http://en.wikipedia.org/wiki/Induction_generator
http://www.aerostarwind.com/induction_generator.html
http://www.daviddarling.info/encyclo...generator.html
http://www.electrodynamics.net/docum...er_gen2002.pdf

(and all the myriad other pages that come up when you search on
"induction generator).

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html