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Vertical air turbine

PostPosted: Sun Jul 04, 2010 1:36 pm
by noll farmer
Hi All

I live on a farm and have a huge dam wall next to the house. I have a few single and 3phase squirrel cage electric motors lying on the farm. Want to convert then to vertical wind generators.

At the moment my renewable energy is as follows:
24 x 600AH lead acid batteries
2kw of solar cells
6 KVA 48Volt inverter

Anybody has ideas on how to convert squirrel cage motors to generators????

Re: Vertical air turbine

PostPosted: Mon Jul 05, 2010 2:25 pm
by windgat
Hi there. First thing I would do is check the RPM vs voltage for those motors. Spin them using an electric drill, and somehow measure the RPM, and the output voltage. That will give you an idea of the design, and if you would need to gear up or not.

Re: Vertical air turbine

PostPosted: Mon Jul 05, 2010 8:44 pm
by noll farmer
Hi Windgat

I have this problem. All my squirrel cage motors use the inrush current to magnetize the rotor. If I energize the rotor using caps and rotate the motor about 100rpm above the normal operating speed it starts to generate. Catch is that operating speed is 1500rpm. Now way that I can gear it to run above 1500 rpm to start to generate.

I was hoping that somebody has changed the squirrel cage rotor with a permanent magnet rotor. Something like milling the rotor down to fit magnets onto the rotor.

Re: Vertical air turbine

PostPosted: Fri Jul 09, 2010 6:33 am
by Greystoke
noll farmer wrote:Anybody has ideas on how to convert squirrel cage motors to generators????
IMO, not feasible. A "squirel" cage motor has a squirel cage rotor, which are shorted loops of copper bar (wire?) These loops line themselves up to the magnetic field induced by the 3-phase electrical supply and because that field moves around, so does the rotor. Sorry if I appear to teach you how to suck eggs.
To turn these things into generators, you would (in theory) turn them inside out. ie: rotate the electro-magnet and keep the squirel cage stationery, but it would generate a very low voltage, due to the lack of windings on the rotor.

Re: Vertical air turbine

PostPosted: Sun Jul 11, 2010 8:25 pm
by windgat
Greystoke! :yay: Welcome back! Been a long silence from you.

Re: Vertical air turbine

PostPosted: Mon Jul 12, 2010 8:13 am
by Greystoke
Thanks. Been otherwise occupied. Can't attend to too many things at the same time these days, but . . . I have a renewed interest.

Re: Vertical air turbine

PostPosted: Mon Jul 12, 2010 8:23 am
by Greystoke
noil farmer wrote:I was hoping that somebody has changed the squirrel cage rotor with a permanent magnet rotor. Something like milling the rotor down to fit magnets onto the rotor.
I came across this site on the internet:(http://www.otherpower.com/otherpower_wind_alternators.html). Perhaps it will help. (see:Induction Motor Conversion Alternators)