Newbie
Joined: 07/10/2005
Location: AustraliaPosts: 34
| Posted: 07:09am 20 Oct 2005 |
I dunno, I would have thought it would be the same load on the VAWT?
Those rough numbers above say it is.
If the RPM of the motor increases three fold, and the torque reduces by a third, then it's the same load?.
The load produced by the motor should be the same with both systems, since voltage is proportional to RPM and current is proportional to torque, ie, approx 15v@3.3A = 50W at 500rpm.
Anymore than 3.3A and yes, I'll need more wind.
The voltage may be even slighty higher because of less copper losses and the higher efficiency of the motor.
50W isn't an improvement I know, but its at a more useable voltage.
A bigger VAWT with more torque would produce more current.
The numbers I have crunched(here on paper) certainly look good, but maybe I'm missing something?.
I'm using brushed DC motor theory here, surely DC generators are just the reverse effects, similar properties?
Anyway, hope you dont think I'm being argumentative, I'm just trying to get a working model in my thick head before I commit too much money to it.
(unemployed)
I have almost finished a small test VAWT for a little motor I have here.
Its a Darrius/Savonius design, sized to suit the materials I had at hand, but should be enough for the small load.
I just need to make some bearing blocks, then attach the motor direct-drive for some measurements.
Then I need to sort out the gear/belt drive system, which may take a while due to my lack of machinery, but I'll post results of the DD as soon as I'm done!