Magnets

[Windmill1]

Hello
I have a 10ft otherpower 48 volt system wind turbine.I plan in the summer to build a similar turbine using the same 48 volt stator, same blades, but I want to use 2x1x3/4 magnets instead of the 2x1x1/2 magnets that are on the rotors now. Will this work ok? Can I expect more power?
Thanks

[Flux]

Yes it will work but expect to open the air gap sufficiently to reduce the flux to that produced by the smaller magnets. Don't expect any more power with the same prop and stator, in other words the extra cost of magnet is not justified unless you happen to have them.

The only way you would gain is using the Classic mppt controller, if this is direct charging you will be limited by stall or stator heating.

Flux

[Windmill1]

Thanks
I think I need to wait and do some research before starting to build.

[john8750]

Flux,
I can see an advantage of using all power available with an MPPT circuit on 12 volt systems.
Can it also capture more charge on the 48 volt system?
I'm learning as I go here....

[Flux]

Yes it will work on any voltage system as long as the controller can stand an input of at least 3 times the battery voltage.

With 48v you will have only a modest line loss and the rectifier loss can be ignored so you may not expect such a magnificent gain near peak output but even a 48v machine will be running way off the peak of the props power curve except at one wind speed. For good balance with direct charging you won't be able to cut in to get the very low winds without hitting hard stall up the wind range. You will have to add the line loss in externally or include it in the stator loss to get a reasonable overall performance even with a modestly low cut in speed.

At 3 times cut in speed you will have 1/3 the stator current with mppt and the I^2R loss will be 1/9 with the mppt converter. In addition you gain by keeping the prop on ideal performance.

Flux