multi stator wind generator

[frontpage32]

hi the dumb question guy again just about to order one of the books on the list provided in responce to my last post thank you but a was thinking all i ever see on this site is single stator well i have seen on or two split (rotor in middle) ones but there always wired together what i am wondering is well it always seems to be a compromise volts or amps .. can you get the best of both worlds i mean one stator wired for amps one for volts and then combine them some how to charge the same bank? ok i know dumb question ... or would it just be better to have several rotors and stators all wired the same to put out more .. of what ever you decide best?

also ... anyone know where you can find neodenium magnets in winnipeg manitoba and magnet wire so i can start one of the simple projects and start working from there .. i have seen ebay for wire but hoping to find a local source as don't like paypal much .. a pain in the butt well .. hope all is cool

[DanB]

This question seems to be coming up at least once a week now!  We need to write an FAQ on the topic for sure.

You can basically put multiple stators/magnet rotors on one shaft and get multiple times the power, or - you can put all those same magnets on 2 larger magnet rotors and all that copper on 1 larger stator and get multiple power x 2!

If you build two machines on the same shaft - 4 magnet rotors, 2 stators, you get twice the power as one.  If you build 1 larger diameter machine with the same materials you get 4x the power as one.

Unless diameter is an issue - multiple stators and magnet rotors make no sense.

[Flux]

Yes this has been covered a lot lately, although you ask it in a slightly different form.

Volts amps and watts are all tied up together, it is not possible to have one stator for volts and one for amps.

What you could do is to have 2 stators, one optimised for a good match in low winds and one matched for high winds. You would need some switching circuit to remove the low wind stator in high winds. This could work reasonably well but you are never using the whole of the stators or magnets effectively at any one time.

It becomes more sensible to use common magnets and have switched stator windings for the two conditions. The simplest of these schemes is star/delta but you could do it in more effective ways. Few people have done this, there are snags that are not immediately obvious, which can be overcome, but it removes a basic simplicity that most are afraid to depart from.

The virtues of multiple stators are limited and certainly as far as magnets are concerned it is far better to put all your magnets in a single larger diameter magnetic circuit.

What you propose is virtually using 2 alternators to cover different parts of the range and switching from one to the other. It has been done on large grid tie machines using induction generators but things are moving on from that concept.

Flux

[Adam T]

  If I understand his question correctly (as seen through the eyes of a newbie); and frontpage32 can correct me if I am wrong, he is asking if a dual stator gen. can be combined and used at the same time.  I believe Flux answered it quite simply.  Two stators wired differently can not be connected at the same time, as each will be producing differing outputs.  An analogy to that would be to have a vehicle with one wheel geared for speed, and one for torque, and wanting to use both at the same time.  Each one has merits of its own, on its own.

  And regarding using larger rotors, more magnets, and more coils per stator, as before, the explanation is spot on.  But I seem to recall someone comment (perhaps another forum) that they had several stators sitting around.  I don't want to risk hijacking the thread, so i will only suggest that if you wanted to research further on multi-stator, start and stick with 'like-wired' stators.  You could wire them in series to increase your voltage, or in parallel to increase your watts.

  If this were an existing machine you were to modify, you would be doubling the "work" you are giving the blades.  And as all parts of a machine affect each other, you would be inclined to do things like increase the swept area, etc... but modifying an existing machine in this way seems unlikely.

Thanks for the dumb question, and keep them coming.  I'll try to provide my share.  The things in life I learned the most from were my biggest mistakes.  And I have two older brother, who provided me with a wealth of wisdom.