Author Topic: Alternator Design for VAWT  (Read 807 times)

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windygen

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Alternator Design for VAWT
« on: July 25, 2008, 09:40:00 PM »
I do not have any hands-on experience yet short of building models, so this is MAJOR rookie speculation, so here goes.


From what I can gather from the folks that have been good enough to post their stories on this great discussion board, it seems that alternator design leans toward HAWTs where torque requirements at very low RPMs and and burning up a stator at high RPMs are considerable engineering considerations. What if torque at low RPM and spinning too fast simply were not an issue? Would the alternator be designed differently; for example using three wires of #15 in hand on nine coils with 12 magnets each side to reduce resistance. How far could you go given fewer constraints?

« Last Edit: July 25, 2008, 09:40:00 PM by (unknown) »

Flux

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Re: Alternator Design for VAWT
« Reply #1 on: July 26, 2008, 12:59:12 AM »
Yes alternator design leans towards HAWTS, they work and that is where energy is directed.


I can't follow the rest of your comments. To get any reasonable output out of an alternator that is not the size of a house you need to turn it as fast as possible.


The biggest problem of the alternators used for HAWTS is that they are much slower than alternators for virtually any other purpose. The slower it runs the larger it has to be and the more it will cost for a given output power. Torque will be higher the lower the speed (and the higher the power). I can't see what this has to do with things.


"Burning up stators at high rpms" what on earth is that about. If we had the option to increase the speed to much more normal figures then the power out before burn out would be vastly greater. It is the stupid High torque low speed thing designed for a VAWT that is in theory going to be the problem with burn out. In reality few VAWTs provide enough power to drive themselves let alone burn out the alternator, but get a decent one going in a storm with no method of control and you will not be free of the burnout problems.


Come on, alternator design is more than playing with wire size and number of turns.


Roughly if you halve the rotational speed you increase the material weight ( magnet and copper) by a factor of 4 for the same power so anything you do towards reducing speed is going to result in a larger and more costly machine for the same results.


If you want to really learn then try some hands on experience you will soon find out what it is all about. Wind power is full of compromises, nothing is simple and most factors seem to work backwards from other sources of power generation.


Flux

« Last Edit: July 26, 2008, 12:59:12 AM by Flux »

windygen

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Re: Alternator Design for VAWT
« Reply #2 on: July 26, 2008, 03:10:36 AM »
Wow! Thanks for setting me straight. My hands on is forthcoming. I appreciate the reality check!
« Last Edit: July 26, 2008, 03:10:36 AM by windygen »