Small wind generater project advise needed please?

[oztules]

Yes, you can use a car alternator ( or truck what ever ), but it is not generally done as it is a very difficult way  to do it.

If you design some interesting electronics to drive the rotor, and gear it up to a fan, you will probably have a useful device....

If you stretch your mind a bit, you must throw out the regulator for a start, as it will stall the mill. It will try to drive full power out straight away. This will cost you magnetizing current ( about 5A) and stall the blades the moment start up rpm is achieved.

If I had no choice, I would build a mppt rotor exciting device to replace the regulator, and chain drive it to a fan.  Press a small magnet into the rotor to get start up trickle for the electronics......This stands a chance of working..... but there are lots of better ways to do it.... mostly like everyone else does it. Matching the power of the blades to the load of the alternator is the key..... hence the complicated regulator you would have to design. You will also have the current to drive the rotor current to pencil into your calculations, but it is doable.

It is something most folks will leave alone, but it could ( with the right electronics) be a useful windmill, as you would be able to control the load to the blades, and solve the linear/squared/cubed problems associated with most mill heads. But is NOT simple at all.

Strongly advise against this route though for a newbie.

Perhaps try normal stuff first.



...................oztules

[Wolvenar]

Just fyI a standard alternator will not do the job well, or if at all. They have been used, with mods.. but even then there are certainly other off the shelf repurposed items that would work better, and much easier. Most can be had for little if any extra cost. I'm sure there are plenty of examples others here can name. Old tape drive motors come to mind. Ive seen some older wheelchair motors and such.

[oztules]

Once upon a time I would agree with that summation, but after working with them with my regulators, I'm not so sure.

They develop quite high current at quite low rpm.... typically 800 or so rpm will still keep up 5-10A into a 12v battery in low state of charge ( 11-12v), and thats a small one.

I think it just has not been done well previously. All attempts I have witnessed so far have not been done as I would do it. I think in a decent wind regime they would actually shine. Folks trying to get something in winds less than 12mph or so will be better with the axial flux units, but in 13 mph upwards, I think the humble stock car alternator ( minus the regulator, but with the three little diodes for the regulator supply left in tact ) would be found to be very competitive, and completely controllable..... something we cant do with perm magnet devices without buck and boost converters.

For folks without electronic design experience it will end in tears though....


............oztules

PS, if I had my stuff in a journal ( hint ), I think there is a story on alternator chargers, and possibly a regulator circuit that could be altered for this purpose. I think it is on this site.

EDIT: Yes it is on this site.... for those wanting a fairly detailed look at car alts, then

here: http://www.anotherpower.com/board/index.php/topic,492.0.html

and here: http://www.anotherpower.com/board/index.php/topic,500.0.html

And it looks like wolv is the only person to have read it too.

I suggest Dan read it as well.

That regulator is ok for human load matching with the volume control, but not for a windmill. I would probably start out with a TL494 and use the two op amps built in and the dead time control to effect an analogue mppt.. perhaps beat the frequency against the current in the two op amps ( different gains) and the dead time to soften the hysterisis... no ... I havent thought this through really, but I would start with this and see what happened.

[rossw]

PS, if I had my stuff in a journal ( hint )

Ye only had t' ever let us know you wanted one and it'd be done.
<waves magic wand>
There you go, Oz. Enthrall us with your wisdom sir!

[oztules]

Not quite Ross

You will find Wolv knows of the request.

Thanks for the journal, but as I asked Wolv, it needs to be populated with all the stories where i was the thread starter..... ie a journal with all my projects in the one place so i can find them, and direct folks to them.

Is your wand able to do that which this software is unable ( but scoop was).

....... oztules

[Watt]

OZ, I saw where the second thread was read 806 times and the first thread, 3286 times.  I hope you know a lot of us are paying attention and admire you and the time you have spent on your write-ups.  Thank you sir!

[Rover]

As far as the turbine and motor selection, the GE ECM motors 1/2hp to 1 HP are a good place to start. I have a few. So does Ghurd. You can sometimes find them on Ebay.

Fairly easy to use, minimum wiring work , and just use a bridge rectifier to your batteries. You may want to get one of Ghurd's controllers for a dump load, but for initial testing to batteries , probably not necessary

Rover

[Norm]

 Rover : "the GE ECM motors 1/2hp to 1 HP are a good place to start. I have a few. So does Ghurd"

Ah yes Indeed they are!
The one I have on the PedGen is one that Ghurd  sold to me .

A bit of overkill for the PedGen unless you are a gorilla !

but someday I'll use it on a windmill.

about 40 rpm of the pedalcrank  (1:8 ratio of the alternator) it charges a 12 volt battery
at about 25 watts with about as much effort as walking!

Norm.

[Rover]

Yeah I think he might still be mad at me for grabbing a 1 HP off of Ebay for like $25 a 2 years or so ago.... might have been a little more, my brain is a bit foggy.

This was a new one.

Its the only 1 HP I have, I have a few now seriously modified 1/2 and 3/4 HP ones.
They were used for experiments, documented elsewhere, along with treadmill motors etc. The ECM is still the best IMHO for a small wind turbine, if you understand what it's limits are and are content with a low power, small blade diameter, fast spinning turbine. They beat the commercial Air .. whatever model , hands down, but that is not saying much.

Rover

[WooferHound]

Thanks for the journal, but as I asked Wolv, it needs to be populated with all the stories where i was the thread starter..... ie a journal with all my projects in the one place so i can find them, and direct folks to them.

oztules
You can direct AnotherPower forum members to your journal but nonmember guests will not be able to see your journal

dan5160
Building a wind generator is not very difficult. I built a 200watt genny without any welding
http://www.anotherpower.com/board/index.php/topic,211.0.html

[rossw]

oztules
You can direct AnotherPower forum members to your journal but nonmember guests will not be able to see your journal

Woofer, we can actually set them to be whatever permissions are required.
I'm 99% sure I let oztules journals be read by anyone - even guests.
Would appreciate if someone would try it next time before they log in, or log out and check.

(Oz, if that's NOT what you want, better shoot me a message and say (eg) "I only want forum members to be able to read thanks!")

[oztules]

Yes, I write this dribble so others can read it. I don't want it to be secret that I'm a klutz.

Woof, thats a cool unit... but it only counts if you get it dirty..... is it up yet?
..........oztules

PS Sorry Dan, I have polluted your thread. My apologies

[bj]

  The second apology to Dan, but because Ross asked, I can see Oz's journal when I'm logged in,
or logged out.

[WooferHound]

Woof, thats a cool unit... but it only counts if you get it dirty..... is it up yet?

I built that 200w generator 10 years ago and it has never seen any wind. Right now it is out in a shed doing nothing. I am going through a divorce and will probably be moving soon. The new house is in a very bad wind location so I may have to make a pedal generator out of it.