DIY 1000 watt wind turbine

Step 2 Build the coil disk

We wound the nine individual coils, soldered them in a 3 phase wye configuration, and encased them in resin. We used 35 turns of 2 parallel strands of 14 gauge enameled (magnet) wire for 12 volts. Use 70 turns of single strand for 24 volts. # 3 phase diagram shown here shows 3 stator coils. each of those coils is actually 3 coils in series. coils 1,4, and 7 are series together, 2,5, and 8 are series together, and 3,6, and 9 are series together.

more details, see the following page 15 for the series star, 1-y diagram.

http://www3.telus.net/faheydumas/Wind_Turbine/Forum/AXIAL_FLUX_HowItWorks.pdf

Comments

[lecaonguyen]

Looks very professional, but achieve AC voltage before the rectifier is how much? and the treatment you how the absence of wind (low voltage). Please reply to the email [e-mail]

[sspence]

It's not professional, it's a backyard hack ;-)

The ac voltage is determined by the number of turns in the coils, and the wind speed vs. load. If the voltage is too low, the batteries do not charge.

[Mrdman2442]

By wiring the alternator in star you sacrifice some current output. My thought would be wire each phase separately to a bridge rectifier then combine the DC output from the 3 rectifiers in parallel. Is there something wrong with this idea?
I am building a vertical turbine with a savonius (starter) inner rotor and a larger H type main rotor on the same shaft. With this setup in low wind, below startup, the turbine will still be turning and by connecting the rectifiers in series I could get usefull voltage at low current. When the winds pick up the rectifiers will be switched back to parallel so the main rotor can kick in.
Is this possible, or is there some reason 3 phase is only wired in star or delta?

[Mrdman2442]

Do you have an idea of how feet of magnet wire you used? Thinking about useing aluminum wire as its cheaper but I need an idea of how many feet to buy as the weights are different.

[sspence]

aluminum doesn't handle current as well, so you'll need to derate accordingly. I used about 200' of wire, but that's dependent upon voltage and current needs.

[mcsk8rg]

why do you need to rectify teh current comming from the coils ??? you can just connect all the +ve n -ve terminals of the coils n you are done !

you can get current directly from ALL the coils all at once !

[sspence]

There are no + and - terminals on the coils. It's 3 phase AC. Diode bridge is necessary to convert to dc.

[ironman1234]

if i were to do this could i use 19 gauge wire? would i use the same amount of coils, turns, and magnets? and would i use the same n50 magnet or would i use a different size?

[sspence]

with lighter wire, there is an opportunity to over heat the coils and cause a fire if you pull too much current. Off the top of my head, you'll probably be limited to 30 amps or so.

[valiox]

Because I don't have enough money to buy big Neodymium magnets,I have a big question> What if I am using N50 type, but wich will be 9mm in diameter, and 5 mm height, and I will reduce the number of turns for every coil, so in that case I will increase the number of the magnets, and the number of the coils?

[sspence]

With that many changes, all I can say is have fun experimenting.

[bchurchman]

Gotta love a fellow tinkerer! Was looking at your other projects. What's a good weekend project without the Fire Department involved? LOL

[sspence]

The only time I had to call the fire department was when I was burning grass, and it got away from me. Embarrassing, as I was a member .....

[danlong]

One question.

What is the separation between the coil and the magnet face? I didn't see a stat on the field spread. I did note that the magnet has a 175 F max temp before damage and I have visions of a 100F plus day with the turbine cranking. How do the magnets stay "cooler" along with the coils themselves during power production?

[sspence]

It's between 1/8" and 1/4". The closer you can get it without touching, the more power you make. This is an open "air cooled" design. The magnets are spinning in the wind acting like little fan blades. Where do you get the 175F number? Neo's have a curie point of 310 to 400 C.

[yummy69]

hello, how are you all guys ?
Can i make thins thing with hard disk megnets because im unable to buy this shape and neodymium magnet. from my place. so i think hard disk magnets are neodymium magnets and they can be use for this procedure ? Can it be ?
i have 200 pieces so i can use them together/

[sweenig]

I don't think you can use hard drive magnets. These magnets are polarized one way on one end and the other on the other end. So, the flux lines would go in the upper face on one side, travel through the structural steel (and the magnet itself) and exit the upper face on the other side. Hard drive magnets are not typical magnets. I suppose, if you were able to arrange them properly, you would have alternating poles, but that seems really difficult.

[jmart90]

i definately want to built 12 of these, each with 3 blades 8 feet in length! can anyone give me tips for building these cheaply?? (under $300 american??)

[sspence]

It's more like $500 plus, with all new materials, not counting the tower. Scrounging wire and magnets, you could do it for less than $100.

[kalo02]

Hi there, i'm not sure if this has already been asked but I was wondering if there was a reason why you chose to do it in three phase AC and then rectify it instead of generating it as DC in the first place? Is it just so there's no need for a commutator?

[sspence]

That's one reason. With no brushes or slip rings, there's less maintenance.

[dpaiva]

Hi everyone. Please, I need some advise. I have these small 20mm rounded magnets (100pcs). They seam very strong. The thing is that they are so small, they get to far from one to other. Needless to say, I did not get any good voltage.

I am planning to use only 6 coils with about 300 turns and rectifying every single coil and then put then in series or parallel depending on the wind. 6 Magnet pieces together X 8 around each disk.

Does it make sense? Is there any problem rectifying each coil?

Also, I used some resin they use on cars that seams to interact with the magnet. I will find where to get this epox instead.
Thanks in advance

[sspence]

So, you are making a 6 phase machine, that would be 12 diodes, two per phase. you can't series alternate phases, but you could series two coils and make a 3 phase (1,2,1,2,1,2) then you would only need 6 diodes. resin is not magnetis. what do you mean "interact"?

[dpaiva]

Hi, thanks for the quick reply.

- Interact meaning it pulls or push the magnet, acting like one. I will look for other resin kind. When I say putting them into series, it would be after rectifying them (2 diodes per coil + capacitor).

- My concern on making it into phase is that since I have different magnets sizes I would not know how to perfectly mach the disposition of the coils X magnets. I did see on your pdf the ratio would be 1/1.333 though, but I just wanted to keep it simple to avoid more frustration. :)

Extra info: The magnets I got are 20mm diameter x 12mm height. 8 per disk. (Total 16 magnets blocks)
Each coil: 300 turns x 22awg = 40mm diameter. (Total 6 coils)

Hey, I really appreciate all your attention and help.

[sspence]

fiberglass resin is non magnetic. capacitor?

[dpaiva]

I did not use fiberglass in the first try. I used this thing they use to repair cars putting two products together so they get hard.

Capacitor would be this electronic component that evens up the wavy signal after the rectifier breaks the full alternated wave into positive and negative.

My main question rises on how to figure the size between the coils when I use different magnets sizes then yours. My concern is that the phases wont be matched if I don't do the right spacing on coils and magnets and so, I though that maybe, rectifying each coil separately, I would not have to worry about this. What do you think?

Thanks.

[sspence]

That would be Bondo. That works ok. The capacitor is not necessary. The batteries do not require it. if the phases are not matched, if the coils and magnets are not identical, this machine will not work.

[dpaiva]

Hum.. for some reason I am not able to add a message with an attachment.. Well, let me try again with a link only then.

Hi sir.

I've gave up on my last idea and went ahead searching for a maching 6 coils X8 Magnets (two rotors) 2 coils per phase. Based on the size of my magnets, I draw the image on the link below. Could you please, with your experience, take a look at it and see if it makes sense?

I measured one coil and it gave me 2.5v with one rotor.

Thanks again,.
Dan.

http://www.tutoringportalsystem.com/DanielPics/gen.jpg

[sspence]

Looks ok to me.

[schel]

All I gotta say is AWESOME!! well done!

the applications of this design are wide open!
2 of these -sans the blades...could easily gen a bunch -o-power on say,...a stationary bike...or heck a small lawnmower engine could spin a row of these ...make for Da' BomB camping gen

Thanks for sharin' yer info bro!

[hemang charaniya]

can you help me how can i built 10 mw wind power plant. you have any idea. plese help me i need you help.

[sspence]

mw, as in milliwatt? or MW, as in megawatt? No, I only build units in the 500 to 1000 watt range.

[menahunie]

Interesting post; but is it just to show everyone what you did? or show them how to duplicate what you did?
I have to go with the latter since you left out allot of build information.
The cost from doing this "project" cost vs. power output is far more than what I did.
I went to a junkyard found a 260 amp alternator ( $100)off an ambulance and mounted and attached a wind prop to it. I pulled the voltage regulator and used a Sevcon unit for control. I used #4 welding cable with soldiered terminals to take the alt. output directly from the rectifiers. For charging the batteries using a HF ( high Freq. battery charger is best ). There is more electronics for the out put to the house etc..
You can also use the motor from a treadmill; you see them all the time on someone's curb they are throwing out...
I included some math about windturbines:
Power AVAILABLE in the wind = .5 x air density x swept area x (wind velocity cubed)

Example: air density = 1.23 kg per cubic meter at sea level. Swept area = pi x r squared. Our 2 foot blades = 0.609m, 4 ft = 1.219m. 10 mph = 4.4704 m/s, 20 mph = 8.9408 m/s.

How much power is in the wind: 2 ft blade, 10 mph winds = .5 x 1.23 x 3.14 x 0.609squared x 4.4704 cubed

= .5 x 1.23 x 1.159 x 89.338 = 63.7 watts

With 4 foot blades and 10 mph winds = .5 x 1.23 x 4.666 x 89.338 = 256 watts

With 4 foot blades and 20 mph winds = .5 x 1.23 x 4.666 x 714.708 = 2051 watts

That's the MAXIMUM power in the wind. However, it's impossible to harvest ALL the power. The Betz Limit tells us that the maximum percentage of power we can harvest from the wind is 59.26%.

Thus our maximum power from these turbines would be:

2 ft blades, 10 mph wind = 37.7 watts

4 ft blades, 10 mph wind = 152 watts

4 ft blades, 20 mph wind = 1,215 watts


In parting even the motor from a direct drive washing machine can and is used for a wind generator; the design is very similar to what you show everyone in your posting. All I am trying to comment about is allot of people may not have the time or ability to duplicated what you did.

[sspence]

We documented what we did, and tried to show how to do it with enough detail that anyone can duplicate.

4 ft. blades in 10 mph winds can only output about 60 watts.

4 ft. blades in 20 mph winds can only output about 500 watts. No way can it do 1200 watts.

http://www.green-trust.org/windpowercalc/eindex.html

[ashbranmeg]

Did you alter the polarity of your magnets? If not, wouldnt the output of your generator be DC with no need for a rectifier? If there is no alternating of the field, there will be no reversing of the flow? That means DC not AC?

[Seminumerical]

Coils can only generate electricity in an alternating magnetic field.  Hence, you always get AC when using coils.  I have never heard of anything generating DC using magnets, without a rectifier.  But DC can be generated with solar PV-cells, peltier-elements or chemically with batteries.  Another source for AC is piezo-elements which generates current when sqeezed.

[ashbranmeg]

I dont wish to start a long drawn out discussion on electrical theory here, but you are incorrect. A coil will move electrons any time a magnetic fiel is passed across it. AC is generated when a magnet is spun with first the north pole moving electrons in one direction then the south pole in the opposite direction and so on.

If you design a generator where only the north pole of your "field" passes through the coil you will generate dc. Granted it will be pulsating dc. You clean up the pulses by having enough coils to fill in any "gaps".

Many homebuilt wind turbines use permanent magnet DC motors, because they are designed with rotataing magnets that operate in this very way. Most DC permanent magnet motors when spun will produce DC voltage that can be connected directly to your charge controller.

To say that you can generate only DC with a coil is incorrect.

[staida]

These "gaps" are a sawtooth wave. It's still a waveform, you haven't rectified that current thus you still require a rectifier. Calling it dc when it's still one side of an AC wave (in that pesky theory you wanted to avoid) doesn't earn you any points.

[ashbranmeg]

"sawtooth wave"? I am assuming you mean pulsating DC. This wind generator would presumably be used to charge a bank of batteries that would be providing power for an inverter. What you dont seem to know is pulsating DC is used quite frequently to charge batteries. I called it Dc because that is exactly what it is, be it pulsating DC. I am not interested in "earning points", but rather am trying to point out that it is not necessary to rectify pulsating Dc to charge a battery. Most store bought automotive battery chargers use pulsating DC to charge batteries, I would recommend doing some research before claiming that pulsating DC is not useable in this application.

[sspence]

This wind generator does not produce dc. it produces 3 phase ac. A rectifier (6 diodes) is necessary to convert it to dc for battery charging.