Windmill design for a 20-30 HP 3 Phase Motor

[JaimesBeam]

I just found a surplus dealer who's going out of business

who will sell me five 3 Phase motors for a song. They

are between 20 and 30 HP sealed outdoor duty motors.

perfect for windmills.

Of course I need to come up with the rest of the design.

I don't know anything about prop design, and I need some

kind of gear box, or can I use an easy belt & pulley, even

if it isn't efficient?

I was guessing 20 to 30 ft diameter prop, maybe three blades...

What do you think?

I had Electrical Engineering a long time ago, so I'm hoping I

can figure out the electrical circuitry. I know that this needs

a grid tie-in to excite the generator. But I suppose Bangor

Hydro won't make a grid tie-in easy!

I was thinking about using a drilled well casing for the tower.

Having a well drilled down 50 ft should be a good anchor. Put

one or two smaller diameter pipes inside to slide up and down

to be able to raise and lower the tower... Add some guy wires

for stability...

We're on a great sit for wind power, on a north/south ridge

on the Maine Coast. It'd be great to take advantage of it!

I'd be glad to share my generator windfall for help with the design!

Any help would be appreciated!

Thanks,

Jim Baranski

Shalom Orchard & Winery

158 Eastbrook Rd Franklin ME 04634

One bit of information:

1. HP = 750 Watts so a motor designed to produce 20 HP could produce
   
15. KW.
    
1. HP = 750 Watts so a motor designed to produce 30 HP could produce
   
22. 5 KW.
    
    

This is a nice size wind turbine for me; enough to produce more then

enough

power for the farm, but not too big to be unmanageable.

This ignores efficiency losses.  A motor producing 20 HP requires

more then 15 KW

to produce it.  So is a motor (acting as a generator) being pushed by

20 HP is going to

procude less then 15 KW.  Can it be overdriven enough to produce more

without doing

a melt-down?

Jim

www.redrok.com/cimtext.pdf

Implies that 500 Watts per Horsepower is a better expectation.

That gives me 10 KW electrical power from a 20 HP motor.

That gives me 15 KW electrical power from a 30 HP motor.

Not too Bad...

The above document also gives the circuit diagram for connecting the

generator's

9 leads to a delta of large capacitors.  Three points are also

indicated where 110 VAC

can be output.

I will attempt to post the file to the group file library.

Jim.

[willib]

you may want to read about Mr Zubbly's exploits in the realm of motor conversions

just go to the front page and scroll down

everything is there , from skewing the stator , to circuit diagrams of windings, to the number and what magnets to use and how to position them

happy reading

[Countryboy]

1 HP is 746 watts, but a 20 HP motor DOES NOT produce 15KW, nor will a 30 HP motor produce 22.5KW.

They CONSUME this amount when they operate.  Motors won't produce their rated power consumption if you supply power at the shaft from a different source.

Can it be overdriven enough to produce more

without doing

a melt-down?

You will have to overdrive it just to get near the output you want.

You are thinking that someone can use a factory 3 phase motor as a generator with no modifications, and that's simply not the situation.  You will need to convert the motor into a generator by removing the stator, and building a new stator with permanent magnets.  It may also be necessary to rewire the motor completely.

Take a month or three to read all you can about motor conversions and wind generators.  Read all of zubbly's posts and diaries.

Motor conversions of this size will nto be quick and easy propositions.  Creating your own small wind farm will nto be a quick and easy proposition, nor will it be cheap.  Plan on spending thousands of dollars, and plan on it taking 20+ years to repay your investment.

You may be further ahead to get the motors for the song, and then sell them for the scrap copper wire in them.

[vawtman]

It would be cool to see someone follow these to conclusion.Variable pitch blades and the likes.

 What do you think would happen to a fixed blade when the speed is reached to ignite the gen and the load is introduced?

 Lots of thought is needed yet

 Wish best of luck to you.

[The Crazy Noob]

You CAN make a generator out of these babies and you DO NOT need to change anything about them.

The idea is so simple that I'm amazed that so few people know it. Just run the motor about 5% above it's syncronous speed (positive slip) and you will feed back into the grid. No expensive batteries needed! No expensive (grid-tie)inverter needed! No expensive (thick) cables needed! (it's all 120V/240V so low line resistance)

chech this topic: http://www.fieldlines.com/story/2006/7/2/8853/36057

[drdongle]

I'd like to make a point if I may. It seems obvious that you currently have little or no experience with wind turbines, at least with designing and building them. I recommend that you start small, and get some experience with a 1 or 2 HP motor conversion, tower, control and so forth, first. A 20-30 HP based machine will be extremely demanding physically and structurally. Just making blades for it will be a very big job.

[Sparky01]

Jim, I too agree that this is a very, very large turbine to start with. So far I have not tried a motor conversion, I guess because the dual rotor design seem to have been reseached a little more. Not that a motor conversion will not work as well. I have been wondering if there was anyone else in the state of Maine that was into homebrew wind tubines. I live in Unity, Maine. But Zubbly definitly seems to have the most experience when it comes to motor conversions.

[scottsAI]

Hello JaimesBeam,

My self and another are working on a 24' grid tied wind generator design. 15 HP to 30 HP.

Send me an email if your interested in the details and understanding why we are doing what were doing. Have fun,

Scott.

[TAH]

If someone is going to take 20 years to pay off the investment into a windmill that they build wouldn't it be much better to buy a commercial head at least. A 10 KW bergey cost about $20K with a grid tie controller and if he really had a good site it will output 1200 or more KWH per month. At the rate the power company here charges that would take about 11 years to pay off.

[The Crazy Noob]

"a eml dot cc"

I know that with the spam and all you should not put your email-adress in whole on a site, but I believe that your description is a bit too criptycal :-)

Is that: scottsai-@-eml-.-cc/com ??

[dinges]

Why not make it a diary so everyone can enjoy the progression of your system?

[scottsAI]

not .com the other is correct.

[scottsAI]

Hello dinges, thanks for the question.

More than willing to share, today mostly is just confirming how something works etc. been going slow for several months. Direction has changed as many times. The design is the most fun... Now the other is into building, so makes a good team. He also likes to design with his ideas. All part of the fun.

Project is a grid tied 24' blade, 10kw wind turbine, cost less than $6,000. Tower, gen, backup system, the whole thing.

Started with axial gen, then realized the power conversion at 10kw is big $. Looked for a different way. Then realized pitch control was easier than, and lower cost than the 10kw converter needed.

I learned this from post here. Realized how the big ones work is just what we needed.

Now plan is to use an induction motor 15-30hp (not sure of max wind speed) with control electronics with a direct feed into the grid! Blades not wood. May build a 3-5 hp version first to work out the bugs then on to the big one. Now with the induction gen the cost have come into line.

When we get it built and working will post design including why and what we did.

Maybe show the design before we build it to check what everybody thinks.

I have found answers to my questions without posting to date. Few months back I saw replies to post that prevented me from posting. Just not willing to take the crap, really bothers me. I deal with it in my job, not willing to for fun. Things have gotten much better lately, may post design, will think about it. What do you think?

Thanks,

Scott.

[The Crazy Noob]

I agree that posting a diary is better than doing it via email :-)

Have you already seen "Breezy 5.5 - A Reliable 5500 Watt Homebuilt Wind Turbine Generator"? Here's the link: http://www.prairieturbines.com/gglgatewy.htm . He sells books which describe the entire building proccess and he also sells the electronics to controll it. The blades are stall-regulated, not pitch-controlled like you are trying/going to do.

Good luck!

[scottsAI]

Thanks for the link Crazy Noob, back in the beginning had looked it over, forgot about it. Then was focused on an axial gen. Breezy design is interesting, along with using stall control. We have many hours a day and whole days with low winds, wanted max power, yet not willing to give up any in the higher winds. Figured would mess around with pitch control. If I can't find or figure out something then may very well fall back to the Breezy design. I look at cars and see some of the complicated systems they have gotten working on a budget, I figure so can I. Willing to use as many unmodified - slightly modified parts from vehicles as possible! Electronics for the control will be easy to design, making the control work will be interesting. Protection from lightning will be interesting. So there are a lot of interesting things going on. Keeps me from watching TV...

Have fun,

Scott.