 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Windmills : My first turbine
| Author | Message | ||||
WindyMiller Regular Member  Joined: 05/04/2011 Location: United StatesPosts: 62 |
Hi all, I am working my doing my first wind turbine and I have a few questions for those who can help with the design stage of my project? What I would like to accomplish is this I bought a three phase AC 3/4 HP induction motor for #10 at the local flea market. The motor is a tri voltage 208, 220, 415. The motor is a 1725-1425 RPM machine rated for continous duty as a blower motor. I want to use a steel tripod or maybe a 4 legged tower 8 feet in the air. The tower I am thinking of using is from one of the those garden decoration wind turbines as I like the looks of them, and I do not have the ability to weld so making a tower would be alot of trouble. The blades I am totally confused on where to start, or how to go about the construction of them? I am looking for a three blade prop with the blades from tip to hub being 4 feet. Other than that, I do not know where to start on this subject? I have also considered a 12 blade water pumping mill blade design so in the summer the machine would be turning maybe with the slight breeze we get if any. Most of the summer we see little wind. The motor I took apart to see about adding magnets when I discovered the rotor has 8 or so holes through the center. What I am wondering is if I where to put round bar magnets in a N, S, N, S arrangement two holes being N two being S all the way around which would give my 4 poles total since the machine is a 4 pole motor. If I used a gear box could I do a induction generator hybrid where the magnets helped to energize the machines capacitors at slow speed and maybe stablize the output? Anyone know why this would or would not work? The gear box I have in mind is 300 RPM in and 1800 RPM out. The winds where I live usually do not get above 5 to 10 MPH except windy days when the weather is changing. Or when we get 60 or 70 MPH gust in a thunderstorm. The problem is that without a drill press I don't have any way of drilling into the rotor like I have seen some articles talk about on here. This is the motor below. 
I am looking for 12 volts at maybe 5 amps as my inverter and batteries are 12 volts and 5 amps because I don't think the winds could do much more than that. Robert |
||||
| WindyMiller Regular Member Joined: 05/04/2011 Location: United StatesPosts: 62 |
This is the set of articles that got me thinking of the hybrid induction generator ideas. Link1 Link2 I personally believe my idea mentioned in the post above would work. The only real concern is with locking the rotor. Other than that I don't see why inserting the magnets in the center would not do something? Robert |
||||
MacGyver Guru  Joined: 12/05/2009 Location: United StatesPosts: 1329 |
WindyMiller Welcome to the 4m. I culled this from your Link 1: "Unlike induction generators (IGs), the PM generators can be built with large diameters and high pole numbers." Looking at your picture, your core diameter is about 3 or 4 inches. You'll not likely create much (any) useable electricity unless you run it at higher rpms than a slow-turning windmill moves. A water-pumping mill that uses what I call a compression blade will turn relatively slowly even in a hard wind. My hunch is, depending on your magnets' clearance to the iron core, it will lock up and be nearly impossible to start spinning even with a blade of 8 foot diameter in a low wind. With a blade that big, you'd better have a way to stop it if it gets itself into a blow! Your concept is on track, but it would be worth your while to puruse this 4m and see what's already been done by others; see what works and what doesn't. Don't waste much time looking at my input as I've got a track record of creating fancy paper weights. Still, there is a plethora of more-clever folks here and lots of good ideas for a first wind turbine. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
||||
| WindyMiller Regular Member Joined: 05/04/2011 Location: United StatesPosts: 62 |
Mac, I wish Sparweb was still present around here as he was one of the induction motor experts. I have seen other induction motor conversions of different kinds done so I believe that it can be done somehow? I am considering a gear box to stepup the windspeed but I wonder how you calculate the ratios? Robert |
||||
| WindyMiller Regular Member Joined: 05/04/2011 Location: United StatesPosts: 62 |
Incase I am confusing anyone here this photo shows what I had in mind. The round bar magnets I am considering putting down the center as not to cut into the induction bars. The machine in theory would be a hybrid generator. Mainly induction with caps but also using the magnets to provide excitation and stablize the machine somewhat. I am thinking this one needs to be tested with a petrol engine to see what happens? 
Robert |
||||
 Print this page |
