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3 ph wind generator

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Amfuel

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Hi all, I'm a newbie here, I just found this place, I like good active forums, this looks to be a very active site. I think I'll enjoy it and I'm looking forward to browsing here regularly.

Here is the deal, I have a Fisher Pakel washer and when I tore it apart I realized it had a 3 phase dc motor in it. (I do things like that when I spot interesting things.) I decided to see if I can make a VAWT out of it. I have the outer tub cut to the base for the generator mounting and shaft, lower spin basket with balancing liquid that free wheels and the agitator that will provide a mount structure for savvy blades. This has really good bearings that are designed to take the abuse of out of balance loads. I built a stand for it and so far I have the machine cost of $9 and $0 in parts. The bad news is FP doesn't provide much of any tech info on the machine. The appliance industry if rather greedy about those things.

The motor - 3 phase brushles DC, 42 coil stator, 14 magnet rotor cover, 32 ohms between legs. I can generate 12vac at about 8-10 rpm and up to about 450vac when I run it up with a drill motor to top speed, about 800 rpm. I have no idea what the amperage output might be as I'm skittish to add a load to find out. I did add a small 12v motor and realized that it will run the motor at very low rpm across 2 legs.

My concern is the 3 ph wiring is only 20 ga and if I make this charge 12vdc It is going to overload the wiring. I'm thinking of using it at 48vdc as this will reduce the wiring heat and lower the amps output of the system. Of course I could run a higher voltage but then the rpm needs to be substantial and higher wind speed to generate. (Sorry, math is not my strong subject.)

I would like to just rectify it to dc for now and stabilize the voltage. Next year look into an inverter and controller for 120vac. Higher volt dc does bother me some so inverting at the outset is not out of the question.

I intend to try this out initially as a load for a hot water pre-heater with an exchanger to pre-heat the boiler water to help heat the house this winter and possibly add charging capabilities for a new garage and loft apartment that is under construction.

I would appreciate thoughts on the output design and what would be a good median voltage to strive for.

Thank you, Oscar
 
One solution to the higher voltage low amperage output problem would be to use the rectified three phase to produce a higher voltage DC then run that thought a switching power supply like one or more from a computer. Switching power supply's take the line voltage AC and then rectify it to DC and then use a high frequency inverter of sorts to step the voltage down and regulate it.

Most any common universal type power supplies now a days will also work on DC just as well as AC. If they are rated for 100 - 250 VAC input they tend to work just fine on around 100 - 400 VDC.

I have and still do use that method on my wind generators from time to time and so far I have not found a universal input power pack or power supply that would not work on a variable DC input. However most will have a reduced output below a certain input voltage and may not turn on until they are above a certain voltage as well so expect that there will be minimum working voltage at some point where they wont turn on or will automatically shut down as well.
 
Thanks TCM, I have thought about the possibility to having a switching control to pick off volts at differing wind speeds. I did not know about the computer switching power supplies. I do have a several old towers laying in a back room so I'll have to start looking into what can be matched up. I searched and found switching schematics but that is a bit of a stretch for my capabilities.
 
Hi these motors are inderstructable they can be put on big lathe and run at high speed and little or no heat in the windings also they can be easy rewired as they are all exposed so you can join groups of coils together to lower voltage output and increase amps my windmill runs two of these and the stators are electricly cut in half also i wired them in delta, factory they are star my mill max power is 40 amps at 27 volts .
 
Thanks Shawn, I thought I had a possible good generator here but was concerned about the light wire leads. Now I am comfortable moving ahead with the project. I ordered a rectifier today and trying to figure out the optimum route to take for output.

What speed is your mill running to get 27v out? (cut in speed) Do you have any suggestions on a good inverter?
 
My mill is a hawt so can reach 3/4/500 rpm the volts are clampt by the battery bank. but i recomend for slow mills (vawt) that you leave standard first this is about the easiest thing to change later
These motors have been used on waterweels/peltonweels and all forms of mills at 12v, 24v, 48v, grid connected, and stand alone systems, They never burn out. the downside is they cog this can be fixed ! and they only give about 350 watts, more if you flog the heck out of them this will not hurt them but you have to put heaps more power in to get a little back after 300 watts this is why i just put two on .

Before you spend lots of money on inverters etc i recomend that you think hard about vawt they are great to look at but they do not make much power!!
I hate to put you off but i would like you to get some real power after all the time you will put in building a mill.
no power company i know of ever used a vawt .
 
This is a learning project. I live in town so a hawt will likely be out of the question. I'm playing around and if it works well I may expand my play time. There is nothing like a little success to spur an imagination. Here in the north the wind blows the hardest in cold weather (when fronts come through) and that is when a bit of warm water will help cut the utility bill. If it doesn't work out so well I'll give it to a friend that has a hobby farm. We have been pondering the project together so he's into it and has an open breezy place.

I understand what the output will likely be now and I have read up on cogging. I don't get how to solve the cogging in this design though. Is the cogging a serious issue with this motor? It really didn't feel that bad by hand. Would strapping magnets to the outside of the rotor offset to the main magnets help resolve the issue? Would the extra magnets add to the output potential.(likely some, I guess)

I like your idea of changing the windings to delta and combining poles. I haven't looked at it yet to see how deep I'd get into reconfiguring the windings but I will, if nothing else just to figure it out

I'm just trying to figure if there is enough wind to catch to power a 48v w/h element as a dump load or would I be better off keeping the output to 24v? I'll just be setting this a few feet off the ground between the house and the garage for now, that location gets good winter winds albeit turbulent winds. That is why I like the washer structure for the base.

I don't intend to spend much money on the project at least till I know it will be worth it. The rectifier was $20 shipped and the stand was made from free materials so the total is now $29. I have a welder and nearly every tool needed.

Once the machine has a dc voltage and a load I can get some metrics and proceed from them. Today it is all questions though. Thank you
 
Ok the vawt should overcome the cogging most have good low speed power, if after its built it has trouble starting you twist the poles and grind the edges as when you twist them the corners stick up and will rub magnets.
Puting magnets on the outside will not help the factory ceramic magnets are set on a steel band .
Running 24v or 48v mmmm build it first the stator can be changed to suit either, factory it will run up to 48v easy and have a early cut in but will not give many amps
It takes a lot of power to heat water even a great performing mill that is 20 meters high up will struggle to make a big dent at water heating, this said i am going to dump my excess power into the hot water but my new mill will put out 3/4 kw and remember your stator output max 350 watts when there is a gale and much less at any other time.
They are a great stator for first mills .
 
I decided to split the stator into a 1x6c and 2x4c configuration. This will give easier start up in low winds and better power when the wind increases. All this should be in the 12v - 24v range IMHO.

When it is done I'll post some metrics and pix.

My concern is that the 60 series stator may have somewhat light coil wiring for the lower volts. At 12v to 24v I hope to get some warm water from it. I'm ready to solder the reconfiguration so I'll have to see what happens.
 
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