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BarkyJ
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Posted: 29 April 2018 at 12:32pm | IP Logged Quote BarkyJ







No stickers on these ones, but clearly marked CU.


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DaveP68
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Posted: 29 April 2018 at 12:48pm | IP Logged Quote DaveP68

Yep they are both 36 pole copper stators.

A word of caution relating to rewiring these or any other stators. Once it's been rewired to the chosen setup, it is not always possible to rewire to a different setup! It can be one way trip if you get what I mean.

Feel free to as any questions regarding rewiring them.

P.S. edit, make sure you now have 2x black rotor caps to go with these 36 pole copper stators to gain the maximum power output potential.

Edited by DaveP68 on 29 April 2018 at 12:51pm
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BarkyJ
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Posted: 29 April 2018 at 4:24pm | IP Logged Quote BarkyJ

Thanks Dave,

Yeah at the moment I only have 1 black cap, but hunting for another. At least though I do have a white cap which matches, but isnt the higher power version obviously.

So black caps only came with 36 pole AL stators? and the 36 pole CU stators all had the white caps?
Then the older 42 pole stators had a mixture of white and grey caps it seems.

Why do you say its not always possible to rewire a different setup? Understand its cutting windings etc, so joining them up isnt exactly ideal, but It shouldnt be a one way path surely...

Once I find another black cap, I guess its a decision I then need to make, on how I proceed with the next part.

As has been mentioned previously, 12V/24V systems dont seem to be recommended..., so I guess we are now talking 48V as being the standard? Sadly does mean 4 batteries just to get up to that voltage, but I guess thats just part of it.

What I was ideally wanting to do, as mentioned already, was to get something at least contributing to hot water. If I had wind powering the water cyclinder which is thermostat controlled, and then maybe 5am it cuts back to mains to ensure there is hot water for the morning. Switch the wind to bypass to a heater element or something when thermostat is to temp, or its selected on mains.

Generating mains voltage I guess isn't ideal, but does it make sense if using it for something like water heating? Or is it still best to go into batteries, and then use a DC element, or invert it back into mains? I am not sure what is best practice here. I have seen on Aliexpress 24/36/48V DC elements, ranging from around 900W to 2000W or something. Next question would be plumbing 2 elements into a single cyclinder, or having a secondary cyclinder in parallel or something like that. All details to figure out I guess.

At this stage I just want to set up a trial. This property isn't ideal for a large windmill, so if I can get some sort of hobby system up and running to learn from, that would be a good start. Have to get the generator built, then figure out the windmill, then figure out what comes next, so still a lot of steps I need to go through I know.
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flc1
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Posted: 29 April 2018 at 6:53pm | IP Logged Quote flc1

what Dave means about rewireing a stator is that it gets difficult and messy when you try to rewire a stator too many times,

might be an idea to practice on your alu stators first,
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DaveP68
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Posted: 30 April 2018 at 10:30am | IP Logged Quote DaveP68

Yes the CU stators only have the white caps and the AL stators only have the black caps so you need to find another machine with an AL stator to get a 2nd black cap.

Fred is the first person I know of to make use of the CU stators and black caps to improved the output power on both of his wind turbine builds.
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BarkyJ
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Posted: 30 April 2018 at 11:01am | IP Logged Quote BarkyJ

Neat, thanks guys.

In terms of the electronics to charge batteries, and the coil arrangements, I have a few questions.

So if I pick a basic wiring arrangement of the stator, say a 4x3C, for a 24V system. In the table on the rewiring page it lists star and delta configurations and RPM's. So in Star, you start getting 24V at about 81RPM with the 36 pole with black cap, and in delta you get it at about 140RPM, is that me reading the table right?
At what point does it start to drop off, do you know? Like in a high wind, I imagine the star configuration would not fare as well... Which I guess is where you start getting into the staggered setups and dual stators etc, to make use of all sorts of wind, right? or is it more about making better use of high wind to make more power, rather than the power dropping off in high wind?

When wired in 4x3C for 24V, what is the actual voltage range you get out, approximately? or is it always about 24V, but the amperage just increases with a higher wind? What about unloaded, does the voltage just keep increasing?

If you rectify that into DC, and chuck that directly into a battery, then I imagine you getting into battery boiling territory pretty quick, as you have no voltage/charge control, and no way to shut things down when the battery is full.

So if you then put a relay in line, and a monitor on the battery to switch the load onto a dummy load instead of the battery when its full, then that solves the over charging issue, but this still has no voltage control for what voltage you are actually charging at...

So for small setups, what do people use?
I have seen a number of builds with what look like expensive controllers etc. But did you start with something cheap and progress to those? Im just trying to find a reference point to start with, and whether or not I buy something or make something to suit - its just the starting point I need.

Having never played with windmills, and therefore I dont know when you wire one up in say 4x3C 24V, what is the voltage range you get out after rectifying it. If I know that, then I could build something to regulate that down into battery charging territory, and have a cut off to dummy load, and battery monitoring etc. But I just dont know what ranges to expect.

Also is there an approximate wattage output you get from a single 36 pole with black cap, in an average installation? I imagine it comes down to a lot of factors, and i haven't even started looking up the prop or size of that, or even what torque is required to turn one of these things... but in terms of sizing a charging controller, what should I be aiming for?

I am very much use to dealing with stable voltage input sources, not variable and intermittent as you get from these windmills, so please forgive the ignorance.

Without getting too deep immediately, I think I want to do a test setup with 24V, and then move to 48V longer term.

Sorry for the long post, I hope someone can give me a nudge in the right direction.

Edited by BarkyJ on 30 April 2018 at 11:03am
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flc1
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Posted: 02 May 2018 at 5:22pm | IP Logged Quote flc1

Gday Barky,
seems like you are on your way to working things out, open circut voltage (no load) can be up in the 200-1000v, depending on you stator cut....very leathal. if you have large capacity batterys they will handle whatever your turbine throws at it,
but I would suggest you spend a little money and get a 20-30 amp charge controller with dumpload for your batterys at the very least,save you the hassel of trying to build somthing ,,,and cooking your batterys
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BarkyJ
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Posted: 02 May 2018 at 7:57pm | IP Logged Quote BarkyJ

Thanks.

I have been thinking.

To start with, I wonder if I should just rectify the windmill power, aiming at 24V, and put that directly into a dual hot water cylinder AC/DC element, which will serve as a dump load, as well as testing out the windmill. This then means I don't need batteries to start with, nor do I need a controller for the batteries.

I am thinking of building a different sort of controller which will PWM the element (load) at a fast rate, to regulate the average load seen on the windmill. So say I have a 900W 24V load, being the DC side of the element into my hot water cylinder. If the windmill is just ticking over, then I can put say 10% duty on the PWM, and put that into the cylinder. If its flying around, then I can put 100% duty into the cylinder. I can monitor the voltage coming in from the windmill and adjust the output load to suit. This will then allow me to map the windmill, see what its capable of, and then sort the battery side of things for alternate use of the power, other than for water heating.

I found a seller on Aliexpress who makes DC elements for hot water cylinders, and they can make me a dual AC/DC version. Have say 2000-3000W or so on the AC side, and then a separate 900W 24V ring also. Both could be run at the same time, but I would likely have my controller which is handing the PWM above, to switch in and out the mains depending on water temperate and time of the day, and incoming power etc.

The aim being, all day/night the cylinder is being charged with the windmill. If it gets to 5am and the cylinder has not had much charging, then enable the AC, and warm it up before morning showers are needed, then shut it off about 7am or something, and go back to just windmill powered.

Hot water is the main thing that eats our power bill. We have a mains pressure electric cylinder, and we have a tenant in a self contained sleepout off the side of our house which also uses our cylinder for hot water, so 3 adults, 2 kids. If I can supplement the heating of the cylinder, without having to go with batteries etc just yet, then I think there would be quite a cost saving on power just for that.

It ends up being quite simple too.

Then once I figure out the capability of the windmill, and how much power I can realistically get out of it during an average 24h, then I can plan the next step. Powering the house off batteries just wont happen, but supplementing hot water power with wind I think would be the ticket.

Just in discussion with the AC/DC element guy at the moment, to see if I can get a sample made, and see how much it will cost. I found one on Trademe, similar thing, but the DC side was 7ohms, so it needs like 170V or something to get full 600W, and at 24V it was only about 80W which is a bit useless. Whereas the one I am looking at would be 0.64ohms, so would dump like 37.5A at 24V at full PWM, or I could drop that right back depending on wind speed.

Would love to hear peoples thoughts - as you guys know alot more than me about windmills :)

Thanks
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BarkyJ
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Posted: 03 May 2018 at 1:04pm | IP Logged Quote BarkyJ

So stoked. Got myself a big as storm water pipe to make my propellers out of. Its about 630mm diameter with 18mm thick walls and 1.5m long. FREE :)
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flc1
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Posted: 03 May 2018 at 6:40pm | IP Logged Quote flc1

Cool, sounds like your sorted, have a yarn with fillm about some blades, they will give you so much more power .
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BarkyJ
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Posted: 03 May 2018 at 8:17pm | IP Logged Quote BarkyJ

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BarkyJ
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Posted: 03 May 2018 at 8:30pm | IP Logged Quote BarkyJ

Yes I have seen his stuff
http://www.ozwindengineering.com/Products.php
Really good, and something I will aim to use in time, but now I am trying to prove a concept on the cheap, but trying to do it as right at possible for a first timer, at the same time.

Want to give this a go, and see what happens, and if it works then I can look at upgrading/changing as time goes on. I just want to prove the concept first without spending a lot of coin (which I don't have spare at the moment).

I have a 3 phase rectifyer the same as is on that page, already on its way. The slip rings are neat that are on that page, and something I will look at if required down the track, and yes the blades are ideal obviously.

Edited by BarkyJ on 03 May 2018 at 8:32pm
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