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Joined: 18/09/2017 Location: United KingdomPosts: 17
Posted: 12:43am 20 Sep 2017
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Hi from the uk and new to the forum. Am building an oil drum savonius wind turbine. I managed to get an LG Smartdrive washing machine, using the hub, stator and rotor. But I need some advice on how to rewire the stator for low rpm, max amps at 12v (batteries). I have inverter, charge controller and plan to make a load dump. Looked at many posts and diagrams on here but all relate to f&p which we dont get in the uk. So any help would be great, also on which leads goto the charge controller etc thanks
flc1 Senior Member
Joined: 20/11/2011 Location: New ZealandPosts: 242
Posted: 01:03am 20 Sep 2017
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Gday Druist that rotor and stator looks similar to an f n p, so I would say you could use the fnp rewire page on this site as a" guide" for how to rewire your stator,, read the WARNINGS on this site about LEATHAL high voltage that the stators can produce . The wires that lead into the stator when it was used on the washing machine.. will be the lead out, to rectifier for dc to your controller, or unrectified ac to your controller.whichever your controller takes.
Im sure there are some people on this site that worked with these stators. GoodluckEdited by flc1 2017-09-21
flc1 Senior Member
Joined: 20/11/2011 Location: New ZealandPosts: 242
Posted: 01:12am 20 Sep 2017
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Have a look at Brucedownunder2's posts on LGs
druist Newbie
Joined: 18/09/2017 Location: United KingdomPosts: 17
Posted: 01:21am 20 Sep 2017
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Thanks Flc1, also, i have a chinese 300w charge controller wondering if this might need something more?
This seems to relate to what i would need for low rpm /vawt when it says "factory wiring" does that mean it doesnt need rewiring?
Edited by druist 2017-09-21
electrondady1 Senior Member
Joined: 12/02/2009 Location: CanadaPosts: 208
Posted: 02:31am 20 Sep 2017
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if you could estimate the swept area of the wind mills that people have used to drive one of those alternators you will get an idea of the size of your vawt needs to be. you will probably need a pulley system to get the the rpm up and multiple savonius units to get the torque.plastic storage container barrels are about the same size as oil barrels and have less mass.
druist Newbie
Joined: 18/09/2017 Location: United KingdomPosts: 17
Posted: 04:14am 20 Sep 2017
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i have some plastic oil drums, though when i tried to do them felt they were not rigid enough, though could give em a go. I am trying to get some weather stats off a friend who has a wifi weather station at my allotment - but figured vawt due to not being allowed anything high up.
Wondered also about for a vawt, instead of putting one on top of the other, would it work horizontal, say 3 half plastic drums on either side?
(((_)))Edited by druist 2017-09-21
DaveP68
Senior Member
Joined: 25/11/2014 Location: New ZealandPosts: 292
Posted: 11:18am 20 Sep 2017
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hi druist
Just to add my 5 cents worth in on electrical characteristics, is the wire copper or aluminium? Also what is the resistance reading between the phase pairs?
Also is it possible to get a volts per RPM reading?
The F&P 36 pole copper stator in star configuration using white rotor cap is about 1.02 VDC per 1 RPM out of the 3 phase rectifier. Example 102 VDC open circuit output at 100 RPM.
DavidThere are realities if you do not accept, will lead to frustration because you will be spending time on wrong assumptions and the results cannot follow! The Dunning Kruger Effect :)
flc1 Senior Member
Joined: 20/11/2011 Location: New ZealandPosts: 242
Posted: 03:30pm 20 Sep 2017
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Druist factory wiring means that is how it left the factory,with that wireing configuration, get a voltage tester, put your stator n rotor on a jig so you can spin it and get some voltage readings vs rpm, I don't have any experience with vawts, but from what I have been told they are not as efficient a a hawt, and I think you work with lower rpm,
So whatever voltage you get for your preffered rpm in your test will be reduced by about 30-40% when its under load, so when you have for example 50 volts at 50 rpm ( thats your open circut voltage)it will reduce to about 35 volts(working voltage under load) for the same rpm when its put into your controller and batterys or whatever you are putting it into, so you have working voltage and open circut voltage. the factory wired stator will have high voltage per rpm, so be careful when you spin it up.
druist Newbie
Joined: 18/09/2017 Location: United KingdomPosts: 17
Posted: 10:12pm 20 Sep 2017
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So it would be better to configure it to a lower voltage 12/24 which would increase the amps too?
flc1 Senior Member
Joined: 20/11/2011 Location: New ZealandPosts: 242
Posted: 09:32am 21 Sep 2017
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yea, find out what your average rpm is and configure it for that
Warpspeed Guru
Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 01:19pm 21 Sep 2017
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That depends on how much wind, how much voltage, and how much current you actually end up getting at your location. And you will not know that until its all installed and running.
Only then you can make some logical decisions about reconfiguring the windings.
If it blows pretty hard most of the time, you will have plenty of rpm, volts, and torque to play with. So you can trade off some of the excess voltage for a higher current.
If its pretty calm to almost no wind most of the time, its going to barely turn and have little torque anyway, so you are going to need to configure for a higher output voltage just to get it working at all.
Those would be the two extremes. But you are not going to know what to expect until its actually running and you have gained a bit of experience with what it can do.Cheers, Tony.
druist Newbie
Joined: 18/09/2017 Location: United KingdomPosts: 17
Posted: 10:34pm 21 Sep 2017
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so the best approach would be to trial the whole setup etc in situ. I can hopefully get pretty accurate wind readings from a wifi weather station nearby.
Would the HAWT still be better even if its only 10ft high?
flc1 Senior Member
Joined: 20/11/2011 Location: New ZealandPosts: 242
Posted: 01:12am 22 Sep 2017
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I think a hawt is the better turbine, but in town you may be better to go with a vawt, some people don't like to see spinning blades nearby, but its up to you
druist Newbie
Joined: 18/09/2017 Location: United KingdomPosts: 17
Posted: 08:49am 22 Sep 2017
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yes thats really my problem. Am going to trial my treadmill motor at my allotment as a hawt, then the stator/rotor as a vawt and see how it goes.
electrondady1 Senior Member
Joined: 12/02/2009 Location: CanadaPosts: 208
Posted: 01:40am 23 Sep 2017
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i live in town so i cant do a hawt but i built 3 bladed drag mills for ten years. i have moved on to a squirrel cage design now and i like them better.they are visually nonthreatening and provide good torque. from a distance you can't even see they are turning .
druist Newbie
Joined: 18/09/2017 Location: United KingdomPosts: 17
Posted: 04:53am 23 Sep 2017
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Do you have a pic of the design? also what you used bearings etc