Rewinding alternator for wind turbine

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Bricolo07
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Rewinding alternator for wind turbine




by Bricolo07 » 09/08/16, 21:15

Hello,
For those who do not know me, I come here every year during the holidays to advance my wind project.
I currently have a wind turbine (1.9m in diameter), blade and generator axial flow homemade, photo on my previous post. I'm here to improve the generator part, and I'm looking for advice or testimonials from people who have rewound a car alternator.
currently my problem is that with the axial flow has a high starting torque which prevents the blades from starting and that the tension produced is not regulated. I think that with an alternator whose excitation passes by a relay 5v on micro engine can be ne solution to avoid a conso empty and to have an output regulation.
Thank you in advance for your feedback
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Bricolo07
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Re: Alternator rewind for Wind turbine




by Bricolo07 » 08/10/16, 21:21

hello everyone, I have rewound my alternator but going from 8 turns in 1 mm to 20 turns in 0.85mm is not enough. I had another idea, it is possible to wind in single phase, because I find that when the three phases are superimposed in offset we lose space, I think I can put more copper if each notch is filled in the same way . I know that the power will drop and only one phase will heat more, but I'm looking to produce 13.4v as soon as possible.
I don't know if it's bullshit but I can't find any info on it on the internet.
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izentrop
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Re: Alternator rewind for Wind turbine




by izentrop » 09/10/16, 00:20

Hello,
Bricolo07 wrote:currently my problem is that with the axial flow has a high starting torque which prevents the blades from launching
I did not see the photos, but with an axial flow generator like this: http://www.heliciel.com/Library/generat ... 0axial.pdf .
If the coils are air, without ferrous core, they offer no resistance if they are not loaded. So when empty it must rotate freely.
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chatelot16
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Re: Alternator rewind for Wind turbine




by chatelot16 » 09/10/16, 11:40

increasing the number of turns allows you to do the same tension at a lower speed, but do not forget that power = torque x speed

working at lower speed does not change the maximum torque: therefore the useful power is divided in the ratio of speed reduction

and worse the excitation power remains constant ... therefore below a certain speed the excitation power becomes greater than the power produced

an average alternator like 30A 12V is 360W ... it's not huge, and by reducing the speed it becomes shabby

a car alternator is not optimized for performance at low speed ... it is optimized to exploit a certain speed range, but it is at high speed that it is best: the regulator reduces the excitation for just make the right voltage, it is far from saturation and has a less bad performance ... when the engine idles the excitation increases to saturate and heat ... but on a car it has no important because the engine has more than enough available power

with a wind turbine you should never use the regulator of the alternator, because the slower the wind turbine the more it increases the excitation until it stalls: it is better a fixed excitation current than a regulator which does the opposite what's needed

adjusting the excitation current allows you to choose the speed when it charges a lead-acid battery ... when you decrease the excitation it lets the wind turbine turn faster ... when you increase it it turns it more slowly: so we can experimentally find out how fast it produces the most power
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izentrop
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Re: Alternator rewind for Wind turbine




by izentrop » 09/10/16, 19:56

The car alternator has no interest for the reasons you invoke and also because of the power consumed by the excitation which reduces the efficiency.
What works best is the permanent magnet multi-pole axial flow, the proof http://www.sepen.fr/index.php?option=co ... &Itemid=27
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Bricolo07
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Re: Alternator rewind for Wind turbine




by Bricolo07 » 29/12/16, 20:26

Hello,
and thank you for these last two messages that I had not seen.
I'm always looking for the best possible generator for my wind turbine which has also evolved.
I agree with you, the axial flow is the best but the regulation is not done and I have not planned to buy it.
If I remove the regulator from the alternator, at how many v and A do I energize my rotor?
For me the starting torque is not a concern because I put a very small 12v motor (video recorder) which produces 12v at 150 rpm from the wind turbine, on these terminals I connect a 12v relay which controls the excitation of the alternator, which means that at less than 150 rpm, there is no resistance.
good idea?
I was doing my tests on an old alternator, I managed to recover a more recent one which I find at a lower resistance but there are new pins (DF) and I do not know what to do with it. I will also create a new topic for all the questions in my head
Thank you
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balandar
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Re: Alternator rewind for Wind turbine




by balandar » 27/11/17, 00:36

Hello
there are wind turbines all made on the market not too expensive and which have a more serious performance than a DIY car alternator whose stator will not hold anyway over time
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Bricolo07
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Re: Alternator rewind for Wind turbine




by Bricolo07 » 09/10/21, 09:45

Hello,
an example of a successful model?
please
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