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VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539

Posted: 07:21am 12 Aug 2010

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Hi All

I have a Chinese 500 watt wind turbine I have been experimenting with, and as we finally had some wind I was able to try out some ideas I have been toying with for several months.

The mill itself I rebuilt from a basket case and the regulator was sent to the parts bin, the mill is working quite well now 20 amps at 30 volts at 8 ms and up to 50 amps on higher speeds, however it starts at 2 ms and spins a lot without doing any useful work, I tried the cap booster circuit with little success, so have gone a different way.

I have now fitted it up with a dual voltage recovery system, the 24 volt rectifiers are left in place, and the cap rectifiers have been disconnected to the main batteries 24 volt and connected to my 12 volt lighting and radio batteries, there is a currant limiter in series limiting the current to 10 amps to trickle the 12 volt batteries this picks up the power generated at low wind speed 2.5 ms and up to the 24 volt cut in at 6.5 ms.

While the mill is turning slowly it makes 12 volts AC 14 volts dc it starts to charge the 12 volt battery up to it comes to the current limiter then the AC volts goes up to 22 volt AC and it starts to charge the main batteries.

It is working well and recovers those low end watts normally lost, and surprisingly it lowers the cut in speed for the 24 volt system and makes no difference to the 24 volt output, I think it is energizing the fields due to current in the windings, not sure but it does happen and is noticeable.

I also tried a 300 watt GTI direct on the mill and that works as well and it trickles a few watts into the system as well, it cuts in a 14 volts dc and works all the way up to 27 volts battery charging, another success, if the charge voltage goes above 30 volts it cuts of as it has a high voltage cut out.

Any ideas for improvement would be greatly appreciated.

All the best

Bob

Foolin Around

Downwind

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Joined: 09/09/2009
Location: Australia
Posts: 2333

Posted: 07:37am 12 Aug 2010

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What is your current limiter. A simple resistor??

Pete.

Sometimes it just works

VK4AYQ
Guru

Joined: 02/12/2009
Location: Australia
Posts: 2539

Posted: 09:42am 12 Aug 2010

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Hi Pete

The limiter is a Fet with a sensor reading the current and controlling the mark space ratio of the driver. It is based on a HHO controller that I had set up on a HHO cell I was playing with.

All the best

Bob

Foolin Around

VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539

Posted: 01:44pm 12 Aug 2010

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Hi All

This is a wind speed ms chart during testing of the dual voltage setup.

All the best

Bob

Foolin Around

VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539

Posted: 11:24am 13 Aug 2010

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Hi All

Back again for the second day of windy test weather the wind has been light and usable to test the GTI.

It has been connected for the last 24 hours and has been ticking away most of the time, I found that it needed a capacitor across the input to keep it from loosing synchronization with the mains, a couple of 500 uf in parallel to give 1000uf sorted out the problem of it dropping of sync between syncable events, it would hold sync down to 10 volts AC from the mill. At 15 / 16 volts AC it was doing rated output of 300 watts.

Wind Chart for the 24 Hours

It has contributed 1500 watts + for the 24 hours, not a lot but every little bit helps.
The wind has been variable for the 24 hour so give a fair idea of the yield.

All the best

Bob

Foolin Around

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