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The Met Man Newbie Joined: 01/11/2011 Location: IrelandPosts: 3
Posted: 05:37pm 01 Nov 2011
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Hi to you all, great site which I have been looking at for a few days.
I have some questions about the circuit for a Wind Turbine without Batteries.
I am new to Wind Turbines, but have done a 3 day course on building one, and I am seriously considering doing so using Hugh Piggott's Recipe Book.
I live on the South West Coast of Ireland, looking out into the Atlantic, so there is plenty of wind.
My weather data collected over the last 4 years or more shows an average wind speed at 10m above the ground to be about 5 m/s
To keep costs down I have decided to build a 3m turbine running into a Bridge rectifier giving either 24 or 48 volts to add heat to my Geothermal Buffer Tank and/or the Solar one which should reduce the electricity bill!
I do not need batteries, another unnecessary expense in my opinion.
I think I could have two 600W Immersion heaters in the tank with a controller (probably using an Arduino with relays) to decide on level of heating from output from Turbine.
Heating levels as follows:-
Level 1 = 300W (both 600W heaters in Parallel) Low wind speed/Turbine Output
Level 2 = 600W (one 600W heaters only) Medium wind speed/Turbine Output
Level 3 = 1200W (both 600W heaters in Series) Higher wind speed/Turbine Output
Level 4 = 3000W Dump Load for emergencies
I would need capcitors across the DC output from the Bridge rectifier to smooth the output.
My question are:
What value capacitors would do the job?
What resistors should I put across them for safety?
Would 24v be better than 48v? (I know the Amps will be highr for 24v so thicker wire.
How best to sense the output from the turbine?
Does anyone have any experience of doing this?
Thanks for any advice you gurus out there can help me with.
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 02:13am 02 Nov 2011
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Hi Metman
You could use direct AC from the turbine and put one heater on each phase and switch in the extra ones as required, that is if you are using the machine for heating only, if you are charging batteries in the future you could then use a rectifier and switch in the heaters as a dump load. 48 volts would be better to reduce amps and losses in the power cable.
All the best
BobFoolin Around
The Met Man Newbie Joined: 01/11/2011 Location: IrelandPosts: 3
Posted: 07:37am 02 Nov 2011
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Thanks for the reply, VK4AYQ
That sounds good to me.
I have been told I would need capacitors. Any ideas on those?
Francis
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 03:03pm 02 Nov 2011
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No, you do not need capacitors for heaters. As Bob said, you can even run water heaters with straight AC without bothering about rectifiers.
BTW, you have the heating level 1 & 3 above mixed up. Both heaters in parallel would give you max heating and both in series minimum.
Without a battery in the system the Volts would vary widely depending on wind power & turbine RPM so you need to experiment with the heater element wattage.
Klaus
The Met Man Newbie Joined: 01/11/2011 Location: IrelandPosts: 3
Posted: 03:50pm 02 Nov 2011
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Dear Tinker
That is great on the caps!
Ooops! R = V/I ........ Silly Me!
Thanks for that, I can go ahead on that I think
Francis