Some questions about wind

[terramir]

Hi I have been browsing about wind power and I got some question.

A. If you make a certain amount of windings per coil will this give you a fixed or variable voltage? depending on the wind speed or does the current vary with wind speed?

B. I know that depending on the gauge of the wire the current capacity varies.

C. I looked at that experimenter kit at windstuff now, however the question is if I build a simular design do I have to use wedge shaped magnets or will any kind do?

D. if the magnets I see have the magnetic poles on the flat surfaces would that be ok?

E. As for the controller I need for wind power, on those silly days where the average wind of 7.5mph is far exceeded will i need a dump load or can it just disconnect?

F. just curious questions I could use some formulas on nominal voltage vs windings, And with a 3 phase motor to the currents or the voltages add up once you rectify?

terramir

[wdyasq]

On the upper section of your screen there is a link to 'otherpower.com' If you go there many of your questions, plus answers to many more you have not thought to ask, might be answered.

Ron

[DanB]

Hi Terramir - yes, Ron has it about right, you should read over our page at otherpower.com - I would suggest you get 'Wind Power Workshop' by Hugh Piggott and perhaps get a copy of his plans.  Wind Power Workshop is fun to read - it will answer all these questions and many that you'll be asking next I suppose.

Some short answers...

A. If you make a certain amount of windings per coil will this give you a fixed or variable voltage? depending on the wind speed or does the current vary with wind speed?

Voltage is related directly to rpm, and directly to the number of turns in a phase.  (double either one and voltage will double)

B. I know that depending on the gauge of the wire the current capacity varies.

Yes-  thinner wire has more resistance and can handle less current, but you can fit more in and have higher voltage.  For any given wind turbine design you need to get the wire gage and the number of turns just about right or it likely won't work.

C. I looked at that experimenter kit at windstuff now, however the question is if I build a simular design do I have to use wedge shaped magnets or will any kind do?

The size/shape of the magnets is pretty important.  There are surely other shapes that would work well with the same stator - so long as the size/spacing is reasonable.  So - you don't have to use wedge shaped magnets but 'any kind' won't do.

D. if the magnets I see have the magnetic poles on the flat surfaces would that be ok?

Yes - that's normally how NdFeB magnets are and that's what everyone is using.

E. As for the controller I need for wind power, on those silly days where the average wind of 7.5mph is far exceeded will i need a dump load or can it just disconnect?

It's not usually good practice to disconnect a wind turbine ever.  If you're very attentive (you use your brain and a switch as the controller) you can shut down the machine by braking it to save your batteries.  That's not very practical for the long term though.

F. just curious questions I could use some formulas on nominal voltage vs windings, And with a 3 phase motor to the currents or the voltages add up once you rectify?

I'm afraid I don't understand the question.... ;-)

[Devo]

I'll take a stab at the last one for you , may not be what your asking for though

F. "just curious questions I could use some formulas on nominal voltage vs windings"

the voltage per turn in the winding directly relates to the amount of magnets per rotor & the strength of the magnets so if you have 10 turns in your coil & it gives you .5 volts in your paticular set up say 12 magnets in a dual rotor , if you switch the amount of magnets on the rotor, the strength of them or the distance of the magnets to the coil or the distance between the magnets the voltage will vary. I think it is because of these variables that a formula is not readily available (that I know of)

Many here have built machines & can give you guidelines, for example I have built a dual rotor machine with the magnets spaced on a 12 inch steel rotor, they are 1/2" apart using grade 42 neo's 1" X 2" X .5" therefore I can tell you the voltage of a coil with 10 wraps at a certain rpm under those circumstances.

" And with a 3 phase motor to the currents or the voltages add up once you rectify?"

Assuming you have converted the 3 phase motor into a PM generator & are using the stock windings if you rectify it in star the voltage of one open phase of AC should multiply by 1.73 then again by 1.4 (I believe) & then drop by 1.4 for the diode drop. If you where to connect in Delta it would raise the voltage of 1 phase X 1.4 & the diode drop of 1.4 but the current would multiply by 1.73(I Think).

Sometimes there are better ways to wire a stock winding buy splitting the coils & stuff so a good read under a search of induction motor & Zubbly is highly recomended.

Getting into windpower is a bit of reading but the end result is more than worth it, keep at it & soon you'll be posting a picture of your first power plant.

Have Fun

Devin