Generator Equations

[jeraklidis]

Hello I'm new and I want to harness the clouds as my friend. Anyone have an equation for Number of turns, wire gauge, number of coils and magnets for corresponding voltage? Then power rating equations for the voltage, rpms, estimated current and watts produced. Heat losses and any other loss info? Am I missing any? A link would suffice... a written explanation would obviously be better. I program pretty well and if I understand the equations well I'll write them in ASP (web programming language) and use dynamic graphs on-line so paper and pencil will be history ... sort of... I have a site to host it on so if you are tired of answering these types of questions let me be the first to fix the problem with a solution. (For PM 3 phase generators in y or delta... actually I bet I could do it for polyphase....) Hope you can help!

Jake

[wpowokal]

Hmmmmmmmmmmm. hit the banner at top of page that says Otherpower.com, and what do you know a book by our hosts available for you to purchase.

Others books spring to mind like Hugh Piggot.

Oh and one hint, pure mathematics don't have all that much to do with home brew wind turbines.

allan down under

[wooferhound]

The most accurate way to determine the number of turns for your coils.

Go ahead and build your 2 magnet rotors and assemble them without the stator coils. Spin the magnets up to your desired Cut-In speed, around 200 rpm. Then wind test coils and put them in the Air-Gap where the stator will be. Make plenty of electrical measurements of the coil. Wind more test coils and test them. Once you get a test coil that performs like you want it to, then you just duplicate that coil until you have enough to build your generator.

Doing it this way will almost guarantee that your generator will function like you want it to. Mathematics will only get you into the ballpark.

[TheCasualTraveler]

     Correct me if I'm wrong but can't you figure turns with only one test coil?

Suppose you have a test coil of 50 turns putting out 1.5 volts at your desired cut in speed BUT YOU NEED 1.8 volts then you simply take .3 volts / 1.5 volts = 20 % increase in turns so 60 turns will get you to 1.8 volts.

Or 1.5 volts divided by 50 turns = .03 volts per turn so 10 more turns (.03 X 10 = .3) will give you your 1.8 volts.

Just thought this might be easier than random guesses.

[wooferhound]

you are probably correct, but I would still wind another coil using your calculations and then test it for assurance.

[jeraklidis]

Took the RTFM advice and bought the book. Once it arrives and I get a good read I'll post my winding formulas online. Anyone every actually have their own Silicon steel laminations made?

[wpowokal]

Jake once you have read the manual there are some components of design that could be programmed, like internal losses v current (load). This one helps a newb understand internal heating and the real need to limit the output to a safe current. Into this you could plot generated voltage v current  v I squared R losses (heating). Hope that makes sense.

There are so many variable that the constructor can build in ie different magnets, single wire or a number "in hand" when winding coils, air gap affected by neatness of construction, the list goes on.

allan down under