Wind Generator

danielb
danielb Registered Users Posts: 5 ✭
in Wind Power Generation #1
Can somebody on here post schematics of a wind generator? I know the basics of it but I am looking to build one myself since I can not find one to fit my specifications. I am wanting to build a tiny 5volt 10amp (or something along the lines of that) generator for testing purposes.
· Share on Twitter

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: Wind Generator

    Basically you're looking at blades on a permanent magnet alternator, with variations on the them.

    Hugh Piggott's is the best site for DIY wind turbines: http://www.scoraigwind.com/

    I don't think you want to build a 5 Volt generator, as that's rather a "non-standard" Voltage for batteries.

    Basic alternator diagram. The bit in the lower left would be replaced by permanent magnet on the rotor.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,654 admin
    #3
    Re: Wind Generator

    In Marc's (Cariboocoot's) drawing--The "Field Windings+brushes" are frequently replaced with strong permanent magnets (PM Alternator, or PMA). The advantage is PM systems can be more efficient. The downside is you cannot "regulate" the output current electronically--But with wind turbines, you generally want to keep constant loads on the alternator to prevent the blades from "running away" (high rpm) in even moderate winds.

    So, the "simple" PMA is directly attached to the battery bank and a "shunt" (dump/diversion) controller is attached to the battery bank. And the shunt controller "turns on" to dump current to (typically) some sort of resistance heater to get rid of excess charging power (in high winds).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • danielb
    danielb Registered Users Posts: 5 ✭
    #4
    Re: Wind Generator

    Ok, so I understand it as your saying this type of machine is optimal at low rmps? And if so, is there a certain type of generator that does better at high rpms? I am very curious into this field.
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #5
    Re: Wind Generator

    Turbines tend not to be optimal at low RPM's because that equates to low wind speed and in low wind speed there simply isn't much mechanical power to convert to electrical power. Consider that a similar amount of the available wind power is lost in the conversion at any given speed (for the purists: not precisely true) and you see the reasons behind minimum wind speeds for turbine operation.

    Therein lies the big problem: design it to be optimum at low speed ad it's no good at high speed. Design it to be optimum at high speed and it's no good at low speed. Considering that the definitions of "no good" range from "produces no power" to "flies into pieces" and you have the turbine dilemma in a nut shell.

    Beyond that, the windings play an important role in determining output as does the magnetic field that excites them. They both have to 'match' with the mechanical design of the blades in order to get it to work well.

    In the short form: low speed = low wind = low power = not worth the effort.

    Note that this is not the same as the really big, slow-turning commercial turbine units; that is a matter of blade design optimized to provide maximum torque to the mechanical drive. That is then geared up to present a reasonable RPM for the alternator.

    The schematic I posted shows a typical 3-phase alternator of the 'Y' configuration. It could be single phase, or more than 3 phase, or delta configuration, or ...

    Without some set goal in mind of what you're trying to achieve it's impossible to design anything. I suggest you spend a few days reading about the projects on Hugh Piggott's site and see what I mean. It really helps if you have some decent air flow to work with. Too many people try to put up a turbine without that, then wonder why it doesn't work.
    · Share on Twitter
  • danielb
    danielb Registered Users Posts: 5 ✭
    #6
    Re: Wind Generator

    Ok, yea thanks, I will. I am trying to learn but I guess I am trying to rush this. Thank you for the info
    · Share on Twitter
  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #7
    Re: Wind Generator

    Ed Lenz's website is probably the best resource for building a small microturbine. Ed has articles on there covering three-phase basics, along with several small windpower projects he has done, etc.
    http://www.windstuffnow.com/main/

    --
    Chris
    · Share on Twitter

Categories