convert 3-phase AC motor to PMA

I have read somewhere you can convert a 3-phase motor to produce power from a wind turbine. I think there are no changes to the motor needed. If I remember right you can just run the three power leads from the motor to a rectifier that will convert the power to DC. If this is not correct can someone give me a link or explain how i can do this.

thank you

Comments

  • CariboocootCariboocoot Posts: 17,615Banned
    Re: convert 3-phase AC motor to PMA

    Nope: no "source" magnetic field in a standard, 3-phase AC induction motor. You'd have to gut it and replace the rotor (armature) windings with permanent magnets to make a giant PMA.

    Otherpower http://www.otherpower.com/ has a lot of info on DIY wind generators, including plans & real-world stories of success/failure.

    Also see Hugh Piggott's web site: http://www.scoraigwind.com/

    There's no simple, easy way to do it and most of the time you haven't really got enough wind to make any significant power, no matter what your blowing hair might be telling you! :p
  • System2System2 Posts: 6,290 admin
    Re: convert 3-phase AC motor to PMA

    Thank you for the info.
  • peterakopeterako Posts: 144Solar Expert ✭✭✭✭✭
    Re: convert 3-phase AC motor to PMA

    If you see the links before you will see that there is no metal inside the coils.
    A 3 phase motor is using metal in the coils.
    The difference is with out metal you drop a little eff. but it is starting and running better.
    The magn. field is braking or stepping like a stepping motor ( you are making a big stepping motor).
    And this also makes it more difficult to start.
    second these type of motors are running 3000 - 3600 rpm a home build PMA wil be 300 to 400 RPM.
    running 2 meter blades on 3000 Rpm is asking for major problems.:blush:
    Greetings from Greece
  • LucManLucMan Posts: 210Solar Expert ✭✭✭
    Re: convert 3-phase AC motor to PMA
    Honsolo wrote: »
    I have read somewhere you can convert a 3-phase motor to produce power from a wind turbine. I think there are no changes to the motor needed. If I remember right you can just run the three power leads from the motor to a rectifier that will convert the power to DC. If this is not correct can someone give me a link or explain how i can do this.

    thank you

    It can be done with single and 3 phase motors with capacitors wired across the phases. Not sure if you could use wind to spin the motors fast enough.
    I think this is what you're looking for.
    http://www.qsl.net/ns8o/Induction_Generator.html
  • phred01phred01 Posts: 35Solar Expert
    Re: convert 3-phase AC motor to PMA
    Honsolo wrote: »
    explain how i can do this.

    thank you

    yes 3 phz can it relies residual magnetism to work downside is extracting too much power can cause the rotor's magnetic field to collapse. To make work reliably need to fit the rotor with a permanent magnets.
  • CariboocootCariboocoot Posts: 17,615Banned
    Re: convert 3-phase AC motor to PMA
    phred01 wrote: »
    To make work reliably need to fit the rotor with a permanent magnets.

    Hmm. That sounds familiar.:roll:
  • toppertopper Posts: 113Solar Expert ✭✭✭✭
    Re: convert 3-phase AC motor to PMA

    We have played a bit in the shop with 3 phase motors. They "can" work as a generator but yes there is a lot of behind the scenes labor involved.
    We tried inducing a magnetic field in the rotor but under any load on the output the magnetic field collapses and no power is generated.
    Then we played with rewinding the stator(painful job the pros can keep)and machined in some magnets to the rotor. It kind of worked given our crude methods.
    In the practical world, it would not have generated anything due to heavy cogging. We did manage to generate usable power @ 350rpm though..
    Magnets should also be secured to the rotor using a better bonding agent. JB weld does not hold at high revs.
    Time well wasted! Fun and challenging project that blew up. Success and giggles...
    And for everything else there's mastercard and NAWS(who happens to sell wind generators built by professionals).
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