Permanent Magnet Motor

What would be better for building a wind generator:
1/4 hp 12 vdc 1750 rpm
or
24 vdc, 48 vdc, 90 vdc
or
1/2 hp, 3/4 hp, 1 hp
or
Higher rpm, 3250

If I was to use a PMA for 12.5 mph average wind, what battery voltage would be better?
Someone said, low wind use 12v and medium wind use 24v and so on.

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Permanent Magnet Motor

    You may wish to also ask at the www.otherpower.com forum... They specialize in do it yourself wind projects.

    Selecting a motor--There are so many variables and so many options to choose from.

    Personally, I would probably start with a design (XX diameter wind turbine with direct or gear/belt drive RPM conversion)--then try to find a motor to fit that design.

    Also, 12.5 MPH average wind speed is a VERY WINDY location. Knowing your average and maximum wind speeds for your location will help you pick what sort of wind turbine design will work for your area.

    Low average wind speed needs a large diameter fan mounted on very tall tower (60' or more?). And you can probably get away with a shorted output to keep the turbine from over speeding in higher winds.

    High speed wind gusts need a turbine+tower that will withstand the high wind loading, needs a mechanical braking mechanism, and a furling mechanism.

    Picking a low speed motor is usually better (large turbine diameters spin slower, and gear/belt transmissions add losses and mechanical failure points).

    Knowing what your battery bank voltage will be is helpful too. On a 12 volt bank, turbine will produce enough voltage/current to work in lower wind speeds. A 24 or 48 volt battery bank may mean the same turbine will require 25+ MPH to output any useful energy.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    Re: Permanent Magnet Motor

    You should start out small and work your way up.

    Wind turbines can be dangerous when then get out of control. Make sure your design can handle with wind gusts you get in your area, like a local thunderstorm.

    It is preferred to have two separate methods of speed control as failsafe backup.

    - load dump control
    - mechanical braking
    - turning out of wind
    - blade feathering