MPPT for wind turbine

Discussion in 'The Projects Forum' started by Burnit0017, Jan 4, 2012.

  1. Burnit0017

    Thread Starter Member

    Feb 15, 2010
    101
    3
    http://www.youtube.com/watch?v=0TE38SOdf64&feature=player_embedded

    This is a video that demonstrates the benefits of using a MPPT circuit with the system.

    Is there a reason why the P MOSFET trigger signal can not be a fixed frequency? I do not understand the need to vary the trigger frequency based on the alternator’s RPM?

    http://www.youtube.com/watch?v=0TE38SOdf64&feature=player_embedded

    After watching the video I was inspired to try to build my own. The attached photo is a basic concept of the intended circuit. I found a article that helps calculate the values for the components. But I do not understand why the trigger frequency is related to PMA RPM? Thanks for any help received.
     
  2. crutschow

    Expert

    Mar 14, 2008
    12,973
    3,219
    MPPT matches the alternator impedance to the apparent load (charger) impedance for maximum power transfer from the turbine generator to the batteries. The equivalent impedance presented by the charger is determined by the trigger frequency of the switching MOSFET and the current. As the current changes with wind speed, the trigger frequency has to vary to keep the equivalent load impedance at the desired value.

    If you Google MPPT you will find much information on this.
     
  3. Burnit0017

    Thread Starter Member

    Feb 15, 2010
    101
    3
    Hi, thank you for the information. I have decided to start with a basic variable input DC to DC buck converter. I was able to get parts of the shown circuit working, namely the nand gate oscillator and the voltage multiplier. The problem I am now facing is the output capacitor is not oscillating. It has a 1.5 volt ripple at 20 volts. I am currently searching for alternatives and comments are welcome.
     
  4. Burnit0017

    Thread Starter Member

    Feb 15, 2010
    101
    3
    Hi, additional information about buck converter circuit:
    I am starting with a very basic circuit, 5 amp max.
    Input voltage to the buck converter from the PMA is questionable.
    Spinning the PMA manually the open circuit voltage can be as high as 60 Vdc.
    The MOSFET I am starting with is a IRF510, mainly because it is available.
    Comments are welcome.
     
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