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MPPT algorithms, perturb and observe algorithm etc

  1. Mar 16, 2019 at 7:32 PM #1
    Hi,

    I had thought that "hill climbing method" is a general terminology to refer to methods such as perturb and observe and incremental conductance. The same is also said here, "The hill climbing based techniques are so named because of the shape of the power-voltage (P-V) curve. This technique is sub-categorized in three types: Perturb & Observe Algorithm (P&O), Modified Adaptive P & O Method, Incremental Conductance Algorithm (INC)". [Reference #1, page #91: https://www.academia.edu/5691750/Hi..._point_in_Solar_Photovoltaic_Systems-A_Review]

    But at many places they are considered two different methods, for example, "Perturbation and observation (P&O) and hill climbing methods are widely applied in the MPPT controllers due to their simplicity and easy implementation [2-3]. P&O method involves a perturbation in the operating voltage of the PV array, while hill climbing strategy introduces a perturbation in the duty ratio of the power converter [2] and is more attractive duty to the simplified control structure [4][Reference #2, page #804: https://www.researchgate.net/public..._MPPT_methods_for_grid-connected_PV_converter]

    Reference #2, page #805, also lists a flow diagram. Near the end it makes a distinction between perturb and observe algorithm and hill climbing by saying "For P&O MPPT Vref(k)=Vref(k+1)+Vstep*slope" and "For hill climbing MPPT D(k)=Dref(k-1)+Dstep*slope". I understand the hill climbing and how duty cycle is used to change the input voltage of panel to operate it at maximum power point. P&O changes the Vref instead of duty cycle but it can only change the Vref through duty cycle. For both methods, at the end od day, it's the duty cycle which regulates the voltage. So, does the difference only lie in the wording, or is there more to it? Could you please help me with this? Thank you.

    ?temp_hash=ad2bf9ac8d7e572ae3cd4c79a5a67fcf.jpg

    Reference #11: https://drive.google.com/open?id=1JQ4wQkA-M9PwBmRS6xHLhTBLZv3Dk7ou
    Reference #2: https://drive.google.com/open?id=1qthgR8rW572jaaAjmvDFRvnkqtd10mZk
     

    Attached Files:

  2. jcsd
  3. Mar 17, 2019 at 1:51 AM #2
    PS:
    https://www.google.com/search?q="Both+perturb+and+observe%2C+and+incremental+conductance%2C+are+examples+of+"hill+climbing"+methods+that+can+find+the+local+maximum+of+the+power+curve"&oq="Both+perturb+and+observe%2C+and+incremental+conductance%2C+are+examples+of+"hill+climbing"+methods+that+can+find+the+local+maximum+of+the+power+curve"

    It includes results from Wikipedia and US solar institute.
     
  4. Mar 17, 2019 at 7:24 AM #3

    anorlunda

    Staff: Mentor

    Opening a Google drive file from a stranger is a security risk. You may not try any answers until you change that.
     
  5. Mar 17, 2019 at 1:24 PM #4
    Thank you!

    But I have more than 450 posts under my belt! :) Anyway, those Google drive files are PDFs and they are okay to open. Also, even an .exe file from Google drive doesn't open directly, you need to select download first.

    Those Google drive files are the same as those Reference #1 and Reference #2 URLs in my post.

    Finally, I have now attached the same files.

    Best wishes,
    PG
     
  6. Mar 17, 2019 at 2:35 PM #5

    anorlunda

    Staff: Mentor

    Don't take it personally. Each of us has a policy regarding risks on the Internet. Many PF members (me included) object to PDF files. Partially because on many of our platforms you must download the PDF before you can view it. There are also plenty of risks with PDF.

     
  7. Mar 17, 2019 at 2:44 PM #6
    Thank you! No problem. I didn't take it personally. :)

    Actually I included those Google drive PDFs for the same URL documents was that sometimes sources get deleted over time and in such a case a thread might become almost useless to someone who stumble onto it. Also if I attach PDFs here on PF then first you need to download those files fully which I believe is more risky compared to opening a PDF on Google drive.
     
  8. Mar 18, 2019 at 10:08 AM #7
    I would say "hill climbing" is as far as I understand, the overall method, of which perturb and observe is one of.
     
  9. Mar 18, 2019 at 8:30 PM #8
    Thank you.

    I have also looked many places and it looks like perturb and observe is one of hill climbing methods.
     
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