Villalva Algorithm Pull Request

[JFrederico2022]

• Closes #xxxx
• I am familiar with the contributing guidelines
• I attest that all AI-generated material has been vetted for accuracy and is in compliance with the pvlib license
• Tests added
• Updates entries in docs/sphinx/source/reference for API changes.
• Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels (including remote-data) and Milestone are assigned to the Pull Request and linked Issue.

[github-actions]

Hey @JFrederico2022! 🎉

Thanks for opening your first pull request! We appreciate your
contribution. Please ensure you have reviewed and understood the
contributing guidelines.

If AI is used for any portion of this PR, you must vet the content
for technical accuracy.

Finally, be sure the PR description includes the PR
checklist,
and complete the items you are able to.

[cwhanse]

@JFrederico2022 pvlib should get only the functions, not the notebook. It has been a while since we discussed that: #2754 (comment) "In pvlib, a calcparams_villalva function would go into pvlib.pvsystem. Code for fitting would go into pvlib.ivtools.sdm in a new module villalva.py"

If you want, you can convert the notebook to a python script and add to the Example Gallery. Just start the script name with "plot_" and use docstrings where you want text to appear.

[JFrederico2022]

Hello, @cwhanse

I updated the docs. Please, let me know if they are all right.

Best regards,
João Frederico

[ramaroesilva]

Hi @JFrederico2022, great initiative!

In my opinion, I think it would be nice for your PR to have a corresponding issue which includes a description of what you are adding to pvlib (e.g., what do you see is missing that a PR would add and include sources). That way reviewers and curious people can have a quick outlook of what's happening.

[RDaxini]

Hi @JFrederico2022, great initiative!

In my opinion, I think it would be nice for your PR to have a corresponding issue which includes a description of what you are adding to pvlib (e.g., what do you see is missing that a PR would add and include sources). That way reviewers and curious people can have a quick outlook of what's happening.

The issue exists (#2754) but, @JFrederico2022, please tag this in the PR template

[echedey-ls]

Remember to list the new functions in https://github.com/pvlib/pvlib-python/blob/main/docs/sphinx/source/reference/pv_modeling/sdm.rst?plain=1

[RDaxini]

I have suggested a few basic docstring revisions. You can implement changes recommended by reviewers either by committing them individually or, under the Files changed tab, adding the suggestions to a batch and committing them all at once.

Happy to look more in depth at the core implementation in the coming days

[markcampanelli]

@JFrederico2022 For the validation plot below, my understanding is that the Villalva model was fit to each temperature and irradiance condition separately. However, as I understand it, the original SDM paper describes using the Isc and Voc temperature coefficients to compute I0 away from STC (in particular, avoiding the need for a bang gap parameter value). I am curious what the validation looks like using that extrapolation of the fit at STC, rather than separate "local" fits at different operating conditions. For PVfit, I have used IEC 61853-1 matrix measurements to assess how well a fit using STC conditions extrapolates to a wider set of conditions, and I have attached an example of that. (IIRC, this was a rather good fit, but other fits do not extrapolate so well away from STC.)

More pertinent to this PR, is the SDM using the Isc and Voc temperature coefficients implemented here?