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Rshunt value used to compute reverse saturation current may be inaccurate

Open markcampanelli opened this issue 4 years ago • 4 comments

Rshunt can be a bad approximation to the shunt resistance at reference irradiance, as described in

https://github.com/pvlib/pvlib-python/issues/1094

In particular, this affects the fit of the reverse saturation current at reference conditions

https://github.com/frivollier/pvsyst_tools/blob/master/pvsyst/module.py#L275-L278

markcampanelli avatar Nov 22 '20 16:11 markcampanelli

added separate parameter with computation of shunt resistance at 1000 w.m2 ('RShunt_1000') and replaced the R_sh_ref by this new computed value rather than RShunt from the PAN file. https://github.com/frivollier/pvsyst_tools/commit/c755d73d7035b0cd05ec9a1a3fa62b5763a8ccd9

New notebook: https://deepnote.com/project/e3c9fe22-c006-42ba-af37-1d51ed2de5b0

frivollier avatar Nov 28 '20 22:11 frivollier

I will add more clarity to what each shunt resistance parameter mean and will double-check which to use with pvlib.

frivollier avatar Nov 29 '20 16:11 frivollier

@frivollier There appears to still be a small discrepancy between pvlib's implementation and the one here, see https://github.com/pvlib/pvlib-python/blob/master/pvlib/pvsystem.py#L2264.

If you concur, then I'd be happy to make a PR to address. Please let me know what you think.

markcampanelli avatar Mar 24 '22 21:03 markcampanelli

@frivollier I raised the idea of moving the code here over to pvlib-python, and the folks there seem amenable. Would you be ok with this? I'd certainly like to somehow preserve credit to you and this repo in the new code.

markcampanelli avatar Apr 05 '22 13:04 markcampanelli