Consider replacing inverter methods in PVSystem with a single method with a kwarg

#886 moved inverter-related functions from pvsystem.py to inverter.py. Methods PVSystem.snlinverter and PVsystem.adrinverter currently wrap inverter.sandia and inverter.adr, respectively, which previously were pvsystem.snlinverter and pvsystem.adrinverter.

Perhaps renaming the functions creates potential for confusion.

It may be an improved API to replace PVSystem.snlinverter, PVSystem.adrinverter and PVSystem.pvwatts_ac with a single method PVSystem.dc_to_ac or similar, with a kwarg model='sandia' for example.

Opening for discussion.

[cwhanse]

ModelChain.get_ac wouldn’t have that issue, I think, since it can inspect ModelChain.results.dc and get what’s needed.

For PVSystem.get_ac(pdc, vdc=None) is similar to what I see done in e.g. scipy.optimize.minimize where many methods are wrapped, and some kwargs are needed for some but not all methods.

[wholmgren]

Method generally looks good to me. A few suggestions:

• model is required, so it should be an arg or a kwarg with a non-None default value.
• I think the _validate_per_array calls belong outside the if block.
• replace the if model not in ['sandia', 'pvwatts'] with an else block that raises the same ValueError

I think it’s easier on the user to build the multi-array inverter model selection into this method.

I’m ok with that. Would you apply the same logic to the modelchain layer? That would be my preference.

ModelChain.get_ac presents a different problem.

We don’t necessarily need to do that at the same time. Those ModelChain methods should be cleaned up but I’m less concerned about them. I don’t think anyone uses them directly and I wouldn’t have concerns about changing them without deprecation.

As for actual implementation, one way might be to set the attribute equal to a partial(self.system.get_ac, model=ac_model).