Inverter MPPT Clipping - Enphase IQ7plus vs IQ7A

I was looking to compare two microinverters: IQ7Plus-72-x-US [240V] vs the IQ7A-72-x-US-& [240V] using the Inverter CEC database entries.

I set up a simulation with the same location, same panel, same system design and the IQ7A has a significant "Inverter MPPT clipping" in the Nominal DC energy (kWh) section of the Losses result section while the IQ7Plus doesn't show any losses here.

The IQ7Plus datasheet seems to match the Min/Max MPPT at 27/45V.  The IQ7A datasheet says the Power Point tracking voltage range is 18V-48V but a footnote says the CEC range is 38/43V and the CEC entry does reflect that. 

I presume the 38/43V range is responsible for this result?  Though I don't understand why there would be such a large difference between the CEC range and the non-CEC range reported on the datasheet. 

Hi Walt,

I don't know about those voltage ratings on the Enphase data sheets either. If you want to model the inverter using a different MPPT voltage range than is in SAM's library, you could use the "Inverter Datasheet" model option from the blue drop-down list at the top of the page and enter parameters from the datasheet by hand. This option is more tedious than choosing the inverter from the library, but does allow you to adjust the parameter values.

See this post for instructions on choosing inverter model options: sam.nrel.gov/forum/forum-general/2768 .

Best regards,
Paul.