Dear Arsh,
For microinverters, you should model an array with one module per string, and the number of strings in parallel should be equal to the number of inverters.
For detailed instructions on how to model microinverters in SAM, please see "Modeling Microinverters" at the bottom of the Inverter help topic.
You can also find a sample file for a PV system with microinverters on the SAM website:
sam.nrel.gov/samples
Best regards,
Paul.