How do you use SAM with Microinverters (APSystems)

The SAM setup seems to only allow string inverters... As most installs are shifting to microinverters and APSystems is the manufacturer of choice for these products I'd like to know how to use them here.

Is there a pre-made datafile for the YC-500A and YC-500i at 240v, YC-1000 3 phase in 208v, 480v with the correct settings and inputs?

Hello,

You can use SAM's detailed photovoltaic to model PV systems with either string inverters or microinverters. For a system with microinverters, you'll set the number of modules per string to 1, and the number of inverters equal to the number of strings in parallel. Those inputs are on the System Design input page.

You'll also need to set the module mismatch loss on the Losses input page to zero -- you can click the Microinverters button under "Default DC Losses" to set loss values to their default values for a system with microinverters.

The inverters you provide datasheets for are available in the CEC inverter library for the Inverter CEC Database model option on the Inverters page.

Best regards,
Paul.

Dear "Paul",

It´s ok to use SAM to string inverters with multiple MPPTs.
But when shifting to Microinverters, I really haven´t got it yet.

My first question is if you plan to add APSystems microinverters, that´s way more used than hoymiles ones and also met CEC requirements. 

Considerations:
a) In one post of mine, you explained an error I was questioning: "That error indicates that the value of Number of MPPT inputs on the Inverter page is different than the number of subarrays enabled on the System Design page. "

b)You´ve also recommended to set the number of MPPT inputs to one on the inverter´s page.

Questions:

1) Is this setting (b) also applicable for microinverters that can have 4 modules connected? Or in this case the number of MPPT inputs should be set to "4" ?
2) You said: "you'll set the number of modules per string to 1, and the number of inverters equal to the number of strings in parallel." This setting will lock the number of modules per inverter to ONE (1 module for each inverter), right? 
3) How would it be the "Electrical Configuration" at System Design page, for a system with 3 x 1.5KW Microinverters, each one with 4x430W module (DC to AC ratio: 1.11) connected to each microinverter, PLUS another microinverter that will have only ONE 430W module. So we´ll have FOUR microinverters, being THREE with 4x430W modules connected and ONE inverter with only 1x430W module connected (13 modules of 430W each).

Thanks a lot !

Hi Lester,

We build SAM's module and inverter libraries from the Excel workbooks published on the CEC Solar Equipment Lists website at the time of the SAM release. Those lists change frequently, so it is possible that equipment has been added or removed since the November 2020 release date. We will update the libraries for the next release, planned for Fall 2021. You can use the technique described in this post to model a PV system with modules or inverters not in the SAM libraries:

sam.nrel.gov/forum/forum-general/2768

I am not familiar with the APSystem inverters, but from my brief review of their website and a datasheet for one of their products, it appears that the inverter designed for four modules has four MPPT inputs. For modeling purposes, you could treat that inverter as four separate microinverters.

Given that assumption, to model your system, I would use the following inputs on the System Design page:

Number of Inverters = 13
Modules per String in Subarray = 1
Strings in Parallel in Subarray = 13

Best regards,
Paul.