Use multi-MPPT feature

[Tavasez]

Hello!

I'm having a big school project, so i'm using PVsyst 6. This is my first time using it and i have some questions.

I'm making a grid-connected system, with 9 strings and 7 modules in each string. The modules are Sharp Solar ND r25QA5 - 250W. The invertor is Ingeteam Ingecon Sun 12.5TL-Sm. When i click "Use multi-MPPT feature" and select 4 MPPT inputs, it automatically gives me Ïnverter with 3 MPPT", the program says "The invertor power is slightly oversized" wich i read in tutorial that is normal. My question is, what is the meaning of "Use multi-MPPT feature" and "Bumber of MPPT inputs"? Doest it mean that i have 4 invertors?

Thank you in advance!

[André Mermoud]

The number of MPPT's is a physical feature of each inverter.

In PVsyst, you normally use the MPPT features of the inverter.

But in a pre-study, you have the opportunity to get rid of this and consider the inverter "as a whole", i.e. one MPPT input (option "Uses MPPT" unchecked).

Now in one sub-array, you have to specify the number of strings, and the number of MPPT inputs used for this sub-array.

For example if you have 8 strings, you can distribute them on 4 MPPT inputs. If the inverters have 1 MPPT, this will mean 4 inverters; with 2 MPPT per inverter: 2 full inverters; with 3 MPPT per inverter, 1 inverter and a third.

You can use other MPPT inputs in other sub-arrays.