Simulating 2 strings with different number of modules

[SoftwareTester]

For a system with 21 modules I would like to simulate attaching 1 string of 10 and 1 string of 11 in parallel to an inverter having only 1 MPPT (and input).

How do I do that?

What if an inverter has 1 MPPT but 2 inputs?

Using the tool Electrical behaviour of the heterogeneous arrays I found out on june 21st mismatch loss with 1 string of 10 and 1 string of 11 will be about 1.6%.

[André Mermoud]

You can't do that in PVsyst.

This is not a good system in the reality. The strings connected to a given MPPT input should be homogeneous.

The 2 inputs of the inverter are just connectors. They are connected together in the device.

NB: however you are partially right: with only 2 or very few strings the mismatch is not so important.

But in the tool "Electrical behaviour of the heterogeneous arrays", try for example to define 37 modules as 5 x 6 modules and 1 x 7 modules: you will see a secondary Maximum power point, and the MPP tracker may clip on it, and never reach the true MPP !