multiple orientations, single mppt

[wilsonxsun]

Hi all,

I am trying to run a simulation of a 100kW system.

The system contains 1 central inverter with 1 MPPT.

However the panels have 3 orientations that are slightly different to each other.

I understand with 2 orientations, i can use the mixed #1 and #2 option, however what if there were 3 orientations connected to one tracker, is there a way to run an successful simulation?

Please let me know.

Thank you.

[André Mermoud]

PVsyst only treats the mix of 2 orientations on a given MPPT input.

If you have 3 orientations, you should define an average between two of them. The results will not be very different.

[solar_dummy]

PVsyst only treats the mix of 2 orientations on a given MPPT input.

If you have 3 orientations, you should define an average between two of them. The results will not be very different.

 

When do you mean with average between them? Lets consider an extreme case where we have 2 orientations: -90S and +90S. The average would be 0S (??) but the result couldn´t be more misleading.

I am trying to compare mismatch losses of central inverters and string inverters for minor differences in orientation.

Thanks in advance.

[André Mermoud]

The simpler way is to redefine your inverter with 3 MPPT inputs, and attribute one sub-array to each input.

The mismatch between orientations (i.e. between strings in different orientations) is usually very low (a fraction of %). You can check this by defining one sub-array with a "mixed" orientation. Here the calculation is correct, as it uses the mix of both I/V curves.

[H.Tannous]

Hi 
I have three orientations and would like to use 1 invertor with 3 MPPT inputs for that but I am not sure how to assign a single invertor to all three subarrays.

I tried selecting the same invertor for each orientation with 3 MPPT but kept getting the following message: "you should define at least one string per inverter or MPPT input?

Can you please advise?

Kindly,

Hadi

[André Mermoud]

In your Subarrays definitions, you have defined 3 MPPT in each sub-array. If so, you should indeed define at least 3 strings in each subarray.

Now in your case you have one string per Subarray, so that should define one MPPT input in each subarray.