module layout - compared to near shade only

[deblynn]

Hello,

I am using the module layout tool for the first time (version 6.25). My intention is to see the shading according to the module string wiring details.

When I run the model with near shading according to strings, 100%, and without the module layout, I get 2.7% near shadings irradiance loss, and 4.4% electrical loss according to strings.

When I run the same model after completing the module layout section, I get 25.1% near shadings irradiance loss, and 0 electrical loss.

This does not seem right, perhaps I am doing something wrong in the module layout. Any advice?

[deblynn]

Follow up questions:

I noticed that when you import from the 3D near shading drawing, it brings in all the "tables", but does not maintain their position relative to each other. 2 of them were overlapping. Could this perhaps explain the high shade loss that resulted initially?

I spaced them out further and ran it again, getting 2.5% near shadings irradiance loss, and 1.7% electrical loss, which is lower losses than the original model with 100%, according to strings.

So, does the relative position of the "tables" in the view screen matter, or is all the shading calculated according to the positions in the near shading dialog?

Also, regarding bypass diodes and MPPT, does the calculation assume that the inverter can "find" a maximum power point if the curve has multiple peaks and valleys?

Thanks!

-Debbie

[André Mermoud]

It is normal that the electrical loss computed from the Module layout is lower than the crude approximation of the option "Shadings according to strings", which gives an upper limit.

This is the reason of the parameter "Fraction for electrical effect", which you can adjust using the Module layout information.

The relative position of the tables when defining the strings for the Module layout have no effect on the shading calculation. This arrangement is only a convenient way for defining all the tables at a time. We have improved this view recently.

Since version 6.32, when the Pmpp of the shaded string is below the minimum voltage VmppMin of the inverter, the calculation searches for the second maximum within the voltage range.