Modeling modules with power optimizer covering multiple roof faces

Hi,

I am investigating which software can model solaredge technology like the following typical string with solaredge inverter and optimizers:

1: 13 modules, 6 on roof face 1 with tilt=30,azimuth=180, 7 on roof face 2 with tilt=30, azimuth=90
2: each module is equipped with a power optimizer
3: partial shading covers 0 to 4 modules of the 6 modules on roof face1 from hour 12 to hour 15.  (shading just for illustration purpose, does not need to be exact)
4: partial shading covers 0 to 5 modules of the 7 modules on roof face2 from hour 13 to hour 18. (shading just for illustration purpose, does not need to be exact)
5: 13 modules go into 1 solaredge optimizer inverter

I am using SAM UI but I eventually will use pvsamv1 module of the SDK. My question is, is pvsamv1 capable of run performance analysis for module level of shading and orientations? Here in this string, because the modules are on 2 different roof face, can SAM handle this properly? 

When I have shade factor on each individual module, because SAM is not at individual module level, I might need to average over the subarray to get subarray level shading. But on 2 different roof face the shading is very different. How does SAM handle 2 roof faces in one string?

Thanks I know these requirements are high wishes. I looked at PVSyst, it also does not handle module level analysis. But it seems to (but actually not) handle multiple orientations of modules in one string for SolarEdge technology.

Does any solar design/simulation software package do this? I wish SAM do this and the SDK provide more friendlier interface for modeler to run analysis.

Thanks,

Shuping

Hi Shuping,

For an array with sections that have different orientations (or tracking), you can divide the array into subarrays on the System Design page. In your example with two roof faces, you could use two subarrays: Subarray 1 for the modules on roof face 1 and Subarray 2 for the modules on roof face 2.

On the Shading and Layout page, there is a set of shading inputs for each subarray, so you can model the shading of each subarray separately.

SAM assumes that each subarray can operate at its own operating voltage. In the physical system, this would require either in inverter with separate input connections for each subarray, or power electronics between the modules and inverter to convert voltages. SAM does not explicitly model DC/DC converters or other power electronics, but you can account for conversion losses for different topologies (string inverters, module-level microinverters, DC/DC converters, etc.) on the Losses input page. You can also use the "PV Subarray Voltage Mismatch" option at the bottom of the System Design page to choose how to account for voltage mismatch between strings.

SAM calculates the operating voltage and other parameters for each subarray based on the number of modules per string for each subarray. It is not possible to model a single string of modules where some modules in the string have different orientations than others.

Best regards,
Paul.