Robin Vincent

Actually, it is even trickier than that. For both values, changes are detected if any of the 1st 4 characters is changed. It usually means 1 digit for module quality (the "-" counts as a character) and 2 digits for the LID. Then, if the value is less than 0.1 point different from the default, it is set to the default value. The final value is then stored and, as you mentioned, only 1 digit is displayed. This is obviously not ideal, and we should harmonize the behaviors and make sur the number of digit displayed matches the number used. Nevertheless, such an accuracy (1/10000) is definitively not necessary in the 1st place.

This issue is due to a bug in the automatic string attribution to each MPPT (triggered when changing something in your system or when clicking on reinitialize inverter list). It should be solved in the 8.0.5. Meanwhile, to be able to simulate your system you can try deleting and adding back each inverter one by one until the error message disappear. Make sure your system is fully defined before doing so, as any modification on the subarrays definition will trigger a new string attribution,which could lead to the issue reappearance.

Yes this is planned for a future version of PVsyst (at least with optimizers), but I cannot give you any timeline for it.

No you cannot set heterogenous strings in PVsyst. The closest workaround would be to have subarrays with strings containing +1 and-1 modules relative to your odd-strings definition, and connect them to the same inverter. It won't be exactly equivalent, and only work if the total number of modules connected to the inverter is even. But at least the total DC power would be correct, and the impact on the different component efficiencies and threshold limited.

Sub-hourly simulation is a simulation with a time step lower than 1 hour. It may be useful to correctly account for non linear phenomenon such as clipping and curtailment. It is currently not directly available in PVsyst, even though workaround exist to run pseudo sub-hourly simulation https://www.pvsyst.com/wp-content/pdf-tutorials/pvsyst-tutorial-v8-pseudo-sub-hourly-simulation-en.pdf or to have a better clipping correction estimation https://www.pvsyst.com/help/physical-models-used/grid-inverter/subhourly-clipping-correction.html?h=clipping. In both case, sub-hourly weather data is necessary.

Please contact the support by email at support@pvsyst.com with your project (project => export project) so we can have a better understanding of what is happening.

The results export is restricted to the same time step as the simulation, which is set to 1 hour. Smaller time steps will be available once the sub-hourly simulation is.

No, the simulation itself is still hourly-based. We only extract additional info from sub-hourly weather data to correct the clipping losses.

With unlimited sheds, pretty much all the parameters you mentioned will impact the near shadings losses. You may be able to find more detailed information in the help page for diffuse losses with tracking systems : https://www.pvsyst.com/help/project-design/shadings/calculation-and-model/diffuse-losses-with-tracking-systems.html#tracker-diffuse-shading-definition-window-from-version-730

This issue must have been fixed by now, in PVsyst 8.0.2.

The backtracking strategy avoids direct mutual shadings, but not the other irradiance components. If you extract the simulation results with all the near shadings variables, you should be able to see that the Beam loss due to near shadings (ShdBLss) are equal to 0, but not the diffuse (ShdDLss) and albedo (ShdALss) components.

Yes, all you need is a text file containing all the commands you want to pass through. Each command must be on its own line. For instance, to convert a weather data file, you can set up a text file (TestCLiCmd.txt) containing the following lines : -icf:path/file.csv -imf:path/file.MEF -isf:path/file.SIT -omf:path/file.MET And then simply run the command : PVsystCLI convert-meteo -cof:TestCLiCmd.txt from the same directory.

PVsyst integrates a set of rules, as requested by Huawei, to authorize or not some inverters / optimizers combination. A side effect is that if you create your own inverter it will not be compatible with any Huawei optimizers. You'll be able to use Sun5000 inverters with MERC optimizers in PVsyst8, which should be released in a matter of days or weeks.

Dear R. Polášek, Thank you for bringing up this issue. We are aware that the multi-string attribution on a single MPPT with Huawei inverters/optimizers currently has some limitations. If you're working with just one subarray, this shouldn't pose any problems. However, given your situation with multiple subarrays, unfortunately, it will not function as expected. We are actively working on a fix, which will be implemented in PVsyst V8. Until then, you won't be able to simulate your project as it is currently configured. As a temporary solution, we recommend ensuring that each inverter is connected to only one subarray. This should allow you to proceed with your simulation in the meantime.

There is no real justification for limiting the number of periods to 5. It will be changed in a future PVsyst release.