Bugs with saving Ohmic losses, and batch mode report

[allison.mueller]

Hi folks - some errors I saw with my latest project using v7.2.8:

a) I needed to run a simulation with 0% MV transformer losses (they are included in our particular inverter). It ran correctly, as confirmed by the report file, but if I reopen the variant(s), the values revert to 0.1% and 1.0% (values we typically use). So, the values are not saving correctly within the project.

b) ^ Same kind of issue for the AC LV losses. I ran a batch with 0.1% loss, but the variant file itself shows 0%.

c) If using the Windows setting for the batch file delimiter style, the columns get offset incorrectly. Labels need to be shifted to the left starting with the "Error" column.

[Stéphane Metz]

Hi allison.mueller,

Regarding point "c", could you send us by email at support@pvsyst.com the erroneous batch file you mentioned? Also, what's your Windows settings delimiter?

[Bruno Wittmer]

Dear allison.mueller,

Just for clarification of point b): Did you try to change the AC losses in batch mode and it did not work, or did you change the variant and it did not save the changes as in a)?

I tried to reproduce the behavior you describe in point a), but did not succeed. When I change AC and/or Transformer losses, and save the variant, it is stored correctly and I find the new values when reopening the variant.

Could it be that you have several sub-arrays with different cable and transformer configurations, and that you changed only one of them, while the others remained the same?

If that is not the case, could you please send us an example where this happens, so that I can reproduce the error and fix it?

Please note also, that in batch mode you can only change the transformer resistance losses (copper losses), but not the iron loss. Therefore the global transformer losses will never become zero in the batch mode.

Similarly, in the batch mode you can only change the AC cables between inverter and MV transformer, the MV line cannot be changed with the batch mode.

[allison.mueller]

Hi allison.mueller,

Regarding point "c", could you send us by email at support@pvsyst.com the erroneous batch file you mentioned? Also, what's your Windows settings delimiter?

 

I'm now on 7.2.11 and I have not had this re-occur since the update. If it does, I will reply back here and send you files. Thank you for your response!

-Allison

[allison.mueller]

Dear allison.mueller,

Just for clarification of point b): Did you try to change the AC losses in batch mode and it did not work, or did you change the variant and it did not save the changes as in a)?

I tried to reproduce the behavior you describe in point a), but did not succeed. When I change AC and/or Transformer losses, and save the variant, it is stored correctly and I find the new values when reopening the variant.

Could it be that you have several sub-arrays with different cable and transformer configurations, and that you changed only one of them, while the others remained the same?

If that is not the case, could you please send us an example where this happens, so that I can reproduce the error and fix it?

Please note also, that in batch mode you can only change the transformer resistance losses (copper losses), but not the iron loss. Therefore the global transformer losses will never become zero in the batch mode.

Similarly, in the batch mode you can only change the AC cables between inverter and MV transformer, the MV line cannot be changed with the batch mode.

Sorry, I did not see that there was a reply to this question. Thank you for your reply. To answer your questions:

- The AC loss issue did not involve a batch run. However I have not yet seen this re-occur. I will notify you if it does. We did not have the situation you described above, with several sub-arrays.

- However, the transformer losses are still consistently not saving properly when they are set to 0% (this is just a normal single simulation, no batch work involved). As an example, exiting out of the project and then reopening it will reproduce the problem. The project also shows this problem if it is exported, then opened by another person. Switching between variants has also caused this to show up (e.g., switch to variant 2 then back to variant 1). Please let me know if you are unable to reproduce and I can perhaps send some more details. We use this setting quite often so it would be a big help if the problem can be tracked down.

Thank you,

Allison

[Bruno Wittmer]

Dear Allison,

Thank you for the clarification, I am now able to reproduce the behavior of point a).

We will fix this for one of the next releases.

We are sorry for the inconvenience, and thank you for reporting the issue.