Andes speed calculation about andes HOT 11 OPEN

Hi Jose,

Thanks for reporting. It looks like an issue with ANDES. I will look into it and let you know.

from andes.

@jinningwang It looks like an issue with GAST. One or multiple sign errors creat a positive feedback, which causes the frequency to rise even without any disturbance.

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@jd-lara
Hi,
After inspection, it is caused by inappropriate GAST parameters VMAX and VMIN. After converting to the ANDES input file, those two parameters are set to be 0.5, and they limited the GAST.LAG to match the GAST.pout.
Setting them to 1.1 and 0 can solve the issue.

@cuihantao
Hantao,
Should we consider some auto-correction for this?

Regards,
Jinning

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from andes.

@cuihantao I am not sure this is the root cause since in PSSe and in PSID we don't get any input errors.

from andes.

Hi,

The bug is caused by that the LAG reaching the lower limit. I enabled the adjust_lower of GAST, so the limit can be autocorrected. For more information on limit adjustment, you can check https://docs.andes.app/en/stable/release-notes.html?highlight=adjusted%20limit#v1-5-7-2021-12-11

The fixed code can be found in the PR:
https://github.com/cuihantao/andes/pull/319

Regards,
Jinning

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@jinningwang It's a separate issue. The immediate cause of the error is the wrong treatment of PSS/E dyr data for GAST. The fix is pushed to my develop.

@jd-lara After fixing the parser issue, the results are now the same as PSID:

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The result looks pretty much like that from PSID but is slightly different in the magnitude:

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Thanks @cuihantao, I will continue the testing once it's merged

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The result looks pretty much like that from PSID but is slightly different in the magnitude:

That's probably right, we are chasing a bug in the governors that is creating relatively small differences in the frequency. Testing with ANDES is easier than with PSSe :)

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Lol, thanks! Good luck with the bug chase! It could be both annoying and fun :)

My master branch is updated with the fix.

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