Mohamed_M's profile - activity

Thanks @perolofl

I am trying to model relay trip action to trip loads/feeders for over-frequency conditions in PSSE dynamic simulations. However, I can't seem to find any suitable model. Most relays are based on underfrequency

LDSHBL, LDSHOW, LDSHZN, LDSHAR, LDSHAL

The only over-frequency relay I found are the:

FRQDCAT, and FRQTPAT,

However, they only disconnect generators, or the whole bus. Is their any over-frequency relay that would trip a load or a percentage of a load?

You go to

"File->Save Case as->Sequence Data"

and then select the options and file name that you want

Three things to consider:

1-Do a flat-run with no contingencies to see if the issue happens even without fault (if yes, then one of your models is not configured correctly, and it would likely be the first generator having large swings in voltage)

2-Do a contingency in a completely different area of the system. If the issue persists, then it is likely de to improper simulation parameters, but if it solves normally, then the issue is local to that area where you had your original contingency

3-There is a possibility that nothing is wrong with the simulation and your case can't handle that specific fault and you end up with large voltage swings followed by blackout/brownout.

The Model User Guide for Generic Renewable Energy System Models by EPRI is a good starting point for turning the generic models in general. However, matching them to a specific UDM would require either a lot of trial and error, or the documentation of that UDM to have a better idea of its parameters and how they map to generic model

You should always convert case before doing simulation. Not sure why you got "No active table model for in-service machine" instead of giving you error regarding not using converted case.

Hi @TheNewGuy, The underscores sometimes automatically change into italic. You can use highlight these lines and click the code button (the one with 101010) and that should show them correctly

Thanks for updating the answer

Hi @patelamarh, Your answer has some formatting issues because underscores change into italic font, . Can you edit your answer and enclose variable names with undersore with a code or quote block so that it appears correctly?

Okies. I will try it and see.

Hi ACCC experts,

I tried using the SKIP command in MON and SUB files and I failed in getting the desired results even though I followed how the PSSE manual describe using them to the best of my abilities. Can someone please provide an example of how to use SKIP properly.

My "appear to be" non-working MON and SUB files:

MON file

MONITOR BRANCHES IN SUBSYSTEM ABC

SKIP
999001 TO 999003
999001 TO 999004
999002 TO 999005
999002 TO 999006
END

END

SUB file

SUBSYSTEM 'ABC'
    JOIN
    AREA 123
    KVRANGE 100 999
    SKIP 888001
    SKIP 888002
    SKIP 888003
    END
END

Am I using the SKIP correctly? or is there more details to it?

I still see the skipped transmission lines and buses in the ACCC results. So, I have to be doing something wrong, but I can't figure it out.

Apologies for posting something that is not a question, but I have seen way too many good questions with no votes, and way too many answers that correctly address the concerns with no votes or "Accepted" checkmark (some even have comments indicating that they solved the issue!).

So, I just wanted to make this post as a PSA to everyone to please help the community be even better by voting up questions that you find relevant or well-written, and voting up answers that addresses your concerns (and more importantly, accept the answer if you are the one who posted the question).

Thanks perolofl. Is there a source or guide on how to approach other governors? I found some other PSSE governor models where the equation still holds, and some where it holds in GSTR simulation, but not in grid-connected. While other times, it does not apply at all

Based on this PPSPY post "What is the base value for the generator GREF? " the GREF is represented as

 GREF = DROOP*PMECH

However, I sometimes encounter cases where this equation is not giving the expected answer compared to PSSE simulations. Is this GREF equation a general equation for all governor models? or is the equation different for different models?

For any modeling, general rule is "model what is needed to appropriately model the dynamics of the model". So, if you are trying to model the slow phenomena of wind machines then the details you mentioned are important. However, if you are only interested in faster dynamics (e.g., faults, LVRT, HVRT) then the mechanical details can be assumed to be almost constant and not significantly affecting the results of the faster dynamics

If you own a PSSE v34:

open the case using PSSE v34

Go to File->Save Case As-> Power Flow Raw Data, Previous Versions

Select PSSE(R)E - 33 and click OK to save the RAW file

Open the RAW file in PSSE v33 and save it as SAV

If you do not own a PSSE v34:

You need to ask the person who supplied the sav file to send a v33 sav file, or v33 raw file (using the above steps)

You can do the following: 1-Open the .CNV case in PSSE 2-Go to File->Open. Then open the DYR file 3-Go to the Dynamics Data tab and see if the models are loaded correctly to the generator rows 4-Check the Output Bar in PSSE and look for any errors if step3 showed missing generator models

Hi,

The following two playlists are a perfect spot to start as a beginner in PSS/E:

PSS/E Software (by Power System Experts)

PSS/E by Power System Simulation

You might be overwhelmed in the beginning by the amount of features in PSS/E but as you progress you start realizing that based on your specialization or interest you will only need to learn a small subset of what PSS/E has to offer.

As for coding in python for PSS/E automation, a perfect place to start is this forum and specially the answers and programs written by JCONTO and his code package: PowerSystemByJConto

In addition to perolofl's answer, another reason to get the

"No active table model for generator ... at bus ...[..... 132.00] -- RUN will not be accessible"

is when the DYR models for these generators have mistakes that prevented PSSE from loading them successfully

Thanks. Your fix works for me, but now larger SLDs are very slow to traverse. However, it is better than having the bug

The same issue happens for me in both PSSE 34 and 35 (using AMD Radeon)

From PSSE 34 and 35 a lot of major changes happened in .dll and Fortran (32bit to 64bit, and many older IVF became obsolete). So, if you jumped from 34(or earlier) to 36 then that could be the issue. However, if you went from 35 to 36 then I don't know what could be the issue.

If you indeed went from 34 or earlier to 36, then you could read more about OneAPI and their updated Fortran compiler, because you would need OneAPI (as opposed to Intel Visual Fortran) to compile your Fortran codes

Is there a way to convert .raw files into a .py (or .idv) script instead of importing the raw file?

I know that I could record the loading of the raw file and have the .py/.idv command (psspy.rdch("...")), which is my "Plan B". Instead, I am looking for transforming the .raw into an equivalent .py (or .idv)

However, since no one answered then it seems that there are no quick ways to do such a change

My main reason is for ease of reading. I am doing multiple changes to my sav case, and all the changes (except two) are stored as .py. So, they could be merged into a single .py file. So, I wanted to know if there was a simple way to make an equivalent .py for them so one .py shows all the changes