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 | 1 | initial version |
Hi,
The fact that pssexcel succeded in exporting to excel when you had results with small numbers makes me wonder if it's wrong with how the .sav file is setup before the load flow is executed. It's hard to say however without seeing what kind of output you are getting (flows and voltages). You say that you have high flows and low voltages, are they all 0 or 0.2 pu something? What do you mean with high flows, way over 150 %? For me that makes me think of two things that you ought to double check:
1) Your solution might've converged to the low voltage high flow solution or as my power system lecturer used to say "went past the "nose" of the PV-curve". You can see on this picture: www. openelectrical.org/wiki/images/5/56/PV_Curve.PNG that for one active power flow solution there are two different voltages (in theory atleast). One with voltages around 1 pu the other with low voltages and really high flows like 200% and upwards.
2) Do your contingencies contain alot of islands? That would also give you low or 0 voltages (assuming no generators in the islands or higher loads than generators). have you selected to export or not export results from islands (cannot remember if it is possible to do but check the API).
For me I've had some trouble with PSS/E converging to the low voltage high flow solution when I do major changes to my system in one go instead of taking it in steps. For example changing a phase shifting transformer from -30 to 30 degrees, instead I did it in steps of 10 or 20 degrees and it was fine. Hope this serves as some help.
| | 2 | No.2 Revision |
Hi,
The fact that pssexcel succeded in exporting to excel when you had results with small numbers relatively low flows makes me wonder if it's wrong with how the .sav file is setup before the load flow is executed. It's hard to say however without seeing what kind of output you are getting (flows and voltages). You say that you have high flows and low voltages, are they all 0 or 0.2 pu something? What do you mean with high flows, way over 150 %? For me that makes me think of two things that you ought to double check:
1) Your solution might've converged to the low voltage high flow solution or as my power system lecturer used to say "went past the "nose" of the PV-curve". You can see on this picture: www. openelectrical.org/wiki/images/5/56/PV_Curve.PNG that for one active power flow solution there are two different voltages (in theory atleast). One with voltages around 1 pu the other with low voltages and really high flows like 200% and upwards.
2) Do your contingencies contain alot of islands? That would also give you low or 0 voltages (assuming no generators in the islands or higher loads than generators). have you selected to export or not export results from islands (cannot remember if it is possible to do but check the API).
For me I've had some trouble with PSS/E converging to the low voltage high flow solution when I do major changes to my system in one go instead of taking it in steps. For example changing a phase shifting transformer from -30 to 30 degrees, instead I did it in steps of 10 or 20 degrees and it was fine. Hope this serves as some help.
