CSP running error: SVAL LOOKUP ERROR trnsys.user_trdsrc

steelhg
Topic Author

29 Apr 2013 18:46 #1570 by steelhg

CSP running error: SVAL LOOKUP ERROR trnsys.user_trdsrc was created by steelhg

Hello, I'm trying to run "CSP Trough No Storage" and "CSP Trough 6th Storage" using the China weather files in "epw" format downloaded from here .

I have no problem to run the residential and commercial PV run using the same weather file.

I think I have the same problem as in Ryan's post .

I tried use "epw" weather files from other countries to do the runs and failed with the same error message. It works OK with most of the system "tm2" weather file.

I attached one weather file for my simulation, would you advise how to fix the weather file to make it ready for the "CSP" run? Should I convert the "epw" file to "tm2" file? How?

Thank you very much!

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steelhg
Topic Author

29 Apr 2013 20:20 #1571 by steelhg

Replied by steelhg on topic CSP running error: SVAL LOOKUP ERROR trnsys.user_trdsrc

After studying the weather file definition/format carefully, I noticed that the only missing data in the "epw" file but needed for CSP simulation is "Wet bulb temperature (°C)". I assume SAM can't calculate "Wet bulb temperature (°C)" from "Dry bulb temperature (°C)" and "Relative humidity(%)", otherwise this should not be a problem. Am I right? Anybody has such problem before? Thanks.

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Paul Gilman

29 Apr 2013 20:22 #1572 by Paul Gilman

Replied by Paul Gilman on topic CSP running error: SVAL LOOKUP ERROR trnsys.user_trdsrc

Hello,

It is difficult to tell what might be causing your simulations to fail. I took a quick look at the file you mention using the data viewer (from SAM's Location and Resource page), and it looks like there may be a few hours of the year when the humidity value is greater than 100%. That may be causing some of the equations in SAM's heat transfer calculations to fail.

If you are having trouble with the EPW files, you may want to consider purchasing data from one of the companies that provide weather data in formats that SAM can read.

Best regards,
Paul.

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steelhg
Topic Author

29 Apr 2013 22:15 #1573 by steelhg

Replied by steelhg on topic CSP running error: SVAL LOOKUP ERROR trnsys.user_trdsrc

Hi Paul,

Thank you for your response.

I checked the problem you mentioned and wrote a query in SAM to replace all the humidity numbers that are great than 100 to 99. I then run the CSP simulation again and received the same error message.

I then tried some tm2 system weather file for example "Atlanta", it has some points with "Relative Humidity" larger than 100% is good for CSP simulation. Therefore, relative humidity should not be the problem for the error message.

Purchasing data is not an option for current research, I think I already have the weather parameters SAM needs. Just a question how to adapt EPW file for CSP simulation.

Best,

GH

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steelhg
Topic Author

29 Apr 2013 23:55 #1574 by steelhg

Replied by steelhg on topic CSP running error: SVAL LOOKUP ERROR trnsys.user_trdsrc

Hi Paul,

I tried the data from EPW and using "Create TMY3 File" to create TMY3 file and then run the CSP simulation, it worked!

Then my question: Is there any SAM-UL embedded function so I can create bulk TMY3 files? I have 200 weather file to simulate, it will be a pain if I have to create TMY3 file one by one.

Any suggestions will be helpful.

Thank you!

Best,

G

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Paul Gilman

30 Apr 2013 15:38 #1575 by Paul Gilman

Replied by Paul Gilman on topic CSP running error: SVAL LOOKUP ERROR trnsys.user_trdsrc

Hello,

The result of your test suggests that my guess that there is a problem with the data in the EPW file was wrong. Because the data worked in the properly formatted TMY3 file that you created in SAM, it seems instead that there is a formatting problem with the EPW file that you were able to correct by using the TMY3 Creator.

Yes, you can use the CustomizeTMY3() function in SamUL to convert your weather data to the TMY3 format. It works in the same way as the TMY3 Creator: You start with a "base" TMY3 file, and the function replaces columns of data with values from an array. That function only writes the weather data (columns of 8,760 rows) to the file, not the header data with the time zone, latitude, longitude, and elevation values that SAM also needs for sun angle calculations. You will have to write those values to the file separately.

If you try this approach and have questions about your script, please ask them here and I will do my best to help.

Best regards,
Paul.

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