System Advisor Model (SAM)

CSP running error: SVAL LOOKUP ERROR trnsys.user_trdsrc

steelhg
Topic Author

30 Apr 2013 16:53 #1576 by steelhg

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

Hi Paul,

Thank you very much, those are very helpful. I will let you know if I need further help.

Best,

G

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Paul Gilman

30 Apr 2013 18:51 #1577 by Paul Gilman

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

In the process of writing the SamUL script, you may discover the formatting issue with the EPW file that causes SAM's simulation to crash.

I would recommend using a standard TMY3 file and the TMY3 user's manual from the NSRDB's TMY3 website as references to make sure that the values that you write to the TMY3-formatted file are consistent with the standard TMY3 data format.

And, one clarification: The TMY3 file format is different from a typical year dataset. The TMY3 file format describes the arrangement and formatting of data in the file. A typical year dataset is one year of data that represents a multi-year period. You can store either typical year data, or data for a single year in the TMY3 file format.

Best regards,
Paul.

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steelhg
Topic Author

01 May 2013 00:01 #1578 by steelhg

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

Thanks Paul!

I have finished running the 200ish weather files in TMY3 format, but still have about 10ish weather file that have problems to go through. I received error messages but I can hardly tell what have caused the problems. I think format problems should be solved by the EPW to TMY3 conversion.

What are the other possible data errors for CSP simulation?

I figured out that any space in "Station Name" and "Station State" is one problem, I fixed this one. What else?

The number of decimal digit of the data input?

Is there any limit on the "Site Evevation", "GHI", "DNI", "DHI", "Dry-bulb", "Dew-point", "RHum", "Pressure", "Wspd" and "Alb"? I mean will extreme value, for example, elevation > 3000m, GHI > 1400, Wspd > 12, Dew-point < -30, etc impact the simulation? This list includes almost all the parameters needed to create the TMY3 file.

The CSP simulations are very helpful but I feel SAM is a bit "mysophobia" about the data format which sometimes makes me frustrated in debugging those error messages. I hope it can be more compatible and robust.

Anyway, thanks for the support and I appreciate the immediate response.

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Paul Gilman

01 May 2013 16:31 #1579 by Paul Gilman

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

Hello,

Because of the number of calculations involved in SAM simulations, it is often difficult to track down the source of a simulation failure.

In addition to possible number formatting issues in the weather file, there are some system design parameters that may cause simulations to fail. For example, if a parabolic trough system's solar field is excessively large compared to the power block and storage system capacities for a given location, for the physical trough model, simulations fail if the iterative collector defocusing algorithm does not converge.

As for the weather data limits, it is possible that an extreme value for the solar radiation, temperature, or humidity data could cause one of the CSP models to fail. Unfortunately, when the simulation fails, SAM does not have information about the specific value that caused the failure -- all it knows is that a calculation or algorithm produced an invalid result.

It seems like you may need to go through the 5% or so of your weather files that are causing simulation failures to determine whether there are problems with data in those weather files, or whether there is something about the system design parameters that is causing simulations to fail under those weather conditions.

I agree that troubleshooting these problems is time-consuming and can be frustrating.

Best regards,
Paul.

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