We will be performing a major infrastructure and web site ugprades on Friday, September 27th 8:00 am - 5:00 pm MST (UTC -7).

The website will be down during that time.

Warning in CSP Empirical trough model

  • alvaro_ralbertini
  • Topic Author
More
05 Mar 2020 14:36 #8022 by alvaro_ralbertini
Warning in CSP Empirical trough model was created by alvaro_ralbertini
Hello all,

It is great to have the possibility to communicate with all of you through this Forum.
I am curious about a warning I receive in some of my CSP Empirical Trough simulations. I am aware these are not errors and the outputs are still calculated, but I would like to know what they mean and how to decode the logs. 

One example of the warning follows:
time 2538000.00 { Test Trough 2 }:
Warning - Empirical trough (805) model exceeded interal iteration limit

I realize the warnings are related to the weather input I provide. However, the weather check macro always gives positive results to the all weather files I try.I understand maybe the simulations constraints for the convergence are too strict in this case. Is there a way to relax them? Also, is there a way to decode the time Information and find in which step is my Simulation not converging? Do you have any ideia why could be the reason of this?

Any comments and help from all of you will be much appreciated!
Attached is the weather file and the csp Project I used for this Simulation.
I wish you all a very nice day! 

Best regards,
Alvaro
Attachments:

Please Log in or Create an account to join the conversation.

  • pgilman
More
13 Mar 2020 16:12 #8036 by pgilman
Replied by pgilman on topic Warning in CSP Empirical trough model
Dear Alvaro,

SAM's performance models use iterative methods to solve for values in internal calculations. The error message you saw says that one of these methods failed to converge on a solution within the number of iterations allowed by the person who wrote the algorithm. Unfortunately, it does not say what value it was attempting to calculate, but the model did assign a value so it could complete the simulation. The value may be a temperature or power value at some node of the system for a single time step so using a default value would not have a significant effect on the model output. In general, if there are only a few of these messages out of the 8,760 time steps in an hourly simulation, you can ignore them. If there are error messages for a large number of time steps, it may indicate that there is a problem with one or more inputs that need to be fixed.

Best regards,
Paul.

Please Log in or Create an account to join the conversation.

Moderators: pgilman
Powered by Kunena Forum

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

NREL Home

NREL Research

Follow NREL

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.