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Error message "Turbine calculations do not converge" in HAMMER

Hi everyone.

I'm a new user of the software and I'm currently try to model an instant load rejection case for a Francis turbine.

When I run the transient analysis I get the error message "Turbine calculations do not converge. Check electrical torque or four quadrant curve values". I selected the four quadrant curve (between the three possible choices) according to the specific speed obtained from the manufacturer data, so I'm pretty sure it's right.

Any suggestion?

Parents
  • Hello Carlo,

    You may want to take a look at the Turbine Curve for the turbine, as well as the other results. For reference, you can check the turbine sample model that comes with Bentley HAMMER. The sample can be found at C:\Program Files (x86)\Bentley\HAMMER8\Samples\Turbine_Example.wtg.

    Further information on using turbines at the following link: communities.bentley.com/.../using-turbines-in-bentley-hammer

    If this doesn't help, we will need a copy of the model to look into this further. There are two options for sharing your model files on Communities. If you would like the files to be visible to other members, compress the files into a zip file and upload them as an attachment using the ‘Advanced Reply editor’ before posting. If your data is confidential, you can follow the instructions in the link below to send it to us via Bentley Sharefile. Files uploaded to Sharefile can only be viewed by Bentley.

    communities.bentley.com/.../7079.be-communities-secure-file-upload

    If you upload the model to Sharefile, please let us know the name of the file so we know it is available.

    Regards,
    Scott
  • Thanks for your answer Scott,

    One of my colleagues uploaded the model files (a zipped folder named "Hammer_CLA). Please reply directly to him with your suggestions.

    Thanks for your help.
Reply Children
  • Hello,

    I did some testing of the model files you provided. I would recommend double-checking the input, particularly the turbine curve (which is used to define the initial head and flow from the turbine), the specific speed, and the moment of inertia. I noticed that if a difference specific speed was used that the results converged. I also noticed that if the moment of inertia is set to 1000 kg m^2 with the specific speed that you had original selected that the results converged as well.

    Regards,
    Scott

    Answer Verified By: Carlo Rossi