Symbolic linearization of Modelica model

Questions
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1

Hi,
I’ve tried to linearize a Modelica model compose of thermal conductors and capacitors.
This model uses the Modelica.Thermal.HeatTransfer.Components.HeatCapacitor and ThermalConductor and other models/blocks from the Modelica standard Library.

I want to linearize it in a symbolic way by taking into account symbolic parameters of this model. It works well with 1 or 2 parameters however when I tried to add a third one to the parameter list, it fails.
Does anyone knows if there is some limitation for this.
Regards,
Gilles

2

Hi,

Would it be possible to publish your model?

3

Hi, thanks for the reply.
I will try to simplify a bit my model before publishing it.
However making more trials give me few hints. The source of the issue may come from :

  • parameters in vector form are not so well handle,
  • records for parameter are not so well handle too. You need to expand the record when using it as a symbolical parameter
        Not working, keep in numerical form :
            WSMLinearize[model,Method → {“SymbolicDerivative”,“SymbolicParameters” → {“rec”}}]
        Seems to work :
            WSMLinearize[model,Method → {“SymbolicDerivative”,“SymbolicParameters” → {“rec.item1”,“rec.item2”}}]
  • encapsulation of record (nested records)?

In addition the WSMLinearize function seems to be a bit unstable. Sometimes when using it, it fails, but when you re-run the function, it works.
Gilles