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Algebraic equations in QSS Solver

2016-02-09
2021-12-23
  • Anton de Villiers

    Is it possible to model a system containing algebraic equations in QSS Solver using any of the built-in QSS solvers (QSS, LIQSS, etc.)? I have a system in which some of the equations are algebraic. I can simulate the problem using the DASSL solver, but not with the QSS based solvers.

    I also investigated the case where a system was created consisting only of algebraic equations. I was unable to simulate the system with any of the available solvers in QSS Solver.

     

    Last edit: Anton de Villiers 2016-02-09
  • Federico Bergero

    Hi Anton, it IS possible to model a system containing algebraic equations and simulate it using both QSS and DASSL. The issue is that they have to be given in ordered and in an Ordinarry Differential Equation form.
    For example
    model A Real a,b; equation a=b+sin(time); der(b)=1-a; end A;

    In this example the variable a has to be "defined" before its use. The first one is a algebraic equation.

    The second thing you mention is because the QSS solver needs at least one continous state variable, if not there is nothing to integrate.

    Please write us if you need any help.
    Fede

     
    • He Yingliang

      He Yingliang - 2018-03-15

      Dear Dr. Bergero
      I am a student. I am learning QSS method and using QSS Solver. However, I am not good at μ–Modelica.I was wondering if you have developed an extension of the OpenModelica compiler which converts models from Modelica to μ–Modelica. Thank you for your time.
      Sincerely,
      Yingliang He

       
  • Stephen Irving

    Stephen Irving - 2021-12-23

    Hi,I can't run any models with QSS Solver normally.Can't generate C file is displayed.
    Any suggestions?

     

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