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Questions regarding FluxTubes, HysteresisModelComparison #2248
Simulating the model Modelica.Magnetic.FluxTubes.Examples.Hysteresis.HysteresisModelComparison using JModelica result in that the variables:
are chosen as states. These are poor choices for states as their magnitude are around 1e-4 and because of that they are missing nominal values. Would it be possible to include nominal values for these?
A better choice, in this model, for states would be
is this true in general? If so, would it be possible to set state select on these?
We did have a look at this ticket, but unfortunately at the moment we don't have capacities to implement and test other state variables. However, selecting flux density instead of magnetic flux as state variable should be possible in principle.
From a numerical point of view, it is very obvious that the flux densities are better choices of states in the library example and will lead to more accurate results in any simulation environment.
In addition, all of the 3 hystereses models are actually written as states by the modeler (with a der() on the flux density B ), so it would basically be a confirmation of what I see as the intent of the modeler to add stateSelect.prefer. Phi as a variable is structurally equivalent, scaled by a constant, but a worse scale basically always. Alo Dymola gets faster with B as a preferred state in all 3 models.