Hi,

the significance of  a "DUMMY_DER" variable is that this variable was used inside a "der" function or market as state (for example stateSelect=StateSelect.prefer). During the index reduction algorithm it was found that this variable is not a state in the meaning of an independent variable (by a constrained equation) and this variable kind was changed from "STATE" to "DUMMY_STATE". (same for derivatives.)

If a optimized code of a linear circuit will contain $DER depends on the used library. If the library manage to use a minimal state form no $Der will occur, but normally this is not practical for  the design of the library.

For further information please have a look at https://www.modelica.org/events/worksho … ttsson.pdf for example.

I am sorry if my question appears silly. Can I choose library/libraries in such a way as there will not be $DER terms? Till now I am selecting the whole 'Modelica' library while executing 'bltdump'. The command I am using is 'omc +s +d=bltdump filename.mo Modelica'. But in case of describing & optimizing linear electrical circuits is there any alternative/specific libraries using which the description may not be minimal state but will not contain $DER terms?

Regards,
AC.

Why is the $DER term problematic for you? This is just a silly prefix for a variable.

By the way +d=bltdump also works with .mos files and if you use +d=dumpindxdae you get the equations after all optimisation phases.

Thanks Frenkel TUD for your answers. My problem with $DER is that I want to use the description generated by Modelica optimizer from a C programing environment where I will use the variables generated by Modelica as the variables and there the '$' sign though being a just a silly prefix for a variable will create problem if used in a variable name.

Regards,
AC.