Resistance in Component has to be constant?

Numerical methods and mathematical models of Elmer
Post Reply
MartinHoeijmakers
Posts: 37
Joined: 22 Oct 2017, 21:03
Antispam: Yes

Resistance in Component has to be constant?

Post by MartinHoeijmakers »

Hi all,

I try to simulate the dynamic behavior of the short circuit of a synchronous machine, starting from no load.
A well-known method is to make an electric circuit in the electric machine and make a short circuit at the terminals. I made such a circuit by means of the Circuits and Dynamics Solver.
The idea is to start with a very large resistance (no-load condition) which is made very low at the moment of the short circuit.

I tried to change the resistance of a component by

Code: Select all

Component 1    ! aPlus
  Master Bodies (1) = Integer 4    ! aPlus
  Coil Type = String Stranded
  Number of Turns = Real 2
  Resistance = Variable time
    Real
         0.00000 10.0
         0.03626 10.0
         0.03627 0.01
         1.00000 0.01
    End
End
I got the error
ERROR:: ListGetConstReal: Constant cannot depend on variables: Resistance

A trick that worked was to change the Electric Conductivity of the Material of the corresponding Body as a function of time. However in my case that would mean that I would have to make such a change in my material library. That is a quite dirty trick (for me).

Does anyone have a better idea to make a change in an electric circuit?

With kind regards,
Martin Hoeijmakers
raback
Site Admin
Posts: 4812
Joined: 22 Aug 2009, 11:57
Antispam: Yes
Location: Espoo, Finland
Contact:

Re: Resistance in Component has to be constant?

Post by raback »

Hi,

I just modified the component resistance so that it can be a function of global variables (time being the most typical one). So any binary compiled in the future should have this. Have fun!

-Peter
MartinHoeijmakers
Posts: 37
Joined: 22 Oct 2017, 21:03
Antispam: Yes

Re: Resistance in Component has to be constant?

Post by MartinHoeijmakers »

Hi Peter,

Thank you again for the quick response. I will keep an eye on new binaries.

Kind regards,
Martin
Post Reply