CODEWITHSUNDEEP
openmodelica
Gabriele Galli
Gabriele Galli

Reputation: 115

import an existing Modelica block contained in MSL in a model

I am new in using OpenModelica.

I have a model that simulates the behavior of a battery. It is composed of different DAEs. Now it works using a constant current but I am trying to get some results using a time-varying current. I noticed that in Modelica -> Electrical -> Analog -> Sources there is a huge quantity of different current inputs that I could use to define the variable (Real) current in my model.

Is there a way to introduce in a model an already-existing block?

For instance, I am trying to give as input in my model the stepCurrent (contained in Source library) but I am getting back an error.

This is the way I coded:

model battery

//definition of variables and parameters

// II1C is the current

import Modelica.Electrical.Analog.Sources.PulseCurrent; Real II1C = PulseCurrent(I = 10, period = 500, width = 50,offset=0);

equation

// DAE system which is also a function of II1C.

end battery;

This is the error message I got:

[1] 19:22:01 Translation Error [BatteryModelDischarging: 15:1-15:68]: Looking for a function .Modelica.Electrical.Analog.Sources.PulseCurrent but found a model.

[2] 19:22:01 Translation Error Error occurred while flattening model BatteryModelDischarging

Is there a way to make this work?

Thank you so much in advance,

Kindest regards, Gabri

Upvotes: 0

Views: 66

Answers (1)

user12812532
user12812532

Reputation:

Yes, there are different ways to introduce a model from a library into your battery model.

An easy solution to make your model "work" is the following (it checks, at least; I am not sure it will do what you want it to do)

model Battery

//definition of variables and parameters

// II1C is the current
  Modelica.Blocks.Sources.Pulse currentSource(amplitude = 10, period = 500, width = 50, offset=0); 
  Real II1C;

equation

currentSource.y = II1C;

// DAE system which is also a function of II1C.

annotation(
    uses(Modelica(version = "3.2.3")));
end Battery;

where

  • Modelica.Blocks.Sources.Pulse is the path in the Library where the model Pulse is located
  • currentSource is the name of the instance of the Pulse model in your Battery model
  • (amplitude = 10, period = 500, width = 50, offset=0) are the parameters that modifies the default behavior of the Pulse model (normally called modifiers)
  • currentSource.y = II1C; under the equation section is the way to assign the ouptut of the Pulse model (.y) to the variable II1C you instantiated as Real II1C;

Notice though that the Pulse model has nothing to do with the electrical domain, it is just a general signal source. That is, it is up to you to integrate it in your model in a way that makes sense physically; besides, it might be inefficient regarding the modeling and simulation performance.

Perhaps DrModelica could be a good place to start understanding not only the technical aspects of the Modelica language, but also good practices to model with it.

Upvotes: 1

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