Flux-Simulink co-simulation: Example

Introduction

To permit to the user to implement the co-simulation between Flux and Matlab-Simulink, a detailed example, with the main stages to be implemented, is given in the following sections.

Example description

The example represents two cables, one supplied with sinusoidal voltage, the other with triangular voltage.

If the cables are placed close enough, there will be a electromagnetic influence of one upon the other, and the currents will not be perfectly sinusoidal or triangular, respectively.

Therefore, the purpose of the study is to regulate the current in the cable supplied with sinusoidal voltage to obtain a sinusoidal current.

Flux project

The geometry, mesh and physics are given below.

Preparation of I/O parameters in Flux

The input and output parameters are described as follows :

I/O name Description Type Value / formula
Input parameters V1

Supply voltage of the cable 1

associated to the voltage source Source1

I/O parameter,

multiphysics

 Reference value =0
V2

Supply voltage of the cable 2

associated to the voltage source Source2

I/O parameter,

multiphysics

 Reference value = 0
Output parameters I1

Current in the cable 1

(current in the solid conductor M1 )

 I/O parameter defined by a space formula I(M1)
I2

Current in the cable 2

(current in the solid conductor M2 )

 I/O parameter defined by a space formula I(M1)

Generation of component in Flux

To generate the component of the Flux – Matlab Simulink coupling:

Step Action
1

Open the dialogue box:

  • Click on Generate component for Matlab Simulink coupling in the Solve menu
2 Define the name of component ( for example CABLES)
3

Choose the input parameters:

  • Select V1
  • Select V2
4

Choose the output parameters:

  • Select I1
  • Select I2
5 Validate by clicking on OK
→

A CABLES.F2MS file has been created.

The Flux project has been duplicated and registered under the name: CABLESF2MS.FLU

Preparation of the Simulink model

To prepare the Simulink model:

Step Action
1

Open Matlab:

  • Starting from the Flux supervisor in the Solve menu, click on Simulink
2 Open Simulink by clicking on
→ The Simulink library is open.
3

Make a new model :

  • Point on New and click on Model in the menu File
→ A blank window will appear
4

Register the model:

  • Click on Save in the menu File
  • Allocate a name (for example model_cables )
5

Place the section « Coupling with Flux »

  • Take the library « Coupling with Flux » in the library Flux_Link and place it in the window model_cables
6

Characterize the section « Coupling with Flux »:

  • double click on the section
  • in the tab Project:
  • allocate the name of the project CABLES.F2MS
  • tick or not Multiplexed inputs/outputs (in function of the desired representation)
  • in the tab Solve:
  • tick the case Automatic delay
  • tick the case Flux console display
  • validate the characterization of the library by clicking on OK
7 Place, characterize and connect the other necessary libraries according to the model in the figure below.
8 Save the model by clicking on Save in the menu File
→ The preparation of the Simulink model is complete

Configuration simulation

Configure the simulation parameters with a time interval from 0 to 0.6 s and the time step set at 0.001 s and launches the solving process.

During the solving process the actions carried out in Flux are visible in the Flux console, which has appeared in a new window, and the information on the solved steps are also displayed in the window " Command Window" of Matlab.

Analysis of results

The results can be analyzed in Matlab – Simulink, as well as from Flux in the project CABLESF2MS_SOLVED.FLU

Graph results in Matlab-Simulink Graph results in Flux