Electrical Heating of a Busbar Solved with LiveLink™ for SOLIDWORKS® and LiveLink™ for MATLAB®

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Electrical Heating of a Busbar Solved with LiveLink™ for SOLIDWORKS® and LiveLink™ for MATLAB®

This model analyzes the resistive heating of a busbar designed to conduct a direct current from a transformer to an electric device. Some geometry parameters are set with MATLAB® variables and automatically updated in SOLIDWORKS®.

The geometry for the simulation, displayed in Figure 1, includes the coupling components for one cell, and a section of the inter-cell busbar that is connected to the power source. It consists of the top of the anode with four central columns holding copper rods attached to copper bars.

Figure 1: The geometry of the anode to busbar coupling used in this example.

This version of this introductory tutorial demonstrates the use of LiveLink™ for MATLAB® together with LiveLink™ for SOLIDWORKS®.

The instructions in this example assume that LiveLink™ for SOLIDWORKS® Application Libraries has been installed together with COMSOL.

Model Definition

You can read a complet physics description in the LiveLink™ for SOLIDWORKS®Application Library, see the application Electrical Heating Of ABusbar Assembly.

The current model performs the same analysis as the one defined in the LiveLink™ for SOLIDWORKS®Application Library. Here the parameter sweep is performed in MATLAB®.

Results and Discussion

Figure 2 shows the average temperature of the busbar plotted against its width and length. The temperature distribution in the device for selected combinations of the studied parameters is shown in Figure 3.

According to the results increasing the surface area of the busbar by increasing its length and width leads to a lower temperature, as the surface area available for cooling increases.

Figure 2: Surface plot of the busbar maximum temperature versus the rod diameter and the busbar width.

Figure 3: Temperature distribution in the busbar.

Note About the COMSOL Implementation

Using nested loops in MATLAB it is easy to study multiple cases combining different values of the geometry parameters.

To set up this simulation you can start with the application library file busbar_llsw_llmatlab.mph, which you can easily load into MATLAB, where you continue to implement the script for running a multiple parameter sweep.

Wrapper functions used by the script:

•

to load the model .mph file.

•

to display the model geometry.

•

to evaluate average quantities in the model.

•

to create plots.

LiveLink_for_MATLAB/Tutorials/busbar_llsw_llmatlab

Modeling Instructions — MATLAB®

1

In SOLIDWORKS open the file , which you find if you browse to the application’s LiveLink™ for SOLIDWORKS® Application Library folder.

2

You now have two possibilities to continue:

•

Enter each command, starting at step 3 below, at the MATLAB command line.

•

Paste the full model script, included in the section Model M-File, into a text editor, then save the file with a “.m” extension, and finally run this file in MATLAB.

3

Start by loading the .mph file that contains the simulation of the device using the LiveLink™ for SOLIDWORKS®:

model = mphopen('busbar_llsw_llmatlab');

4

Display the current geometry in a MATLAB figure:

The geometry in the MATLAB figure should be equivalent to the following one:

5

Update the parameters list in the CAD package:

cad = model.geom('geom1').feature('cad1');

cad.updateCadParamTable(true, true);

6

Change the width of the busbar to 200 mm by entering:

model.param.set('LL_D1_Sketch1_angle_connector_sldprt',200);

7

Display the updated geometry in a MATLAB figure:

This produces a MATLAB figure with a geometry similar to the one below:

8

Since in this example you are using a MATLAB for-loop for the parametric sweep, you can deactivate the parametric sweep in the model object by entering the following:

model.study('std1').feature('param').active(false);

9

Next, define two MATLAB variables that contain the values to use for busbar length and width parameters:

size_rod = size(rod,2);

width = 60:20:100;

size_width = size(width,2);

10

Start a for-loop for the rod diameter parameter, and at each iteration change the value of the parameter rod in the model object. Type:

for j = 1:size_rod

model.param.set('LL_D1_Sketch2_rod_sldprt',rod(j));

11

Start a second for-loop for the width parameter:

for i = 1:size_width

12

Create a wait bar to display the progress of the iterations:

str = sprintf('Iteration No %d...',(j-1)*size_width+i);

h = waitbar(0,str);

waitbar(((j-1)*size_width+i)/(size_rod*size_width), h);

13

To update the value of the parameter width in the model object and compute the solution with the updated geometry enter the commands:

model.param.set('LL_D1_Sketch1_angle_connector_sldprt',width(i));

model.sol('sol1').run;

14

Evaluate the maximum value of the temperature, close the wait bar and close the second for-loop:

T_max(i,j) = mphmax(model,'T','volume','selection','geom1_cad1_Copper_dom');

15

Close the first for-loop:

16

Display the plot group pg2:

model.result('pg2').set('data','dset1');

mphplot(model,'pg2','rangenum',1)

17

Finally, display a surface plot of the average temperature against the length and width parameters:

[xx,yy] = meshgrid(rod,width);

h = surf(xx,yy,T_max);

xlabel('rod[mm]');

ylabel('width[mm]');

zlabel('Tmax[K]');

Below you find the full script of the model. You can copy it and paste it into a text editor and save it with the “.m” extension. To run the script in MATLAB make sure that the path to the folder containing the script is set in MATLAB, then type the file name without the “.m” extension at the MATLAB prompt.

model = mphopen('busbar_llsw_llmatlab');

cad = model.geom('geom1').feature('cad1');

cad.updateCadParamTable(true, true);

model.param.set('LL_D1_Sketch1_angle_connector_sldprt',200);

mphgeom(model);

model.study('std1').feature('param').active(false);

size_rod = size(rod,2);

width = 60:20:100;

size_width = size(width,2);

for j = 1:size_rod

model.param.set('LL_D1_Sketch2_rod_sldprt',rod(j));

for i = 1:size_width

str = sprintf('Iteration No %d...', (j-1)*size_rod+i);

h = waitbar(0,str);

waitbar(((j-1)*size_width+i)/(size_rod*size_width), h);

model.param.set('LL_D1_Sketch1_angle_connector_sldprt',... width(i));

model.sol('sol1').run;

T_max(i,j) = mphmax(model,'T','volume',...

'selection','geom1_cad1_Copper_dom');

model.result('pg2').set('data','dset1');

mphplot(model,'pg2','rangenum',1);

[xx,yy] = meshgrid(rod,width);

h = surf(xx,yy,T_max);

xlabel('rod[mm]');

ylabel('width[mm]');

zlabel('Tmax[K]');