Example #7 Influence of core gap on the winding losses

9/1/04 Pg. 2 Open PExprt application This example will show how the core gap fringing flux affects the winding losses.

9/1/04 Pg. 3 Select File/New for a new project Select “Converter Based Buck Inductor” component from the list of components and click on “OK” button

9/1/04 Pg. 4 Select Ferroxcube library for design Drag the Ferroxcube library from the “Stock Library” and drop it on the “Design Library” to assign it

9/1/04 Pg. 5 Define the required converter parameters Input Voltage: 48 V Switching Frequency: 100 kHz Output Voltage: 12 V Output Power: 100 W Inductor Current Ripple: 100 % of Iaverage

9/1/04 Pg. 6 Start the design process Use “Calculations/Start Design Process” or click on the button at the toolbar

9/1/04 Pg. 7 Allow PExprt selecting the core, wires and core materials Click on “Yes” button

9/1/04 Pg. 8 Designing the component… Save the project after the design process

9/1/04 Pg. 9 Display the ID # in the list of results Double click on the list to bring up the “Customize List of Results” window. Then check the “ID #” box and select OK. An addition column appears on the left side to give each design a number

9/1/04 Pg. 10 Deleting all designs except for the last one in the list, which is #1272 Remove all the designs of the list except the last one 1. Select the design clicking on it 2. Right mouse button click (or use “delete” key in the keyboard) 3. Select “Delete” in the pop-up menu

9/1/04 Pg. 11 After deleting the designs, only the last one should be in the list Only one design left in the list of results

9/1/04 Pg. 12 Create two copies of the design Creating copies of the design 1. Select the design clicking on it 2. Right mouse button click 3. Select “Create a Copy” in the pop-up menu to create design # Save the component 4. Repeat steps 2 and 3 to create another copy: design #1274

9/1/04 Pg. 13 Selecting the design to be modified Select the first design in the list #1272

9/1/04 Pg. 14 Use “Modeler/Generate Model” menu or click on the button at the toolbar Modifying the winding strategy of the designs Select “Open PExprt Modeler [PEmag]” Click on “OK”

9/1/04 Pg. 15 Modifying the winding strategy of the designs PExprt Modeler Widow

9/1/04 Pg. 16 Modifying the winding strategy of the designs Select “Windings” tab Expand the component Library (double click) and select the “Winding Setup” element (double click)

9/1/04 Pg. 17 Modifying the winding strategy of the designs Define a 1.5 mm central margin tape Click on “OK” Margin tape in included between the bobbin and the winding

9/1/04 Pg. 18 Generating the FEA based model Select “Modeler/FEA based Modeler (2D)/Start 2D model generation” or use the tool bar button

9/1/04 Pg. 19 Generating FEA based models of the designs Click on “OK” Click on “Start” The model may take about 2 minutes to be generated

9/1/04 Pg. 20 Modifying the winding strategy of the designs Exit the PExprt Modeler application Save the component Do not delete the previous model files.

9/1/04 Pg. 21 Generating FEA based models of the designs Select the second design in the list #1273

9/1/04 Pg. 22 Use “Modeler/Generate Model” menu or click on the button at the toolbar Generating FEA based models of the designs Select “FEA based Model without capacitive effects” Click on “OK” Note this design has not been modified since the PExprt Modeler was not accessed.

9/1/04 Pg. 23 Generating FEA based models of the designs Click on “OK” Click on “Start” The model may take about 2 minutes to be generated

9/1/04 Pg. 24 Recalculating winding losses with the previously generated models Use “Calculations/Recalculate Winding Losses” menu or click on the button at the toolbar Select “NO” in order to use the 2D models previously generated

9/1/04 Pg. 25 Explore results The icon is modified in order to notify that the winding losses of these designs have been recalculated with the 2D (FEA based) model. The 2D effect of the gap is considered This design was the original one (losses were calculated analytically). The 2D gap effect is not considered

9/1/04 Pg. 26 Explore results Each design can be explored in detail For example, select the second design

9/1/04 Pg. 27 Explore results Explore the performance results

9/1/04 Pg. 28 Explore results Explore the constructive results

9/1/04 Pg. 29 Explore results: Comparing results