Creating the DC-DC Converter Simulation Model

  1. Place and arrange all components shown in the figure above. (The schematic from the previous step can be extended.) Alternator, Powertrain, Battery, Capacitor, DC-DC Converter, Load, and Wire are VHDL-AMS models from the vhdlams_tutorial folder under System Libraries in the Component Libraries window. The OmniCaster model is inserted automatically by drawing a connection from the Triangular Wave component to the Load. The Triangular Wave is a model from the Time Functions folder under the Tools folder of the basic_vhdlams library. Type Ctrl+G to place a ground node.
  2. Connect the models. Connect the components as indicated in the figure, setting the beginning, the corners, and the end of a wire with the mouse.
  3. Define wire parameters. For each wire model, double-click the wire symbol to open its Properties dialog box. Click in the r_nom Value field, and enter the corresponding resistance value. Click OK to apply the changes.
  4. Define parameters of the capacitor. Double-click the capacitor symbol to open its Properties dialog box. Click in the c_nomValue field, and enter 10m as capacitance. Click OK to apply the changes.
  5. Define parameters of the load. Double-click the load symbol to open its Properties dialog box and change the model name to load_42. The model uses the admittance architecture (default setting). Click OK to apply the changes.
  6. Define parameters of the triangular wave. Double-click the triangular wave model to open its Properties dialog box. Click in the appropriate Value fields and enter 0.05 as offset, 0.05 as amplitude, and 0.2 as frequency value. Click OK to apply the changes.
  7. Define the simulation parameters. Choose Twin Builder>Add Solution Setup>Transient to open the Transient Analysis Setup dialog box, and set the default value for simulation End Time to 5 seconds, Min Time Step to 1ms, and Max Time Step to 1 s. Click OK to apply the changes. Right-click the Analysis icon in the Project Manager and select Add Solution Options. On the TR tab set Integration formula to Trapezoid. Click OK to apply the changes.
  8. Place and arrange two 2D Rectangular Plots to display simulation results. Select Draw > Report > Rectangular Plot, and then click and drag to place and size the plot on the sheet.
  9. Open the simulation Output list. Choose Twin Builder>Output Dialog to open the Output dialog box.
  10. Define the simulation output quantities. Click the “+” next to the components to reveal the list of available quantities. Check the output boxes of load_42.i, load_42.v, and load_42.ctrl_ramp to add these to the list of displayed quantities. Click OK to apply the changes.
  11. Add traces to the plot. Double-click the on-sheet plot to open the Report dialog box. Select each of the output quantities defined above and change the scaling used for the traces as shown in Results - DC-DC Converter”. Click Add Trace to add it to the plot. Click Close to apply the changes.
  12. Repeat the steps 9, 10 and 11 for the second plot, but check the box of bat_soc.soc_out as output.
  13. Define the simulation parameters. Choose Twin Builder>Add Solution Setup>Transient to open the Transient Analysis Setup dialog box, and set the value for simulation End Time to 5 seconds, Min Time Step to 1ms, and Max Time Step to 1 s. Click OK to apply the changes. Right-click the Analysis icon in the Project Manager and select Add Solution Options. On the TR tab set Integration formula to Trapezoid and Maximum number of iterations to 45. Click OK to apply the changes.
  14. Save the sheet. Choose File>Save As, enter a file name and directory, and click OK.