Preparing a Maxwell Equivalent Circuit Model for Twin Builder

The following steps outline the process for preparing and using a Maxwell Equivalent Circuit model in Twin Builder.

1. Create a model of the component in Maxwell, including the geometry and material properties.
2. Define the appropriate boundary conditions under Boundaries.
3. Define the model excitation under Excitations.
   • When assigning the excitation as Current, enter the Current Excitation Name, the Value as an independent variable, the Type as Solid or Stranded and click OK.
     Note:

     This step must be performed for each terminal or group of terminals are intended to be included on current excitation definitions.

4. Define the appropriate model parameters, assigning them under Parameters.

1. When considering exporting a matrix into the circuit design, you must assign a Matrix:

• Right-click Parameters and select Assign > Matrix.
• In the Matrix dialog box, select the Include check box for each of the existing sources to be included into the matrix calculation.
• Use the Post Processing tab to specify turns and group together windings to better represent the physical winding topology.

2. When considering exporting a specific force calculation into circuit design as a measure of the mechanical through quantity of a linear motion design, a solid object must be selected and a Force parameter defined:

• Select a portion of the geometry on which to calculate the force.
• Right-click Parameters and select Assign > Force.
• In the Force Setup dialog box, enter a Name for the force parameter.
• Select the Type of the force computation, either Virtual or Lorentz.
• Use the Post Processing tab to set a coordinate system of reference.

3. When considering exporting a specific torque calculation into circuit design as a measure of the mechanical through quantity of a rotational motion design, a solid object must be selected and a Torque parameter defined:

• Select a portion of the geometry on which to calculate the torque.
• Right-click Parameters and select Assign > Torque.
• In the Torque dialog box, enter a Name for the Torque parameter.
• Select the Type of the torque computation, either Virtual or Lorentz.
• Select the Axis about which to calculate the torque, and the rotational sign.

5. Solve the problem in Maxwell to ensure that the Maxwell project is set up correctly. Errors in the Maxwell project cannot be corrected from Twin Builder.
   Note:

   See the Maxwell documentation for detailed information on creating and solving the Maxwell model.

6. Add a Solution Setup under Analysis. The Maxwell simulation end time (Tend) must be greater than or equal to that of Twin Builder.
7. Add a Parametric Setup within Optimetrics.

The parametric setup must have the selected independent variables varied to form a complete nested parametric solution. For example, if two variables are entered as Current with the variations 1, 2, 3 and second independent variable Position with the variations 0, 10, 20 then the parametric table will have for first variation value of the Current 1, a sweep of all available variations for Position, and so on. So the very first three rows within the parametric table represent the very first parametric nest solution and it will be sufficient to extract an equivalent circuit to be imported into circuit design.

8. Save the Maxwell Project.
9. Ensure that Twin Builder has runtime access to Maxwell on the same computer or another computer on the network.
10. Establish a link to the Maxwell Equivalent Circuit model project, and place a Maxwell Equivalent Circuit Model component on the Twin Builder schematic.
11. Connect electrical and mechanical pins of the Maxwell Equivalent Circuit model component to other models on the Twin Builder schematic.
    Note:

    Equivalent Circuit models exported from Maxwell that have mechanical pins must be connected by these pins to a mechanical subsystem having a ROTATIONAL _V nature. For versions of Maxwell lower than Version 10, Service Pack 1, this must be done using a Domain to Domain component. For later versions, the connection can be made directly.

12. Run the simulation in Twin Builder.
13. Switch back to Maxwell if you need to update the model design.