1. Maxwell 3D Transient

2. Overview
Transient solver computes magnetic fields in the time-domain (instantaneously at each time step)
Formulation is based on a current vector potential in solid conductors, and a scalar potential over the entire field domain
Field equations are strongly coupled with circuit equations to allow voltage sources and/or external driving circuits
Quantity solved is the magnetic field (H) and the current density (J) while magnetic flux density (B) is automatically calculated from the H-field
Derived quantities are forces, torques, energy, and inductance

3. Overview (cont.)
Non-linear behavior of magnetic materials is considered
Permanent magnets are considered
Excitations can be sinusoidal or non-sinusoidal including:
Currents and current densities in conductors
Voltages and currents applied to windings
Permanent magnets
Two types of conductors can be considered:
Solid: eddy currents are considered
Stranded: eddy currents are neglected

4. Boundaries
Thin, perfectly insulating sheets between touching conductors.
Same as Neumann, except that current cannot cross the boundary.
Insulating
Notes:
No Balloon Boundary available
Planes of symmetry in periodic structures where H is oblique to the boundary.
The H-field on the slave boundary is forced to match the magnitude and direction (or the negative of the direction) of the H-field on the master boundary.
Matching (Master and Slave)
Planes of geometric and magnetic symmetry.
Field behaves as follows:
Odd Symmetry (Flux Tangential) — H is tangential to the boundary; its normal components are zero.
Even Symmetry (Flux Normal) — H is normal to the boundary; its tangential components are zero.
Symmetry
Ordinary field behavior. Initially, object interfaces are natural boundaries; outer boundaries and excluded objects are Neumann boundaries.
Natural boundaries — H is continuous across the boundary.
Neumann boundaries — H is tangential to the boundary and flux cannot cross it.
Default Boundary Conditions (Natural and Neumann)
Used to model…
H-Field Behavior
Boundary Type

5. Sources
The current density in a conductor.
Current Density and
Current Density Terminal
The terminal (sheet object) for a conductor.
Current
The terminal (sheet object) for a winding.
Coil Terminal
Type of Excitation
Source
The terminal (sheet object) for a current density source.
Note: In addition, permanent magnets serve as sources of magnetic fields

6. Overview of Sources
Schematic Option

7. Source Details
A DC “current” (solid or stranded) can be assigned to a terminal
A “current density” can be assigned to a 3D object while “current density terminal” is assigned to the 2D sheet object inside of that object
Coil terminals allow for the most sources including: voltages, currents, external circuits, or sources which vary with time
Coil terminals will automatically report flux linkage and induced voltage plots vs. time under Post Process/ Transient Data
For a coil terminal, “Model/Winding Setup” must be used to complete the source setup

8. Winding Setup
Use “Model/ Winding Setup to group windings and assign sources
To group coil or conductor terminals, select a terminal from the Coil/Conductor list on the left, and choose Group.
To ungroup terminals, select a winding group from the Winding list on the right, and choose Ungroup.

9. Winding Setup (cont.) Select the winding from the Winding list.
To assign a source to a winding:
Select the winding from the Winding list.
Select the type of source you want to assign: Current, Voltage, or External.
Select either Strand or Solid.
Enter in extra parameters, such as total turns.
For a current or voltage source, you can assign a function. If you want to assign a function, do the following:
1) Choose Function to open the Function window
2) Select or define a function and then choose Done
3) Choose Assign. The source information appears in the Winding list next to the winding name.
Choose Assign and Exit to complete winding setup

10. External Circuits Step 1: Step 3:
Edit / Edit External Circuit and launch Schematic Capture
Step 3:
When exiting Schematic editor specify sources to be either: time, position, or speed dependent
Step 2:
In Schematic editor each winding appears as inductor symbol

11. Finalizing Source Setup
Completed sources appear in list box in left side window

12. Setup Solution Options
The mesh must be manually created for all transient projects, unless the project is copied from a previously solved Magnetostatic or Eddy Current project
Set the Stop time and Time Step appropriately for the simulation (~20 timesteps per cycle)

13. Setup Solution Options (cont.)
Choose Save fields time step for post processing a particular timestep later to create plots
After solving at least one timestep, a post processing macro can be created. Select this macro by checking Use Macro and specifying the macro.
Any quantities that are written using the Append button in the calculator will appear under Solutions > Transient Data as a new .dat plot file

14. Setup Solution – Motion Setup
Choose Set Band to specify the band object
Switch the moving and stationary objects by clicking on Switch Moving Objects

15. Setup Solution – Motion Setup
Specify Rotational or Translation motion
Set Anchor Point and End Point for motion
Set Positive and Negative limits for motion

16. Setup Solution – Mechanical Setup
For constant velocity, uncheck Consider Mechanical Transient
For varying velocity check Consider Mechanical Transient and input:
Initial Velocity
Moment of Inertia
Damping
Load