New Functionality in Version 4.3

Rotating Machinery, Magnetic 3D and Mixed Formulation

  • The Rotating Machinery, Magnetic physics interface is now applicable to three-dimensional models and can be used to model motors, generators, and other electrical machinery in 3D.
  • A mixed potential formulation has been implemented for this physics interface. In addition to the magnetic vector potential formulation, it now supports a scalar potential formulation (similar to the one used in the Magnetic Fields, No Currents interface), applicable in domains without current flow. The two formulations can be used together in the same model and are particularly effective for the modeling of electrical machinery with moving parts. Suitable interface conditions are set up automatically to ensure seamless integration of the two formulations.

Coil Features in 3D and automatic current calculation

  • The Coil features (Single-Turn Coil Domain, Multi-Turn Coil Domain), previously available only for 2D and 2D axisymmetric models, are now available for 3D models as well.
  • The 3D Single-Turn Coil Domain introduces an additional dependent variable to ensure correct conservation in the domain. A Magnetic Fields interface with a 3D Single-Turn Coil Domain feature can effectively replace the Magnetic and Electric Fields interface in many applications.
  • The 3D Multi-Turn Coil Domain represents a homogenized model for a coil constituted of a great number of tightly-wound wires. In addition to simple built-in coil shapes, such as Linear or Circular, the new Coil Current Calculation study step can compute automatically the path of the wires for coils with complex geometry.
  • The 3D coils are compatible with the new 3D Rotating Machinery, Magnetic interface.

Porous Media Mixture Model for AC/DC

  • The mixture model for Porous Media and Archie’s Law, previously available only for the Electric Currents interface, are now available for all the interfaces in the AC/DC Module.
  • For Porous Media, a dedicated subnode can be used to computed an averaged value of the electrical conductivity, relative permittivity, and relative permeability of mixtures of up to five materials.
  • A dedicated subnode is available to compute the electrical conductivity in saturated nonconductive porous media using Archie’s Law.

S-Parameters computation for Terminals and conversion

  • Terminals now support a Terminated (terminating impedance) condition, in addition to the existing Current, Voltage, and Circuit conditions. The value of the impedance can be specified manually for each terminal or can be set globally in the physics interface node.
  • When solving a Frequency Domain study with this condition, the Terminals will automatically define an S-parameter matrix variable that can be evaluated using a Global Matrix Evaluation node in postprocessing or exported using the Touchstone Export functionality.
  • It is now possible to convert lumped parameter matrices in the Global Matrix Evaluation node (for example, from admittance to impedance). By specifying a characteristic impedance, it is also possible to compute the S-parameter matrix from Z and Y and vice versa.
  • When performing a Terminal sweep and a frequency sweep in the same study, the plots of the computed lumped parameters or S-parameters as functions of the frequency are created automatically.

other improvements and changes

The following changes apply to all the interfaces in the AC/DC Module, unless explicitly stated:

  • All the interfaces now support the new multiphysics Infinite Elements under the Definitions node, introduced in version 4.2a. This improvement simplifies the creation of multiphysics coupling between interfaces in models using infinite elements.
  • Features now distinguish between Solid and Non-solid domains. This setting defines their behavior when the domains are subject to, for example, rotations or deformations.
  • In 2D axisymmetric models, it is now possible to add specialized boundary and point condition on the symmetry axis (for example, Line Charge on Axis for Electrostatics).
  • Improved handling of out-of-plane thickness for 2D models. In addition to the global Out-of-plane Thickness setting in the physics interface node, it is now possible to change the thickness of individual domains or boundaries using specialized features.
  • For the Electric Currents, Shell interface, specialized features can be used to locally change the thickness of the shell.

Backward Compatibility vs. Version 4.2a

  • Due to a general refactoring and optimization of the entire AC/DC Module, obsolete variables that were hidden but were still available in previous versions have now been removed. Among these are the old coil variables and lumped parameters. In 4.3, all the variables defined by coil features follow the template XCoil_<name>, where X is the variable name (V for voltage, Z for impedance, and so on) and <name> is the value written in the Coil Name field. Plots and expressions using the old variables must be updated.
  • The AC/DC Module now uses the new-style Infinite Elements, available under the Definitions node. 4.2a and earlier models containing the old-style Infinite Elements (in the physics interface) will retain them when opened in version 4.3, but it will not be possible to add more old-style Infinite Elements. It is advised to replace those features with the new-style Infinite Elements whenever possible.
  • The Rotating Machinery, Magnetic physics interface is now defined using the Material frame. However, Rotating Machinery, Magnetic interfaces in 4.2a or earlier models, if opened in 4.3, will still be defined using the Spatial frame, to ensure that the results of the model do not change between versions.

Backward Compatibility vs. Version 3.5a

Change in Dependent Variables

Version 4 has a comprehensive set of inductive formulations based on the magnetic vector potential. These cover all modeling situations except for situations with strongly nonlinear conductivity (superconductors) for which magnetic field H-based formulations are more suitable.

The 2D formulations based on the magnetic field H as dependent variable in version 3.5a are not yet included in version 4.3. A full set (3D, 2D, and 2D axial symmetry) of H-based formulations is planned for a future release.

Models created in version 3.5a that are built using an H-based formulation will not include any physics interface settings when opened in version 4.3. Geometrical data and definitions (constants and expressions) will be imported and the physics can manually be added using the (vector potential-based) Magnetic Fields physics interface.

Pair Boundary Conditions

The Contact Resistance, Transition, and Perfect Magnetic Conductor boundary conditions are not yet available as assembly Pair boundary conditions.

A new set of slit-based, discontinuous boundary conditions, which does not require assemblies is introduced in version 4. In most models, this can replace the assembly pair boundary condition.