Coil conductor with losses regions

Principle

It is possible to express the local losses in strand conductors by using equivalent properties (permeability, conductivity).

This technique is very useful to reduce the mesh size and to solve more quickly complex problems.

Tab: General

In the General tab, user enters the data about the elementary strands organization in a “ physical point of view”:

  • Material
  • Number of strands in parallel
  • Associated component

The vocabulary used is presented in the following table:

Definition Example
The coil conductor (or winding) is constituted by turns Coil conductor = 20 turns
Each turn is constituted by elementary strands in parallel Turn =4 elementary strands in //
The elementary strand is the “real wire”.

Elementary strand = …

(80 elementary strands)

Tab: Strand definition

In the Strand definition tab, user enters the data about the elementary strands organization in “geometrical point of view”:

  • Choosing a section type (shape)
  • Geometrical definition (section dimensions, gap between strands)
  • Disposition, strands orientation in the section plane*.

The geometrical elementary strands organization is done in the section plane*. The specific information for 2D, 3D and rectangular or circular sections are explained in the following parts.

Note: * The section plane is the plane where the strands geometrical description is done. The section plane is a plane perpendicular to the current.

Process limitations

  • It is necessary to have enough strands in the two x and y plane directions: the minimum is 8 to 10 strands in each direction.
  • The ambient field should have a very little variation on several strands
  • The strands arrangement can be non uniform but it offers less precision in the results. In this case, it is necessary to determine a mean gap between strands

Reading advices

For complementary information, please refer to the following documents:

« Propriétés macroscopiques équivalentes pour représenter les pertes dans les bobines conductrices »,

G. Meunier – A.T. Phung – O. Chadebec – X. Margueron – J. Keradec, RIGE 11, 6 (2008) p. 675-694.

“Homogenization for Periodical Electromagnetic Structure: Which Formulation?”

G. Meunier, V. Charmoille, C. Guérin, P. Labie, and Y. Maréchal.

IEEE TRANSACTIONS ON MAGNETICS, Vol. 46, No. 8, August 2010