Example11 AC Characteristics of Helical Coil

General

• AC current flows in helical coil.
   

• The coil’s inductance and impedance, and the vectors of the current density are also solved.
   

• Unless specified in the list below, the default conditions will be applied.
   

Analysis Space

Analysis Conditions

The frequency of the current is set to 50[kHz].

Set the Mesh Tab as follows.

Model

A helical solid body Coil (coil) is defined.

Its inflow/outflow faces are extended to the outside of the ambient air. They contact the electric wall of outer boundary condition.

In the magnetic field harmonic analysis, inflow/outflow faces must be outside of the ambient air. (for the purpose of calculation with FEM)

In this Exercise, ambient air is set to be created automatically. Therefore, the inflow/outflow faces are extended to the outside of ambient air.

Body Attributes and Materials

* Available from the Material DB

Body attribute is set up as follows to apply current to the coil.

Boundary Conditions

No setting.

Results

To see the results of inductance and impedance calculation, go to the [Results] tab

 click [Table] .

The inductance of the coil is output as follows.

The impedance is as follows.

The vectors of the magnetic field are shown below.

The vectors of the current density are shown below.

Unlike the static analysis, the current is distributed inside the coil and highly concentrated near the surface.