Current Tab

Setting Item

Notes

Waveform

Sets the type of waveform.

Constant:

Selectable for the constant current.

AC (cos wave):

Selectable for the AC.

Available in the harmonic analysis and the transient analysis.

Current [A] will be as follows.

Amplitude *cos(2πf*t+θπ/180)

User to define:

Defines any waveform for the current.

Available only in the transient analysis.

Sets the current for each time in the [Time-Current] table.

If the current values of the 1st and last points of the data are the same, the set data is treated as one cycle and repeated.

If it is not repeated, fill in the table through the final timestep.

External Circuit Coupling:

Enables coupled analysis with an external circuit.

Selectable only in the transient analysis.

Coil Name on the Circuit:

Sets the names of FEM elements on the external circuit for coupling.
If one body attribute is set on the multiple bodies, the bodies are connected serially in the circuit.

If the [Coil Name on the Circuit] is selected for the different body attributes, they will be connected in series in the circuit.

Value

Current:

Sets the value of the current.

Frequency:

Sets the frequency of the current.

This can be used in the harmonic analysis and the transient analysis.

Phase:

If the magnitude is I and the phase is θ, the current can be represented by:

Iz = I * exp(jθ), where j is the imaginary unit.

This can be used in the harmonic analysis and the transient analysis.

If the current values of the 1st and last points are the same in the user-defined waveform,
assuming the time at the end of the waveform is one period, the phase of waveform is shifted by converting in the range of 0deg and 360 deg.

Turns:

Sets the number of turns of the coil winding.

Depending on the analysis type, the settings will vary as below.

Transient Analysis
Sets the number of element wires across the section of coil for each body.
Be ware that this setting is not for each body attribute.

For example, if the same body attribute name is given to two bodies and the turns are 10, the number of element wires is 10 each totaling 20.

Static Analysis and Harmonic Analysis
Sets the number of element wires across the section of coil for each body attribute.

For example, if the same body attribute name is given to two bodies of the same area and the turns are 10, the number of element wires for each body is 5 totaling 10.

(The element wires are set to each body so as to make the current density equal between the bodies.)

• When the turns are set, the current will be processed as "current value x turns" for the analysis.
  The model with specified turns (bulk coil) will be effective for the coil with high number of turns (100s, 1000s)
  

• If you want to take into account the effect of induced current such as current bias of each coil,
  do not select turns in the harmonic analysis. Create the spiral shape of coil as in Example 11.
  

• If the analysis is coupled with the external circuit, the input value is same regardless of ON or OFF of conversion. The value to input here is the number of wires of each body.
  

• If the body is for the electromotive force calculation, the number of turns set here will be taken into account at the electromotive force calculation.
   

Direction

Sets the direction of the current.

The setting is different depending on the analysis dimension.

3D analysis

Loop Coil/Magnetic Field Direction:

Selectable for the loop coil (closed coil).

Determines the direction by specifying the magnetic field vector created by the loop coil current.

Specify Inflow Face :

Determines the current direction if the coil has end faces (not closed coil).

Selectable only for rotating machinery in the magnetic transient analysis

Click and select the inflow face in the modeling window.

Specify Inflow/Outflow Faces

Determines the current direction if the coil has end faces (not closed coil).

Click and select the inflow and outflow faces in the modeling window.

Specify Inflow/Outflow Faces (In the Air Box):

Selectable if the coil has end faces (not closed coil), and inflow/outflow faces exist in the analysis domain.

Determines the current direction.

Available only in the static analysis. (Analysis can be performed with inflow/outflow faces in the analysis domain)

• [Variance of Results Depending on the Types to Specify Current Direction]

Specify Boundary Conditions:

Determines the direction by setting the port boundary condition on the inflow/outflow faces.

Selectable only in the following cases.

• When the analysis failed for a loop coil with [Loop Coil/Magnetic Field Direction].
  Refer to [How to Define Loop Coil with Boundary Condition] for details.

• When the analysis failed for normal coil with [Specify Inflow/Outflow Faces].

• Compatibility with versions up to 2015
  This is only method available for up to 2015 versions.

2D analysis

+Y Direction:

Sets the current in the +Y direction.

- Y Direction:

Sets the current in the -Y direction.

Distribute the current uniformly

If selected, the current distribution going through the coil will be uniform.

Otherwise, the current density towards the coil center will be higher.

This can be used for the static analysis and the harmonic analysis.

In the case of the lumped coil body representing a multi-turn coil,

the current density tends to be higher towards the coil center.

This is due to the lumped structure,

whereas the actual coil is wound concentrically and

the current going through it is supposed to be uniform. In such a case, select this function.

• It can be used only when the cross sectional area of the coil is constant to the coil length.

• It makes the given (forced) current uniform.
  The induced current will not be uniform.

• Selectable for the 3D analysis only.
  Automatically selected for the 2D analysis and axisymmetric analysis.
  

Induced Current

Available in the harmonic analysis and the transient analysis.

Yes:

Induced current (Eddy current) on the conductor is calculated.

No:

Induced current (Eddy current) on the conductor is not calculated.

• Set No if the coil has turns greater than 1.
  The induced current cannot be calculated correctly even if Yes is selected.
   

Circuitry of Induced Current

Available in the 2D harmonic and the 2D transient analyses. (Not for axisymmetric analysis)

Open :

The circuit will be open if the end of the coil is cut.

The sum of the induced current through the cross section of the conductor will be nil.

• The circuit is required to be open for the forced current.
  

• If there are multiple bodies with an identical body attribute in the transient analysis, the sum of induced current on the cross sections of all bodies will be 0.
  If you want the sum for each body to be 0, assign different body attributes to them.

Short :

Selectable if the circuit is not cut at the end (closed circuit conductor).

The sum of the induced current through the cross section of the conductor is indefinite.

• It is fixed as follows for the axisymmetric analysis.
  Conductor the current flows through: Open
  Conductor the current does not flow through: Short
  

Specify the AC value in the superimposed DC analysis

Specifies the AC value to analyze the superimposed DC characteristic in the harmonic analysis.

See [Superimposed DC Characteristic Analysis] for more information.

• If it is selected
  Superimposed DC value and AC value can be set separately.
  Various losses by AC are output.
  

• If it is deselected
  Only superimposed DC value can be set at [Current(Amplitude)].
  Calculation is done assuming the AC value is minute. Losses or magnetic distributions are not output.
  

• Even if this setting is selected, the superimposed DC analysis is not performed if [with minor-loop] is deselected on the [Permeability] tab for the material setting.
  

Form a loop coil

by connecting

adjoined coils

Applied when the 3D analysis failed for a loop coil with [Loop Coil/Magnetic Field Direction].

Refer to [How to Define Loop Coil with Boundary Condition] for details.

Available only for the static analysis and harmonic analysis.

• Before selecting this function, enter the number of turns
  if the electromotive force is going to be calculated.