Example12 Iron Loss by Input Current with Arbitrary Waveform (Triangle Wave)

General

  • The iron loss is calculated when the arbitrary-waveform current is input to the coil wound on a core. In this example, the waveform is triangle wave.
    A square wave can be analyzed in the same way.

  • To calculate the iron loss with the arbitrary waveform, [Frequency Analysis 8FFT)] is used as a calculation method.
     

  • The core loss, the vectors of the magnetic field and the magnetic flux density are solved.
     

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

 

Analysis Space

Item

Setting

Analysis Space

3D

Model Unit

mm

 

Analysis Conditions

Item

Setting

Solver

Magnetic Analysis [Luvens]

Analysis Type

Transient Analysis

Options

None

The Transient Analysis tab is set up as follows.

The input is 50 [kHz]. In order to reproduce the triangle waveform well, and also in order to take into account the frequency component high enough to calculate the iron loss by FFT,
the timestep is one period of 50 [kHz] divided by 24.

Tab

Setting Item

Setting

Transient Analysis

Timestep

Automatic

Table

Number

Calculation steps

Output steps

Timestep [s]

1

24

1

1.0/(24*50e3)

 

 

 

Model

A coil is wound on a core.

The model is defined by the core (Core) and the loop coil (Coil) are defined.

 

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

5/Solid

Coil

008_Cu *

6/Solid

Core

MB3_23deg_JFE Ferrite *

* Available from the material DB

 

The material properties are set up as follows:

[MB3_23deg_JFE Ferrite] is used for the core.

The values for the B-H curve and the iron loss table are taken from the database. The iron loss calculation type is manually changed to [Frequency Analysis (FFT)] from [Amplitude].
The iron loss calculation by the iron loss table is executed by comparing the the amplitude of the frequency and the magnetic flux density with the table.
if the sine wave is not used, the harmonic component of the iron loss cannot be taken into account unless the frequency analysis (FFT) is performed.

See Permeability tab for detail.

Material Name

Tab

Setting

MB3_23deg_JFE Ferrite

Iron Loss

Calculation Method: Frequency Analysis (FFT)

Fundamental frequency: Specify frequency/50[kHz)

 

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

The current is a triangle wave with frequency of 50kHz and amplitude of 1A.

Body Attribute Name

Tab

Setting

Coil

Current

Waveform: Arbitrary waveform

 

[Time-Current] Table

Time [s]

Current [A]

0

0

1/4/50e3

1.0

2/4/50e3

0

3/4/50e3

-1.0

4/4/50e3

0

 

Current: 0.1[A]

Frequency: 50×103[Hz]

Turns: 100[Turns]

Direction: Loop Coil/Magnetic Field Direction

Direction Vector of Magnetic Field: X=0, Y=0, Z=1

Enter the values covering one phase in the [Time-Current] table and the current will repeat automatically.

By pressing the graph button of the [Time-Current] table, the repetition can be seen as shown below.

Boundary Conditions

No setting.

Results

To see the iron loss, go to the [Results] tab

 

 

 and click [Table] .

 

The results are shown on the [Loss [W] (referring to value over 1 period from the final step)] tab as below.

 

Each frequency component is output on the [Frequency component (FFT) of iron loss [W]] tab.

Below is the results plotted in a graph.

AS the input current is a triangle wave, harmonic components can be seen.

 

  • See [Loss Calculation in the Magnetic Analysis] for details of the loss.

  • See also [Iron loss calculation].

 

The vectors of the magnetic field at timestep 1 are shown below.

 

The vectors of the magnetic flux density at timestep 1 are shown below.

 

 

The iron loss density is shown below.