Home / Examples / Magnetic Analysis (Luvens, Transient Analysis) / Example 8: Iron Loss of Coil Wound on Core (Sine Wave Analysis with B-H Curve Taken into Account)

Example 8: Iron Loss of Coil Wound on Core (Sine Wave Analysis with B-H Curve Taken into Account)

General

• A coil is wound on a core. The iron loss is analyzed.
  

• Permeability is set with B-H curve table.
  The effect of magnetic saturation is taken into account in this example whereas it is not taken into account in the [Example 29: Heating due to the Iron Loss] of magnetic field harmonic analysis.
   

• 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.
   

• See Example 2 regarding the calculation of heating due to the iron loss.
   

• Obtain this session's project file. (Right-click and choose 'Save link as')




• Results will vary depending on Femtet version and the PC environment.

 

Analysis Space

Item	Settings
Analysis Space	3D
Model Unit	mm

 

Analysis Conditions

Item	Settings
Solver	Magnetic Analysis [Luvens]
Analysis Type	Transient Analysis
Options	None

 

The transient analysis tab is set up as follows.

An analysis is performed for one cycle of a 50 kHz AC input.

To reproduce its waveform well, the timestep is set by dividing the periodic time of 50 kHz by the default value of 12.

Tab	Setting Item	Settings
Transient Analysis	Timestep	Automatic
	Timestep Setting	Number of Cycles 1

 

Graphical Objects

A coil is wound on a core.

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

The loss characteristics are defined in the iron loss table.

 

Body Attributes and Materials

Body Number/Type	Body Attribute Name	Material Name
5/Solid	Coil	008_Cu *
6/Solid	Core	Core

(*) Available from the material DB

 

The material properties of the core are set up as follows.

The permeability is defined with B-H curve table.

The loss characteristics are defined with the iron loss table.

Material Name	Tab	Settings
Core	Permeability	Magnetization Characteristic Type: Select [B-H Curve]    B-H Curve Table Magnetic Field [A/m] Magnetic Flux Density [T] 0 0 58 0.219 90 0.33 180 0.59 380 0.69 1100 0.75 2000 0.78 3000 0.8 11000 0.9 20000 0.95
	Electric Conductivity	Conductivity Type: Conductor Conductivity: 0.1 [S/m]
	Iron Loss	Iron Loss Calculation Type: Iron Loss Table    Frequency: 5x104 [Hz] [Magnetic Flux Density-Loss Density] Table * Magnetic Flux Density [T] Loss Density [W/m^3] 50x10-3 5x103 500x10-3 500x103   * This is not the actual material's property.

Press the Graph button. The following graph will show up.

 

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

Body Attribute Name	Tab	Settings
Coil	Current	Waveform: AC Current: 0.1 [A] Frequency: 50x103 [Hz] Turns: 100 [Turns] Direction: Loop Coil/Magnetic Field Direction Direction Vector of Magnetic Field: X=0, Y=0, Z=1

Boundary Condition

No setting.

Results

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

 

 

 and click [Show Numerical Summary Table] .

 

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

 

 

The core's iron loss is approximately 0.5 W.

The joule loss and the hysteresis loss of the core are not given because the the material property is defined on the iron loss table.

The loss characteristics are defined in the iron loss table. Only iron loss is obtained.

If it is defined by the iron loss experimental formula, the joule loss and the hysteresis loss will be output as well.

 

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

• See also [Iron Loss Calculation].

 

The vectors of the magnetic field are shown below.

 

The vectors of the magnetic flux density are shown below.

The flux density is looping through the core.

 

The iron loss density is shown below.