Example2 Heating due to the Iron Loss (AC Analysis with B-H Curve Taken into Account)

General

A coil is wound on a core. The heating due to the iron loss is analyzed.
Permeability is set with B-H curve table.
The effect of magnetic saturation is taken into account in this exercise whereas it cannot be taken into account in the [Exercise 3: Heating due to the Iron Loss] of magnetic field harmonic analysis.
The vectors of the magnetic field, the loss in the core, and the temperature distribution by the heating 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 Field Analysis [Luvens] Thermal Analysis [Watt]
Analysis Type	Magnetic field analysis: Transient Analysis Thermal analysis: Steady-State Analysis
Options	None

The Transient Analysis tab is set up as follows.

50KHz AC is input. To reproduce its waveform well, the time step is set by dividing the periodic time of 50KHz by 12.

Tab

Setting Item

Setting

Transient Analysis

Time step

Automatic

Table

Number	Calculation steps	Output steps	Time step [s]
1	12	1	1.0/(12*50e3)

Graphical Objects

A coil is wound on a core.

The bodies of a core (Core) and a loop coil (Coil) are defined.

The automatically created ambient air is applicable only in the magnetic field analysis, not in the thermal analysis.

Body Attributes and Materials

Body Number/Type	Body Attribute Name	Material Name
5/Solid	Coil2	008_Cu *
7/Solid	Coil1	008_Cu *
6/Solid	Core	Core

(*) Available from the Material DB

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

Body Attribute Name

Tab

Setting

Coil

Current

Waveform: AC

Current: 0.1[A]

Turns: 100[Turns]

Induced current: None

Direction: Loop Coil/Magnetic Field Direction

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

The material properties of the core are set up as follows. The loss is defined in the iron loss table.

Material Name

Tab

Setting

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]

Thermal Conductivity

Thermal Conductivity: 10[W/m/deg]

Iron Loss

Iron Loss Calculation Type: Iron loss table

Frequency: 5×104[Hz]

[Magnetic flux density-Loss density] Table *

Magnetic Flux Density [T]	Joule Loss Density [W/m^3]
50×10-3	5×10^3
500×10-3	500×10^3

* This is not the actual material’s property.

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

Boundary Condition

“Natural convection (automatic calculation)” is set on the outer boundary condition (surrounding the coil and core in the case of the thermal analysis).

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Setting

Outer Boundary Condition *

Thermal

Heat Transfer/Ambient Radiation

Natural convection (automatic calculation)

Room temperature: 25[deg]

To set Outer Boundary Condition, go to the [Model] tab