Iron Loss Tab

Setting Items

Notes

Iron Loss Calculation Type

Select one of the following:

[Joule Loss Only (calculation from current distribution)], [Iron loss empiric formula], [Iron loss table]

The details of setup for each type are explained as follow.

Calculation method with reference to magnetic flux density

To obtain the total iron loss, the iron loss density is calculated for each mesh from the magnetic flux density and the frequency.
How to refer to the magnetic flux density is selected.

It is available for the magnetic transient analysis only.

Amplitude (Variation Width/2)

The maximum and minimum values are obtained from the time series data of the magnetic flux density for each mesh. The amplitude is calculated from (max value - min value)/2.

The fundamental frequency is referred to.

Maximum Value

The maximum values is obtained from the time series data of the magnetic flux density.

The fundamental frequency is referred to.

Frequency Analysis (FFT)

The Fourier transform (FFT) is applied to the series data of the magnetic flux density for each mesh to decompose into frequency components.
The iron loss is calculated with each frequency component.

The components of the frequencies higher than the fundamental frequency are handled.

The higher frequency components can be calculated in proportion to the number of calculation points.

Select this option if the waveform of the input current is not sine wave, or if the iron loss of the harmonics needs to be taken into account.

• The fundamental frequency used for the iron loss calculation can be set on the [Magnetic Analysis] tab in the analysis condition setting.

• The iron loss is calculated with the result over 1 period from the last step.
  Periodic time is calculated by [1/fundamental frequency]

[Joule Loss Only (calculation from current distribution]

Only Joule loss is calculated. Hysteresis loss is not taken into account.

Select this for the material with no hysteresis loss taken into account.

[Iron Loss Empiric Formula]

The iron loss is calculated from the formula with the magnetic flux density and the frequency.

Enter the constants in the formula.

Empiric Formula

Wh: Hysteresis loss density [W/m^3]

We: Joule loss density [W/m^3]

B: Magnetic flux density [T]

f: Fundamental frequency [Hz]

Magnetic flux density refers to the maximum value.

Frequency refers to the fundamental frequency.

• See [Iron loss calculation for the details.

If "Calculate Joule loss from current distribution" is selected, only the Joule loss will be

calculated from the current distribution.

• If the constants are unknown, opt for "Calculate Joule loss from current distribution"
  and acquire Kh through experiments while keeping the default values for α and β.

• The default values: α = 1.6, β = 1, γ = 2, and δ = 2.

[Iron Loss Table]

The iron loss is calculated from the table of magnetic flux density and loss density.

The magnetic flux density and the loss density need to be entered for each frequency.

Magnetic flux density refers to the maximum value.

Frequency refers to the fundamental frequency.

• See [Iron loss calculation for the details.

At [Add Table], enter the frequency and click . Set the [Magnetic flux density-Loss density] Table.

At [Edit/Check Table], the contents of the table can be checked, edited and deleted.

Click the [Graph] button. The [Magnetic flux density-Loss density] graph will show up for each frequency.

• Please obtain the data for magnetic flux density and the loss density on the website of the material manufacturer.
  Those data are usually open to public.

• For the frequency in between the entered frequencies, the data will be interpolated.

• For the frequency out of the table range, the data of nearest 2 points will be extended linearly.

• The interpolation and the extrapolation are made on a logarithmic scale for the magnetic flux density, the loss density, and the frequencies.