How to set-up the iron loss model?

To calculate iron losses you have four possibilities:

  • use some interpolation of experimental data
  • use the built-in Bertotti models of MANATEE
  • use the magnetic losses provided by lamination sheet suppliers (does not include the effect of rotating flux)
  • define your own iron loss model

The main outputs of the iron loss calculation include

  • Output.Electrical.PILys0: stator yoke fundamental iron losses [W]
  • Output.Electrical.PILts0: stator teeth fundamental iron losses [W]
  • Output.Electrical.PILyr0: rotor yoke fundamental iron losses [W]
  • Output.Electrical.PILtr0: rotor teeth fundamental iron losses [W]

Use of experimental iron loss data

This mode is activated in the simulation project with

Input.Simu.type_ironloss = 1;

Loss data is stored in the machine data file as cells. You can have a look at the default_machine.m script as an example.

Input.Magnetics.PILExp{1} contains the vector of frequencies at which iron losses are measured, and Input.Magnetics.PILExp{2} to Input.Magnetics.PILExp{nf+1} contains the vector of experimental losses in W (size [1,nv]) as a function of line to line RMS voltage. The cell Input.Magnetics.UExp{1} to Input.Magnetics.UExp{nf} contains the vectors of line to line RMS voltage (size [1,nv]) at each frequency.

Use of user-defined Bertotti iron loss models

This mode is activated in the simulation project with

Input.Simu.type_ironloss = 2;

MANATEE provides a Bertotti model based on fundamental values of flux densities in the different parts of the machine (rotor and stator teeth and yoke).

The general formula for stator teeth iron losses is given by

PILts = KilHs*(Kst1*Mteeth1/Mst1)*freq0.*BT1av.^alphaBH+KilFs*(Wslam^2*Kst1*Mteeth1/Mst1/6)*(pi*freq0.*BT1av).^alphaBF+KilEs*(Kst1*Mteeth1/Mst1)*(freq0.*BT1av).^alphaBE;

All Bertotti coefficients can be tuned in the machine data file using

Input.Magnetics.KilHs=185.7888;              % Bertotti iron loss model hysteresis loss coefficient (stator) [Ws/T^2/m^3]
Input.Magnetics.KilHr=185.7888;              % Bertotti iron loss model hysteresis loss coefficient (rotor) [Ws/T^2/m^3]
Input.Magnetics.KilFs=2380952.381;        % Bertotti iron loss model eddy current loss coefficient - corresponds to the material electrical conductivity [S/m]
Input.Magnetics.KilFr=2380952.381;        % Bertotti iron loss model eddy current loss coefficient - corresponds to the material electrical conductivity [S/m]
Input.Magnetics.KilEs=1.4869;             % Bertotti iron loss model excess loss coefficient on stator side [W(T/s)^AlphaBE/m^3]
Input.Magnetics.KilEr=1.4869;             % Bertotti iron loss model excess loss coefficient on rotor side [W(T/s)^AlphaBE/m^3]
Input.Magnetics.alphaBH=2;              % Bertotti B power coefficient for hysteresis losses (default: 2)
Input.Magnetics.alphaBF=2;              % Bertotti dBdt power coefficient for Foucault losses (default: 2)
Input.Magnetics.alphaBE=1.5;            % Bertotti dBdt power coefficient for excess losses (default: 1.5)

A more detailed model, based on the harmonic decomposition of the flux density waveform calculated in teeth and yoke, is under development.

Use of Bertotti iron loss models based on magnetic sheet supplier data

This mode is activated in the simulation project with

Input.Simu.type_ironloss = 3;

The model is exactly the same as the previous one but the Bertotti coefficient are automatically fit with the lamination magnetic loss data.

Use of magnetic sheet supplier data

This mode is activated in the simulation project with

Input.Simu.type_ironloss = 4;

The magnetic losses should be defined in W/m^3 as a .txt file in MaterialData folder named "lamination_nameW.txt" (for instance "M400-50AW.txt" for the material named "M400-50A" in the material database). The first line should contain working frequencies in Hz, and the columns should contain alternatively the flux density value and the power loss density. The lamination material weights are calculated in MANATEE and simply multiplied by the loss density at the given frequency.

Definition of your own iron loss models

You can use MANATEE post processing scripts to define your own iron loss models. You may have to access to the following outputs:

  • Output.Magnetics.BT1av0: average stator tooth flux density [T]
  • Output.Magnetics.BT2av0: average rotor tooth flux density [T]
  • Output.Magnetics.BY1av0: average stator yoke flux density [T]
  • Output.Magnetics.BY2av0: average rotor yoke flux density [T]
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