model Permeability "Determines permeability from flux and magnetic potential difference"
parameter Modelica.SIunits.Area A "Area of cross section penetrated by flux";
parameter Modelica.SIunits.Length l "Length associated with magnetic potential difference";
Modelica.Blocks.Interfaces.RealInput Phi "Magnetic flux"
annotation (Placement(transformation(extent = {
{-140, 40},
{-100, 80}})));
Modelica.Blocks.Interfaces.RealInput V_m "Magnetic potential difference"
annotation (Placement(transformation(extent = {
{-140, -80},
{-100, -40}})));
Modelica.Blocks.Interfaces.RealOutput mu "Absolute permeability"
annotation (Placement(transformation(extent = {
{100, 50},
{120, 70}})));
Modelica.Blocks.Interfaces.RealOutput mur "Relative Permeability"
annotation (Placement(transformation(extent = {
{100, -70},
{120, -50}})));
equation
if noEvent(abs(V_m) < Modelica.Constants.eps) then
mu = 0;
mur = 0;
else
mu = Phi / V_m * l / A;
mur = mu / Modelica.Constants.mue_0;
end if;
annotation (
Diagram(coordinateSystem(preserveAspectRatio = false)),
Icon(
coordinateSystem(preserveAspectRatio = false),
graphics = {
Rectangle(
extent = {
{-100, 100},
{100, -100}},
lineColor = {0, 0, 127},
fillColor = {255, 255, 255},
fillPattern = FillPattern.Solid),
Text(
extent = {
{60, -60},
{-60, 60}},
fillColor = {255, 170, 85},
fillPattern = FillPattern.Solid,
textString = "mu")}),
Documentation(info = "<html>\n<p>This model determines the absolute and relative permeability from two real inputs:</p>\n<ul>\n<li>RMS magnetic potential difference,\n<img src=\"modelica://Modelica/Resources/Images/Magnetic/QuasiStatic/FluxTubes/realV_m.png\" alt=\"V_m\"></li>\n<li>RMS magnetic flux,\n<img src=\"modelica://Modelica/Resources/Images/Magnetic/QuasiStatic/FluxTubes/realPhi.png\" alt=\"Phi\"></li>\n</ul>\n<p>In order to calculate the permeabilities, the area of cross section,\n<img src=\"modelica://Modelica/Resources/Images/Magnetic/QuasiStatic/FluxTubes/A.png\" alt=\"l\">,\nand the geometric length,\n<img src=\"modelica://Modelica/Resources/Images/Magnetic/QuasiStatic/FluxTubes/l.png\" alt=\"l\">,\nof the flux path have to be take into account</p>\n<dl><dd>\n<img src=\"modelica://Modelica/Resources/Images/Magnetic/QuasiStatic/FluxTubes/permeabilities.png\" alt=\"Permeabilities\">\n</dd></dl>\n<p>In case that the magnetic potential difference is close to zero, permeabilities yield:</p>\n<dl><dd>\n<img src=\"modelica://Modelica/Resources/Images/Magnetic/QuasiStatic/FluxTubes/permeabilities-0.png\" alt=\"Permeabilities=0\">\n</dd></dl>\n</html>"));
end Permeability;