model PermanentMagnetLosses "Model of permanent magnet losses dependent on current and speed"
import Modelica.Electrical.QuasiStationary.MultiPhase.Functions.quasiRMS;
extends Modelica.Electrical.Machines.Interfaces.FlangeSupport;
parameter Integer m(min = 1) = 3 "Number of phases";
parameter Modelica.Electrical.Machines.Losses.PermanentMagnetLossParameters permanentMagnetLossParameters "Permanent magnet loss parameters";
extends Modelica.Thermal.HeatTransfer.Interfaces.PartialElementaryConditionalHeatPortWithoutT(useHeatPort = false);
input Modelica.SIunits.ComplexCurrent is[m] "Instantaneous stator currents";
Modelica.SIunits.Current iRMS = quasiRMS(is);
equation
if permanentMagnetLossParameters.PRef <= 0 then
tau = 0;
else
tau = -permanentMagnetLossParameters.tauRef * (permanentMagnetLossParameters.c + (1 - permanentMagnetLossParameters.c) * (iRMS / permanentMagnetLossParameters.IRef) ^ permanentMagnetLossParameters.power_I) * sign(w) * (abs(w) / permanentMagnetLossParameters.wRef) ^ permanentMagnetLossParameters.power_w;
end if;
lossPower = -tau * w;
annotation (
defaultComponentName = "magnetLoss",
Icon(graphics = {
Ellipse(
extent = {
{-40, -40},
{40, 40}},
lineColor = {200, 0, 0})}),
Documentation(info = "<html>\n<p>\nPermanent magnet losses are modeled dependent on current and speed.\n</p>\n<p>\nThe permanent magnet losses are modeled such way that they do not cause a voltage drop in the electric circuit.\nInstead, the dissipated losses are considered through an equivalent braking torque at the shaft.\n</p>\n<p>\nThe permanent magnet loss torque is\n</p>\n<pre>\n tau = PRef/wRef * (c + (1 - c) * (i/IRef)^power_I) * (w/wRef)^power_w\n</pre>\n<p>\nwhere <code>i</code> is the current of the machine and <code>w</code> is the actual angular velocity.\nThe parameter <code>c</code> designates the part of the permanent magnet losses that are present even at current = 0, i.e. independent of current.\nThe dependency of the permanent magnet loss torque on the stator current is modeled by the exponent <code>power_I</code>.\nThe dependency of the permanent magnet loss torque on the angular velocity is modeled by the exponent <code>power_w</code>.\n</p>\n<h4>See also</h4>\n<p>\n<a href=\"modelica://Modelica.Electrical.Machines.Losses.PermanentMagnetLossParameters\">Permanent magnet loss parameters</a>\n</p>\n<p>\nIf it is desired to neglect permanent magnet losses, set <code>strayLoadParameters.PRef = 0</code> (this is the default).\n</p>\n</html>"));
end PermanentMagnetLosses;