modelStrayLoad

Model of stray load losses dependent on current and speed

Extends from Modelica.Electrical.QuasiStatic.Polyphase.Interfaces.OnePort (Two plugs, reference connection and declaration of voltage and current), Modelica.Electrical.Machines.Interfaces.FlangeSupport (Shaft and support), Modelica.Thermal.HeatTransfer.Interfaces.PartialElementaryConditionalHeatPortWithoutT (Partial model to include a conditional HeatPort in order to dissipate losses, used for textual modeling, i.e., for elementary models).

Information

Stray load losses are modeled similar to standards EN 60034-2 and IEEE 512, i.e., they are dependent on square of current, but without scaling them to zero at no-load current.

For an estimation of dependency on varying angular velocity see: [Lang1984]

The stray load losses are modeled such way that they do not cause a voltage drop in the electric circuit. Instead, the dissipated losses are considered through an equivalent braking torque at the shaft.

The stray load loss torque is

tau = PRef/wRef * (i/IRef)^2 * (w/wRef)^power_w

where i is the current of the machine and w is the actual angular velocity. The dependency of the stray load torque on the angular velocity is modeled by the exponent power_w.

See also

StrayLoad parameters

If it is desired to neglect stray load losses, set strayLoadParameters.PRef = 0 (this is the default).

Parameters

TypeNameDefaultDescription
Integerm (from OnePort)3Number of phases
Modelica.Electrical.Machines.Losses.StrayLoadParametersstrayLoadParametersStray load loss parameters
BooleanuseHeatPort (from PartialElementaryConditionalHeatPortWithoutT)false= true, if heatPort is enabled

Connectors

TypeNameDefaultDescription
PositivePlugplug_p (from OnePort)Positive quasi-static polyphase plug
NegativePlugplug_n (from OnePort)Negative quasi-static polyphase plug
Modelica.Mechanics.Rotational.Interfaces.Flange_aflange (from FlangeSupport)Shaft end
Modelica.Mechanics.Rotational.Interfaces.Flange_asupport (from FlangeSupport)Housing and support
HeatTransfer.Interfaces.HeatPort_aheatPort (from PartialElementaryConditionalHeatPortWithoutT)Optional port to which dissipated losses are transported in form of heat

Components

TypeNameDefaultDescription
SI.ComplexVoltage[m]v (from OnePort)Complex voltage
SI.Voltage[m]abs_v (from OnePort)Modelica.ComplexMath.abs(v)Magnitude of complex voltage
SI.Angle[m]arg_v (from OnePort)Modelica.ComplexMath.arg(v)Argument of complex voltage
SI.ComplexCurrent[m]i (from OnePort)Complex current
SI.Current[m]abs_i (from OnePort)Modelica.ComplexMath.abs(i)Magnitude of complex current
SI.Angle[m]arg_i (from OnePort)Modelica.ComplexMath.arg(i)Argument of complex current
SI.ActivePower[m]P (from OnePort){Modelica.ComplexMath.real(v[k]*Modelica.ComplexMath.conj(i[k])) for k in 1:m}Active power
SI.ActivePowerP_total (from OnePort)sum(P)Total active power
SI.ReactivePower[m]Q (from OnePort){Modelica.ComplexMath.imag(v[k]*Modelica.ComplexMath.conj(i[k])) for k in 1:m}Reactive power
SI.ReactivePowerQ_total (from OnePort)sum(Q)Total reactive power
SI.ApparentPower[m]S (from OnePort){Modelica.ComplexMath.abs(v[k]*Modelica.ComplexMath.conj(i[k])) for k in 1:m}Magnitude of complex apparent power
SI.ApparentPowerS_total (from OnePort)sqrt(P_total^2 + Q_total^2)Magnitude of total complex apparent power
Real[m]pf (from OnePort){cos(Modelica.ComplexMath.arg(Complex(P[k], Q[k]))) for k in 1:m}Power factor
SI.AngularVelocityomega (from OnePort)Angular velocity of reference frame
SI.Anglephi (from FlangeSupport)Angle between shaft and support
SI.Torquetau (from FlangeSupport)Torque
SI.AngularVelocityw (from FlangeSupport)Relative angular velocity of flange and support
SI.PowerlossPower (from PartialElementaryConditionalHeatPortWithoutT)Loss power leaving component via heatPort (> 0, if heat is flowing out of component)
SI.CurrentiRMSquasiRMS(i)