Modelica.Electrical.Machines.Losses.InductionMachines

Loss models for induction machines

Information


This package contains loss models used for induction machine models.

Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).

Package Content

NameDescription
Modelica.Electrical.Machines.Losses.InductionMachines.Brush Brush Model considering voltage drop of carbon brushes
Modelica.Electrical.Machines.Losses.InductionMachines.StrayLoad StrayLoad Model of stray load losses dependent on current and speed
Modelica.Electrical.Machines.Losses.InductionMachines.PermanentMagnetLosses PermanentMagnetLosses Model of permanent magnet losses dependent on current and speed
Modelica.Electrical.Machines.Losses.InductionMachines.Core Core Model of core losses

Modelica.Electrical.Machines.Losses.InductionMachines.Brush Modelica.Electrical.Machines.Losses.InductionMachines.Brush

Model considering voltage drop of carbon brushes

Information


Model of voltage drop and losses of carbon brushes. This three-phase model uses three DC Brush loss models.

Extends from Modelica.Electrical.MultiPhase.Interfaces.TwoPlug (Component with one m-phase electric port), Modelica.Thermal.HeatTransfer.Interfaces.PartialConditionalHeatPort (Partial model to include a conditional HeatPort in order to dissipate losses, used for graphical modeling, i.e., for building models by drag-and-drop).

Parameters

NameDescription
mNumber of phases
brushParametersBrush loss parameters
useHeatPort=true, if HeatPort is enabled
TFixed device temperature if useHeatPort = false [K]

Connectors

NameDescription
plug_p 
plug_n 
heatPortOptional port to which dissipated losses are transported in form of heat

Modelica.Electrical.Machines.Losses.InductionMachines.StrayLoad Modelica.Electrical.Machines.Losses.InductionMachines.StrayLoad

Model of stray load losses dependent on current and speed

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:
W. Lang, Über die Bemessung verlustarmer Asynchronmotoren mit Käfigläufer für Pulsumrichterspeisung, Doctoral Thesis, Technical University of Vienna, 1984.

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).

Extends from Modelica.Electrical.MultiPhase.Interfaces.OnePort (Component with two electrical plugs and currents from plug_p to plug_n), 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).

Parameters

NameDescription
mNumber of phases
strayLoadParametersStray load loss parameters
useHeatPort=true, if heatPort is enabled

Connectors

NameDescription
plug_p 
plug_n 
flangeShaft end
supportHousing and support
heatPortOptional port to which dissipated losses are transported in form of heat

Modelica.Electrical.Machines.Losses.InductionMachines.PermanentMagnetLosses Modelica.Electrical.Machines.Losses.InductionMachines.PermanentMagnetLosses

Model of permanent magnet losses dependent on current and speed

Information


Permanent magnet losses are modeled dependent on current and speed.

The permanent magnet 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 permanent magnet loss torque is

  tau = PRef/wRef * (c + (1 - c) * (i/IRef)^power_I) * (w/wRef)^power_w

where i is the current of the machine and w is the actual angular velocity. The parameter c designates the part of the permanent magnet losses that are present even at current = 0, i.e. independent of current. The dependency of the permanent magnet loss torque on the stator current is modeled by the exponent power_I. The dependency of the permanent magnet loss torque on the angular velocity is modeled by the exponent power_w.

See also

Permanent magnet loss parameters

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

Extends from 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).

Parameters

NameDescription
mNumber of phases
permanentMagnetLossParametersPermanent magnet loss parameters
useHeatPort=true, if heatPort is enabled

Connectors

NameDescription
flangeShaft end
supportHousing and support
heatPortOptional port to which dissipated losses are transported in form of heat

Modelica.Electrical.Machines.Losses.InductionMachines.Core Modelica.Electrical.Machines.Losses.InductionMachines.Core

Model of core losses

Information


Core losses can be separated into eddy current and hysteresis losses. The total core losses can thus be expressed as

  P = PRef * (ratioHysteresis * (wRef / w) + 1 - ratioHysteresis) * (V / VRef)^2

where w is the actual angular remagnetization velocity and V is the actual voltage. The term ratioHysteresis is the ratio of the hysteresis losses with respect to the total core losses for the reference voltage and frequency.

In the current implementation hysteresis losses are not considered since complex numbers are not provided in Modelica. Therefore, implicitly ratioHysteresis = 0 is set. For the voltage and frequency range with respect to Fig. 1, the dependency of total core losses on the parameter ratioHysteresis is depicted in Fig. 2. The current implementation has thus the drawback over a model that considers ratioHysteresis > 0:

corelossesVw.png
Fig. 1: Voltage versus angular velocity
corelossesPcw.png
Fig. 2: Core losses versus angular velocity with parameter ratioHysteresis

Note

In the current implementation it is assumed that ratioHysteresis = 0. This parameter cannot be changed due to compatibility reasons.

See also

Core loss parameters

Extends from 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).

Parameters

NameDescription
coreParameters 
turnsRatioEffective number of stator turns / effective number of rotor turns (if used as rotor core)
useHeatPort=true, if heatPort is enabled
Losses
wRemagnetization angular velocity [rad/s]

Connectors

NameDescription
heatPortOptional port to which dissipated losses are transported in form of heat
spacePhasor 

Automatically generated Mon Sep 23 17:20:31 2013.