modelStrayLoad
Extends from Modelica.Electrical.Polyphase.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).
Information
Stray load losses are modeled similar to standards EN 60034-2 and IEEE 112, 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
If it is desired to neglect stray load losses, set strayLoadParameters.PRef = 0 (this is the default).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | m (from TwoPlug) | 3 | Number of phases |
| Machines.Losses.StrayLoadParameters | strayLoadParameters | Stray load loss parameters | |
| Boolean | useHeatPort (from PartialElementaryConditionalHeatPortWithoutT) | false | = true, if heatPort is enabled |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| PositivePlug | plug_p (from TwoPlug) | Positive polyphase electrical plug with m pins | |
| NegativePlug | plug_n (from TwoPlug) | Negative polyphase electrical plug with m pins | |
| Modelica.Mechanics.Rotational.Interfaces.Flange_a | flange (from FlangeSupport) | Shaft end | |
| Modelica.Mechanics.Rotational.Interfaces.Flange_a | support (from FlangeSupport) | Housing and support | |
| HeatTransfer.Interfaces.HeatPort_a | heatPort (from PartialElementaryConditionalHeatPortWithoutT) | Optional port to which dissipated losses are transported in form of heat |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Voltage[m] | v (from TwoPlug) | Voltage drops of the two polyphase plugs | |
| SI.Current[m] | i (from TwoPlug) | Currents flowing into positive polyphase plugs | |
| SI.Angle | phi (from FlangeSupport) | Angle between shaft and support | |
| SI.Torque | tau (from FlangeSupport) | Torque | |
| SI.AngularVelocity | w (from FlangeSupport) | Relative angular velocity of flange and support | |
| SI.Power | lossPower (from PartialElementaryConditionalHeatPortWithoutT) | Loss power leaving component via heatPort (> 0, if heat is flowing out of component) | |
| SI.Current | iRMS | quasiRMS(i) |