modelStrayLoad

Model of stray load losses dependent on current and speed

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to 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

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.

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.

See also

StrayLoad parameters

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

Parameters

TypeNameDefaultDescription
Machines.Losses.StrayLoadParametersstrayLoadParametersStray load loss parameters
BooleanuseHeatPort (from PartialElementaryConditionalHeatPortWithoutT)false= true, if heatPort is enabled

Connectors

TypeNameDefaultDescription
PositivePinp (from TwoPin)Positive electrical pin
NegativePinn (from TwoPin)Negative electrical pin
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.Voltagev (from TwoPin)Voltage drop of the two pins (= p.v - n.v)
SI.Currenti (from OnePort)Current flowing from pin p to pin n
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)