modelEddyCurrentTorque
Extends from Modelica.Mechanics.Rotational.Interfaces.PartialTorque (Partial model of a torque acting at the flange (accelerates the flange)), Modelica.Thermal.HeatTransfer.Interfaces.PartialElementaryConditionalHeatPort (Partial model to include a conditional HeatPort in order to dissipate losses, used for textual modeling, i.e., for elementary models).
Information
This is a simple model of a rotational eddy current brake. The torque versus speed characteristic is defined by Kloss' equation.
The influence of excitation is either constant (useExcitationInput=false) or given by the optional input excitation (useExcitationInput=true).
Note that maximum torque depends on square of excitation (magnetic field).
Thermal behaviour:
The resistance of the braking disc is influenced by the actual temperature Theatport, which in turn shifts the speed w_nominal at which the (unchanged) maximum torque occurs.
If the heatPort is not used (useHeatPort = false), the operational temperature remains at the given temperature T.
However, the speed w_nominal at which the maximum torque occurs is adapted from reference temperature TRef to the operational temperature.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | useExcitationInput | false | Enable signal input for excitation |
| Real | constantExcitation | 1 | Excitation=1 to reach maximum torque |
| SI.Torque | tau_nominal | Maximum torque (always braking) | |
| SI.AngularVelocity | w_nominal | Nominal speed (leads to maximum torque) at reference temperature | |
| SI.Temperature | TRef | Reference temperature | |
| Modelica.Electrical.Machines.Thermal.LinearTemperatureCoefficient20 | alpha20 | Temperature coefficient of material | |
| Boolean | useSupport (from PartialElementaryOneFlangeAndSupport2) | false | = true, if support flange enabled, otherwise implicitly grounded |
| Boolean | useHeatPort (from PartialElementaryConditionalHeatPort) | false | = true, if heatPort is enabled |
| SI.Temperature | T (from PartialElementaryConditionalHeatPort) | 293.15 | Fixed device temperature if useHeatPort = false |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Flange_b | flange (from PartialElementaryOneFlangeAndSupport2) | Flange of shaft | |
| Support | support (from PartialElementaryOneFlangeAndSupport2) | Support/housing of component | |
| HeatTransfer.Interfaces.HeatPort_a | heatPort (from PartialElementaryConditionalHeatPort) | Optional port to which dissipated losses are transported in form of heat | |
| Blocks.Interfaces.RealInput | excitation | excitationInternal | Excitation |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Angle | phi (from PartialTorque) | Angle of flange with respect to support (= flange.phi - support.phi) | |
| SI.Power | lossPower (from PartialElementaryConditionalHeatPort) | Loss power leaving component via heatPort (> 0, if heat is flowing out of component) | |
| SI.Temperature | TheatPort (from PartialElementaryConditionalHeatPort) | Temperature of heatPort | |
| SI.Torque | tau | Accelerating torque acting at flange (= flange.tau) | |
| SI.AngularVelocity | w | Angular velocity of flange with respect to support (= der(phi)) | |
| Real | w_normalized | Relative speed w/w_nominal |