Variable reluctance

Reluctance set by the input signal.

  • signal
  • magnetic
  • Modelica Standard Library
  • 3 ports
BlockVariable reluctanceKindvariableReluctanceLibraryMagnetic

Description

A reluctance set at each instant by an input signal, for example a gap that opens and closes. The reluctance does not need to be constant or positive, but a zero or negative value is not physical.

Example

Magnetic circuits A 100-turn winding drives flux through an air gap and a core, next to magnetic sources and a variable reluctance.

1 VGroundR 1 ΩWinding 100 turnsCore fluxAir gapCoreMagnetic groundGap mmfmmf 100 AGround (mmf)R_m signalVariable reluctanceFlux (variable)Ground (variable)50 ASignal mmfGround (signal)Permeance 1 µWb/AFlux (permeance)Ground (permeance)Flux 1 mWbGround (flux)Reluctance 10⁶mmf acrossGround (reluctance)
In Gradara, select a Variable reluctance block and press F1, then choose Open example. It opens as a new model in My models, ready to run.

Also in this example:DC voltageStepGroundSine waveResistorReluctancePermeanceWindingMagnetic groundMMF sourceControlled MMF sourceFlux sourceFlux sensorMMF sensor

Ports

Inputs 1

  • RmR_msignal · 1/H

    Reluctance, in A/Wb.

Conserving terminals 2

  • +port_pmagnetic

    Positive magnetic port. Flux entering port_p is counted as positive Φ.

  • −port_nmagnetic

    Negative magnetic port.

Equations

Modelica
V_m = port_p.V_m − port_n.V_m
V_m = R_m · Φ, with Φ = port_p.Φ

Implementation

Modelica Standard Library 4.1.0Modelica.Magnetic.FluxTubes.Basic.VariableReluctance
MSL documentation

Assumptions and limitations

  • No force on a moving part: changing the reluctance does not produce a mechanical reaction.

See also

Select a block in Gradara and press F1 to open its page offline.