Variable inductor

Inductance set by the input signal.

  • signal
  • electrical
  • Modelica Standard Library
  • 3 ports
  • 1 parameter
BlockVariable inductorKindvariableInductorLibraryElectrical

Description

An inductor whose inductance is set by an input signal. The flux linkage is inductance times current, so changing the inductance at fixed flux changes the current.

Example

Variable parts A resistor, an inductor, and a capacitor whose values follow signals, and a potentiometer.

R = 10 + 5 sin 2πtDC 10 VVariable resistori RGround RL = 2 + sin(πt/2)DC 1 VVariable inductori LGround LC₀ = 1 mF+1 mF at 0.5 sCDC 1 mAVariable capacitorv CGround CWiper positionDC 10 V (pot)PotentiometerWiper voltageGround P
In Gradara, select a Variable inductor 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 voltageVoltage sensorCurrent sensorSumConstantStepGroundRampSine waveVariable resistorVariable capacitorPotentiometerDC current

Ports

Inputs 1

  • Lsignal · H

    Inductance, in henries. Must stay 0 or more.

Conserving terminals 2

  • +pelectrical

    Positive pin. Current into p is counted as positive.

  • −nelectrical

    Negative pin.

Parameters

  • Minimum inductanceLmin1e-12 H

    ≥ 0

    Lower bound on the inductance used in the equations, in henries. Keeps the model solvable when the input reaches 0.

Equations

Modelica
v = p.v − n.v, i = p.i, p.i + n.i = 0
Psi = max(L, Lmin) · i
v = dPsi/dt

Implementation

Modelica Standard Library 4.1.0Modelica.Electrical.Analog.Basic.VariableInductor
MSL documentation

Assumptions and limitations

  • The simulation stops with an error if the input goes negative.
  • The initial current is not fixed by the block.

See also

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