Opening switch

Ideal switch that opens while its control input is true.

  • Boolean
  • electrical
  • Modelica Standard Library
  • 3 ports
  • 2 parameters
BlockOpening switchKindopeningSwitchLibrarySemiconductors

Description

An ideal bidirectional switch that is open while control is true and closed while it is false. Use it to disconnect a branch or inject a fault at a set time.

Example

Switches and a breaker An ideal switch, closing and opening switches, a two-way switch, and a breaker that opens an inductive circuit.

10 V Ai ALoad AIdeal switchGate 5 HzGround A10 V Bi BClosing switchClose at 0.1 sLoad BGround B10 V Ci COpening switchOpen at 0.1 sLoad CGround CL 10 mH10 V Di DBreakerTrip at 0.1 sLoad DGround D10 V Ei ETwo-way switchChange over at 0.1 sLoad 10 ΩLoad 20 ΩGround E
In Gradara, select a Opening switch 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 voltageIdeal switchCurrent sensorGroundPulseResistorInductorSwitch (Boolean)Changeover switchBreaker (with arc)Boolean step

Ports

Inputs 1

  • offcontrolBoolean

    Boolean command: true opens the switch.

Conserving terminals 2

  • +pelectrical

    Terminal 1. Current into p is counted as positive.

  • −nelectrical

    Terminal 2.

Parameters

  • On resistanceRon0.00001 Ω

    ≥ 0

    On resistance, in ohms: the slope of the conducting branch. 0 or more; the default 10 µΩ is near-ideal.

  • Off conductanceGoff0.00001 S

    ≥ 0

    Off conductance, in siemens: the slope of the blocking branch, so the leakage is Goff · v. 0 or more; the default 10 µS leaks 10 µA per volt.

Equations

Modelica
v = p.v − n.v, i = p.i
Closed (control false): v = Ron · i
Open (control true): i = Goff · v

Implementation

Modelica Standard Library 4.1.0Modelica.Electrical.Analog.Ideal.IdealOpeningSwitch
MSL documentation

Assumptions and limitations

  • Switches instantly with no arc. Interrupting an inductive current gives a large voltage spike.

See also

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