modelIdealSwitchWithArc

Ideal switch with simple arc model

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n), Modelica.Electrical.Analog.Interfaces.ConditionalHeatPort (Partial model to include a conditional HeatPort in order to describe the power loss via a thermal network).

Information

This model is an extension to the IdealSwitch.

The basic model interrupts the current through the switch in an infinitesimal time span. If an inductive circuit is connected, the voltage across the switch is limited only by numerics. In order to give a better idea for the voltage across the switch, a simple arc model is added:

When the Boolean variable off signals to open the switch, a voltage across the opened switch is impressed. This voltage starts with V0 (simulating the voltage drop of the arc roots), then rising with slope dVdt (simulating the rising voltage of an extending arc) until a maximum voltage Vmax is reached.

     | voltage
Vmax |      +-----
     |     /
     |    /
V0   |   +
     |   |
     +---+-------- time

This arc voltage tends to lower the current following through the switch; it depends on the connected circuit, when the arc is quenched. Once the arc is quenched, i.e., the current flowing through the switch gets zero, the equation for the off-state is activated i=Goff*v.

When the Boolean variable off signals to close the switch again, the switch is closed immediately, i.e., the equation for the on-state is activated v=Ron*i.

Please note: In an AC circuit, at least the arc quenches when the next natural zero-crossing of the current occurs. In a DC circuit, the arc will not quench if the arc voltage is not sufficient that a zero-crossing of the current occurs.

Please note: In case of useHeatPort=true the temperature dependence of the electrical behavior is not modelled. The parameters are not temperature dependent.

Parameters

TypeNameDefaultDescription
SI.ResistanceRon1E-5Closed switch resistance
SI.ConductanceGoff1E-5Opened switch conductance
SI.VoltageV0Initial arc voltage
SI.VoltageSlopedVdtArc voltage slope
SI.VoltageVmaxMax. arc voltage
BooleanuseHeatPort (from ConditionalHeatPort)false= true, if heatPort is enabled
SI.TemperatureT (from ConditionalHeatPort)293.15Fixed device temperature if useHeatPort = false

Connectors

TypeNameDefaultDescription
PositivePinp (from TwoPin)Positive electrical pin
NegativePinn (from TwoPin)Negative electrical pin
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_aheatPort (from ConditionalHeatPort)Conditional heat port

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.PowerLossPower (from ConditionalHeatPort)Loss power leaving component via heatPort
SI.TemperatureT_heatPort (from ConditionalHeatPort)Temperature of heatPort
BooleanoffIndicates off-state (but maybe not quenched)

Revisions

  • June, 2009 by Christoph Clauss
    adapted to OpenerWithArc
  • May, 2009 by Anton Haumer
    CloserWithArc initially implemented