modelCompareLineTrunks

Compares oLine and tLine splitting lines into trunks

Extends from Modelica.Icons.Example (Icon for runnable examples).

Information

This example shows a way to look at the traveling wave moving along a power line.

This wave can be seen looking at intermediate points of the line, looking at both OLine (several segments per line trunk) and TLine models.

OLine in the lossless case is less accurate, since shows oscillations that are not present in a distributed parameter line but, since it allows the addition of resistances and conductances, allows evaluation of losses.

Suggested tests:

7 segments per trunk, lossless

Run the model as it is. Since resistances and conductances are very small in OLine, the simulation is substantially lossless.

Show in the same plot ramp.y, oLine1.p2.v, oLine2.p2.v, oLine3.p2.v, oLine4.p2.v.

Show in another plot, simultaneously, ramp.y, tLine1.p2.v, tLine2.p2.v, tLine3.p2.v, tLine4.p2.v. Here oLine shows unreal oscillations, which, however, reduce if the number of segments per trunk increases.

50 segments per trunk, lossless

Try increasing this number from 7 to 50 using parameter segsPerTrunk, and look at the same plots as per test 1

50 segments per trunk, losses

Leave segsPerTrunk=50, change r1 to 1e-3 Ω, re-simulate: the effect of losses is visible only on the oLine plot.

Parameters

TypeNameDefaultDescription
SI.ResistanceRload1000Load resistance
Realr11e-6Resistance per meter
Realg11e-12Conductance per meter
Reall11e-6Inductance per meter
Realc11e-11Capacitance per meter
SI.Lengthlen100e3Length of line
IntegersegsPerTrunk7Segments per trunk
SI.Velocityc1/sqrt(l1*c1)Speed of EM wave
SI.Timetdlen/c/4Transmission delay
SI.Impedancez0sqrt(l1/c1)Characteristic impedance for very high frequency

Components

TypeNameDefaultDescription
Modelica.Blocks.Sources.Rampramp
Modelica.Electrical.Analog.Sources.SignalVoltagesrcLump
Modelica.Electrical.Analog.Basic.Groundground1
Modelica.Electrical.Analog.Lines.OLineoLine1
Modelica.Electrical.Analog.Lines.OLineoLine2
Modelica.Electrical.Analog.Lines.OLineoLine3
Modelica.Electrical.Analog.Lines.OLineoLine4
Modelica.Electrical.Analog.Basic.ResistorR1
Modelica.Electrical.Analog.Sources.SignalVoltagesrcDistr
Basic.Groundground2
Modelica.Electrical.Analog.Lines.TLinetLine1
Modelica.Electrical.Analog.Lines.TLinetLine2
Modelica.Electrical.Analog.Lines.TLinetLine3
Modelica.Electrical.Analog.Lines.TLinetLine4
Modelica.Electrical.Analog.Basic.ResistorR2

Revisions

  • May, 2021 implemented by Massimo Ceraolo, University of Pisa