modelACLine_RLC

Test model for a three-phase unbalanced RLC line

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

Information

This example demonstrates how to use an RLC line model to connect a source to a load.

The model has four different loads. The loads sc_load, sc_load1, sc_load2, sc_load3 represent short circuits R=0. The current that flows through the load depends on the resistance, inductance and capacitance of the line.

The parameter R, L and C are such that at the nominal frequency fnom = 60 Hz the respective resistance and reactances are all equal to 10 Ω.

The lines used in this example have a T model (see Buildings.Electrical.AC.ThreePhasesUnbalanced.Lines.TwoPortRLC). The equivalent impedance of the line on each phase is equal to

ZEQ = R/2 +jXL/2 + (R/2 +jXL/2)(-jXC)/ (R/2 +jXL/2 -jXC)

that in this case is equal to ZEQ = 15 + j5 Ω.

Given the equivalent impedance of each phase, and a voltage with an RMS value of 100 V produces a current equal to I = 6 - j2 A flowing through phase 1.

Notes

(1) Note: The line model RLCLine_sc is the same as RLCLine_1 but it uses dynamic phasors.

(2) Note: The line model RLCLine_2a has a current that is different from the one passing in RLCLine_1 because the series of two T line models is different from the sum of the two separate line models.

(3) Note: The line models RLCLine_3a and RLCLine_3b have currents that are 50% of the other lines because they are in parallel.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.ResistanceRBase3*10Base value for the line resistance
Modelica.Units.SI.InductanceLBaseRBase/(2*Modelica.Constants.pi*60)Base value for the line inductances
Modelica.Units.SI.CapacitanceCBase3*0.1/(2*Modelica.Constants.pi*60)Base value for the line inductances

Components

TypeNameDefaultDescription
Sources.FixedVoltageEVoltage source
Loads.Impedancesc_load1Short circuit load
Loads.Impedancesc_load2Short circuit load
Loads.Impedancesc_load3Short circuit load
Loads.Impedancesc_loadShort circuit load
Lines.TwoPortRLCRLCLine_scRLC line that connects to the short circuit
Lines.TwoPortRLCRLCLine_1RLC line that connects to load 1
Lines.TwoPortRLCRLCLine_2aRLC line that connects to load 2
Lines.TwoPortRLCRLCLine_2bRLC line that connects to load 2
Lines.TwoPortRLCRLCLine_3aRLC line that connects to load 3
Lines.TwoPortRLCRLCLine_3bRLC line that connects to load 3

Revisions

  • October 8, 2014, by Marco Bonvini:
    Created model and documentation.