modelLightningLosslessTransmissionLine
Extends from Modelica.Icons.Example (Icon for runnable examples).
Information
This example shows what happens when a lightning hits a transmission line. We consider a lossless single-phase equivalent circuit with two parts of the transmission line, each 50 km long. The RMS voltage is 380 kV / √3, the RMS load current is roughly 1090 A. Realistic parameters of the 380 kV transmission line are used. Note that after the source starts, the traveling wave arrives at the load 350 µs later. After 20 ms, a lightning (10/350 µs) with an amplitude of 10 kA hits the transmission line just in the middle. Note that the traveling wave hits source and load approximately 200 µs after the lightning hits the transmission line. Plot voltage and current at the load. Without overvoltage protection, the load would be destroyed. One could compare the results with that obtained by using a transmission line model taking losses into account.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Resistance | Rload | 200 | Load resistance |
| Real | r | 25e-6 | Resistance per meter |
| Real | g | 15e-12 | Conductance per meter |
| Real | l | 1e-6 | Inductance per meter |
| Real | c | 15e-12 | Capacitance per meter |
| SI.Length | len | 100e3 | Length of line |
| SI.Velocity | c0 | 1/sqrt(l*c) | Speed of EM wave |
| SI.Time | td | len/c0 | Transmission delay |
| SI.Impedance | z0 | sqrt(l/c) | Characteristic impedance for very high frequency |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Electrical.Analog.Lines.TLine | line1 | ||
| Modelica.Electrical.Analog.Lines.TLine | line2 | ||
| Sources.SineVoltage | source | ||
| Basic.Resistor | load | ||
| Basic.Ground | ground | ||
| Sources.LightningImpulseCurrent | lightningImpulseCurrent |
Revisions
- May, 2021 implemented by Anton Haumer, Technical University of Applied Sciences Regensburg