Electromagnetic field modelling for transmission line distributed parameters of railway track

Railway track transmission line model: calculation of rail conductance by means of boundary element method

“…Railway tracks, from the electrical point of view, can be considered as a pair of very long linear electrodes dissipating part of the return current into the soil. Being the longitudinal dimensions of the track much greater than the transversal ones, it is allowed to assume cylindrical symmetry for the problem and to treat the pair of rails by means of a distributed transmission line model [10]; thus, if we limit our analysis to the DC case, the two circuits: rail 1-earth and rail 2-earth can be considered as two transmission line circuits, both with earth return, that carry the transverse electric and magnetic mode and that are mutually interacting through conductive coupling.…”

Characterization of railway line impedance based only on short‐circuit measurements

“…The experimental identification of the primary line parameters is essential. Some of these parameters, R and L, can be accurately determined from (7) and (8). Nevertheless, the computation of other primary line parameters can become complex, since they are affected by the properties of the soil, and by the rail-to-rail conductance and capacitance.…”

“…As can be observed, the length D and environmental conditions should be chosen in order to avoid the approximation Z sh (2x) ≈ 2Z sh (x). After the characteristic values are obtained, the primary line parameters (R, L, C and G) are computed according to (7), (8), (9) and (10).…”

“…The characterization of such a kind of electrical circuits can be performed by using models with concentrated [6] or distributed parameters [7]. The point to decide which model is the most suitable for a specific application is determined by the relationship between the circuit size and the wavelength λ (m) of the applied signal.…”

Modelamiento Electromagnético de los Sistemas Eléctricos Ferroviarios para Estudiar su Compatibilidad

“…Los investigadores se han interesado en el problema de identificar esos parámetros, y han usado el método que tiene a los campos electromagnéticos como base; utilizan el método de los elementos finitos para calcular la distribución de los campos eléctrico y magnético a lo largo y entre los rieles, proceso con el que obtienen los parámetros electromagnéticos (Hill et al, 1999(Hill et al, , 1999(Hill et al, -1, 2000. Es un método preciso que permite describir exactamente la geometría de los rieles.…”