The impact of multilayer ground and buried conductors on ground potential rising
Résumé
The electromagnetic modelling of phase-to-ground short-circuits in a railway environment is essential to optimize the protections against ground potential rising. Two particularly important points are defined: a) the determination of the ground structure in terms of its electric resistivity; b) the introduction in the model of a buried conductor in the zone of the phase-to-ground short-circuit. In this paper, ground resistivity will firstly be investigated. Different ground models will be compared. Secondly, the behaviour of the ground potential rising will be analysed with the presence or not of buried conductors. Different ground constructions will be used. Results are interpreted in term of the threshold given in EN 50122.