Safety device for an overhead electrical line designed to supply power to transportation vehicles and method for operation of this device

摘要

The present invention relates to a safety device for an overhead electrical line designed to supply power to transportation vehicles. It comprises a plurality of peripheral units (9), each electrically connected to a single mesh (8) of the line (1), signal generating means (10) designed to send, into the corresponding meshes (8), control signals at a frequency close to the resonance frequency of the mesh (8), analyser means (11) designed to receive response signals from the mesh (8) following the sending of the control signals and to recognise significant variations therein when the control signals are no longer tuned to the resonance frequency of the mesh (8) owing to the presence of a fault condition. The safety device (3) also comprises a logic control unit (12) electrically and operationally connected to the signal generating means (10) and to the analyser means (11). In this way, the logic control unit (12) is able to actuate the actuator means (13) so as to form a short-circuit in the line (1) following the presence of a significant variation in the response signals.