IMPROVED POWER SUPPLY SYSTEM FOR AN OVERHEAD CONTACT LINE

This power supply system (2) for an overhead contact line (4), which comprises a contact wire (6) consisting of a plurality of conductive sections (10, 30, 50, 70) separated by insulating sections (20, 40, 60), comprises power supply substations (120, 140, 160), each conductive section being connected, on the side of an upstream end, to an upstream substation via an upstream controlled switch (135, 155, 175) and, on the side of a downstream end, to a downstream substation via a downstream controlled switch (114, 134, 154). This system comprises a detection device (230, 250), associated with a conductive section (30, 50) to be monitored, which comprises a means of emitting a characteristic signal (S1, S2) at an upstream or downstream end of said conductive section and a receiving means capable of receiving the characteristic signal at the other end, the receiving means modifying the value of a status signal (S3, S4) applied to an actuation control circuit for opening the downstream switch and/or the upstream switch.