Sensing the Health of the Catenary-Pantograph Contact on Railway Vehicles with Radio Receivers: Early Results

Overhead lines or catenaries are the most common method to supply electric energy to trains, at least in modern railway lines. Electric trains collect energy using a pantograph which is in physical contact with the catenary. However, this sliding contact is not perfect because of many factors: vertical displacements, wear of the contact strip, aerodynamic effects, geometry defects, etc. These imperfections may cause sparks and electric arcs which could seriously damage the pantograph, the catenary and increase the operational costs of the railway line. The usual approach to know the condition of this contact is installing video cameras in the top of the train to determine where, when and why sparks and arcs happen. Given that both sparks and arcs cause a significant EM interference, in this paper we propose a methodology to sense the health of the catenary-pantograph contact using radio receivers tuned in the frequencies where this interference appears. The objective of this measurement campaign is not to perform an academic characterization of the physical phenomenon but to begin working on a practical condition-based maintenance system. Moreover, some early results of this work are provided based on measurements from a Metro de Madrid train in Line 6 whose voltage is 600 V DC.