An experimental investigation of the thermal behaviour of a moving pantograph's strip

In a railway system, electrical power supply is ensured by a sliding contact between the catenary wire and the pantograph collector strip. The contact between the two interfaced materials involves many physical phenomena which generate a temperature increase of the strip-wire system and its related deterioration. Determination of the temperature distribution in the contact strip is complex and in this paper, we propose an experimentally study of all the different parameters that contribute to the temperature increase of the strip. The tests were carried out on a test bench able to reproduce the electromechanical sliding contact between the collector strip and the contact wire and so the associated wear. Specific thermal instrumentation was created to accurately visualize all the thermal phenomena in the strip. The results show the temperature distribution in the strip for many configurations of the entry parameters such as: electrical current, applyed contact force, train velocity, stagger motion amplitude, air flow velocity and material type. Finally, an analyse of all the collected results is done and many conlusions can be assumed, namely: - The Joule effect induced by the electrical current circulation into an electrical contact resistance, as well as the temperature increase due to friction are the most important heat productions of the system. - The intern thermal parameters of the collector strip caracterise the thermal evolution of the system. The analyse of specific numbers such as solid Peclet number, system response time or thermal diffusivity allows some basic principles related to the material quality in function of the train power supply strains. - Thermal peaks appear in particular times and positions. Such phenomena give a glimpse, from a thermal point of view of the worse phases during a train travel.