Mathematical Model of Contact Resistance in Pantograph-Catenary System Considering Rough Surface Characteristics

Pantograph-catenary system is a key component of high-speed railway. Under high speed and strong current operation conditions, the surface roughness of the sliding electrical contact between contact wire and slide changes continuously. It will cause the fluctuation of contact resistance and lower the electrical contact property of the system. Therefore, it is of great significance to study the relationships between the contact resistance and surface roughness characteristics. In this article, lots of current-carrying friction experiments were carried out under different contact pressure, contact current, and sliding speed conditions. A roughness tester was used to measure the roughness of the contact surface after the experiment. Four characteristic parameters were proposed to describe the roughness. They are the root mean square and the maximum peak height of the rough surface, the peak count, and the curvature radius of asperity, respectively. The function relationships between these characteristic parameters and experimental conditions were obtained and discussed. On the basis of Greenwood–Williamson contact model, a new mathematical model of contact resistance in the pantograph-catenary system considering rough surface characteristics was established and verified. It can be used to further study the current conduction mechanism of sliding electrical contact in pantograph-catenary system and evaluate the electrical contact performance.