Contents I. Introduction
Catenary system (also known as the overhead contact line system) is one of the key constituents of traction power supply system (TPSS) and it plays the important role of transmitting power to electric locomotives. However, the catenary system mostly works outdoors without backup devices, and therefore, it is more vulnerable to external environmental factors compared with other indoor power supply equipment [1], [2]. Through years of historical records, it has been shown that external factors are the main causes contributing to the catenary failures [3]. China’s railway lines span across wide areas, which are remarkably influenced by geographical factors, especially for railway lines over the length of 1000 km. For example, the Sichuan–Tibet Railway under construction in Southwest China passes through high-altitude zones with drastic changes in geographical conditions. The frozen soil, landslides, earthquakes, geothermal, and other geographical factors act on different sections of the railway lines. Meanwhile, during the operation of the catenary system, it is subject to different meteorological factors. For Beijing–Shanghai Railway, which is the main artery of the north-to-south railway network in China, the catenary systems in southern coastal regions are susceptible to thunderstorms and typhoons, whereas the catenary systems in northern regions are more susceptible to ice and wind. In different regions, the meteorological factors affect the catenary system in distinctive ways. However, once the catenary failure occurs, it will cause the trains to be delayed or even canceled, resulting in severe economic losses and unfavorable social influence. Therefore, in order to develop targeted maintenance strategies and thus guarantee the safety and reliability of the catenary system, it is significant to comprehensively evaluate the catenary system risk with full consideration of geographical and meteorological factors and integrating the consequence of catenary failures.
