Research on lightning protection performance and rail transient potential for catenary of Qinghai-Tibet Railway

Because of the poor geographical environment of Qinghai-Tibet Railway, the catenary is vulnerable to strike by lightning. At the same time, as the Qinghai-Tibet Railway is laid on the bridge, the probability of lightning striking the rail increases with the bridge rising. As a result, the rail transient potential rises which seriously threatens the safety of equipment and personnel along the railway. Based on the engineering situation of Qinghai-Tibet Railway, this paper establishes a lightning catenary simulation model by the electromagnetic transient simulation software ATP-EMTP. By combining the Elecrto-geometric Model(EGM), we analyzes the lightning withstand level of the catenary at different elevations and bridge heights. We also analyzes the influence of lightning current waveform and rail grounding resistance on rail transient potential when lightning strikes the rail. The simulation results show that the lightning withstand level of the catenary meets the requirements of regulations, and reducing the steepness of lightning current and rail ground resistance can effectively restrain the rise of rail transient potential.