Study On The Influence Factors Of Attracted Lightning Characteristics Of High-Speed Railway Catenary On The Viaduct

With the rapid development of national economy, the contradiction between supply and requirement on transportation is becoming more and more serious, and the high speed railway is developing very fast rely on its own unique advantages. According to the latest development and research about lightning protection of high speed railway, points out the importance of high speed railway lightning protection research. And because that our country has set up a large number of viaducts in the high speed railway, the catenary’s height above ground level increases and becomes more vulnerable to lightning. This paper mainly researches on the influence factors of attracted lightning characteristics and lightning withstand level of high speed railway catenary on the viaduct.In this paper, with the practical situation of high-speed railway, based on the electromagnetic simulation software ATP-EMTP, establishes the simulation model of high speed railway catenary on the viaduct. Then analyses the influence rule on lightning withstand level of catenary while lightning strike on the different lines and lightning strike on different stanchion and different grounding resistance and different viaduct’s height. Research results show that the AF line has the largest probability of suffering lightning strike and the lightning withstand level of insulator on AF line is lowest when lightning strike on the catenary, and with the increasing of ground resistance and viaduct’s height, the lightning withstand level of catenary decreased obviously.Secondly, establishes the leader propagation model (LPM) of high-speed railway based on the developing mechanism of lightning in order to analyze the attracted lightning characteristics of high speed railway catenary on the viaduct. The influence rule of lightning current amplitude and viaduct’s height on the attracted lightning range of direct lightning and induction lightning is studied. Research results show that with the lightning current amplitude increasing, the attracted lightning range of direct lightning and induction lightning both increased. And with viaduct’s height increasing, the attracted lightning range of direct lightning increased, but the attracted lightning range of induction lightning decreased. According to this, get the fitting calculation formula L(I, h)= a(I)h+b(I) which can be used as a reference of the lightning protection design in high-speed railway.Finally, the influence rule of lightning current amplitude and viaduct’s height on the distribution probability of direct lightning and the lightning flashover times is researched. Research results show that with the viaduct’s height increasing, the critical lightning current amplitude of induction lightning increased and so the probability of occurring induction lightning decreased, the lightning flashover times and the direct lightning flashover times both increased although the induction lightning flashover times decreased because the percentage of direct lightning is very high. And should take effective protective measures against direct lightning on account of the threat to normal operation of high speed railway catenary by direct lightning.