Research On Lightning Effect Analysis And Lighitning Protection For The Motive Target On Ground

Lightning is a nature phenomenon on atmosphere discharge,often accompanying with catastrophic lightning effect.In practical cases,aerospace system targets are usually inevitable to the lightning strike,due to their special working environment.What's more,thoes electronic devices with electromagnetic sensitive component inside the systems which are also vulnerable to the lightning electromagnetic interfernece.Nowadays,with the development of lightning protection technology,the technique on lightning protection for aerospace system stationary grounding target(eg launch site and rocket)is advanced.However,as to the motive target on ground(eg.special vehicle),the lightning protection research is still in margin,especially to the research on lightning protection for aerospace system special vehicles.In fact,the lightning protection research for the motive target on ground has a great siginificance in the lightning research.In some practical cases,those aerospace special vehicles usually need to work in an open wide environment,or on a motive stage.Until now,it is still hard to use any existed stationary lightning protection method on a motive target,which makes it becomes more vulnerable and is easier become degrade under lightning environment.Meawhile,the theory on lightnig strike probability prediction for the motive target on ground is still in lack.On the purpose of protecion the aerospace system motive targets on ground being striked by lightning,a systemic research on lightning effect analysis and lightning protection methods should be performed.Supporting by the National 13'h Five-year Reasearch Program,a reaearch on lightning effect and lightning protection for motive target on ground(aerospace special vehicle)is performed in this paper.The studies of major innovative structure are as follows.(1)Propose an ennovative method for prediction the probability of getting struck upon the motive target on ground.Based on the long air gap discharge model,an equivalent lightning learder model is established in the paper,and the development progress of lightning leader is simulated by the model.Then a prediction on the lightning strike point tendency of aerospace system special vehicle is performed by the Monte Carlo(MC)method,an ennovative method for prediction the probability of getting struck upon the motive target on ground is proposed and the probability statistic on lightning strike to the moving vehicle is obtained.(2)Propose a kind of a numerical analysis model for aerospace system special vehicle,and perform a lightning effects simulation analysis on the special vehicle under a 200kA lightning current by Transmission Line Matrix(TLM)method.Moreover,a systematic lightning testing is also performed on a special vehicle,truly measured the lightning effects on the vehicle,which make a comprehension research on the lightning induced effects for aerospace system special vehicles.(3)Propose a modified four-level EMC assessment model.Based on the proposed model,the EMC performance on the vehicular communication system of motive target on ground can easily be assessed hierarchically,from the physical layer to the signal layer.And an assessment application example is also taken to a kind of military vehicular communication system.The results confirm the effectiveness and practicability of the proposed model.(4)Propose some lightning protection methods and advices for the motive target on ground.The research on lightning protection for the motive target on ground includes both the direct lightning strike protection and the lightning indirect-effect protection.In the direct lightning strike protection research,an outer lightning protection method and an inner lightning protection method are both discussed,respectively.As to the lightning indirect-effect protection research,some protection advices for the aerospace special vehicles are also discussed on the point of EMC three elements.The lightning protection methods and advices provided in this paper can serve as a reference for lightning protection of aerospace system motive grounding targets.