Research On Equivalent Model And Shielded Grounding Of Cable Bundle Of Vehicle In High Intensity Electromagnetic Pulse Environment

With continually development of vehicle becoming electronic and intelligent,electrical and electronic equipment of modern car are becoming more and more,thus problem of electromagnetic compatibility of vehicle is prominent.Cable and cable bundle network connect with key equipment,which are important guaranties of mobility and safety of vehicle,as well as vital approach to couple electromagnetic interference.High altitude electromagnetic pulse(HEMP)is characterized by short duration,high energy,wide range coverage,which is a typical example of high intensity electromagnetic pulse,and will be a main threat to electronic devices and systems of car in the future war environment.Therefore,it is necessary to study on electromagnetic effect of vehicle cable bundle in high intensity electromagnetic pulse environment as HEMP for an example,which has guidance significance for designing electromagnetic protection scheme of vehicle.Simulation and test are the important method of studying the coupled effect of car cable in high intensity electromagnetic pulse environment.Because of large number and variety of car wire,it is difficult to calculate effect of complete wires,no matter by numerical simulation or experimental test.Aiming at solving problem of high complexity and low computation efficiency of vehicle cable,this paper research on simplified modeling of cable bundle to realize fast computation of cable coupled effect.Based on above achievements,the shielding ground method of car cable is further analyzed,which can provide reference for electromagnetic pulse protection of car cable research.The main contents and innovations are as follows:(1)The cable grouping method of cable equivalent model are improved,and an effective fast equivalent cable bundle modeling method is proposed.Applied with multi-conductors transmission theory,formula of equivalent cable radius is deduced,and the method to calculating parameters of equivalent cable containing position,height above ground,equivalent terminated loads are given.Considering both frequency response of excitation source and dependent load,the problem of frequency dependent loads,pure resistance and their hybrid connections are studied.The coupled current in reference wire are analyzed before and after simplified,and the complexity are reduced while precision are guaranteed.What's more,the applicability of the algorithm is investigated.(2)Based on fast cable bundle equivalent algorithm,some different application scenarios of cable electromagnetic coupled effect calculation method are researched.The simplified modeling method for two dimension branched cable are proposed,which are sorted by branched angel.The related equivalent parameters including branched location,branched angel are also given,and procedure of figuring is simplified.Then the influence of grounding plane position,conductivity of ground and rolling amplitude of rugged ground are studied to verify the precision of equivalent method.Typical location vehicle wires such as engine compartment wires,cockpit wiring harness,and chassis harness are modeled by using the proposed method,and the results show good precision.(3)A novel non-terminal points shielding grounding method of vehicle cable is proposed.The effect of grounding locations on sheath of shielded cable and grounding discharge effect are studied.And the relationship between grounding location of shielded wire and core wire current under HEMP is analyzed.What's more,surface current distribution regularity of vehicle under irradiation of HEMP are considered.Based on the regularity,some suggestion are given to grounding method of car cable on surface of vehicle,which can provide theory reference for electromagnetic protection of car vehicle.In a word,this paper research on fast modeling of vehicle cable from aspects of principle and applications.In addition,the relationship of grounding locations on sheath of shielded cable and grounding effect are studied under HEMP.And surface grounding current rule of vehicle are analyzed,which will do help to HEMP characteristic study and provide reference method for vehicle electromagnetic compatibility technology research.