Electromagnetic Shielding And Compatibility Analysis Of In-vehicle Systems

With the increasing complexity of the electromagnetic environment,the electromagnetic interference problem of automotive electronic equipment is gradually increasing,and the research on the electromagnetic compatibility of vehicles is of great significance to the safety of vehicles.In the future informatization battlefield,vehicles may face the powerful threat of nuclear electromagnetic pulse,and electronic equipment will be damaged or interfered,which will have a serious impact on the mobility and safety of vehicles.Therefore,it is very important to conduct electromagnetic compatibility research and analysis on vehicle-mounted systems.This paper studies the electromagnetic compatibility characteristics of vehicle systems.Firstly,the thesis introduces the coupling method of electromagnetic pulses and the characteristics of high-altitude nuclear electromagnetic pulses.Secondly,the electromagnetic simulation software required for simulation and the algorithms involved in the simulation research institute are introduced.Finally,the entire automotive system is divided into three parts for research: vehicle structure,cables and antennas.Main tasks as follows:(1)Research the shielding effectiveness of typical structures and vehicle structures.In a typical structure,the electromagnetic leakage caused by strong electromagnetic pulses at different pore structures is studied.The pores are filled with materials for electromagnetic protection,such as wire mesh and heat dissipation holes.And analyze the changes in the shielding effectiveness of the cavity after filling.In the entire vehicle structure,strong electromagnetic pulses are irradiated at different incident angles to study the shielding effectiveness of different cabins in the vehicle.The results show that the greater the aspect ratio of the aperture,the more serious the electromagnetic leakage caused.Therefore,in practical applications,it is necessary to choose apertures with a small aspect ratio as much as possible,avoid using slender slits,and use shielding material wires or heat dissipation holes at vehicle windows or vents to improve the shielding effectiveness of the cavity.(2)Study the electromagnetic compatibility characteristics of cables.Firstly,analyze the radiation performance of different types of cables on a finite plane.Secondly,compare the effects of different cable types,loads,and spacing on crosstalk between cables.Finally,study the influence of electromagnetic wave irradiation of cables in different incident directions and different polarization directions on the sensitivity of irradiation.On this basis,study the cable layout and electromagnetic compatibility characteristics analysis inside the vehicle.The grounding protection measures of cables are also studied.In cable protection,use cables with shielding layers as much as possible,and use multi-point grounding.At this time,the shielding effect is the best.(3)Study the electromagnetic compatibility of vehicle antenna systems.Firstly,analyze the performance and pattern of different vehicle antennas.Secondly,study the coupling effect between the vehicle antennas,and compare and analyze the influence of the change of the distance between the antennas on the coupling degree under different carriers.Finally,the coupling degree between multiple antennas is simulated,and the optimal layout of the vehicle antenna is obtained.