Study On Electromagnetic Environment Effects Of Vehicle’s Subsystem And Shielding Effectiveness Of Enclosure

The performance of electronic circuit systems on vehicles directly affects the securityfunction of automobiles in electromagnetic environment. In order to make the equipmentson vehicles functioning well, it is necessary to take effective shielding measures forsensitive subsystems. The electromagnetic environment effects and shielding effectivenessof enclosure are both the important constituent and fundamental theory of vehiclesprotection technology against electromagnetic pulse. The study has a great significance toimprove the survival ability of vehicles in complicated electromagnetic environments.The paper studys ECU’s electromagnetic environment of vehicle and shieldingeffectiveness of enclosure, which are based on CST simulation software and building ofthree elements’ electromagnetic models of electromagnetic interference.In order to study the electromagnetic environment effects of subsystem，the optimizationmodel was firstly built in simulation platform, observation point was set on the ECUposition.Then the simulation has been down by18times and the simulation datas of25groups have been processing. By analyzing the incident direction and polarizationdirection of EMP effect on ECU’s electromagnetic environment,found that the couplingeffect of slot on hood is much more serious than that of doors and inlet grille, thedifference of electric field intensity peak can be more than48kV/m. The model wascalculated in simulation platform by the excitation of EMP, the electric field intensity andshielding effectiveness of vehicle’s shell were analyzed with the result of energy range andtypical resonance points. At last the trend of vehicle’s surface current was analyzed by theresonance points in1GHz.The core problem of study on enclosure shielding effectiveness is to choose theobservation points, the paper firstly analyzed the electromagnetic environment ofenclosure, chose typical observation points by electric field intensity peak datas of80observation points. In order to research shielding effectiveness of enclosure systematicallyand obtain the trend of shielding effectiveness by different conditions,7groups ofenclosure models were built, the total number of times that completed simulations is28, and34groups of simulation datas were processed.To study the shielding effectiveness of enclosure in vehicle, the model of enclosure wasfirstly modified according to the measured datas. Then the shielding effectiveness trendaffected by polarization direction and different band of EMP were analyzed. Simulationresults showed that the enclosure had a favorable shielding effect to ECU of vehicle.Lastlya set of complete evaluation indicator system for enclosure shielding performance wasconstructed, the calculation method of targets was given according to analytic hierarchyprocess method and fuzzy theory, it can offer an objective evaluation method for theseenclosures of vehicles.The main contributions are listed as the following:(1) Constructed the optimization model of vehicle from the perspective of slots andapertures on vehicle. Determined the method and step of studying electromagneticenvironment effects of vehicle’s subsystem, analyzed the ECU’s electromagneticenvironment and shielding effectiveness of vehicle’s shell in typical EMP environment,which can provide central theory reference for the study of these subsystems.(2) The principles of basic simplifying in the enclosure model under the attack of EMPwere proposed. To counter the problem of selecting observation points in enclosure, ananalyzed method based on multi-points’ environment was given in the paper.Analyzed theshielding effectiveness of enclosure in vehicle for the first time, which brought the resultof an architecture system of shielding effectiveness of enclosures.(3) Determined the types of electromagnetic environment characteristics, constructedprocessing modules based on Matlab. Explore and preliminarily establish a set of completeevaluation indicator system for enclosure shielding performance, which can offer anobjective evaluation method for these enclosures of vehicles.The above works systematically analyzed the electromagnetic environment effects ofvehicle’s subsystem and shielding effectiveness of enclosure, which is the importantconstituent of vehicle’s electromagnetic environment, and also provide consultation valuefor the design of vehicles against EMP damage.