Study On The Finite Element Modeling And Electromagnetic Radiation Interference Simulation For Automobile

With the development of modern electronic technology, electrical and electronicequipment are widely applied in the automobile, making it within increasinglycomplicated electromagnetic environment, and the importance of the automotiveelectromagnetic compatibility is more and more significant, which directly impacts onthe performance, the cost and the time to market of the vehicle. Traditionalelectromagnetic compatibility design is design-prototype production-testing, and ifthe EMC test fails, rectification or redesign is needed, which will extend the designcycle, increase the high design costs. Using the computer to simulate and predict itsEMC in the automobile design stage, identify the interference problem, providetheoretical guidance for design engineers can strangle much design risk before thestereotypes of the automobile products, thus shortening the design cycle, saving designcosts.Due to the complexity of automotive structures, all electrical and electroniccomponents meeting the appropriate EMC standards does not mean that the vehicle isalso to meet the EMC requirements. So, under the support of National Natural ScienceFoundation of Automotive EMC prediction and research of key technologies forelectromagnetic interference suppression, to achieve vehicle level electromagneticcompatibility simulation predictions, this paper investigate those contents:(1)The FEM and Edge-based finite element method (EB-FEM) for thethree-dimensional are introduced, the EB-FEM is selected as the numerical algorithmfor automotive EMC simulation.(2) This article studies the techniques of vehicle modeling, for the limitations oncomplicated structure object modeling of simulation software, presents a new methodnamed multi-software method for modeling, and uses this method to establish a certaintype of car the whole vehicle finite element model.(3) This article analyzes the radiated interference mechanism of ignition systemswhich is the largest sources of EMI in the vehicle, and establishes its radiation model inthe vehicle model. The radiated electric field level of vehicle ignition systems obtainedby measuring the common-mode current of primary power cord of the ignition systemsas excitation source.Simulation and test results verify the correctness of the simulation.On this basis, this article simulates and analyzes the field distribution inside and outside of the vehicle.(4) For the material of bodyshell is good conductor metal, and bodyshell is publicland, which will generate electricity, this paper analyzes the mechanism of thebodyshell’s current, concludes that surface current density is approximately equal tosurface magnetic field when a higher frequency according to the theory of boundaryconditions of the magnetic field strength and the skin effect, and then simulates thecurrent distribution of bodyshell using the finite element simulation software.