| Electromagnetic compatibility (EMC) of cars is the essential problemof the automobile and its accessory system equipment. With the rapiddevelopment of modern automobile technology, especially the automobileelectronic technology, the problem arisen from the EMC is getting greatlyfaster than that of the average developmental level of automotivetechnology. Electronic products, such as tracking control system (TCS),global positioning system (GPS), etc., being confined to a narrow space,make the EMC problem more complicated, especially for new energy vehicles.Due to the increase of driving motor and high power devices, compactarrangement of various types of electrical and electronics equipment, andthe devices in the vehicles being connected together by the electricalequipment, electromagnetic wave frequency distributes from kilohertz tomegahertz, forming an extremely complicated electromagnetic environment,which leads the EMC to one of the key issues in the study of the vehiclesand an important component of the system engineering.At present, assessment criteria of EMC for the product are almostaccomplished by using an anechoic chamber. However, with the developmentof software simulation it is necessary to consider the problems of EMCat the beginning of the design of daily electronic product. Meanwhile,simulation has been proved to be an economic and effective method fordiscovering and solving problems, reducing the design cost, and thusshortening the development cycle. Simulation is of most importance forapplication in high frequency phenomenon. Based on the above situations and combined with the Project of Jilin Provincial Science&TechnologyDepartment, this work focuses on the study of the simulation technologyof the automobile EMC.It is difficult to establish some mathematical model exactly for sucha large system of vehicle. Furthermore, every time of approximation orequivalent operation might indicate a scarification of EMC characters ofone system. Therefore, consideration of systematic methods and equivalentprinciples is extremely important. Most of the conventional analysismethods employ physical circuit, which tend to complicate the EMC problems.Synergetics theory indicates that each subsystem is different with othersin characters and they constraint and coordinate with each other in viewof the overall environments. Normally, large system or the overall systemcomposed of subsystem exhibits a common law, such as transformation,evolution and interaction under some certain conditions. Finding outfactors that might influence the systems and carrying out the latteranalysis, studying on complex system based on the overall exploration,deducing simple and effective mathematical model from theories, asuitable, effective and convenient way to settle EMC problem of cars couldbe expected.According to synergetics theory, parameters of slow relaxation arethe rate-determining step for the overall properties and development ofthe system. In this work, the electric circuit has been analyzed in thebasis of the measured data, mathematic model is established in accordancewith computational electromagnetics and uses to the study of subsystems;the EMC indicators like the interference degree, sensitivity, etc. areselected as order parameter based on the synergetics theory and the orderparameter equation is used for analysis of each subdomain fordetermination of the total impact of interference. A general approach hasbeen proposed to study on the EMC problems in electronic system of the cars that will exert greatly potential influence on the understanding andsettlement of EMC problems.Compared with the electric car, Journey Increasing Model ofElectric-auto with a Range Extender makes travel distance furtherincrease. The additional attachment mainly consists of generators,internal combustion engine (ICE) and the fuel tank. Obviously, theelectromagnetic compatible environment becomes more complicated, i.e.the EMC problems both relevant to starting of Permanent-MagnetSynchronous Motor and ignition switch in the situation of the deficiencyof the endurance mileage.The EMC relevant to the drive motor of extended range electric carand the ignition switch of extended engine has been studied and calculatedbased on the slow relaxation method, which figured out variables impactedon the electromagnetic interference of motor and analyzed the transientchange, such as motor starting moment. A corresponding mathematical modelof motor electromagnetic field has been established that includes threefactors, namely the sensitive equipment, the interference source, and thetransmission path. For equipment with same sensitivity, electromagneticcompatibility or not by car electrical system can be judged by comparisonof the value of electromagnetic interference and the sensitivitythreshold. According to the synergetics theory, it is no doubt to choosemagnetic energy density wmas order parameter.In-depth study for extended engine ignition system shows that theimportant factor that impacts on engine external jamming is the secondarycurrent which is regarded as a slow decay variable, and the equivalentmodel of the secondary loop for engines is built. Second, through the sparkcurrent simulation, some conclusions that suppress electromagneticinterference are made, such as appropriate to reduce the current etc.;the EMC research on DC-AC inverter and wiring harness of extended range electric car, with of the synergetic theory and related calculation method,analyzes the important parameters which impact on the calculation andsimulation of the power system and wiring harness. With the introductionof structure and operating principle of the inverter, electromagneticradiation source of the DC/AC inverter has been analyzed. Theestablishment of the model for each radiation source leads to a simulationimage, which further analyze their radiation degree. The crosstalkmechanism of transmission lines is explained and the crosstalk model ofthree conductor transmission lines (for multiple conductors) has isestablished. The crosstalk calculation model has been obtained with thelossless multiconductor transmission lines based on synergetic theory.The formula is derived to analyze the relationship between the loadimpedance and the characteristic impedance. For the uniform andnonuniform medium respectively, the crosstalk values of near-end andfar-end of multiconductor transmission lines can be calculated accordingto the derived formulas. The feasibility of the model is verified bycomparison with the results of the EMC studio. Finally, the ideas of systemtheory are used to predict and calculate the electromagneticcompatibility problem of the object (car) as a whole. An effectiveprediction software on dynamic system of extend-range electric car isdeveloped, and related suppression measures are given. Comparing with themeasured data, the feasibility of the synergetic theory on study ofautomobile EMC problems has been verified and a technology provided forthe study of electromagnetic compatibility on car system-level isdeveloped. |
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