Research On Electromagnetic Compatibility Of Vehicular Electrical Systems

Nowadays, with the development of vehicle electrification, more and moreelectronic devices, which are collectively known as the vehicular electrical system,have been applied to the vehicle’s control and drive systems．The vehicular electricalsystems send strong electromagnetic emission out when they perform normally, thenthe electromagnetic background become very poor．It’s also the electromagneticemission that will generate electromagnetic interference (EMI) to the communicationsystem and electronic devices mounted on the vehicles through coupling pathways,affecting their working state, even making them unable to work.To solve the electromagnetic interference problem of vehicular electrical systemto mounted equipment, it’s necessary to analyse the electromagnetic compatibility(EMC) problem of the vehicular electrical system．Firstly current situation of thevehicular electrical system’s EMC has been described, on the basis of these, theresearch content and research purposes were proposed．Secondly, the major potentialEMI sources of the vehicular electrical system were analyzed, and the functionprinciples of the interference sources has been studied separately．The electromagneticemission models were established, and the rationality and correctness of the modelshas been proved by EMC tests．Then the electronic emission model of the table-drivingsystem has mainly studied through the analysis of PWM frequency control technology,and the accuracy of the model is verified by the simulation and test．The EMI couplingmodel of the vehicular electrical system to communication and electronic equipmentwas established next．Finally, the protection methods which are suitable to thevehicular electrical system’s EMC were analyzed, and the technology of APFCsuppressing electron equipment harmonic was investigated．The Boost APFC circuitbased on LT1248was formed, and the relevant EMC tests have completed smoothly．The content of this thesis can solve most of motor vehicles’ EMC problems andoffer foundation for the EMC design during the process of motor vehicle plan,meanwhile, the APFC printing plate can be applied to most of power supply, includingthe vehicular power supply.