| With the rapid developing of the electric vehicle, the EMC (electromagnetic compatibility) of the electric vehicle has been got more and more attention. The power train system of the electric vehicle has became the one of the major EMI (electromagnetic interference) sources of the electric vehicle,because it has high voltage, large current, complex structures and multiple coupling paths.The thesis does a research on the EMC of a native typical electric vehicle's power train system, basing on the methods of analyzing, testing, improving and comparative testing.The thesis's main contents are as follows:1. The EMI sources and transmission paths of the power train system are analyzed, basing on the theory of EMC.2. Three tests of the EMC of the power train system are designed according to the existing EMC standards of the vehicle and the characteristics of the electric vehicle. The tests are: electrical disturbances from power cables'conducted emission; electrical disturbances from AC power cables'conducted common-mode current; and electrical disturbances from electrical transient conduction along DC cables. The results of the tests show that: the inverter's high frequency switching characteristic is the main interference sources of the conduced and radiated EMI; the line voltage and line current of inverter contain more low-order harmonics at the low speed ; the vehicle's magnetic filed strength is serious at the high frequency.3. The solutions of improving the EMC of power train system are researched. The Spectrum of the inverter's switching waveform is calculated. It can provide the basis reference for the inverter's EMC designing. The Shielding methods of the power train system are designed. The suggestion of suppressing the common-mode current of power train system is proposed. Finally, the Comparison test proved that the solutions for improving the EMC of power train system can suppress the power train system's EMI immensely. The system's EMC is improved. |
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