Influence Of The Modulation Method Of The Inverter To The Electric Drive System For The Electric Vehicle

With energy, environmental protection and other issues have becomeincreasingly prominence. Electric vehicles are becoming a hot research.Electric vehicles with a DC/AC inverter which electromagneticenvironment is very complex, and many factors that produceelectromagnetic interference, good EMC design is smooth loading andreliable operation of the key. As a source of interference, Inverter itself，external electromagnetic interference. Especially due to the high degreeof integration requirements of electric vehicle inverter IGBT driver boardstacked directly on the IGBT, the increasingly high demand for EMC.Order to suppress electromagnetic interference of the inverter good, manyscholars have done a lot of relevant research. Produce electromagneticinterference must have three factors, namely: a source of electromagneticinterference (emitter), sensitive to interference, the receiving device(receiving body) and coupling path. Emitters be suppressed, can be fromthe source to prevent the occurrence of electromagnetic interference,which is the most effective method for suppressing electromagneticinterference. In recent years, the random modulation as an effectivemethod to suppress conducted electromagnetic interference from thesource has been widely studied.This paper focuses on the basic principle and method of randommodulation, including random modulation, three single randommodulations: proportion of zero vector modulation, random centerposition modulation and random frequency modulation. Randomfrequency and random center position of double-random modulation.Simulate and analysis those four strategies. In order to further thesimulation, the actual combination of random proportion of zero vectormodulation and electric drive systems used in electric vehicles, the benchtest results show that the inverter output side of the line voltage and phasecurrent conduction electromagnetic interference has been better inhibition,in the four times subcarrier frequency and at frequencies above the effectof having a good diffusion spectrum. The simulation and experimentresults show that the random modulation can improve the electromagnetic compatibility of electric vehicle electric drive system with good results,the modulation method does not require additional hardware cost,convenient to use, electric vehicle motor drive system electromagneticcompatibility can be improved provides a viable solution.