Analysis And Suppression Of Conducted Electromagnetic Interference In Z-Source Inverter Systems Of New Energy Vehicle

In recent years,people’s awareness of environmental protection is getting stronger and stronger.Automobile exhaust has been regarded as the main source of pollution by environmental protection departments and environmental protection agencies at all levels,which is the main cause of haze weather.For the health of the people,the development of new energy vehicles has become a broader development situation,as the main direction of future automotive development.Compared with traditional fuel vehicles,new energy vehicles are more environmentally friendly,but because of the addition of a lot of power electronic components in the car,while improving the efficiency of power utilization,the problem of electromagnetic compatibility(EMC)becomes more and more obvious,and the related electromagnetic interference(EMI)is also more and more serious.If the system is affected by electromagnetic interference in the car operation,not only is the normal work of its own system affected,but also other systems in the car.This poses a major hidden danger to the safety of the car.In view of the above problems,this paper will focus on the conducted EMI generated by Z-source inverter system of new energy vehicles,and analyze the causes and suppression methods.The main research contents are as follows:Firstly,the theoretical knowledge related to conducted EMI of Z-source inverter of new energy vehicles is analyzed and summarized,three basic elements of electromagnetic interference are introduced,the topology structure of Z-source inverter and the working principle of Z-source inverter are analyzed,and the causes of electromagnetic interference source of Z-source inverter and coupling path of conducted EMI are studied.Secondly,the conducted EMI of Z-source inverter for new energy vehicles is studied.In the frequency range of conducted EMI,the interference source model,motor model,cable model and LISN model of Z-source inverter system are constructed.These models are respectively built in MATLAB software,and the conducted interference spectrum of interference voltage and interference current is carried out from common mode interference and differential mode interference.At the same time,the parasitic capacitance of switch tube to ground in Z-source inverter is studied.By changing the parasitic capacitance of switch tube to ground,the change of electromagnetic interference with parasitic parameters is analyzed.Finally,the suppression method of conducted EMI in Z-source inverter system of new energy vehicle is studied,and a filter structure is designed to block the propagation path of conducted EMI,so as to achieve the purpose of restraining conducted EMI.The circuit built by MATLAB software is used to realize simulation verification.The simulation results verify the suppression effect of passive EMI filter,which has shown that the passive EMI filter can effectively suppress conducted EMI and it can suppress conducted electromagnetic interference accurately and effectively.