Study On Safety Assessment Of Human Electromagnetic Exposure In Electrical Vehicles

In recent years,with the increasing attention to the development of renewable energy in the world,reducing the dependence on fossil energy,reducing the pollution of the environment,promoting the electric vehicle industry has become one of the urgent problems to be solved.With the increasing sales of electric vehicles,countries all over the world have formulated the corresponding overall ban schedule of fuel vehicles.Therefore,the related theory and technology research to electric vehicles will be the core development of the vehicle industry in the coming decades.Unlike oil-fired vehicles,electric vehicles completely rely on electric energy as the power source of the whole vehicle.During the operation of electric vehicles,electric energy is transmitted from the power battery group to each power electrical component in the vehicle through the power bus.Due to the size and space limitations of the car body,passengers may be close to the high-power electrical components of the electric vehicle.At this time,passengers in the car would be exposed to the electromagnetic environment generated by the high-power devices.If exposed to the electromagnetic environment for a long time,it may have certain impact or damage on the human tissues of passengers.Therefore,it is very important to carry out the research on the electromagnetic exposure safety assessment of electric vehicles.The research would not only guide the design of electric vehicle electrical system from the perspective of electromagnetic compatibility,but also evaluate the safety of electromagnetic exposure of passengers in the electric vehicle compartment,and has a certain reference value for the formulation of electromagnetic exposure industry standards of electric vehicle.In addition,it could also improve the public awareness of the electromagnetic environment of electric vehicles,eliminate the fear of the safety to the electromagnetic exposure of electric vehicles and the fear of occupational diseases.The main innovation of the thesis are as follows: using the basic principle and method of electromagnetic dosimetry,the distribution of magnetic flux density,induced electric field intensity and induced current density in the trunk and central nervous system of adult and child passengers under the influence of static electromagnetic field,low-frequency electromagnetic field of power cable and different body materials are quantitatively studied,and the distribution rules of these induced fields in different tissues of human body are obtained.By comparing the results with the relevant electromagnetic exposure limit standards defined by ICNIRP,the safety of electromagnetic exposure of adult and child passengers under the action of the static field and the low-frequency field is determined.I It effectively complements the research on safety assessment of electromagnetic exposure of electric vehicles.On the basis of numerical calculation,we also measured the distribution of electromagnetic environment in the electric vehicle compartment,and further verified the safety of electric vehicle electromagnetic exposure from the the view of experimental point.It provides a reference for the establishment of electromagnetic exposure safety standards of electric vehicles,and provides a reference for electromagnetic exposure safety protection of electric vehicles.Firstly,the thesis describes the development of electric vehicles,and the research status of electromagnetic exposure in complex electromagnetic environment and electromagnetic environment of electric vehicles at home and abroad,and puts forward the importance of safety assessment research on electromagnetic exposure of electric vehicles.Then,the basic structure and main working principle of electric vehicle are introduced,and the causes of electromagnetic environment of electric vehicle are discussed.The numerical calculation method adopted in the thesis is also introduced,and the main electromagnetic exposure assessment standards at home and abroad are compared.The human body model of adult and child,the electromagnetic environment model of electric vehicle body and power cable are constructed.The influence of DC power cable of electric vehicle on adult and child passengers in different positions is analyzed.The distribution of magnetic flux density in the human trunk and central nervous system under the static field of power cable is calculated.Compared with the relevant standards defined by the ICNIRP,we conclude that under the static field exposure,the electromagnetic exposure of adult and child passengers is far lower than the exposure limit defined by ICNIRP,so the static field will not pose a threat to the safety of passengers.Considering the large low-frequency harmonic current in the power cable of the electric vehicle in the starting,acceleration and deceleration state,the distribution of the induced electric field intensity,the induced current density and the magnetic flux density in the human trunk and the central nervous system of adult and child passengers under the effect of the low-frequency current is calculated and analyzed,and the calculation results are compared with the ICNIRP.Through comparison,we found that under the action of the low-frequency current,the electromagnetic exposure of adult and child passengers is also far lower than the exposure limit defined by ICNIRP.Thirdly,because the driver is the most frequently exposed person in the electromagnetic environment of the vehicle,considering the safety of the driver,when the vehicle body materials are steel,aluminum alloy,non-magnetic steel,ferronickel and other six different materials,the distribution of the induced electric field strength,the induced current density and the magnetic flux density in the driver's trunk and the central nervous system are calculated.In order to study the influence of different vehicle body materials on the shielding effectiveness of electromagnetic exposure and provide theoretical guidance for the selection and design of body materials of electric vehicles.Finally,the low-frequency electromagnetic field measuring equipment is used to measure the electromagnetic field distribution in two popular electric vehicle compartments in Lanzhou,and the different distribution of the field in different electric vehicle compartments is studied.The reliability of the numerical calculation results is verified by the experimental measurment and the safety of the electromagnetic environment in the electric vehicle compartment is further verified from the view of experimental point.