| Energy-saving and emission reduction technologies have become the hotspot of current research with the increasing consumption and environmental pollution.In order to realize the application of these new technologies effectively,battery electric vehicle have become the focus of the times.At present,more and more people are buying battery electric vehicles,which has alleviated the energy crisis while emerged some new problems.Wireless charging technology converts electrical energy into magnetic field and can be transmitted between electrical devices.During this time,some magnetic leakage will occur inevitably.Moreover,the frequency and power used in wireless charging of electric vehicles are large,and whether it is a threat to human health is not sure.This thesis mainly evaluates the safety of electromagnetic exposure of charging coils during wireless charging of electric vehicles.The thesis introduces relevant researches of domestic and international firstly.Wireless charging technology research has been carried out for several decades with remarkable achievements.This technology of electric vehicles advances from laboratory to the market gradually.However,there is little research on the safety of wireless charging electromagnetic environment.Then introduces the wireless charging principle of electric vehicles that provides theoretical basis for simulation.In order to evaluate the electromagnetic environment safety effectively when charging,which uses 3D modeling software to build a simple electric vehicle wireless charging system that is similar to the actual one.This thesis focuses on the electromagnetic exposure safety of human body?especially the central nervous system?.So the human sitting posture model and the three-layer ball head model were established for calculating by according to the international standard ratio.The electric vehicle has a high charging frequency.This thesis is dedicated to calculate the distribution of magnetic induced strength and induced electric field strength in human head when the charging coil was located in different locations in the car.The system was charged at a frequency of 10.27 MHz.Comparing it with the limits set by the International Commission for Non-Ionizing Radiation Protection?ICNIRP?for the purpose of safety assessment.The results show that when the charging coil is located at the front of the vehicle body,the magnetic induction intensity values generated in the various tissues of the body are greater than in the middle.Similarly,the electric field of human also satisfies this law.Not so in the head and brain,however.The magnetic induction intensity of all tissues are much smaller than the recommended values of public electromagnetic exposure by the ICNIRP except ankle.The electric field and magnetic field distribution values of the head are larger than the values in the brain.As the height of the human body increases,the magnetic induction intensity values decrease in turn.The maximum magnetic induction intensity in the head is 6.17×10-3?T,accounting for 6.71%of the threshold,and the maximum induced electric field strength is139 mV/m,accounting for 0.5%of the threshold.Meanwhile the maximum magnetic induction intensity in the brain is 5.95×10-3?T,accounting for 6.46%of the threshold,and the maximum induced electric field strength is 31.3 mV/m,accounting for 0.11%of the threshold.Both of them are much smaller than the public electromagnetic exposure recommendations developed by ICNIRP.Which indicates the high frequency electromagnetic exposure produced by coil isn't detrimental to one's health while the vehicles is charging. |
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