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Safety Analysis And Biological Effects Of Electromagnetic Field In Wireless Charging Space For Electric Vehicles

Posted on:2021-05-15Degree:MasterType:Thesis
Country:ChinaCandidate:Y GaoFull Text:PDF
GTID:2432330626464117Subject:Electrical engineering
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In recent years,electric vehicles(EV)wireless charging has been applied in the new-energy-resource field,based on the principle of wireless power transfer technology.Nowadays,the electromagnetic safety of its charging environment has become a research hot-spot at home and abroad.The electromagnetic safety and biological effects of electric vehicle wireless charging system are analyzed as follows in this paper.1.The international research status of bio-electromagnetic safety and the electromagnetic standards of electric vehicle wireless charging technology are described.By selecting electromagnetic field of medium frequency within 10 MHz,the electromagnetic safety standards in IEEE?GB8702?ICNIRP are summarized.Besides,the basic limit and derived limit value principle are introduced.2.The safety simulation of the electric vehicle wireless charging system is researched.3Ds MAX modeling software is used to precisely build refined human organs model and to simplify the finite element mesh.To realize the coupling calculation of biological heat transfer and electromagnetic energy in multi-physical fields,electromagnetic and thermal physics parameters of the real human body are given to organ models.When system frequency is 85 k Hz and powers are 7.7,11,22 and 33k W,the electromagnetic exposure of human body in the interior and exterior space influenced by the aluminum chassis is studied under different charging positions.3.A set of calculation and analysis method of electromagnetic radiation indexes and safe distance for human body in EV wireless charging environment is developed.By the analysis of body different levels with human organs,the electromagnetic exposure distribution of external body and internal body is obtained calculated in the charging environment.In the near-body-surface space,the electric field and magnetic induction intensity indexes corresponding to the body levels are calculated and to be judged with derived limit.The internal induction electric field and current density indexes at the levels inside body are calculated and then compared with the basic limit.Then,safe distances of different organs inside the body are restricted,which are more serious than those of the whole body earlier.Above all,the differences betweenthe internal and external exposure for organs distribution are summarized.Two kinds of safe distances for near body space and internal body electromagnetic field are obtained.Finally,the specific absorption rate and temperature rise of human body in the environment are studied.4.The human experiment is according to the setting conditions of the simulation system.Not only is the experimental system of EV wireless charging built,but also a set of electromagnetic exposure measurement scheme of human near the body surface is developed in the charging environment.Corresponding to the body organ level,the electromagnetic test points are selected in the near-body-surface space.The distribution of magnetic induction and electric field intensity in different space positions are obtained in experimental results,which confirm the correctness of the limit index and safety range in the simulation results.5.Biological vivo exposure experiment is built in EV wireless charging experimental platform.The charging condition is set as 40-60 k Hz?33k W,which leads to the maximum magnetic exposure of test positions is 5m T.Accordingly,the biological exposure effect of organism organs can be ensured under the condition which is higher than the test intensity of human body.The results is shown as follow.Under the system exposure condition of 1,2,4 weeks and 2 hours every day,the spleen and lymph indexes analyzed by FCM and SPSS method were not affected.Under the long-term exposure of continuous three months and two hours every day,the organ sections are treated based on HE staining method,except for the glandular reduction in testis and ovary sections,the other organs had no significant effect;it is shown by ELISA method that the levels of testosterone and progesterone are decreased,but fit the normal reference values.
Keywords/Search Tags:EV wireless charging, Human organ models, Body-level analysis method, Multi-physical coupling calculation, Biological exposure experiment
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