Study On The Electromagnetic Environment And Shielding Technology For The Electric Vehicle Wireless Charging System

As an emerging technology,wireless energy transmission technology has the advantages of high reliability,practicality and safety,and has huge application prospects in many fields.One of the main applications is in the wireless charging of electric vehicles.This article takes electric vehicles as an application scenario,focusing on the study of the electromagnetic environment safety and electromagnetic shielding technology under wireless charging status.The high-frequency magnetic field generated by the wireless charging system will exist in the space around the electric vehicle and pose a potential threat to human safety.Its distribution is the result of the combined effects of transmission coil parameters,car body structure,and car parking position.Therefore,according to the distribution characteristics of the electromagnetic field of the electric vehicle wireless charging system,it is necessary to find out the area where the magnetic field strength exceeds the standard,and design an electromagnetic shielding method to improve the safety of the electromagnetic environment in this area.This paper first theoretically analyzes the circuit structure of the wireless charging system,derives the transmission efficiency expression,and theoretically calculates the magnetic field generated by the resonant coil to derive the expression of the magnetic field strength around the two coil coupling mechanism.Based on the theoretical analysis of the topology structure of the resonance compensation network and the magnetic field model of the coupling mechanism,the topology structure suitable for the wireless charging system of the electric vehicle is selected and the design of the coupling mechanism model is completed.Secondly,the selected resonance compensation network,coupling model and electric vehicle model established with Solid Works modeling software are input into the finite element simulation software COMSOL for joint simulation.The electromagnetic field distribution inside and outside the car under the alignment and offset of the transceiver coil is obtained,and the international electromagnetic safety standard ICNIRP-2010 is used to evaluate the safety of its electromagnetic environment.Aiming at the electromagnetic excess area obtained by the simulation,two shielding methods,active and passive,are designed to optimize the electromagnetic environment.Through the comparison of different materials,shapes,structures,coil turns,etc.,active and passive shielding methods suitable for wireless charging of electric vehicles are designed.Finally,based on the circuit simulation of the wireless charging system established in MATLAB,an experimental platform for electric vehicle wireless charging system was built.The magnetic induction strength of the surrounding space before and after the addition of passive shielding is tested,and the effectiveness of the shielding method is verified,which provides a reference for the optimal design of the electromagnetic environment when the electric vehicle wireless charging technology is actually applied.