| Magnetically coupled resonant wireless power transmission technology(MCR-WPT)has gradually gained market recognition in the field of charging technology due to its advantages of high transmission power,high transmission efficiency,and a wide range of applications.However,with the increase in transmission power,the magnetic field problems derived from MCR-WPT have also increased.Therefore,research on electromagnetic shielding for MCR-WPT has begun to increase in recent years.This study focuses on the electromagnetic shielding structure in wireless power transfer(WPT)systems,with the objective of improving the overall system performance.The finite element analysis software Ansys Maxwell was to create a simulation model,enable investigation of the coupling mechanism in the electromagnetic field domain.The electromagnetic shielding mechanism was theoretically analyzed,and the structural scheme of the shielding magnetic core and the shielding aluminum plate was optimized.The effectiveness of the proposed optimization scheme was verified through simulation and experimentThis article presents an overview of the various development directions of Wireless Power Transfer(WPT)technology.It provides a comprehensive comparison and analysis of the current research status and existing challenges associated with coupling mechanisms in magnetic coupled WPT systems.The article also proposes the primary research focus of the study,which is the theoretical analysis and optimal design of electromagnetic shielding structures in MCR-WPT systems.Furthermore,the study aims to establish a complete WPT system platform for experimental demonstration.To simplify the prototype of the coupling mechanism and reduce the subsequent simulation time,the shielding core component of the electromagnetic shielding structure was modeled and simulated in the electromagnetic field domain using ANSYS Maxwell.Through the study of the magnetic induction line direction in the space of the coupling mechanism,the main reason why the shielding core produces abnormal heat source points under the high transmission power operation of the system is analyzed.The mechanism of shielding magnetic core is studied,and the effect of the area,thickness and shape of shielding magnetic core on magnetic induction circuit and coupling parameters is analyzed.A new design scheme and idea of shielding magnetic core are proposed with the aim of removing high heat source points and increasing coupling performance.Subsequently,electromagnetic field simulation was performed on the shielded aluminum plate component,and the magnetic field strength in the coupling space was compared between the shielded and non-shielded structures.The comparison was made to establish the significance of the shielded structure in the overall mechanism.By studying the eddy current effect and skin effect of shielding aluminum plate in high frequency alternating magnetic field,the magnetic shielding mechanism of shielding aluminum plate is clarified,and it is found that the core area of shielding aluminum plate is closely related to the area of shielding magnetic core.Combining the optimization process of shielding core and shielding aluminum plate,the overall design idea of electromagnetic shielding structure is put forward.The optimization scheme led to the development of a coupling mechanism for a magnetic resonant wireless power transfer(MCR-WPT)platform,which was then manufactured and tested.The parameters of the coupling mechanism were found to be in good agreement with simulation results.The efficiency of the system was measured to be greater than 96.71% in the range of transmission spacing between 50-100 mm and transmission powers between 1-10 k W.The peak efficiency reached 97.12%.The temperature of the shielded magnetic core was observed to remain below 31°C during continuous operation at 10 k W transmission power for 50 minutes,with a uniform distribution of heat.Additionally,the magnetic field strength 20 cm above the shielding aluminum plate was reduced to 1.658 μT,which is well within the safety limit of 27 μT for human electromagnetic exposure. |
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