| Wireless power transmission technology is a very flexible,convenient and reliable power transmission method.It has been extended to electric vehicles,marine exploration and implantable medical equipment and other application fields and will gradually become the main development direction of energy transmission in the future.With the popularization of wireless energy transmission technology and the exposure of its security problems,the electromagnetic problem in wireless energy transmission has become the core issue of common concern of experts,scholars and the public.Since there is an electromagnetic field that diffuses outward during the working process of this technology,it is necessary to install shielding facilities on the coupling mechanism,and it is extremely important to control the electromagnetic field around the coupling mechanism within a safe range.This paper mainly studies the electromagnetic shielding mechanism of the magnetically coupled resonant wireless power transmission system,aiming to explore the influence of electromagnetic shielding materials on the system performance,system structural parameters and the space magnetic field in the non-working area.In order to obtain a better shielding effect,from the perspective of composite materials,this paper designs a new shielding structure that can effectively control the electromagnetic field of the coupling mechanism,ensuring the safety and health of users.The main research contents and work are as follows:Firstly,this paper analyzes the basic principle and composition of the magnetic coupling resonant wireless power transmission system,establishes the equivalent circuit model of the series-series compensation structure of the wireless power transmission system,and obtains the main factors affecting the output power and transmission efficiency of the system.factor.And the electromagnetic shielding technology is expounded from three aspects: shielding type,shielding principle and shielding effectiveness.Secondly,the simulation model of the coupling mechanism is designed by using finite element software,and the electromagnetic environment of the coupling coil in free space is simulated.Then,magnetic shielding and electrical shielding materials were added to the system coupling mechanism,and the influence of shielding materials on system structural parameters and magnetic field distribution was analyzed one by one.Then,aiming at the defects of ferrite shielding materials,a new type of magnetic shielding mechanism based on quartz fiber/nanocrystalline reinforced resin composite material was designed,and the corresponding simulation model was built.The simulation results show that the new shielding structure effectively improves the inductance parameters of the coupling coil,and reduces the leakage magnetic field in the non-working area and the shielding edge space,which makes the cooperation between the system and the shielding mechanism more perfect.Finally,the prototype of the magnetically coupled resonant wireless power transfer system required for the electromagnetic shielding experiment was built,and the quartz fiber/nanocrystal reinforced resin matrix composite was prepared.Based on the electromagnetic measuring device,experiments were carried out on different shielding structures.The results show that the new shielding structure proposed in this paper can reduce the magnetic flux density in the edge area of the shield by 30.2% and the magnetic flux density in the central area by 23.7%,which verifies the distribution of the electromagnetic field in the system coupling area and the effectiveness of the new shielding structure. |
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