Transmission Characteristic Analysis Of Wireless Charging System Based On Magnetic Resonance

As a new power transmission technology,wireless power transmission technology makes all kinds of electrical equipment get rid of the shackles of cable wiring,and makes the charging process convenient and fast.As an important branch in the field of wireless power transmission,magnetic resonance wireless power transmission technology has long been the focus of domestic and foreign scholars,but there are still many problems to be solved.In this paper,the transmission characteristics of the magnetic resonance wireless charging system are studied from the perspective of transmission efficiency.The influence factors of the transmission efficiency of the magnetic resonance wireless charging system are analyzed.The influence of the spatial position of the resonance coil on the transmission efficiency of the wireless charging system is studied.The multiple transmit coil structure is used to improve the anti offset ability of the wireless charging system and improve the transmission efficiency decrease caused by coil offset.Based on the equivalent circuit model of the magnetic resonance wireless charging system,the transmission efficiency formula is derived,and the main influencing factors of the transmission efficiency of the magnetic resonance wireless charging system are analyzed.In order to analyze the influence of resistance of coil on the transmission efficiency,three kinds of coils were fabricated respectively,including copper graphene coating,galinstan liquid metal and copper.The change trend of AC resistance with frequency of different material coils is studied,and the influence of different coil material on transmission efficiency is analyzed.In order to analyze the influence of coil mutual inductance on the transmission efficiency,based on the mutual inductance theory of resonance coil,a model of resonance coil with different shapes is established by finite element simulation software.The influence of different shapes of resonance coil in different position relationship on the transmission efficiency of wireless charging system is analyzed.In view of the problems existing in the actual situation of the receiving coil horizontal offset and angle deflection at the same time,the influence of the asymmetry between the resonance coils on the transmission efficiency of the magnetic resonance wireless charging system is studied.Based on the mutual inductance theory of resonance coil,the change of magnetic flux in different directions of angle deflection after receiving coil horizontal deviation is studied by finite element simulation software.It is proposed that angle deflection in different directions after receiving coil horizontal offset will have different effects on the transmission efficiency,and the simulation software and experiment are used to verify it.Then it is extended to the change of transmission efficiency in the general space position of the coil of wireless charging system.Aiming at the problem of transmission efficiency reduction caused by coil offset of wireless charging system,the model of wireless charging system with multiple transmit coil structure is established by finite element simulation software,and the influence factors of the transmission efficiency of the model are studied.Based on the equivalent circuit model and mutual inductance theory,the influence of receiving coil position and transmitting coil position on the transmission efficiency of wireless charging system with multiple transmitting coil structure is analyzed.It is found that the wireless charging system with multiple transmit coil structure has a certain anti offset ability and improves the transmission efficiency decrease caused by coil offset.The purpose of this paper is to analyze the factors that affect the transmission efficiency of magnetic resonance wireless charging system,and provide some guidance for the structure design and optimization of magnetic resonance wireless charging system in practical application.