Magnetic Field Model And Radiation Suppression Of Wireless Power Transfer System Based On Regular Polygon Coil

Wireless power transfer(WPT)technology,as a new type of energy transmission method,has got rid of the comfort of charging wires in the traditional method,has the advantages of flexibility and convenience,and gradually attracted widespread attention from scholars at home and abroad.With the deepening of research,the performance of WPT system such as transmission efficiency,transmission power,stability and transmission distance can basically meet the needs of general products such as mobile phones and audio,but before the popularity of various wireless charging equipment,the electromagnetic environment Must meet safety targets.Especially in high-power application equipment,such as electric vehicles and smart home products,the human body is in an electromagnetic over-standard environment for a long time,which will cause serious harm to health.Therefore,effective electromagnetic environment analysis methods and suppression measures are of great significance to the development of WPT systems.Taking the electromagnetic radiation analysis and suppression of the WPT system as the research object,the research work is carried out from three aspects: regular polygon planar coil magnetic field modeling,WPT system electromagnetic environment analysis and magnetic field radiation suppression.The unified magnetic field model of the regular polygon coil wireless energy transmission system is derived;through the principle of electromagnetism,the magnetic induction strength of the energized straight wire is solved by the Biot-Savart law,combined with the Cartesian coordinate system,the energized wire is generated at any point in space Calculate the magnetic induction intensity of the coordinate axes X,Y and Z,and calculate the total magnetic induction intensity of the multi-section energized straight wire at the change point by vector summation.Through the use of cutting circle,the circular coil is equivalent to a polygonal coil,and then a unified magnetic field model suitable for the regular polygonal coil of the WPT system is established,and the magnetic field radiation of the square,hexagonal and circular coils is compared and analyzed.The WPT system experimental platform was built to verify the deduced magnetic field model,and the effectiveness of the proposed coil magnetic field model and numerical calculation method was proved,which provided theoretical support for the calculation of the magnetic induction intensity in the surrounding environment of the WPT system.Taking the square coil as a research case,based on the derived unified magnetic field model and finite element simulation,the magnetic field distribution of its WPT system under different transmission power and offset conditions is simulated,and it is evaluated using domestic and foreign electromagnetic safety standards.Furthermore,the influence of the transmission coil wire diameter,turn spacing and turns on the system magnetic field radiation is further analyzed,which lays a theoretical foundation for the radiation suppression and optimization of the WPT system.For the electromagnetic environment safety problem of WPT system,the coil configuration scheme was selected according to the unified magnetic field model of the regular polygon coil WPT system.On this basis,based on the principle of electromagnetic shielding,the multi-layer shielding structure combining metal shielding materials and non-metallic shielding materials was discussed to shield and suppress the magnetic radiation of the wireless energy transmission system.And through the establishment of Ansys finite element simulation and experimental platform,the effectiveness and feasibility of the radiation suppression measures studied were verified.