Research On Coplanar Tree Network Structure Wireless Power Transfer System With Constant Voltage Output

In recent years,Wireless Power Transfer(WPT)technology has been widely used in electric vehicles,biomedicine and consumer electronics.Among the various modes of radio energy transmission,magnetic coupling resonant mode has the advantages of supporting medium transmission distance,high transmission efficiency and reliability.Nowadays,MCR-WPT has evolved from a static system to a dynamic system,from a single load to multiple loads.With the wide launch of small and medium-sized mobile devices with wireless charging function,the demand for systems that can wirelessly charge multiple different loads at the same time is increasingly urgent.But at present,the research of multiload in radio energy transmission system is not mature enough.In addition,the fixed position of the transmitter of the WPT system also determines the position of the receiving coil,resulting in the inflexible position of the transmitter and receiver of the system,which reduces the spatial freedom and flexibility of the system.Therefore,this paper proposes a load-independent tree network structure MCRWPT system,which has constant voltage output and dynamic transmitter-receiver characteristics.The main research content is as follows:(1)Elaborated the basic principle of MCR-WPT system,introduced the system coil circuit basic parameters.Four kinds of compensation structures are compared and analyzed,and the most suitable series-series compensation structure is selected.The theoretical method of analyzing radio energy transmission technology and the criterion of maximum power and maximum efficiency which should be followed in designing the system are described.(2)This paper proposes a dynamic transmitter-receiver MCR-WPT tree network structure system,the system structure and charge for creating new rules.Based on the theory of circuit and filter,the load independent constant voltage output and dynamic transmitter-receiver characteristics of the tree network structure system are proved by direct solution and equivalent circuit respectively.(3)Maxwell 3D software was used to compare and analyze the coupling effects of square and round coils,coaxial and coplanar structures.The system coil was determined to be a planar square structure,and ferrite was proposed to solve the problem of weak coupling of planar structure.Simulation software is used to determine the best ferrite placement between adjacent coils.(4)The constant voltage output principle of the system is analyzed by using the circuit and filter theory,the positions of the transmitter and the receiver are exchanged,and the influence of the change of the transmitter position on the output characteristics and transmission performance of the system is analyzed.Furthermore,the frequency domain circuit is established to verify the constant voltage output and dynamic transmitter-receiver characteristics of the system.(5)Set up three and four loads experimental platforms to exchange the positions of the transmitter and receiver.The experimental data prove the constant voltage output and dynamic transmitter-receiver characteristics,and the extensibility of the tree network structure.