Design And Research On High-efficiency Wireless Power Transmission Coil For Magnetic Coupling String-string Resonance

Traditional electric wires or cables have many problems such as aging and inconvenience in transmitting electric energy.They are increasingly unable to meet the needs of people’s production and living,and Wireless power transmission technologies have unparalleled advantages such as safety and reliability,and are increasingly subject to more and more attention.For Magnetic coupling string-string resonance wireless power transmission systems,the main task of this thesis is to optimize the coil design and research.First of all,it introduces the system structure,working principle and development status at home and abroad of the type of wireless power transmission technology.By comparing the characteristics of various transmission types,Magnetic coupling resonance wireless power transmission method are selected as platforms for research.Secondly,several main magnetic field theories are introduced and deduced,the equivalent coil circuit model is analyzed,the application range of different capacitive compensation structures is introduced,and the string-string(SS)capacitive compensation structure is selected.According to circuit theory analysis,the maximum transmission efficiency is improved by increasing the quality factor and the coupling coefficient of the coil.Then,through the resistance,inductance theory and Magnet simulation analysis of the coil structure parameters,determine the coil type,wire material,wire radius,the best pitch distance,the optimal number of turns and the coil inner radius,to obtain a coil high quality factor.The mutual inductance and magnetic simulation were used to analyze the influence of the positions of the two single coils on the mutual inductance,and the relationship between the mutual inductance and the outer radius and spatial position of the coil and the relationship curves were obtained.The mutual inductance and the two coils were analyzed with emphasis on the parallel coaxial.The relationship between the radius and the transmission distance determines the outer radius of the coil.Finally,by measuring the resistance,inductance and quality factor parameters of the wound single-turn and multi-turn coils,the magnetic coupling string-string resonance wireless power transmission experiments of two multi-turn coils were performed to measure the maximum transmission efficiency.The corresponding Magnet simulation and the co-simulation with Matlab were compared to find that the error between simulation and experiment results was small and regular.The coil parameters selection based on the Magnet simulation was verified,and the coilparameter selection steps were summed up.The design proposal of the structural parameters of the magnetic coupling string-string resonance wireless power transmission coil proposed in this paper has the advantages of good economy,high transmission efficiency,and flexible design,which provides the basis for the later efficiency research and production applications.