| Radio energy transmission is a non-contact energy transfer mode with the help of electromagnetic field,and it is a new technology which gets rid of the shackles of traditional transmission media.The improvement of the transmission efficiency and application range of wireless power transmission technology has always been a goal pursued by scientific researchers because the technology provides various conveniences to all walks of life.However,it is a pity that the research so far has been limited to the transmission efficiency of power electronic rectifier,control algorithm,resonant topology,inverter and coil structure,while there is little research on electromagnetic metamaterials.Based on the unique negative permeability of metamaterials,combined with the theory of negative refraction and coordinate transformation,the control of electromagnetic waves is studied in this paper,which not only effectively suppresses the divergence of electromagnetic waves in the wireless power transmission process,but also an effective attempt to improve the transmission efficiency and application range of wireless power transmission.In this paper,the principle of wireless power transmission technology is first sorted out and analyzed,and the relationship between transmission efficiency and system components is drawn based on the equivalent circuit theory.Then,in view of the influence of four traditional resonant compensation networks on the transmission performance of the system,the resonant radio energy transmission system of SS resonant compensation network is deduced theoretically,and the conclusion that the compensation capacitance is affected by the system constitutive parameters,load resistance and coupling coefficient is drawn.Based on the system transmission model,it is concluded that the SS resonance compensation network system has a higher transmission efficiency when the load resistance is small,and can maintain a higher output power and efficiency when the coupling coefficient changes.Furthermore,the SP resonance compensation network system can maintain the high transmission efficiency of the system under the condition of a large load.This is suitable for heavy-load systems,but it is largely affected by the mutual inductance coupling coefficient.Secondly,based on the negative refraction theory,perfect lens phenomenon,inverse Doppler phenomenon and inverse Cherenkov phenomenon of electromagnetic metamaterials,the unique electromagnetic properties of electromagnetic metamaterials are analyzed,and the feasibility of combining electromagnetic metamaterials with radio energy transmission is verified in theory.Moreover,the theoretical preparation methods of negative permeability and negative permittivity are deduced,and the electromagnetic parameters of the medium materials to be measured are inversely deduced according to the relationship between the scattered field and the amplitude of the electromagnetic field.In addition,the amplitude of the whole field can be measured directly by using the S-parameter inversion algorithm,and the error of the result is small.Thirdly,based on the special electromagnetic characteristics of the electromagnetic metamaterial,the simulation modeling of the radio energy transmission system is completed from the electromagnetic metamaterial resonant ring to the whole magnetic concentrator.The self-resonant frequency of the resonant ring is determined by frequency scanning,the focusing ability of the electromagnetic open resonant element array to the electromagnetic field is analyzed,and the transmission coefficient and refractive coefficient of the electromagnetic wave under different rotation angles are obtained.Furthermore,the transmission efficiency of the transmission system is analyzed through the lumped port,and the effects of resonant frequency,compensation mode,transmission distance and electromagnetic incident angle on the radio energy transmission efficiency are verified by experiments.Finally,with the transmission mode of combining the radio energy transmission with the metamaterial,the electromagnetic coordinate transformation method can be used to design the electromagnetic metamaterial structure reasonably according to the needs of the electromagnetic parameters of the transmission system,and then control the electromagnetic wave,and realize the efficient transmission of the system.On the premise of ensuring the efficiency,the transmission efficiency is improved,and the hyperplane designed by the electromagnetic coordinate transformation method can also control the transmission direction and improve the influence factors of the coaxial placement of the relay coil according to the different distribution of the medium. |
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