| The technology of electromagnetic coupling resonance wireless energy transmission is to realize the transmission of electric energy from the power supply side to the load side by means of magnetic field and strong magnetic coupling resonance.Compared with other wireless energy transmission technologies,wireless transmission technology has the advantages of long transmission distance,less strict directivity requirements,and higher transmission power compared with other wireless energy transmission technologies.However,the selection of circuit parameters such as rectifier and inverter,coupling coil parameters,distance between coils and resonance frequency will affect the transmission efficiency and power.Therefore,how to design and optimize the system circuit to better adapt to longer distance power transmission,further improve the transmission efficiency and transmission power is the focus of future research.This article mainly studies the electromagnetic coupling resonance wireless energy transmission system from two angles of theoretical analysis and experimental simulation.In this paper,the mathematical model of the system is established based on the coupled mode theory.The analysis concludes that only when the coupling coefficient is much greater than the natural attenuation rate,can the high-efficiency energy transmission be performed,and the conclusion is that the transmission efficiency is highest under the resonance state.An equivalent circuit model of mutual inductance coupling is established.The effects of circuit impedance on transmission efficiency and output power are analyzed from a circuit perspective for three common coupling systems.The mathematical expressions of transmission efficiency and output power are obtained.The simulation analysis and comparison of the three coupled structure systems under the Multisim environment are carried out,and it is determined that the SS-type coupled structure has better output performance and stronger anti-interference ability than other structure type systems.Analysis of SS type wireless energy transmission system frequency,quality factor,coupling parameters,space and load characteristics,according to theoretical analysis in MATLAB simulation software for simulation.It was found that increasing the system resonance frequency,quality factor,and increasing the coupling of the coil can improve the system output power and transmission efficiency.The research on the influence characteristics of space and load found that the energy transmission of the system is directional.The system has the best space position and output load,so that the system has the best output performance.According to the theoretical research and simulation results of transmission characteristics,the system coupling coil is designed.The angle of the magnetic field was analyzed by ANSYS simulation software from the wire selection of the coil,the radius of the coil,the number of turns,the distance between turns,and the presence and absence of the core and the type of core.The selection requirements of the coil radius and the turn spacing are clarified,and the addition of a magnetic core can improve the system coupling and determine the ring structure as the magnetic core structure.The design of the transmitter and receiver circuits was selected,and the EMI filter-full bridge rectification and zero-voltage series resonance soft-switching inverter circuit and Buck-Boost circuit were selected as the transmitter and receiver circuits.In addition,a frequency tracking negative feedback system is added to the transmitter to compensate for the frequency splitting and spatial characteristic deviation of the system.Finally,the designed circuit and transmission characteristic theory are verified by experiment. |
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