| Due to the vigorous development of electronic technology,the power consumption of the portable electronic is bigger and bigger.Under the precondition of what the battery technology itself cannot be obtained in the short time,wireless charging technology becomes a feasible and convenient solution.At present,electromagnetic induction and resonant wireless charging has been concerned widely.Compared to the induction wireless charging,resonant wireless can not only charge in the short distance,but also support multiple devices and has very large development.At first,researching the resonant wireless charging system,analyzing and discussing the wireless charging system structure and working principle,guidelines should be followed in the process of energy transfer.Then establish mathematical model of resonant wireless charging.Secondly,resonant wireless charging is studied,the study finds that the charging efficiency is the highest when the critical coupling.Then propose adaptive resonant wireless charging mode according to different charging requirement at the scenario of charging multiple deceives simultaneously,namely the transmitter can charge accordingly according to the actual charging demand of different receiver electronics,for charging distance,residual capacity,power etc.This thesis mainly studies the relationship between distance and charging efficiency,analyzes the adaptive resonant wireless charging,makes the charging more flexible when charging simultaneously.Moreover,the thesis propose a priority algorithm according to the above adaptive resonant wireless charging mode,the priority algorithm is based on many parameters in order to achieve better charging system efficiency.The performance parameters involved in the algorithm are: battery capacity,real-time residual battery,real-time charging distance,load,charging priority subjective factor of the user etc.Compared with the wireless charging with no priority,the simulation results illustrate that the method in this paper improves the charging efficiency greatly.In addition,we propose performance evaluation process in the study of system performance parameters,design a resonant wireless charging coil antenna according the antenna evaluation criteria of performance parameters and two-port network analysis.We establish 3D modeling coil antenna via electromagnetic simulation software HFSS and make a research on performance characteristics of the coil antenna in this paper which is including: S parameters plot,standing-ware ratio,charging efficiency and 3D electromagnetic field distribution of the coil antenna.It turns out that when the coil antenna occurs resonance at the center frequency(2.8GHz),the input return loss is minimum(29.11dB)and charging efficiency can reach 84.15%.After joining in priority formula,the coil antenna charging efficiency is as high as 92.37%,and the charging system is more and more stable.In addition,the coil antenna after a performance evaluation has advantages on its lower cost and simple structure,so the design to the research of wireless charging has a good reference. |
