Research On Current Mode Magnetically Coupled Resonant Wireless Power Transmission Technology

Current-mode magnetically coupled Resonant wireless Power Transmission(CRPT)is an emerging technology in the field of wireless power transmission.Compared with the traditional magnetically coupled technology,it is more suitable for applications with light load and long transmission distance to achieve higher voltage conversion efficiency under the condition of lower receiving voltage.By controlling the reverse current,the output voltage is adjusted without using DC-DC converters.Because CRPT and the traditional voltage-type systems are respectively suitable for the light and heavy loads or long and short transmission distances,a reconfigurable system formed by the current type and the voltage type has a wide application prospect for extending the range of the transmission distance and the load.In this paper,the CRPT and the reconfigurable CRPT systems are modeled,analyzed,designed,and optimized.Firstly,the research status of CRPT technology is introduced.Then the working principle and characteristics of the voltage and current resonant systems are analyzed,respectively.The applications of the reconfigurable system which combines with the voltage-and the current-modes are introduced.Secondly,based on the theory modeling of current resonant system,the CRPT system is designed.The effectiveness of the system is verified by simulations and experiments.The designed system,with an operation frequency of 1 MHz and a coupling distance of 3 cm between coils,can output 2.16-V voltage when the peak to peak value of input voltage is 1.15 V,achieving a voltage conversion efficiency of 1.6.Finally,by adding impedance matching networks to the voltage-mode of the reconfigurable CRPT system,any load could be matched to the optimal one to realize the maximum power transmission.The effectiveness of the design scheme is verified by simulations and experiments.The experimental results show that after the reconfigurable CRPT system performs impedance matching,the system output power maintains 16.8 m W operating at voltage-mode for arbitrary load under 6.31-V input voltage.