Research And Design Of Matching Network In Low-power Wireless Power Transfer System

As an emerging power transfer technology,wireless power transfer has the advantages of being portable,safe and reliable compared to traditional wired power transfer.In recent years,it has attracted widespread attention.At present,there are mainly three kinds of technologies that are widely studied in this field: electromagnetic inductive coupling wireless power transfer technology,magnetic resonance wireless power transfer technology,and microwave transmission wireless power transfer technology.The magnetic resonance technology utilizes a coupling magnetic field in the near region to transmit energy,and the transmission distance thereof is far greater than that of the electromagnetic inductive coupling wireless power transmission and can reach several tens of centimeters.It can perform energy transmission with higher efficiency and greater power within a medium transmission distance.This paper focuses on the topic of matching networks in low-power wireless power transmission systems based on magnetic resonant wireless power transfer technology,and studies both theoretically and experimentally.The main accomplishments are as follows:First,introduce the research status of three kinds of wireless power transfer technologies and magnetic resonant wireless power transfer technologies at home and abroad;Second,the commonly used analytical methods of magnetic resonant wireless power transfer systems are studied: coupled mode theory and equivalent circuit theory;Third,analyze the transmitter coil and receiver coil for important factors of the wireless power transfer system,and find that the transmission efficiency of the coil is related to the coil’s material,size,line spacing,number of coil turns,etc.,and thus the design method of the coil is proposed;Fourth,the characteristics of various matching networks are analyzed through the equivalent circuit method,and the applicable range of different matching networks is obtained through the simulation analysis of Matlab.Fifth,through the previous study and research,a set of magnetic resonance wireless power transfer systems was designed.Through experimental testing,the system’s matching network was optimized.When there are external factors affecting thesystem’s transmission efficiency,the dynamic adjustment of the matching network is done.