A Research Of Three-dimensional Wireless Power Transfer System Based On Sparse Cavity

With the advent of the Internet of Things(Io T)era,the distributed sensor can be used to achieve intelligent control of equipment,which greatly enriches and facilitates people’s lives.However,how to ensure large number of distributed sensors indoors with the longterm and stable energy supply is the key to realize the Io T.In recent years,a cavity resonance wireless power transfer(CR-WPT)has emerged,which generates magnetic field by exciting the metallic cavity,and then transfers power through the magnetic field couple with the receiver.Compared with other WPT methods,CR-WPT technology can transmit high power to long distance with high power transfer efficiency and safety,which is very suitable to provides stable energy support for small receiving devices in indoors environment under Io T era.However,the cavities used in CR-WPT are mostly composed of fully enclosed metallic walls or dense metallic meshes,which are costly and block communication signals.On this basis,the CR-WPT system based on the sparse cavity is researched,and the sparse cavity construction methods suitable for CR-WPT system are designed by electromagnetic theory.At the same time,the simulation model and experimental system are constructed to analyze key indicators such as power transfer effect,communication performance and security.Compared with the traditional CR-WPT,this system has a lower cost and wireless communication signals can pass through the cavity without blocking,which will have more practical application prospects in the future.The main research contents of this paper are summarized as follows:First,the research background and significance of CR-WPT are introduced,and the power transfer mechanism and working principle of the CR-WPT system are analyzed.Based on coupled mode theory and circuit theory,the coupling coefficient and power transfer efficiency prediction formulas are derived,which provide theoretical research ideas for the subsequent design of the sparse cavity.Then,according to electromagnetic theory,the sparse cavity designed methods suitable for two types of CR-WPT system structure are obtained,and the theory and fullwave simulation model are established for verification.Through simulation optimization,the optimal sparse cavity parameters are determined,which provides a plan for the establishment of the experimental system;Finally,according to the simulation model,the CR-WPT experimental system based on the sparse cavity is constructed to verify the power transfer effect of this system.At the same time,simulations and experiments have been used to prove that the system can safely and efficiently transmit power to receiver inside the cavity,while the cavity structure will not block wireless communication signals pass through.