Research On Optimization Of Resonant Coils For Magnetic Resonant Coupling Wireless Power Transfer

Recently,wireless power transfer technology has received considerable attention.Compared with the traditional wired power supply,the electric power in wireless power transfer is transmitted without the direct wire connection.Due to the advantages of convenience and safety,wireless power transfer has great potential in a wide range of applications,including consumer electronics,biomedical implants and electric vehicles.In the early research on wireless power transmission,inductive power transfer is investigated,which has the high transfer efficiency but short transfer distance.The transfer distance of the magnetic resonant coupling wireless power transfer is much longer than that of the inductive power transfer.So the thesis chooses the magnetic resonant coupling wireless power transfer as the research object.Extensive research has revealed that the transfer power decreases when the distance between resonant loops drops below a certain value due to frequency splitting.In order to suppress frequency splitting,frequency tracking control and impedance matching technique has commonly been used,which requires a series of complex circuits and complicates the system.In addition,the frequency splitting can be eliminated by optimizing the coil structure without the additional complex circuits.In this thesis,the transfer efficiency is enhanced by changing the configuration of the coil.This thesis builds the model of the traditional helix system and planar system respectively,analyses the influence of each parameter of the coil,and obtain the optimal parameters through simulations,which can make the mutual inductance changes gently thus the frequency splitting is suppressed and the transfer efficiency is enhanced.Experiments are conducted to validate the performance of the magnetic resonant coupling wireless power transfer system with the optimal coils.The results indicate that the proposed structure is superior to the traditional system and that it shows better performance in power transfer efficiency and transfer distance.