Design And Application Of Magnetic Negative Metamaterials In Magnetically Coupled Resonant Wireless Power Transfer Systems

With the development of technology,the use of wire transmission has become the final form of traditional technology.To promote the development of technology,it is necessary to open up new transmission forms.Therefore,wireless energy transmission technology has become a current research hotspot.However,the current research mainly focuses on power electronic transformation and topology structure,and the research is relatively mature.Therefore,to improve the transmission efficiency of wireless power transmission technology,other research directions are needed.In this thesis,a magnetically coupled resonant wireless power transfer system with a target frequency of 6.78 MHz is designed,and a magnetically negative metamaterial is added between the coupled coils to study its effect on the system’s transmission performance.The main research contents of this thesis include:（1）Establish the theoretical framework of metamaterials,divide the electromagnetic wave medium into four quadrants with the help of constitutive parameters（dielectric constant and permeability μ）.Based on Maxwell’s equations theoretical derivation of the negative refraction effect of metamaterials is conducted,and introduce effective permeability The two calculation methods are numeri calculation and S-parameter inversion method.（2）The HFSS simulation software is used to establish the model of the magnetic negative metamaterial resonant unit,the excitation source is set by the Floquet port method and the wave port method,and boundary conditions are established around it to simulate the magnetic negative metamaterial’s reflection on the magnetic field,and the S parameters of the metamaterial are obtained.,write a program to calculate the effective permeability of magnetic negative metamaterials in Matlab,and use the numerical method and the S-parameter inversion method to draw the image of the effective permeability to test the accuracy of the model.（3）The high-frequency power source of WPT system is designed.The circuit model of class E power amplifier is established in LTSpice,and the parameters are adjusted to obtain the target output power.The hardware design is carried out on FR4 substrate to detect whether the switch tube can produce ZVS soft switch,and the performance of e-type power amplifier under different voltage conditions is tested.（4）A coupled coil model is established in HFSS,and the impedance of the model is obtained by the wave port method.The Smith circle is used to complete the impedance matching in the ADS software to obtain the compensation capacitance of the single coil;the compensation capacitance of the matching network is added to the coupled coil model to simulate the MCR WPT system,adjust its value until the coupling coil resonates at the target frequency.（5）An experimental platform of the WPT system was built to compare the changes of the system before and after adding the magnetic negative metamaterial,and at the same time,the transmission distance of the coupling coil was changed to study its influence on the transmission efficiency of the system,and to analyze the role of the magnetic negative metamaterial in the WPT system.