| In this paper,a magnetic resonance coupled wireless energy transmission system with a working frequency of 13.56 MHz is designed to solve the problem of flexible wearable electronic energy supply and space compactness.Using a combination of modular design and global design,the requirements for impedance matching in the entire system are taken into account when finely designing each module to reduce the system energy loss,thereby improving the energy transmission efficiency of the entire system.Through theoretical calculations and simulation optimization,a prototype device with a compact,efficient,safe,and portable device for wireless charging of flexible wearable electronics was fabricated.The main research content can be summarized as follows:(1)Using Coupled Mode and Equivalent Circuit Theory to Analyze the Transmission Mechanism of Magnetically Coupled Wireless Power Transfer Technology.(2)Using a combination of modular design and global design,a modular design of a 13.56 MHz magnetically coupled resonant wireless energy transmission system was performed.Detailed theoretical analysis and calculation are performed for each module to obtain the efficiency expression and system efficiency expression of each part.And analyze the relevant parameters,such as system input voltage,coil quality factor,coupling coefficient and load value,etc.on the system efficiency.(3)The ADS(Advanced Design System)software is used for circuit simulation analysis of the high-frequency inverter module,including transistor characteristic analysis and stability analysis,basic circuit parameter design and optimization,source pull-in and load pull-in design,and matching circuit design.The harmonic balance method was used to simulate the performance of the entire high-frequency inverter circuit.The simulation results show that the output performance of the designed E-type rectifier high-frequency inverter circuit is good,and the output indicators meet the design requirements.(4)Using Ansoft Maxwell to analyze the relationship between the coupling coefficient,mutual inductance and transmission distance of the coupled coils,the magnetic field distribution between the coupled coils at different transmission distances was obtained.The coupled-coil resonant circuit is simulated using ADS.The simulation results show that the designed coupled system has low return loss and high transmission efficiency.(5)Using ADS to analyze the characteristics of Class E rectifiers,the simulation obtained the input current and voltage waveform in accordance with the theory.The simulation results show that the stable voltage and current waveforms are output after the class E rectifier,and the waveform consistency is very good.(6)The effect of the magnetic composite film on the performance of a single coil was analyzed theoretically and experimentally,providing theoretical and practical support for the magnetic composite film integrated into the 13.56 MHz magnetically coupled resonant wireless energy transmission system designed in this paper.(7)The system prototype device was fabricated and the entire system device was analyzed experimentally.The effects of distance between coils,system DC input voltage,load and magnetic composite film on the system output voltage,output power and overall system efficiency were analyzed.The theoretical and experimental measurements of each module's efficiency and system efficiency were compared.A good match between the two verified that the theoretical analysis results and the simulation parameters were optimized enough to accurately guide the design of a real 13.56 MHz magnetically coupled resonant wireless energy transmission system.At the same time,electromagnetic security was analyzed and the system was portable.Experiments show that under a certain transmission distance,when the system input voltage is 5 V,the system can obtain 5.936 V DC output voltage and 2.349 W output power,which meets the requirements for miniaturized flexible wearable electronic wireless power supply. |
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