Analysis And Research On Wireless Power Transmission System Based On Magnetically Coupled Resonance

With the rapid development of Mobile-Internet, mobile phones, tablet PCs and other mobile terminal are increasingly to be an integral part of people’s lives. "Power lines" becomes the last trouble to people to use the power. Under this background, many researchers studied on wireless power transmission. Power wireless transmission based on coupled resonance is one of the hotspots in the field of research and application.Technology of wireless power transmission based on coupled resonance can be called as medium-distance wireless power transmission technology, which would achieve energy efficient transmission by magnetic coupled resonance through primary and secondary coil. Compared to traditional wired power transmission technology, this technology has more advantages in many aspects such as security, efficient, user-friendly and so on. Compared to Inductively Coupled Power Transfer technology, it carry out the energy transfer by magnetic resonance methods, which greatly improve the transmission efficiency and break the limitation of short-distance transmission. Compared to the microwave radiation pattern, it can break through non-metallic materials, which greatly expand the application field of this technology.Based on the research and analysis of coupled resonant wireless power transmission technology, experiment platform of coupled resonant wireless power transmission is built and relevant experimental analysis is also made. Details are as follows:Firstly, theoretical foundation of wireless power transmission technology based on coupled resonance is introduced and the system is modeled and analyzed by coupled-mode theory and the equivalent inductance circuit. Then coupling coefficient of the system is simulated by PSPICE, with drawing the conclusion that the changes of coupling coefficient have a crucial impact on the efficiency of the power transmission system.Secondly, four capacitance compensation topology are analyzed and simulated, which give the calculation expression of the transmitted power and efficiency. The relationship among the parameters of coupling coefficient, transmitted distance, load size and system gain of voltage and current are educed. The impact on the power and efficiency of the transmission system is analyzed in this part. After that the calculating formula model on resonance is provided.Thirdly, diagrams and the main aspects of system about coupled resonant wireless power transmission are described. General schematic of transmitting and receiving circuits are given by the analysis. Magnetic field of coupling coil is simulated by Maxwell and flat spiral coil is chosen as the primary and secondary windings.Hardware circuits, related experimental analysis, and performance testing are provided in this thesis. Wireless charging of phone with 4.3V,20cm outside is achieved. Since the working experimental circuit is stable and simple, the system realizes miniaturization requirements and basically achieved the level of practical application.