Scheme And Circuit Realization Of Wireless Power Transfer Based On Magnetically-coupled Resonant

As a mid-range wireless power transfer technology, Magnetically-coupledresonant wireless power transfer (MCR-WPT) technology can be achieved withhigher transmission efficiency, which has longer transmission distance compared withthe magnetic inductive coupling WPT technology，and smaller radiation to people orbiological compared with radiational wireless power transfer technology. Therefore, ithas become the common focus of both academia and industry ever since the researchfindings were published by Massachusetts Institute of Technology (MIT) in2007.This dissertation includes the following works:(1) Three theory analysis methods of Magnetically-coupled resonant wirelesspower transfer system are introduced—coupled mode theory, circuit theory and filtertheory. Then the condition of the maximum power transfer is deduced through thecircuit modeling, and the illustration is given when the system is extended to multipleresonant coil case.(2)Through numerical simulation method, the factors which affect thetransmission performance of MCR-WPT are studied.(3) Based on circuit theory，the WPT system with an intermediate coil resonatorwhich can improve the transmission distance is studied, and the condition of criticalcoupling and the maximum power transmission are deduced. By analyzing andmodeling of MCR-WPT system with one single supply to dual-load, the condition ofpower distribution and the maximum power transmission are given. The influence ofcross coupling between the non-adjacent coils effect on the transmissionperformance of the system is studied in detail. Then a method of adding reactance tocompensate for the cross coupling effect in the circuit is proposed and the simulationand experimental results have proved its feasibility.(4) According to the experiment requirement, an MCR-WPT system is designed.From the overall framework of the system, the selection of driving chip and thepower switch tube in the process of high frequency inverter circuit are introduced.Then an experimental platform for experiment is built according to the design of thecircuit and a small bulb with specifications of2.5V/0.3A is successfully lit.