Research On Wireless Power Transmission System Via Magnetically Coupled Resonance

Wireless power transmission system via magnetically coupled resonance achieves wireless power transfer within the non-radiation near-field electromagnetic field by using coupled magnetic resonance between the resonant circuits of transmitting and receiving parts.This kind of wireless power transmission has characteristics of higher transmission efficiency and power in medium distance,as well as good practical value.In this dissertation,the circuit models of four-coil and three-coil magnetically coupled resonance wireless power transmission system are studied.Then,the power conversion and signal control parts of the three-coil magnetically coupled resonance wireless power transmission system are designed,including hardware and software design.In aspect of frequency tracking part,the resonant current limiting mode is achieved by software design.The main contents are as follows:Firstly,the basic principles of the magnetically coupled resonance wireless power transmission system are analyzed.The circuit models of four-coil and three-coil system are established using circuit mutual inductance theory,and the influence of the quality factor on power transmission efficiency is studied.The frequency tracking part of three-coil system is studied,and the frequency tracking part with resonant current limiting mode is proposed.Secondly,the power conversion parts of three-coil system are designed,including asymmetric half-bridge power amplifier,resonant inductor coils and resonant capacitors.Then,the hardware and software design of signal control part for three-coil system are completed.The hardware part is responsible for the sampling and conditioning the signals of resonant circuit,and the software part is responsible for realizing the frequency tracking part with resonant current limiting mode by sampling output signals of hardware part.Finally,the prototype of three-coil system is built based on the design of hardware part.The theoretical analysis and design are validated by experimental test of prototype.The frequency tracking part with resonant current limiting mode is realized by software design,and wireless power transfer is achieved.