The Research And Design On High Frequency Power Of Magnetic Resonance Co Upling Wirless Power Transfer

Magnetic resonance coupling wireless power transfer has become the research focus at home and abroad,after being proposed as a new kind of non-contact power supply technology.Many scholars have been studied deeply on MCR-WPT about the principle of transfer,the structure of circuit,the design of coil,the characteristic of transmission,etc.But less on the high frequency power of the system which have a great influence on efficiency and performance of MCR-WPT.Recently the front high frequency power is composed by information generator and power amplifier,and the frequency of output power is about 2MHz?30MHz?which can meet the research on system characteristics in MHz level,however,the frequency is too high may cause uncertainty effects on the surrounding biological,meanwhile,there is a big resistance,which affects the overall efficiency of the system and also restrict the development of large output power.In addition,there is a big problem---the system efficiency decline caused by the frequency drift---confine the MCR-WPT technology to application.This paper uses the power electronic devices to study and design on high frequency power of magnetic resonance coupling wirless power transfer.First of all,this paper choosed the coil structure transmission of MCR-WPT system as the starting point to analyze the high frequency power.Comparing the two coils structure with four coils structure on the choice of resonant circuit topology and optimize of the output power and system efficiency.Selecting the two coils structure which coils both adopted by serial resonant as the overall load of high frequency power in system through numerical simulation and combining actual application.Secondly,having designed the opening high frequency power in system of MCR-WPT with the power electronic devices,including the selected of power switch devices and the main circuit inverter,the designed of driving circuit based on IR2110S and the control circuit of hardware and software based on DSP28335.Building up the experimental platform of MCR-WPT system and completed the relate experiments of system effected by voltage duty ratio in high frequency power.Then,the MCR-WPT system detuning mechanism was studied,and when the load meet the condition ofRL>Rrnmax,the transmitter coil detuning is the main factor to cause the system efficiency decline.The phase-locked loop is introduced,and the system resonance frequency is tracked on line through collecting the phase between output voltage and current of transmitter circuit loop.It can find that system efficiency is constant if system was detuned on the condition of RL much more than the value of normalized detuning impedance.According to the principle of phase-locked loop and its linear mathematical model,setting up the simulink model of MCR-WPT system based on phase-locked loop.The system can be resonant again fast under the adjustment of phase-locked loop while the system was detuned,in addition,the system efficiency is constant when the RL meet the above conditions.Finally,completing the design of the software phase-locked loop algorithm based on DSP28335 and the relative flow chart was given,based on the design of opening high frequency power,meanwhile,completed the design on hardware of control circuit of frequency tracking.Experiments verified that the high frequency power based on frequency tracking designed by this paper can solve the energy instability caused by system detuning commendable.