Research On Frequency Characteristic Of Series-Parallel System Of Wireless Power Transmission Via Magnetic Coupling Resonance

With the widespread use of electricity, it brings great convenience to human life,but the traditional contact power transmission method has the problem of contact loss, line aging,discharge and other problems which can bring potential safety hazard. And in some special occasions , it is not suitable to use the traditional wired power supply method. Therefore,wireless power transmission (WPT) has attracted people's attention.This article chooses magnetic resonance coupling WPT to study. Besides,the full bridge topology is chosen as high frequency inverter circuit. In addition, the series-parallel resonance compensation network is selected as the research object.Frequency splitting phenomenon occurs in the series-parallel system of magnetic resonance coupling WPT , which can reduce the transmission power of the system at the natural resonant point, so it is very important to research on frequency splitting phenomenon.Besides, people have different ideas on whether the frequency splitting phenomenon is same as frequency bifurcation phenomenon, the frequency bifurcation phenomenon is necessary to study as well. At present, the study of frequency splitting is more common in the series-series compensation structure. Meanwhile,as frequency splitting happens, people used to reduce the mutual inductance or to track the splitting frequencies to enhance the transmission power.However,the drawbacks of these two methods and the scope of the application of these two methods are rarely mentioned.To solve the above problems, the magnetic resonance coupling WPT series-parallel system is modeled and analyzed in this paper firstly .What's more, the factors that influence the efficiency and transmission power are analyzed and the parameters of the system are selected.Secondly, the characteristic of frequency splitting and frequency bifurcation are researched and the question whether the relationship between them is proved here.Then, the factors that influence frequency splitting are analyzed. In addition, the influences on the quality factor of the resonant circuit and the working state of the inverter caused by frequency splitting are analyzed and the measures to deal with frequency splitting in different occasions are summarized.Finally, the simulation model is established in PSIM and Pspice to verify the validity of the theoretical analysis, and the experimental platform is designed to verify the theoretical analysis and simulation.