Research On Wireless Power Transfer System Based On Magnetic Coupling Resonant

Based on the principle of magnetically coupled resonant wireless power transfer system,the paper discusses the circuit,magnetic field,loss and control strategy involved in the system in detail,and combines the simulation results of Mathcad,PSpice,Maxwell and other software to build an experimental platform and test related characteristics.The data is finally implemented to charge the model car.The main work of this paper is as follows:(1)Based on the series resonant circuit,the relationship between resonant capacitor and inductance is analyzed,and the relationship between the transmission frequency and the resonant frequency is analyzed by the quality factor Q.Further,based on the string-string(SS)type resonant circuit,the wireless power transfer system is modeled,the relationship between the transmission power and the efficiency of the system is analyzed,and the input impedance of the system is analyzed to obtain the critical load value and the system frequency splitting phenomenon.Further,PSpice simulation is used to analyze various characteristics of the DC-DC circuit,the rectification filter circuit,the inverter circuit,and the control circuit,and determine appropriate parameters.Based on the above conditions,the frequency characteristics when the load is less than the critical load value,the frequency characteristics when the load is bigger than the critical load value and the load end variation characteristics are analyzed.At the same time,the LabVIEW visualization interface is built for voltage and current detection to facilitate data acquisition.(2)Based on Maxwell's equations,the skin effect and proximity effect at different frequencies are analyzed,and the coupling model of square coil and circular coil is established.The variation of self-inductance,mutual inductance and coupling coefficient under different coupling distances is obtained.The spatial position and magnetic shielding effect of the coupled coil are discussed by Maxwell simulation.The methods and measures for increasing the magnetic flux and reducing the magnetic flux leakage are proposed.(3)According to the experimental requirements,select the high frequency signal,resonant capacitor,load and coupling coil,build a complete test bench,test the data of frequency characteristics,load characteristics,coil offset characteristics and shielding characteristics.Then,compare test results with simulation results.Finally,the wireless power transfer system was mounted on the model car for simple performance experiments.