Research On Wireless Power Transfer Based On Magnetic Coupling Resonance

Magnetic coupling resonance wireless power transfer is an important branch in the field of wireless power transfer.At present,scholars at home and abroad have done a lot of work on the key issues and market promotion of magnetic coupling resonance wireless power transfer system,and achieved fruitful research results.However,there are still some problems to be solved,such as composite topology and ferrite shielding technology.Based on these problems,this thesis conducts in-depth research,and its main research contents are as follows:(1)Based on circuit theory and mutual inductance coupling theory,this thesis establishes three typical mathematical models of magnetic coupling resonance wireless power transfer system(series-series compensation,LCC-parallel compensation and LCL-series compensation).The relationship between transmission characteristics of the three systems and load resistance,coupling coefficient and frequency is analyzed by using MATLAB software,and the correspondin g three-dimensional relationship diagram is drawn.Furthermore,the constant current characteristics of LCC-parallel compensation system and the constant voltage characteristics of LCL-series compensation system are verified by PSIM software.The simulation results show that the introduction of LCC-parallel compensation and LCL-series compensation composite topology can effectively overcome the shortcomings of series-series compensation system,such as poor no-load characteristics and easy damage to equipment.(2)Five basic characteristics of series-series compensated wireless power transfer system(frequency,distance,coil parameters,resonance and load)are studied by combining theoretical calculation,simulation analysis and experimental verification.Through analysis,it is concluded that frequency and load will have an impact on the system,that is,small size coils are selected under the condition of small distance,while coil size should be increased at long distance.Subsequently,the magnetic circuit characteristics and frequency characteristics of series-series compensation system are analyzed by Maxwell and Simpler solver in ANSYS finite element software,and the effects of different coverage area,shape and distance from ferrite shielding material to coil on the system are emphatically analyzed.The experimental results show that the introduction of ferrite shielding material will change the coupling coefficient,quality factor and coil resistance of the system,and then affect the transmission characteristics of the system.(3)The module circuits of the magnetic coupling resonance wireless power transfer system are analyzed in detail,including device selection and hardware circuit design,and a set of static wireless power transfer device and a dynamic wireless power transfer device are built respectively.Finally,the influence of distance,load resistance and ferrite shielding material on the system is analyzed by using the static device.The experimental results show that the transmission performance of the system can be improved and the leakage of magnetic field can be reduced by optimizing system parameters(distance,coil parameters,etc.)and adding ferrite shielding materials.