Research On The Topological Structure Of Magnetic Coupling Resonance Wireless Power Transfer System

Compared with traditional charging methods,wireless power transfer has the advantages of safety,reliability,flexibility,and high commercial value.It has received more and more attention and research,and has achieved a series of research results.In the magnetic coupling resonance wireless power transfer system,the compensation topology can not only make the circuit reach the resonance state,but also improve the transmission characteristics of the system.Therefore,this thesis studies the compensation topology.The main research contents are as follows:In this dissertation,three kinds of wireless power transfer methods are introduced,and the current status of research on topological structure at home and abroad,establishes four basic compensation structure mathematical models,and analyzes them with circuit theory.Two kinds of basic compensation structures are simulated and analyzed by Matlab.The results show that the series-series compensation structure and the series-parallel compensation structure have better transmission characteristics in resonant condition,but the output power of the system is lower in small load resistance condition.When the transmitting end is in series resonance,the switch tube will bear a large current stress and damage the device.For the shortcomings of the traditional basic compensation structure,this thesis adds a capacitance inductance at the transmitter and receiver to form an LCC type compensation structure based on the basic topology.The relationship between the transmission characteristics of the system and the load resistance and coupling coefficient is simulated by Matlab.The relationship between the frequency and LCC compensation structure under different load resistance and coupling coefficients is analyzed.The constant current and constant voltage characteristics of LCC circuit are analyzed by PSIM.The simulation results of the five compensation structures are compared and analyzed,and the characteristics of different composite compensation structures are obtained.The LCC-S compensation structure is selected for analysis and research in combination with the economical type and complexity of the system.According to the selected LCC-S compensation structure,the basic characteristics of load resistance,coupling coefficient,frequency splitting,soft switching,voltage gain,and coupling coil parameters are analyzed and studied,and solutions are proposed based on the existing problems.Finally,a set of static wireless power transfer device was built,and a brief introduction to the device models used by each module.The factors affecting the transmission performance of the system were verified according to the built device platform.From the experimental results,it can be concluded that improving the system parameters(load resistance,distance,frequency)can improve the transmission characteristics of the system.