| With the continuous development of wireless power transmission(WPT)technology,it gradually becomes the research hot spot all over the world recently.As a new direction of the development of WPT technology,magnetic resonance coupling WPT has their unique characteristics of realizing long-distance power transmission,high efficiency,tiny radiation and weak effect of non-magnetic objects on the system.Magnetic resonance coupling WPT technology has wide application prospects and is normally used in the portable electronic equipment,Smart Home,electric vehicles as well as rail transportation.In previous work,magnetic resonance coupling WPT has been preliminary analyzed and got some available results in some ways,however,there is still many blind zone,E.g.,the electromagnetic analysis and optimization design of the magnetic resonance coupling wireless power transmission system in the movable circumstances.The above problem is just discussed in this thesis,and the design of magnetic coupling coil directly affects the performance of WPT,which is the core part of this research.When it comes to the electric vehicle,the structure and power transmission process of the magnetically coupled resonant WPT system are first analyzed.Based on the theory of mutual inductance model,the equivalent circuit model is established,and the electromagnetic analysis is carried out by Maxwell simulation as well.Finally,the optimized design of the coil is demonstrated to improve the efficiency,enhance the anti-offset capability and reduce the system radiation.The main work of this thesis is as follows:(1)Based on the theory model of mutual inductance,the WPT process is analyzed,and the series-series resonant compensation structure is analyzed and compared,and the system equivalent circuit model is established.On this basis,the selected coil basic properties of power efficiency characteristic,frequency characteristic,distance characteristic and direction characteristic are further analyzed.(2)The targets of optimization design of the coupling coil are to improve the transmission efficiency of the system,enhance the anti-offset ability and reduce the radiation.Based on the existing model,the parameters such as efficiency are calculated by Matlab software,and the coil parameters are optimized.For structure optimization,the rectangular plane helical structure with high ability of anti-offset is selected as the coupling coil structure,and the plane iron core structure is introduced to increase the coupling coefficient.(3)By utilizing the Maxwell simulation software,the electromagnetic properties of coupling coil which is used in wireless energy transmission process is simulated and analyzed.Therefore,the optimal transmission distance,the position of coils and the position of the plane iron core are obtained.(4)The coupling coil is wound and the experimental platform is built according to the parameters of coupling coil solid model which is used the optimized parameters.From the experimental results of the optimized coupling coil,the system transmission efficiency and anti-offset capacity is increased by 12%and 57.6%,respectively.The content of this thesis not only includes the electromagnetic distribution of the magnetically resonant coupling WPT system in the movable circumstances,but the optimization design of the magnetic coupling coil.The result of this thesis gives a good reference to solve the problem of efficiency degradation caused by the position drifting in the wireless charging process.In addition,it sets up the theoretical foundation of the application of portable electronic products and electric vehicle wireless charging. |
PDF Full Text Request