| When the resonant coil of the wireless power transmission system is placed non-coaxially,the transmission efficiency of the system will decrease.At pr esent,scholars at home and abroad mostly focus on the study of the offset characteristics of non-coaxial circular spiral coils,and few studies on rectangular spiral coils.The magnetic resonance coupled wireless energy transmission system uses high-frequency magnetic fields for energy transmission.The high-frequency magnetic fields will generate strong electromagnetic radiation and negatively affect the electromagnetic safety of the surrounding environment.In view of the above problems,this paper will use the magnetic resonance coupled wireless power transmission system composed of rectangular spiral coils as the research object to conduct the offset characteristic analysis and electromagnetic compatibility design.First,this paper analyzes the structu ral characteristics of several common magnetic resonance coupling coils,studies the effects of coil shape,lateral displacement and turns on the coupling performance,compares the spatial magnetic field distribution of coils of different shapes,and summarizes the application of coils of different shapes.Then,the coupling model of the non-coaxial rectangular spiral coil is established,and a method for calculating the mutual inductance through the coordinates of the vertex of the rectangular coil is proposed.On this basis,the effects of different types of displacement offset and angle offset on the coupling performance and the regular pattern of the mutual inductance of the coil under the effect of the two offsets at the same time are studied.The simulation results show that the lateral offset has greater influence on the mutual inductance than the longitudinal offset,and the flip angle has a greater influence on the mutual inductance than the deflection angle.Next,a three-dimensional model of a shielded wireless power transmission system with a rectangular spiral coil as the resonant coil is established,and the effects of the type of metal shield,the method of adding the shield and the distance between the shield and the coil on the electrical parameters and transmission performance of the system are investigated.The relationship between transmission efficiency and output power changes with frequency is explored.Taking the system with shields at both of the two coils as the research object,the movement of the operating point of the maximum transmission efficiency and the maximum output power based on the matched load of the system after the shielding is observed.Finally,the shielding effects of different metals on the magnetic flux leakage in th e vertical and horizontal directions of the system are compared.The simulation results show that the electrical shielding effect in the vertical direction is better than the magnetic shielding effect,and the shielding effect in the horizontal direction both shows poor,so a combined shielding scheme is proposed,and the relevant parameters of the combined shielding are optimized.Through the analysis of the offset characteristics and electromagnetic compatibility design of the magnetic resonance coupling wireless power transmission system composed of rectangular spiral coils,the regular pattern of the coil coupling performance under different offsets is obtained,the effect of the metal shield on the system parameters and transmission performance is analyzed,and the influence of the system on the external electromagnetic environment is studied,which provides a theoretical basis for the electromagnetic compatibility and safety design of wireless energy transmission systems. |
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