Research On Power Orientation Strategy Of Wireless Power Transfer System

With the development of the power industry,Wireless Power Transfer(WPT)technology has also been widely used.Magnetically coupled resonant wireless power transfer(MCR-WPT)technology has high transmission efficiency,safety and reliability,and is free from wire constraints.Since then,in order to be applicable to various scenarios and improve charging flexibility,various topologies for energy transfer and corresponding control methods have been proposed.This paper focuses on the problem of low transmission power caused by the incomplete alignment of the transceiver coils in the magnetic coupling resonant wireless power transmission technology,and proposes a method to achieve power orientation through a phased coil array.Aiming at the uniform distribution of the planar magnetic field,the structure of the array coil is designed,and according to the position of the receiving coil,the magnetic flux in the designated area is maximized by controlling the phase of a single coil in the array.At the same time,a BP neural network fitting regression method is proposed to determine the phase difference between each coil in the array when the transmission performance is optimal,and the phase control and output monitoring system of the array coil wireless power transmission system is designed.Firstly,the basic principle of wireless power transmission is briefly introduced;according to the magnetic field distribution theory generated by space current-carrying direct wire and space closed curve in space,the space magnetic field theory is deduced for circular and square coils,and an array is formed by a single coil.The spatial magnetic field distribution of the array coil formed by the shape is theoretically deduced.Secondly,according to the distribution of the magnetic field generated by the coils on the specified plane and the coupling between the coils,the type of a single coil that constitutes the array coil is selected;with the specified magnetic field uniformity as the goal,a nonlinear planning is performed to determine the magnetic field in the plane area.The coil turn spacing in the case of the best uniformity;deduce the magnetic field distribution and magnetic flux when the coil array composed of the coil has a phase difference between the coils,and use the BP neural network to compare the phase difference,the regional center coordinates and the region Perform regression fitting on the relationship between the magnitude of the magnetic flux and train the model;design the array wireless power transmission system,and make the corresponding theoretical derivation.Then,according to the above theoretical analysis and optimization results of the array coil,the corresponding phase control,signal acquisition,communication and the design of the host computer algorithm are carried out to realize the phase control and output current acquisition of the array coil,and can be determined by the host computer.The optimal phase difference at the current receiver coil position.Finally,simulation and experimental verification are carried out to simulate and verify the magnetic field distribution and magnetic flux in the plane area selected by the non-equidistant coil and the array coil formed.The experimental platform for the coil array and phase control system is completed.When there is a specified phase difference between each coil,it is verified with the transmission power,and the phase control and monitoring display functions of the host computer are verified.