Research On Wireless Power Trasfer System With Multiple Transmitter Coils

With the wide application of electronic equipment,wireless power transfer technology plays a more and more important role in people’s life.However,the existing single transmitter and single receiver wireless power transfer system has limited application scenarios and can not meet people’s actual needs.Due to the random change of receiver position,there is the problem of coil offset and dislocation in the actual operation.The dislocation exceeds a certain range,the transmission efficiency decreases rapidly.Therefore,in order to obtain a wider charging range and more flexible wireless power transfer system,this topic studies the energy beamforming of multiple transmitters wireless power transfer system and the optimal design of transmitter array,and puts forward a design scheme of wireless power transfer system with high robustness and high transmission efficiency under the position offset of receiving equipment.The main research contents of this paper are as follows:(1)The mutual inductance theory is used to model the single transmitter and single receiver system,and the operating frequency,transmission distance,radial offset distance,angular deflection are analyzed through the finite element multi physical simulation software to study the influence on the transmission characteristics of the system.The mutual inductance,resonant capacitance,coupling coefficient,quality factor and other factors of the coupling coil structure are studied,and then optimize the shape,structure,turns and radius of the coupling coil.(2)Analogous to the MIMO beamforming technology in the field of wireless communication,which makes multiple transmitters focus on the target receiving position by constructing a combined magnetic field,so as to improve the transmission efficiency of the system.The regulation of transmitter current in beamforming method is deduced,that is,the current of transmitter is directly proportional to mutual inductance.The boundary conditions under which the multiple transmitters system is superior to the single transmitter system are discussed.(3)In view of the influence of the internal coupling between transmitters on the transmission performance of the system,according to the relationship between the overlapping degree and mutual decoupling between transmitters,optimize and adjust the position of transmitters to reduce the internal coupling as much as possible,improve the power factor of the system,reduce the consumption of reactive power,and make the system more safe,stable and efficient.(4)In view of the problem that the loss and heating of the transmitters coil lead to the change of the system temperature in the actual work,firstly,the coil heating loss is used to optimize the coil parameters.Then,from the perspective of heat transfer,the temperature distribution in the working process of the coil is discussed,and then extended to the heating problem of the coupling structure of the multiple transmitter coils system.In this paper,through theoretical modeling and experimental verification,the superiority of the beamforming method applied to the multiple transmitter coils system is demonstrated,and the transmitter coil array is optimized from the perspective of internal coupling and array temperature field,which provides a feasible method for further research on the multiple transmitter coils system.