Research And Design Of Wireless Energy Transfer Technology For Mobile Devices

Wireless Power Transmission(WPT),as a new way of power transmission,effectively avoids the potential safety hazards of traditional wired charging.But for electric vehicles,the fixed-point wireless charging still can not solve the problems of short range and frequent charging times.However,the dynamic wireless power transmission technology can not only greatly improve the range of electric vehicles,but also reduce the load of on-board batteries,thus decreasing the weight of the vehicle.This paper will be based on the study of wireless power transmission of mobile devices,to explore the design method which has universal applicability in dynamic WPT system and can effectively reduce the blindness of design.Firstly,the transmission model of multiple transmitting coils in parallel is analyzed in this paper according to introduce the principle and system structure of dynamic WPT technology.On this basis,several factors affecting the performance of the coupling mechanism are studied in depth.The writer calculates the mutual inductance between the emitter coil and the receiver coil by using Neumann Formula with comparing the influence of the mutual inductance between the coils with different structures when the receiving coil is transversely offset.It was concluded that the influence of the mutual inductance between the square coil and the emitter coil is the smallest when the square coil is offset,and then to choose the distance between transmitting coils reasonably based on analyzing the influence from the mutual inductance between the transmitting coil and the receiving coil on the transmission performance.With the help of Ansoft MAXWELL simulation software,the influence of current phase and winding mode of adjacent parallel transmitting coils on coupling performance is studied.The result is that the performance of the coupling mechanism is the best when the coils are winded in a compact way and the current phase of adj acent parallel transmitting coils is the same.For the dynamic WPT of electric vehicle,it is so difficult to ensure real-time and effective signal transmission between the vehicle receiver and transmitter.In addition,when multiple loads are received at the same time,the transmitter controller can not control the output of each load separately at the same time.In this paper,the method of independent control of transmitter and receiver is proposed.The state space averaging method is used to model and analyze the transmitter and receiver circuits respectively.The effectiveness of the control method is verified by simulation in MATLAB/Simulink.Finally,the author measured the current of the radiation coil,the output voltage of the rectifier at the receiving end and the charging current of the battery during the movement of the receiving coil through the experimental platform,which proved the effectiveness of the optimization design and control method of the coupling mechanism.