Research On Electric Bicycle Wireless Charging System

With the advantages of time-saving,labor-saving and green environmental protection,e-bike has become an important means of transportation for People’s Daily travel.The existing wired charging mode of e-bike is bound by cables,so its application is not flexible enough,and there are safety problems such as aging cables and poor contact of plugs.Wireless charging technology has the characteristics of non-contact,good security,high flexibility and convenience,which is the development direction of future charging technology.Aiming at the charging problem of e-bikes,this paper studies a wireless charging system with the function of centralized wireless charging management,so as to solve the problem of centralized and convenient wireless charging in a large number of electric vehicle charging occasions such as express delivery,delivery,or Shared e-bikes.Based on wireless charging technology research status at home and abroad on the basis of full understanding of the charging power of the electric bicycle,the size of the structure,analysis of the characteristics of the transmission distance and so on,puts forward the suitable for electric bicycle high-frequency magnetic coupling resonant frequency,power and distance of the wireless charging system is the choice of parameters,such as the basis,on this basis,this paper carried on the thorough analysis of the technology.Wireless charging transceiver system for electric bicycle,has carried on the detailed design,mainly includes: two coil series-series transmission scheme,a half-bridge inverter of main circuit,drive control scheme of isolation amplifier,auxiliary power supply of single pipe flyback solutions,high frequency full-wave rectifier scheme,based on the receiving end of the flyback charging control and power circuit scheme,on the basis of the scheme,the design of each part of the circuit principle diagram,analyze the circuit principle and main parameters,selection of key parts according to the design index.Then,combined with the application requirements of electric bicycles,which is suitable for electric bicycle design rounded rectangle transceiver coil,and by using ANSYS finite element simulation software for simulation,Maxwell in eddy current field to obtain the magnetic field distribution and coil parameters obtained in the transient field magnetic field distribution in the process of transmission,the dynamic change process of current,voltage,verify the feasibility of sending and receiving coils.Finally,the actual production of each part of the hardware circuit,the completion of the construction of the experimental platform,the transceiver system debugging.Aiming at the wireless charging centralized management system,this paper introduces its overall structure,including three layers: charging position monitoring,charging station monitoring and upper computer monitoring.On the basis of the scheme,STM32 and STC8A8 K single-chip microcomputer are respectively used as the control core of the charging station and charging level control system,and the hardware circuits of its peripheral devices such as communication,sensor and display are designed.According to the characteristics of the monitoring system structure,design a set of special communication protocol,ensure all nodes at all levels,the transmission of data between specification,and then build the upper machine,charging stations and charging a three monitoring platform of software running state machine,under state machine,write a PC program based on LabVIEW,charging and charging station control based on single chip microcomputer C language program.The experiment finally produced a wireless charging system with the coil size of 25*35cm,which is very suitable to be installed on the e-bike.The test shows that the wireless charging system can achieve power transmission of about 180 W at a distance of 10 cm,and the transmission efficiency can reach 67%.At the same time,the monitoring system can realize remote monitoring of power device temperature,resonant voltage,resonant current and other parameters in the process of wireless charging,as well as necessary management of nodes.