Synchronization Strategy Of Adjacent Rails Excitation Current In Dynamic Charging Mode Of Electric Vehicle

In recent years,the development of electric vehicles is in full swing,becoming the main force of new energy vehicles in the future.However,the battery endurance still needs to be improved.Many measures have been taken to improve the battery endurance of electric vehicles,such as replaceable batteries,charging piles and so on.As the main branch of wireless charging technology,Magnetic Coupling Wireless Power Transfer(MC-WPT)has the advantages of high transmission efficiency,large transmission power,long transmission distance,flexible location between receiving equipment and power supply without cable,and is very suitable for solving the problem of insufficient endurance of electric vehicles.Wireless charging for electric vehicles can be divided into static wireless charging and dynamic wireless charging(DWC).The static wireless charging technology has the same problems as the wired charging pile technology,such as frequent charging,long charging time,short duration,large battery volume,etc.Therefore,DWC technology will become the key to solve the charging problem of electric vehicles in the future,which will be used to improve the problems of static and wired charging methods.At present,it has become the main research hotspot of many scholars and research teams at home and abroad.The research results have been extended to some engineering fields,and some solutions have been put forward for the current electric vehicle charging field.However,with the deepening of research and application,some key problems need to be solved urgently.Current synchronization when the rail is switched is one of them.The aim of this paper is to give a synchronization strategy which can be realized independently,research work has been carried out on this issue.Firstly,the structure and principle of the system are briefly introduced from the aspects of energy conversion topology,resonance compensation network,magnetic coupling mechanism and position detection device.The common methods of current synchronization between adjacent guideways are analyzed.By comparing several different methods,the necessity and advantages of current synchronization between adjacent guideways using electromagnetic induction between rails are expounded.A steady-state mathematical model of single-rail charging and double-rail charging is established by AC impedance method.The mathematical expressions of electric energy transmission and the induced current of the guide are given.The relationship between the induced current and the mutual inductance values of the guide coil and pick-up coil is analyzed.Finally,a constraint condition of synchronous control strategy of the guide current using the induced current is given.Based on the parameter design method of the partial resonant element,the selection of some key hardware devices and the flow chart of the control strategy are given.The simulation model of the system is built by MATLAB/Simulink.The expression of induced current and the effect of current synchronization of adjacent rails and verified.The experimental device is built to verify the theoretical model and synchronization strategy.