Research On Wireless Charging Technology And Its Application In The Electric Vehicle Charging

Global energy crisis and environmental pollution promote the development of the electric car industry all around the world.More and more autoworkers focus on the development of the electric vehicles(EV),in this case EV industry has being develop rapidly.But limited by the characteristic of battery,the distance of electric car driving is limited,which limits the development of EV greatly.At the same time,a mass of EVs integrating into the power grid must bring certain impact to the stability of power grid operation.So it is necessary to study the charging system of electric vehicle to meet the requirement of the EVs meanwhile maintaining the normal work of the traditional power grid.The traditional charging device work with the cable,which is completed the work via charging pile.But charging pile takes up a lot of land and one charging pile can only charging for one EV,when the quantity of EVs is large,this kind of charging system will difficult to meet the charging requirement.This paper analyzes the principle of wireless power transmission technology and the characteristic of battery and chooses suitable wireless charging approach for charging system.In the end of this paper,a kind of wireless charging system is been designed.(1)Analyzing the principle of three kind of wireless power transmission technologies(WPT).Introduce the principle of the electromagnetic coupling wireless transmission technology,resonance wireless transmission technology and radio wireless transmission technology principle.Building circuit models of these WPTs and expressing the transmission efficiency and output power with mathematical expression according the models.Comparing these charging technologies in three aspects.(2)Researching on the on-board battery model and building the model of battery using MATLAB,then studying the charge and discharge characteristics.Stating the demands for four kinds of EVs,and analyzed the feasibility and value of applying the wireless electric power transmission for the electric vehicle charging system.(3)Combined with practical application,proposing the requirements of the wireless charging system for electric vehicle.Proposing the wireless charging system architecture which is consists of electricity pretreatment,sending,receiving,charging and battery five modules.Analyzing the requirements of the various modules and selecting the appropriate circuit structure,showing the topology of static wireless charging system.Besides,combining with the demand of highway wireless charging system,proposing the dynamic wireless charging system framework and the working process.