Research On Coupling Of Wireless Charging System Of Electric Vehicle And Design Of Coil

In the field of transportation,electric vehicle,driven by clean energy,have improved energy efficiency and reduced waste emissions and pollution.In recent years,electric vehicles have been strongly supported by national preferential policies and favored by the market,and have developed rapidly.At present,electric vehicles generally use the traditional way of power transmission by wire or cable to charge.Because of the problems of wear,aging,electric spark,inconvenient carrying and so on,it is difficult to meet the needs of people's production and life.However,Wireless power transfer technology has attracted more and more attention because of its incomparable advantages such as no electrical connection and flexible and safe power supply.The development of Wireless power transfer technology can effectively promote the large-scale popularization and application of electric vehicles and the diversification of transportation energy structure.To improve the transmission efficiency and stability of the wireless charging system for electric vehicles,this paper analyzes and optimizes the coupling coil and each part of the system based on wireless power transfer theory.And the wireless charging system is in the well efficiency.Firstly,this paper introduces the types of wireless power transfer and its development at home and abroad.Comparing the characteristics of various types,we take magnetic coupling resonant wireless power transfer as research object.Four elementary resonant topologies are introduced,and we do research on wireless charging system with series-series resonance about mechanism and characteristics by using mutual inductance model.The influence of the coil's internal resistance and mutual inductance as well as the load on system is analyzed theoretically.Then,the electromagnetic coupling structure of system is studied.This paper analyzes the influence of the structure design of planar spiral coil on its physical parameters and performance.And coil's internal resistance,self-inductance and mutual inductance are calculated.To improve the performance of the system,we design the structure parameters of coil by optimizing its radius,turns and line spacing.The working process of wireless charging system is introduced in detail.Each part of the system,like Bridge Rectifier,high-frequency inverse transforming circuit,Buck Chopper and so on,is analyzed and picked,so as to finish the design of system.Finally,the simulation software MATLAB is used to build circuit simulation model of the magnetic coupling resonant electric vehicle,which can charge in constant current and constant voltage based on Buck Chopper.Charging simulation validates the analysis and provides theoretical support for the design of wireless charging system.