| With the increasingly serious environmental and energy problems brought by fuel vehicles,more and more attention have been paid to electric vehicles from all walks of life.Various countries have issued policies concerning the replacement of fuel vehicles with electric vehicles.However,the development of electric vehicles still faces many problems currently,such as large space occupied by battery pack,short mileage of battery life,large charging current in fast charging mode,charging in high frequency and long hours of single charge,small number of charging piles.What’s worse,bulky plug-in charging plugs and long-term frequent operation will cause interface aging and security risks in rainy and snowy weather.At present,the charging methods of electric vehicles include plug-in charging,static wireless charging and dynamic wireless charging.Electric vehicles can enter the static wireless charging station for charging,which solves the problems of complicated operation,aging of the joint,safety risks in rainy and snowy weather and others caused by traditional plug-in charging.However,long hours of single fully charging and driving mileage short still needs to be solved by dynamic wireless charging.Dynamic wireless charging lays an array of coils below the established route of the electric vehicle.When the electric vehicle is on this section of the road,based on the principle of electromagnetic coupling,electric energy is transmitted to the vehicle energy storage battery pack or motor in real time by the coils array buried under the road surface,so that the electric vehicle can be powered directly from the road.Accordingly,electric vehicles can carry fewer or even no energy storage batteries,prolong its endurance mileage,so as to improve the convenience and security of power supply.This paper mainly focuses on the research of dynamic wireless charging system of coil arrays,mainly including three parts.In the first part,the related theories of magnetically coupled radio energy transmission technology is analyzed,on the basis of which,the model building scheme is built,the hardware circuit design of dynamic wireless charging system and the selection of components are completed.The circuit diagram is drawn with Protel DXP software,after simulated and verified by PSIM software,the circuit board is welded,the experimental platform of coil array dynamic wireless charging system is built,and the constant power control scheme of dynamic wireless charging system under double coil coupling resonance is proposed,so as to improve the stability and efficiency of the system.In the second part,the hardware platform is tested,and the on-off control strategy of the coil is put forward.Sensors are installed at the receiving end of the vehicle and at the transmitting end of each coil on the ground.Through the relative position of the two sensors,the coil in the front path of the car is connected in advance,and the coil of the car passing through is cut off,which reduces the problem of electromagnetic radiation to a certain extent.In the dynamic charging experiment,the input and output current voltage data of different frequency is recorded,the maximum transmission efficiency of this experiment platform is finally found.According to drawing a line chart on the experimental data by the MATLAB software,when the transmitting coil is 7cm from vehicle energy receiving coil in surface energy,on the frequency of 50kHz,power transmission efficiency of the experimental platform can reach up to 28%,increasing 11%compared to the single coil coupling resonance.In the third part,considering the promotion and application of dynamic wireless charging system in real life,we need to invest in the construction and maintenance cost of the facilities.In this paper,by taking the first bus line of Yi Chang city as the object modeling,respectively in three cases of normal operation,road repair and vehicle congestion,we gain the most economical laying scheme of coil array dynamic wireless charging system for electric buses within a certain battery capacity based on genetic algorithm,so as to ensure the economy of the dynamic wireless charging system.Under the premise of realizing the optimal investment cost,real-time monitoring of the electric data of electric buses,adjusting the driving speed of vehicles,and improving the punctuality of buses are also one of the objectives of optimization. |
PDF Full Text Request