Research On Dynamic Wireless Power Transmission System For Electric Vehicle

With the development of new energy technologies,traditional fuel vehicles are being replaced by new energy electric vehicles.For solving the shortcomings of traditional electric vehicle wired charging mode,such as low safety,low reliability,low flexibility and poor environmental adaptability,the Dynamic Wireless Power Transmission(DWPT)technology of electric vehicle has emerged as the times require,which can not only greatly improve the endurance of electric vehicle,but also effectively avoid the problem of on-board battery technology limitation,and has a broad market application prospect.Because of the complex dynamic characteristics of the DWPT system and the uncertainty of the driving route,the relative position of the system coupling mechanism is shifted to varying degrees during the driving process,which affects the transmission performance of the system.Aiming at the above problems,this paper studies the DWPT system of electric vehicle.Firstly,the principle and key problems of DWPT technology are analyzed.The influence of resonant compensation network on the transmission performance of the system is analyzed,and the transmission characteristics of wireless power transmission system based on SS and SP resonant compensation networks under different load resistance and coupling coefficient are compared and analyzed,and the mathematical model of TS dynamic wireless power transmission system is established.For further improving the anti-misalignment performance of the system,the resonant compensation network parameters are optimized from the transmission power,efficiency and ZVS soft switch,so that the system can maintain high transmission performance when the coupling coefficient fluctuates.Secondly,the influence of coupling coil structure and other parameters on coupling performance of the system is analyzed,and the coupling mechanism is optimized for improving coupling performance and enhancing the anti-misalignment ability.And a magnetic field simulation model is established by ANSYS software,and the influence of primary coil chain laying spacing,current phase and lateral width of secondary coil on space magnetic field is studied.At the same time,in order to reduce the magnetic leakage degree of the system,the different core structures are analyzed,and a combined core structure is proposed according to the practical application requirements.The simulation results show that the core structure not only effectively realizes the magnetic shielding function,but also improves the coupling ability of the system.Thirdly,based on the above analysis,the low-power DWPT system is designed,and the functions of each module of the system are analyzed in detail.According to the actual operating requirements of the system,the hardware circuit design of each module and the selection of related devices,and the experimental platform of low-power system is built.At the same time,aiming at the fluctuation of output power when the system is offset,an anti-misalignment control strategy based on artificial neural network is proposed.By controlling the duty cycle of DC/DC converter of the secondary side,the output current can be controlled smoothly when the system is offset.Finally,in order to verify the correctness of the parameter optimization of the designed system and the effectiveness of the proposed control strategy,the simulation model is established using Matlab/Simulink.and this paper analyzes the transmission characteristics of the system when misalignment occurs,and verifies the correctness of the theoretical analysis and simulation results analysis and simulation results.