Research On Wireless Power Supply Technology Of Electric Vehicle

With the rapid development of the world economy,the global crisis of fossil energy is becoming more and more serious.The lack of fossil energy and the environmental pollution caused by its use are the main problems facing all countries.Electric vehicle has the advantages of low price,low pollution and low noise,and it is an effective way to solve the shortage of fossil energy and environmental pollution.At present,the promotion of electric vehicles is still in a dilemma.The charging problem of electric vehicles restricts the development of electric vehicles.This paper studies the key technology of radio power transmission based on magnetically coupled resonance electric vehicles.Firstly,the wireless power supply system of magnetically coupled resonant electric vehicle is summarized,and the wireless transmission process of electric energy from ground transmitter to vehicle receiver is briefly described.In order to improve the transmission performance of the system and effectively protect the primary and secondary side circuits,the high frequency inverters and the primary and secondary side compensation topologies of the system are analyzed,and then the appropriate full bridge inverters and series-series compensation modes are selected.Secondly,the magnetic coupling mechanism is optimized and simulated,and the advantages of square coil are determined through the simulation and comparison of circular coil and square coil by Ansoft Maxwell.Based on the commonly used core structure,the improved Type I and Type II core structures are proposed.The superiority of the Type II core structure is determined by simulation calculation.In order to reduce the radiation effect of electromagnetic field on human body and the leakage of the original secondary coil,an optimization scheme of magnetic shielding for magnetic coupling mechanism is proposed.Through the research and analysis,the offset tolerance of the magnetic coupling mechanism is defined.The relationship between system efficiency,transmission power and side output voltage with mutual inductance,system frequency and load resistance under constant voltage and constant current input conditions is studied in depth.The optimal efficiency of load subsection interval system is studied,and DC-DC converters with various working modes are proposed to ensure that the system efficiency optimization tracking is still achieved when the equivalent load resistance changes in a wide range.The experimental platform of the system is built to verify the correctness of the theoretical analysis and the practicability of the device.