Research On Dynamic Wireless Charging System Of Electric Vehicle Based On Magnetically Coupled Resonance

The problem of traditional fossil energy shortage and environmental pollution is becoming more and more serious.The development of green intelligent transportation has become a hot research topic.Under such circumstances,electric vehicles are also an important means of solving traffic and environmental problems because of their low energy consumption and low pollution.However,the problem of how to charge it quickly and safely and high initial investment costs hinder its marketization.The dynamic wireless charging technology can realize the uninterrupted replenishment of electric energy for electric vehicles and significantly reduce the power battery usage.These advantages make it owing a broad application prospect However,the offset of the receiving end in the dynamic wireless charging system of the electric vehicle may cause the power supply to fluctuate drastically,which affecting the continuity and stability of the power supply.In this dissertation,the dynamic wireless charging system of coil-array electric vehicle based on magnetically coupled resonance is taken as the research object.Aiming to improve the stability of system transmission power and efficiency,Research is carried out from the aspects of the system's power supply structure,compensation network,magnetic coupling mechanism design,and overall system design.The basic characteristics of the LC-S resonant compensation network are mainly studied.The current of primary side coil can be kept constant,independent of mutual inductance and load changes with reasonable parameter configuration.From the perspective of smooth transmission power fluctuation,a dual-emission power supply topology based on LC-S compensation is proposed.It is proved that the output power and efficiency are positively correlated with the sum of the coupling coefficients between the transmitter and pickup when the supply voltage and load are kept constant by theoretical analysis.The output power and efficiency are basically stable when the coupling coefficients are mutually compensated.The magnetic coupling mechanism is studied by Ansys Maxwell simulation software,and the anti-offset characteristics of common coils are analyzed.It is found that the square structure has the advantages of more uniform magnetic induction,higher coupling,and stronger anti-offset capability than circular coil.In addition,the coupling coefficient of dual-emissive structure has complementary characteristics,which can be kept basically stable throughout the power supply cycle.A dual-emission charging topology based on LC-S compensation is proposed in this dissertation.The magnetic coupling mechanism is designed and fabricated,and a 12 W experimental platform is built.The above theoretical analysis and simulation are experimentally verified.During the entire dynamic power cycle,the system's output power fluctuates within 10% and the transmission efficiency reaches 78%.The zero voltage switching of power mosfet is realized,which improves the overall efficiency of the system.The experimental results verify the correctness and effectiveness of theoretical analysis and simulation.