Research On Electric Vehicle Wireless Power Transfer Technology Based On Magnetic Coupling Induction

In order to cope with the crisis of petroleum resources and environmental pollution,new energy vehicles have been vigorously developed around the world.The application of wireless power transfer(WPT)technology to the field of electric vehicle charging can provide more flexible choices for electric vehicle charging methods.Compared with the wired charging method,which would cause wear,tear and potential safety hazards such as sparks due to frequent plugging and unplugging of charging plugs,wireless transfer methods are more convenient,flexible,safe and reliable,which will become one of the development trends of new energy vehicle charging technologies in the future.In this study,double-sided LCC compensation topology and LCC-S compensation topology were analyzed theoretically and studied experimentally based on the WPT technology of magnetically coupled inductive(MCI)electric vehicles.Firstly,with the help of the mutual inductance coupling circuit model and the fundamental wave analysis method,the two compensation topologies were theoretically analyzed,and the relationship between the voltage and current of each component in the two compensation topologies was given.At the same time,the abnormal working conditions were analyzed.Secondly,the main circuit design of the double-sided LCC compensation MCI-WPT system was introduced and an experimental prototype was established for verification.The experimental measurement showed that the output power reached 5kW and the highest efficiency was 91.25% when the vertical distance between coils was 150 mm.Then,the system loss analyze were performed and obtained the maximum efficiency transmission expression,which could provide theoretical guidance for the design of high-efficiency double-sided LCC compensation MCI-WPT.Meanwhile,to suppress the harmonics generated by the loop and reduce the circulating current loss caused by higher harmonic current,the CLCC compensation network was proposed based on the LCC compensation network and verified by experiments.To meet the design requirements of 3KW contactless system,the LCC-S compensation charging system with dual receiving coil structure was studied,aiming at the poor anti-offset ability of single receiving coil and the problem of coupling zero point with transmitting coil.In order to avoid the influence of the magnetic coupling phenomenon between the double receiving coils on the output performance of the system and the damage to the resonance state,a new method of decoupling using a decoupler different from the existing decoupling method was proposed,and based on this method,the experimental prototypes were used to compare the experiments before and after decoupling,and finally the effectiveness of the proposed decoupling method was verified.After decoupling,the maximum efficiency of the system at 3kW output power could reach 93.4%.