Study On Magnetic Coupling Mechanism Of Wireless Power Transfer For Electric Vehicles

Human beings have been troubled by climate changing, energy and environmentalcrisis for a long time. In this background, the green electric vehicles have arousedpublic attentions. However, problems exist in the conduction charging mode, whichhinders the development and promotion of electric vehicles. In the electromagneticinduction-based wireless dynamic power supply system for electric vehicles, electricalenergy can be transmitted wirelessly from underground track or coil array to thevehicle-mounted battery pack or electric motor, which is a real-time power supply fromroad to electric vehicles. The power track may be needed as long as several kilometerseven dozens of kilometers for the enough power supply to electric vehicles in dynamicwireless power supply system. Research and optimization design of track can make thissystem more stabilized, efficient and economic. And this is an urgent issue to thedevelopment of wireless power supply technology for electric vehicles.This paper studies on the magnetic coupling mechanism of wireless power transferfor electric vehicles. Firstly, this paper expounds the domestic and foreign scholars onthe coupling mechanism of wireless power supply system for electric vehicle, and thenmakes a brief introduction to the basic principle and composition. Subsequently, themutual inductance of the equivalent model of electromagnetic coupling mechanism isanalyzed to discuss the influence factor of the power transmission capacity andefficiency; several common coupling mechanisms are analyzed to study the effects ofthe offset on the stability of the system.The models of centralized and dispersible coils, unicoil and twin coils areestablished base on Ansoft software. Mutual inductance value, the magnetic fielddistribution are analyzed. And several core structures of some typical transmittingterminal are researched by simulating. A more economic and efficient couplingmechanism is put forward to solve the problems such as low efficiency and higheconomic cost.The general design process of coupling mechanism is put forward combined withthe concrete case, and the design of the parameter of coupling mechanism is discussed.Then, the migration simulation experiment was carried out on the new couplingmechanism; the acceptable deviation limits of the system are given.Finally, the experimental platform of the wireless power supply system for electric vehicle is set up; the power test, efficiency tests, migration experiment, stabilityexperiment are carried out. The feasibility of the magnetic coupling mechanismdesigned in this paper is verified by the experimental results verify.