| Compared to the traditional vehicle charging way, wireless charging electric vehicles to achieve a safe, convenient, flexible, reliable, no direct electrical connection has. The magnetic resonance wireless charging technology and on the basis of existing research, relationship for the coupling coefficient and former vice line ring position changes, launched a further theoretical study and simulation. And the charging of the whole system is analyzed and simulated, soft switching technology and the frequency conversion control reference, to improve the transmission efficiency of the system.Firstly, this paper introduces the traditional electric vehicle charging shortcomings and inadequacies of the way, put forward the research of wireless charging system for electric automobile. An overview of the wireless charging technology for electric automobile in the domestic and foreign research status, the main research results and development trend.Then, analyze the comparison of the three kinds of radio transmission mode in the application of electric vehicles and the advantages and disadvantages, this paper applies electric vehicle wireless charging technology method was selected. Derive the equivalent circuit model of magnetic resonance and in consideration of the original, secondary winding resistance of 4 kinds of compensation circuit resonant coupling capacitance were design parameters, analysis system in each part of the impact on the output power and transmission efficiency factors. Rectifying and inverting circuit respectively from the choice of power electronic devices, the switch tube control mode and the power to transform circuit topology structure three aspects carries on the analysis.Secondly, comparative analysis of the selection and design of two kinds of coil structure, choose two coil structure and cylindrical helical coil. This paper applies the coupling coefficient for former coil wireless charging system for electric vehicles in different space position were studied. Through theoretical derivation, the coupling coefficient formula of former coil in different spatial positions by using the MATLAB simulation, and the relationship between the coupling coefficient for the two coil position change. And the further use of Ansoft HFSS electromagnetic simulation software to verify the power core in the process of transmission and the space around the magnetic field distribution is studied, the relationship between the coupling coefficient and the position offset of the two resonant coil. In order to verify the correct the derivation of the formula.Finally, introduces the electric vehicle wireless charging principle, and introduces the soft switching of the working principle and the realization of the condition, through MATLAB simulation software to realize the soft switching control switches, to verify the correctness of the design parameters. In the foundation to realize the soft switching, detailing the work principle of the variable frequency control method, through the simulation of MATLAB software, the radio reference to transmission system topology characteristic and the circuit parameter design. In Simulink to build the simulation model of the system. |
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