Research And Design Of Electric Vehicle Magnetic Coupling Resonant Wireless Power Transmission System

With the development of science and technology,electric vehicles are favored by people.Compared with traditional wired charging technology,wireless charging has the advantages of safety,beauty,and convenience.Therefore,this thesis aims to improve the transmission efficiency and stability of the system,and study the constant current and constant voltage charging method of electric vehicles.First,the equivalent circuit theory is used to study the magnetic coupling resonance system.By comparing the output characteristics of the series-series and series-parallel compensation topologies,the series-series compensation structure is determined and the frequency splitting phenomenon is introduced.Then compare the phase-shifting and frequency conversion control strategies,determine the frequency conversion control,and realize the electric vehicle charging method of constant current and then constant voltage.At the same time,a MATLAB/Simulink simulation model was built to verify the correctness of the theoretical analysis.Secondly,use Ansys Maxwell software to design and optimize the magnetic coupling mechanism,including coupling coil structure selection,coil wire selection,and adding magnetic cores of different structures to the coil.According to the simulation results,this thesis selects the 8-shaped m-shaped magnetic core structure.Third,carry out the hardware and software design of the system.The hardware part includes the design of inverter circuit,rectifier circuit,sampling circuit and wireless communication circuit.The software part includes the design of primary side and secondary side initialization program,control strategy design,ADC interrupt program design and serial port programming.Finally,a wireless charging experiment platform with a power of 500 W was built,and wireless power transmission experiments under different distances were performed to verify the frequency splitting phenomenon,transmission efficiency and stability of the system.Both experimental results and simulation results show that this design scheme has strong practicability.