Research On Power Factor Correction Technology In Electric Vehicle Wireless Charging System

Power electronics in wireless charging devices can cause harmonic pollution,so power factor correction devices need to be added to avoid this hazard.On the other hand,the main reason for the lack of large-scale application of electric vehicle wireless charging technology is efficiency.Therefore,the design requirements for the power factor correction part of wireless charging in electric vehicles are relatively high;the efficiency of the power factor correction device is 98%,and the power factor PF of the input network is 0.99.Firstly,the principle of electric vehicle wireless charging technology is introduced.Then,the LCC-S topology is selected as the compensation structure of the resonant converter in the electric vehicle wireless charging device.The LCC-S type circuit simulation model is constructed by MATLAB,and the SS type is adopted.Compared with the compensation structure,it is analyzed that LCC-S has great ad,vantages in reducing current harmonics and improving power factor.Then,the shape of the coil of the resonant converter,the determination of the inductance of the coil,and the sh ape of the core are simulated.Finally,the selected planar coil is selected as the research object.Secondly,according to the research focus of this paper,the power factor correction technology in electric vehicle wireless charging technology,the power loss of the main circuit is analyzed for different types of power factor correction devices,and the interleaved parallel type is finally selected by comparing the loss of different topologies.The power factor correction topology is the subject of research.Then the small-signal modeling of the interleaved parallel topology is carried out,and the voltage-current power-level transfer function of the staggered parallel topology is obtained.It is found through simulation that the system does not meet the stability requirements,and the voltage is designed by the PI controller.The current loop is corrected.The simulation results show that the system meets the stability requirements after adding the PI controller.Then the designed PI controller parameters are brought into the interleaved parallel power factor correction circuit simulation model in the MATLAB/Simulink simulation software.The simulation results show that the input side power factor PF size is 0.995.Finally,the designed voltage-current double-closed-loop power factor correction simulation model is added to the electric vehicle wireless charging system model.The simulation results show that the PF values are above 0.99 under different load effects.The input current THD value and efficiency and other indicators have met the design requirements.Finally,based on the above theoretical analysis and verification in MATLAB/Simulink simulation software,the hardware part and software control part of the interleaved parallel power factor correction device used in the electric vehicle wireless charging system are designed,in which the hardware circuit It is ma:inly composed of main circuit,drive circuit,sampling circuit protection circuit and other modules.The software design is mainly divided into three parts:the main circuit programming flow chart,the voltage and current double closed loop control flow chart and the software protection block diagram.