Research On PWM Rectifier Of Preceding Stage For Electric Vehicle Charging Pile

The rapid development of electric vehicles in the world has led to the construction of charging pile infrastructure and accelerated the research and application of PWM rectifier technology for preceding stage of charging piles.The PWM rectifier for preceding stage of charging pile has the following advantages:unity power factor,stable DC voltage output,good dynamic performance,and energy bidirectional flow.In this thesis,the working principle of PWM rectifier is analyzed,and experimental platform is built to verify software algorithm and hardware design.This thesis mainly completed the following work:(1)Analysis and comparison of the advantages and disadvantages of the common voltage type PWM rectifier and the application situation,the three-phase voltage type PWM rectifier topology is adopted in the AC/DC transformation for preceding stage of charging piles.In the condition of grid voltage balance,the mathematical model of PWM rectifier is analyzed,and its basic working principle is expounded.(2)The control method of three-phase voltage type PWM rectifier for charging pile is expounded.According to the mathematical model in the synchronous rotating coordinate system,direct current control is adopted,the double closed-loop control of the voltage outer loop and the current inner loop.(3)In order to improve the utilization of DC voltage,SVPWM modulation method was adopted to establish SVPWM algorithm simulation model in MATLAB to verify the correctness of algorithm design.At the same time,a three-phase voltage type PWM rectifier system simulation model for charging piles was established to verify the operating characteristics of the system under different conditions such as rectifier,inverter,load disturbance,and grid disturbance.(4)On the basis of simulation,the hardware design of the entire system is completed,including main circuit parameters design,signal conditioning circuit design,drive circuit design,and control circuit design based on TMS320F28335.(5)Based on TMS320F28335 for system software is designed,mainly including:three-phase software phase-locked loop to capture the grid voltage phase,incremental PI control algorithm,SVPWM modulation algorithm,AD sampling design.Finally,the experimental platform of the system is built,and the experimental verification of the algorithm is carried out on the experimental platform.The experimental results and simulation results are basically the same,and the correctness and feasibility of the software algorithm and hardware design are verified.