Circcuit Design Of DC Charging Pile

In this paper,a circuit of DC charging pile is designed with the increasing popularity of electric vehicles and the increasing attention paid to charging technology.The suitable topology and control strategy are designed according to the analysis and research,which meet the specific requirements.In this paper,the topology of the traditional PFC circuit and the bridgeless PFC circuit are analyzed and the advantages and disadvantages of each topology are discussed.The improved bridgeless Boost PFC circuit is chosen as the front structure of the DC charging pile.The working process of the improved bridgeless Boost PFC circuit is analyzed in detail,and its mathematical model is established.In addition,several common bridgeless PFC control strategies are briefly introduced.On the basis of analyzing the common topology of DC/DC circuit,the phase-shifted full-bridge DC/DC transform circuit is chosen as the back stage structure of the DC charging pile in this paper.The working principle of the phase-shifted full-bridge DC/DC transform circuit is analyzed in detail.The ZVS switching condition and the loss of the secondary duty cycle of the circuit are studied,and its small signal model is established.In addition,the single closed loop control and the double closed loop control strategies are briefly introduced.On the basis of analyzing the basic principle of one cycle control strategy,this paper analyzes the working principle of one cycle control strategy in bridgeless Boost PFC circuit in detail,and analyzes its stability condition.Then,the concept of current control mode is introduced.The peak current control mode and the average current control mode are analyzed,and the working principle of the average current control mode in the phase-shifted full-bridge DC/DC transform circuit is analyzed in detail.Based on the above theoretical research,according to the specific index,the specific parameters of the bridgeless Boost PFC circuit and the specific parameters of the phase-shifted full-bridge DC/DC converter are designed.According to the control requirements,the corresponding control circuit is designed.Finally,the simulation model is built in Matlab/Simulink software.The simulation results show that the output voltage is stable,having a smaller ripple value and meeting the expected requirements.The feasibility and effectiveness of the designed circuit and control strategy are verified.