Research On Fast Charging System Of Electric Vehicle Based On DSP

With the continuous increase of car ownership in China,the problems of energy shortage,traffic congestion and environmental pollution are becoming more and more serious.Electric cars are favored by the world countries because of their high efficiency,energy saving and environmental protection,and become the main direction of automobile industry development.The rapid charging system of electric vehicle is the premise and fundamental of the development of electric vehicle,which is one of the necessary conditions for promoting the commercialization and industrialization of electric vehicles.This paper studies the related technology of ev charging system,and it is of great significance to the development of electric vehicle in order to realize the charging process of ev more quickly and safely.The research of electric vehicle rapid charging system mainly includes three aspects:charging method research,hardware circuit design and software design.The fast charging method is one of the key contents in this paper.The quality of charging method directly affects the speed,safety and life of battery.This paper presents a piecewise pressure limiting fixed cycle,positive and negative pulse constant current charging method and the charging system main circuit small signal model is established,under the environment of Matlab simulation,fuzzy PID control algorithm for circuit simulation,verify the feasibility and effectiveness of the system control strategy.The hardware circuit design mainly includes the design of charging main circuit and control circuit.On charging main circuit design,this paper adopts full bridge phase shifting control ZVZCS PWM DC/DC converter as the charging system main circuit topology structure,work mode and implementation are analyzed in detail according to the conditions,and the main circuit of each device selection and parameter calculation,implement circuit soft switch technology,improve the system of charging speed and efficiency.Late in the battery charging,there are serious polarization phenomenon,this article also innovative design the discharge circuit of depolarization,realize the energy recovery circuit and battery discharge condition,and provides a theoretical basis for subsequent research time support.The design of charging system control loop is based on DSP TSM320F2812,which mainly includes driving circuit,sampling circuit,auxiliary circuit and so on.Sampling circuit through the real-time information such as voltage,current and temperature,the control system of A/D conversion module analyzes data processing,in order to control the switch tube conduction and shut off,and adjust the voltage,current size of the system output.The software design mainly includes main program design,A/D conversion program design,PWM program design,fuzzy PID program design,etc.In the process of charging,first enter the main program loop,and call each corresponding subroutine to realize relevant functions according to the charging needs.Under the interaction of these programs,the goal of charging system efficiently,fast charging and extending battery life is realized.Finally in the previous chapters on the basis of the analysis and design,through the Matlab/Simulink simulation platform of phase-shift full bridge ZVZCS charging system design and simulation,the simulation results verify the feasibility of this design,satisfy the charging system performance index,realizes the electric vehicle charging system of rapid,efficient and safety charging.