Research On Off-grid Photovoltaic Energy Storage Electric Vehicle Charging Pile

Now most of the cars are mainly fuel,the combustion of fuel will emit a large amount of vehicle exhaust,and there will also be pollution problems in the environment,so the development of electric vehicles has attracted the attention of governments.The clean energy used in electric vehicles can reduce the use of fuel,which is of great help to environmental protection,energy conservation and so on.However,the construction and development of electric vehicle charging pile in China is very slow now,which will bring unfavorable conditions for the comprehensive promotion and development of electric vehicle charging pile in the future.Therefore,the off-grid photovoltaic energy storage electric vehicle charging pile studied in this paper is helpful to the development of electric vehicles in China.This paper mainly studies the charging pile of off-grid photovoltaic energy storage electric vehicle,including the theoretical research of off-grid photovoltaic energy storage electric vehicle charging pile,the frame design and control strategy research of electric vehicle charging pile,the hardware and software design of electric vehicle charging pile system,and the function test of electric vehicle charging pile system,the specific research contents are as follows:(1)This paper introduces the working principle of photovoltaic power generation system,and establishes a simulation module to analyze the data in the system.Among them,the maximum power tracking technology method of photovoltaic power generation system is mainly used to improve the control of mountain climbing method in conductance increment method;to analyze the basic structure and performance of AC/DC converter and DC/DC converter;to study the properties of lead-acid battery and supercapacitor;to summarize and compare the three charging methods of electric vehicle charging pile,the system adopts constant current and constant voltage charging method.(2)The overall frame of the charging pile of off-grid photovoltaic energy storage electric vehicle is designed,and the parts of the system are introduced in detail;in the control strategy of mixed energy storage system,the semi-activestructure of supercapacitor and lead-acid battery is combined;in the DC bus voltage control strategy,the power balance of DC bus side output voltage is beneficial to the stable operation of off-grid photovoltaic energy storage electric vehicle charging pile system,so that the energy distribution in the charging pile is reasonable;and the capacity design of off-grid photovoltaic charging pile system.(3)The hardware function design of electric vehicle charging pile system includes PLC controller function selection and resource allocation,man-machine interface module design and selection,IC card reading and writing card module design and selection,electric energy meter module design and selection,printing module design and selection,charging pile system control guidance circuit design,so that the charging pile system has the functions of man-machine interaction,IC card recharge login,printing charging information,power output control and so on.(4)The software design is divided into two parts: the software programming of the PLC controller and the programming of the configuration picture.The STEP7 programming software can make the communication connection between the PLC controller,the IC card reader,the watt-hour meter and the touch screen.(5)The electric vehicle charging pile system designed in this paper can not only charge electric vehicle users,but also have the function of electric vehicle charging pile,which shows that the design of this paper has reached the expected purpose.