Research And Design Of Photovoltaic Charging Pile System For Electric Vehicles

With the continuous development of new energy electric vehicle industry,photovoltaic power generation technology and modern power electronics technology have attracted more and more attention from researchers.As a typical representative of new energy sources,solar energy is favored by people for its clean,resource-rich and energy-rich advantages.Electric vehicle photovoltaic charging pile system is an important application of solar energy resources.Solar cells are the main equipment for the energy source of photovoltaic charging pile systems.Its performance determines whether the charging pile system can provide high quality and stable output power.This article focuses on the in-depth study of the control strategy and charge management of the electric vehicle photovoltaic charging pile system.Three novel DC-DC converter circuits and charging management systems are designed.The main research contents are as follows:Aiming at the shortcomings of the traditional DC-DC converter circuit for electric vehicle photovoltaic charging piles,an improved Buck converter circuit is designed to effectively realize ZCS turn-on,ZVS turn-off,and improves switching tube loss problem.A new type of high boost ratio Boost converter circuit uses switching inductance technology to improve the circuit's boost capability and working efficiency.A new wide-gain Buck-Boost converter circuit with embedded LC.The resonant circuit realizes the circuit wide gain and loads dynamic characteristics.MATLAB/Simulink simulation tools are employed to complete the modeling of the three new circuit structures.Analyzing the working principle of the new circuit structure and the theoretical calculation with various components and parameters,and completing the circuit simulation experiment in the open-loop mode.To verify the correctness and feasibility of the theoretical analysis of the new circuit structure,the simulation results are compared with the traditional DC-DC converter circuit and related literatures.At the same time,the research was conducted on the electric vehicle charging management system.This article uses the Android-based embedded operating system,Cortex-A9 series industrial ARM processor,Exynos4412 development board which supports capacitive touch screen operation function,and designs a new type of electric vehicle charging management system.The thesis introduces the design method and specific functions of the charging management system in detail.Including that the design of window functions,the transmission and analysis of real-time charging data,cross-compilation and kernel transplantation.JNI is invoked through the local method to complete the development of the RS485 serial port communication driver.And a corresponding serial port communication transmission protocol was formulated,which can effectively transfer the charging data and charging instructions.Thereby,effectively manage the entire charging process.Finally,a low-power electric vehicle photovoltaic charging pile experimental system platform was set up,and experimental tests were conducted on the platform.The output waveform,charging efficiency and system stability of the photovoltaic vehicle charging pile system for electric vehicles were tested and analyzed.The experimental test results show that the prototype of using the low-power electric vehicle photovoltaic charging pile system with photovoltaic power generation technology,DC converter technology and Android embedded development technology have the characteristics of simple circuit control,wide gain,and high efficiency.The interface of the charging pile complies with the latest requirements for charging indicators of electric vehicles promulgated by the country.This system design has a certain enlightening significance for the construction and promotion of the photovoltaic charging infrastructure for electric vehicles and has a high practical value.