Research And Design Of Solar Cell Simulator Based On STM32

On the background of increasing energy consumption and environmental problems at home and in the world,the party and government put forward the slogan "green water and green mountains are mountains of gold and silver".New energy development led by solar energy has become the focus of people's attention.In the process of solar energy development and utilization,real solar photovoltaic cells are vulnerable to environmental factors,which makes the experimental data inaccurate,leading to the reduction of solar energy development efficiency and the slowdown of the development process.Using solar cell simulator to replace real solar cell array for the development and research of solar cell not only improves the development efficiency,but also greatly reduces the development cost.Therefore,the research on solar cell simulator is as follows:(1)The working principle of solar cells and the general solar cell system are analyzed,and the output characteristics of solar cells are analyzed.On this basis,the working principle of the solar cell simulator,the structure of the solar cell simulator designed in this paper and the working point determination principle are introduced.Moreover,the physical and mathematical model of the solar cell is used to carry out Matlab simulation on the output characteristics of the solar cell under different environmental conditions,which verifies the correctness of the model and lays a foundation for the development of the simulator.(2)The hardware circuit of the solar cell simulator is designed.After comparing five kinds of main circuit topology including buck,flyback,normal shock,half bridge,whole bridge,according to the requirements of this topic and the advantages and disadvantages of practical circuit application,the normal shock topology is choosing as this topic main circuit topology structure.And on this basis,according to the topic request to other circuit design,including designs of the auxiliary circuit,and design of the voltage and current sampling circuit,isolation drive circuit etc.At the same time,the hardware circuit components are selected.(3)The software control part of the solar cell simulator is designed,including theintroduction of the microcontroller stm32f103rct6 and the intrmodel required in the program.In terms of control algorithm,this paper analyzes the advantages and disadvantages of table lookup method,slope-intercept method and point-by-point approximation method.On this basis,a new algorithm,variable-step binary approximation method,is proposed to improve the operation efficiency and accuracy of the simulator.(4)After the hardware and software parts of the simulator are designed,matlab simulation and corresponding experiments are carried out on the simulator to verify the rationality and practicability of the designed simulator.During the experiment,different algorithms were compared on the stability of the simulator output and the output adaptation to the sudden change of load and environment.It was verified that the variable step size binary approximation method had the advantages of tracking speed and good stability,which laid a good foundation for the application of the simulator.