Research On Photovoltaic Controller Based On Improved MPPT Technology

Today,when the environment is polluted and energy is scarce,countries all over the world are actively concerned about how to solve the problems of environment and economy,economy and energy how to develop peacefully.As the most promising new energy source,solar energy has undoubtedly become one of the most important research objects in the world.Maximum Power Point Tracking(MPPT)is one of the core technologies to improve the conversion efficiency of photovoltaic cells.It is of vital practical significance to carry out research on the MPPT algorithm for photovoltaics to significantly increase the efficiency of photovoltaic utilization.This design is based on the practical issue of raising the utilization rate of photovoltaic power generation,and studies the problems related to the design and debugging of the MPPT controller based on STM32 in detail,the designed MPPT controller was experimentally validated using the lab’s photovoltaic power generation laboratory equipment.The main work of the thesis is as follows:(1)Construction of Simulation Model of Photovoltaic Power System Based on Boost Circuit.In-depth analysis of the current development and research status of photovoltaic power generation systems at home and abroad,the basic working principle of Buck and Boost circuits is discussed.Using Matlab/Simulink simulation environment,the simulation model of photovoltaic cell and photovoltaic power generation system based on Boost circuit is systematically constructed;(2)Research on MPPT Control Strategy of Photovoltaic Power Generation.Analyzing and comparing the basic characteristics of the commonly used MPPT algorithm,a comparative analysis of the improved observation method of perturbation method — the adaptive variable-step perturbation observation method and the traditional perturbation observation method through simulation.The final simulation results show that the power tracking speed and accuracy of the adaptive variable step perturbation observation method are better than the traditional perturbation observation method,and the superiority of the improved algorithm over the traditional perturbation observation method is proved;(3)Design of MPPT controller based on STM32.The microprocessor adopts STM32.The hardware design part mainly includes Boost circuit,power supply,driving,voltage and current sampling,and temperature and light intensity detection circuit.The software designpart mainly includes the photovoltaic power generation monitoring platform and controller driver program.Through the design and debugging of the controller based on the improved MPPT algorithm,the lab’s photovoltaic power generation experimental equipment was used to verify the power tracking effect of the MPPT controller,and the photovoltaic cell output parameters,light intensity,and temperature data were sent to the photovoltaic power generation monitoring platform for real-time display.Finally,comparing the measured power of the MPPT controller with the ideal power,the average tracking efficiency of the actual power is close to 0.97.