Research On Maximum Power Point Tracking Of Photovoltaic Power Generation System Based On Linear Active Disturbance Rejection Under Complex Lighting

Since the 21 st century,energy has become an indispensable part of modern life and work.In the process of people's transformation and utilization of natural resources,fossil energy reserves are in crisis,and solar energy,which is a renewable energy source,is receiving more and more attention.In photovoltaic power generation systems,the output power of photovoltaic cells is easily affected by temperature and light intensity,which causes large fluctuations.Therefore,one of the research hotspots of photovoltaic cells is the research on the maximum power point tracking(MPPT)technology.Based on the complex nonlinear problems and unknown disturbances of the output characteristics of photovoltaic power generation systems,the thesis analyzes the advantages and disadvantages of MPPT algorithms for photovoltaic power generation systems under uniform illumination,and studies the MPPT method of photovoltaic power generation systems based on linear auto-disturbance disturbance controller.The outer loop adopts improved variable step size disturbance observation method,and the inner loop adopts linear auto-disturbance to achieve voltage closed-loop control,thereby achieving the purpose of fast and accurate tracking.The paper simulates and compares the disturbance observation method before improvement and the improved algorithm respectively;and by simulating the measured temperature and light intensity in a photovoltaic power station for one day,and comparing with the measured power curve,it shows that the algorithm has good applicability and anti-interference.At the same time,considering the fact that the photovoltaic power generation system will have partial shading in practical applications,the traditional algorithm for multi-peak problems generated by the photovoltaic power generation system under the shade can easily fall into local extremes,and it is difficult to track or even lose the maximum power point.This paper uses particle swarm algorithm to realize global MPPT under shading conditions,while still using linear auto-disturbance controller to achieve voltage closed-loop control,which improves the working efficiency of photovoltaic power generation systems.The basic particle swarm optimization algorithm is optimized and improved,so that its application in the photovoltaic power generation system can update the speed and position of particles stably and globally after a certain number of iterations.The outer loop uses an improved particle swarm algorithm to obtain the global maximum power point while the inner loop uses a linear auto-disturbance controller to perform voltage closed-loop control,enabling the photovoltaic array to work quickly and stably at the maximum power point.The static and dynamic shading of 6*1 photovoltaic arrays are simulated and compared with the traditional particle swarm algorithm.The results show that the algorithm in this paper has improved tracking speed and tracking accuracy.In short,through Matlab / Simulink experimental simulation,it is verified that the optimization algorithm in this paper can effectively improve the tracking time and tracking accuracy of photovoltaic power generation systems under uniform lighting or partial shading conditions.