Research On The Maximum Power Point Tracking Algorithm Of Photovoltaic Power Generation System Under Local Shading

The earth’s environment is deteriorating day by day,the resources available for human use are also decreasing.From the perspective of sustainable development,all countries focus on clean and pollution-free solar power generation.As the core part of transforming light energy into electric energy,the output curve of photovoltaic cell is a single peak curve with and only one Maximum value Point.The time-varying nature of photovoltaic cell output affects whether the system can operate efficiently.Consequently.combine the maximum power point tracking(MPPT)technology with the system,provides a better foundation for clean energy power generation to replace traditional power generation.What has mainly investigated in this dissertation are brought forward:Firstly,by learning the physical principles of photovoltaic power generation and engineering models with different parameters,construct mathematical models of photovoltaic cells and photovoltaic arrays,the correlation between its output characteristics and illumination amplitude and temperature was studied.Secondly,the principles of several MPPT methods are analyzed in detail,and their optimal use environment,on this basis.a more complete smart matching algorithm is proposed,feasibility is used as a quantitative indicator,and traditional algorithms arc smartly allocated based on the feasibility,so as to achieve that at any time and in any environment,the system can choose the best MPPT control method for photovoltaic power generation.However,when the photovoltaic cell appears local shading phenomenon,its output curve becomes multi-peak curve,so the traditional MPPT algorithm is easy to fail.This paper proposes to add the amount of current change in the disturbance observation method as the judgment condition to reduce the misjudgment of the disturbance observation method in the case of rapid environmental changes,and use the improved disturbance observation method to determine whether the current environment of the photovoltaic array is partially shaded.If the illumination changes uniformly at this time,continue to use the perturbation observation method to track.If local shading occurs,start the particle swarm algorithm with the voltage limit window to perform a global search.Different tracking algorithms are used for different environmental conditions.According to the mathematical model of the photovoltaic power generation system,the simulation model of PV cell monomer and photovoltaic power generation system is built in MATLAB-Simulink.Simulate the different types of MPPT methods mentioned above and verify their convergence.The comparison shows that the improved algorithm proposed in this paper improves the tracking speed and system stability.