Research On Tracking Method Of Maximum Power Point Of Photovoltaic Cells In Partial Shadows

Nowadays the resource crisis is getting worse,and the problem of environmental pollution is still serious.The development and application of clean energy is an effective means to optimize the energy structure,as well as an effective means to solve the current global resource crisis and environmental pollution problems.Therefore,as a renewable energy source that is easily available and utilized,solar energy has developed rapidly in recent years.In the research of photovoltaic power generation,the modeling of photovoltaic cells is the basis of the research.The five-parameter model is mainly used in the current research.The parameter extraction has always used a more cumbersome numerical calculation method.This paper improves the photovoltaic cell model,proposes a parameter extraction method based on the iterative method of the cell model,and analyzes the errors of the five parameters in the model.It provides a simulation unit model and a theoretical research basis for the subsequent research on the characteristics of photovoltaic modules.The environment of the photovoltaic power generation system is complex,and it is difficult to avoid the problem of some components being shaded.The photovoltaic array exhibits diverse output characteristics under different partial shadow conditions.Therefore,the article analyzes the influence of different photovoltaic array layouts and connection methods on the output characteristics of photovoltaic arrays under the influence of different forms of partial shadows through simulation experiments.Subsequently,the article built a variety of photovoltaic array models,and performed simulation experiments by setting a variety of different forms of partial shadows,and finally got the characteristics of the influence of partial shadows on the photovoltaic array.It provides an optimization basis for the following tracking algorithm.Partial shading will cause the efficiency of photovoltaic power generation to decrease.The maximum power point tracking(MPPT)of photovoltaic power generation is one of the effective ways to improve the efficiency of photovoltaic power generation.Traditional tracking algorithms may have misjudgments.However,modern control theory algorithms have more iterations and require higher computing capabilities for computers,so engineering applications are more difficult.In response to this problem,the article built a simulation model of the photovoltaic power generation system that can be applied to the simulation experiment in Matlab.Based on this,the MPPT control method of photovoltaic cells under partial shadow based on the steepest descent method is proposed.The theoretical derivation of the steepest descent method and the feasibility verification of its application in the MPPT process of photovoltaic cells have been completed.The algorithm flow is improved,and the iterative formula of the algorithm is improved.Finally,a solution to the local extremum that the traditional method is easy to fall into is proposed.Finally,the article designs an 8×2 photovoltaic array simulation model for simulation analysis.Simulation tests were performed on the photovoltaic cell model and the 8×2 photovoltaic array model under uniform lighting conditions and partial shadows.Subsequently,the particle swarm algorithm and the algorithm based on the steepest descent method were used to carry out the simulation experiment of MPPT,and the parameter values of the two algorithms were analyzed and discussed respectively,and the comparison and analysis were carried out according to the simulation results.