Research On Maximum Power Point Tracking Method Of Photovoltaic Power Generation System

Solar energy can effectively alleviate the world energy and environmental crises as a new energy.But at present,the utilization efficiency of solar power is relatively low,and the stability of power supply is not high,the original control algorithm can not solve these problems well.While the tracking speed of perturbation and observation method with large step is very fast,and the tracking accuracy of Newton method is very high,taking the maximum power point tracking algorithm as the research object,it proposes an improved optimization algorithm based on the perturbation observation method and the Newton method which combines the advantages of the two control algorithms,it has a certain improvement in tracking speed,tracking accuracy and stability.Firstly,the working principle of photovoltaic cells is introduced and the equivalent mathematical model of photovoltaic cells is analyzed,the mathematical model is used to reflect the change rule of the output characteristics of photovoltaic array under external conditions.Finally,the model of photovoltaic cells is established based on the equivalent mathematical model,and the influence of external conditions on the output characteristics of photovoltaic array is analyzed,and the conclusion is that the stronger the light intensity and the lower the ambient temperature are,the higher the output power is,which verifies the importance of MPPT research.Then the basic principle of MPPT and the classical MPPT algorithm and several improved algorithms are analyzed,mainly by constant voltage method,incremental conductance method,perturbation and observation method,the improved incremental conductance method and the improved perturbation and observation method,and analyzes the working principle,working process,advantages and disadvantages of each algorithm in detail.Then the modeling and Simulation of perturbation observation method and incremental conductance method are carried out to analyze the effect of tracking step size on maximum power point tracking,finally it gets the conclusion that the smaller the step size is,the slower the tracking speed is,but the better the tracking accuracy and stability are,so as to determine the relative compromise step 0.005.Finally,a perturbation observation method and Newton method based on the combination of algorithms is proposed aiming at the shortage of the original algorithm.In the early stage of the algorithm,a large step perturbation observation method is used to quickly reach the maximum power point.When the disturbance direction is changed for the first time,the Newton method is used to determine the final maximum power point.A simulation model based on Boost circuit is established,to compare with the perturbation and observation method and the improved perturbation and observation method to prove the superiority of the improved algorithm;finally it designs a photovoltaic power generation device by the angle of the light automatic adjustment based on the improved algorithm.