Study On Improving The Output Efficiency Of Photovoltaic Array Under Local Shadow

Photovoltaic power generation is a clean energy source,which is used more and more widely.However,buildings,clouds,trees and dust on the surface of photovoltaic cells make the illumination value of photovoltaic cells unsteady,which makes the output of photovoltaic cells diversified,and there are many peaks in the output characteristic curve,which makes the traditional maximum power point tracking(MPPT)algorithm easy to be misjudged.It is difficult to track the maximum power point effectively,which leads to the decrease of output power and work efficiency of photovoltaic power generation system.Therefore,it is necessary to explore ways to improve the output power of photovoltaic power generation system under local shadow conditions.Based on the analysis of research work at home and abroad,the physical interface model of photovoltaic module is designed to realize series and parallel connection of photovoltaic module,and the output characteristics of photovoltaic array are simulated under uniform illumination and local shadow respectively.Then,the photovoltaic arrays with different structures composed of several photovoltaic modules are compared and analyzed,and the output efficiency of different series-parallel connection modes of photovoltaic modules under local shadow state is studied,among which TC T structure is better.Then,based on the structure of TCT,an optimization method of photovoltaic array structure with shadow separation is proposed,and the effectiveness and theoretical feasibility of this method are verified by modeling and simulation analysis.Finally,a MPPT control method based on double-enhanced PSO algorithm is proposed.The basic particle swarm optimization algorithm is optimized by fixed restart judgment and power change trend.This method can effectively avoid mutation.It is easy to fall into the problem of local maximum power point under the condition of misjudgement of maximum power point and local shadow.It can track the maximum power point quickly and accurately,and the system oscillation is small.In this paper,from the two perspectives of hardware structure adjustment and software algorithm optimization of photovoltaic power generation system,we can achieve the purpose of improving the output efficiency of photovoltaic power generation under local shadows.