Modeling And Experimental Study Of Energy Distribution Of Solar Photovoltaic Devices

Solar energy is recognized as one of the clean energy in the world,and the photovoltaic(PV)device that converts solar energy into electrical energy is one of the typical forms of the conversion and utilization of solar energy.At present,the research of PV device mainly focuses on two points:how to accurately simulate its electrical-thermal performance,and how to improve their electrical efficiency in the future.However,on one hand,the PV conversion mechanism is complex and profound.It is the product of the interaction of thermodynamics,quantum physics and wave optics,and is also the subject of interdisciplinary integration.On the other hand,their actual operating environment is uncertain.On different days,the actual performance of the same PV device will be quite different.Therefore,the complex photoelectric conversion mechanism and the changeable operating environment bring great challenges in the research of the performance evaluation and efficiency promotion of PV devices.This paper aims to explore the comprehensive energy distribution of solar cells and PV modules under different conditions.The research is divided into four parts.Firstly,this paper analyzes the working principle of the PV cell,and makes a scientific definition and division of the cause of its energy losses.Specifically,the losses are divided into the loss happened in the carriers’ generation,transportation and recombination process in the cell.Also,the connection losses from cell to module are concerned.Then,after the establishment and verification of the loss model under the standard test condition,this paper proposes a comprehensive performance simulation model by introducing five-parameter electrical model and thermal resistance model.By coupling these three models,this paper unifies the macro performance characterization and micro working mechanism of the PV module,and simulates its electrical-thermal performance and energy distribution under the actual conditions.The third stage is to verify the coupled model through experiments.After comparing the simulation data and experimental data in summer and winter,sunny and cloudy days,the accuracy of the model is verified.The results show that the actual power generation efficiency of this PV module is 14.39% on the sunny day in summer.When the solar radiation enters the module,21.85% of the total energy will be dissipated in the environment due to the optical reflection of the cell itself or the inactive areas in the module.Among all the losses,spectrum mismatch loss accounts for the largest proportion,which is 37.33% of the total incident energy.As a result,63.76% of the incident energy will eventually be converted into the heat source,rising the working temperature of the module.Finally,based on the combination of experimental results and theoretical analysis,this paper systematically presents some specific measures of thermal management and efficiency improvement according to different loss mechanisms.Some of measures aim to reduce losses to maximizing the device efficiency within the limit efficiency.Others introduce new technologies to increase the generation of carries in PV cells,so as to break through the existing efficiency limitation.At the same time,according to the existing research results,this paper also puts forward the work plan and future outlook,showing the sustainability and coherence of this research.