不均匀光照下光伏阵列输出特性仿真研究毕业论文
2021-11-08 21:27:37
摘 要
随着社会的发展与科技的进步,人们的物质需求越来越高,全世界范围也出现了日益严重的环境问题,这不得不引起人们的重视。近年来,为了解决能源危机与环境污染问题,世界各国政府都在大力推进诸如太阳能等清洁可再生能源产业的发展。人类利用太阳能的主要方式之一是光伏发电技术,为此,光伏发电在新能源产业中具备极其重要的地位,世界各国也都对光伏发电产业给予了各种支持以促进其发展。由于在实际工作中,光伏发电系统容易遭受各种外界因素的干扰,例如:太阳光照强度、环境温度以及光伏电池本身的遮阴情况等,这些环境因素会导致光伏系统工作电压、电流以及输出功率的波动,极大地影响着光伏系统对太阳能的利用效率,同时也对光伏组件本身的安全性产生不利影响。解决上述问题的方法之一是对光伏阵列进行最大功率点跟踪控制,在保证各光伏组件安全性的同时,使其一直维持当前环境条件下的最大功率进行输出。
本文首先阐述了当前国内外关于光伏发电技术的研究状况,并介绍了本文的主要研究内容和章节安排。其次,对光伏发电系统进行介绍,主要包括光伏发电系统的结构和工作原理,光伏电池等效电路等,并分别对均匀和不均匀光照下光伏电池的输出特性进行总结分析,为后续章节进行光伏阵列的模型建立与仿真实验奠定理论基础。此外,详细分析了光照强度和环境温度等环境因素对光伏电池工作特性的影响。最后,在Matlab/Simulink平台上根据等效电路建立单块光伏板的机理仿真模型,并同时建立了3×3结构光伏阵列的仿真模型。在此基础上,对所建立的光伏组件及光伏阵列模型开展了均匀光照、局部遮阴等环境下的仿真实验研究并得出结论。
由实验结果可知,光伏电池在环境因素变化时,其工作特性确实会受到影响:均匀光照下,光伏阵列P-V特性曲线只有一个峰值,此时对其进行最大功率点的跟踪控制相对容易;在局部遮阴环境下时,光伏阵列P-V特性则呈现出多个峰值,这也增加了其最大功率点跟踪控制的复杂度。
综上所述,本文的研讨工作着眼于分析光伏电池在不同环境下的输出特性,并基于仿真实验重点验证了具有一定规模的光伏阵列在均匀及不均匀光照条件下的输出情况,这对进一步开展光伏系统最大功率点跟踪的研究具有铺垫意义。
关键词:太阳能;光伏发电;光伏电池模型;最大功率点;不均匀光照
Abstract
With the development of society and the advancement of science and technology, people's material needs are getting higher and higher, and there are increasingly serious environmental problems around the world, which have to attract people's attention. In recent years, in order to solve the energy crisis and environmental pollution, governments around the world are vigorously promoting the development of clean and renewable energy industries such as solar energy. One of the main ways for mankind to use solar energy is to rely on photovoltaic power generation technology. For this reason, photovoltaic power generation has an extremely important position in the new energy industry. Various countries around the world have also given various support to the photovoltaic power generation industry to promote its development. Because in actual work, the photovoltaic power generation system is susceptible to interference from various external factors, such as: sun light intensity, ambient temperature, and the shading of the photovoltaic cell itself, these environmental factors will cause the photovoltaic system operating voltage, current, and output power The fluctuation of the solar energy greatly affects the photovoltaic system's utilization efficiency of solar energy, and also adversely affects the safety of the photovoltaic module itself. One of the methods to solve the above problem is to perform tracking control of the maximum power point of the photovoltaic array, while ensuring the safety of each photovoltaic module, so that it always maintains the maximum power under the current environmental conditions for output.
This article first describes the current research status of photovoltaic power generation technology at home and abroad, and introduces the main research content and chapter arrangement of this article. Secondly, it introduces the photovoltaic power generation system, mainly including the structure and working principle of the photovoltaic power generation system. Circuits, etc., and summarize and analyze the output characteristics of photovoltaic cells under uniform and uneven illumination, respectively, and lay the theoretical foundation for the model building and simulation experiments of photovoltaic arrays in the following chapters. In addition, the influence of environmental factors such as light intensity and ambient temperature on the operating characteristics of photovoltaic cells was analyzed in detail. Finally, on the Matlab / Simulink platform, a mechanism simulation model of a single photovoltaic panel is established based on the equivalent circuit, and a simulation model of a 3 × 3 structure photovoltaic array is also established. On this basis, the simulation experiment research under the environment of uniform illumination, partial shading and so on was carried out on the established photovoltaic modules and photovoltaic array models and concluded.
It can be seen from the experimental results that the photovoltaic cell's operating characteristics will indeed be affected when the environmental factors change: under uniform illumination, the photovoltaic array PV characteristic curve has only one peak, and it is relatively easy to track and control the maximum power point at this time; In the shaded environment, the PV characteristics of the photovoltaic array show multiple peaks, which also increases the complexity of its maximum power point tracking control.
In summary, the research work in this paper focuses on the analysis of the output characteristics of photovoltaic cells in different environments, and based on simulation experiments, the output of a certain size photovoltaic array under uniform and uneven illumination conditions is verified, which further It is of great significance to carry out research on the tracking of the maximum power point of photovoltaic systems.
Keywords: solar energy; photovoltaic power generation; Photovoltaic cell model; maximum power point; uneven light
目录
摘要 I
Abstract II
第一章 绪论 1
1.1课题研究背景及意义 1
1.2国内外研究现状 2
1.3本论文主要研究内容 3
1.4论文章节安排 3
第二章 光伏发电系统 5
2.1 光伏电池及光伏发电系统概述 5
2.2 光伏电池的结构及工作原理 5
2.2.1 光伏电池结构 5
2.2.2 光伏电池工作原理 6
2.2.3 光伏电池等效电路 6
2.3光伏电池的输出特性 9
2.3.1 均匀光照下光伏阵列输出特性 9
2.3.2 不均匀光照下光伏阵列输出特性 10
2.4 光伏发电系统的最大点跟踪 11
第三章 外界环境对光伏电池输出特性的影响研究 13
3.1 单块光伏板的工作模型 13
3.1.1 机理模型 13
3.1.2 数值模型 20
3.2影响光伏电池输出特性的因素分析 20
3.2.1温度对光伏电池输出特性的影响 20
3.2.2光照强度对光伏电池输出特性的影响 21