新型光伏阵列等效串联电阻的计算模型

该文提出一种新型光伏阵列等效串联电阻的简化计算模型,同时在该模型的基础上,提出一种等效串联电阻的工程应用模型。该模型基于光伏电池的工程电路模型,通过推导光伏阵列最大功率点时的输出电压和电流关系以求得光伏阵列运行在最大功率点时的等效串联电阻;基于光伏阵列实时运行参数与环境参数、标准情况下运行参数的关系,通过简化计算模型计算获取实时的光伏阵列等效串联电阻。现场实验结果表明:以上两种模型的计算值误差均在8%以下,满足工程精度要求,具有较高的实际工程应用价值。     

基于光伏阵列数学模型的Matlab仿真

以光伏阵列的数学模型为基础,应用Matlab/Simulink仿真工具建立一种光伏阵列的仿真模型。详细介绍光伏阵列仿真建模过程,应用牛顿迭代法对数学模型进行解析。该模型能分析太阳能光伏电池阵列所具有的随着光照强度和温度不同而变化的P-V和I-V非线性特性。仿真结果表明:该模型输出的光伏阵列特性曲线与实验测试结果基本相符。     

基于Simulink和PSIM的光伏阵列的联合仿真

基于光伏阵列的工程数学模型,在matlab环境下,采用S函数,开发出了一种光伏阵列的仿真模型。该模型可以模拟任意环境温度和光照强度下的光伏阵列特性。考虑到PSIM对于功率级电路仿真的优越性,在PSIM中建立光伏阵列应用的变换器,在matlab中采用S函数建立其控制模块,将两者协调起来,达到较好的仿真效果,具有精确性和通用性,为其它电路的协调仿真提供了参考。     

光伏产业的阳光企划

美国近期公布的光伏产业路线图预测到2030年,光伏发电将占到美国峰值发电容量的10%,并且能够同时占据相当可观的国际市场。目前光伏供电主要应用在太空领域及发展中国家相对隔绝的偏远地区,西方发达国家已经在家居与办公建筑中局部应用了太阳能系统。尤其在没有并网的地区或应用环境中,光伏电池的优势地位不言而喻……本文讲述了光伏产业的世界格局、薄膜光伏电池产业的发展及当今产业巨头的战略布局     

并网光伏电站光伏组件支架最佳倾角设计研究

大型并网光伏项目组件的倾角直接影响光伏电站的发电量,因此如何选择最佳倾角具有重要意义。本文从不同倾角的光伏电站收入和成本变化进行分析,建立了费用效益模型,从全寿命周期效益最大化角度出发,有效地解决了大型并网光伏项目最佳倾角的选择问题。最后以实际工程验证了模型的有效性,同时通过土地价格变化,对倾角影响进行了敏感性分析,结果表明随着土地单价的提高,倾角越小,整个项目经济性越好。     

中国光伏产业发展现状与挑战

一、世界光伏产业发展现状与展望 1．世界光伏电池产量及安装容量快速增长 光伏产业是世界发展速度最快的行业之一。为了实现能源和环境的可持续发展,世界各国将太阳能光伏发电作为新能源发展的重点,在各国政府、特别是各发达国家政府的大力扶持下,世界光伏产业发展迅猛。     

西门子S7-300PLC在光伏发电数据传输中的应用

一、系统概述太阳能光伏发电系统一般分为若干个区域安装光伏组件分别建在房屋顶上,在建筑顶层平面将设置若干控制室与光伏阵列相对应,产生的电能就近并网,系统主要由光伏组件、直流汇流箱、集中型逆变器、交直流控制设备、数据采集和通讯系统等几部分组成。（见图1监控系统拓扑图）本文主要介绍数据通讯系统功能。     

关于最大功率点追踪的一些讨论

随着化石能源的日益枯竭,人们对环境保护问题的重视程度也在不断提高,寻找洁净的替代能源问题变得越来越迫切。太阳能作为一种可再生能源,不仅洁净无污染,而且可持续利用,因此有着广阔的应用前景,光伏发电技术越来越受到人们的关注。但在光伏并网发电系统中光伏阵列的最大功率点跟踪作为关键问题,一直影响着光伏发电系统的效率。本文针对光伏阵列的最大功率点跟踪讨论了几种传统的追踪方法,并对滑模面零均值动态的准滑模控制方法进行分析。最后得出滑模面零均值动态的准滑模控制方法相对于传统的追踪方法具有实现简便,而且有很好的跟踪效率和性价比,适用于温差大、光照变化剧烈和不能充分照射的场台。滑模面零均值动态的准滑模控制方法具有很强的鲁棒性、高精度和高效性,具有广泛的应用价值。     

极区集成式光伏供电装置结构设计与分析

太阳能独立供电是解决南极野外长周期观测活动供电问题的重要途径之一。针对极区特定环境,设计了一种基于集装箱的可移动光伏供电装置。首先,构建了在结构集成化约束条件下光伏组件斜面上太阳辐射量计算模型,确定了光伏组件最优安装倾角;其次,利用CFD （computational fluid dynamics,流体动力学）方法分析了在最优安装倾角、不同风向角时光伏组件的风载荷,并确定了光伏组件的典型风载荷工况;最后,通过有限元方法分析了在典型工况下光伏支架的力学性能。结果表明,对于集成式双排光伏组件,上、下排光伏组件的最优安装倾角分别为29°、39°。光伏组件存在3种典型工况：当风向角为20°时,2排光伏组件均受到下压作用;当风向角为120°时,一排光伏组件受下压作用,另一排受上抬作用;当风向角为140°时,2排光伏组件均受到上抬作用。在3种典型工况下,光伏支架的最大应力为103.93 MPa,安全系数达2.98,满足强度要求;2排光伏支架铰接处的变形较大,最大值为4.33 mm;支架变形分布受风向影响较大,其中来风侧变形量达3.7 mm,另一侧变形量小于1 mm。研究结果可以为解决极区野外长周期独立观测活动的电能供给问题提供一定的参考。     

太阳能光伏空调研究及进展

本文从目前传统空调技术的能量利用效率和光伏发电的光电转换效率的提升说明了太阳能光伏空调广泛应用的主要技术条件已经成熟;从光伏组件价格下降、光伏系统投资回收期缩短和光伏安装占地面积减小说明光伏空调的经济成本已经下降到可与传统空调竞争的范围。文中介绍了四种光伏空调的结构,描述了其实际运行测试的实验过程、各评价指标及运行效果,提出太阳能光伏空调需要深入研究的方向,即高效率的光伏直驱空调、光伏空调与补贴政策、控制策略、行为与节能的关系,以及光伏空调设计软件。     

我国太阳能光伏产业现状及未来展望

太阳能光伏发电是可再生能源利用的重要形式,也是我国目前重点发展的、为数不多的具有全球竞争力的战略性新兴产业之一。本文详细分析了太阳能光伏产业国内外发展现状及未来趋势,分析了我国太阳能光伏产业现状和存在的问题,对光伏产业的健康发展提出了若干建议并对光伏产业的未来发展进行了展望。     

国内外用户侧光储系统发展应用研究

随着分布式光伏越来越多地接入电网,光储系统作为提高系统稳定性、减少用户用电成本的有效手段,已成为新能源应用的重要发展方向。首先研究了欧美、日本等发达国家用户侧光储系统应用现状,并在此基础上总结了国外用户侧光储系统发展的重要条件和技术路线。然后,介绍了国内商业用户、工业用户和居民用户光储项目,分析了国内用户侧光储系统发展所面临的难题和困境。最后,根据国外应用经验,结合国内电动汽车充电桩迅速发展的现状,提出了发展建议,对国内用户侧光储项目的健康发展具有一定的借鉴意义。     

分布式光伏储能系统综合效益评估与激励机制

配电网中分布式能源渗透率不断增加,其有效消纳与控制成为新的热点课题。储能和分布式发电系统的结合可以平滑这些间歇电能并网,降低光伏发电对电网的冲击,并提高电网对新能源的接纳能力。鉴于储能发展的必要性以及分布式光伏储能项目面临的成本和经济性问题,建立分布式光伏储能系统全寿命周期的综合效益评估模型。该模型从项目成本、年收益、总利润和静态投资回收期等方面研究了分布式光伏储能系统的经济性,并从配电网改造和备用成本等方面评估了项目的社会整体效益。算例结果表明,分布式光伏储能系统发电自用率高,年净收益增长明显,其经济性对上网电价和度电补贴的依赖较小。随着光伏和储能技术的发展成熟,无储能系统将不再具备经济性优势,分布式光伏储能系统拥有更大的发展潜力。最后,结合国外可再生能源的发展经验,从社会效益回馈用户、电价激励和金融支持等角度提出了政策和激励建议,以促进分布式光伏行业的健康发展。     

Photovoltaic–Pyroelectric Coupled Effect Induced Electricity for Self‐Powered Photodetector System

Ferroelectric materials have demonstrated novel photovoltaic effect to scavenge solar energy. However, most of the ferroelectric materials with wide bandgaps (2.7–4 eV) suffer from low power conversion efficiency of less than 0.5% due to absorbing only 8–20% of solar spectrum. Instead of harvesting solar energy, these ferroelectric materials can be well suited for photodetector applications, especially for sensing near‐UV irradiations. Here, a ferroelectric BaTiO₃ film‐based photodetector is demonstrated that can be operated without using any external power source and a fast sensing of 405 nm light illumination is enabled. As compared with photovoltaic effect, both the responsivity and the specific detectivity of the photodetector can be dramatically enhanced by larger than 260% due to the light‐induced photovoltaic–pyroelectric coupled effect. A self‐powered photodetector array system can be utilized to achieve spatially resolved light intensity detection by recording the output voltage signals as a mapping figure.     

高效非成像聚光光学系统设计与性能分析

针对菲涅尔透镜存在实际光学效率偏低的问题,本文设计了一种由非球面透镜和棒锥镜组成的高效非成像聚光光学系统。在光学设计软件Zemax的序列模式下对非球面透镜进行了优化设计,通过最大程度地减小球差,像面光斑的几何半径从42 mm降到了1.7 mm。基于此,在Zemax的非序列模式下,完成了非球面透镜和棒锥镜的建模和优化,通过蒙特卡罗光线追迹分析实现了光学效率为87%、接收角为0.9°的非成像聚光光学系统。最后,基于非球面透镜阵列和棒锥镜样品,实现了高倍聚光型光伏模组的封装与测试。测试结果表明,该模组的光电转换效率达30.03%,与菲涅尔透镜构成的高倍聚光型光伏模组相比有显著提升。     

Polymer Photovoltaics with Alternating Copolymer/Fullerene Blends and Novel Device Architectures

The synthesis of novel conjugated polymers, designed for the purpose of photovoltaic energy conversion, and their properties in polymer/fullerene materials and photovoltaic devices are reviewed. Two families of main‐chain polymer donors, based on fluorene or phenylene and donor–acceptor–donor comonomers in alternating copolymers, are used to absorb the high‐energy parts of the solar spectrum and to give high photovoltages in combinations with fullerene acceptors in devices. These materials are used in alternative photovoltaic device geometries with enhanced light incoupling to collect larger photocurrents or to enable tandem devices and enhance photovoltage.     

Coupling of light into nanowire arrays and subsequent absorption

We present a theoretical study of the absorption of light in periodic arrays of InP nanowires. The absorption in the array depends strongly on the diameter and the length of the nanowires, as well as the period of the array. Nanowires of a length of just 2 microm are able, after an appropriate choice for the other parameters, to absorb more than 90% of the incident energy of TE and TM polarized light, with photon energies almost all the way down to the band gap energy and an incidence angle up to 50 degree. This high total absorption arises from a good coupling of the incident light into the nanowire array at the top interface between air and the array and absorption inside the array before the light reaches the interface between the nanowires and the substrate. We find that for a given photon energy there exists a critical nanowire diameter above which a dramatic increase in the absorption occurs. The critical diameter decreases for increasing photon energies, and is directly related to the dispersion of waveguiding modes in single isolated nanowires. A characterization showed that the absorption characteristics of the nanowire arrays are very promising for photovoltaic applications.     

Is floating photovoltaic better than conventional photovoltaic? Assessing environmental impacts

Photovoltaic (PV) solar energy installations are growing all over the world as a promising renewable alternative to generate electricity. However, many studies have highlighted some drawbacks associated with the installation and operation of conventional solar energy power plants. Thus, floating photovoltaic (FPV) systems have been emerging as a new concept in solar energy to lessen negative environmental impacts caused by allocation of conventional PV facilities. This paper is an overview of the potential negative and positive environmental impacts caused by photovoltaic systems with particular interest on large-scale conventional and floating photovoltaic. This study addresses and compares the impacts at all phases of project implementation, which covers planning, construction, and operation and decommissioning, focusing on ambient located in the tropics. The overall impacts associated with project allocation such as deforestation (for the project implementation and site accessing), bird mortality, erosion, runoff, and change in microclimate are expected to have higher magnitudes for the implementation of conventional PV facilities. The results highlight advantages of FPV over conventional PV during the operational and decommissioning phases as well. Though, further studies are required to assess both qualitative and quantitative aspects of installations in similar areas.     

Influence of annealing on principal photovoltaic parameters of perylenetetracarboxylate/MEH-PPV solar cells

A novel perylenetetracarboxylate, tetra-benzyl perylene-3,4,9,10-tetracarboxylate (TBEP), was synthesized and acted as an acceptor used in polymer photovoltaic devices. Photovoltaic devices of ITO/PEDOT-PSS/MEH-PPV+TBEP/Ba/Al were fabricated and their photovoltaic parameters were measured. The photophysics of the blend material and the effects of annealing on performance and morphology of these devices were discussed. Annealing process resulted in the formation of TBEP crystal network, which increases the external quantum efficiency (EQE) and energy conversion efficiency (ηe) of the photovoltaic devices.