南极中山站30 kW光伏发电系统工作特性研究

研究南极中山站地区太阳辐照度和环境温度的联合分布情况,确定极端环境条件;建立不同辐照度和温度条件下光伏电池I-V特性分析模型,分析极端条件对电池发电特性的影响;研究确定2种30 kW光伏发电阵列方案,并对光伏阵列的发电性能进行仿真分析。研究结果:极区环境对光伏组件的发电特性有较大影响,在倾角、辐照度和环境温度等因素影响下,光伏组件的开路电压、最大功率电压能够增大16.9%,短路电流、最大功率电流增大31%,瞬间最大功率可能增大50.2%。     

灰层遮挡对n型双面光伏组件发电量的影响

在连云港地区搭建光伏阵列试验平台,研究对比清洁组件与灰层遮挡组件的长期发电量差异,研究灰层遮挡对n型双面组件和p型单玻组件发电性能等的影响。研究表明:灰层遮挡对n型双面组件发电量的影响程度低于p型单玻组件,表面清洁状态下,p型单玻组件和n型双面组件发电量平均增益分别为3.2%和1.7%;地面反射率越高,n型双面组件受灰层遮挡影响的程度越低;相同灰层遮挡条件下,n型双面组件工作温度低于p型单玻组件。     

异质结光伏组件的发电效果研究

为研究异质结光伏组件的实际发电效果,收集某光伏发电站近两年的发电量数据,得到单块组件的月均发电量.通过对比分析,验证该异质结光伏组件相对于多晶光伏组件在发电效率方面的优越性,且与理论增益相符.通过计算冬夏两季的月均发电量和月均辐照度,证明相比多晶光伏组件,温度升高对该异质结光伏组件的功率影响更小,与理论上异质结光伏组件...     

单面和双面单晶硅光伏组件的发电性能实证

针对p型PERC单面单晶硅光伏组件和n型双面单晶硅光伏组件,利用光伏组件户外实证测试系统,分析了2016年12月15日~2018年7月20日期间,上海市嘉定区某屋顶的地面采用白板背景时双面和单面组件,以及水泥背景时双面组件的等效发电时长,并对白板背景和水泥背景时双面组件较单面组件的发电量增益情况进行了分析;计算了组件的PR值;分析了阴天和晴天时组件最大输出功率与组件背板温度、太阳辐照度和环境温度的关系;最后对比了单面和双面组件运行13个月后的衰减值。该实证结果为单面和双面组件的户外实证发电性能提供了数据支撑,并对双面组件较单面组件的发电量增益情况进行了有效证明。     

基于组件输出功率估算的光伏电站经济效益研究

基于辐照度、温度等环境因素对光伏组件输出功率的影响程度,建立了光伏组件输出功率估算模型,对光伏电站的总装机成本、运营成本及收益进行了分析,给出了光伏电站项目的现金流,并选择内部收益率指标和净现值法,分析了光伏电站的经济效益,推导出期望内部收益率下的光伏电站成本、规模与发电量之间的匹配模型,提出了经济发电量和环境约束发电量的概念。通过算例对比分析两种发电量的差异,验证了模型的有效性和实用性,为光伏电站的选址和装机容量的选择提供了决策依据。     

光伏组件选型对光伏系统发电量的影响

深入研究了不同种类光伏组件在不同天气条件下的发电特性以及相同种类不同厂家光伏组件的发电特性。实验结果表明不同种类太阳电池在不同季节的发电特性存在明显差异。晶体硅和CIGS(铜铟镓硒)电池冬季发电量明显高于硅薄膜电池,最多可多发电10%左右;随时间推移,三者之间的差异先逐渐减小后增加,到夏季硅薄膜反超多晶硅和CIGS,最多可多发电20%左右。同时,结合光辐照度、温度、湿度等天气资料,测试结果表明:晶体硅和CIGS更适合辐照量高、温度低、湿度小的中国北部地区;硅薄膜在辐照度不高、温度高、湿度大的中国南部大部分地区具有更高发电量。     

PV/T-SAHP系统实验研究

通过系统在不同运行模式下的实验研究,分析太阳辐照度、温度等参数对系统光伏光热性能的影响,结果表明光伏热泵组件发电效率比传统光伏组件提高16.4%;在获得同样热水情况下,混联运行比串联运行每天多输出1.7 k Wh的净发电量,热泵平均COP从1.9升高到3.4。间接式光伏热泵系统将集热器的热量在蒸发器与冷凝器间进行合理分配后,比直膨式光伏热泵系统具有更好的综合性能。     

基于石墨烯提升光伏组件散热性能实验研究

采用新型石墨烯材料用于光伏组件背板散热,以提高光伏组件能量转换效率。在硅太阳电池组件基础上分别设计并制作普通石墨烯薄膜组件以及石墨烯肋片复合结构组件,建立2种石墨烯光伏组件的热力学模型,搭建石墨烯组件散热性能测试平台进行实验研究,此外进行组件室外光伏电站的性能测试。实验结果表明,添加石墨烯及肋片能增强光伏组件散热性能和提高组件输出功率;在室内模拟的晴天气象条件及辐照度高的情况下,石墨烯肋片复合组件的散热性能提升较为显著。通过室外测试,石墨烯肋片复合组件的功率及发电量相比于普通光伏组件分别提高0.5%～1.15%和0.97%。     

采用双面光伏组件的光伏电站在系统集成设计中应考虑的因素分析

采用双面光伏组件是一种能够有效提升光伏电站发电量的手段。基于双面光伏组件的特点,通过列举行业内常用的双面光伏组件辐照度数学模型,对影响双面光伏组件发电量的地面反射率、前后排光伏阵列间距、光伏组件最佳安装倾角和光伏组件离地高度这几个主要因素进行了研究,并通过PVsyst软件对这几个主要因素进行了逐一仿真验证,从实际应用角度提出了采用双面光伏组件的光伏电站在系统集成设计中应考虑的几个因素。研究结果表明：1)双面光伏组件的最佳安装倾角比单面光伏组件的最佳安装倾角大,根据地区、地面反射率的不同,二者的差值大致在2°～10°之间;2)提高光伏组件离地高度可以增加双面光伏组件的发电量,而发电量增益大小会因光伏组件所在地纬度的不同有所不同,实际光伏电站的系统集成设计中,可选择最具经济性的光伏组件离地高度;3)在光伏组件最佳安装倾角过低的地区,光伏组件的自遮挡效应严重,需要根据实际情况选择是否采用双面光伏组件。     

积灰对屋顶光伏电站性能的影响

探讨了积灰问题对屋顶光伏电站电性能和热性能的影响。在积灰的初始阶段,组件的发电量下降得较为明显;同时,积灰并未明显改变组件的温度,表明积灰不会改变光伏电池片实时发电效率。积灰对光伏电站发电量的影响主要表现在组件表面太阳光透过率的变化。     

Improved artificial neural network method for predicting photovoltaic output performance

To ensure the safety and stability of power grids with photovoltaic (PV) generation integration, it is necessary to predict the output performance of PV modules under varying operating conditions. In this paper, an improved artificial neural network (ANN) method is proposed to predict the electrical characteristics of a PV module by combining several neural networks under different environmental conditions. To study the dependence of the output performance on the solar irradiance and temperature, the proposed neural network model is composed of four neural networks, it called multi- neural network (MANN). Each neural network consists of three layers, in which the input is solar radiation, and the module temperature and output are five physical parameters of the single diode model. The experimental data were divided into four groups and used for training the neural networks. The electrical properties of PV modules, including I–V curves, P– V curves, and normalized root mean square error, were obtained and discussed. The effectiveness and accuracy of this method is verified by the experimental data for different types of PV modules. Compared with the traditional single-ANN (SANN) method, the proposed method shows better accuracy under different operating conditions.     

Installation and operation of the first city centre PV monitoring station in the United Kingdom

Recent interest in the application of PV in buildings throughout northern Europe has developed a need for long-term records of the solar resource in urban situations. Previous records have usually been collected from locations quite remote from city centre sites and, furthermore, at hourly sampling frequencies which are not rapid enough for photovoltaic applications. The installation of a photovoltaic monitoring station in a city centre in the north-east of England is described. Weather monitoring instruments were installed to measure ambient temperature, wind speed and direction, relative humidity and solar irradiance. Four types of photovoltaic modules are mounted on the rig in typical buiding orientations in order to assess their performance with respect to PV cladding applications. Preliminary investigations have shown that the electricity generated by PV cladding on vertical surfaces experiences much less seasonal variation than that on a horizontal surface. The performance of north and south facing modules has also been compared and this has shown that the north facing modules generate reasonably large amounts of electricity, particularly during the summer months. The proportion of diffuse irradiance on a north facing surface has been studied and quantified for various amounts of global horizontal irradiance. Analysis of the cadmium telluride modules has confirmed a better response to diffuse irradiance than the silicon modules and records of the amorphous silicon module show no evidence of cell degradation.     

A power-rating model for crystalline silicon PV modules

A model for the performance of generic crystalline silicon photovoltaic (PV) modules is proposed. The model represents the output power of the module as a function of module temperature and in-plane irradiance, with a number of coefficients to be determined by fitting to measured performance data from indoor or outdoor measurements. The model has been validated using data from 3 different modules characterized through extensive measurements in outdoor conditions over several seasons. The model was then applied to indoor measurement data for 18 different PV modules to investigate the variability in modeled output from different module types. It was found that for a Central European climate the modeled output of the 18 modules varies with a standard deviation (SD) of 1.22%, but that the between-module variation is higher at low irradiance (SD of 3.8%). The variability between modules of different types is thus smaller than the uncertainty normally found in the total solar irradiation per year for a given site. We conclude that the model can therefore be used for generalized estimates of PV performance with only a relatively small impact on the overall uncertainty of such estimates resulting from different module types.     

Mapping the performance of PV modules, effects of module type and data averaging

A method is presented for estimating the energy yield of photovoltaic (PV) modules at arbitrary locations in a large geographical area. The method applies a mathematical model for the energy performance of PV modules as a function of in-plane irradiance and module temperature and combines this with solar irradiation estimates from satellite data and ambient temperature values from ground station measurements. The method is applied to three different PV technologies: crystalline silicon, CuInSe₂ and CdTe based thin-film technology in order to map their performance in fixed installations across most of Europe and to identify and quantify regional performance factors. It is found that there is a clear technology dependence of the geographical variation in PV performance. It is also shown that using long-term average values of irradiance and temperature leads to a systematic positive bias in the results of up to 3%. It is suggested to use joint probability density functions of temperature and irradiance to overcome this bias.     

Evaluation of the impact of solar spectrum and temperature variations on output power of silicon-based photovoltaic modules

Various types of silicon-based photovoltaic modules were installed at the same outdoor exposure site in Japan. The output parameters of the modules were measured and also incident irradiance, incident spectrum, and module temperature were recorded at the same time. A statistical analysis method has been proposed to separate the influences of spectrum variations and module temperature variations on the output performance of the modules. Moreover, with this method, the performance of polycrystalline silicon, amorphous silicon, and three-stacked amorphous silicon photovoltaic modules were analyzed.     

基于天空辐射冷却系统的光伏组件降温研究

在南北向相邻两排光伏组件之间,背阳设置天空辐射冷却模块,不仅可有效利用屋顶面积,还可提升辐射冷却性能。辐射冷却模块产生的冷量通过水系统作用于光伏组件背面的换热模块,对光伏组件进行降温,提升光伏发电效率,延长使用寿命。实验结果表明：该系统在夏季和秋季可分别使光伏组件日平均温度降低13.6℃和10.6℃,发电效率可分别提升1.21%和0.96%。     

双面光伏组件发电性能影响因素理论与实验研究

基于视角系数模型,理论计算与实验分析双面光伏组件的背面辐照度分布,根据组件背面的辐照度模型和太阳电池等效电路的单二极管模型,采用I-V曲线叠加法计算其微失配损耗;并提出简化反射光谱模型准确计算反射太阳光谱,以光谱失配因子量化反射光谱对双面组件背面发电性能的影响,结合组件背面辐射视角系数模型,建立双面组件背面功率输出的计...