晶体硅光伏组件不同单列布置方案下的串联接线方式优化研究

主要研究了光伏组件在单列支架上不同布置方式时的串联接线方案,结合工程实际应用,对目前西北高原地区大型地面并网光伏电站常用的72片大型光伏组件、60片小型光伏组件在横向、竖向布置,长、短支架布置排列组合共8种布置方案下的串联接线方案进行详细分析,并发现光伏组件竖向布置时的奇偶交叉串联接线方式,可有效解决光伏组件串联过程中因组件出厂时自带的接线盒出线电缆长度不够而导致现场需要在串联的每2块光伏组件中增加电缆才能解决串联接线的麻烦。研究对光伏发电系统设计、光伏组件生产工艺,以及工程实际应用中缩短施工周期、保证工程质量、节省建设成本、综合提升光伏发电系统效率都有实际指导意义。     

50 MW_p并网光伏电站发电系统的设计研究

根据宾川县西村光伏电站一期50 MWp的实际情况,分析出并网光伏发电系统在宾川县具有可行性,通过对多种光伏组件的型式、组件安装及运行方式,以及逆变器的选型,设计出了比较合理的光伏阵列、电气部分(即电气系统一次部分、二次部分、防雷措施的设计研究)等。通过研究表明,并网光伏发电综合价值很高,在地理条件适宜、光照充足的地区可以建设并网光伏电站工程,可从根本上把本地的太阳能资源优势转变为经济优势。     

光伏组件对阴影敏感度的测试及分析应用

针对光伏电站组件的布置方式,给出光伏组件防反二极管连接方式的测试方法,并应用于平整度不同的场地及不同布置类型的组件。利用专业测试设备,对组件上不同方位阴影遮挡的敏感度进行了现场试验及分析。分析结果表明,防反二极管连接方式是影响光伏组件对阴影敏感度的决定性因素。当防反二极管为竖向布置的情况下,场地南北高差为主要影响时,建议组件横向放置;当场地东西高差为主要影响时,建议组件竖向放置。     

100 MWp并网光伏电站节能优化设计

文中针对大量新建大型并网光伏电站并网系统应用占据主要地位的状况,从设计角度出发,探讨并网光伏电站节能措施。文中结合金昌新阳光100 MWp并网光伏电站工程实例,从光伏组件选择、光伏组串设计、光伏组件安装方式、光伏组件的最佳倾角、光伏方阵间距、光伏方阵电缆排布等方面对100 MWp并网光伏电站的节能优化设计进行分析和探讨,以求共同提高设计水平。     

并网光伏电站阵列细化设计

介绍了我国光伏发电发展现状,论述了光伏电站阵列设计中辐照量最大倾角与发电量最大倾角,光伏组件横向排布与竖向排布,光伏组串"C"形接线方式与"一"形接线方式。在此基础上,基于Pvsyst6软件进行建模和仿真,分别对阵列倾角、组件排布及接线形式等主要阵列参数方案进行对比和分析,提出相对更优方案,分析不同方案引起的发电量与系统效率差异原理。     

山地光伏电站的近场阴影模拟研究

结合复杂山地地形条件下光伏组件的布置方案，基于PVsyst软件和Helios 3D软件建立了山地光伏电站三维近场阴影仿真模型，以模拟计算近场阴影遮挡损失修正系数；另外根据项目建设区域内实际的光伏组件倾角和光伏方阵方位角，结合光伏电站朝向替代计算，得到近场阴影遮挡损失修正系数；最后对3种计算方案得到的近场阴影遮挡损失修正系数与该项目实际值进行对比。研究结果表明：由于山地光伏电站项目建设区域地形中的坡度、坡向变化对光伏组件倾角、光伏方阵方位角存在影响，导致山地场景下的近场阴影遮挡损失修正系数比平地场景下的更大。提出的Helios 3D模拟计算方案和公式计算方案同样适用于其他山地光伏电站，可以对特定地形条件下光伏发电系统的阴影情况进行模拟，以评估光伏组件倾角、光伏方阵方位角对近场阴影遮挡损失修正系数的影响，可为精细化评估山地光伏电站中光伏组件布置方案对近场阴影遮挡损失修正系数的影响程度提供合理的分析、研究方案。     

多通道光伏组件测试系统的设计

为解决目前光伏组件测试工作繁冗的问题,研发了一种新型多通道光伏组件测试系统,可为光伏组件的户外性能测试、数据分析及优化布置提供极大地便利,并可为光伏电站的发电效率分析提供精确的测试数据。     

基于新能源集控平台的光伏组件清洗分析系统的设计

灰尘是影响光伏电站发电效率的关键因素之一,其会大幅降低光伏电站的发电量。为降低积灰对光伏电站发电量损失影响的程度,电站需定期清洗光伏组件,因此,基于新能源集控平台设计了一款光伏组件清洗分析系统。该系统通过建立清洗计算模型,提出光伏组件无积灰理论发电量算法,量化了积灰损失发电量,推算光伏组件的最优清洗周期。结果显示：该系统能够为光伏组件清洗提供合理的决策依据。     

资源集约化条件下水面漂浮式光伏发电系统的研究及应用

中国光伏产业蓬勃发展，巨大的光伏市场促进了光伏发电系统效率提升、系统成本下降，给技术改造创造了空间。利用泰和20 MW渔光互补光伏电站原有鱼塘水面已布置光伏组件后剩余的空间进行技术改造，增补了400 kW水面漂浮式光伏发电系统。从光伏组件布置、系统结构设计、建设成本分析等3个方面，对新增光伏发电系统分别采用水面漂浮式光伏发电系统和传统渔光互补光伏发电系统这两种方案的建设结果进行对比分析。结果表明：采用水面漂浮式光伏发电系统可减少建设成本，增加土地利用率。研究结果可为今后相似工程设计提供参考。     

光伏组件与阵列遮挡阴影下的输出特性仿真分析

首先,利用PVsyst模拟了电池板遮挡面积、配置的二极管数目及不同遮挡位置下组件的输出特性,提出了提高光伏组件输出功率的方法;其次,结合长沙某菜市场拟建的光伏电站,利用PVsyst仿真了配置不同的二极管数量及两种布置方式下光伏阵列的输出特性,比较冬至日某个时刻间距阴影遮挡和近处阴影遮挡两种情况下阵列的输出特性。结果表明,对于只有间距阴影遮挡的光伏阵列配置二极管的数量和采用的布置方式对结果的影响非常小;当阵列有严重的近处阴影遮挡时,适当提高配置的二极管数量,PR提高2.3%;竖向布置方式高楼遮挡阴影损失率约为横向布置的1.6倍。     

Performance Estimation of a Latent Heat Thermal Energy Storage System with Different Packing Module Arrangements,Boundary Conditions and Melting Models

In a latent heat thermal energy storage system, the shape of the container for encapsulating the phase change material (PCM) and the arrangement of the PCM vessels within the thermal storage tank have a high influence on the performance of the thermal storage tank. In the present study, a newly designed PCM container was used to investigate the effect of the arrangement of the packing module on the performance of the thermal storage tank. To reflect an actual situation, the system should be modeled using the unconstrained melting model, which includes a density difference between the solid and liquid PCM, and also the convective boundary condition with heat transfer fluid should be applied. The amount of deviation from a real situation was analyzed for simplified models of a constrained melting model and an isothermal boundary condition, which have been commonly used in most previous works. The horizontal arrangement of the packing module showed higher performance than the vertical arrangement. Compared to the unconstrained melting model, the constrained melting model underestimated melting by 50 min and 70 min for the horizontal and vertical arrangements, respectively. Compared to the convective boundary condition, the isothermal boundary condition overestimated melting by 115 min and 100 min for the horizontal and vertical arrangements, respectively.     

阴影遮挡下光伏组件横竖向放置对发电量的影响

为了提高阴影遮挡时光伏组件的发电量,针对横、竖向放置时光伏组件相互遮挡产生的功率损失,建立了光伏组件在阴影遮挡情况下的数学模型,考虑了光伏组件并联旁路二极管的影响,仿真模拟了阴影遮挡下横、竖向放置时光伏组件的输出特性,进而以某地100kW光伏阵列为例,计算了光伏组件在不同摆放方式、不同倾角与间距下的辐射量、年发电量、阴影损失及年平均效率,为光伏电站的初步设计提供了一定的参考价值。     

Assessing the technical and economic performance of building integrated photovoltaics and their value to the GCC society

This paper assesses the technical and economic performance of PV technology integrated into residential buildings in the Gulf Cooperation Council (GCC) countries. It highlights the value of PV electricity for the GCC society from the perspective of consumers, utilities and environment. Through a systematic modelling analysis it is shown that the efficiency of PV system drops by 4–6% due to high range of module temperature and also a change in power output due to high ambient temperatures. Consequently, the outputs of horizontal and vertical PV modules are found to be less than estimates based on standard test conditions. Economically, this study shows that building integrated photovoltaic (BIPV) systems are not viable in GCC countries and cannot compete with conventional electricity sources on a unit cost basis. From a society point of view, however, the integration of PV technology into buildings would have several benefits for the GCC countries, including: first, savings in capital cost due to central power plants and transmission and distribution processes; second, an increase in the exported oil and natural gas used for electricity generation; and third, a reduction in the CO₂ emissions from conventional power plants. When these considerations are taken into account then BIPV should become a feasible technology in GCC countries.     

双面光伏组件背面无遮挡时的发电量研究

针对以常规方式安装双面光伏组件时组件背面存在一定遮挡会影响其发电量这一情况,通过对双面光伏组件分别安装于固定式光伏支架、平单轴跟踪光伏支架时组件背面有、无遮挡,以及背景反射率不同时双面光伏组件的发电量情况进行分析,结果发现,在双面光伏组件背面无遮挡的前提下,当采用平单轴跟踪光伏支架且地面背景为白色时,双面光伏组件的发电...     

An intelligent method for sizing optimization in grid-connected photovoltaic system

This paper presents an intelligent sizing technique for sizing grid-connected photovoltaic (GCPV) system using evolutionary programming (EP). EP was used to select the optimal set of photovoltaic (PV) module and inverter for the system such that the technical or economic performance of the system could be optimized. The decision variables for the optimization process are the PV module and inverter which had been encoded as specific integers in the respective database. On the other hand, the objective function of the optimization task was set to be either to optimize the technical performance or the economic performance of the system. Before implementing the intelligent-based sizing algorithm, a conventional sizing model had been presented which later led to the development of an iterative-based sizing algorithm, known as ISA. As the ISA tested all available combinations of PV modules and inverters to be considered for the system, the overall sizing process became time consuming and tedious. Therefore, the proposed EP-based sizing algorithm, known as EPSA, was developed to accelerate the sizing process. During the development of EPSA, different EP models had been tested with a non-linear scaling factor being introduced to improve the performance of these models. Results showed that the EPSA had outperformed ISA in terms of producing lower computation time. Besides that, the incorporation of non-linear scaling factor had also improved the performance of all EP models under investigation. In addition, EPSA had also shown the best optimization performance when compared with other intelligent-based sizing algorithms using different types of Computational Intelligence.     

Statistical investigation of the optimal averaging time for solar irradiance on horizontal and vertical surfaces in the UK

As output from photovoltaic (PV) panels is closely related to sunlight levels, monitoring solar irradiance levels is crucial for system design and predictive purposes. With advances in PV technology, urban sites at northerly locations, where both horizontal and vertical solar irradiance make significant contributions, are becoming increasingly important. The aim of this paper is to compare solar irradiance for horizontal and vertical orientations and to assess the relative effectiveness of differing averages, from 10 min to 1 h, for use in short-term prediction of solar irradiance levels for a UK site. Vertical and horizontal solar irradiance observations were collected from a monitoring station on the roof of a five-storey building at an urban site in Newcastle-upon-Tyne, UK (latitude 55°N). 10-min data was collected for 13- or 15-day periods in two summers (1994, 1995) and two winters (1993, 1994). Although mean levels for horizontal and vertical irradiance were different, as expected, general patterns were very similar indicating the possibility of predicting vertical irradiance from horizontal at the same location. 10-min, 20-min, 30-min and 1-h averaging times were compared utilising autocorrelation coefficients and ARIMA models to assess the information lost when using longer averaging intervals. For consideration of short-term changes, 10-min averages were most informative whilst hourly averages were substantially poorer.     

Impact of uneven shading and bypass diodes on energy extraction characteristics of solar photovoltaic modules and arrays

Solar photovoltaic (PV) energy is becoming an increasingly important part of the world's renewable energy. In order for effective energy extraction from a solar PV system, this paper investigates I–V and P–V characteristics of solar PV modules and arrays. The paper particularly focuses on I–V and P–V characteristics of PV modules and arrays under uneven shading conditions, and considers both the physics and electrical characteristics of a solar PV system in the model development. The article examines how different bypass diode arrangements could affect maximum power extraction characteristics of a solar PV module or array. It is found in this article that under uneven shading conditions, solar PV cells may perform in very different ways and a solar PV system may exhibit multiple peaks in its P–V characteristics. The study of this article also shows that the arrangement of largely distributed bypass diodes within a PV module could effectively improve efficiency and maximum power point tracking strategies for energy conversion of solar PV systems.     

Calculation of the polycrystalline PV module temperature using a simple method of energy balance

The performance of a photovoltaic module is studied versus environmental variables such as solar irradiance, ambient temperature and wind speed. Two types of simplified models are studied in this paper: a PV module temperature model and a PV module electrical efficiency model. These models have been validated utilizing experimental data from two experiments: a 850 Wp grid connected photovoltaic system and a p-Si module with eight temperature sensors integrated into the module. Both models have been coupled to determine the PV array output power versus the three meteorological parameters. This simple model using a simple energy balance and neglecting the radiation effects is in good agreement with the experimental data.     

光伏电站中光伏组件串联数的新设计思路

在对光伏电站的光伏方阵进行设计时,行业内大部分设计人员在计算光伏组件串联数时往往会忽略"光伏组件工作条件下的极限温度"与"气象极限温度"二者的区别,习惯上采用气象极限温度来计算光伏组件串联数.通过分析光伏组件工作条件下的极限温度与气象极限温度的区别,指出了常规计算时采用气象极限温度取值存在的问题,拓宽了看待光伏组件工作...     

Climate-based empirical model for PV module temperature estimation in tropical environment

The paper proposes new mathematical models to estimating PV module temperature for poly and mono crystalline technologies in tropical climate such as in Malaysia. The developed models are based on measured hourly global solar radiation, ambient temperature, relative humidity, wind speed and module temperature. All data were collected over the year 2009 at GreenTech 92 kWp installed PV system in Selangor, Malaysia. The models were compared using r, MBE, RMSE, and MPE. The results showed that the proposed models give the highest value of correlation coefficient r, and good result when considering statistical indicators i.e. low RMSE, low MBE, and low MPE values. The results show that the proposed regression models have advantages over the conventional approaches for calculating the hourly and day-average PV module temperature, and give the closest results comparing to the actual measurements. The proposed approaches can be used as effective tools for predicting the PV module temperature, whether a simple PV module, open rack system, BIPV installations, or even PV/Thermal collector, in remote and rural locations with no direct measurement equipment. The proposed models can be very useful in studying PV system performance and estimating its energy output.