Comparative Study of Solar PV Power Plant Dimensionnement Connected to Network Based on Monofacial and Bifacial Modules

This article presents the results of comparative study of two PV solar modules technologies,namely monofacial and bifacial.This study main objective is to identify conditions and parameters that make it possible to obtain better energy and economic efficiency from one or other of two technologies.The study reason lies in revival observed on bifacial module in recent years where all the major manufacturers of PV solar panels are developing them where in a few years,this technology risks being at the same price as the monofacial solar panel with better efficiency.Economic indicator used is energy levelized cost(LCOE)which is function technology type,energy productivity,annual investment and operation cost.To achieve this,a 3.685 MWc solar PV power plant was dimensioned and simulated under Matlab for a 3.5 ha site with a 2,320,740,602 FCFA budget for monofacial installation,against 1,925,188,640 FCFA for 2.73 MWc bifacial installation.The LCOE comparative analysis of two technologies calculated over a period of 25 years,showed that plant with bifacial panels is more beneficial if bifacial gain is greater than 9%.It has further been found that it is possible to gain up to 40%of invested cost if bifacial gain reaches 45%.Finally,a loss of about 10%of invested cost could be recorded if bifacial gain is less than 9%.

Multimodel Ensemble Forecast of Global Horizontal Irradiance at PV Power Stations Based on Dynamic Variable Weight

In the present study,multimodel ensemble forecast experiments of the global horizontal irradiance(GHI)were conducted using the dynamic variable weight technique.The study was based on the forecasts of four numerical models,namely,the China Meteorological Administration Wind Energy and Solar Energy Prediction System,the Mesoscale Weather Numerical Prediction System of China Meteorological Administration,the China Meteorological Administration Regional Mesoscale Numerical Prediction System-Guangdong,and the Weather Research and Forecasting Model-Solar,and observational data from four photovoltaic(PV)power stations in Yangjiang City,Guangdong Province.The results show that compared with those of the monthly optimal numerical model forecasts,the dynamic variable weight-based ensemble forecasts exhibited 0.97%-15.96%smaller values of the mean absolute error and 3.31%-18.40%lower values of the root mean square error(RMSE).However,the increase in the correlation coefficient was not obvious.Specifically,the multimodel ensemble mainly improved the performance of GHI forecasts below 700 W m-2,particularly below 400 W m-2,with RMSE reductions as high as 7.56%-28.28%.In contrast,the RMSE increased at GHI levels above 700 W m-2.As for the key period of PV power station output(02:00-07:00),the accuracy of GHI forecasts could be improved by the multimodel ensemble:the multimodel ensemble could effectively decrease the daily maximum absolute error(AE max)of GHI forecasts.Moreover,with increasing forecasting difficulty under cloudy conditions,the multimodel ensemble,which yields data closer to the actual observations,could simulate GHI fluctuations more accurately.

PV Capacity Evaluation Using ASTM E2848: Techniques for Accuracy and Reliability in Bifacial Systems

A variety of test methodologies are commonly used to assess if a photovoltaic system can perform in line with expectations generated by a computer simulation. One of the commonly used methodologies across the PV industry is an ASTM E2848. ASTM E2848-13, 2023 test method provides measurement and analysis procedures for determining the capacity of a specific photovoltaic system built in a particular place and in operation under natural sunlight. This test method is mainly used for acceptance testing of newly installed photovoltaic systems, reporting of DC or AC system performance, and monitoring of photovoltaic system performance. The purpose of the PV Capacity Test and modeled energy test is to verify that the integrated system formed from all components of the PV Project has a production capacity that achieves the Guaranteed Capacity and the Guaranteed modeled AEP under measured weather conditions that occur when each PV Capacity Test is conducted. In this paper, we will be discussing ASTM E2848 PV Capacity test plan purpose and scope, methodology, Selection of reporting conditions (RC), data requirements, calculation of results, reporting, challenges, acceptance criteria on pass/fail test results, Cure period, and Sole remedy for EPC contractors for bifacial irradiance.

Analysis for Effects of Temperature Rise of PV Modules upon Driving Distance of Vehicle Integrated Photovoltaic Electric Vehicles

The development of vehicle integrated photovoltaics-powered electric vehicles (VIPV-EV) significantly reduces CO2 emissions from the transport sector to realize a decarbonized society. Although long-distance driving of VIPV-EV without electricity charging is expected in sunny regions, driving distance of VIPV-EV is affected by climate conditions such as solar irradiation and temperature rise of PV modules. In this paper, detailed analytical results for effects of climate conditions such as solar irradiation and temperature rise of PV modules upon driving distance of the VIPV-EV were presented by using test data for Toyota Prius and Nissan Van demonstration cars installed with high-efficiency InGaP/GaAs/InGaAs 3-junction solar cell modules with a module efficiency of more than 30%. The temperature rise of some PV modules studied in this study was shown to be expressed by some coefficients related to solar irradiation, wind speed and radiative cooling. The potential of VIPV-EV to be deployed in 10 major cities was also analyzed. Although sunshine cities such as Phoenix show the high reduction ratio of driving range with 17% due to temperature rise of VIPV modules, populous cities such as Tokyo show low reduction ratio of 9%. It was also shown in this paper that the difference between the driving distance of VIPV-EV driving in the morning and the afternoon is due to PV modules’ radiative cooling. In addition, the importance of heat dissipation of PV modules and the development of high-efficiency PV modules with better temperature coefficients was suggested in order to expand driving range of VIPV-EV. The effects of air-conditioner usage and partial shading in addition to the effects of temperature rise of VIPV modules were suggested as the other power losses of VIPV-EV.

基于PVsyst的单面与双面光伏组件最佳安装倾角对比

随着光伏发电技术不断进步,单面光伏组件与双面光伏组件的价差不断缩小。得益于发电量增益大,双面光伏组件在实际项目中受到愈来愈多的青睐。当光伏发电项目采用单面或双面光伏组件时,光伏组件的最佳安装倾角成为一个重要的考虑因素。选取了3个太阳能资源等级地区,利用PVsyst对在这3个地区建设的光伏电站分别采用单面和双面光伏组件时的安装倾角与光伏电站首年发电量及光伏组件正面接收的太阳辐照量之间的关系进行了仿真模拟。得到以下结论:1)以光伏电站首年发电量最大为衡量标准时,双面光伏组件的最佳安装倾角大于或等于有阴影遮挡的单面光伏组件的最佳安装倾角,但小于无阴影遮挡的单面光伏组件的最佳安装倾角。2)就单面光伏组件而言,无阴影遮挡条件下增加光伏组件安装倾角带来的发电量增益高于有阴影遮挡安装条件时。3)在无阴影遮挡情况下,在一定范围内增大单面光伏组件的安装倾角可以相应提升其发电量;相对于双面光伏组件,无阴影遮挡的单面光伏组件通过适当提高其安装倾角所获得的发电量增益较小,且增大安装倾角,光伏阵列之间的间距也需要相应增加,这会增大用地量,从而增加项目总成本。因此,在实际项目中,尽可能采用双面光伏组件是一个较为理想的选择。

基于PVLIB的光伏组件串联数量计算条件及方法分析

为得到更为高效且合理的光伏组件串联数量的计算条件和计算方法,选取位于不同纬度、不同气候类型的119个拟定项目地点,基于PVLIB和NASA的气象数据获取119个拟定项目地点的20年逐小时气象数据,对采用不同计算条件时得到的光伏组件开路电压及其对应的光伏组件串联数量进行了分析。分析结果显示:基于200 W/m^(2)太阳辐照度及历史最低气温计算得到的光伏组件串联数量与基于多年逐时气象数据计算得到的光伏组件串联数量结果相近,且计算方法较为简便,不需要长序列逐时气象数据,可用于光伏电站设计中光伏组件串联数的计算条件。

基于PVsyst的倾角可调固定式光伏支架的调节次数及倾角偏差影响分析

以位于内蒙古自治区的采用倾角可调固定式光伏支架的某光伏电站为例,首先利用PVsyst软件对不同光伏支架倾角下的年发电量进行模拟,得到最佳倾角;然后对光伏支架倾角的浮动范围进行分析;最后针对倾角可调固定式光伏支架的调节时间及调节次数进行研究,并分析1年调节2次倾角时倾角偏差对发电量的影响。研究结果显示:1)相对于全年采用最佳倾角固定式光伏支架的光伏电站,光伏支架倾角年调节次数由2次增加到12次,光伏电站年发电量增益可由4.72%增至5.81%。2)光伏支架倾角调节次数与季节无直接相关性;相对于全年采用最佳倾角固定式光伏支架的光伏电站,随着光伏支架倾角调节次数的增加,光伏电站的年发电量增益逐渐增加,但增幅在逐渐减小。3)在确定光伏支架年调节次数时,需要综合考虑发电量的增益和需要投入的成本,选择2~4次较为合适。4)倾角可调固定式光伏支架1年调节2次倾角时,每次倾角可允许存在±5°的偏差范围,且综合考虑现场工况和调节精度等实际情况后,年理论发电量的最大损失率仅约为0.3%。以期研究结果可为光伏电站的光伏支架倾角设计方案比选、运维时的倾角调节优化及技术标准制定等工作提供参考。

基于PVsyst软件模拟发电量数据的光伏电站电能损耗的分析方法研究

电能损耗是光伏电站非常重要的综合性指标,对其进行分析可以为光伏电站能效管理提供数据支持。在电能损耗的计算过程中,最大负荷损耗小时数的选取非常关键。提出了一种基于PVsyst软件模拟所得的发电量数据来分析光伏电站电能损耗的方法,结合工程实际情况给出了精确计算年最大负荷损耗小时数的改进算法数学模型,并对采用不同算法得到的年最大负荷损耗小时数进行了比较分析;以山西省大同市鸦儿崖乡100 MW光伏电站为算例,对其电气设备及线缆的电能损耗进行详细分析,验证了所提出光伏电站电能损耗分析方法的正确性。研究结果表明:1)由于光伏电站容配比的影响,应分别计算光伏电站直流侧和交流侧的年最大负荷损耗小时数,直流侧和交流侧的电能损耗也需要分别计算。2)该方法基于PVsyst软件模拟得到的光伏电站全年各小时的发电量数据,可准确计算出光伏电站的年最大负荷损耗小时数,在数学逻辑上合理,可以提高光伏电站电能损耗计算的准确度。该方法也可应用于其他实际运行的发电项目的电能损耗分析。

基于PVsyst的光伏系统研究

基于PVsyst软件,以吐鲁番地区某民居为模拟对象,对当地的气象数据进行分析,并构建了一套安装在屋顶的光伏并网发电系统。对光伏并网系统的安装倾角进行优化,并对光伏组件进行选型,对系统损失进行分析。最后根据模拟结果,对影响系统发电效率的因素进行分析并提出了一些优化方案,以及得出吐鲁番地区19.1 kW的光伏并网系统全年发电量为27.9 MW·h,系统效率为80.9%,能量回收期为2.98年,每年可减少32790 kg的CO_(2)排放量,具有一定的环境效益;若按新疆光伏上网电价0.262元(/kW·h)进行计算,每年还可带来7309.8元的收入。该研究对实际光伏并网系统的设计施工具有一定的参考意义。

基于PVsyst的“跟踪支架+双面组件”光伏发电系统的发电量评估方法研究

以内蒙古自治区鄂尔多斯地区某个拟转移所有权的新建光伏领跑者项目为例,对双面光伏组件分别与平单轴和斜单轴跟踪支架结合时光伏发电系统第0年的理论上网电量进行分析,进而得到该项目寿命期内各年的理论上网电量、等效满负荷利用小时数,以及25年的理论年平均上网电量和年平均等效满负荷利用小时数。结果显示:计算得到的项目年平均等效满负荷利用小时数低于可研设计值,高于根据实际上网电量测算得到的值。以期可为项目收购决策和经济性分析提供科学参考及依据。

BAPV并网发电系统的实验研究

以BAPV并网发电实验系统为研究平台,探讨建筑屋顶上太阳电池阵列的简易安装方法,对系统的实际运行特性进行了全面的实验研究。通过检测电气变量和采集全年运行数据,讨论系统的电能质量问题,比较3种不同类型太阳电池在南方湿热地区的实际发电能力,验证影响发电效率的要因。全年发电特性的统计数据不仅为系统的设计确立了重要的技术参考指标,也为成本与效益的评估、相关标准和政策的制订提供了有价值的实验依据。

一种新型PV AC Module的研究

为了解决传统的两级式光伏交流模块PV AC module存在的结构复杂、成本高、效率低等问题,提出了一种新型PV AC module。该AC module的前级为传统的Boost变换器,完成光伏组件的最大功率点跟踪和光伏接口电压的泵升;后级采用高增益集成式逆变器,实现直流母线电压的泵升和并网发电功能。分析了PV AC module的系统结构,工作原理及控制策略,并通过一套250 W/40 kHz的样机仿真模型,验证了方案的可行性与理论分析的正确性。研究结果表明:该新型PV AC module具有结构简洁、控制简单、成本低、效率高等优点。

基于变步长功率跟踪的有功备用式PV-VSG控制策略

传统光伏发电系统多以最大功率跟踪方式并网,不具备有功调频能力,而将其改造的光伏虚拟同步发电机多以配备储能的方式实现虚拟同步功能,但储能设备过于昂贵,主电路改造成本较大。针对上述问题,在不改造传统集中式光伏逆变器主电路的情况下,提出一种基于变步长功率跟踪的有功备用式光伏虚拟同步发电机策略,通过有功备用方式实现虚拟同步功能,节省改造成本,所提方法克服了固定步长跟踪方法快速性和稳定性不能兼容的问题,并且使光伏虚拟同步发电机快速精确地提供惯性及阻尼支撑控制。仿真结果验证了所提控制策略的有效性。

Numerical modeling of all-day albedo variation for bifacial PV systems on rooftops and annual yield prediction in Beijing

Bifacial PV modules capture solar radiation from both sides,enhancing power generation by utilizing reflected sunlight.However,there are difficulties in obtaining ground albedo data due to its dynamic variations.To address this issue,this study established an experimental testing system on a rooftop and developed a model to analyze dynamic albedo variations,utilizing specific data from the environment.The results showed that the all-day dynamic variations in ground albedo ranged from 0.15 to 0.22 with an average of 0.16.Furthermore,this study evaluates the annual performance of a bifacial PV system in Beijing by considering the experimental conditions,utilizing bifacial modules with a front-side efficiency of 21.23%and a bifaciality factor of 0.8,and analyzing the dynamic all-day albedo data obtained from the numerical module.The results indicate that the annual radiation on the rear side of bifacial PV modules is 278.90 kWh/m^(2),which accounts for only 15.50%of the front-side radiation.However,when using the commonly default albedo value of 0.2,the rear-side radiation is 333.01 kWh/m^(2),resulting in an overestimation of 19.40%.Under dynamic albedo conditions,the bifacial system is predicted to generate an annual power output of 412.55 kWh/m^(2),representing a significant increase of approximately 12.37%compared to an idealized monofacial PV system with equivalent front-side efficiency.Over a 25-year lifespan,the bifacial PV system is estimated to reduce carbon emissions by 8393.91 kgCO_(2)/m^(2),providing an additional reduction of 924.31 kgCO_(2)/m^(2)compared to the idealized monofacial PV system.These findings offer valuable insights to promote the application of bifacial PV modules.

基于PVsyst软件的屋顶光伏发电系统发电量的研究

以郑州市某农村房屋的屋顶为基础,建立小型的屋顶光伏发电系统模型,通过对光伏组件安装倾角和光伏阵列间距进行优化设计,并利用PVsyst软件模拟中国5个地区的屋顶光伏发电系统的单位屋顶面积的年光伏发电量。模拟结果显示:在光伏组件采用最佳安装倾角的前提下,与杭州、广州、昆明这3个城市不同的是,沈阳市的屋顶光伏发电系统采用3.3 m光伏阵列间距时的单位屋顶面积年光伏发电量高于其采用最佳光伏阵列间距时的发电量。由此可知,小型屋顶光伏发电系统发电量最大时的设计并非是在光伏组件最佳安装倾角和最佳光伏阵列间距同时满足的情况下。因此,在进行屋顶光伏发电系统发电量最大化设计时,还应根据屋顶面积进行光伏组件安装倾角和光伏阵列间距的综合考虑。

CIGS-BIPV示范建筑的日发电性能分析

以惠州市潼湖科技创新小镇的铜铟镓硒建筑光伏一体化(CIGS-BIPV)示范项目为例,对该示范项目中示范建筑不同朝向立面上的铜铟镓硒(CIGS)薄膜光伏组件在夏季、冬季典型日的发电量特点和变化规律进行分析,结果显示:1)初夏的5月12日,安装在东南侧、西南侧、东北侧的CIGS薄膜光伏组件的日发电量大体相当,西南侧安装的CIGS薄膜光伏组件与东南侧、东北侧安装的CIGS薄膜光伏组件的日发电量曲线大致呈镜像关系。2)初冬的11月22日,安装在东南侧、西南侧的CIGS薄膜光伏组件的日发电量大体相当,均是安装在东北侧的CIGS薄膜光伏组件的约3倍。3)安装在东南侧、西南侧的CIGS薄膜光伏组件在11月22日的高效率发电时长高于其在5月12日的,发电量更大;安装在东北侧的CIGS薄膜光伏组件在5月12日的发电量是在11月22日的2.5倍。该研究结果可为采用薄膜光伏组件的BIPV项目和低纬度沿海地区的光电建筑应用提供借鉴。

ENGAGE^TM PV POE胶膜对双面光伏组件长期可靠性的影响

通过实验分析了聚烯烃弹性体(POE)胶膜、聚乙烯醋酸乙烯酯(EVA)胶膜及ENGAGETM PV POE胶膜的特性。实验结果显示,ENGAGETM PV POE胶膜由于优异的电绝缘性和低水汽透过率,可以助力提高双面光伏组件的抗电势诱导衰减(PID)性能,以达到延长组件使用寿命及降低度电成本的目的。

Study and Design of a DC/AC Energy Converter for PV System Connected to the Grid Using Harmonic Selected Eliminated (HSE) Approach

Nowadays, distributing network-connected photovoltaic (PV) systems are expanded by merging a PV system and a Direct Current (DC)/Alternating Current (AC) energy converter. DC/AC conversion of PV energy is in great demand for AC applications. The supply of electrical machines and transfer energy to the distribution network is a typical case. In this work, we study and design a DC/AC energy converter using harmonic selective eliminated (HSE) method. To this end, we have combined two power stages connected in derivation. Each power stage is constituted of transistors and transformers. The connection by switching of the two rectangular waves, delivered by each of the stages, makes it possible to create a quasi-sinusoidal output voltage of the inverter. Mathematical equations based on the current-voltage characteristics of the inverter have been developed. The simulation model was validated using experimental data from a 25.2 kWp grid-coupled (PV) system, connected to Gridfit type inverters. The data were exported and implemented in programming software. A good agreement was observed and this shows all the robustness and the technical performances of the energy converter device. It emerges from this analysis that the inverter output voltage and the phase angle thus simulated are very important to control in order to orientate the transfer of the power flow from the continuous cell to cell to the alternating part. Simulated and field-testing results also show that increases in the value of the modulation factor (m) for low power output are highly significant. This study is an important tool for DC/AC inverter designers during initial planning stages. A short presentation of the design model of the inverter has been proposed in this article.

2023年中国光伏技术进展综述

2023年中国光伏技术发展迅速,从晶体硅、硅片、晶体硅太阳电池及其光伏组件、薄膜太阳电池及其光伏组件、新型太阳电池、光伏发电系统集成与应用、光伏功率变换器及平衡部件、光伏电站全生命周期数智化技术、光伏发电标准及实证测试、太阳电池光电转换效率等方面对2023年中国光伏技术发展情况进行了系统总结,客观描绘了中国光伏技术创新地图全貌。得到以下结论:1)三氯氢硅法(改良西门子法)和硅烷法技术的能耗指标达到国际先进水平,多次装料拉晶(RCz)技术仍是主要的硅棒生产方式,结合颗粒硅料的连续直拉单晶(CCz)技术持续取得进展。2)n型太阳电池的市场份额快速增加,TOPCon太阳电池大规模量产,HJT太阳电池产能持续增加,BC太阳电池实现批量生产。晶体硅太阳电池、钙钛矿太阳电池、钙钛矿/硅叠层太阳电池、CZTSSe薄膜太阳电池、有机太阳电池等太阳电池的光电转换效率屡创世界纪录。3)多层次立体化光伏发电应用体系不断丰富,大型地面光伏电站、分布式光伏电站、海上漂浮式光伏电站、天基/空间光伏发电系统、山地光伏电站等多元化应用模式蓬勃发展。

面向光伏电站除尘作业的移动机械臂抗倾覆稳定性研究

对光伏电站移动机械臂倾覆稳定性的研究是其安全、高效作业的前提。采用重力法分析移动机械臂在水平路面和倾斜路面的静态稳定性,以倾覆力矩为标识对移动平台与机械臂耦合状态下的稳定性进行分析,并利用Matlab和Adams仿真验证移动机械臂的稳定性,结果表明移动机械臂在水平路面上进行作业运动时处于稳定状态;通过分析移动机械臂在倾斜路面上的稳定性,确定其可安全操作的最大路面倾斜角度。