Promotion of grid-connected photovoltaic systems in Spain: Performance analysis of the period 1998–2008

This paper contributes a critical view of the development of grid-connected photovoltaic systems (GCPVS) in Spain during the period 1998–2008 by looking into the different actions that were intended to promote this technology. The Spanish photovoltaic (PV) sector has undergone bullish development in the recent years, but its underlying factors still lack systematic identification and analysis. Accordingly, this paper collects and presents detailed data for describing this evolution. It also makes a special case of the particular promotion of PV systems on roof and goes further to analyze how these actions have affected GCPVS evolution as well as the magnitude of their impact on its performance. The exponential growth of installed cumulative PV power at the end of this period, which largely exceeded the target set for 2008, is canvassed by building an analogy with feedback control systems. In this approach, market response or the PV power attained is considered as the system output, while the different regulation changes are regarded as control actions aimed at enabling GCPVS to hit the energy target. Such an analysis allows determining the most significant delays and control actions that explain the system's performance. Hence, this study suggests an alternative framework to support the formulation and assessment of energy policy as it puts the emphasis not only on the evolution of the system per se but rather on the performance of the system against the energy target. In this regard, it might contribute to enhance the promotion mechanisms of green technologies.     

Monitoring,modelling and simulation of PV systems using LabVIEW

This paper presents a detailed characterization of the performance and dynamic behaviour of photovoltaic systems by using LabVIEW real-time interface system. The developed software tool integrates several types of instruments into a single system which is able to offer online measurements all data sources and comparison simulation results with monitored data in real-time. Comprehensive monitoring and analyzing of PV systems play a very important role. The proposed method is a low-cost solution to provide fast, secure and reliable system by making the system database-ready for performance analysis of PV systems. The proposed method is also applied to a grid connected PV system in the Centre de Developpement des Energies Renouvelables (CDER) in Algeria. The results show that there is a good agreement between the measured and simulation results values. The integration methodology of robust simulation and monitored data in real-time can be extended to study the fault diagnosis of a PV system.     

Statistical analysis of the performance and simulation of a two-axis tracking PV system

The energy produced by a photovoltaic system over a given period can be estimated from the incident radiation at the site where the Grid Connected PV System (GCPVS) is located, assuming knowledge of certain basic features of the system under study. Due to the inherently stochastic nature of solar radiation, the question “How much energy will a GCPVS produce at this location over the next few years?” involves an exercise of prediction inevitably subjected to a degree of uncertainty. Moreover, during the life cycle of the GCPVS, another question arises: “Is the system working correctly?”. This paper proposes and examines several methods to cope with these questions. The daily performance of a PV system is simulated. This simulation and the interannual variability of both radiation and productivity are statistically analyzed. From the results several regression adjustments are obtained. This analysis is shown to be useful both for productivity prediction and performance checking exercises. Finally, a statistical analysis of the performance of a GCPVS is carried out as a detection method of malfunctioning parts of the system.     

Evaluating the impact of the administrative procedure and the landscape policy on grid connected PV systems (GCPVS) on-floor in Spain in the period 2004–2008: To which extent a limiting factor?

The growth of the Spanish photovoltaic (PV) sector in the period 2004–2008 rendered Spain a prominent place among top worldwide countries. Yet, this growth was rather uneven across the different Spanish regions which raised the interest on the drivers ultimately effecting these disparities. Especially controversial were the arguments about the influence of the administrative procedure and the landscape policy on the development of GCPVS on-floor. This study therefore discloses both two elements and evaluates their impact in a group of PV prominent Spanish regions and Catalonia, the latter used as a benchmark because of its comprehensive and stringent regulation on landscape protection, which was accused by the PV industry of thwarting the development of the GCPVS on-floor. Both quantitative and qualitative analyses were carried out. In particular two indexes were elaborated to determine the consistency of the arguments pointing to the landscape protection policy as a decisive barrier to GCPVS growth. First, when the analysis is made in relative terms, the ranking of PV prominent regions changes and many of the differences vanish. Second, rather than the preeminence of a landscape protection policy what really matters for GCPVS on-floor growth is the administrative procedure and the processing enabling its implementation.     

基于青海地区在运光伏电站监测数据的容配比提升分析

随着光伏发电技术进步,近年来光伏组件价格呈快速下降趋势,于是对早期光伏电站进行大规模的光伏组件扩容翻新有了实质性的经济意义。根据青海地区正在运行的光伏电站的实时监测数据,建立光伏组件-逆变器限电率模型,以度电成本(LCOE)为考核指标,分析在不同扩容工程的工程造价影响下,光伏组件-逆变器容配比(下文简称“容配比”)与LCOE的敏感性关系,以确定在运光伏电站扩容后的最佳容配比,为未来光伏电站扩容设计提供指导方法。     

SolarPV 3D在光电建筑中光伏发电系统设计时的应用研究

自主开发了一款基于SketchUp软件的三维数字化设计插件SolarPV 3D,并对该插件的主要算法进行了介绍,算法包括光伏阵列自动化布置算法和逐时阴影遮挡计算方法,解决了光伏发电系统数字化设计过程中的关键技术难题,并提高了其设计效率。以河海大学常州校区英才楼的屋面光伏发电系统布置为例,结合无人机拍照三维成像技术及SolarPV 3D,完成了屋面光伏发电系统的布置及系统性能的仿真。SolarPV 3D使光伏发电系统设计的三维可视化程度得到明显提升,此外其还可提供光伏发电系统的性能数据,从而提高了光伏发电系统设计的经济性和实用性,具有重要的工程应用价值。     

Real-time simulation platform for photovoltaic system with a boost converter using MPPT algorithm in a DSP controller

Recently, real-time simulation of renewable energy sources are indispensible for evaluating the performance of the maximum power point tracking (MPPT) controller, especially in the photovoltaic (PV) system in order to reduce cost in the testing phase. Nowadays, real time PV simulators are obtained by using analog and/or digital components. In this paper, a real-time simulation of a PV system with a boost converter was proposed using only the digital signal processor (DSP) processor with two DC voltage sources to emulate the temperature and irradiation in the PV system. A MATLAB/Simulink environment was used to develop the real-time PV system with a boost converter into a C-program and build it into a DSP controller TMS320F28335. Besides, the performance of the real-time DSP-based PV was tested in different temperature and irradiation conditions to observe the P-V and V-I characteristics. Further, the performance of the PV with a boost converter was tested at different temperatures and irradiations using MPPT algorithms. This scheme was tested through simulation and the results were validated with that of standard conditions given in the PV data sheets. Implementation of this project helped to attract more researchers to study renewable energy applications without real sources. This might facilitate the study of PV systems in a real-time scenario and the evaluation of what should be expected for PV modules available in the market.     

System performance of a three-phase PV-grid-connected system installed in Thailand: Data monitored analysis

PV-grid-connected systems are worldwide installed because it allows consumer to reduce energy consumption from the electricity grid and to feed the surplus energy back into the grid. The system needs no battery so therefore the system price is very cheap comparing to other PV systems. PV-grid-connected systems are used in buildings that already hooked up to the electrical grid.Finding efficiency of the PV-grid-connected system can be done by using a standard instrument which needs to disconnect the PV arrays from the grid before measurement. The measurement is also difficult and we lose energy during the measurement.This paper will present the system performance of a PV-grid-connected system installed in Thailand by using a monitoring system. The monitored data are installed by acquisition software into a computer. Analysis of monitored data will be done to find out the system performance without disconnecting the PV arrays from the system. The monitored data include solar radiation, PV voltage, PV current, and PV power which has been recorded from a 5 kWp system installed of amorphous silicon PV at Rajamangala University of Technology Suvarnabhumi, Nonthaburi, Thailand. The system performance of the system by using the data monitored is compared to the standard instrument measurement. The paper will give all details about system components, monitoring system, and monitored data. The result of data analysis will be fully given.     

Polar coordinated fuzzy controller based real-time maximum-power point control of photovoltaic system

It is crucial to improve the photovoltaic (PV) system efficiency and to develop the reliability of PV generation control systems. There are two ways to increase the efficiency of PV power generation system. The first is to develop materials offering high conversion efficiency at low cost. The second is to operate PV systems optimally. However, the PV system can be optimally operated only at a specific output voltage and its output power fluctuates under intermittent weather conditions. Moreover, it is very difficult to test the performance of a maximum-power point tracking (MPPT) controller under the same weather condition during the development process and also the field testing is costly and time consuming. This paper presents a novel real-time simulation technique of PV generation system by using dSPACE real-time interface system. The proposed system includes Artificial Neural Network (ANN) and fuzzy logic controller scheme using polar information. This type of fuzzy logic rules is implemented for the first time to operate the PV module at optimum operating point. ANN is utilized to determine the optimum operating voltage for monocrystalline silicon, thin-film cadmium telluride and triple junction amorphous silicon solar cells. The verification of availability and stability of the proposed system through the real-time simulator shows that the proposed system can respond accurately for different scenarios and different solar cell technologies.     

Estimation of the energy of a PV generator using artificial neural network

The integration of grid-connected photovoltaic (GCPVS) systems into urban buildings is very popular in industrialized countries. Many countries enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy as a significant and sustainable renewable energy option. A previous method, based on artificial neural networks (ANNs), has been developed to electrical characterisation of PV modules. This method was able to generate V–I curves of si-crystalline PV modules for any irradiance and module cell temperature. The results showed that the proposed ANN introduced a good accurate prediction for si-crystalline PV modules performance when compared with the measured values. Now, this method, based on ANNs, is going to be applied to obtain a suitable value of the power provided by a photovoltaic installation. Specifically this method is going to be applied to obtain the power provided by a particular installation, the “Univer generator”, since modules used in these works were the same as the ones used in this photovoltaic generator.     

基于大数据分析的eHorus智慧云智能诊断系统在光伏电站巡检中的应用

随着全球光伏发电规模的日益扩大,光伏电站中光伏设备的状态监控、故障诊断与故障定位变得日益重要。基于此,介绍了一款可用于光伏电站中光伏设备的智能诊断系统——eHorus智慧云智能诊断系统,通过在云端构建光伏电站的光伏设备运行状态大数据中心,采集并存储包括光伏阵列在内的光伏电站全站光伏设备的实时运行状态数据,建立科学有效的大数据分析模型,实时对光伏电站全站光伏设备的运行情况进行线上智能巡检,以便及时发现低效设备或故障设备。对于诊断出异常的设备,智能诊断系统自动向光伏电站运维工程师推送报警信息并生成故障缺陷单,光伏电站运维工程师接到报警信息后快速到达故障设备现场,及时进行设备消缺,提高光伏电站全站光伏设备的运行水平。     

基于红外技术的变电站温度监控

针对变电站各发热点温度测量和监控问题,提出利用红外摄像机代替昂贵的红外热像仪对电力设备进行实时非精确的温度监控设计方案。该方案基于自源无线红外温度传感器,利用微型太阳能电池为测温和发射设备提供电源;发射端把测温传感器测得的温度量转化为红外信号并发射;接收端的红外监控摄像机对传感器扫描接收;监控中心对提取的红外图像处理、分析后,给出温度指示和异常报警信号。解决了变电站内高温高压强干扰问题。并开发了软件界面进行实时监控,做到各被测点的温度实时显示。通过实际检验,所设计的方案获得满意的效果。     

光伏并网电站数据采集监测系统

描述了计算机控制系统在光伏并网电站中的应用。介绍了数据采集监测系统的硬件结构以及软件的设计和实现。系统的硬件有并网逆变器、传感器、数据采集器等；系统的软件具有采集、处理、储存和查询功能。该数据采集监测系统为获取太阳能并网光伏电站的运行数据提供保证。     

Monitoring results of two examples of building integrated PV (BIPV) systems in the UK

This paper presents monitoring results of two examples of building integrated PV system investigated at the School of the Built Environment, University of Nottingham in the UK. One of the systems is installed on an educational building, and consists of a thin film PV façade appropriate for commercial or office suites. The other system is installed on a detached house, and uses crystalline PV roof slates, appropriate for domestic buildings. As the two buildings are significantly different in size, construction and occupancy, the design and selection of the PV system for each was also different. The monitoring investigation has assisted identification of shortfalls in performance and possible explanations have been suggested. The results presented in this paper provide information on the design process, and highlight similarities and differences in the design, installation, performance and economics of the two systems.     

BIPV: a real-time building performance study for a roof-integrated facility

Building integrated photovoltaic system (BIPV) is a photovoltaic (PV) integration that generates energy and serves as a building envelope. A building element (e.g. roof and wall) is based on its functional performance, which could include structure, durability, maintenance, weathering, thermal insulation, acoustics, and so on. The present paper discusses the suitability of PV as a building element in terms of thermal performance based on a case study of a 5.25?kW_p roof-integrated BIPV system in tropical regions. Performance of PV has been compared with conventional construction materials and various scenarios have been simulated to understand the impact on occupant comfort levels. In the current case study, PV as a roofing material has been shown to cause significant thermal discomfort to the occupants. The study has been based on real-time data monitoring supported by computer-based building simulation model.     

基于DSP与GPRS的电能质量监测系统

获取广泛的电能质量实时监测数据具有重要的意义,但高成本和数据传输的不便限制了电能质量实时监测的范围。为此提出以GPRS作为数据传输通道组成电能质量监测系统,并使用单片DSP作为核心开发出低成本的电能质量实时监测终端,详细介绍了如何充分利用DSP的片内外围设备以简化系统硬件设计,同时介绍了软件的设计和在算法上进行的优化。     

Predicting the energy production by solar photovoltaic systems in cold-climate regions

One challenge in designing a photovoltaic (PV) system is to predict its generation, given parameters such as location, meteorological conditions, and layout. A greater challenge is to predict the generation of such a system under snow-cover condition. Publicly available snowfall data provide records for horizontal surfaces. However, the effect of snow accumulated on a tilted PV module remains unknown. Hence, irradiance is insufficient for predicting the output of PV systems having any given layout configuration. The research in this paper aims to predict the daily generation of PV systems through the development of a predictive model flexible enough to accommodate different layout configurations based on long-term monitoring data collected from 85 sites. Snow coverage loss factors are derived empirically to enhance the performance of the model. A feed-forward artificial neural network model is developed and implemented with snow adjustments (snowfall data and snow coverage loss factors). Promising results are obtained and validated.     

A simple model of PV system performance and its use in fault detection

Results are presented from a monitoring study of the performance of a sample of UK domestic PV systems. Five-minute average climatic and performance data was recorded for 27 PV systems at two sites for up to 2 years of operation. On average, the annual energy losses due to faults were 3.6% (Site A, first year of operation), 6.6% (Site A, second year of operation) and 18.9% (Site B, first year of operation). Simple empirical models are constructed to describe the performance of the PV systems under ‘normal operation’ (when no faults occur). New analysis techniques are developed which estimate the energy losses of four different fault categories: sustained zero efficiency faults; brief zero efficiency faults; shading; and non-zero efficiency non-shading faults. The results demonstrate that faults have the potential to cause significant energy losses in domestic PV systems. The benefits of applying the data analysis techniques described in this work to PV system clusters and other urban micro-generation technologies are discussed.     

太阳能光热与光电/光热系统在中国不同建筑气候带下的性能研究

文章利用TRNSYS动态模拟软件研究了在我国不同建筑气候带条件下,不同类型的太阳能PV/T集热系统和普通太阳能PT集热系统的各项性能。其中,太阳能PV/T集热系统分为基于普通玻璃型太阳能PV/T集热系统和基于Low-e型太阳能PV/T集热系统。文章探究了基于普通玻璃型太阳能PV/T集热系统和基于Low-e型太阳能PV/T集热系统的电、热性能,分析了这两种太阳能PV/T集热器的光电转化效率,以及这两种太阳能PV/T集热系统和普通太阳能PT集热系统的光热转化效率、太阳能贡献率、一次能源节约率、供热节能率和环境效益等参数。分析结果表明:普通太阳能PT集热系统的吸热量、太阳能贡献率、供热节能率和CO₂减排量均高于太阳能PV/T集热系统;与基于普通玻璃型太阳能PV/T集热系统相比,基于Low-e型太阳能PV/T集热系统的发电量降低了3.77%,但热效率、太阳能贡献率、一次能源节约率、供热节能率和环境友好度均较高。     

Data acquisition system for photovoltaic water pumps

In Algeria, there are several photovoltaic water pumping system (PVWPS) which are situated in remote areas. Typical problems are detected as sizing of photovoltaic (PV) generator (over-sizing) and maintenance (underestimate) by many operators. Due to the high cost of setting up and maintaining a large number of data acquisition systems for the PVWPS, we have developed a real time expert system based on central microcomputer used as a micro-server, with a low cost. This paper presents a design of a universal data acquisition system for Algeria with available components and easily accessible with a central server. This data acquisition system analyses the performance of PVWPS. The systems hardware and software architectures and an application to test its performance are described.