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- 摘要
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- 实验方案
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Application of Titanium Dioxide Self-Cleaning Coatings on Photovoltaic Modules for Soiling Related Losses Reduction
摘要： Several studies have assessed the influence of soiling deposition on Photovoltaic (PV) modules front-cover with regards to performance losses over time. In fact, soiling phenomena in PV systems are ascribed as responsible for medium and long-term yield reduction up to 16% over the first-year of outdoor exposure. Provided that PV technology is a low yield energy production source, maintaining module initial power output declared values is of the outmost importance to ensure that the return time of investment matches project calculations. The scope of this work was a detailed investigation on self-cleaning coating application as a viable retrofit option on already installed modules, or on newly built PV systems, to avoid soiling build-up on front-covers and guarantee threshold performance level in time. The aim is to provide system designers with a consistent alternative to manual cleaning, without losing effectiveness in terms of yield maintenance. The use of self-cleaning coating instead of acting on panels on a regular basis is more convenient in terms of operation and cost. These issues were analyzed through a set of experiments performed both on commercial size modules and laboratory assembled samples. Results prove product compatibility with PV components and its effectiveness in preventing soiling and dust deposition. Outcomes are presented in terms of maximum power output (Pmax) variation according to measurements performed in Standard Test Conditions (STC) at different time steps. In addition, a parallel comparison with uncoated modules exposed to the same outdoor conditions is also proposed to allow for Pmax variation monitoring performed on a reference sample.
关键词： Titanium Dioxide,PV Maintenance,Soiling,Yield Losses,Self-Cleaning
更新于2025-09-23 15:23:52
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Directions of Research and Standardization in the Field of Outdoor Lighting
摘要： This paper aims to highlight current trends in research and standardization in light and lighting with focus on the outdoor lighting. Activities of the International Commission on Illumination (CIE) are briefly presented and detailed in selected topics picked up from the list of research priorities. The highlighted topics comprise adaptive lighting, tailored lighting, new lighting metrics, maintenance factor and obtrusive light issues in particular. Outlook for standardization items, priorities and strategy is outlined in the paper.
关键词： obtrusive light,smart lighting,research,outdoor lighting,maintenance factor,standardization,tailored lighting,light and lighting,adaptive lighting
更新于2025-09-23 15:21:21
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Evaluation of Selected Parameters of Non-Directional Household Lamps
摘要： Currently, in place of traditional incandescent lamps, the user of home lighting has the option of using halogen lamps. The lamps, compact fluorescent commercial offer is very wide and diverse, both as to the types of lamps and their prices. Usually, when buying a lamp, the user is guided by the price and parameters given on the packaging. Unfortunately, all parameters on the product packaging only constitute the manufacturer's declaration and do not always correspond to actual parameters. The basic requirements for non-directional lamps for home use are contained in the regulations of the Commission of the European Community. However, only the initial parameters are usually verified. Due to the long duration of measurements, operational parameters are not controlled each time. The article presents the results of tests and analysis of lumen maintenance factor of selected non-directional lamps for home use after a defined period of operation. The quality of the tested lamps was assessed.
关键词： selected non-directional lamps for home use,lamp lumen maintenance factor,initial parameter of lamp
更新于2025-09-23 15:21:21
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[IEEE 2019 12th International Conference on Measurement - Smolenice, Slovakia (2019.5.27-2019.5.29)] 2019 12th International Conference on Measurement - Resampling Method for Correction of Laser Tuning Fluctuations in OFDR Sensing System
摘要： When a new bug report is received, developers usually need to reproduce the bug and perform code reviews to find the cause, a process that can be tedious and time consuming. A tool for ranking all the source files with respect to how likely they are to contain the cause of the bug would enable developers to narrow down their search and improve productivity. This paper introduces an adaptive ranking approach that leverages project knowledge through functional decomposition of source code, API descriptions of library components, the bug-fixing history, the code change history, and the file dependency graph. Given a bug report, the ranking score of each source file is computed as a weighted combination of an array of features, where the weights are trained automatically on previously solved bug reports using a learning-to-rank technique. We evaluate the ranking system on six large scale open source Java projects, using the before-fix version of the project for every bug report. The experimental results show that the learning-to-rank approach outperforms three recent state-of-the-art methods. In particular, our method makes correct recommendations within the top 10 ranked source files for over 70 percent of the bug reports in the Eclipse Platform and Tomcat projects.
关键词： software maintenance,Bug reports,learning to rank
更新于2025-09-23 15:19:57
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Silicon solar cell-integrated stress and temperature sensors for photovoltaic modules
摘要： We propose silicon solar cell–integrated stress and temperature sensors as a new approach for the stress and temperature measurement in photovoltaic (PV) modules. The solar cell–integrated sensors enable a direct and continuous in situ measurement of mechanical stress and temperature of solar cells within PV modules. In this work, we present a proof of concept for stress and temperature sensors on a silicon solar cell wafer. Both sensors were tested in a conventional PV module setup. For the stress sensor, a sensitivity of (?47.41 ± 0.14)%/GPa has been reached, and for the temperature sensor, a sensitivity of (3.557 ± 0.008) × 10?3 K?1 has been reached. These sensors can already be used in research for increased measurement accuracy of the temperature and the mechanical stress in PV modules because of the implementation at the precise location of the solar cells within a laminate stack, for process evaluation, in-situ measurements in reliability tests, and the correlation with real exposure to climates.
关键词： in situ measurement,temperature measurement,PV module,temperature sensor,stress sensor,stress measurement,predictive maintenance
更新于2025-09-23 15:19:57
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Detection of cleaning interventions on photovoltaic modules with machine learning
摘要： Soiling losses are a major concern for remote power systems that rely on photovoltaic energy. Power loss analysis is efficient for the monitoring of large power plants and for developing an optimal cleaning schedule, but it is not adapted for remote monitoring of standalone photovoltaic systems that are used in rural and poor regions. Indeed, this technique relies on a costly and dirt sensitive irradiance sensor. This paper investigates the possibility of a low-cost monitoring of cleaning interventions on photovoltaic modules during daytime. We believe that it can be helpful to know whether the soiling is regularly removed or not, and to decide if it is necessary to carry out additional cleaning operations. The problem is formulated as a classification task to automatically identify the occurrence of a cleaning intervention using a time window of temperature, voltage and current measurements of a photovoltaic array. We investigate machine learning tools based on Logistic Regression, Support Vector Machines, Artificial Neural Networks and Random Forest to achieve such classification task. In addition, we study the influence of the temporal resolution of the signals and the feature extraction on the classification performance. The experiments are conducted on a real dataset and show promising results with classification accuracy of up to 95%. Based on the results, three implementation strategies addressing different practical needs are proposed. The results may be particularly useful for non-governmental organizations, governments and energy service companies to improve the maintenance level of their photovoltaic facilities.
关键词： Detection,Machine learning,Photovoltaics,Maintenance,Monitoring,Soiling
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Realization and Use of an IR Camera for Laboratory and On-field Electroluminescence Inspections of Silicon Photovoltaic Modules
摘要： Electroluminescence (EL) is a non-destructive technique, which detects the most common defects in Photovoltaic (PV) modules. High resolution EL images are generally obtained by infrared-sensitive cameras equipped with different semiconductors (indium gallium arsenide or silicon sensors). In the present work, a procedure is proposed to build and set up a high resolution EL camera for crystalline Si modules, equipped with a low-cost Si sensor. It can be used to perform EL test both indoor (lab) and outdoor (on-field). Experimental results from real PV plant highlight the combined use of I-V curves and EL images, for determining the amount of power losses and their causes.
关键词： electroluminescence,faults,maintenance,photovoltaic,current-voltage characteristic
更新于2025-09-19 17:13:59
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Actuation Framework for 5G-Enabled Network Slices with QoE/QoS Guarantees
摘要： Network slicing is identified as the enabling technology for efficient service delivery in future 5G networks. Moreover, a key aspect in 5G network slicing relates to the delivery and maintenance of QoS/QoE guarantees for the provisioned slices. This paper discusses an overall framework for coordinating and orchestrating the proper actuations to restore the provisioned end-to-end network slices requirements. In particular, a policy-based actuation system is adopted, where a policy framework applies policies tied to specific behaviours. Such policies, that may trigger configurations in the different segments of the infrastructure, are aimed to maintain or restore the QoS/QoE requirements of the slice.
关键词： network slicing,QoE actuation,optical networks,QoE monitoring,5G service maintenance
更新于2025-09-19 17:13:59
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A Simple Method to Test Microscope Objectives Using a Laser Pointer
摘要： The objective lens is regarded as the critical component for an optimal image in light microscopy. Not every damage to the lens surface may be easily visible during maintenance when the objective is removed and observed. The internal lens organization produces a magnified image of the outer lens surface. Shining the light of a laser pointer into the lens, and reproducing the image of the light exiting onto a flat surface, produces different images for intact and damaged objective lenses.
关键词： damaged lens,laser pointer,light microscope,maintenance,objective lens
更新于2025-09-19 17:13:59
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[IEEE 2019 International Conference on Power Electronics, Control and Automation (ICPECA) - New Delhi, India (2019.11.16-2019.11.17)] 2019 International Conference on Power Electronics, Control and Automation (ICPECA) - Hybrid algorithm for reactive power control in grid integrated Photovoltaic inverters
摘要： Prognostics and systems health management (PHM) is an enabling discipline that uses sensors to assess the health of systems, diagnoses anomalous behavior, and predicts the remaining useful performance over the life of the asset. The advent of the Internet of Things (IoT) enables PHM to be applied to all types of assets across all sectors, thereby creating a paradigm shift that is opening up significant new business opportunities. This paper introduces the concepts of PHM and discusses the opportunities provided by the IoT. Developments are illustrated with examples of innovations from manufacturing, consumer products, and infrastructure. From this review, a number of challenges that result from the rapid adoption of IoT-based PHM are identified. These include appropriate analytics, security, IoT platforms, sensor energy harvesting, IoT business models, and licensing approaches.
关键词： remaining useful life,reliability,Internet of things,prognostics and systems health management,maintenance
更新于2025-09-19 17:13:59