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GAN-Based Augmentation for Improving CNN Performance of Classification of Defective Photovoltaic Module Cells in Electroluminescence Images
摘要： Electroluminescence (EL) imaging is an effective way for the examining of photovoltaic (PV) modules. Compared with manual analysis, using Convolutional Neural Network (CNN) for classification is much more convenient but it requires a certain amount of annotated training samples which cannot be acquired handily. In this paper, we present a method for augmenting the existing dataset of EL images using Generative Adversarial Networks (GANS) and propose a model called AC-PG GAN aiming at this. Three chosen CNN models are used to examine the effectiveness of the proposed GAN model and have achieved an improvement of the classification accuracy with the augmented dataset after some adjustment and the maximum improvement is up to 14%.
关键词： Data Augmentation,Electroluminescence,Photovoltaic Modules,GAN,CNN
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 28th International Symposium on Industrial Electronics (ISIE) - Vancouver, BC, Canada (2019.6.12-2019.6.14)] 2019 IEEE 28th International Symposium on Industrial Electronics (ISIE) - A study on the lifetime estimation of photovoltaic modules under accelerated environmental conditions
摘要： Lifetime estimation is critical for predicting the revenue of the photovoltaic (PV) plant to be built. Therefore it must be done before huge investments will be made to build and operate a PV plant. Since the degradation rate of PV modules features as a random variable, statistical models are commonly used to estimate the lifetime of PV modules. However, most existing researches select the statistical model to describe the degradation rate of PV modules empirically, and lack of basis. In this paper we propose a practical procedure for selecting the statistical model which describes the degradation rate of PV modules best. Based on the selected model, the lifetime of PV modules is estimated. We use probability plots and hypothesis tests to validate the distributional assumptions. Then we use negative log-likelihood values to further determine the distribution that describes the lifetimes best. Three classical distributions, i.e., Weibull, lognormal and exponential distributions, are considered. The life distributions at different stress levels are assumed to come from the same parametric family. Based on the assumption, the parameters of the hypothesized distributions are estimated using maximum likelihood estimation methods. It is found that the PV lifetimes follow a parametric location-scale distribution family, and they follow the Weibull distribution best. The conclusion is realistic from a physical point of view.
关键词： accelerated tests,photovoltaic modules,statistical models,distribution determination,lifetime estimation
更新于2025-09-16 10:30:52
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Theoretical and Numerical Study of a Photovoltaic System with Active Fluid Cooling by a Fully-Coupled 3D Thermal and Electric Model
摘要： The paper deals with the three-dimensional theoretical and numerical investigation of the electrical performance of a Photovoltaic System (PV) with active fluid cooling (PVFC) in order to increase its efficiency in converting solar radiation into electricity. The paper represents a refinement of a previous study by the authors in which a one-dimensional theoretical model was presented to evaluate the best compromise, in terms of fluid flow rate, of net power gain in a cooled PV system. The PV system includes 20 modules cooled by a fluid circulating on the bottom, the piping network, and the circulating pump. The fully coupled thermal and electrical model was developed in a three-dimensional geometry and the results were discussed with respect to the one-dimensional approximation and to experimental tests. Numerical simulations show that a competitive mechanism between the power gain due to the cell temperature reduction and the power consumption of the pump exists, and that a best compromise, in terms of fluid flow rate, can be found. The optimum flow rate can be automatically calculated by using a semi-analytical approach in which irradiance and ambient temperature of the site are known and the piping network losses are fully characterized.
关键词： thermal–electrical model,solar energy,photovoltaic modules,active cooling,computational fluid dynamics (CFD)
更新于2025-09-16 10:30:52
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Analysis of degradation in 25-year-old field-aged crystalline silicon solar cells
摘要： Photovoltaic (PV) modules have been in use for more than 25 years. The gradual degradation of PV modules is determined by its components and the solar cells. We analyzed the long-term reliability of solar cells using a 25-year-old field-aged PV module. The power of a large size PV module was reduced by approximately 24.6% owing to the delamination of two specific solar cell portions. For a single cell module from a large size PV module, the decrease of short circuit current (Isc) was caused by the discoloration of the ethylene-vinyl acetate. The maximum power (Pmax) decreased by 11.5% compared with its initial value; however, this is not an effect of the degradation of the solar cell. Despite being manufactured in the 1980s, these solar cells did not fail and have little power loss and excellent durability after 25 years.
关键词： Degradation,Long-term durability,Solar cells,Reliability,Photovoltaic modules
更新于2025-09-16 10:30:52
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Challenges in the pre-normative characterization of bifacial photovoltaic modules
摘要： Bifacial photovoltaic (PV) technology is receiving growing interest on the market, with several companies commercializing bifacial modules alongside their conventional products, with various c-Si structures, such as PERC, PERT, HIT, IBC, etc. Current-voltage characterization of bifacial PV modules at Standard Test Conditions (STC) is challenging, as it requires an extension of the definition of STC that includes the spectral and total irradiance on the rear side of the module. Indoor characterization in principle allows the most accurate control of these quantities: the simplest procedure involves measurements of each side of the bifacial module at a time with a single light source, while carefully keeping the other side in the dark. This procedure requires attention to minimize unintended contributions to the module power from the non-illuminated side, which is associated to the reflected irradiance from surroundings, to the optical properties of the module, and to the geometrical disposition of the cells. This work revises the pre-normative activity that has led to the draft standard IEC 60904-1-2 (due for publication in 2018) and focuses on the new norm in what concerns indoor measurement with a single-source simulator. It illustrates the metrological challenges in the selection of the non-reflective material behind the non-illuminated side, and their impact to the electrical characterization of bifacial modules.
关键词： Electrical characterization,Standard Test Conditions,Solar simulators,Bifacial photovoltaic modules
更新于2025-09-12 10:27:22
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Novel thermodynamic efficiency indices for choosing an optimal location for large-scale photovoltaic power generation
摘要： Sustainable energy is a current key priority across the globe. Hence, renewable energy sources have been widely accepted as potential substitutes for fossil fuels in the existing energy infrastructures. A recent report showed that photovoltaic power generation constituted around 100 GW out of 2378 GW of the global renewable power capacity installed in 2018. Consequently, various researchers are investigating how the increasing utilisation of photovoltaics can be handled in order to reduce future environmental impacts; whilst leveraging their operational zero-emission. From a circular economic paradigm, recycling, reuse and reduction strategies are often adopted to improve the sustainability of systems. This study proposes novel thermodynamic ef?ciency indices as a resources reduction strategy. By selecting an optimal location for large-scale photovoltaic power generation (LSPPG), the same amount of resources (such as land space, materials, energy) will achieve higher utilisation ef?ciency. In this study, actual two-year solar radiation and temperature data were sourced from Nigerian Meteorological Agency, Abuja. A probability distribution modeling was used to generate statistical mean values for solar radiation and temperature based on the classical almost sure central limit theory. Then, Photovoltaic modeling and simulation code was used to simulate the power generation characteristics of the LSPPG. Comparative analyses of the results for a 5 MW (MW) LSPPG showed that statistical mean value of power generation, energy ef?ciency index and exergy ef?ciency index range from 0.76 to 0.99 MW, 1.315 to1.254 and 1.298 to1.237, respectively, across the locations studied. Overall, the thermodynamic ef?ciency indices can complement the current laboratory-based rating of the photovoltaic modules in order to establish the environmental, economic and policy rationales for sitting a LSPPG. This would ultimately improve the cradle-to-cradle management of LSPPG installations based on resources reduction strategy.
关键词： Solar energy,Thermodynamic ef?ciency indices,Nigeria,Photovoltaic modules,Modeling and simulation
更新于2025-09-12 10:27:22
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Research on China’s photovoltaic modules recycling models under extended producer responsibility
摘要： The global photovoltaic (PV) industry has been developing rapidly in recent years. We have to face the dilemma of waste PV modules at the end of their life. It is important for government to construct recycling system to collect waste PV modules in the future. This paper analyses the three recycling models under Extended Producer Responsibility (EPR) from the perspective of reverse supply chain. The Government Subsidy is taken into account in the recycling model as an incentive factor. This paper examines the level of the PV producer’s recycling responsibility which is expressed by the recycling proportion of producers. The results show that there are some general rules about recycling responsibility by comparing the results of di?erent models. What’s more, a coordinating way is designed in mixed recycling model within a certain recycling scale range in order to cut down the producer’s recycling cost. Our research shows that the coordinating way is a great method with practical value when it is di?cult for the government to implement a complete EPR system.
关键词： government subsidy,photovoltaic modules,Sustainability,remanufacture,extended producer responsibility,recycling
更新于2025-09-12 10:27:22
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Output power behavior of passivated emitter and rear cell photovoltaic modules during early installation stage: influence of light-induced degradation
摘要： The conversion efficiency of passivated emitter and rear cell (PERC) photovoltaic (PV) modules decreases via light-induced degradation (LID). In this study, two models of commercial PERC PV modules were employed. These modules were exposed outdoors until the accumulated solar irradiation reached 687 kW m?2 to investigate their power generation behavior during the early installation stage. The maximum output power (Pmax) finally decreased by 1.52% in one model and by 4.29% in the other model. Pmax of the latter model increased after LID owing to light-induced regeneration under open-circuit conditions. However, power generation in the array of the latter model connected to an electrical power grid was not changed after LID and no recovery was observed. It was found that the extent of degradation and the behavior differ depending on not only the difference in models but also the circuit conditions during exposure. ? 2019 The Japan Society of Applied Physics
关键词： early installation stage,power generation behavior,light-induced degradation,passivated emitter and rear cell,photovoltaic modules
更新于2025-09-11 14:15:04
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[IEEE 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Waikoloa Village, HI (2018.6.10-2018.6.15)] 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Artifact-Free Coring Procedures for Removing Samples from Photovoltaic Modules for Microscopic Analysis
摘要： An important step in producing more reliable and efficient photovoltaic modules is to establish a relationship between the microscopic properties of modules deployed in the field for many years and efficiency-related parameters. The first step in accomplishing this task is to be able to identify and remove small areas from these modules without causing any damage to these samples. In this work, we will describe two different procedures to core small areas of deployed and stressed solar panels produced with different materials (Si, CIGS, and CdTe), and we will prove that these processes did not damage the cored material. We will also show that the coring procedure changes for different types of photovoltaic modules.
关键词： photovoltaic modules,CdTe,CIGS,Si,Coring
更新于2025-09-11 14:15:04
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Photovoltaic Modules Monitoring Based on WSN With Improved Time Synchronization
摘要： In order to avoid clock skew in WSN (Wireless Sensor Networks) for large-scale photovoltaic modules monitoring, an improved time synchronization algorithm, TSP-GDM (Time Synchronization Protocol with Gaussian Delay Model) is proposed in this paper. Interdependence of local time stamps is established between network nodes according to a linear clock model. Local exchange and share of local time stamps in nodes are achieved by means of wireless transmission. An estimation method with the Gaussian Delay Model is designed to deal with the estimation problems of the node clock offset. The synchronization accuracy of the proposed method is veri?ed with the MATLAB simulation. It is found that TSP-GDM can be applied to synchronous topology of large-scale photovoltaic modules monitoring with a higher synchronization accuracy. Compared to RBS (Reference Broadcast Synchronization), TPSN (Timing-synchronization Protocol for Sensor Networks) and RTSP (Recursive Time-Sync Protocol for WSN), its synchronization accuracy in an inner layer has been increased by 22.57 μs, 15.7 μs and 4.26 μs respectively.
关键词： photovoltaic modules monitoring,time synchronization,Gaussian delay model,WSN
更新于2025-09-11 14:15:04