Study on Image Recognition Algorithm for Residual Snow and Ice on Photovoltaic Modules

The accumulation of snow and ice on PV modules can have a detrimental impact on power generation,leading to reduced efficiency for prolonged periods.Thus,it becomes imperative to develop an intelligent system capable of accurately assessing the extent of snow and ice coverage on PV modules.To address this issue,the article proposes an innovative ice and snow recognition algorithm that effectively segments the ice and snow areas within the collected images.Furthermore,the algorithm incorporates an analysis of the morphological characteristics of ice and snow coverage on PV modules,allowing for the establishment of a residual ice and snow recognition process.This process utilizes both the external ellipse method and the pixel statistical method to refine the identification process.The effectiveness of the proposed algorithm is validated through extensive testing with isolated and continuous snow area pictures.The results demonstrate the algorithm’s accuracy and reliability in identifying and quantifying residual snow and ice on PV modules.In conclusion,this research presents a valuable method for accurately detecting and quantifying snow and ice coverage on PV modules.This breakthrough is of utmost significance for PV power plants,as it enables predictions of power generation efficiency and facilitates efficient PV maintenance during the challenging winter conditions characterized by snow and ice.By proactively managing snow and ice coverage,PV power plants can optimize energy production and minimize downtime,ensuring a sustainable and reliable renewable energy supply.

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.

Photovoltaic Cells and Modules towards Terawatt Era

Progresses in photovoltaic technologies over the past years are evident from the lower costs, the rising efficiency, to the great improvements in system reliability and yield. Cumulative installed power yearly growths were on an average more than 40% in the period from 2007 to 2016 and in 2016, the global cumulative photovoltaic power installed has reached 320 GWp. The level 0.5 TWp could be reached before 2020. The production processes in the solar industry still have great potential for optimization both wafer based and thin film technologies. Trends following from the present technology levels are discussed, also taking into account other parts of photovoltaic systems that influence the cost of electrical energy produced. Present developments in the three generations of photovoltaic modules are discussed along with the criteria for the selection of appropriate photovoltaic module manufacturing technologies. The wafer based crystalline silicon(csilicon) technologies have the role of workhorse of present photovoltaic power generation, representing more than 90% of total module production. Further technology improvements have to be implemented without significantly increasing costs per unit, despite the necessarily more complex manufacturing processes involved. The tandem of c-silicon and thin film cells is very promising. Durability may be a limiting factor of this technology due to the dependence of the produced electricity cost on the module service time.

A Study of the Temperature Influence on Different Parameters of Mono-Crystalline Silicon Photovoltaic Module

In this article, the effect of temperature on the photovoltaic parameters of mono-crystalline silicon Photovoltaic Panel is undertaken, using the Matlab environment with varying module temperature in the range 25°C - 60°C at constant solar irradiations 200 - 500 W/m2. The results show that the temperature has a significant impact on the various parameters of the photovoltaic panel and it controls the quality and performance of the solar panel. The photovoltaic parameters are the current of short circuit Isc, the open circuit voltage Vco, the form factor FF, the maximum power Pmax as well as efficiency. The relative change of these photovoltaic parameters with temperature is also evaluated in this article. A DS-100M solar panel has been used as reference model. The results show also that the open circuit voltage, maximum power, fill factor and efficiency decrease with temperature, but the short circuit current increases with temperature. The results are in good agreement with the available literature.

Modeling of a Photovoltaic Module Considering the Solar Energy Available from Horizontal Surfaces over Kuwait Area

The paper identifies and analyzes the geographical and temporal variability of solar energy in Kuwait. The fundamental solar trigonometric model has been modified to estimate daily and hourly solar radiation on horizontal surfaces on the basis of the more readily available meteorological data. The results demonstrate that Kuwait has an abundance of solar energy capability. An overview of the production and consumption of electrical energy, installed capacity, and peak loads in Kuwait is also presented. Finally, it is shown how the power produced from the photovoitaic （PV） cells depends on the solar radiation. The proposed PV module is made up of a combination of series and parallel cells to increase power, while the IoV characteristic and output power of the module each month may be obtained from the model.

Modelling Study of Magnetic Field Effect on the Performance of a Silicon Photovoltaic Module

Solar Photovoltaic is a very promising solution that can greatly contribute in solving the increasing global energy demand. In both rural and urban areas, photovoltaic modules are in some instances installed close to telecommunication antennas or voltage transformers which generate important magnetic fields in their vicinity. The question is whether or not these magnetic fields affect the performances of the photovoltaic installations. This article presents a modelling study of external magnetic field effect on the electrical parameters of a photovoltaic module. The photocurrent, the photovoltage, the electric power, the series and the shunt resistances of the photovoltaic module, made up of ideal cells, are deduced from those of a silicon solar cell. Then, the I-V and P-V curves are plotted and the theoretical values of the electrical parameters of the photovoltaic module are deduced. The series and shunt resistances of the photovoltaic module are calculated using well known equations and the previous electrical parameters. The results show the negative effect of magnetic field on the performance of a solar photovoltaic module.

Modeling of the Photovoltaic Module Operating Temperature for Various Weather Conditions in the Tropical Region

The operating temperature is a critical factor affecting the performances of photovoltaic(PV)modules.In this work,relevant models are proposed for the prediction of this operating temperature using data(ambient temperature and solar irradiance)based on real measurements conducted in the tropical region.For each weather condition(categorized according to irradiance and temperature levels),the temperatures of the PV modules obtained using the proposed approach is compared with the corresponding experimentally measured value.The results show that the proposed models have a smaller Root Mean Squared Error than other models developed in the literature for all weather conditions,which confirms the reliability of the proposed framework.

Performance on Power,Hot and Cold Water Generation of a Hybrid Photovoltaic Thermal Module

This paper proposed a new function of photovoltaic thermal(PVT)module to produce nocturnal cool water not just only generating electrical power and hot water during daytime.Experimental tests were carried out under Chiang Mai tropical climate with a 200 Wp monocrystalline PVT module having dimensions of 1.601 m×0.828 m connected with two water tanks each of 60 L taken for hot and cool water storages.The module was facing south with 18o inclination.The electrical load was a 200 W halogen lamp.From experiments,by taking the module as a nocturnal radiative cooling surface,the cool water temperature in the cool storage tank could be reduced 2℃–3℃each night and the temperature could be reduced from 31.5℃to 22.1℃within 4 consecutive days.The cool water at approximately 23℃was also used to cool down the PVT module from noon when the PVT module temperature was rather high,and then the module temperature immediately dropped around 5℃and approximately 10%increase of electrical power could be achieved.A set of mathematical models was also developed to predict the PVT module temperature and the hot water temperature including the cool water temperature in the storage tanks during daytime and nighttime.The simulated results agreed well with the experimental data.

Mechanical Integrity and Failure Analysis of Photovoltaic Modules under Simulated Snow Loads Using Pneumatic Airbag Setup

Photovoltaic (PV) modules have emerged as an ideal technology of choice for harvesting vastly available renewable energy resources. However, the efficiency of PV modules remains significantly lower than that of other renewable energy sources such as wind and hydro. One of the critical elements affecting a photovoltaic module’s efficiency is the variety of external climatic conditions under which it is installed. In this work, the effect of simulated snow loads was evaluated on the performance of PV modules with different types of cells and numbers of busbars. According to ASTM-1830 and IEC-1215 standards, a load of 5400 Pa was applied to the surface of PV modules for 3 hours. An indigenously developed pneumatic airbag test setup was used for the uniform application of this load throughout the test, which was validated by load cell and pressure gauge. Electroluminescence (EL) imaging and solar flash tests were performed before and after the application of load to characterize the performance and effect of load on PV modules. Based on these tests, the maximum power output, efficiency, fill factor and series resistance were determined. The results show that polycrystalline modules are the most likely to withstand the snow loads as compared to monocrystalline PV modules. A maximum drop of 32.13% in the power output and a 17.6% increase in series resistance were observed in the modules having more cracks. These findings demonstrated the efficacy of the newly established test setup and the potential of snow loads for reducing the overall performance of PV module.

Design of Dismantling and Recycling Equipment for Junction Boxes of Waste Crystal Silicon Photovoltaic Modules

The dismantling and recycling of junction boxes,which is an important part of the photovoltaic module recycling process,was tested and designed scientifically.The equipment framework was built by three-dimensional simulation,and then the design of dismantling and recycling equipment for junction boxes of waste crystal silicon photovoltaic modules was completed through the experimental test and data analysis.The experimental results show that the initial idea of the dismantling scheme is correct,and the structure is feasible.However,some problems were not considered.This study provides reliable data support for the subsequent equipment development and ensures the smooth development of the subsequent design work.

Performance Comparison of Photovoltaic Modules under Low Sunlight

The DC energy produced by photovoltaic （PV） modules can change depending on the cell type, module components and module technology. The cell efficiency, sensitivity of the cell to light, recombination losses and how much the light reflects within the cell will affect the amount of produced energy. In addition, the energy produced will change depending on what wavelength light and how much can be transmitted through the front glass and encapsulant and how much light is reflected from back encapsulant and back cover. The front glass transmissivity, patterned surface and existence of ARC （anti-reflective coating） are all very important. In this research project, 14 modules were tested： 4 modules Glass/Glass （Perc Mono Cell）, 4 modules Glass/Ceramic （Perc Mono Cell）, 2 modules Glass/Glass bifacial （HIT Cell）, 1 module Standard （Framed, Mono-n type Cell）, 2 modules Standard （Framed, Poly Cell）, 1 module Standard （Framed, Perc Mono Cell）. This paper compares the normalized Wh/Wp ratios of the different modules under low irradiance （morning and afternoon light） and analyzes and investigates the obtained results as per the cell type used, module components and module technology.

Characterization of Simulator and Relative Spectral Responsivity Measurements of Photovoltaic Modules with Band Pass Filter Technique

One of the most important parameter used for the evaluation of the energy rating of PV modules is, their spectral responsivities which are the measure of electrical performance parameters per incident solar radiation. In this work, spectral responsivity measurements of a mono-crystalline, a poly-crystalline, a CIGS thin film and a bifacial module were measured using xenon-based flash type solar simulator system and a set of band pass filters. For the comprehensive characterization of parameters that may influence the spectral responsivity measurements, initially the simulator system was characterized both optically and thermally according to the IEC60904-9 and IEC60891 standard requirements. The optical characterizations in terms of spectral match, spatial non-uniformity and temporal instability indicate that the measured results (~3.0%, ~0.30% and ~0.20%) according to the IEC 60904-9 standard’s classification requirements correspond to A+A+A+ classes. Moreover, thermal characterizations in terms of the temperature uniformity show that over the 2 × 2 m area temperature uniformity of simulator system’s light distribution (1ºC) is almost two times better than the IEC 60891 standard requirements (±2ºC). Next, PV modules were electrically stabilized according to the IEC 61215-2 standard requirement’s (stability test) to reduce the fluctuations in their electrical performance parameters. Then, using the band pass filters, temperature controlled xenon-based solar simulator system and a reference PV module of the spectral responsivity of PV modules were measured from 400 nm to 1100 nm with 50 nm steps with relative uncertainty of 10-3 level.

A review on the cooling of energy conversion and storage systems using thermoelectric modules

Exploitation of sustainable energy sources requires the use of unique conversion and storage systems,such as solar panels,batteries,fuel cells,and electronic equipment.Thermal load management of these energy conversion and storage systems is one of their challenges and concerns.In this article,the thermal management of these systems using thermoelectric modules is reviewed.The results show that by choosing the right option to remove heat from the hot side of the thermoelectric modules,it will be a suitable local cooling,and the thermoelectric modules increase the power and lifespan of the system by reducing the spot temperature.Thermoelectric modules were effective in reducing panel temperature.They increase the time to reach a temperature above 50℃ in batteries by 3 to 4 times.Also,in their integration with fuel cells,they increase the power density of the fuel cell.

基于串联型DC module的光伏发电系统研究

提出了一种基于串联型直流功率单元(DC module)电路的光伏发电系统,讨论了采用单端反激变换器实现的DC module电路。由于反激变换器用于升压变换时变压器原边电流较大,当并联使用时效率较低,为了减小DC module电路升压压力,提高每组变换器能量传输效率,采用串联形式的DC module电路,且每组DC module电路使用独立的最大功率追踪算法,由此组成的光伏发电系统提高了DC module电路的升压效率,且可以实现每块光伏电池板的最大功率点跟踪,解决了不同光照(阴影)、不同规格以及不同朝向等因素引起的失配问题。实验结果表明,当一路或多路电路中的电池板受到阴影影响时,各路电池板在控制器的作用下仍然工作在各自的最大功率点处。

Remaining Life Prediction Method for Photovoltaic Modules Based on Two-Stage Wiener Process

Photovoltaic (PV) modules, as essential components of solar power generation systems, significantly influence unitpower generation costs.The service life of these modules directly affects these costs. Over time, the performanceof PV modules gradually declines due to internal degradation and external environmental factors.This cumulativedegradation impacts the overall reliability of photovoltaic power generation. This study addresses the complexdegradation process of PV modules by developing a two-stage Wiener process model. This approach accountsfor the distinct phases of degradation resulting from module aging and environmental influences. A powerdegradation model based on the two-stage Wiener process is constructed to describe individual differences inmodule degradation processes. To estimate the model parameters, a combination of the Expectation-Maximization(EM) algorithm and the Bayesian method is employed. Furthermore, the Schwarz Information Criterion (SIC) isutilized to identify critical change points in PV module degradation trajectories. To validate the universality andeffectiveness of the proposed method, a comparative analysis is conducted against other established life predictiontechniques for PV modules.

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。

Improved Voltage Control Strategy for Photovoltaic Grid-Connected System Based on DoubleLayer Coordination Control

An improved automatic voltage coordination control strategy （AVCCS） based on ;automatic voltage control （AVC） and battery energy storage control （BESC） is proposed for photovoltaic grid-connected system （PVGS） to mitigate the voltage fluctuations caused by environmental disturbances. Only AVC is used when small environ- mental disturbances happen, while BESC is incorporated with AVC to restrain the voltage fluctuations when large disturbances happen. An adjustable parameter determining the allowed amplitudes of voltage fluctuations is introduced to realize the above switching process. A benchmark low voltage distribution system including ]？VGS is established by using the commercial software Dig SILENT. Simulation results show that the voltage under AVCCS satisfies the IEEE Standard 1547, and the installed battery capacity is also reduced. Meanwhile, the battery＇s service life is ex- tended by avoiding frequent charges/discharges in the control process.

Moisture Absorption and Desorption in an Ionomer-Based Encapsulant:A Type of Self-Breathing Encapsulant for CIGS Thin-Film PV Modules

As an alternative to conventional encapsulation concepts for a double glass photovoltaic(PV)module,we introduce an innovative ionomer-based multi-layer encapsulant,by which the application of additional edge sealing to prevent moisture penetration is not required.The spontaneous moisture absorption and desorption of this encapsulant and its raw materials,poly(ethylene-co-acrylic acid)and an ionomer,are analyzed under different climatic conditions in this work.The relative air humidity is thermodynamically the driving force for these inverse processes and determines the corresponding equilibrium moisture content(EMC).Higher air humidity results in a larger EMC.The homogenization of the absorbed water molecules is a diffusion-controlled process,in which temperature plays a dominant role.Nevertheless,the diffusion coefficient at a higher temperature is still relatively low.Hence,under normal climatic conditions for the application of PV modules,we believe that the investigated ionomer-based encapsulant can“breathe”the humidity:During the day,when there is higher relative humidity,it“inhales”(absorbs)moisture and restrains it within the outer edge of the module;then at night,when there is a lower relative humidity,it“exhales”(desorbs)the moisture.In this way,the encapsulant protects the cell from moisture ingress.

Ghost-Retina Net:Fast Shadow Detection Method for Photovoltaic Panels Based on Improved Retina Net

Based on the artificial intelligence algorithm of RetinaNet,we propose the Ghost-RetinaNet in this paper,a fast shadow detection method for photovoltaic panels,to solve the problems of extreme target density,large overlap,high cost and poor real-time performance in photovoltaic panel shadow detection.Firstly,the Ghost CSP module based on Cross Stage Partial(CSP)is adopted in feature extraction network to improve the accuracy and detection speed.Based on extracted features,recursive feature fusion structure ismentioned to enhance the feature information of all objects.We introduce the SiLU activation function and CIoU Loss to increase the learning and generalization ability of the network and improve the positioning accuracy of the bounding box regression,respectively.Finally,in order to achieve fast detection,the Ghost strategy is chosen to lighten the size of the algorithm.The results of the experiment show that the average detection accuracy(mAP)of the algorithm can reach up to 97.17%,the model size is only 8.75 MB and the detection speed is highly up to 50.8 Frame per second(FPS),which can meet the requirements of real-time detection speed and accuracy of photovoltaic panels in the practical environment.The realization of the algorithm also provides new research methods and ideas for fault detection in the photovoltaic power generation system.

Photovoltaic Models Parameters Estimation Based on Weighted Mean of Vectors

Renewable energy sources are gaining popularity,particularly photovoltaic energy as a clean energy source.This is evident in the advancement of scientific research aimed at improving solar cell performance.Due to the non-linear nature of the photovoltaic cell,modeling solar cells and extracting their parameters is one of the most important challenges in this discipline.As a result,the use of optimization algorithms to solve this problem is expanding and evolving at a rapid rate.In this paper,a weIghted meaN oF vectOrs algorithm(INFO)that calculates the weighted mean for a set of vectors in the search space has been applied to estimate the parameters of solar cells in an efficient and precise way.In each generation,the INFO utilizes three operations to update the vectors’locations:updating rules,vector merging,and local search.The INFO is applied to estimate the parameters of static models such as single and double diodes,as well as dynamic models such as integral and fractional models.The outcomes of all applications are examined and compared to several recent algorithms.As well as the results are evaluated through statistical analysis.The results analyzed supported the proposed algorithm’s efficiency,accuracy,and durability when compared to recent optimization algorithms.