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[IEEE 2019 IEEE Energy Conversion Congress and Exposition (ECCE) - Baltimore, MD, USA (2019.9.29-2019.10.3)] 2019 IEEE Energy Conversion Congress and Exposition (ECCE) - Multilevel-Boost-Converter-Neutral-Point-Clamped-Inverter Photovoltaic System with MPPT Based on Fibonacci Search
摘要： This paper deals with a system composed by a photovoltaic array feeding a Neutral-Point-Clamped inverter by a dc-dc multilevel boost converter. The system is able to adequately operate under partial shading condition. A current control allows for the boost converter to operate at high frequency while the Maximum Power Point Tracking (MPPT) with the help of Fibonacci search. System operation is explained as well as its model, control and PWM strategy. Simulation and experimental results validate the theoretical studies.
关键词： Fibonacci search,Photovoltaic systems,maximum power point tracking,NPC inverter,partial shading,boost multilevel
更新于2025-09-12 10:27:22
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[IEEE 2019 4th World Conference on Complex Systems (WCCS) - Ouarzazate, Morocco (2019.4.22-2019.4.25)] 2019 4th World Conference on Complex Systems (WCCS) - A Comparative Study of Photovoltaic Array Configurations effect on the Output Power under Partial Shading Conditions
摘要： In the case of uniform conditions of temperature and radiation, the Power-Voltage characteristic of photovoltaic fields presents a Global Maximum Power Point (GMPP). In the case of non-uniform conditions, the Power-voltage characteristic has several Local Maximum Power Points (LMPPs), which can mislead conventional Maximum Power Point Tracking (MPPT) algorithms. The main objective of this study is to analyze the effect of partial shading on the output power by altering the adopted configuration of the photovoltaic PV array. The performance evaluation of each configuration is carried out by considering the Maximum Power Points (MPPs) generated, mismatching losses due to Partial Shading Conditions (PSCs), Open Circuit (OC) and Short Circuit (SC) conditions and the Fill Factor (FF). Photovoltaic field simulation is performed on Matlab / Simulink using a (5 * 3) configuration of photovoltaic panels.
关键词： Partial Shading Conditions,Maximum Power Point,Maximum Power Point Tracking,Photovoltaic Array Configuration
更新于2025-09-12 10:27:22
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[Institution of Engineering and Technology 5th IET International Conference on Clean Energy and Technology (CEAT2018) - Kuala Lumpur, Malaysia (5-6 Sept. 2018)] 5th IET International Conference on Clean Energy and Technology (CEAT2018) - The Impact of Energy Yield of a Photovoltaic System Under Partial Shading
摘要： Photovoltaic module is very susceptible to partial shading problem. In a photovoltaic power system, large number of photovoltaic modules are connected in series to provide required voltage and power. Due to large number of photovoltaic modules, the chances of every photovoltaic module to receive uniform solar irradiance become lower. Therefore, a photovoltaic system consists of large number of photovoltaic modules is even more susceptible to partial shading problem. This paper presents the investigation of the energy yield of a photovoltaic system under partial shading conditions. The investigation results shows that the energy yield of a photovoltaic system decreases as the shading heaviness increases. However, the effect is not constant. The effect is especially significant when the photovoltaic system is under lightly partial shaded conditions. In worst case, the energy yield of the photovoltaic system can drops up to 17.65 % as the shading heaviness increases by 20 %. Therefore, the partial shading need to be address in order to minimize the losses of the photovoltaic system under partial shading conditions.
关键词： Photovoltaic module,photovoltaic string,solar energy,partial shading
更新于2025-09-12 10:27:22
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Aspects of Aerial Laser Scanning when exploring unknown archaeological sites (Case study)
摘要： Obtaining geographical information on the Earth's surface can be very costly and tedious. For this reason, remote sensing methods are increasingly used for these purposes, which allow the acquisition of terrain information via devices most often placed on board of aircraft or satellites. Currently, aircraft carriers are not used only for the acquisition of image data through aerial photography, but they can also carry on board other devices to obtain data of a different nature. This device can be an aerial laser scanner—LiDAR (Light Detection and Ranging) that scans the terrain and objects on the surface with a high precision. It is an active method of remote Earth survey based on the measurement of the distance between the object under investigation and the aircraft itself. The result of this process is a set of precise georeferenced points, which is referred to as a point cloud. By using spatial analyzes, it is possible to use various post-processing methods and it has applications in areas such as forestry, archeology, hydrology, etc. This paper is devoted to the use of Aerial Laser Scanning (ALS) for the purpose of archaeological research on the case study of the Molpír hillfort which is situated at the eastern foot of the Little Carpathians. For collecting the data, the PA-34 Seneca aircraft carrier was used and equipped with the Trimble Harrier 68i advanced mapping system. In the past, several archaeological surveys have been conducted in this area by using terrestrial measurements, however ALS has provided a different view and has enabled identification of sites which have not been previously identified and examined.
关键词： airborne laser scanning,archaeology,feature detection,hill-shading,remote sensing
更新于2025-09-12 10:27:22
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Diffusion charge compensation strategy for power balancing in capacitor-less photovoltaic modules during partial shading
摘要： Photovoltaic arrays are highly susceptible to the partial shading that drastically reduces the power output by forming multiple peaks in the characteristics curves complicating the operation of maximum power point trackers (MPPTs). In this paper, a new diffusion charge compensation strategy for power enhancement in the arrays during partial shading has been proposed. The strategy eliminates the requirement of bypass diodes and passive energy storage components and uses the inherent diffusion capacitance of the module for power balancing during shading reducing cost and complexity. The strategy has been tested in MATLAB/Simulink environment and validated experimentally under various partial shading scenarios. The proposed strategy increases the power output and improves the tracking efficiency of the MPPTs by forming single maxima in the characteristics curves of the array during partial shading as compared to the conventional arrays with and without bypass diodes. Also, the proposed strategy excels in performance by increasing the power output of arrays during partial shading with a conversion efficiency of nearly 98%.
关键词： Photovoltaic,Power generation,Partial shading,Diffusion capacitance,Maximum power point tracker,Charge compensation
更新于2025-09-12 10:27:22
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[IEEE 2019 International Conference on Clean Electrical Power (ICCEP) - Otranto, Italy (2019.7.2-2019.7.4)] 2019 International Conference on Clean Electrical Power (ICCEP) - Comparative Analysis of Partial Shading Power Losses in Photovoltaic Topologies
摘要： The productivity of photovoltaic (PV) system is highly affected by the environmental conditions. The impact of partial shading conditions (PSC) on PV systems with various topologies is not necessarily the same. It is essential to demonstrate the role of PV topology in alleviating partial shading power losses. This paper presents a thorough comparative analysis of power losses incurred under partial shading conditions over different reported PV topologies. Power losses are analyzed for equally-rated PV systems subject to the same environmental conditions to highlight the privilege of some topologies over others. Power losses analysis is carried out based on the level of maximum power point tracking (MPPT).
关键词： partial shading conditions (PSC),power losses,photovoltaic (PV) system,maximum power point tracking (MPPT),PV topologies
更新于2025-09-12 10:27:22
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Organic Photovoltaics on Greenhouse Rooftops: Effects on Plant Growth
摘要： Greenhouse agriculture is a high-growth and high-volume market that rapidly expands worldwide to address the societal needs for food production. The increasing demand for energy to cover their requirements, coupled with the limited amount of available fossil fuels, has turned the agriculture community in the exploitation of renewable energy sources. Intensive research is currently focuses on the use of solar energy in agriculture constructions. Organic Photovoltaics (OPVs) are constantly gaining ground among other PV technologies due to their low weight, tunable optical transmittance, flexibility and high conformability. In this work, semi-transparent OPVs based on the blend of regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) were integrated on the rooftop of the 24 m2 experimental Mediterranean greenhouse covering the 22% of its total area in order to investigate its effect on the growth and behavior of cultivated pepper plants (Capsicum annuum). Under the shade of OPVs, the pepper plants produced 20.2% more fruit mass compared to the control ones. In addition, at the end of the growing season, the height of the shaded plants was 21.8% larger than the remaining plants.
关键词： shading effect,solar energy,greenhouse,semi-transparent OPVs,printed photovoltaics
更新于2025-09-12 10:27:22
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Hardware Approach to Mitigate the Effects of Module Mismatch in a Grid-connected Photovoltaic System: A Review
摘要： This study reviews the hardware approach to mitigate the e?ects of module mismatch in a grid-connected photovoltaic (PV) system. Unlike software solutions, i.e. the maximum power tracking algorithm, hardware techniques are well suited to enhance energy yield because of their inherent ability to extract energy from the mismatched module. Despite the extra cost of the additional circuitry, hardware techniques have recently gained popularity because of their long-term ?nancial bene?ts. Notwithstanding the growing interest in this topic, review papers that provide updates on the technological developments of the three main hardware solutions, namely micro inverter, DC power optimizer, and energy recovery circuits, are lacking. This is in contrast to software solutions, which have had a considerable number of reputable reviews. Thus, a comprehensive review paper is appropriate at this juncture to provide up-to-date information on the latest topologies, highlight their merits/drawbacks, and evaluate their comparative performance.
关键词： micro inverter,hardware solutions,maximum power point tracker,photovoltaic,DC power optimizer,energy recovery,partial shading,module mismatch
更新于2025-09-12 10:27:22
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Recent Developments in Photovoltaic Materials and Devices || A Quick Maximum Power Point Tracking Method Using an Embedded Learning Algorithm for Photovoltaics on Roads
摘要： This chapter presents a new approach to realize quick maximum power point tracking (MPPT) for photovoltaics (PVs) bedded on roads. The MPPT device for the road photovoltaics needs to support quick response to the shadow flickers caused by moving objects. Our proposed MPPT device is a microconverter connected to a short PV string. For real-world usage, several sets of PV string connected to the proposed microconverter will be connected in parallel. Each converter uses an embedded learning algorithm inspired by the insect brain to learn the MPPs of a single PV string. Therefore, the MPPT device tracks MPP via the perturbation and observation method in normal circumstances and the learning machine learns the relationships between the acquired MPP and the temperature and magnitude of the Sun irradiation. Consequently, if the magnitude of the Sun beam incident on the PV panel changes quickly, the learning machine yields the predicted MPP to control a chopper circuit. The simulation results suggested that the proposed MPPT method can realize quick MPPT.
关键词： microconverter,maximum power point tracking (MPPT),incremental learning,modal regression on a fixed memory budget,photovoltaics bedded on road,insect brain,shadow flicker,embedded learning algorithm,partial shading
更新于2025-09-12 10:27:22
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Experimental Investigation of the Shading and Mismatch Effects on the Performance of Bifacial Photovoltaic Modules
摘要： Bifacial photovoltaic (PV) modules are drawing increasing attention because of their potential in gaining extra energy from the rear-side irradiance. However, the rear-side irradiance can cause the performance of bifacial PV modules to be different from the performance of monofacial PV modules under shading and mismatch conditions. For bifacial modules, two factors can lead to the irradiance mismatch: the front-side partial shading and the rear-side irradiance inhomogeneity. This experimental work aimed to study the impact of these two factors on the performance of bifacial PV modules. The effect of front-side partial shading was investigated by comparing the electrical and thermal behavior of bifacial and monofacial PV modules under different shading conditions. The influence of rear-side irradiance inhomogeneity was investigated by analyzing the operating voltages of the solar cells in a bifacial PV module under certain typical installation conditions. To further explain the origin of the mismatch effect, a diode model circuit was applied in the analysis. The results indicate that even when the bypass diode of the bifacial PV module was activated, the shaded bifacial cells still received extra irradiance and produced higher heat. Thus, in most cases, the mismatch caused by the front-side partial shading may result in a greater reliability risk for the bifacial PV modules compared with the monofacial PV modules. For the mismatch effect of bifacial PV modules caused by the rear-side irradiance inhomogeneity, the significant reliability issues (such as reverse bias of solar cells and hotspot problems) would rarely happen, mainly because of the limited inhomogeneity of the equivalent irradiance and logarithmical increasing relationship between the voltage deviation and irradiance deviation of each solar cell.
关键词： shading effect,mismatch,thermal characteristic,Bifacial,outdoor test,photovoltaic (PV) module
更新于2025-09-12 10:27:22