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Reduction of electrical power loss in a photovoltaic chain in conditions of partial shading
摘要： The paper presents the problem of losses of electrical power in photovoltaic chains during partial shading. Photovoltaic modules work best when the illumination is uniform over the entire light-sensitive surface. If a part of this surface is illuminated to a lesser extent, it often ceases to be a part of the electricity generator, but constitutes a resistance. To minimize this phenomenon, PV modules use bypass diodes, e.g. covering several dozen cells in a photovoltaic chain. In addition, parts of the photovoltaic module surface with lower exposure to sunlight may be additionally illuminated with a mirror positioned to reflect light. The analysis uses a photovoltaic chain model implemented in MATLAB/Simulink. The model describes the processes of electrical power generation in photovoltaic modules. The model corresponds to a laboratory photovoltaic system located in AGH in Cracow. In the presented model, each individual part may be illuminated with different light intensity. The light incident on the cells is a direct sunlight or light reflected from the mirror. The model allows for the analysis of the electrical power generated depending on the light profile of the photovoltaic system. The results of the model analysis may be applied in optimization of the PV modules’ configuration.
关键词： Partial shading,Modelling,Photovoltaic system,Sunlight reflection,Maximum power point tracking (MPPT)
更新于2025-09-19 17:13:59
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Distributed Energy Resources in Microgrids || Su-Do-Ku and symmetric matrix puzzles–based optimal connections of photovoltaic modules in partially shaded total cross-tied array configuration for efficient performance
摘要： The authors have endeavored to propose and analyze Su-Do-Ku-TCT and SM-TCT configurations with that of existed TCT configuration of PV array for performance improvisation under considered partial shading cases-I(cid:1)IV. The performance parameters such as power loss, PE, FF, and PR have been assessed and collated with classical TCT, Su-Do-Ku-TCT, and SM-TCT configurations. The results obtained from the SM-TCT configurations had fewer numbers of local maxima, and all the performance parameters were far better than TCT and Su-Do-Ku-TCT configurations. A simpler reconfiguration scheme can be employed to design arrays of any dimensions. Thus the proposed SM-TCT arrangement is helpful to design an efficient PV array for huge PV plants for maximum power generation.
关键词： photovoltaic modules,total cross-tied array configuration,symmetric matrix,partial shading,Su-Do-Ku
更新于2025-09-19 17:13:59
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Analysis on inverter selection for domestic rooftop solar photovoltaic system deployment
摘要： Partial shading is a common occurrence in residential and commercial photovoltaic (PV) installations. It causes mismatch losses, particularly in string and central inverter-based systems, leading to output power loss and in turn lower performance ratio under partial shading conditions. The choice of string configuration itself is critical in lowering mismatch losses and the levelized energy cost. While a range of commercial inverters with different string configurations and prices are available, many standard string topologies are not optimum for common settings under various shading scenarios. Therefore, in this article, we evaluate various string configurations attached to state-of-the-art commercial inverters widely used in the industry from both mismatch loss and cost perspective. We quantify the impact of various shading scenarios on multiple inverter configurations to ascertain the relative performance of PV systems under symmetrical shading as well as random shading in field settings. For multiple PV system configurations (on a single rooftop), the mismatch loss varied up to 2.3% and 6% under symmetrical shading and field settings, respectively. The levelized cost of electricity also varies from 0.062$/kWh to 0.041 $/kWh and is dependent on the type of inverter and string configurations.
关键词： grid tied system,mismatch losses,photovoltaic system,system configuration,partial shading
更新于2025-09-19 17:13:59
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An experimental study on photovoltaic module with optimum power point tracking method
摘要： With the latest development in the area of power electronics, the photovoltaic (PV) cell can be made to operate at the optimum peak point with increased system efficiency. To maximize the power on photovoltaic cells under various conditions, optimum power point tracking (OPPT) methods such as conventional and soft computing methods are used. But it is not providing accurate and efficient output due to its randomness, fixed step size, and poor convergence. In this paper, the adaptive differential evolution (ADE) algorithm is introduced in the solar module to obtain the maximum power, and it has the ability to reach the optimum peak with the shorter time period. An Apriori method is used in the proposed ADE algorithm, wherein mutation factor and crossover are used as control parameters to increase the speed. The ruggedness of the ADE algorithm is tested under different shading condition such as no shading, 30% shading, and 50% shading condition. Extensive simulation has been carried out using PV solar module, and the analysis has been tabulated and compared with the existing results. Various statistical metrics such as root mean square error, the relative error, tracking efficiency, standard deviation, and efficiency are used to evaluate the effectiveness and validate the feasibility of the proposed method. Further, hardware has been implemented and tested with this algorithm.
关键词： photovoltaic cell,differential evolution algorithm,shading condition,optimum power point tracking
更新于2025-09-19 17:13:59
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Attenuation correction for confocal laser scanning microscopy and its application in chromatography
摘要： The applicability of confocal laser scanning microscopy is limited e.g. by attenuation of the excitation and the fluorescence emission beam. As a prerequisite for further processing and analysis of the obtained microscopic images, a new method is presented for correcting this attenuation. The correction is based on beam modeling and on a differential form of the modified Beer-Lambert law. It turns out that the intensity decay can be modeled as a double convolution of the microscopic image with the intensities of the excitation semi-beam and the emission beam. Under weak assumptions made for the intensities of the fluorescent radiation and the detected signal, formulas for the attenuation correction and the attenuation simulation are derived. The method traces back to that one published by Roerdink which is modified concerning a more realistic beam modeling, avoiding the so-called weak attenuation expansion, and considering fluorescence excitation throughout the light cone of the excitation beam. The applicability of the method is demonstrated for synthetic examples as well as microscopic images of chromatographic beads. It is shown that the new method can be successfully applied for reconstructing the true fluorophore distribution in specimens even if the microscopic images are affected by strong attenuation.
关键词： shading correction,protein distribution,chromatographic purification,Fluorescence microscopy
更新于2025-09-19 17:13:59
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An effective maximum power point tracker for partially shaded solar photovoltaic systems
摘要： The photovoltaic (PV) systems should operate at a maximum power point (MPP) to extract the maximum possible output power with high tracking efficiency under various operating conditions This paper discusses a new maximum power point tracking (MPPT) technique to extract the peak power from the PV panel/array during partial shaded conditions (PSCs). The proposed algorithm is based on bio-inspired Whale Optimization (WO) with reinitialization process when the PV system is subjected to change in shading pattern, and the algorithm tries to locate the global peak (GP) with a high convergence rate and high tracking efficiency. The proposed algorithm eliminates the computational burden faced by the hybrid MPPT algorithms as discussed in various literature and reduces the power oscillation during the change in operating conditions. The proposed technique is modeled and simulated under different test conditions using MATLAB/Simulink software. The performance of the proposed technique is compared with conventional perturb and observation (PO), Grey Wolf Optimization (GWO) and hybrid GWO (HGWO) techniques in terms of tracking time and tracking efficiency and the simulation result proves that WO technique displays high tracking efficiency (>95%) and less convergence time (<0.15sec) under PSCs with less power oscillations. Moreover, the performance assessment is carried out in terms of mismatching loss, fill factor, and relative power loss/gain.
关键词： Partial shading,Performance assessment,Global peak,WO,Convergence time,MPPT
更新于2025-09-19 17:13:59
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A state-of-the-art review on conventional, soft computing, and hybrid techniques for shading mitigation in photovoltaic applications
摘要： This article intends to present a compendious review to extract maximum power in solar photovoltaic (PV) systems under varying environmental conditions and partial shading conditions by enumerating various circuit-based topologies and different state-of-the-art maximum power point techniques (MPPT). Partial shading reduces the overall efficiency of the PV system; therefore techniques that are dealing with partial shading play an important part in the power conditioning unit of all PV system connected to the stand-alone mode or grid mode. Various circuit-based topologies and various algorithms have been broadly discussed till date. As every algorithm is associated with its own merits and demerit, hence an extensive literature survey is required while planning for PV generating station under normal and partial shading condition. In this article, a comprehensive review of shading mitigation using different topologies has been done. The article on shading mitigation is broadly divided into two major groups. The first group includes all major circuit-based topologies and the second group includes MPPT based techniques, which has been further classified into modified conventional techniques, soft computing techniques, and hybrid techniques. This comprehensive review presents an assessment of all techniques according to parameters like converter used, tracking speed, complexity, efficiency, number of sensors under partial shading condition would certainly provide a single platform to carry forward their research in solar PV application.
关键词： global maximum power point,pulse width modulation,partial shading condition,photovoltaic generation System,hybrid optimization techniques,artificial intelligence
更新于2025-09-19 17:13:59
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Power recovery and equalization in partially shaded photovoltaic strings by an efficient switched capacitor converter
摘要： Partial shading is the major complication encountered by the Photovoltaic strings while delivering maximum power to the load. This scenario consequently diminishes the functionality of the modules causing mismatch, hotspot, power loss and multiple peaks formation in the characteristics curves of the strings. Also, formation of multiple peaks affects the performance of the maximum power point trackers due to false tracking resulting in severe power loss. In this paper, a switched-capacitor converter for power recovery and equalization in the strings during shading is proposed. The parallel-ladder architecture of the converter maintains voltage ratios by transferring power between the shaded and unshaded modules of the strings. The converter enables the string to generate maximum power by ensuring single peak in the characteristics curves during shading. The performance of the string with the proposed converter is compared to conventional strings using characteristics curves, and various performance parameters. The systems are tested in MATLAB/Simulink and experimental setup under various static and dynamic partial shading conditions. Also, the conduction losses encountered by the converter during power balancing in the strings are analysed and expressed mathematically. The results clearly indicate that the proposed converter can be easily implemented in the strings to recover the power losses and avoid multiple peaks formation in the characteristics curves during partial shading with efficiency greater than 99%.
关键词： Maximum power point,Photovoltaic (PV) strings,Partial shading,Differential power processing (DPP),Switched-capacitor (SC) converter
更新于2025-09-16 10:30:52
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Implementation of a modified circuit reconfiguration strategy in high concentration photovoltaic modules under partial shading conditions
摘要： A modified circuit reconfiguration (MCR) technique for high concentration photovoltaic (HCPV) modules under partial shading conditions (PSCs) is proposed. Although HCPV modules have high conversion efficiency, they are sensitive to changing environments, especially PSCs. In response, the MCR strategy exploits the reconfigurable wiring of HCPV modules to implement the dynamic circuit reconfiguration (DCR) technique. In doing so, the hardware switches and complex control algorithms of the conventional DCR are simplified to reduce cost. Moreover, an irradiation estimation method is proposed for string current equalization using existing switches and connections. Two circuit-model prototypes, one square and one rectangular, were simulated to evaluate the proposed MCR strategy. Evaluation results demonstrate that the average output-power and conversion-efficiency improvements of the square and rectangular modules were around 31.07% and 5.00%, and 32.79% and 5.23%, respectively, when compared with the original Series connection topology. In addition, after reconfiguration by MCR, the module’s GMPP power was improved and the number of LMPPs reduced, which simplified the P-V curves. Furthermore, reliability tests demonstrated that with a small reconfiguration processing time ratio (0.06–0.28%), the daily energy harvested from the rectangular module was improved around 15%. The proposed MCR strategy has the advantages of reducing the hardware/software costs and lowering circuit losses. Additionally, the MCR method can increase the output power and efficiency of an HCPV module with high dispersion ability. The proposed method and prototypes can also be extended to larger scale arrays or implemented with other PV systems.
关键词： High concentration photovoltaic systems (HCPV),Maximum power point tracking (MPPT),Dynamic circuit reconfiguration,Partial shading conditions (PSCs)
更新于2025-09-16 10:30:52
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Detailed modeling of large scale photovoltaic power plants under partial shading conditions
摘要： As the popularity of solar panels increases, significant research is being performed on maximizing the power extracted from photovoltaic systems. A phenomenon known as partial shading is a major source of power losses for photovoltaic plants. One way to reduce the effects of partial shading conditions is by using bypass–diodes. Typically any number of series and parallel–connected photovoltaic cells, known as photovoltaic cell arrays, are connected in anti–parallel with bypass–diodes. Due to this, it is advantageous to have an equivalent model for a photovoltaic cell array that is connected to bypass–diodes. In order to accurately develop this model, it is necessary to consider both series and parallel configurations of bypass–diodes, as well as the thermal behavior of bypass–diodes. The bypass–diode’s temperature model must be comprised of the constantly changing dissipated power, the effects of wind speed and the ambient temperature. This paper constructs an electro–thermal modular model for any size photovoltaic system and includes the effects of both the photovoltaic cells and bypass–diodes. A detailed analysis of the proposed model is performed and is then validated in both PSCAD/EMTDC and Matlab–Simscape. The proposed model is then further validated by the use of real measurements of ambient temperature, cell temperature, wind speed and then finally by a performance analysis of several maximum–power–point–tracking algorithms.
关键词： MPPT,Modeling,Bypass–diode,Photovoltaic,Partial shading
更新于2025-09-16 10:30:52