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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
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Study of Power Optimizers for grid-connected photovoltaic systems
摘要： The use of Photovoltaic (PV) energy is increasing and the high penetration of PV in the power grid creates several challenges. The main challenge consists in reducing power losses in conversion. The main losses are those caused by total and partial shading, mismatch losses, ohmic loss, and temperature. In this occasion, Power Optimizer for Photovoltaic Systems (POPS) have recently appeared, which aim at increasing the energy conversion of the PV system. Thus, this work presents the POPS and performs simulations with PV*SOL software verifying the gain provided under different conditions. As a result, in the best case, Optimization Performance (Op) reached 10.84% (SolarEdge) in Sete Lagoas-MG and 7.17% (Tigo) in Curitiba-PR. Therefore, POPS may be a solution for improving energy conversion of the PV system, mainly due to the ongoing reduction in the cost of power electronics.
关键词： POPS,photovoltaic systems,losses,Power optimizer
更新于2025-09-11 14:15:04
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An Improved Particle Swarm Optimization Algorithm Suitable for Photovoltaic Power Tracking Under Partial Shading Conditions
摘要： The partial shading of a photovoltaic array repeatedly occurs in the natural environment, which can cause a failure of a conventional maximum power point tracking (MPPT) algorithm. In this paper, the convergence conditions of the standard particle swarm optimization (PSO) algorithm are deduced by the functional analysis, and then the influence of the random variables and inertia factor of the algorithm on the trajectory in the particle swarm optimization is analyzed. Based on the analysis results, an improved particle swarm optimization (IPSO) algorithm, which adopts both global and local modes to locate the maximum power point, is proposed. Compared to the standard PSO algorithm, in the improved PSO algorithm, many random and interfered variables are removed, and the structure is optimized significantly. The proposed algorithm is first simulated in MATLAB to ensure its capability. The feasibility of the approach is validated through physical implementation and experimentation. Results demonstrate that the proposed algorithm has the capability to track the global maximum power point within 3.3 s with an accuracy of 99%. Compared with five recently developed Global MPPT algorithms, the proposed IPSO algorithm achieved better performance in the maximum power tracking in the partial shading conditions.
关键词： partial shade,particle swarm optimization,Maximum power point tracking,photovoltaic array
更新于2025-09-11 14:15:04
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Improved Restricted Control Set Model Predictive Control (iRCS-MPC) Based Maximum Power Point Tracking of Photovoltaic Module
摘要： This paper presents a robust two stage maximum power point tracking (MPPT) system of the photovoltaic (PV) module using an improved restricted control set model predictive control (iRCS-MPC) technique. The suggested work is improved in two aspects; a revision in conventional P&O algorithm is made by employing three distinct step sizes for different conditions, and an improvement in conventional MPC algorithm. The improved MPC algorithm is based on the single step prediction horizon that provides less computational load and swift tracking of maximum power point (MPP) by applying the control pulses directly to the converter switch. The computer aided experimental results for various environmental scenarios revealed that compared with the conventional method (conventional P&O + MPC), for the PV power and inductor current, the undershoot and overshoot is decreased to 68% and 35% respectively under stiff environmental conditions. In addition, the settling time needed to reach a stable state is significantly reduced in the proposed system. The viability of the solution suggested is verified in MATLAB/Simulink and by hardware experimentation.
关键词： maximum power point tracking (MPPT),photovoltaic systems,MPC,Boost converter,dc-dc power conversion,model predictive control (RCS-MPC)
更新于2025-09-11 14:15:04
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Coupled electrical-thermal modelling of photovoltaic modules under dynamic conditions
摘要： This paper presents a coupled electrical-thermal model for solar photovoltaic (PV) modules, under an unsteady state and various conditions, including ambient temperature, solar radiation and wind velocity. Validation shows that the electrical and thermal models present high agreement with the experimental data. The developed model after validation is then applied to investigate the distribution of thermal resistance, the in?uence of environmental conditions and cooling methods. Results show that the radiative and convective thermal resistances play a signi?cant role in PV electrical-thermal performance, while conductive thermal resistance can be neglected for simpli?cation in some cases. The results also demonstrate the effects of weather conditions including solar radiation, ambient temperature and wind velocity on PV performance vary and they need to be selected carefully during parameters design. Moreover, a dynamic estimation of different seasons and a long-term evaluation of an entire year for a speci?c PV array have been done to assess the performance of the coupled model. The simulated results are in good agreement with the experimental data in spite of the weather conditions, in which the relative errors of daily energy in four different seasons are just 1.06%e6.17%, while the average monthly energy based on the proposed model (1185.4 kWh) only deviates 4.66% from that extracted by PVsyst software (1132.6 kWh), which both verify the accuracy of the proposed model again.
关键词： Experimental validation,Performance evaluation,Photovoltaic (PV) module,Coupled electrical-thermal model
更新于2025-09-11 14:15:04
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Ferroelectric barium titanate derivatives containing Mo and Mg for transparent photovoltaic applications
摘要： Using first-principles methods, we investigate the electronic properties of the [Ba(Mo1/2,Mg1/2)O3]x-[BaTiO3]1?x solid solution derived from barium titanate as a potential candidate to be used in photovoltaic devices. Focusing on the bandgap and its origin, we study the effect of different possible Mo and Mg contents, arrangements, and phases of [Ba(Mo1/2,Mg1/2)O3]x-[BaTiO3]1?x. We find that [Ba(Mo1/2,Mg1/2)O3]0.25-[BaTiO3]0.75 is a viable candidate for use in transparent photovoltaics due to its energy bandgap of 2.6 eV in the rhombohedral phase. In all cases, [Ba(Mo1/2,Mg1/2)O3]x-[BaTiO3]1?x materials exhibit spontaneous polarization that allows the exploitation of the bulk photovoltaic effect and in principle may allow high power conversion efficiency exceeding the Shockley-Queisser limit for these materials.
关键词： ferroelectric,photovoltaic,transparent,bandgap,barium titanate
更新于2025-09-11 14:15:04
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A relational approach to understanding inhabitants’ engagement with Photovoltaic (PV) technology in homes
摘要： Photovoltaic (PV) systems have been promoted in the UK housing sector as a key strategy for meeting carbon reduction commitments by offsetting the use of the non-renewable grid energy with renewable energy. However, inhabitants are not changing their routine energy consumption practices to take advantage of off-grid day time solar energy and, in some cases, even shifting practices away from the initial intentions underlying the technology. This means that the necessary energy savings from new housing are not being achieved. In this paper, this is attributed to the variation in the provisioning of PV technology in new homes, as well as inhabitants’ engagement with and know-how of PV technologies, subject to explicit rules and policies. The key contribution of this paper is to reveal how PV technologies and inhabitants interact within different socio-technological home contexts drawing on Practice theory and ethnographic methods applied to four housing developments in England.
关键词： socio-technological,Community housing,Photovoltaic (PV),practice,energy performance gap,inhabitants
更新于2025-09-11 14:15:04
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Luminescence Image Analysis Using Finite-Element Models: Finished Solar Cell Analysis
摘要： A general computational routine which seeks cell parameters that best explain a set of luminescence imaging data is presented in this article. The routine combines Griddler, a finite-element simulator for solar cells, and tailored multivariate regression techniques. It is applied to a dataset of luminescence images from about 80 monocrystalline silicon Al back surface field solar cells with varying front metal grid contact resistance and recombination. The fitted cell parameters including contact resistance spatial distribution, saturation current densities of the wafer’s passivated regions, and under the metal contacts lead to simulated I–V characteristics that are in agreement with experimental data. The extracted contact resistance also correlates well with transmission line method measurements. In a separate study of luminescence imaging data from a multicrystalline passivated emitter rear local contacted cell (PERC) cell, this analysis routine is also compared with an alternative high spatial resolution method, yielding comparable results.
关键词： Finite element analysis,luminescence,photovoltaic cells
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA) - Manizales, Colombia (2019.5.30-2019.5.31)] 2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA) - Integration of Photovoltaic System in Low Voltage Electrical Network of the Electrical Engineering Building
摘要： The quantification of the impacts of photovoltaic system (PV) integration in the low voltage (LV) power grid is necessary for the historical evaluation of the electrical network with and without PV penetration. This paper presents the study case of the LV electrical network of a university building (Colombia), which has a 9.1 kW PV system. Specifically, the electrical variables monitored were voltages (V), frequency (f), active power (W), voltage distortion (THDv), and harmonics at the Point of Common Coupling (PCC), to determine impairments according to Std. IEEE 1547-2018. PV systems could change the RMS value of voltage at the PCC, therefore, this variable was analysed. Likewise, the frequency was analysed to corroborate the no affectation of the interconnection of the PV system to the electrical network; it is due to the absence of rotational inertia. The solar irradiation information was measured by a pyranometer and the electrical variables by an smart meter, recording the information every 10 minutes for 32 days. The above is an initial step for a comprehensive evaluation of electrical variables with PV generation and future integration of parameters for the resilience evaluation of the electric network.
关键词： harmonics,frequency,photovoltaic systems,resilience,voltage,irradiation solar,Distributed generation
更新于2025-09-11 14:15:04
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[IEEE 2019 54th International Universities Power Engineering Conference (UPEC) - Bucharest, Romania (2019.9.3-2019.9.6)] 2019 54th International Universities Power Engineering Conference (UPEC) - Design of an intelligent MPPT based on ANN using a real photovoltaic system data
摘要： Maximum power point tracking (MPPT) methods are a fundamental part in photovoltaic (PV) system design for increasing the generated power of a PV array. Whilst several methods have been introduced, the artificial neural network (ANN) is an attractive method for MPPT due to its less oscillation and fast response. However, accurate training data is a big challenge to design an optimized ANN-MPPT technique. In this paper, an ANN-MPPT technique based on a large experimental training data is proposed to avoid the system from having a high training error. Those data are collected during one year from experimental tests of a PV system installed at Brunel University, London, United Kingdom. The irradiation and temperature of weather conditions are selected as the input, and the available power at MPP from the PV system as the output of the ANN model. To assess the performance, the Perturb and Observe (P&O) and the proposed ANN-MPPT methods are simulated using a MATLAB/Simulink model for the PV system. The results show that the proposed ANN method accurately tracks the optimal maximum power point and avoids the phenomenon of drift problem, whilst achieving a higher output power when compared with P&O-MPPT method.
关键词： photovoltaic (PV),Perturb and Observe (P&O),Artificial Neural Network (ANN),Maximum power point tracking (MPPT)
更新于2025-09-11 14:15:04