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Harmonics assessment and mitigation in a photovoltaic integrated network
摘要： This paper presents a comprehensive review of harmonics dominance in PV integrated network. The findings of the review conducted for different scenarios are further supported by the results of an experimental case study exploring the dominance of harmonics in a real time PV integrated microgridunder varying solar irradiance condition. It is concluded that the level of Total Harmonic Distortions (THD) in the power system network varies in different scenarios. Some of the important scenarios are: (i) percentage of PV penetration in distribution network with respect to the types of connected load, (ii) location of PV integration, (iii) effect of harmonic resonance in power network, and (iv) varying power output of PV inverters with varying solar irradiance. A harmonic management system is finally proposed to limit the excessive harmonics in the network under different network conditions. The proposed harmonic management can be used to maintain the THD level within the standard limit and ensures the quality of energy supply to the communities.
关键词： Solar irradiance,Harmonic resonance,Photovoltaic (PV),Total harmonic distortion (THD),Microgrid (MG)
更新于2025-09-16 10:30:52
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Description of short circuit current of outdoor photovoltaic modules by multiple regression analysis under various solar irradiance levels
摘要： Short-circuit current (ISC) values of test photovoltaic (PV) modules, i.e., multi-crystalline silicon, heterostructure-with-intrinsic-thin-layer, single-crystalline silicon back-contact, CuInSe2 (CIS), and CdTe modules, are descripted using multiple regression analysis based on environmental factors (solar irradiance, average photon energy (APE), and module temperature (Tmod)) under several solar irradiance levels. The APE is an index of the solar spectral irradiance distribution. PV module irradiance sensor is used to investigate simultaneous solar irradiance (PVMS), single-crystalline silicon PV module, (IrrTPVMS). It is disclosed that ISC is primarily determined by IrrTPVMS. Error between the estimated ISC and measured ISC of test PV modules is investigated. Consequently, precise ISC description (low error) is obtained when IrrTPVMS is utilized. The more precise description of the ISC for CIS and CdTe PV modules, having the bandgap (Eg) different from PVMS, is realized when adding APE environment factor even under low IrrTPVMS ((cid:1)0 kW/m2), accumulated on both sunny day and cloudy day suggesting the enhancement of investigation opportunity. This is because APE minimizes spectral mismatch error caused by Eg difference between PVMS and test PV module. Moreover, the precision of ISC description is further increased under enhanced IrrTPVMS of (cid:1)0.5 kW/m2 (on sunny day) due to stable solar irradiance.
关键词： Multiple regression analysis,Solar irradiance levels,PV module irradiance sensor,Short-circuit current
更新于2025-09-12 10:27:22
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Optimal Cost of a Solar Photovoltaic System for a Remote House in Bihar
摘要： Energy plays a vital role for the growth of a country. Solar energy is the most important renewable energy resources that can play vital role in the replacement of fossil resources to generate clean energy. Due to technological developments in solar power technologies, solar energy can be used for cooling, heating, and daily electricity demand of the world and emerged as viable alternative to produce clean energy in future. The paper describes the technological development of PV model, its present status and future opportunities in the context of Bihar, India. The study was carried out in Bihar, global solar radiation data is required for the calculation and assessment of the working principles of PV system installed at remotely located house to provide adequate power backup. The case study has been based on the solar radiation data available in Bihar, India, the cost of a suitable PV model for a house has been computed based on the analysis of power requirement of a houses in a day.
关键词： Solar Energy,Solar Radiation,Solar Irradiance,Photovoltaic (PV) system
更新于2025-09-12 10:27:22
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[IEEE 2019 International Conference on Smart Energy Systems and Technologies (SEST) - Porto, Portugal (2019.9.9-2019.9.11)] 2019 International Conference on Smart Energy Systems and Technologies (SEST) - Comparative Study of Sky Diffuse Irradiance Models Applied to Photovoltaic Systems
摘要： The increasing energy demand and the search for greener energy resources are expanding interests on photovoltaic systems. These systems need an accurate climatic and irradiation data in order to precisely estimate the energy yield of PV systems. However, most of the available irradiance data, are only for the horizontal plane. The precise estimation of the total irradiance incident on the surface of photovoltaic modules is one of the most important steps in the performance analysis of PV systems. In order to estimate the irradiance on a tilted surface from the irradiance data on the horizontal plane, there are many models available in the literature, they can be classi?ed in isotropic and anisotropic models. This study aims to access the performance of an isotropic and three anisotropic models, which are used by PV system simulation softwares, and the impact of each of them on the estimated energy generation. The results are compared with measured energy data collected at Politec?, Arac?ariguama in Brazil. Results showed that positioning the module at the correct tilted angle and facing north can optimise the global irradiance incident on the module’s surface. Hay & Davies model presented the lowest Mean Bias Error and Root Mean Squared Error while also showing a correlation coef?cient close to 1.
关键词： Sky diffuse models,Solar irradiance,Isotropic model,Anisotropic models,Photovoltaic systems
更新于2025-09-12 10:27:22
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Field Demonstration Of A Nanophotonics Enabled Solar Membrane Distillation Reactor For Desalination
摘要： Nanophotonics Enhanced Solar Membrane Distillation (NESMD) is a highly innovative process that overcomes the intrinsic limitation of membrane distillation (MD) in energy consumption, thermal efficiency, and scalability. It applies nanophotonic materials based photothermal coating on a commercial PTFE membrane surface. The coating serves as a solar-thermal collector, absorbs sunlight, and generates highly localized heat, while the rest of the membrane performs the MD function. In the current work, an original pilot-scale NESMD reactor was designed, developed, built and tested at 29.7174° N, 95.4018° W to investigate the capability of NESMD reactor to desalinate 40 g/l NaCl solution under different intensities of solar irradiance. The preliminary experimental data showed a 99.8% salt removal with a water flux ranging between 0.12 LMH (Liter/m2 hr) at 88 W/m2 (cloudy condition) and 0.77 LMH (Liter/m2 hr) at 1012 W/m2 with an average water flux of 0.55 LMH without energy recovery. Further investigations and improvements are required to enhance the performance of the reactor since it is still a new technology.
关键词： thermal efficiency,water flux,Solar membrane distillation,photothermal coating,solar irradiance
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE International Conference on Automatic Control and Intelligent Systems (I2CACIS) - Selangor, Malaysia (2019.6.29-2019.6.29)] 2019 IEEE International Conference on Automatic Control and Intelligent Systems (I2CACIS) - Limiting THD of Grid Connected Photovoltaic System using PWM Switching Frequency Selection Based on Solar Irradiance Changing
摘要： Photovoltaic (PV) system becomes the best alternative energy to produce electricity that can replace fuel resource. Grid Connected Photovoltaic (GC-PV) system will supply the AC power generated to the utility grid then distributed to the consumer. Solar irradiance in Malaysia varies daily and throughout the year. The consequence of low irradiance level is the output of the PV array is low and thus the input of the inverter relatively becoming low. The inverter will exhibit large non-linearity when the inverter is operating at low power input during low level of solar irradiance and Total Harmonic Distortion (THD) will increased. Pulse Width Modulation (PWM) techniques that are Continuous Pulse Width Modulation (CPWM) and Discontinuous PWM (DPWM) are implemented in the inverter control of the GC-PV system using MATLAB/Simulink environment to investigate the effect of switching frequency on THD at different level of solar irradiance. THD is limit within standard requirement by selecting appropriate value of switching frequency. Results shows that CPWM has better performance in THD and switching losses at selected switching frequency.
关键词： total harmonic distortion,inverter,pulse width modulation,switching frequency,grid connected photovoltaic,solar irradiance
更新于2025-09-11 14:15:04
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Solar irradiance estimations for modeling the variability of photovoltaic generation and assessing violations of grid constraints: A comparison between satellite and pyranometers measurements with load flow simulations
摘要： Global horizontal irradiance (GHI) is typically used to model the power output of distributed photovoltaic (PV) generation. On the one hand, satellite estimations are nonpervasive and already available from commercial providers, but they have a limited spatiotemporal resolution. On the other hand, local estimations, e.g., from pyranometers, sky-cameras, and monitored PV plants, capture local irradiance patterns and dynamics, but they require in situ monitoring infrastructure and upgrading the asset of electrical operators. Considering that in most power systems, PV generation is typically the aggregated contribution of many distributed plants, are local GHI estimations necessary to characterize the variability of the power ?ow at the grid connection point (GCP) and detect violations of the limits of voltages and line currents accurately? To reply, we consider GHI measurements from a dense network of pyranometers (used to model the ground truth GHI potential), satellite estimations for the same area, and information about a medium and low voltage distribution system. We perform load ?ows at different levels of installed PV capacity and compare the nodal voltages, line currents, and the power at the GCP when the irradiance is from pyranometers and when from satellite estimations, deriving conclusions on the necessity, or not, of highly spatiotemporally resolved irradiance estimations.
关键词： solar irradiance,grid constraints,satellite measurements,pyranometers,load flow simulations,photovoltaic generation
更新于2025-09-11 14:15:04
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A Long-Term Dissipation of the EUV He?ii (30.4 nm) Segmentation in Full-Disk Solar Images
摘要： Some quiet-Sun days observed by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) during the time interval in 2010 – 2017 were used to continue our previous analyses reported by Didkovsky and Gurman (Solar Phys. 289, 153, 2014a) and Didkovsky, Wieman, and Korogodina (Solar Phys. 292, 32, 2017). The analysis consists of determining and comparing spatial spectral ratios (spectral densities over some time interval) from spatial (segmentation-cell length) power spectra. The ratios were compared using modeled compatible spatial frequencies for spectra from the Extreme ultraviolet Imaging Telescope (EIT) on-board the Solar and Heliospheric Observatory (SOHO) and from AIA images. With the new AIA data added to the EIT data we analyzed previously, the whole time interval from 1996 to 2017 reported here is approximately the length of two “standard” solar cycles (SC). The spectral ratios of segmentation-cell dimension structures show a signi?cant and steady increase with no detected indication of SC-related returns to the values that characterize the SC minima. This increase in spatial power at high spatial frequencies is interpreted as a dissipation of medium-size EUV network structures to smaller-size structures in the transition region. Each of the latest ratio changes for 2010 through 2017 spectra calculated for a number of consecutive short-term intervals has been converted into monthly mean ratio (MMR) changes. The MMR values demonstrate variable sign and magnitudes, thus con?rming the solar nature of the changes. These changes do not follow a “typical” trend of instrumental degradation or a long-term activity pro?le from the He II (30.4 nm) irradiance measured by the Extreme ultraviolet Spectrophotometer (ESP) either. The ESP is a channel of the Extreme ultraviolet Variability Experiment (EVE) on-board SDO.
关键词： Solar cycle, observations,Solar irradiance,Granulation
更新于2025-09-10 09:29:36
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[IEEE 2018 International Joint Conference on Neural Networks (IJCNN) - Rio de Janeiro (2018.7.8-2018.7.13)] 2018 International Joint Conference on Neural Networks (IJCNN) - Estimation of global solar irradiance with LDR sensor and artificial neural network embedded in an 8-bit microcontroller
摘要： This work deals with the estimation of global solar irradiance in an embedded platform through the use of a Light Dependent Resistor (LDR) sensor and its temperature. A prototype is built and has its values compared to the data obtained through a commercial pyranometer. An Multilayer Perceptron neural network is used to provide a non-linear regression between the voltage and temperature signals of the LDR on the commercial sensor irradiance data in a data analysis software. A regression with determination coef?cient of 96.466 % and with mean squared error of 0.04 was obtained. The neural network present in the embedded system has 100% accuracy in relation to the neural network present in the data analysis software used. The minimum response time of the prototype is 13.49 ms and its dissipated power is 27.2 mW, making the approach quite promising. This neural estimation, using simple sensors like the LDR, can help to reduce the cost of renewable energy applications and make it easier to implement.
关键词： solar irradiance,renewable energies,nonlinear regression,embedded systems,light dependent resistor,multilayer perceptron
更新于2025-09-10 09:29:36
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An Ensemble Framework For Day-Ahead Forecast of PV Output in Smart Grids
摘要： The uncertainty associated with solar photo-voltaic (PV) power output is a big challenge to design, manage and implement effective demand response and management strategies. Therefore, an accurate PV power output forecast is an utmost importance to allow seamless integration and a higher level of penetration. In this research, a neural network ensemble (NNE) scheme is proposed, which is based on particle swarm optimization (PSO) trained feedforward neural network (FNN). Five different FFN structures with varying network complexities are used to achieve the diverse and accurate forecast results. These results are combined using trim aggregation after removing the upper and lower forecast error extremes. Correlated variables namely wavelet transformed historical power output of PV, solar irradiance, wind speed, temperature and humidity are applied as inputs to the multivariate NNE. Clearness index is used to classify days into clear, cloudy and partial cloudy days. Test case studies are designed to predict the solar output for these days selected from all seasons. The performance of the proposed framework is analyzed by applying training data set of different resolution, length and quality from seven solar PV sites of the University of Queensland, Australia. The forecast results demonstrate that the proposed framework improves the forecast accuracy significantly in comparison with individual and benchmark models.
关键词： clear day (CD),solar irradiance,cloudy day (CLD),clearness index,PV power output forecasting,ensemble network (EN),neural network ensemble (NNE),partially cloudy day (PCD),particle swarm optimization
更新于2025-09-10 09:29:36