Control techniques for enhancing performance of PV system under dynamic conditions

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Md Ehtesham ◽  
Majid Jamil
Keyword(s):  
Power Quality ◽  
Research Work ◽  
Environmental Parameters ◽  
Original Research ◽  
State Variables ◽  
Estimation Of Parameters ◽  
Pv System ◽  
Partial Shading ◽  
Content Type ◽  
Dynamic Conditions

Purpose The purpose of this paper is to focus on two major areas of concern for the Photovoltaic (PV) system, i.e. power quality and maximum power point tracking (MPPT). Novel control strategies have been proposed for both these issues, and their respective superiorities over the existing techniques have been established. On the other hand, as far as MPPT is concerned, two limitations are found in the available techniques. One is the inability of effective MPPT in dynamic conditions where the environmental parameters changes very rapidly. Second one is the ineffective tracking of global maxima under partial shading conditions. Design/methodology/approach Here, modified Kalman filtering approach has been applied for estimating the reference current of active power filter, incorporated for power quality improvement. The proposed Kalman algorithm introduces a weighted matrix, which advances the estimated values of state variables. This paper presents a simple and enhanced model-based (MB) MPPT algorithm that has the capability of tracking MPPT effectively in both these working conditions. The proposed MB algorithm uses the mathematical modelling, and based on precised estimation of parameters, it pre-determines the MPP analytically. Findings It has been tested successfully for dynamic variations of insolation, temperature and partial shading, where all these three parameters are rigorously varied over the full scale of practical values. The results have been also investigated experimentally and compared with the simulated one. A close matching of both the results has been shown through the plots, which validates the effectiveness of proposed algorithms. Originality/value This research paper is part of the original research work carried out in Lab. Simulated results are obtained in MATLAB/Simulink platform, whereas these are further validated experimentally on 2-KW panel constituted with all types of commercial products, namely, mono, poly and thin-film.

scholarly journals Enhanced model based algorithm to reinforce PV system with dynamic MPPT capability

2021 ◽  
Vol 10 (3) ◽  
pp. 261
Author(s):  
Md Ehtesham
Keyword(s):  
Rapid Change ◽  
Environmental Parameters ◽  
Green Energy ◽  
Operating Conditions ◽  
Time Data ◽  
Pv System ◽  
Partial Shading ◽  
Efficient System ◽  
Dynamic Conditions ◽  
Model Based

<p>Photovoltaic (PV) power has emerged as the most attractive resource in form of a clean and green energy. However, one major challenge associated with PV interfacing is its intermittent output characteristic which varies dramatically with the operating conditions. Thus designing an effective maximum power point tracking (MPPT) algorithm is a key aspect for optimizing PV system performance. Numerous MPPT algorithms have been proposed earlier having their own specific advantages. However, these are found to have two major limitations which have to be essentially addressed. Firstly, they become ineffective in the dynamic conditions where there is rapid change in environmental parameters like insolation and temperature. Secondly, they fail to discriminate between global and local peaks under partial shading conditions. Therefore, to achieve a reliable and efficient system operation, this paper presents an enhanced model-based (MB) algorithm that overcomes both these deficiencies. Based on new governing equations and precised estimation technique, it predetermines the MPP analytically. First simulated results are obtained where it is tested for dynamic variations of all the three parameters. Then the experimental validation is carried out on a 2 KW installed panel where real time data is recorded through CR1000 data logger and environmental parameters are sensed with elements like pyranometer and humidity sensor. A large number of experimental results are obtained for tracked MPP in the dynamic conditions, which are then summarized in tabular forms. These are finally plotted and compared with simulated results to illustrate the effectiveness of proposed MB algorithm.</p>

scholarly journals Different Techniques to Mitigate Partial Shading in Photovoltaic Panels

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3863
Author(s):  
Tiago Alves ◽  
João Paulo N. Torres ◽  
Ricardo A. Marques Lameirinhas ◽  
Carlos A. F. Fernandes
Keyword(s):  
Cell Model ◽  
Research Work ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Pv System ◽  
Partial Shading ◽  
System Architectures ◽  
Pv Systems ◽  
Advantages And Disadvantages ◽  
Pv Panel

The effect of partial shading in photovoltaic (PV) panels is one of the biggest problems regarding power losses in PV systems. When the irradiance pattern throughout a PV panel is inequal, some cells with the possibility of higher power production will produce less and start to deteriorate. The objective of this research work is to present, test and discuss different techniques to help mitigate partial shading in PV panels, observing and commenting the advantages and disadvantages for different PV technologies under different operating conditions. The motivation is to contribute with research, simulation, and experimental work. Several state-of-the-artsolutions to the problem will be presented: different topologies in the interconnection of the panels; different PV system architectures, and also introducing new solution hypotheses, such as different cell interconnections topologies. Alongside, benefits and limitations will be discussed. To obtain actual results, the simulation work was conducted by creating MATLAB/Simulink models for each different technique tested, all centered around the 1M5P PV cell model. The several techniques tested will also take into account different patterns and sizes of partial shading, different PV panel technologies, different values of source irradiation, and different PV array sizes. The results will be discussed and validated by experimental tests.

Active thermography as a tool for internal composite structure observation and evaluation

2018 ◽  
Vol 9 (6) ◽  
pp. 779-792 ◽  
Author(s):  
Katarzyna Majewska ◽  
Magdalena Mieloszyk ◽  
Wieslaw Ostachowicz
Keyword(s):  
Research Work ◽  
Structural Condition ◽  
Original Research ◽  
Pulsed Thermography ◽  
Content Type ◽  
Three Samples ◽  
Structure Observation ◽  
Material Discontinuities ◽  
Excellent Tool ◽  
Composite Samples

Purpose The purpose of this paper is to study if it is possible applying infrared thermography (both vibro and pulsed) to detect and localise material discontinuities as well as to find the place where the inclusion was introduced. Design/methodology/approach The experimental investigation is performed on samples manufactured during infusion process. The measurements were performed on three four-layered rectangular composite samples with discontinuities. The discontinuities introduced in the samples were as follow: all three samples between first and second layer counting form the bottom two optical fibres (OFs) were embedded and additionally: sample no. 1 – one of the OF was broken, sample no. 2 – the drop of water was introduced, and sample no. 3 – the little amount of dust was introduced. Findings For some discontinuities, the vibrothermography is excellent tool (placement of broken OF, drop of water), for same is not sufficient (healthy OFs or dust). For dust, the pulsed thermography seems to be the required tool. Different approaches (vibrothermography and pulsed thermography) for the same sample will confirm that for same defects vibrothermograpy is better and for some pulsed thermography – complex combination of different thermography approaches is needed to have complex response about sample structural condition. Originality/value The presented paper is an original research work. There are very limited literature papers applying both vibro and pulsed thermography for one problem. The assessment of different discontinuities (inclusions) and detailed analysis is presented.

System and neural network analysis of intent to buy and willingness to pay insurance premium

2019 ◽  
Vol 45 (1) ◽  
pp. 147-168 ◽  
Author(s):  
Sanjay Tolani ◽  
Ananth Rao ◽  
Genanew B. Worku ◽  
Mohamed Osman
Keyword(s):  
Neural Network ◽  
Social Security ◽  
Willingness To Pay ◽  
United Arab Emirates ◽  
Middle Eastern ◽  
Country Of Origin ◽  
Research Work ◽  
Original Research ◽  
Content Type ◽  
Social Security Benefits

Purpose The purpose of this paper is to analyze significant determinants to assess the probability of insureds’ intent to buy (ITB) insurance and willingness to pay (WTP) quantum of dollars for security benefits. Design/methodology/approach The authors use the Double Hurdle Model (DHM) and Neural Network (NN) architecture to analyze the insureds’ behavior for ITB and WTP. The authors apply these frameworks to all the 503 insureds of a branch of a leading insurer in the United Arab Emirates. Findings The DHM identified age, loans & liabilities, body mass index, travel outside the UAE, salary and country of origin (Middle Eastern and African) as significant determinants to predict WTP for social security benefits. In addition to these determinants, NN architecture identified insurance replacement, holding multiple citizenship, age of parents, mortgages, country of origin: Americas, length of travel, income of previous year and medical conditions of insured as additional important determinants to predict WTP for social security benefits; thus, NN is found to be superior to DHM due to its lowest RMSE and AIC in the holdout sample and also its flexibility and no assumptions unlike econometric models. Research limitations/implications Insureds’ data used from one UAE Branch limit the generalizability of empirical findings. Practical implications The study findings will enable the insurers to appropriately design the insurance products that match the insurers’ behavior of ITB and WTP for social security benefits. Social implications The study findings have the potential for insurance institutions to be more flexible in their insurance practices through public–private partnerships. Originality/value This is the authors’ original research work.

On bio-convection thermal radiation in Darcy – Forchheimer flow of nanofluid with gyrotactic motile microorganism under Wu’s slip over stretching cylinder/plate

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
H. Waqas ◽  
M. Imran ◽  
Taseer Muhammad ◽  
Sadiq M. Sait ◽  
R. Ellahi
Keyword(s):  
Mixed Convection ◽  
Volume Fraction ◽  
Research Work ◽  
Concentration Field ◽  
Second Order ◽  
Original Research ◽  
Stretching Cylinder ◽  
Content Type ◽  
Mixed Convection Parameter ◽  
Convection Parameter

Purpose The purpose of this study is to discuss the Darcy–Forchheimer nanoliquid bio-convection flow by stretching cylinder/plate with modified heat and mass fluxes, activation energy and gyrotactic motile microorganism features. Design/methodology/approach The proposed flow model is based on flow rate, temperature of nanomaterials, volume fraction of nanoparticles and gyrotactic motile microorganisms. Heat and mass transport of nanoliquid is captured by the usage of popular Buongiorno relation, which allows us to evaluate novel characteristics of thermophoresis diffusion and Brownian movement. Additionally, Wu’s slip (second-order slip) mechanisms with double stratification are incorporated. For numerical and graphical results, the built-in bvp4c technique in computational software MATLAB along with shooting technique is used. Findings The influence of key elements is illustrated pictorially. Velocity decays for higher magnitude of first- and second-order velocity slips and bioconvection Rayleigh number. The velocity of fluid has an inverse relation with mixed convection parameter and local inertia coefficient. Temperature field enhances with the increase in estimation of thermal stratification Biot number and radiation parameter. A similar situation for concentration field is observed for mixed convection parameter and concentration relaxation parameter. Microorganism concentration profile decreases for higher values of bioconvection Lewis number and Peclet number. A detail discussion is given to see how the graphical aspects justify the physical ones. Originality/value To the best of the authors’ knowledge, original research work is not yet available in existing literature.

Characterization of the mechanical behaviour of wooden construction materials from “quinta lobeira de cima”

2018 ◽  
Vol 9 (3) ◽  
pp. 396-410 ◽  
Author(s):  
Patricia Raposo ◽  
João Martins ◽  
José Correia ◽  
Maria E. Salavessa ◽  
Cristina Reis ◽  
...  
Keyword(s):  
Twentieth Century ◽  
Mechanical Behaviour ◽  
Research Work ◽  
Construction Materials ◽  
Image Correlation ◽  
Original Research ◽  
Content Type ◽  
Cultural Patrimony ◽  
Master Thesis ◽  
Longitudinal Modulus

Purpose The antique structures are part of the inheritance that our elders left, being important to preserve their memories. It is important to preserve, rehabilitate and restore the historic buildings protecting the cultural patrimony, attending to the actual comfort and habitability requirements. It is necessary to study the behaviour of the various elements that compose antique structures (masonry and wood) in order to develop assessment measures according to the characteristics of the original materials. The paper aims to discuss these issues. Design/methodology/approach An experimental campaign to characterize the mechanical behaviour of the wood of the roof of the “sequeiro” of “Quinta Lobeira de Cima”, a building from the twentieth century located in Minho, was carried out. The tested wood specimens are from two different species: chestnut and oak. Compression, tension and static flexion tests according to parallel to the grain direction were performed. Other parameters, such as density, moisture content and longitudinal modulus of elasticity in compression and in tension, were also obtained. The measurement of displacements was made with Digital Image Correlation (DIC). Findings The results of this study show the similarity between experimental and empirical values for the studied woods species. Originality/value This original study aimed at characterizing the mechanical properties using DIC of wood of the roof of the “sequeiro” of “Quinta Lobeira de Cima”, a building from the twentieth century located in Minho (Portugal). This study is part of master thesis of João Martins, an original research work.

scholarly journals Entire functions of restricted hyper-order sharing a set of two small functions IM with their linear c-shift operators

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abhijit Banerjee ◽  
Arpita Roy
Keyword(s):  
Entire Function ◽  
Entire Functions ◽  
Shift Operator ◽  
Research Work ◽  
Original Research ◽  
Exponent Of Convergence ◽  
Content Type ◽  
Shift Operators ◽  
Small Functions ◽  
Hyper Order

PurposeThe paper aims to build the relationship between an entire function of restricted hyper-order with its linear c-shift operator.Design/methodology/approachStandard methodology for papers in difference and shift operators and value distribution theory have been used.FindingsThe relation between an entire function of restricted hyper-order with its linear c-shift operator was found under the periphery of sharing a set of two small functions IM (ignoring multiplicities) when exponent of convergence of zeros is strictly less than its order. This research work is an improvement and extension of two previous papers.Originality/valueThis is an original research work.

Investigation and modeling of lean six sigma barriers in small and medium-sized industries using hybrid ISM-SEM approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahipal Singh ◽  
Rajeev Rathi
Keyword(s):  
Six Sigma ◽  
Structural Equation ◽  
Research Work ◽  
Lean Six Sigma ◽  
Equation Modeling ◽  
Original Research ◽  
Extensive Literature ◽  
Implementation Barriers ◽  
Interpretive Structural Modeling ◽  
Content Type

Purpose Lean six sigma (LSS) has attained a prominent position in mature organizations but small- and medium-sized enterprises (SMEs) are struggling in the proper implementation of LSS in their core business. This study aims to make a comprehensive analysis of LSS implementation barriers in SMEs so that LSS execution can be much fluent in SMEs. Design/methodology/approach This research work is carried out based on investigation of LSS barriers through extensive literature review. For validating the identified barriers, a questionnaire survey was conducted, and out of 400 samples, 260 responses received back. The collected responses are analyzed statistically and found 16 significant barriers. The finalized barriers are modeled using interpretive structural modeling (ISM) and clustered them through matrice d’impacts croisés-multiplication appliquée a un classement (MICMAC) analysis. Furthermore, to check the consistency of results, ISM-MICMAC outcomes are validated through structural equation modeling (SEM). Findings The result reveals that 16 LSS implementation barriers are finalized through expert’s opinion and validated through statistical reliability test with Cronbach’s alpha value of 0.820. The ISM model reveals that the management relevant barriers are exhibiting the leading role to influence the implementation of LSS in SMEs. Moreover, the obtained results validated through SEM are found in good agreement. Research limitations/implications During pairwise comparisons, there may be some prejudice and subjectivity as human judgments are engaged. Practical implications This study provides impetus to practitioners and consultant for the initiation of LSS in the business organization through tackling the LSS barriers as per their driving and dependence power. Originality/value In the past, limited studies had explored the LSS barriers, but a few studies analyzed the mutual relationship between barriers. No such study is reported in literature that validates the mutual interaction model of LSS barriers. Hence, this paper presents the original research work of identification and modeling of barriers associated with LSS implementation in SMEs through hybrid ISM-SEM approach.

Use of vibration measurements in health monitoring of reinforced concrete buildings

2010 ◽  
Vol 1 (3) ◽  
pp. 209-232 ◽  
Author(s):  
Varinder S. Kanwar ◽  
Naveen Kwatra ◽  
Pankaj Aggarwal ◽  
Ramesh P. Singh
Keyword(s):  
Reinforced Concrete ◽  
Natural Hazards ◽  
Structural Damage ◽  
Research Work ◽  
Original Research ◽  
Cement Concrete ◽  
Vibration Measurements ◽  
Content Type ◽  
Concrete Buildings ◽  
Reinforced Cement

PurposeIn developing countries such as India, it is common practice to use low‐quality building materials, the strength of such materials reduce with time, which affects the lifespan of buildings. The wind, rain, seepage, and surface runoff are other key factors responsible for building damage and exterior degradation. The increasing industrial growth in and around urban areas is responsible for increasing industrial and anthropogenic emissions that are found to accelerate degradation of the buildings that affects their physical appearance. In an area prone to natural hazards such as earthquakes, volcanoes, subsidence, floods, lightning, tornados, and cyclone/hurricanes, huge amounts of damage throughout the globe has been experienced. For the purpose of assuring safety due to natural hazards, it is necessary to monitor the damage for its existence, its location and extent. Undetected damage may potentially lead to risk of vulnerability caused by natural hazards and eventually to catastrophic failure. Hence, rapid structural damage detection is essential and important to save human life due to failure of structures or buildings. Most of the time, human loss occurs due to damage to the buildings. This paper aims to address these issues.Design/methodology/approachIn the present study, numerous experiments have been carried out on two reinforced concrete building test specimens and on seven existing reinforced cement concrete structures.FindingsThe results presented here in this study show that the vibration measurements can be used to monitor the health of framed reinforced cement concrete buildings.Originality/valueThe present study is part of doctoral thesis of Varinder S. Kanwar, an original research work.

THz spectroscopy for inspection and evaluation of internal structure of sandwich samples

2018 ◽  
Vol 9 (6) ◽  
pp. 793-803 ◽  
Author(s):  
Magdalena Mieloszyk ◽  
Katarzyna Majewska ◽  
Wieslaw Ostachowicz
Keyword(s):  
Internal Structure ◽  
Research Work ◽  
Mechanical Damage ◽  
Thz Spectroscopy ◽  
Original Research ◽  
Content Type ◽  
Complex Samples ◽  
Water Detection ◽  
Internal Structures ◽  
Honeycomb Filler

Purpose The purpose of this paper is to discuss the application of THz spectroscopy for the inspection and evaluation of the internal structure of complex samples with honeycomb fillers. Design/methodology/approach Three complex samples with honeycomb fillers are investigated using THz spectrometer in order to determine the applicability of chosen non-destructive method for the analysis of internal structure of structural components. The first analysed sample has aluminium honeycomb filler with some cells filled with water. The aim of the analysis is to distinguish empty and full cells. The other two sandwich samples are made of different non-metallic components and for them the possibility of THz spectroscopy application is analysed. Findings The empty and full cells in metal honeycomb filler were easily distinguished due to different absorption coefficients of electromagnetic waves in THz range for air and water. It was especially visible for frequency domain. The THz spectroscopy was able to inspect the non-metallic samples internal structures and distinguish skins (with layers), honeycomb fillers and adhesive layers between them. It was also possible to detect, localise and determine the size of a local damage of honeycomb walls due to impact influence. Originality/value The present study is an original research work. There are very limited literature papers which present analyses of internal structures of sandwich elements using THz spectroscopy and investigate utility of the method for mechanical damage and contamination (water) detection and localisation.

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