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Tytuł:
Simulation of the impact of the degree and type of shading on generation of electrical energy by the PV system in MATLAB&SIMULINK environment
Autorzy:
Jarmuda, T.
Powiązania:
https://bibliotekanauki.pl/articles/97511.pdf
Data publikacji:
2015
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
PV system
poor shading effect
strong shading effect
bypass diodes
MATLAB environment
Opis:
In the study the method of modelling of the photovoltaic system (PV) in MATLAB & SIMULINK environment was presented along with test results of the impact of shading on the value of energy output from the photovoltaic system. The PV system model constructed of five parallel connected photovoltaic panels of TPSM6U type was proposed. Simulation tests were conducted considering the effect of poor and strong shading of panels causing differences in the density of the radiation power (irradiance) for individual panels and the PV system. The values of electrical energy generated by individual PV panels and the whole photovoltaic system were determined for the purposes of the actual forces. Optional switching on and off of the bypass diodes was considered in the photovoltaic panels. The tests were developed and final conclusions were formulated.
Źródło:
Computer Applications in Electrical Engineering; 2015, 13; 454-468
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of shading on solar cell electrical parameters
Autorzy:
Swatowska, B.
Panek, P.
Powiązania:
https://bibliotekanauki.pl/articles/173520.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
solar cells
shading
electrical parameters
efficiency
Opis:
Availability of light to solar cells is crucial for the efficiency of photovoltaic systems. For this reason, even partial shading can result in significant reduction of generated electric power (loss of current). This paper examines the changes in the efficiency of multicrystalline silicon solar cells which are caused by different kinds of shading. Full and partial shading were simulated by the use of three types of shutter-foils printed in a gray and black scale. The measurements of current-voltage characteristics show that totally or partially shaded modules can drastically reduce the generated power. Short circuit current decreases from about 8100 to 100 mA that in the case of the series connection of cells in a module, lead to the shift of the point of the maximum power and finally to the considerable reduction of nominal system photovoltaic power.
Źródło:
Optica Applicata; 2017, 47, 2; 319-323
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Shape From Shading Technique for Side Scan Sonar Images
Autorzy:
Bikonis, K.
Moszynski, M.
Lubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/258963.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
side scan sonar data processing shape from shading
Opis:
Digital signal processing technology has revolutionized a way of processing, visualisation and interpretation of data acquired by underwater systems. Through many years side scan sonars were one of the most widely used imaging systems in the underwater environment. Although they are relatively cheap and easy to deploy, more powerful sensors like multibeam echo sounders and sonars are widely used today and deliver 3D bathymetry of sea bottom terrain. Side scan sonar outputs data usually in a form of grey level 2D acoustic images but the analysis of such pictures performed by human eye allows creating semi-spatial impressions of seafloor relief and morphology. Hence the idea of post-processing the side scan sonar data in a manner similar to human eye to obtain 3D visualisation. In recently developing computer vision systems the shape from shading approach is well recognized technique. Applying it to side scan sonar data is challenging idea used by several authors. In the paper, some further extensions are presented. They rely on processing the backscattering information of each footprint (pixel in sonar image) along with its surroundings. Additionally, a current altitude is estimated from the size of shadow areas. Both techniques allow constructing 3D representation of sea bottom relief or other investigated underwater objects.
Źródło:
Polish Maritime Research; 2013, 3; 39-44
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ kierunku iluminacji na wyniki geologicznej interpretacji DEM-przykłady z Karpat Zachodnich
Effect of direction of sun shading on geological interpretation of DEM - examples from the Weastern Carpathians
Autorzy:
Ozimkowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/2074811.pdf
Data publikacji:
2010
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
DEM
lineamenty
iluminacja
Karpaty
lineaments
sun shading
Carpathians
Opis:
The paper presents results of comparison of 2 sets of geological interpretations of the same DEM (Digital Elevation Model), obtained with 2 different, perpendicular sun shading directions (N and E). Lineaments perpendicular to sun shading direction are at least 10 times better visible than lineaments parallel to it but this influence is visible only at relatively narrow angles. In turn, lineaments situated between ca. 25–65° from sun shading direction show no such influence so they fit to statistical purposes.
Źródło:
Przegląd Geologiczny; 2010, 58, 9/2; 862-866
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ ekranów cieniujących na warunki świetlne w tunelu foliowym
Effect of shading screens on light conditions in a film tunnel
Autorzy:
Latała, H.
Powiązania:
https://bibliotekanauki.pl/articles/287892.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
ekran cieniujący
promieniowanie PAR
shading screens
PAR distribution
Opis:
Badania wykonano w tunelu foliowym o powierzchni 54 m2 ustawionym dłuższą osią wschód zachód. Pokrycie obiektu stanowiła folia polietylenowa. Obiekt wyposażony był w przesuwne ekrany cieniujące wykonane z tkaniny pokrytej w 50 % paskami z folii aluminiowej. Poziom natężenia promieniowania fotosyntetycznie czynnego (PAR) zarówno wewnątrz jak i na zewnątrz tunelu określane było przy użyciu fitifotometrów. W wyniku przeprowadzonych badań przedstawiono rozkład natężenia promieniowania PAR wewnątrz tunelu w różnych warunkach radiacji na zewnątrz. W warunkach wykonywanego doświadczenia obliczono procentowy stopień tłumienia promieniowania PAR. Stwierdzono istotny wpływ zastosowanych ekranów cieniujących na intensywność światła dostępnego dla roślin.
The tests were carried out in a film tunnel of 54 m2 area with its longer axis positioned on the E – W line. The structure was covered with polyethylene film. The structure was equipped with sliding shading screens made of fabric, covered with strips of aluminium foil in 50 %. The intensity of photosynthetically active radiation (PAR), both inside and outside the tunnel was determined with the aid of fito-photometers. As a result of the tests made, the distribution of PAR intensity inside the tunnel has been demonstrated. In the experiment made, the percentage of PAR suppression has been calculated. Considerable influence of the applied shading screens on the intensity of light reaching the plants has been found.
Źródło:
Inżynieria Rolnicza; 2005, R. 9, nr 7, 7; 109-118
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Maximizing power output of a partially shaded total-cross-tied photovoltaic array
Autorzy:
Shah, N. S.
Patel, H. H.
Powiązania:
https://bibliotekanauki.pl/articles/136262.pdf
Data publikacji:
2017
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
current compensation
voltage equalization
MPPT
partial shading
TCT configuration
Opis:
Non-uniform conditions on the modules of the PV array, especially, partial shading reduces the output of the PV array to a large extent. The shaded module in a string limits the current of the entire string and hence, the output power of the string. The output power under such conditions is reported to be higher for total-cross-tied (TCT) configuration. This paper describes two different approaches, one based on current compensation (current equalization) and another based on voltage equalization, to extract higher power from the partially shaded total-cross-tied photovoltaic array. The TCT configuration is considered to minimize the number of converters, sensors, cost and complexity involved. The additional converters in the two distinct approaches evaluated here operate only when the partial shading occurs and are controlled to minimize the current and voltage miss-matches. The analysis and the control algorithm are presented. Simulation results obtained in MATLAB/Simulink are included to demonstrate the effectiveness of both methods and the relative merits and demerits of these approaches are highlighted.
Źródło:
Transactions on Environment and Electrical Engineering; 2017, 2, 1; 10-18
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównanie wydajności języków cieniowania Cg i HLSL
A comparison of Cg versus HLSL shaders efficiency
Autorzy:
Dąbkowski, J.
Król, R.
Powiązania:
https://bibliotekanauki.pl/articles/290367.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
języki cieniowania
rendering
potok graficzny
shading languages
graphics pipeline
Opis:
Na podstawie zaprojektowanych dziesięciu testów szybkości wykonania identycznych programów cieniujących, jednego napisanego w języku HLSL, drugiego w języku Cg porównano wydajność tych języków w środowisku Windows XP. W zależności od rodzaju testu stwierdzono albo porównywalną wydajność obu języków albo przewagę szybkości działania programów napisanych w HLSL.
Based on ten tests especially designed for checking the execution time of two identical shading programs, one written in HLSL and the other one in Cg, there were comparisons made of the efficiency of these languages in Windows XP environment. Depending on the type of test one finds either equivalent efficiency or advantage of HLSL programs.
Źródło:
Inżynieria Rolnicza; 2010, R. 14, nr 7, 7; 41-45
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Shading of a Silvopastoral System on Microclimate and Botanical Composition of Polyphytic Pasture: A Preliminary Study in the Subtropics
Autorzy:
Vieira, Frederico Márcio C.
Militão, Érica R.
Wagner Júnior, Américo
Herbut, Piotr
Mayer, Lilian Regina R.
Vismara, Edgar S.
Vieira, Afrânio Márcio C.
Paris, Wagner
Hermes, Cátia
Paśmionka, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/2027870.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
integrated crop-livestock-forest systems
biometeorology
shading
polyphytic grassland
Opis:
The silvopasture system is an integrated system which has been widespread in tropical and sub-tropical climates. However, there is a lack of detailed studies regarding agroecological silvopasture systems. This study assessed whether the different levels of shading in an agroecological silvopastoral system influences the microclimate and botanical composition of polyphytic pasture. We used eight paddocks composed of a silvopastoral system in a subtropical climate, with different tree species arranged in simple lines with polyphytic pasture. In each paddock, we established three levels of visual shading (under the canopy, intermediate and full sun). The following microclimatic variables were recorded monthly during the daytime: illuminance, air temperature, air relative humidity, wind speed, and surface soil temperature. The samples of forages were separated into grasses, legumes and spontaneous, then fractionated into leaves, stems, and senescent material. We observed lower values of illuminance and surface soil temperature under the canopy, with differences between full sun and under the canopy at noon. Regarding the forage, the percentage of legumes was higher in full sun, and spontaneous species and leaves had high proportions under the canopy. Based on the results, the agroecological silvopastoral system changed the microclimatic characteristics and altered the plant composition of polyphytic pasture.
Źródło:
Journal of Ecological Engineering; 2021, 22, 10; 215-224
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Practical Application of An Alternative Solar Position Chart
Autorzy:
Kazimierski, S.
Powiązania:
https://bibliotekanauki.pl/articles/115582.pdf
Data publikacji:
2012
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
solar position chart
shading reduction
solar energy
solar energy assessment
Opis:
Humans, like every other living organism, are dependant on solar energy. If solar energy is to be used consciously, whether directly or stored, there is a need for precise assessment. The bigger the accuracy of the assessment, the greater the benefits of the application of solar energy will be. The simplicity and ease of application of a tool for such predictions would lead to solar energy resources assessment on a large scale. This would result in greater awareness of the potential of the sun energy and application of the solar energy on a larger scale, with all the benefits of using renewable energy resources.
Źródło:
Challenges of Modern Technology; 2012, 3, 1; 46-50
2082-2863
2353-4419
Pojawia się w:
Challenges of Modern Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A hybrid maximum power point search method using temperature measurements in partial shading conditions
Autorzy:
Mroczka, J.
Ostrowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/221430.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
maximum power point
partial shading
perturb and observe
temperature measurement
Opis:
Photovoltaic panels have a non-linear current-voltage characteristics to produce the maximum power at only one point called the maximum power point. In the case of the uniform illumination a single solar panel shows only one maximum power, which is also the global maximum power point. In the case an irregularly illuminated photovoltaic panel many local maxima on the power-voltage curve can be observed and only one of them is the global maximum. The proposed algorithm detects whether a solar panel is in the uniform insolation conditions. Then an appropriate strategy of tracking the maximum power point is taken using a decision algorithm. The proposed method is simulated in the environment created by the authors, which allows to stimulate photovoltaic panels in real conditions of lighting, temperature and shading.
Źródło:
Metrology and Measurement Systems; 2014, 21, 4; 733-740
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Can analytical shading be art? Reflections on the canvas of experiments with ArcGIS and Surfer
Autorzy:
Siwek, J.
Wacławik, W.
Powiązania:
https://bibliotekanauki.pl/articles/92496.pdf
Data publikacji:
2015
Wydawca:
Oddział Kartograficzny Polskiego Towarzystwa Geograficznego
Tematy:
digital terrain model (DTM)
analytical shading
art in cartography
GIS programs
Opis:
Despite numerous theoretical and experimental studies of analytical relief shading, devised about half a century ago, its quality has not yet reached the excellence of traditional (manual) shading. The paper discusses its basic principles and the main factors affecting the quality of shading. It also stresses the crucial importance of the digital terrain model used as the basis for shading as well as the proper generalization of the relief. Experiments with shading modules of ArcGIS and Surfer, aiming to explore the functionality of algorithms they employ, have demonstrated significant similarity of the results. In conclusion, the authors attempt to answer the question posted in the title of the article. In their view, analytical shading is not art because shading algorithms are incapable of producing the visually beautiful effects that an experienced cartographer with artistic talents can create.
Źródło:
Polish Cartographical Review; 2015, 47, 3; 121-135
2450-6974
Pojawia się w:
Polish Cartographical Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of rapid and reliable cuckoo search algorithm for global maximum power point tracking of solar PV systems in partial shading condition
Autorzy:
Bentata, Khadidja
Mohammedi, Ahmed
Benslimane, Tarak
Powiązania:
https://bibliotekanauki.pl/articles/1845518.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
photovoltaic system
maximum power point tracking
partial shading
cuckoo search algorithm
Opis:
The solar photovoltaic output power fluctuates according to solar irradiation, temperature, and load impedance variations. Due to the operating point fluctuations, extracting maximum power from the PV generator, already having a low power conversion ratio, becomes very complicated. To reach a maximum power operating point, a maximum power point tracking technique (MPPT) should be used. Under partial shading condition, the nonlinear PV output power curve contains multiple maximum power points with only one global maximum power point (GMPP). Consequently, identifying this global maximum power point is a difficult task and one of the biggest challenges of partially shaded PV systems. The conventional MPPT techniques can easily be trapped in a local maximum instead of detecting the global one. The artificial neural network techniques used to track the GMPP have a major drawback of using huge amount of data covering all operating points of PV system, including different uniform and non-uniform irradiance cases, different temperatures and load impedances. The biological intelligence techniques used to track GMPP, such as grey wolf algorithm and cuckoo search algorithm (CSA), have two main drawbacks; to be trapped in a local MPP if they have not been well tuned and the precision-transient tracking time complex paradox. To deal with these drawbacks, a Distributive Cuckoo Search Algorithm (DCSA) is developed, in this paper, as GMPP tracking technique. Simulation results of the system for different partial shading patterns demonstrated the high precision and rapidity, besides the good reliability of the proposed DCSA-GMPPT technique, compared to the conventional CSA-GMPPT.
Źródło:
Archives of Control Sciences; 2021, 31, 3; 495-526
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of rapid and reliable cuckoo search algorithm for global maximum power point tracking of solar PV systems in partial shading condition
Autorzy:
Bentata, Khadidja
Mohammedi, Ahmed
Benslimane, Tarak
Powiązania:
https://bibliotekanauki.pl/articles/1845531.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
photovoltaic system
maximum power point tracking
partial shading
cuckoo search algorithm
Opis:
The solar photovoltaic output power fluctuates according to solar irradiation, temperature, and load impedance variations. Due to the operating point fluctuations, extracting maximum power from the PV generator, already having a low power conversion ratio, becomes very complicated. To reach a maximum power operating point, a maximum power point tracking technique (MPPT) should be used. Under partial shading condition, the nonlinear PV output power curve contains multiple maximum power points with only one global maximum power point (GMPP). Consequently, identifying this global maximum power point is a difficult task and one of the biggest challenges of partially shaded PV systems. The conventional MPPT techniques can easily be trapped in a local maximum instead of detecting the global one. The artificial neural network techniques used to track the GMPP have a major drawback of using huge amount of data covering all operating points of PV system, including different uniform and non-uniform irradiance cases, different temperatures and load impedances. The biological intelligence techniques used to track GMPP, such as grey wolf algorithm and cuckoo search algorithm (CSA), have two main drawbacks; to be trapped in a local MPP if they have not been well tuned and the precision-transient tracking time complex paradox. To deal with these drawbacks, a Distributive Cuckoo Search Algorithm (DCSA) is developed, in this paper, as GMPP tracking technique. Simulation results of the system for different partial shading patterns demonstrated the high precision and rapidity, besides the good reliability of the proposed DCSA- GMPPT technique, compared to the conventional CSA-GMPPT.
Źródło:
Archives of Control Sciences; 2021, 31, 3; 495-526
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geometry of fibers with varying topology
Geometria włókien ze zmienną topologią
Autorzy:
Hast, A.
Powiązania:
https://bibliotekanauki.pl/articles/118882.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Geometrii i Grafiki Inżynierskiej
Tematy:
anisotropic shading
illumination model
flat topology
cieniowanie anizotropowe
model iluminacji
topologia płaska
Opis:
Anisotropic shading techniques can be used for materials like hair and silk. Such materials have a surface consisting of very small fibers having a main direction. Geometrically each fiber can be viewed as a cylinder. Poulin and Fournier proposed an illumination model for such materials using a flat topology only. In the paper a model using a varying topology is described. The varying topology is a more correct model and visible differences are clearly apparent. In the paper the necessary equations for computing the geometry of the fibers are presented
Anizotropowe techniki cieniowania barw przedmiotów opierają się na materiałach takich jak włosy lub jedwab. Materiały te mają powierzchnię składającą się z bardzo cienkich włókien mających kierunek styczny do powierzchni. Geometrycznie każde włókno może być wizualizowane jako walec. Paulin i Fournier proponują model iluminacji używając jedynie płaskiej topologii. W pracy opisano model z wykorzystaniem zmiennej topologii i uzyskano o wiele bardziej poprawne przedstawienie obiektu. Wyprowadzono wzory niezbędne do obliczeń geometrii włókien.
Źródło:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics; 2006, 16; 5-10
1644-9363
Pojawia się w:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cienie i cieniowanie w grafice komputerowej
Shades and shadows in computer graphics
Autorzy:
Helenowska-Peschke, M.
Powiązania:
https://bibliotekanauki.pl/articles/119001.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Geometrii i Grafiki Inżynierskiej
Tematy:
grafika komputerowa
cieniowanie
cienie
wizualizacja architektoniczna
computer graphics
shading
shadows
architectural visualization
Opis:
Współcześnie grafika komputerowa umożliwia tworzenie światłocieni z powodzeniem symulujących efekty oświetlenia obiektów występujące w świecie rzeczywistym. W artykule krótko przedstawiono podstawowe algorytmy wyznaczania cieni oraz możliwości kreowania cieni w 3D Studio – popularnym programie typu CAD.
Contemporary computer graphics has an ability to create shade and shadows which successfully stimulate light effects in real world. In the paper basic algorithms for creating shade and shadows are shortly presented as well as shade and shadow options in 3D Studio – the popular CAD program.
Źródło:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics; 2003, 13; 19-23
1644-9363
Pojawia się w:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics
Dostawca treści:
Biblioteka Nauki
Artykuł
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