scholarly journals UV Visual Spectral Response of Transformer Oil Under The Impact of Thermal and Electrical Stress

2021 ◽  
Author(s):  
Murugesan Srinivasan ◽  
Sumarkumar Burnwal
Keyword(s):  
Spectral Response ◽  
Transformer Oil ◽  
Electrical Stress ◽  
The Impact

scholarly journals Influence of the weights in IHS and Brovey methods for pan-sharpening WorldView-3 satellite images

2017 ◽  
Vol 6 (3) ◽  
pp. 71 ◽  
Author(s):  
Claudio Parente ◽  
Massimiliano Pepe
Keyword(s):  
Satellite Images ◽  
Urban Landscape ◽  
Spectral Response ◽  
Rural Landscape ◽  
Spectral Radiance ◽  
Data Sets ◽  
Data Set ◽  
Inertial Moment ◽  
The Impact

The purpose of this paper is to investigate the impact of weights in pan-sharpening methods applied to satellite images. Indeed, different data sets of weights have been considered and compared in the IHS and Brovey methods. The first dataset contains the same weight for each band while the second takes in account the weighs obtained by spectral radiance response; these two data sets are most common in pan-sharpening application. The third data set is resulting by a new method. It consists to compute the inertial moment of first order of each band taking in account the spectral response. For testing the impact of the weights of the different data sets, WorlView-3 satellite images have been considered. In particular, two different scenes (the first in urban landscape, the latter in rural landscape) have been investigated. The quality of pan-sharpened images has been analysed by three different quality indexes: Root mean square error (RMSE), Relative average spectral error (RASE) and Erreur Relative Global Adimensionnelle de Synthèse (ERGAS).

Mitigating the impact of aging byproducts in transformer oil using TiO2 nanofillers

2017 ◽  
Vol 24 (6) ◽  
pp. 3471-3480 ◽  
Author(s):  
Manal M. Emara ◽  
Diaa-Eldin A. Mansour ◽  
Ahmed M. Azmy
Keyword(s):  
Transformer Oil ◽  
The Impact

scholarly journals Surface Dust and Aerosol Effects on the Performance of Grid-Connected Photovoltaic Systems

2020 ◽  
Vol 12 (2) ◽  
pp. 569 ◽  
Author(s):  
Elias Roumpakias ◽  
Tassos Stamatelos
Keyword(s):  
Spectral Response ◽  
Reference Value ◽  
The Other ◽  
Pv System ◽  
Ambient Aerosols ◽  
Ambient Aerosol ◽  
Aerosol Mass Concentration ◽  
Other Hand ◽  
The Impact ◽  
Dust Accumulation

A large number of grid-connected Photovoltaic parks of different scales have been operating worldwide for more than two decades. Systems’ performance varies with time, and an important factor that influences PV performance is dust and ambient aerosols. Dust accumulation has significant effects depending the region, and—on the other hand—understanding the role of absorption or scattering in particular wavelengths from aerosols is a challenging task. This paper focuses on performance analysis of a grid-connected PV system in Central Greece, aiming to study these effects. The methodology of analysis follows three directions, namely, PR computations, use of mathematical model’s prediction as reference value, and normalized efficiency calculation. These metrics are correlated with the levels of dust accumulation on PV panels’ surfaces and the ambient aerosol mass concentration. The results show that only heavily soiled surfaces have significant impact on PV performance and, particularly, a decrease of 5.6%. On the other hand, light or medium soiling have negligible impact on PV performance. On the other hand, the impact of ambient aerosol concentration levels on PV efficiency is more complex and requires further study. Aerosol scattering of different wavelengths can possibly affect PV efficiency, however, this fact may be related to the specific spectral response of PV cells.

scholarly journals Spectral Irradiance Influence on Solar Cells Efficiency

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5017
Author(s):  
David Leitão ◽  
João Paulo N. Torres ◽  
João F. P. Fernandes
Keyword(s):  
Near Infrared ◽  
Spectral Response ◽  
Experimental Tests ◽  
Optical Filters ◽  
Spectral Irradiance ◽  
Copper Indium ◽  
Input Variables ◽  
Relative Errors ◽  
The Impact ◽  
High Pass

This paper investigates the influence of the spectral irradiance variation and the spectral response (SR) on the production of energy by photovoltaic cells. To determine the impact of SR and spectral irradiance on m-Si and perovskite cells, experimental tests were conducted outdoors, used optical filters to select different zones of the spectrum. For the computational simulations of the different photovoltaic modules, when subjected to a certain spectral irradiance, a model with spectral factor (SF) was implemented. The SF model accurately simulated the experiments performed for the high-pass filters. The highest relative errors for certain irradiation bands occurred due to the input variables used in the model, which did not fully describe the reality of the experiments performed. The effect of the SR and the spectral irradiance for each of them were observed through the simulations for the m-Si, a-Si, CdTe, and copper indium selenide (CIS) modules. The CIS technology presented a better overall result in the near infrared zone, producing about half of the energy produced by the CdTe technology in the visible zone. The SF, spectral incompatibility factor (MM), and spectral effective responsivity (SEF) parameters were verified to be important for studying the photovoltaic energy production.

The On-Line Monitoring of the Winding Deformation of Transformer Based on the Improved Ultrasonic Ranging Method

2014 ◽  
Vol 672-674 ◽  
pp. 1159-1162 ◽  
Author(s):  
Wei Jia Liu ◽  
Xin Wang ◽  
Yi Hui Zheng ◽  
Li Xue Li ◽  
Yong Bo Lang ◽  
...  
Keyword(s):  
Transformer Oil ◽  
Practical Significance ◽  
Test Results ◽  
Signal Attenuation ◽  
Ultrasonic Ranging ◽  
Transformer Winding ◽  
On Line ◽  
Working Principle ◽  
Winding Deformation ◽  
The Impact

The assessment of the winding deformation of transformer has a certain practical significance. In this paper, an Improved Ultrasonic Ranging (IUR) method is proposed to assess the winding deformation of transformer. Firstly, the basic principle of winding deformation detection using ultrasonic and the working principle of detection device are discussed. Secondly, the impact of the factors such as transformer oil temperature and echo signal attenuation on the test results is analyzed. Then, a new IUR method is composed, which can realize the on-line monitoring of transformer winding deformation. Finally, an assessment equipment of transformer winding deformation based on the online monitoring is developed, and a prototype is used to test the transformer mode, proving that this method is feasible.

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