Implementation of a modified P&O-MPPT algorithm adapted for varying solar radiation conditions

2016 ◽  
Vol 99 (3) ◽  
pp. 839-846 ◽  
Author(s):  
Abdelhakim Belkaid ◽  
Ilhami Colak ◽  
Korhan Kayisli
Keyword(s):  
Solar Radiation ◽  
Radiation Conditions

scholarly journals Assessment of Artificial Neural Networks for Hourly Solar Radiation Prediction

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Tamer Khatib ◽  
Azah Mohamed ◽  
K. Sopian ◽  
M. Mahmoud
Keyword(s):  
Neural Networks ◽  
Solar Radiation ◽  
Mean Bias Error ◽  
Percentage Error ◽  
Bias Error ◽  
Climate Conditions ◽  
The Neural Networks ◽  
Artificial Neural ◽  
Artificial Neural Network Ann ◽  
Radiation Conditions

This paper presents an assessment for the artificial neural network (ANN) based approach for hourly solar radiation prediction. The Four ANNs topologies were used including a generalized (GRNN), a feed-forward backpropagation (FFNN), a cascade-forward backpropagation (CFNN), and an Elman backpropagation (ELMNN). The three statistical values used to evaluate the efficacy of the neural networks were mean absolute percentage error (MAPE), mean bias error (MBE) and root mean square error (RMSE). Prediction results show that the GRNN exceeds the other proposed methods. The average values of the MAPE, MBE and RMSE using GRNN were 4.9%, 0.29% and 5.75%, respectively. FFNN and CFNN efficacies were acceptable in general, but their predictive value was degraded in poor solar radiation conditions. The average values of the MAPE, MBE and RMSE using the FFNN were 23%, −.09% and 21.9%, respectively, while the average values of the MAPE, MBE and RMSE using CFNN were 22.5%, −19.15% and 21.9%, respectively. ELMNN fared the worst among the proposed methods in predicting hourly solar radiation with average MABE, MBE and RMSE values of 34.5%, −11.1% and 34.35%. The use of the GRNN to predict solar radiation in all climate conditions yielded results that were highly accurate and efficient.

scholarly journals Modeling Approach for Determining Equivalent Optical Constants of Plastic Shading Nets under Solar Radiation Conditions

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
A. M. Abdel-Ghany ◽  
I. M. Al-Helal
Keyword(s):  
Solar Radiation ◽  
Optical Constants ◽  
Present Model ◽  
Incident Angle ◽  
Radiative Properties ◽  
Beam Radiation ◽  
Extinction Coefficients ◽  
Average Value ◽  
Texture Structure ◽  
Radiation Conditions

The radiative properties of several plastic shading nets were measured under natural solar radiation conditions. We found that the plastic nets behave as homogeneous translucent materials (e.g., plastic film, plastic sheets, and glass). Based on this behavior, we suggest that it is possible to treat plastic nets as translucent materials and to characterize them with equivalent optical constants (i.e., equivalent refractive indexes,neq, and equivalent extinction coefficients,σeq). Here a physical model to determineneqandσeqof plastic nets was described in analogy to homogeneous translucent materials. We examined three groups of nets based on their color (black, black-green, and beige). Each group consisted of nets with four or five different porosities. Nets of each group had almost the same texture structure. For each group, we derived an equation forneqas a function of the net porosity and determined an average value forσeq. Once values ofneqandσeqwere determined, the solar radiative properties of a net could then be calculated fromneqandσeqfor any incident angle of solar beam radiation without the need of measurements. The present model was validated by comparing the calculated with the measured radiative properties of three nets at different incident angle of solar beam radiation. The calculated radiative properties reasonably agreed with measured values.

scholarly journals Structure of radiation balance in diverse types of relief

2015 ◽  
Vol 47 (4) ◽  
pp. 343-354 ◽  
Author(s):  
Zbigniew Caputa ◽  
Jakub Wojkowski
Keyword(s):  
Land Use ◽  
Solar Radiation ◽  
Small Area ◽  
Global Solar Radiation ◽  
Wave Radiation ◽  
Radiation Balance ◽  
Full Spectrum ◽  
Plant Groups ◽  
One Year ◽  
Radiation Conditions

Abstract Structure of radiation balance in diverse types of relief. The article presents the results of research on the structure of radiation balance in the full spectrum in diverse types of relief. The study was carried out on the Kraków-Częstochowa Upland (Poland). The varying terrain, its forms, expositions and slopes, large denivelations, and the varying land cover and land use make this small area very diverse as far as radiation conditions are concerned. On the basis of an actinometrical study the structure of radiation balance was assessed in two distinct morphologic terrain forms: the bottom of the valley and the plateau. It was proved that the global solar radiation (K↓) reaching the bottom of the valley in one year was on average 15% lower than the solar energy reaching the plateau. The all wave radiation balance (Q*) at the bottom of the valley was 16% less than on the plateau. The result of complex radiation conditions in the diversified relief was the occurrence of a mosaic of plant groups with distinct requirements.

Analysis of The Performance of A PV/PCM System in Variable Solar Radiation Conditions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Carlos Armenta-Deu
Keyword(s):  
Steady State ◽  
Melting Point ◽  
Solar Radiation ◽  
Transient State ◽  
Good Method ◽  
Day Length ◽  
System Response ◽  
Time Interval ◽  
Steady State Temperature ◽  
Radiation Conditions

This paper studies the performance of a PV/PCM system operating at variable solar radiation conditions. The system has been tested for six different solar radiation levels, from 250 W/m2 to 950 W/m2 determining the steady-state temperature for every case. An algorithm has been developed to predict the steady-state temperature. This prediction has produced values within 97% accuracy of experimental data. A reduction of temperature up to 18.9ºC has been achieved. An algorithm has been developed to correlate reduction in temperature with solar radiation levels. This algorithm can be combined with the classical expression for the PV panel efficiency resulting in a good method for determining the increase of the efficiency. Additionally, the system has been tested for continuous solar radiation evolution, analyzing the system response under the transient state. The procedure has been conducted for the former six solar radiation levels considering the solar radiation evolves linearly from one value to another during a time interval. The simulation has been tested against outdoor solar radiation with an accuracy higher than 98%. The predicted value of the PCM Temperature at the end of the day as shown matches the melting point of the PCM used in the experiment (55ºC), which has been verified experimentally. Besides, the transient state analysis has given the temperature evolution of the PCM at every interval, resulting in a very good match with experimental tests. The analysis of the transient state that the system reaches the melting point at 1/3 of the solar day length, maintaining the phase change state for the rest of the day. This is in good agreement with the experimental observation.

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