scholarly journals Performance and Design Optimization of Two-Mirror Composite Concentrating PV Systems

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2875
Author(s):  
Guihua Li ◽  
Yamei Yu ◽  
Runsheng Tang
Keyword(s):  
Tilt Angle ◽  
Three Dimensional ◽  
Acceptance Angle ◽  
Pv System ◽  
Pv Systems ◽  
Calculation Results ◽  
The One ◽  
A Site ◽  
Plate Absorber ◽  
East West

The reflectors of a linear solar concentrator investigated in this work consisted of two plane mirrors (2MCC), and they were designed in such a way that made all radiation within the acceptance angle (θa) arrive on flat-plate absorber, after less than two reflections. To investigate the performance of an east–west aligned 2MCC-based photovoltaic (PV) system (2MCPV), a mathematical procedure was suggested based on the three-dimensional radiation transfer and was validated by the ray-tracing analysis. Analysis indicated that the performance of 2MCPV was dependent on the geometry of 2MCC, the reflectivity of mirrors (ρ), and solar resources in a site, thus, given θa, an optimal geometry of 2MCC for maximizing the annual collectible radiation (ACR) and annual electricity generation (AEG) of 2MCPV in a site could be respectively found through iterative calculations. Calculation results showed that when the ρ was high, the optimal design of 2MCC for maximizing its geometric concentration (Cg) could be utilized for maximizing the ACR and AEG of 2MCPV. As compared to similar compound parabolic concentrator (CPC)-based PV systems, the 2MCPV with the tilt-angle of the aperture yearly fixed (1T-2MCPV), annually generated more electricity when the ρ was high; and the one with the tilt-angle adjusted yearly four times at three tilts (3T-2MCPV), performed better when θa < 25° and ρ > 0.7, even in sites with poor solar resources.

scholarly journals A Novel Current Sensor less MPPT based Approach for PV Applications Using PSO Technique

2021 ◽  
Vol 2070 (1) ◽  
pp. 012123
Author(s):  
Vinay Kumar ◽  
T Naveen Kumar ◽  
K T Prajwal
Keyword(s):  
Solar Energy ◽  
Renewable Energy Sources ◽  
Maximum Power ◽  
Current Sensor ◽  
Pv System ◽  
Pv Systems ◽  
Power Resources ◽  
Point Tracking ◽  
Power Point ◽  
The One

Abstract As an increased demand in power resources and to reduce global warming, Renewable Energy Sources (RES) are preferred over the conventional sources. Among various available RES, solar energy is the effective and efficient one. The solar energy is also clean and free energy. The use of Maximum Power Point Tracking (MPPT) is the one of the techniques to get maximized output power from the Photo Voltaic (PV) system. The proposed method uses a voltage sensor by eliminating the need of current sensor based on selected technique using Partial Swarm Optimization (PSO) technique interfaced with DC-DC boost converter. PSO technique is one of the methods which has high conflux speed, to precisely track the maximum power. The result of the planned methodology is studied with the assistance of an acceptable simulation applied in MATLAB/Simulink setting for experiment to valid of microcontroller which is employed. The result obtained from the simulations studies showed that current sensor less methodology using PSO technique can extract the maximize power from PV systems.

Analysis of the Containment Thermal-Hydraulic Behavior of a Small Reactor During Loss of Coolant Accident

2017 ◽  
Author(s):  
Qian Lin ◽  
Weizhong Zhang
Keyword(s):  
Cooling System ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Loss Of Coolant Accident ◽  
Lumped Parameter ◽  
Loss Of Coolant ◽  
Calculation Results ◽  
The One

The containment thermal hydraulics of a small reactor during loss of coolant accident (LOCA) is studied by a lumped parameter one-dimensional model and a three-dimensional model. The capability of a kind of heat exchanger type passive containment cooling system (PCCS) is analyzed by the one-dimensional model. The calculation results show that, the decay heat can be removed and the containment pressure can be decreased by the proposed PCCS. The steam and non-condensable gas (the air) distribution in the containment is investigated, the mixing and stratification behaviors are analyzed for several different cases, in which the PCCS and condenser are located at higher, base or lower position. The sensitivity analysis of the PCCS elevation shows that, in despite of the different gas stratification, the containment pressures are nearly the same. Similar conclusions can be obtained by the one-dimensional model and three-dimensional model. The preliminary results may indicate that, the designed PCCS and condenser can be located at a lower part, which will be benefit for the economy of the small reactor or meet other requirements.

scholarly journals A Software Tool for Optimal Sizing of PV Systems in Malaysia

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Tamer Khatib ◽  
Azah Mohamed ◽  
K. Sopian
Keyword(s):  
Solar Energy ◽  
Tilt Angle ◽  
Software Tool ◽  
Diesel Generator ◽  
Pv System ◽  
Generator System ◽  
Optimal Sizing ◽  
Pv Systems ◽  
Artificial Neural Network Ann ◽  
User Friendly

This paper presents a MATLAB based user friendly software tool called as PV.MY for optimal sizing of photovoltaic (PV) systems. The software has the capabilities of predicting the metrological variables such as solar energy, ambient temperature and wind speed using artificial neural network (ANN), optimizes the PV module/ array tilt angle, optimizes the inverter size and calculate optimal capacities of PV array, battery, wind turbine and diesel generator in hybrid PV systems. The ANN based model for metrological prediction uses four meteorological variables, namely, sun shine ratio, day number and location coordinates. As for PV system sizing, iterative methods are used for determining the optimal sizing of three types of PV systems, which are standalone PV system, hybrid PV/wind system and hybrid PV/diesel generator system. The loss of load probability (LLP) technique is used for optimization in which the energy sources capacities are the variables to be optimized considering very low LLP. As for determining the optimal PV panels tilt angle and inverter size, the Liu and Jordan model for solar energy incident on a tilt surface is used in optimizing the monthly tilt angle, while a model for inverter efficiency curve is used in the optimization of inverter size.

Optical Performance Comparison of Six ACPCs for Concentrating Radiation on All-Glass Evacuated Solar Tubes

2015 ◽  
Vol 1092-1093 ◽  
pp. 52-58 ◽  
Author(s):  
Rui Hua Xu ◽  
Qi Chao Zhang ◽  
Run Sheng Tang
Keyword(s):  
Ray Tracing ◽  
Concentration Factor ◽  
Performance Comparison ◽  
Optical Performance ◽  
Acceptance Angle ◽  
Direct Sunlight ◽  
Optical Efficiency ◽  
The One ◽  
East West ◽  
Tracing Method

In this work, six asymmetric compound parabolic concentrators (ACPC) were designed for concentrating radiation on all-glass evacuated solar tubes (EST). The ACPCs are required to be horizontally oriented in the east-west direction and to collect direct sunlight for at least 6 hrs in any day of a year. The angular dependence of optical efficiency of six ACPCs, identical in the height of both reflectors after the higher reflector being truncated, was investigated by ray-tracing method, and the annual radiation on EST concentrated by ACPCs was estimated based on solar geometry and monthly horizontally radiation. Results shows that the ACPC designed based on “hat shaped” virtual absorber with a V-groove at the bottom of reflectors is the best in terms of the optical efficiency averaged over the acceptance angle, followed by the one designed based on “hat-shaped” absorber without a V-groove at the bottom, and the one designed based on the cover tube of EST is the worst. However, from the point of annual radiation on EST, the ACPC designed based on the cover tube is the best solution, followed by the one designed based on “ice-cream shaped” absorber and the one designed based on “hat shaped” absorber is the worst due to the smallest geometric concentration factor.

scholarly journals Energy Yield of Tracking PV Systems in Jordan

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
A. Al Tarabsheh ◽  
I. Etier ◽  
A. Nimrat
Keyword(s):  
Tracking System ◽  
Global Radiation ◽  
System Optimization ◽  
Energy Yield ◽  
Pv System ◽  
Pv Systems ◽  
Pv Modules ◽  
Inclination Angles ◽  
Simulation Results ◽  
The One

This paper analyzes the energy yield of photovoltaic (PV) modules mounted on fixed tilt, one-axis, and two-axis tracking system towards maximizing the annual energy production. The performance evaluation of the proposed design of the tracking systems is carried via simulating the global radiation averages using METEONORM software and depicting the simulation results in figures using MATLAB software. The one-axis system is simulated by either fixing the azimuth angle while optimizing the inclination angles or fixing the inclination angle while optimizing the azimuth angles; simulation results show an increase in energy yield of 5.87% and 20.12% compared to that of fixed tilt system, respectively. In the two-axis system, optimization of both azimuth and inclination angles is carried out simultaneously which resulted in 30.82% improvement in energy yield. Therefore, 30% improvement in energy yield is directly reflected as saving in PV system cost due to reduction of the PV modules surface area.

scholarly journals Performance and Design Optimization of a One-Axis Multiple Positions Sun-Tracked V-trough for Photovoltaic Applications

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1141 ◽  
Author(s):  
Guihua Li ◽  
Jingjing Tang ◽  
Runsheng Tang
Keyword(s):  
Power Output ◽  
Three Dimensional ◽  
Diffuse Radiation ◽  
Incident Radiation ◽  
Opening Angle ◽  
Photovoltaic Module ◽  
Water Pumping ◽  
Photovoltaic Applications ◽  
Calculation Results ◽  
A Site

In this article, the performance of an inclined north-south axis (INSA) multiple positions sun-tracked V-trough with restricted reflections for photovoltaic applications (MP-VPVs) is investigated theoretically based on the imaging principle of mirrors, solar geometry, vector algebra and three-dimensional radiation transfer. For such a V-trough photovoltaic module, all incident radiation within the angle θ a arrives on solar cells after less than k reflections, and the azimuth angle of V-trough is daily adjusted M times about INSA to ensure incident solar rays always within θ a in a day. Calculations and analysis show that two-dimensional sky diffuse radiation can’t reasonably estimate sky diffuse radiation collected by fixed inclined north-south V-trough, but can for MP-VPVs. Results indicate that, the annual power output (Pa) of MP-VPVs in a site is sensitive to the geometry of V-trough and wall reflectivity (ρ), hence given M, k and ρ, a set of optimal θ a and φ , the opening angle of V-trough, for maximizing Pa can be found. Calculation results show that the optimal θ a is about 21°, 13.5° and 10° for 3P-, 5P- and 7P-VPV-k/ θ a (k = 1 and 2), respectively, and the optimal φ for maximizing Pa is about 30° for k = 1 and 21° for k = 2when ρ > 0.8. As compared to similar fixed south-facing PV panels, the increase of annual electricity from MP-VPVs is even larger than the geometric concentration of V-trough for ρ > 0.8 in sites with abundant solar resources, thus attractive for water pumping due to stable power output in a day.

Optical Losses through Gaps of CPCs with One-Sided Flat Absorber

2015 ◽  
Vol 737 ◽  
pp. 46-52
Author(s):  
Feng Tang ◽  
Run Sheng Tang
Keyword(s):  
Tilt Angle ◽  
Optical Loss ◽  
Radiation Loss ◽  
Optical Losses ◽  
Multiple Reflections ◽  
Acceptance Angle ◽  
Direct Radiation ◽  
Direct Irradiation ◽  
Solar Resource ◽  
East West

In this work, the angular dependence of optical losses through gaps, constructed by truncating reflectors near the absorbers, of CPCs with one-sided flat absorber was presented, and the annul radiation loss through gaps of east-west aligned CPCs is theoretically investigated. Results show that the optical losses are mainly resulted from direct radiation loss through gaps due to direct irradiation on gaps, and the loss of radiation that arrive on gaps from reflectors after multiple reflections is considerable small and can be neglected in solar calculations especially for truncated CPCs. Results also show that the annual direct radiation loss is dependent on geometric parameters of CPCs but seems independent on solar resource in sites where CPCs are used, and the annual radiation loss of full CPCs oriented in east-west direction with the tilt-angle of aperture being yearly fixed is almost identical to average optical loss of the CPC over its acceptance angle.

Suitability Analysis of Solar Tracking PV System in the Airport Based on Glare Assessment

2021 ◽  
Vol 18 (3) ◽  
pp. 9061-9070
Author(s):  
S. Sreenath ◽  
K. Sudhakar ◽  
A.F. Yusop
Keyword(s):  
Safety Issue ◽  
Solar Pv ◽  
Suitability Analysis ◽  
Pv System ◽  
Pv Systems ◽  
Theoretical Support ◽  
Solar Tracking ◽  
Harmful Emissions ◽  
Solar Pv System ◽  
The One

Due to the concerns with harmful emissions, airports have a great interest in solar photovoltaic technology. On the one hand, the vacant land areas in the airport can house solar PV arrays. On the other hand, there is an aviation safety issue due to the reflections from the solar PV arrays. This paper aims to perform a glare analysis of a conceptual solar PV array for three different solar tracking techniques. This suitability analysis is carried out for fixed-tilt, single-axis and dual-axis tracking techniques using ForgeSolar software. It is observed that a single-axis tracking solar PV system is a suitable tracking technique for the selected site. This can be attributed to zero minutes of glare duration and the highest value of energy generation. In addition to compliance with the FAA’s solar glare policy, the single-axis tracking solar PV system will generate 40 % more electricity than a fixed-tilt solar PV system. Unlike previously reported studies, the results of this study strengthen the theoretical support for tracking solar PV systems in airport locations. The findings provided in this study will be beneficial to energy professionals and serve as reference material for tracking solar PV in airports.

Methods for three-dimensional reconstruction of cellular components within a thick section

1986 ◽  
Vol 44 ◽  
pp. 18-21
Author(s):  
J. Frank ◽  
B. F. McEwen ◽  
M. Radermacher ◽  
C. L. Rieder
Keyword(s):  
Tilt Angle ◽  
Tomographic Reconstruction ◽  
3D Structure ◽  
Three Dimensional ◽  
Thick Section ◽  
Three Dimensional Reconstruction ◽  
Axis Ratio ◽  
Dimensional Reconstruction ◽  
Cellular Components

The tomographic reconstruction from multiple projections of cellular components, within a thick section, offers a way of visualizing and quantifying their three-dimensional (3D) structure. However, asymmetric objects require as many views from the widest tilt range as possible; otherwise the reconstruction may be uninterpretable. Even if not for geometric obstructions, the increasing pathway of electrons, as the tilt angle is increased, poses the ultimate upper limitation to the projection range. With the maximum tilt angle being fixed, the only way to improve the faithfulness of the reconstruction is by changing the mode of the tilting from single-axis to conical; a point within the object projected with a tilt angle of 60° and a full 360° azimuthal range is then reconstructed as a slightly elliptic (axis ratio 1.2 : 1) sphere.

Diffraction contrast of dislocations in icosahedral quasicrystals

1990 ◽  
Vol 48 (4) ◽  
pp. 454-455
Author(s):  
K. Urban ◽  
Z. Zhang ◽  
M. Wollgarten ◽  
D. Gratias
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Complete Characterization ◽  
Extinction Condition ◽  
Burgers Vector ◽  
Diffraction Contrast ◽  
Lattice Geometry ◽  
Reference Space ◽  
Icosahedral Quasicrystals ◽  
The One

Recently dislocations have been observed by electron microscopy in the icosahedral quasicrystalline (IQ) phase of Al65Cu20Fe15. These dislocations exhibit diffraction contrast similar to that known for dislocations in conventional crystals. The contrast becomes extinct for certain diffraction vectors g. In the following the basis of electron diffraction contrast of dislocations in the IQ phase is described. Taking account of the six-dimensional nature of the Burgers vector a “strong” and a “weak” extinction condition are found.Dislocations in quasicrystals canot be described on the basis of simple shear or insertion of a lattice plane only. In order to achieve a complete characterization of these dislocations it is advantageous to make use of the one to one correspondence of the lattice geometry in our three-dimensional space (R3) and that in the six-dimensional reference space (R6) where full periodicity is recovered . Therefore the contrast extinction condition has to be written as gpbp + gobo = 0 (1). The diffraction vector g and the Burgers vector b decompose into two vectors gp, bp and go, bo in, respectively, the physical and the orthogonal three-dimensional sub-spaces of R6.

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