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Harmonic analysis of common-mode voltage in quasi-z-source inverters
, Article 2019 IEEE International Conference on Industrial Technology, ICIT 2019, 13 February 2019 through 15 February 2019 ; Volume 2019-February , 2019 , Pages 1778-1783 ; 9781538663769 (ISBN) ; Yaghoubi, M ; Davoodi, A ; Ouni, S ; Zolghadri, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In a transformerless grid-connected photovoltaic system, many issues arise from the leakage current flow into the ground, as EMI problems. The leakage current is originated from the common-mode voltage fluctuations. In this paper, the common-mode voltage harmonics in a three-phase quasi-Z-source inverter are analyzed using Fourier transform and a closed-loop formulation is presented for the harmonics value. The shoot-through mode in a quasi-Z-source inverter causes extra fluctuations in the common-mode voltage comparing to a classic inverter. The proposed harmonic analysis method provides a systematic way to figure out how shoot-through mode and also other parameters affect the common-mode...
Numerical analysis of photovoltaic solar panel cooling by a flat plate closed-loop pulsating heat pipe
, Article Solar Energy ; Volume 206 , 2020 , Pages 455-463 ; Alhuyi Nazari, M ; Ghasempour, R ; Shafii, M. B ; Akbarzadeh, A. A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Photovoltaic (PV) panels provide a suitable way for the direct conversion of solar energy into electricity. The electrical output and efficiency of PV modules are dependent on working temperature. The present study contributes to investigate the efficiency of utilizing a flat plate closed-loop pulsating heat pipe (CLPHP) to cool down a PV panel in both thermal and economic aspects. Accordingly, a numerical investigation is employed to obtain the surface temperature and electrical gain of the PV panel through four scenarios, including natural cooling without additional equipment, CLPHP-based passive cooling, CLPHP-based active cooling, and a conventional flat plate cooling methods. The...
Multi-input high step-up inverter with softswitching capability, applicable in photovoltaic systems
, Article IET Power Electronics ; Volume 13, Issue 1 , 2020 , Pages 133-143 ; Tarzamni, H ; Tahami, F ; Khoun Jahan, H ; Bannae Sharifian, M. B ; Sharif University of Technology
Institution of Engineering and Technology
2020
Abstract
In this study, a new multi-input high step-up inverter, based on isolated soft-switching DC-DC converter blocks is proposed. Each of these blocks can provide zero-voltage and zero-current switching for its semiconductors, which improve power efficiency. The interesting feature of this DC-DC converter is using bidirectional switches to generate both positive and negative output voltage levels in each DC-DC block with an appropriate control scheme. Each DC-DC converter operates by simple pulse width modulation control through fixed frequency and has two degrees of freedom, which provide the capability of output voltage regulation or maximum power point tracking. The proposed inverter consists...
Enhanced performance of planar perovskite solar cells using TiO2/SnO2 and TiO2/WO3 bilayer structures: Roles of the interfacial layers
, Article Solar Energy ; Volume 208 , 2020 , Pages 697-707 ; Ranjbar, M ; Kermanpur, A ; Taghavinia, N ; Minbashi, M ; Forouzandeh, M ; Ebadi, F ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In planar perovskite solar cells (PSCs), engineering the extraction and recombination of electron–hole pairs by modification of the electron transport layer (ETL)/perovskite interface is very vital for obtaining high performance. The main idea here is to improve properties of the TiO2/perovskite interface by inserting an ultra-thin layer (UTL) of WO3 or SnO2 with the thickness of less than 10 nm by RF magnetron sputtering method. The structural and electrical characteristics of the samples were tested by XRD, AFM, FE-SEM, Mott-Schottky analysis, UV–Vis spectroscopy, J-V characterization and electrochemical impedance spectroscopy (EIS). It was found that the bilayer structured ETLs exhibit...
Suppressing recombination in perovskite solar cells via surface engineering of TiO2 ETL
, Article Solar Energy ; Volume 197 , 2020 , Pages 50-57 ; Tavakoli, M. M ; Wolska Pietkiewicz, M ; Jędrzejewska, M ; Trivedi, S ; Kumar, M ; Zakeeruddin, S. M ; Lewiński, J ; Graetzel, M ; Yadav, P ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Hybrid perovskite solar cells (PSCs) have gained significant attention owing to their excellent physicochemical and photovoltaic properties. PSCs typically consist of a perovskite light absorber sandwiched between two carrier selective layers optimized with respect to optimal band alignment and low interfacial recombination. The quality of the perovskite layer and interfaces play major roles in the fabrication of high-performance PSCs. In the present work, we systematically investigate the planar structure PSCs based on TiO2 and TiO2/ZnO electron transport layers (ETLs), which provide deeper insight into the charge recombination and accumulation mechanisms. We show that the double-layer...
On the performance of inclined rooftop solar chimney integrated with photovoltaic module and phase change material: A numerical study
, Article Solar Energy ; Volume 211 , 2020 , Pages 1159-1169 ; Ashouri, M ; Hakkaki Fard, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In an attempt to prolong the performance of the conventional Solar Chimney (SC) and enhance its efficiency, this contribution presents a kind of novel compound SC with the Photovoltaic (PV) module and Phase Change Material (PCM) called the SC-PV-PCM system. Using PCM not only improves the PV module performance but also extends the productive period of the SC. A three-dimensional quasi-steady computational fluid dynamics (CFD) model of the proposed system is developed. The developed model is used to investigate the effect of using PCMs with different melting points on the performance of the proposed system. It is demonstrated that the RT-50 provides superior performance among the studied...
A numerical study on a photovoltaic thermal system integrated with a thermoelectric generator module
, Article Renewable Energy ; Volume 153 , 2020 , Pages 1261-1271 ; Parcheforosh, A ; Hakkaki Fard, A ; Amadeh, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this work, a three-dimensional numerical model is developed to investigate the performance of a photovoltaic thermal system integrated with a thermoelectric generator module (PVT/TE). Furthermore, the effects of various operating parameters such as solar radiation, coolant mass flow rate, and inlet and ambient temperatures on the performance of both the PVT and PVT/TE systems are investigated and compared. Based on the obtained results, the electrical efficiency of the PVT/TE system, when exposed to solar radiation of 600 and 1000 W/m2, is 6.23% and 10.41% higher than that of the PVT system, respectively. Besides, the electrical efficiency of the PVT and PVT/TE by increasing the inlet...
Efficiency improvement of solar stills through wettability alteration of the condensation surface: An experimental study
, Article Applied Energy ; Volume 268 , 2020 ; Soltani Goharrizi, A ; Ayatollahi, S ; Feilizadeh, M ; Dashti, H ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The condensation process is of great importance in many heat transfer devices in which a large amount of energy must be transferred. Furthermore, condensation is a crucial part of energy conversion and affects the energy efficiency of thermal desalination plants and solar stills. During the condensation process in solar stills, an essential part of the energy is transferred through the condensation surface to produce fresh water. Therefore, the condensation surface plays a significant role in the working efficiency of solar stills. The wettability of the condensation surface influences the condensation mechanism, which, in turn, affects the efficiency of solar stills. This study aims to...
Optimization of a novel photovoltaic thermal module in series with a solar collector using Taguchi based grey relational analysis
, Article Solar Energy ; Volume 215 , 2021 , Pages 492-507 ; 0038092X (ISSN) ; Parcheforosh, A ; Salari, A ; Ma, T ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
The solar collectors absorb solar irradiation and then produce thermal energy; however, they cannot generate electrical power. Electricity and thermal energy can be produced by the photovoltaic thermal module, simultaneously, while the outlet temperature of the photovoltaic thermal module is not usually high enough to provide thermal requirements of a building such as hot water or space heating. This work proposes a novel compound system created by the connection of a solar collector in series with a photovoltaic thermal module to resolve the issue of low outlet temperature in the photovoltaic thermal module and lack of electrical power in solar collectors. To examine the feasibility of this...
A novel energy storage system for latent heat recovery in solar still using phase change material and pulsating heat pipe
, Article Renewable Energy ; Volume 163 , 2021 , Pages 2115-2127 ; 09601481 (ISSN) ; Rajabi Ghahnavieh, A ; Shafii, M. B ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In this study, a latent heat storage unit and built-in condenser were integrated with a solar still. Storage of dissipated latent heat of vapor during the day and using it after sunset prolongs system operation. During the day, the entire solar radiation was consumed to heat the saline water and only the heat coming from the condensation of vapor was stored in the phase change material (PCM). The dissipated heat from the condenser body was transferred to the PCM and stored. Additionally, the existence of PCM on the outer surfaces of the condenser prevented the rise of condenser wall temperature during the day and kept the condenser temperature low. After sunset, the heat stored in the PCM...
A feasibility study of solar-powered reverse osmosis processes
, Article Desalination ; Volume 500 , 2021 ; 00119164 (ISSN) ; Shirvani, H ; Alamolhoda, A. A ; Farhadi, F ; Karimi, M ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The use of solar-powered reverse osmosis desalination systems is a sustainable and environmentally friendly solution in the desalination industry. However, there are some substantial technical and economic challenges due to the intermittency and fluctuation of solar energy. Recent technological improvement and feed-in tariff policies enable these systems to be competitive with conventional grid-connected reverse osmosis systems. In this paper, a feasibility study of the integration of solar panels with the grid to power small-scale reverse osmosis systems (namely up to 2000 m3/day) is conducted in Iran, as a country with a low price of electricity. For this purpose, a city located on the...
Modeling and techno-economic study of a solar reverse osmosis desalination plant
, Article International Journal of Environmental Science and Technology ; Volume 19, Issue 9 , 2022 , Pages 8727-8742 ; 17351472 (ISSN) ; Hajialigol, P ; Boroushaki, M ; Shafii, M. B ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
In this research, the design of a solar reverse osmosis desalination plant was investigated by integrating various components using TRNSYS and ROSA software. To this goal, a two-stage reverse osmosis system with 50% recovery in the city of Chabahar was modeled. The calculations were performed in three different case studies, i.e., a photovoltaic power plant, a solar collector power plant with Organic Rankine Cycles, and a photovoltaic thermal power plant with Organic Rankine Cycles, with the reverse osmosis desalination plant being a novel investigation. Water production and electrical energy generation of each case study were evaluated both on a daily and yearly bases. The simulation...
Prioritization of solar electricity and hydrogen co-production stations considering PV losses and different types of solar trackers: A TOPSIS approach
, Article Renewable Energy ; Volume 186 , 2022 , Pages 889-903 ; 09601481 (ISSN) ; Rezaei, M ; Mostafaeipour, A ; Goojani, A.R ; Saghaei, H ; Hosseini Dehshiri, S. J ; Hosseini Dehshiri, S. S ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Renewable hydrogen production plays a key role in transitioning to a hydrogen economy. For this, developing countries are encouraged to keep up with industrialized nations. As such, this study seeks to evaluate the potential of all capital cities of Iran in terms of solar-based hydrogen production and prioritize the nominated alternatives. This step is highly valued because finding the most suitable place for this purpose can lead to substantial outcomes and consequently avoid failure. Therefore, here a 20-kW solar power plant is simulated by PVsyst 6.7 software and meteorological data of 31 capital cities is extracted using Meteonorm 7.1 software. Considering all losses associated with...
Application of hybrid nanofluids in a novel combined photovoltaic/thermal and solar collector system
, Article Solar Energy ; Volume 239 , 2022 , Pages 102-116 ; 0038092X (ISSN) ; Salari, A ; Ma, T ; Lu, H ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Because of the low outflow temperature of the conventional photovoltaic thermal systems and lack of electrical production of the solar thermal collectors, a novel combined system is proposed to solve the two mentioned drawbacks. This novel system is achieved by connecting a photovoltaic thermal unit to a solar thermal collector in series. To increase the overall performance of this novel combined system, different hybrid nanofluids include (1) multiwall carbon nanotube-aluminum oxide (2) multiwall carbon nanotube-silicon carbide (3) graphene-aluminum oxide, and (4) graphene-silicon carbide are compared. The investigation is performed based on the three-dimensional simulation, and the...
Optimal deployment of renewable electricity technologies in Iran and implications for emissions reductions
, Article Energy ; Volume 91 , 2015 , Pages 882-893 ; 03605442 (ISSN) ; Shafiei, E ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
In this paper, special focus is paid to the long-term adoption of renewable electricity technologies and their implications for emissions reductions in Iran. MESSAGE, as a bottom-up energy supply optimization model, is used to assess the lowest-cost technology options. The potential impacts of transitioning to a renewable electricity supply are quantified, and the investment requirement to achieve a low-carbon generation mix is estimated. Alternative scenarios are defined to evaluate the impact of fossil fuel prices, the carbon tax and government incentives on the utilization of renewable resources, national renewable targets, and emissions reductions. The prioritization of non-hydro...
Synthesis of mesoporous TiO2 structures through P123 copolymer as the structural directing agent and assessment of their performance in dye-sensitized solar cells
, Article Solar Energy ; Volume 133 , 2016 , Pages 24-34 ; 0038092X (ISSN) ; Mozaffari, N ; Sharif University of Technology
Elsevier Ltd
Abstract
A novel and efficacious strategy was implemented for creation of mesoporous TiO2 films and powder through an integration of sol-gel and evaporation-induced self-assembly (EISA) processes aided by triblock Pluronic P123. A mesoporous crack-free thin film with virtual thickness of 300 nm was attained under 10% relative humidity aging, for 72 h at the low temperature of 5 °C. Further, the TiO2 film with porous structure has been formed from conventional paste, exploiting as-prepared mesoporous titania powder. The X-ray Diffraction (XRD) of synthesized mesoporous powder disclosed formation of anatase phase as well as rutile phase, in such a manner that the latter constituted a very small...
Techno-economic and environmental analysis of an integrated standalone hybrid solar hydrogen system to supply CCHP loads of a greenhouse in Iran
, Article International Journal of Green Energy ; Volume 14, Issue 3 , 2017 , Pages 295-309 ; 15435075 (ISSN) ; Roshandel, R ; Hamidi, A. A ; Sharif University of Technology
Abstract
The techno-economic and environmental performance of hybrid solar hydrogen energy systems was investigated to provide combined cooling, heating and power (CCHP) demands of a standalone greenhouse in Iran to achieve sustainable agriculture based on an optimization procedure. From the environmental point of view, by deploying hybrid energy systems, 83%, to 100% of emissions can be avoided. Also a sensitivity analysis was performed on the hybrid energy systems in order to study the effect of major parameter variation on the systems justification. It was concluded that hybrid solar systems are economically competitive with conventional systems, for high solar intensity locations with high diesel...
Sizing and performance analysis of standalone hybrid photovoltaic/battery/hydrogen storage technology power generation systems based on the energy hub concept
, Article International Journal of Green Energy ; Volume 14, Issue 2 , 2017 , Pages 121-134 ; 15435075 (ISSN) ; Roshandel, R ; Hamidi, A. A ; Sharif University of Technology
Taylor and Francis Inc
2017
Abstract
In this study, the optimal sizing and performance analysis of a standalone integrated solar power system equipped with different storage scenarios to supply the power demand of a household is presented. One of the main purposes when applying solar energy resource is to face the increasing environmental pollutions resulting from fossil fuel based electricity sector. To this end, and to compare and examine two energy storage technologies (battery and hydrogen storage technology), three storage scenarios including battery only, hydrogen storage technology only and hybrid storage options are evaluated. An optimization framework based on Energy Hub concept is used to determine the optimum sizes...
Optimal distribution transformer sizing in a harmonic involved load environment via dynamic programming technique
, Article Energy ; Volume 120 , 2017 , Pages 92-105 ; 03605442 (ISSN) ; Mohiti, M ; Farzin, N ; Vakilian, M ; Sharif University of Technology
Abstract
Installation of a significant number of distributed generators (DGs), besides the application of non-sinusoidal loads such as; Plug-in Hybrid Electric Vehicles (PHEVs), in the emerging smart distribution networks and the industrial plants have posed a major challenge to the existing methods of optimal transformer sizing (OTS). The harmonic currents generated in these new environments not only substantially increase the transformer load losses, but also cause abnormal winding temperature rise and hence transformer excessive loss of life. Therefore, the harmonic contents of the loads currents should be accounted in choosing the appropriate size of distribution transformers. To address this...
Numerical study of hydrogen-air combustion characteristics in a novel micro-thermophotovoltaic power generator
, Article Applied Energy ; Volume 199 , 2017 , Pages 382-399 ; 03062619 (ISSN) ; Saidi, M. H ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
In the present work, a micro combustor for thermophotovoltaic (TPV) devices is proposed which is included a U-shaped microtube in a box with a secondary fluid in space between U-shaped microtube and box walls. By utilizing the three-dimensional CFD model, combustion characteristics of the premixed lean hydrogen-air mixture in the present micro combustor are studied numerically with detailed chemistry and transport taking into account heat transfer through the wall. The results show that the establishment of secondary flows and better preheating in the curved tubes is caused the flammability limits to be at least four times in comparison with straight tubes. Combustion characteristics are...