Development of Computational Fluid Dynamics Model for Spatial Distribution of Greenhouse Temperature and Humidity Considering Plant Evapotranspiration

, M.Sc. Thesis Sharif University of Technology Nikkhah, Amir Farzin (Author) ; Roshandel, Ramin (Supervisor)

Abstract

The purpose of this study is to develop a simulated model of a greenhouse using two different ventilation systems, a fan&pad system and an air-soil converter equipped with a sprinkler in order to compare the cooling performance of these two systems in hot seasons. The main focus of the analysis of the results is on how the temperature and humidity are distributed throughout the greenhouse space. In order to develop a three-dimensional model with computational fluid dynamics method, greenhouse simulation in Ansis software has been used. The development of ventilation model in the greenhouse is done by creating boundary conditions using optimal design. Also, to simulate soil-air conditioning...

Resource Management in Space-Division Multiplexed Elastic Optical Networks

, M.Sc. Thesis Sharif University of Technology Nikkhah, Ali (Author) ; Pakravan, Mohammad Reza (Supervisor)

Abstract

In recent years, Internet traffic has nearly doubled in the core network every two years, and it is expected to continue to grow in the future. With this growth, there is a need for very high capacity and economically efficient transmission systems, which optical communication is the best choice. Elastic optical network (EON) is one of the best options for achieving this goal in the future. Unlike existing networks, the transmission parameters of EON will be customizable, which will have an essential role in optimizing bandwidth assignment. The problem facing scientists today is to approach the final physical capacity of current optical fibers. The solution proposed for this challenge is...

Investigation of in situ prepared polypropylene/clay nanocomposites properties and comparing to melt blending method

, Article Materials and Design ; Volume 31, Issue 1 , 2010 , Pages 76-84 ; 02641275 (ISSN) Baniasadi, H ; Ramazani S. A. A ; Javan Nikkhah, S ; Sharif University of Technology

2010

Abstract

The morphological, physical and mechanical properties of polypropylene/clay nanocomposites (PPCNs) were prepared by in situ polymerization are investigated. Non-modified scmectite type clay (e.g. bentonite) was used to prepare bi-supported Ziegler-Natta catalyst of TiCl4/Mg(OEt)2/clay. Exfoliated PPCNs were obtained by in situ intercalative polymerization of propylene using produced bi-supported catalyst. X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) micrograph were used to assess the clay morphology and dispersion of clay. The crystalline structures of PPCNs were characterized by differential scanning calorimetry (DSC). The mechanical properties of PPCNs were...

Investigation of Production Increasing in In-situ Preparation of Polyolefin/clay Nanocomposites

, M.Sc. Thesis Sharif University of Technology Javan Nikkhah, Sousa (Author) ; Ramazani Saadat Abadi, Ahmad (Supervisor)

Abstract

This project is devoted to experimental investigation of increasing on production of polyethylene/clay nanocomposites (PECNs) and polypropylene/clay nanocomposites (PPCNs) via in-situ polymerization method. First of all we produced bi-supported Ziegler-Natta catalyst to polymerized polyolefins nanocomposites. Bentonite type clay and Magnesiumethoxide (Mg (OEt)2) were used as the support of Tetrachloridetitanium (TiCl4). Catalyst support and polymerization process have been done in slurry phase using Triisobutylaluminum (TiBA) as the co-catalyst. The efficiency of preapared bi-supported Ziegler-Natta was reasonably high (average 200 (gr. Product/mmol Ti. h) for PECNs and 195 (gr. Product/mmol...

Distribution System Resilience Enhancement through Restoration Paths between DERs and Critical Loads

, Article 24th Electrical Power Distribution Conference, EPDC 2019, 19 June 2019 through 20 June 2019 ; 2019 , Pages 1-5 ; 9781728133850 (ISBN) Bahrami, M ; Vakilian, M ; Farzin, H ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2019

Abstract

Hardening and operational measures in electrical distribution systems (EDSs) aim at improving the resilience of EDS in case of natural disasters. This paper proposes a novel two-stage framework for establishing optimal restoration paths for supplying critical loads (CLs) in the aftermath of a natural disaster that will improve the resilience of EDSs. To this end, in the first stage, an algorithm is introduced to find all possible candidate paths between available distributed energy resources (DERs) and CLs, the output of which is applied to the second stage, as the inputs. Subsequently, in the second stage, the problem of finding the optimal restoration paths is modeled as a mixed integer...

Transformer practical turn-to-turn fault detection performance using negative sequence and space vector-based methods

, Article 13th International Conference on Protection and Automation of Power System, IPAPS 2019, 8 January 2019 through 9 January 2019 ; 2019 , Pages 1-6 ; 9781728115054 (ISBN) Farzin, N ; Vakilian, M ; Hajipour, E ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2019

Abstract

Transformer turn-to-turn fault (TTF) is one of the most difficult failures to detect. The negative sequence percentage differential current (NSPD) and extended park vectors approach (EPVA) are the two most promising methods for detection of the TTF inception. In this paper, in order to evaluate the performance of these methods, various experimental tests are carried out to detect the TTF initiation on the winding of the transformer under different operating conditions such as: No-load operation, when an external fault or an open conductor fault is also occurred. The results show that the setting of the proper thresholds plays the main role in the reliable and secure performance of NSPD and...

Practical implementation of a new percentage-based turn-to-turn fault detection algorithm to transformer digital differential relay

, Article International Journal of Electrical Power and Energy Systems ; Volume 121 , 2020 Farzin, N ; Vakilian, M ; Hajipour, E ; Sharif University of Technology

Elsevier Ltd 2020

Abstract

Turn-to-turn fault (TTF) is one of the most prominent reasons for transformer failure. This fault typically initiates by involving only a few turns and can progress to a much more severe fault in a very short time. Therefore, it is critical for the transformer protective relays to detect the TTF in the early stages of its occurrence. The conventional differential relays, in general, cannot detect a minor TTF, and thus, a supplementary protective algorithm is usually required to improve the sensitivity of differential relays against TTFs. This paper proposes a percentage-based fault-related incremental currents method for the precise detection of a low-level TTF. The proposed method employs...

Transformer turn-to-turn fault protection based on fault-related incremental currents

, Article IEEE Transactions on Power Delivery ; Volume 34, Issue 2 , 2019 , Pages 700-709 ; 08858977 (ISSN) Farzin, N ; Vakilian, M ; Hajipour, E ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2019

Abstract

Winding turn-to-turn fault (TTF) is one of the most reported reasons for transformer unplanned outage. If its occurrence is not detected at an early stage, it can develop into a costly phase-to-ground fault. In this paper, a novel algorithm based on the fault-related incremental currents is proposed to detect a low-level transformer TTF. This paper shows that the performance of the proposed method is independent of the transformer operating condition. Therefore, it is reliable even under the presence of power system transients such as the external faults. In addition, the proposed algorithm can be configured uniquely and easily. This feature prevents the algorithm from unnecessary trips....

Reliability Studies of a Smart Distribution System Based on the Concept of Multi-microgrid

, Ph.D. Dissertation Sharif University of Technology Farzin, Hossein (Author) ; Fotuhi Firuzabad, Mahmud (Supervisor)

Abstract

Current trend of energy consumption and aging infrastructure of electricity grids mandates high amounts of investment in transmission and distribution networks. On the other hand, with increased awareness about environmental issues, share of renewable energy resources in power generation portfolio has risen in recent years. Microgrids, as one of the most promising solutions to tackle these issues, are able to accommodate high penetration levels of renewable energy sources and distributed generation in distribution systems. However, microgrids sizes are limited due to some operational considerations and as a result, efficient management of distribution systems with high penetration of...

New Hybrid Approaches Information Clustering Based on FCM Clustering and Optimization CFA

, M.Sc. Thesis Sharif University of Technology Farzin Far, Zohreh (Author) ; Ramezanian, Rasoul (Supervisor)

Abstract

Clustering algorithms are developed to provide general attitudes on database, recognizing latent structures and their more effective accessibility. Recently, broad studies are conducted on clustering since it is recognized as an important tool to explore and analyze data. Clustering is a fundamental learning operation without monitoring in data exploration which divides data into groups of objects so that objects in one group have the most similarity to each other and lowest similarity to objects in other groups. Some clustering algorithms such fuzzy clustering model (FCM) are widely used in clustering problem solution although this technique addresses local optimized searches. Additionally,...

Investigation of properties of polyethylene/clay nanocomposites prepared by new in situ ziegler-natta catalyst

, Article Materials and Design ; Volume 30, Issue 7 , 2009 , Pages 2309-2315 ; 02641275 (ISSN) Nikkhah, S. J ; Ramazani Saadat Abadi, A ; Baniasadi, H ; Tavakolzadeh, F ; Sharif University of Technology

2009

Abstract

This paper is devoted to investigation of morphological and physical-mechanical properties of polyethylene (PE)/clay nanocomposites prepared via in situ polymerization method using bi-supported Ziegler-Natta catalyst. Bentonite type clay and MgCl2 (ethoxide type) were used as the support of TiCl4. Catalyst support and polymerization process have been done in slurry phase using Triisobutylaluminum as the co-catalyst. The microstructure of the nanocomposites was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM indicated that almost fully exfoliated PE/clay nanocomposites were produced successfully using this method. According to permeability...

The Design and Construction of a Marine Current Turbine and Modeling the Flow Around It

, M.Sc. Thesis Sharif University of Technology Nikkhah, Ehsan (Author) ; Seif, Mohammad Saeed (Supervisor) ; Abbaspour, Madjid (Supervisor)

Abstract

Nowadays, science and technology, once again, lead approach to renewable natural resources to access energy due to fossil resources restrictions. Growing need for energy, being concerned about exhaustion of fossil resources, environmental pollution caused by burning fossil materials, climate warming and the greenhouse effect and etc. are obvious evidences of aforesaid fact. On the other hand, oceans and seas are large reservoirs of energy which comes from sunlight, geothermal resources, Earth's rotation and gravity by means of mechanical and hydrothermal processes. During the years, many ideas were conducted to achieve and mine the mentioned enormous energy potential of the oceans and seas....

A comprehensive review on atmospheric water harvesting technologies: From thermodynamic concepts to mechanism and process development

, Article Journal of Water Process Engineering ; Volume 53 , 2023 ; 22147144 (ISSN) Nikkhah, H ; Azmi, W. M. B. W ; Nikkhah, A ; Najafi, A. M ; Babaei, M. M ; Fen, C. S ; Nouri, A ; Mohammad, A. W ; Lun, A. W ; Yong, N. L ; Mahmoudi, E ; Sharif University of Technology

Elsevier Ltd 2023

Abstract

Water scarcity is one of the most challenging problems that the world has ever faced. There are numerous methods to remedy the water crises. One is using atmospheric water harvesting (AWH) to provide water. So far, there is much research on the subject of AWH. However, there is still a lack of establishing an extensive comparison between different technologies and methods used to harvest atmospheric water. In this review, we provide details on the thermodynamic performance of the AWH system. The systems are categorized into both active and passive systems. Heat pumps, membranes, thermoelectric solar systems, and adsorption systems are some atmospheric harvesting technologies that will be...

Reliability evaluation of power grids considering integrity attacks against substation protective IEDs

, Article IEEE Transactions on Industrial Informatics ; Volume 16, Issue 2 , 2020 , Pages 1035-1044 Bahrami, M ; Fotuhi Firuzabad, M ; Farzin, H ; Sharif University of Technology

IEEE Computer Society 2020

Abstract

Secure operation of protective intelligent electronic devices (IEDs) has been recognized as a crucial issue for power grids. By gaining access to substation IEDs, intruders can severely disrupt the operation of protection systems. This paper develops an analytical reliability assessment framework for quantifying the impacts of the hypothesized integrity attacks against protection systems. Petri net models are used to simulate possible intrusion scenarios into substation networks. The cyber network model is constructed from firewall, intrusion prevention system (IPS), and password models, which are three types of defense mechanisms for protecting substation networks. In this paper, two main...

A risk-based resilient distribution system planning model against extreme weather events

, Article IET Renewable Power Generation ; Volume 16, Issue 10 , 2022 , Pages 2125-2135 ; 17521416 (ISSN) Zare Bahramabadi, M ; Ehsan, M ; Farzin, H ; Sharif University of Technology

John Wiley and Sons Inc 2022

Abstract

Due to the accelerated climate change, it is anticipated that the number and severity of natural disasters such as hurricanes, blizzards, and floods will be increased in the coming years. In this regard, this paper presents a distribution system planning model to improve the system resilience against hurricane. A scenario-based mathematical model is proposed to capture the random nature of weather events. Moreover, a stochastic optimization model is developed to simultaneously harden the distribution lines and place different types of distributed generation (DG) units such as microturbines (MTs), wind turbines (WTs), and photovoltaic cells (PVs). The conditional value at risk (CVaR) is used...

An Milp model for switch, DG, and tie line placement to improve distribution grid reliability

, Article IEEE Systems Journal ; 2022 , Pages 1-12 ; 19328184 (ISSN) Zare Bahramabadi, M ; Ehsan, M ; Farzin, H ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2022

Abstract

Remote controlled switches (RCSs) have the ability to isolate the faulted area from other parts of the distribution system. On the other hand, the dispatchable distributed generators (DDGs) and tie lines can supply the interrupted loads after fault occurrence trough microgrids and reduce the outage time. In this regard, this article proposes a planning model for simultaneous placement of RCSs, DDGs, and tie lines to improve distribution system reliability. The presence of renewable distributed generations (RDGs) and energy storage systems, which have an increasing penetration in today's distribution networks are also considered. Moreover, two different practical load shedding methods are...

An MILP model for switch, DG, and tie line placement to improve distribution grid reliability

, Article IEEE Systems Journal ; Volume 17, Issue 1 , 2023 , Pages 1316-1327 ; 19328184 (ISSN) Zare Bahramabadi, M ; Ehsan, M ; Farzin, H ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2023

Abstract

Remote controlled switches (RCSs) have the ability to isolate the faulted area from other parts of the distribution system. On the other hand, the dispatchable distributed generators (DDGs) and tie lines can supply the interrupted loads after fault occurrence trough microgrids and reduce the outage time. In this regard, this article proposes a planning model for simultaneous placement of RCSs, DDGs, and tie lines to improve distribution system reliability. The presence of renewable distributed generations (RDGs) and energy storage systems, which have an increasing penetration in today's distribution networks are also considered. Moreover, two different practical load shedding methods are...

A hierarchical scheme for outage management in multi-microgrids

, Article International Transactions on Electrical Energy Systems ; Volume 26, Issue 9 , 2016 , Pages 2023-2037 ; 20507038 (ISSN) Farzin, H ; Moeini Aghtaie, M ; Fotuhi Firuzabad, M ; Sharif University of Technology

John Wiley and Sons Ltd 2016

Abstract

This paper investigates the operation of a smart distribution system comprised of multiple microgrids during emergency conditions. It proposes a two-stage hierarchical scheme for outage management in such a system to enhance the security of supply during contingencies. This goal is achieved through sharing the available generation and storage capacities among different microgrids. In doing so, a well-organized framework is devised in order to introduce the roles and tasks of each player in operation stage of a multi-microgrids system. Based on this framework, the general optimization model that needs to be evaluated at each stage of the proposed outage management scheme is formulated. In...

Enhancing power system resilience through hierarchical outage management in multi-microgrids

, Article IEEE Transactions on Smart Grid ; Volume 7, Issue 6 , 2016 , Pages 2869-2879 ; 19493053 (ISSN) Farzin, H ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2016

Abstract

This paper proposes a hierarchical outage management scheme to enhance the resilience of a smart distribution system comprised of multi-microgrids against unexpected disaster events. In this regard, after identifying the main features and requirements for a resilient outage management scheme, an appropriate framework is devised and the roles and tasks of different management entities in a multi-microgrids system are introduced. Based on this framework, the microgrids schedule their available resources in the first stage using a novel model predictive control-based algorithm. In the second stage, distribution system operator coordinates the possible power transfers among the microgrids and...

A practical scheme to involve degradation cost of lithium-ion batteries in Vehicle-to-Grid applications

, Article IEEE Transactions on Sustainable Energy ; Volume 7, Issue 4 , Volume 7, Issue 4 , 2016 , Pages 1730-1738 ; 19493029 (ISSN) Farzin, H ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2016

Abstract

This paper concentrates on degradation of electric vehicle (EV) lithium-ion batteries in vehicle-to-grid (V2G) programs and proposes a practical wear cost model for EVs charge scheduling applications. As the first step, all the factors affecting the cycle life of lithium-ion batteries are identified and their impacts on degradation process are investigated. Subsequently, a general model for battery loss of cycle life is devised incorporating all the pertinent factors associated with charging and discharging activities in V2G applications. Modeling the battery wear cost as a series of equal-payments over the cycle life, a mechanism for calculating the cost incurred by EV users due to...