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    Control of a Distributed Generation System Comprising Wind Turbine, Photovoltaic Array, and Fuel Cell in Standalone

    , M.Sc. Thesis Sharif University of Technology Shirazi, Moein (Author) ; Zolghadri, Mohammad Reza (Supervisor) ; Karimi, Houshang (Supervisor)
    On account of the exhausting nature and increasing daily cost of the fossil fuels, it seems that replacing the fossil fuels by an alternative source of energy is inevitable. Moreover, in the remote areas that the electricity network is not accessible, the use of distributed sources (DSs) such as solar energy and wind energy is advantageous. Continuity of the supply and voltage control of the load in spite of the stochastic nature of the generated power of the renewable energy resources are the main concerns in the distributed generation (DG) systems. In this thesis, stand-alone operation of a DG unit comprising a solar unit and wind turbine as primary sources of energy is considered. A... 

    Robust Multivariable Control of Electro-mechanical System in Horizontal Wind Turbines under Off-design Conditions

    , M.Sc. Thesis Sharif University of Technology Faraji Nayeh, Reza (Author) ; Vosughi Vahdat, Bijan (Supervisor) ; Moradi, Hamed (Supervisor)
    Advanced control techniques are required to achieve a cost-effective and reliable use of the wind power generation. The wind turbines are generally controlled based on two control objectives: the turbine protection and the generation of acceptable power for the utility grid. These objectives are achieved if the control inputs are applied based on appropriate control logics. In this work, a nonlinear multivariable model of the wind turbine with a DFIG generator is considered. The rotor speed and the d-axis rotor current (as the control outputs) are controlled via manipulation of the two generator voltages (as the control inputs) in low wind velocity condition. For high wind velocity, the... 

    Robust Power Control of Wind Turbine with Smooth Switching between Operational Regions using a Two-mass Model

    , M.Sc. Thesis Sharif University of Technology Nouriani, Ali (Author) ; Moradi, Hamed (Supervisor)
    Wind turbines have been the subject of many researches in recent decades. Optimization and continuous improvement of these systems play a decisive role in the development and exploitation of wind farms. Wind turbines can be studied from several aspects such as structure, dynamics, aerodynamics, electricity and control. In this research, robust power control of the wind turbine has been studied with emphasis on accurate 2 DOF mechanical and aerodynamic modeling. Aerodynamic coefficients of the turbine have been calculated using the numerical methods and the effect of this numerical modeling has been studied in comparison with the analytical methods on the turbine power control. Several new... 

    Adaptive Robust Control of Floating Offshore Wind Turbines

    , M.Sc. Thesis Sharif University of Technology Izanloo, Mohammad (Author) ; Sadati, Nasser (Supervisor)
    Nowadays, modern life needs energy resources. In the last few centuries, countries have focused on the use of fossil fuels. However, excessive use of fossil fuels, such as oil and coal, has resulted in enormous environmental hazards. Global warming and air pollution are the most visible manifestations of these hazards. In recent years, energy researchers have been looking for alternative sources. The result of this approach is to pay attention to clean and renewable resources such as wind energy.Wind turbines are used to generate electrical energy out of wind. Among the different types, floating offshore wind turbines have been mostly considered because of various benefits. However, they... 

    Active Control of Edgewise Vibrations in Wind Turbine Blade by Optimization of the Number and Locations of the Intermediate Actuators

    , M.Sc. Thesis Sharif University of Technology Pishbahar, Baher (Author) ; Moradi, Hamed (Supervisor)
    Vibrations in HAWT reduce their efficiency and increase maintenance costs. In this paper, the blade edgewise vibrations are reduced by using several actuators in different parts of the wind turbine blade and optimization of the number and locations of actuators. The wind turbine blade dynamic behavior is investigated by using dynamic modeling. The actuators are trusses that are located inside each blade and apply control force to different parts of the blade. Active control force is applied to reduce edgewise vibrations. The designed controller is applied and simulated on NREL 5MW wind turbine. By applying the controller, the edgewise vibrations of wind turbine blades are significantly... 

    Wind Turbine Power Chain and Yaw Angle Control for Power Regulation and Load Reduction

    , M.Sc. Thesis Sharif University of Technology Alinoori, Pouya (Author) ; Zohoor, Hassan (Supervisor) ; Moradi, Hamed (Supervisor)
    Sustainable energy is an important and necessary subject. A significant number of studies address the increasing energy production ratio per its cost. To this end, first of all we should increase the energy production. Second, damage and costs of production, set up and maintenance must be reduced. Control is one of the most important and effective tools in the way of achieving these purposes. The problem of controlling a wind turbine is generally divided into two sections of controlling the power chain and yaw control. In this research, both subjects have been investigated.Since there are some problems in measuring the wind speed, controlling the power chain requires prediction of the wind... 

    Assessment of Optimal Power Flow (OPF)Uncertainty in Hybrid Wind- PV Power Systems

    , M.Sc. Thesis Sharif University of Technology Aien, Morteza (Author) ; Fotouhi Firouzabad, Mahmoud (Supervisor)
    As a matter of fact, power systems are always faced with a variety of uncertainties. These uncertainties change system parameters in an unwanted manner which may deteriorate the system security and reliability. For instance, a transmission line which is designed for a certain capacity may be suffered as a result of load increment and consequently may influence the normal operation of other network elements. In recent years, as a result of environmental considerations and especially after the oil shock at 1973 which caused the the energy prices to increase unprecedentedly, the human has taken more attention to renewable energies exploitation. Theses energies have a fluctuating nature and are... 

    Condition Monitoring of Wind Turbine Blade Using Fiber Optics

    , M.Sc. Thesis Sharif University of Technology Entessari, Farshid (Author) ; Zabihollah, Abolghasem (Supervisor) ; Behzad, Mehdi (Co-Advisor)
    Over the last decades the attention of the most modern countries about usage of wind has grown due to the recent crisis of energy. This renewable energy source offers a cost effective solution for electricity production. Wind energy is the best candidate among other sources due to wind turbines technology reliability. In order to gain maximum power from wind turbines, their size becomes relatively large, which creates more complexity in their repair and maintenance, furthermore Wind turbine downtime is outside the expectations, which is more costly than corrective maintenance, therefore in order to minimize sudden downtimes and related huge maintenance, a reliable monitoring technique must... 

    An Innovative Method to Monitor Power Production Performance of Wind Farms Using Web-GIS Technique

    , M.Sc. Thesis Sharif University of Technology Pouryousefi, Ali (Author) ; Abbaspour, Madjid (Supervisor) ; Mehdigholi, Hamid (Co-Advisor)
    Nowadays because of population growth and limitation of fossil fuels for power generation purpose, utilization of renewable energy sources has become highlighted. According to the geographical situation for use of wind energy, since some areas of Iran are in suitable conditions the manufacture of wind turbines and installation in wind farms has been under development recently. Monitoring the performance and operation of turbines and wind farms is an inevitable matter. Because of the suitable geographical location of Iran and pursuant to fair wind potential sites widespread this country, this phenomenon requires some backgrounds in many aspects to be achieved. One of the most important... 

    Study of Mechanical Response of Wind Turbine Blades Made of Thermosetting and Thermoplastic Resins

    , M.Sc. Thesis Sharif University of Technology Razaghian, Pardis (Author) ; Abedian, Ali (Supervisor)
    This project has been carried out to investigate the feasibility of using thermoplastic materials in constructing large wind turbine blades made of composite materials. By proving the similarity of the mechanical behavior of blades made of thermoplastic and thermosetting composite materials, the possibility of using these materials with better recycling capabilities has been studied. By studying different thermosetting and thermoplastic resins and checking the Processing methods and mechanical properties of thermoplastic resins, the materials for blades have been selected. The suitable manufacturing method for producing large blades with dimensions above 30 meters is the vacuum-assisted... 

    Study and Simulation of Vacuum-assisted Thermoplastic Resin Infusion Network for a Wind Turbine Blade

    , M.Sc. Thesis Sharif University of Technology Sharifan, Mostafa (Author) ; Abedian, Ali (Supervisor)
    In recent years, much attention has been paid to wind energy and the expansion of wind farms to replace fossil fuels with this energy source. Wind turbine blades are currently made of composite materials using thermoset matrices. These materials are not recyclable, and it is impossible to return their resins or fibers to the production cycle. In this research, an attempt has been made to replace thermoset resins with thermoplastic materials that can be recycled. In the following, manufacturing and performance aspects of thermoplastic resins have been examined, and the optimal material has been selected using the modified fuzzy logic method (MFLM). In this study, reactive processing of... 

    Effects of Wind Shear Flow on the Aeroelastic Performance of a Large-Scale Wind Turbine with UBEM

    , M.Sc. Thesis Sharif University of Technology Hossein, Amir Hossein (Author) ; Ebrahimi, Abbas (Supervisor) ; Taeibi-Rahni, Mohamad (Supervisor) ; Rezaei, Mohamad Mahdi (Co-Supervisor)
    Study of the structural flexibility of large-scale wind turbine components on aeroelastic performance is important under the existence of critical atmospheric conditions. Prediction and control the critical deformations, identifying maximum local deformation and modeling the forces involved, are required. Aeroelasticity analysis is a suitable method for studying the coupling effects of wind turbine aerodynamics, dynamics and structures. This research has been done by modeling wind turbine components including blades, hub, nacelle and tower, taking into account aerodynamic couplings, dynamics and structures. Considering the large scale of reference wind turbine, nonlinear equations have added... 

    Participation of DFIG based Wind Turbines in Power System Frequency Response Improvement

    , Ph.D. Dissertation Sharif University of Technology Ashourizadeh, Alireza (Author) ; Ranjbar, Ali Mohammad (Supervisor)
    Fast improvements in the wind turbine technologies as well as the growing concern over sustainable power supply have led to the proliferation of wind energy. The upward trend in installed wind capacity is evident from the fact more than 120 GW of wind turbine capacity has been installed globally in 2018-2019, resulting in 591 GW of globally available wind capacity. The high penetration of renewable resources such as wind-turbine generators can cause inevitable changes in the dynamic behavior of power grids, especially in the frequency stability. Accordingly, it is imperative to perform comprehensive studies about the impacts of wind power on the power system frequency. Increasing wind... 

    Reliability Model of Wind Turbine System with BDFG

    , Ph.D. Dissertation Sharif University of Technology Arabian, Hooman (Author) ; Oraee, Hashem (Supervisor) ; Fotuhi Firouzabad, Mahmud (Supervisor)
    Considerable attention has been given in recent years to renewable energy sources due to concerns about dwindling fuel reserves and the potential impact of conventional energy systems on the environment. Wind power is one form of renewable energy resources and also considered as Dispersed Generation (DG). Widespread utilization of wind power imposes many effects on planning and operation of power system. In other side, reliability evaluation and enhancement is an important factor in modern power system planning and operation. So, reliability assessment of wind turbines is of great importance and will receive more attention in the future according to increase of WT utilization. The... 

    Modeling and Structural Health Monitoring of 5 MW Wind Turbine Based on Moving Principal Component Analysis

    , M.Sc. Thesis Sharif University of Technology Majidi Pishkenari, Mohsen (Author) ; Abedian, Ali (Supervisor)
    Nowadays, the structural health monitoring is considered as an essential element in improving the performance of the structures. The role and importance of the issues in this area have been reached to the point that different ideas and policies are developed for the safety margin over the useful life of the structures. To analyze more accurately, a real model of a turbine blade is required. This issue would be taken into more consideration when the scale of the turbine gets larger. Changing of the design philosophies over time results in effective changes in the design process and maintenance procedures. Any single of these inspections has different importance according to users' demands. In... 

    Vibration Modeling and Analysis of a Wind Turbine Blade based on Third-Order Structural Nonliearities

    , Ph.D. Dissertation Sharif University of Technology Rezaei, Mohammad Mahdi (Author) ; Behzad, Mehdi (Supervisor) ; Haddadpour, Hassan (Co-Advisor) ; Moradi, Hamed (Co-Advisor)
    Aiming to improve the extraction performance of wind energy has led to the noticeable increase of the structural dimensions in the modern wind turbines. The larger blade with more flexibility experiences large structural deformation even under nominal operational loading, so the nonlinear modeling and analysis of these structures have become as important subject of the recent wind turbine researches. In this dissertation, the geometrical exact model of the rotating wind turbine blade under the effects of the tower tip's motion, and also the operational loading comprising the aerodynamic and gravitational loadings is presented. In this way, the geometrical exact beam formulation is developed... 

    Wind Farm Modeling for Power System Stability Studies

    , M.Sc. Thesis Sharif University of Technology Mirnezhad, Hosein (Author) ; Parniani, Mostafa (Supervisor)
    Considering the continuous growth of renewable energy sources in electric grids, the importance of utilizing simple, generic, and upgradable models for different network stability studies is increasing. In recent years, generic and standard wind turbine models for transient and short-term frequency and voltage stability studies have been developed. In this regard, researchers are still working on promotion of the generic models, especially to expand them for unbalanced transient studies, improve the transient response, and include inertia response. In this thesis, different methods for generic modeling of wind turbines are surveyed and the development procedure of WECC and IEC generic model... 

    Distribution Load Modeling Incorporating Distributed Generations and Studying its Side Effects

    , M.Sc. Thesis Sharif University of Technology Rastegar Moghaddam, Vahid (Author) ; Fotuhi-Firuzabad, Mahmud (Supervisor)
    According to the economic and environmental considerations, the use of distributed generation, both renewable and non-renewable type, in distribution networks is increasing. Their power generation is determined either by weather conditions or customers’ control due to their needs, therefore it is beyond the control of dispatcher.
    In this thesis, two common technologies of distributed generations, including wind turbines and micro-CHPs, have been considered and the effects of their generations and penetrations on distribution network load and other network parameters have been evaluated.
    Power generation of micro-CHP units and its side effects, is dependent on the customers’... 

    Numerical Calculation of Air Flow Around and at Wake of the Darrieus Turbine

    , M.Sc. Thesis Sharif University of Technology Ebrahimi Saryazdi, Mohammad (Author) ; Boroushaki, Mehrdad (Supervisor) ; Rajabi, Abbas (Co-Advisor)
    Recently, a lot of attention has been devoted to the use of Darrieus wind turbines because of high power density and environment aspect in urban areas. Turbine airflows don’t effect on the power coefficient of Darrieus turbine. This turbine has an acceptable power coefficient depend on the other wind turbine in the small scale turbine. Aerodynamic performance of a Darrieus turbine is very complex due to phenomena such as dynamic stall and changing forces on the turbine caused by changing horizontal angles. So study airflows around turbine must be preformed. In this thesis the aerodynamics of an H-rotor vertical axis wind turbine (VAWT) has been studied using computational fluid dynamics in... 

    The Effect of Wind Turbine Rotor Deflection on Its Aerodynamic Performance Using Actuator Disc Model

    , M.Sc. Thesis Sharif University of Technology Jalali, Ramin (Author) ; Darbandi, Masoud (Supervisor)
    An aerodynamical model for studying asymmetric and three-dimensional flow fields about wind turbine rotors is presented. The developed algorithm combines a asymmetric and three-dimensional Navier-Stokes solver with a so-called actuator disc technique in which the loading is distributed along lines representing the blade forces. The loading is determined iteratively using a bladeelement approach and tabulated airfoil data. Computations are carried out for a 5MW NREL wind turbine equipped with three blades. The computed power production is found to be in good agreement with measurements. The computations give detailed information about basic features of wind turbine wakes, including...