Economic evaluation of micro-turbines in Iranian electric industry

, Article 2007 IEEE Lausanne POWERTECH, Lausanne, 1 July 2007 through 5 July 2007 ; 2007 , Pages 1776-1779 ; 9781424421909 (ISBN) Siahkali, H ; Sharif University of Technology

2007

Abstract

Today the electric utility industry is being restructured from monopoly and regulated structure to competitive and deregulated structure. Changes in electricity markets, in technology, economics and regulatory structures have created a new interest in small-scale generation and efficiency resources, dispersed throughout the lower voltage networks. Many reasons have been developed and encouraged using DG (Distributed Generation) in different countries such as power system restructuring, DG technologies advances and price increases. The most important problems of many developing countries is the high cost of finance and limited access to financial resources because of the electric industry is...

Assessment of power quality indexes in Tehran distribution company

, Article 2007 IEEE Lausanne POWERTECH, Lausanne, 1 July 2007 through 5 July 2007 ; 2007 , Pages 1905-1910 ; 9781424421909 (ISBN) Siahkali, H ; Sharif University of Technology

2007

Abstract

Power quality has become an increasing concern to utilities and customers. The increased concern has resulted in measuring power quality variations and characteristic disturbances for different distribution companies. This paper explains the results of power quality indexes for 50 customer loads at two voltage levels 20kV and 400v. The measurement period is 7 days with 10 minutes intervals. Also this survey has been presented according to IEC61000 and Iranian Power Quality Standard (IPQS). IPQS has some differences from IEC61000, EN50160 and IEEE standards in power quality indexes, which are investigated in this paper. At the end of paper, individual and global power indicators for all...

Interval type-2 fuzzy modeling of wind power generation in Genco's generation scheduling

, Article Electric Power Systems Research ; Volume 81, Issue 8 , 2011 , Pages 1696-1708 ; 03787796 (ISSN) Siahkali, H ; Vakilian, M ; Sharif University of Technology

2011

Abstract

Wind power is a promising source of electric power generation since it has tremendous environmental and social benefits. The generation scheduling (GS) problem encounters several uncertainties in terms of the system's parameters such as load, reserve and available wind power generation. The modeling of those uncertainties is an important issue in power system scheduling. A fuzzy based modeling approach can be used to develop the generation schedule under an uncertain environment. In this paper, the type-2 fuzzy membership function (MF) is implemented to model the linguistic uncertainty of type-1 MF of available wind power generation which stems from opinions of different experts. The...

Fuzzy generation scheduling for a generation company (GenCo) with large scale wind farms

, Article Energy Conversion and Management ; Volume 51, Issue 10 , 2010 , Pages 1947-1957 ; 01968904 (ISSN) Siahkali, H ; Vakilian, M ; Sharif University of Technology

2010

Abstract

Wind power is a promising alternative in power generation because of its tremendous environmental and social benefits. Generation scheduling (GS) is more important in a power system integrating wind farms. Unlike conventional power generation sources, wind power generators supply intermittent power because of uncertainty in resource. This paper presents a fuzzy approach to the generation scheduling problem of a GenCo considering uncertainties in parameters or constraints such as load, reserve and available wind power generation. The modeling of constraints is an important issue in power system scheduling. A fuzzy optimization approach is an approach that can be used to obtain the generation...

Stochastic unit commitment of wind farms integrated in power system

, Article Electric Power Systems Research ; Volume 80, Issue 9 , Jan , 2010 , Pages 1006-1017 ; 03787796 (ISSN) Siahkali, H ; Vakilian, M ; Sharif University of Technology

2010

Abstract

Integration of wind power generation creates new concerns for operation engineers in a power system. Unlike conventional power generation sources, wind power generators supply intermittent power due to uncertainty in parameters of wind such as its velocity. This paper presents probabilistic model for load and wind power uncertainty which can be used in operation planning (with durations up to one or two years). A stochastic model is proposed to simulate the status of units that are directly affected by the load and wind power generation uncertainties. This paper develops a solution method for generation scheduling of power system, while taking into account the stochastic behavior of the load...

Fuzzy based generation scheduling of power system with large scale wind farms

, Article 2009 IEEE Bucharest PowerTech: Innovative Ideas Toward the Electrical Grid of the Future ; 2009 ; 9781424422357 (ISBN) Siahkali, H ; Vakilian, M ; Sharif University of Technology

2009

Abstract

Wind power introduces a new challenge to system operators. Unlike conventional power generation sources, wind power generators supply intermittent power because of uncertainty in its resource. In a power system involved largescale wind power generation scenario, wind intermittency could oblige the system operator to allocate a greater reserve power, in order to compensate the possible mismatch between predicted and the actual wind power output. This would increase the total operation cost. This paper presents a new approach in fuzzy based generation scheduling (GS) problem using mixed integer nonlinear programming (MINLP). While the reserve requirements, load generation balance and wind...

Electricity generation scheduling with large-scale wind farms using particle swarm optimization

, Article Electric Power Systems Research ; Volume 79, Issue 5 , 2009 , Pages 826-836 ; 03787796 (ISSN) Siahkali, H ; Vakilian, M ; Sharif University of Technology

2009

Abstract

Large-scale integration of wind power in the electricity system presents some planning and operational difficulties, which are mainly due to the intermittent and difficult nature of wind prediction process. Therefore it is considered as an unreliable energy source. This paper presents a new approach for solving the generation scheduling (GS) problem. It will consider the reserve requirement, load balance and wind power availability constraints. The particle swarm optimization (PSO) method is suggested to deal with the equality and inequality constraints in the GS problem. The proposed PSO is applied to a 12-unit test system (including 10 conventional thermal generating units and 2 wind...

Integrating large scale wind farms in fuzzy mid term unit commitment using PSO

, Article 2008 5th International Conference on the European Electricity Market, EEM, Lisboa, 28 May 2008 through 30 May 2008 ; 2008 ; 9781424417445 (ISBN) Siahkali, H ; Vakilian, M ; Sharif University of Technology

2008

Abstract

This paper presents a new approach for unit commitment (UC); where a large scale wind power exists and the wind speed has a fuzzy characteristic; by using particle swarm optimization method (PSO). In this approach, the system reserve requirements, the requirement of having a load balance, and the wind power availability constraints are realized. A proper modeling of these constraints is an important issue in power system scheduling. Since these constraints are "fuzzy" in nature, any crisp treatment of them in this problem may lead to over conservative solutions. In this paper, a fuzzy optimization-based method is developed to solve power system UC problem with a fuzzy objective function and...

Operation Planning in Restructured Power System Integrating Wind /Solar Energy

, Ph.D. Dissertation Sharif University of Technology Siahkali, Hassan (Author) ; Vakilian, Mehdi (Supervisor)

Abstract

In power system operation, the term "operation planning" carries a wide range of meaning. For some utilities, operation planning denotes primarily short-term planning tasks (up to several days), such as load forecasting, unit commitment, hydro-thermal coordination, transaction pricing, fuel allocation, and security analysis while for other companies operational planning is interpreted in a wider context, and include mid-term planning activities (up to several months), such as maintenance planning, fuel budgeting, rate forecasting, network planning, relay coordination, etc. The mid-term planning provides the link between the long-term and short-term planning programs. The duration of this...

Structural Design of a Launch Vehicle with Reusable First Stage

, M.Sc. Thesis Sharif University of Technology Hassan Jamaklu (Author) ; Haddadpour, Hassan (Supervisor)

Abstract

Aerodynamics loads and aeroheating during reentry, are one of the challenging issues in designing One of the main challenges in the design and application of reusable spacecrafts is the aerodynamic and thermal loads acting on their structures during reentry into the atmosphere. For this reason, all the concepts/prototypes presented in the 20th century were either not fully reusable, or were partially canceled, or did not have economic justification. In this report, the aerodynamic loads on the first stage of a launch vehicle during the launch and return phases have been investigated. Due to the fact that the main part of the first stage of the vehicle includes fuel and oxidizer tanks, the...

Optimal Trajectory Correction for Hazardous Near-Earth Asteroids

, M.Sc. Thesis Sharif University of Technology Farsi, Salman (Author) ; Zohoor, Hassan (Supervisor) ; Sayyadi, Hassan (Supervisor)

Abstract

The collision of moderately large asteroids and comets also referred to as Near-Earth Objects (NEO's) with earth would have catastrophic consequences. Such events have occurred in the past and may occur again in the future. However, for the first time in known history, humanity may have the technology required to counter this threat. Methods studied for mitigation of this hazard are based on deflecting asteroid's trajectory and are normally divided into two basic categories: high energy impulsive methods, and long-duration low-thrust methods. Two parts of mission to be optimized are the trajectory of spacecraft to reach the target and the deflection strategy which could be analyzed by the...

A revised version of ACO for cutting stock problem [electronic resource]

, Article International Journal of Industrial Engineering ; Vol 15, No 4 (2008), Pages 341-348 Eshghi, K. (Kourosh) ; Javanshir, Hassan ; Sharif University of Technology

Abstract

The one-dimensional cutting stock problem has many applications in industries and during the past few years has been one of the centers of attention among the researchers in the field of applied operations research. In this paper, a revised version of Ant Colony Optimization (ACO) technique is presented to solve this problem. This paper is a sequel to the previous ACO algorithm presented by the authors. In this algorithm, according to some probabilistic rules, artificial ants will select cutting patterns and generate a feasible solution. Computational results show the high efficiency and accuracy of the proposed algorithm for solving one- dimensional cutting stock problem

Control of Car-Like Multi Robots for Following and Hunting of Moving Target

, M.Sc. Thesis Sharif University of Technology Kouhi Gilvan, Hamed (Author) ; Sayyaadi, Hassan (Supervisor) ; Salarieh, Hassan (Co-Advisor)

Abstract

The main purpose of the present thesis is to establish a decentralized controller for some car–like multi robots to follow and hunt moving targets. Robots are very similar to actual cars considering geometric dimensions, mass and moment of inertia and so on; and outputs of the controller are steering-wheel and driving-wheel torques appropriately. Dynamics of the moving target is so that it escapes from the robots. Robots are equipped with antenna for getting wireless sensory signals, including range and bearing sensors. Kalman filter is used for estimation the target relative position and speed and robots state variables. The controller is designed for doing the above mentioned group...

Stock Price Forecasting Using Neural Networks and Fuzzy Logic

, M.Sc. Thesis Sharif University of Technology Alizadeh, Parisa (Author) ; Shavandi, Hassan (Supervisor)

Abstract

This research proposes a novel hybrid method for stock price index forecasting relying on technical analysis, the fundamental analysis of capital market, neural networks technology, and fuzzy logic. The new method shows a good performance comparing complicated and time-consuming forecasting methods. Several factors influence stock price; for example, an important one is the previous trend of stock price. Fortunately, by developing technical analysis and introducing the various indices of this method the maximum use of historical data is made in order to forecast future prices. Another kind of factors is macro-economic variables that their influence on the long-term trends of the stock...

Control of a Group of Mobile Manipulators for Cooperative object Transportation

, M.Sc. Thesis Sharif University of Technology Babaee, Mohammad (Author) ; Sayyadi, Hassan (Supervisor)

Abstract

In this thesis control of wheeled mobile manipulators for cooperative object transportation is investigated. Full dynamic model of a mobile manipulator with a three wheeled mobile base and a three DOF manipulator is derived using Gibbs-Appell method. Input-output linearization technique is used to control individual robots. Transporting the object is divided into two steps, first robots use a decentralized behavior-based method to approach and surround the object. Then virtual structure method is used to control the robots to transport the object cooperatively. Simulation results with three robots handling an object are presented to show the effectiveness of proposed method

Dynamic and Control of Tethered Satellite Systems

, M.Sc. Thesis Sharif University of Technology Yousefian, Peyman (Author) ; Salarieh, Hassan (Supervisor)

Abstract

In this work dynamic behavior of a two body TSS with main satellite as rigid body is studied and effects of tether elasticity and tension on the satellite dynamic are indicated in station keeping phase and circular orbit. Also a simplified modeling is introduced which could be used in nonlinear controller design. Lagrange and extended Lagrange method is used to derive equations of motion. It is shown that longitudinal vibration of tether has small effect on satellite attitude and angular velocity and because of high frequency it can be decoupled from satellite dynamic. In the simplified model, orbital motion is decoupled from equations of TSS and main satellite dynamic. Effect of decoupling...

Analysis of Control of Nonlinear Switched Systems

, M.Sc. Thesis Sharif University of Technology Toorani, Amin (Author) ; Zohoor, Hassan (Supervisor)

Abstract

Separate analysis of modern systems by continuous or discrete theories is not possible, because they cannot solely express the detailed descriptions of a system. As a result of this, researchers are motivated to study hybrid systems. Specific class of hybrid systems which consists of several continuous subsystems and a rule that specifies how to switch between them, is called a switched system. Recently, many studies have been done on the stability and control of switched systems. In this regard, the goal of present study is presenting applications of switched systems using two control methods. The first application is control of a chemical reactor system with multiple modes. We presented...

Design and Analysis of a Cable Based Robot Similar to a Human Hand

, M.Sc. Thesis Sharif University of Technology Abyaneh, Soroush (Author) ; Zohoor, Hassan (Supervisor)

Abstract

The application of manipulators is becoming more and more popular in objects handling especially when it is desired to have access to remote areas in destructive or hazardous taskspaces. For this purpose, a hand-like mechanism must be designed to be used as an end-effector, which can grasp objects. In this paper a cable driven grasping mechanism has been presented. In the proposed mechanism each finger consists of three phalanxes which are actuated by a single motor. Also, locking and unlocking constraints are used in the mechanism in order to generate an anthropomorphic motion, in which, the order of reaching phalanxes to the object is sequential, in such a way that each phalanx starts...

Data Integration with Multiple Ontologies in Semantic Sensor Web

, M.Sc. Thesis Sharif University of Technology Sadeghi, Shahrouz (Author) ; Abolhassani, Hassan (Supervisor)

Abstract

Sensor Observation Service (SOS) which is defined by Open Geospatial Consortium (OGC) Sensor Web Enablement group is a Web service specification in order to standardize the way sensors and sensor data are discovered and accessed on the Sensor Web. Multiple instances of this service can be implemented around the world, providing huge amount of data every moment. Each of these services operates in specific domain of knowledge (thematic), spatial and temporal dimensions. One way to reveal the underlying data over all of them is to provide an architecture for data integration to allow the user to query sensor data without the knowledge of the infrastructure components. In this research, a novel...

Crack Detection on Rotary Elements Using Vibration Analysis

, M.Sc. Thesis Sharif University of Technology Ari, Mostafa (Author) ; Sayyaddi, Hassan (Supervisor)

Abstract

Rotating machinery are found in most industrial units, that are highly susceptible to transverse cross sectional cracks due to fatigue. The vibration pattern of a rotor system reflects the mechanical parameter changes in the system. These vibrations can be used for identifying the cracks and appropriate actions can be taken to prevent more damage to the system. The dynamic behavior of cracked rotor is a subject of considerable current interest. Several researchers have developed models of cracked rotor systems. Therefore, In this thesis, the influence of the presence of transverse cracks in a simple Jeffcott rotor is analyzed. In first, on the basis of fracture mechanics, the direct and...