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Impact of correlation on reserve requirements of high wind-penetrated power systems
, Article International Journal of Electrical Power and Energy Systems ; Volume 73 , 2015 , Pages 576-583 ; 01420615 (ISSN) ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
This paper investigates the effects of two important factors, i.e., correlation of wind farms output with load and wind speed coincidence in determining the required static reserve in a high wind-penetrated power system. To this end, it suggests an analytical approach to involve the effects of these two factors in probabilistic analytical multi-state models of wind farms output generation. Based on an optimization framework with the objective of reaching the desirable level of correlation, the key idea is to calculate some joint probabilities for equivalent models of wind farms. As a result, these models become compatible with the ones for conventional generation units in adequacy studies of...
A new semi-empirical wind turbine capacity factor for maximizing annual electricity and hydrogen production
, Article International Journal of Hydrogen Energy ; Volume 45, Issue 32 , 2020 , Pages 15888-15903 ; Mostafaeipour, A ; Rezaei, M ; Jahangiri, M ; Mehrabi, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The capacity factor is an important wind turbine parameter which is ratio of average output electrical power to rated electrical power of the wind turbine. Another main factor, the AEP, the annual energy production, can be determined using wind characteristics and wind turbine performance. Lower rated power may lead to higher capacity factor but will reduce the AEP. Therefore, it is important to consider simultaneously both the capacity factor and the AEP in design or selecting a wind turbine. In this work, a new semi-empirical secondary capacity factor is introduced for determining a rated wind speed at which yearly energy and hydrogen production obtain a maximum value. This capacity factor...
Determining the Optimal Level of Reserve in Power Systems with High Penetration of Wind Energy
, M.Sc. Thesis Sharif University of Technology ; Abbaspour Tehrani Fard, Ali (Supervisor) ; Fotuhi-Firuzabad, Mahmud (Co-Advisor)
Abstract
Shortage in fossil fuels resources together with the pollution concerns have caused a systematic change in power system planners and decision makers policies to renewable energies as an alternative to produce electrical energy. However, some intrinsic features of the wind energy overshadow its profitability. Inability to predict the wind speed changes and consequently the output level of wind turbines, being an uncontrollable generation unit, and also being an intermittent unit can be accounted as the main attributes of renewable-based units. Taking into account these features, one can conclude that new challenges can be brought into existence in planning and operation issues of...
Modeling changes in wind speed with height in Iran's cities and its impact on the energy production
, Article Journal of Renewable and Sustainable Energy ; Volume 7, Issue 2 , 2015 ; 19417012 (ISSN) ; Boroushaki, M ; Hannani, S. K ; Sharif University of Technology
Abstract
The estimation of the wind resource at the hub height of a wind turbine is one of the primary goals of site assessment. Since in a majority of cities the wind speed is measured at lower heights, the power law model is applied to estimate the wind speed at higher heights. In this study, the wind data for 10 cities in Iran have been analyzed over a period of one year. The accuracy of the power law model to estimate the wind speed has been examined with variations of height and time during this year. The energy production of a wind turbine using the measured wind speeds and the speeds estimated by the power law model were compared. The measured data revealed that in some cities the wind speed...
Louver and window position effect on cross-ventilation in a generic isolated building: A CFD approach
, Article Indoor and Built Environment ; Volume 31, Issue 6 , 2022 , Pages 1511-1529 ; 1420326X (ISSN) ; Barzkar, E ; Sharif University of Technology
SAGE Publications Ltd
2022
Abstract
Natural ventilation has been used to increase indoor air quality, remove pollutants, and remove heat absorbed in the building structure. Some architectural features such as wind-catcher systems are used to induce airflow into buildings, and openings equipped with louvers are employed to reduce solar daylight while allowing natural ventilation. Earlier studies on ventilated louvers and wind-catchers have shown the impact of the louvers’ opening positions and slat angles. However, their combination with each other has been less studied. This paper presents CFD simulations of cross-ventilation in a generic isolated building integrated with a one-sided roof-top wind-catcher and the outlet...
Starting improvement of micro-wind turbines operating in low wind speed regions
, Article International Journal of Green Energy ; Volume 14, Issue 11 , 2017 , Pages 868-877 ; 15435075 (ISSN) ; Gooya, M ; Hosseini, S. V ; Pourrajabian, A ; Sharif University of Technology
Abstract
The study deals with the design and optimization of external and internal geometry of micro-wind turbines blades. A specified objective function which consists of the power coefficient and the starting time was defined and the genetic algorithm optimization technique in conjunction with the blade-element momentum theory was adopted to find the geometry of the blades including the distributions of the chord, the twist angle and also the shell thickness. Moreover, the allowable stress of the blades was considered as a constraint to the objective function. Results show that a reasonable compromise is achievable such that the starting time of the blades reduces noticeably in return for a small...
Modelling and Electromechanical Control of Variable Speed wind Turbine in Order to Gain Maximum Wind Power
, M.Sc. Thesis Sharif University of Technology ; Moradi, Hamed (Supervisor)
Abstract
In this research, the main purpose of the controller design is in the second region of operation of a wind turbine, which involves absorbing the maximum energy from the wind. WindPACT 1.5MW turbine has been investigated and the power coefficient of this turbine has been obtained using WT-PERF and FAST softwares. Simulations show that the results of both methods are well matched. Then, using ANFIS, a method for estimating the wind speed is derived from the data obtained by FAST. Inputs to the ANFIS system are the turbine aerodynamic power, rotor speed and blade pitch angle while the output of ANFIS system is the estimated wind speed. The maximum power coefficient of the wind turbine occurs...
Relationship between Dust Outbreaks and Soil Moisture in the Urmia Lake Periphery
, M.Sc. Thesis Sharif University of Technology ; Tajrishi, Masoud (Supervisor)
Abstract
Desiccation of different salty lakes around the world has been considered as one of the most critical environmental events. Gradual desiccation of the Lake Urmia and retreatment of its shoreline with respect to ecological level (1274.1 meters) have resulted in new hotspots for dust outbreaks, especially in east and south-east peripheries, which were previously under water. These areas, part of which are salty, are now exposed to open air and susceptible to wind-erosion. Soil moisture, as one of the most important parameters for dust prevention, determines the threshold friction wind speed over playa because it increases the cohesion between soil particles. Therefore, compared with dry soil,...
Numerical Investigation of the Effects of Environmental Parameters on the Simulation of Spread of Fire in Grasslands
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor) ; Afshin, Hossein (Co-Supervisor)
Abstract
Fire in Grasslands is one of the most dangerous natural disasters that is uncontrollable at the time of its occurrence and will continue until there is a fundamental change in the conditions of the fire. Fire in Grasslands due to the high density of vegetation can produce a large amount of heat energy in a short time and in a very large area, which alone can cause the spread of fire in Grasslands. Today, numerical studies of fire behaviour and propagation are given more attention than experimental studies due to their lower costs and limitations. In the present study, the numerical simulation of the fire spread with the influence of climate parameters such as humidity, rainfall during fire...
Toward a comprehensive model of large-scale dfig-based wind farms in adequacy assessment of power systems
, Article IEEE Transactions on Sustainable Energy ; Vol. 5, issue. 1 , 2014 , p. 55-63 ; ISSN: 19493029 ; Abbaspour, A ; Fotuhi-Firuzabad, M ; Moeini-Aghtaie, M ; Sharif University of Technology
Abstract
With the current focus on energy and environment, efficient integration of renewable energies, especially wind energy into power systems, is becoming essential. Furthermore, to fully capture wind potentials and to recognize the unique characteristics associated with wind energy in power systems adequacy analysis, a profound inquiry is required. In this way, this paper tries to establish a comprehensive analytical approach for reliability modeling of doubly-fed induction generator (DFIG)-based wind farms. First, the most impressive components of wind turbines are introduced. It then continues with integrating developed state space model of wind turbines and their production uncertainties,...
Toward a comprehensive model of large-scale dfig-based wind farms in adequacy assessment of power systems
, Article IEEE Transactions on Sustainable Energy ; Vol. 5, issue. 1 , 2014 , p. 55-63 ; Abbaspour, A ; Fotuhi-Firuzabad, M ; Moeini-Aghtaie, M ; Sharif University of Technology
Abstract
With the current focus on energy and environment, efficient integration of renewable energies, especially wind energy into power systems, is becoming essential. Furthermore, to fully capture wind potentials and to recognize the unique characteristics associated with wind energy in power systems adequacy analysis, a profound inquiry is required. In this way, this paper tries to establish a comprehensive analytical approach for reliability modeling of doubly-fed induction generator (DFIG)-based wind farms. First, the most impressive components of wind turbines are introduced. It then continues with integrating developed state space model of wind turbines and their production uncertainties,...
Fuzzy modeling techniques and artificial neural networks to estimate annual energy output of a wind turbine
, Article Renewable Energy ; Volume 35, Issue 9 , September , 2010 , Pages 2008-2014 ; 09601481 (ISSN) ; Ranjbar, A. M ; Sharif University of Technology
2010
Abstract
The purpose of this article is to develop a new method to estimate annual energy output for a given wind turbine in any region which should be easy to use and has satisfactory accuracy. To do this, hourly wind speeds of 25 different stations in Netherlands, output power curve of S47 wind turbine and fuzzy modeling techniques and artificial neural networks were used and a model is developed to estimate annual energy output for S47 wind turbine in different regions. Since this model has three inputs (average wind speed, standard deviation of wind speed, and air density of that region), this model is easy to use. The accuracy of this method is compared with the accuracy of conventional methods...
Dynamic behavior and transient stability analysis of fixed speed wind turbines
, Article Renewable Energy ; Volume 34, Issue 12 , 2009 , Pages 2613-2624 ; 09601481 (ISSN) ; Parniani, M ; Sharif University of Technology
Abstract
This paper analytically investigates the dynamic behavior of fixed speed wind turbines (FSWTs) under wind speed fluctuations and system disturbances, and identifies the nature of transient instability and system variables involved in the instability. The nature of transient instability in FSWT is not similar to synchronous generators in which the cause of instability is rotor angle instability. In this paper, the study of dynamic behavior includes modal and sensitivity analysis, dynamic behavior analysis under wind speed fluctuation, eigenvalue tracking, and using it to characterize the instability mode, and investigating possible outcomes of instability. The results of theoretical studies...
Operational reliability studies of power systems in presence of energy storage systems
, Article IEEE Transactions on Power Systems ; 2017 ; 08858950 (ISSN) ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Abstract
This paper mainly focuses on operational reliability studies of modern power systems taking into consideration the effects of energy storage systems (ESSs). The aim is to develop a new evaluation tool to assess the effects of different factors such as penetration rate, operational strategies and capacities of the ESSs in determining the role of these systems as an operating reserve resource. In this regard, at first, some modifications are made to the PJM method aimed to precisely model the short-term variability in output generation of wind farms in reliability studies. Then, this algorithm is employed to examine the effects of ESSs operating strategies in operational reliability level of...
Operational reliability studies of power systems in the presence of energy storage systems
, Article IEEE Transactions on Power Systems ; Volume 33, Issue 4 , July , 2018 , Pages 3691-3700 ; 08858950 (ISSN) ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
This paper mainly focuses on operational reliability studies of modern power systems taking into consideration the effects of energy storage systems (ESSs). The aim is to develop a new evaluation tool to assess the effects of different factors such as penetration rate, operational strategies, and capacities of the ESSs in determining the role of these systems as a source of operating reserve. In this regard, at first, some modifications are made to the Pennsylvania-New Jersey-Maryland (PJM) method aimed to precisely model the short-term variability in output generation of wind farms in reliability studies. Then, this algorithm is employed to examine the effects of ESSs operating strategies...
Internalizing the social cost of noise pollution in the cost analysis of electricity generated by wind turbines
, Article Wind Engineering ; Volume 30, Issue 6 , 2006 , Pages 521-529 ; 0309524X (ISSN) ; Bahadori, M. N ; Sharif University of Technology
2006
Abstract
The Social Cost of nuisance noise from a wind turbine is defined here as the additional cost to reduce the noise level at a receptor to an exceptable, non-nuisance value, i.e. to mitigate this cost. This acceptable sound level is considered to be 35 dB. Our example is a 10-kW (nominal power) wind turbine considered to supply the electrical energy needs of a 3-storey residential building in Tehran and Manjil. The turbine generates sound at 75 dB. To reduce the sound level at the third floor of the building to 35 dB, it was necessary to increase the height of the turbine from 24 m to 48 m. The initial installed cost of the turbine thereby increased from US$45.000 to US$55,000. The cost of...
Small-Signal stability analysis of DFIG-based wind turbines equipped with auxiliary control systems under variable wind speed
, Article 2020 IEEE International Conference on Environment and Electrical Engineering and 2020 IEEE Industrial and Commercial Power Systems Europe, EEEIC / I and CPS Europe 2020, 9 June 2020 through 12 June 2020 ; 2020 ; Parniani, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
Providing ancillary services such as frequency support and power operating reserve by doubly fed induction gener-ator-based wind turbines has received considerable attention in the recent years, and several auxiliary controllers have been proposed to provide these services. In this paper, small-signal stability of wind turbines equipped with these controllers is assessed in presence of a frequency event and varying wind speed conditions. For this purpose, first, several auxiliary controllers are discussed, and a unified auxiliary controller (UAC) is proposed, which can represent all of these controllers simultaneously. Then, the overall transfer function from the wind speed to the wind...
Reliability Assessment of Wind Power Density in Khouzestan Province
, M.Sc. Thesis Sharif University of Technology ; Moghim, Sanaz (Supervisor)
Abstract
This study seeks to evaluate reliability of wind power density over Khouzestan province using WRF simulations. Based on 10 meter wind speed data extracted from eight synoptic stations over Khouzestan province, two different domains were selected in south and south-west of khouzestan as promising regions with strong wind speeds. WRF model were used to simulate atmospheric data during 2016 and over two selected regions with 2 kilometers grid spacing. Simulated data were verified with comparing to in-situ data via three parameters of RMSE, BIAS and correlation. Results indicate that model configuration had acceptable accuracy in simulating wind speed data. In this study, Monte Carlo...
Performance of a standalone wind-hydrogen power system for regions with seasonal wind profile: A case study in Khaf region
, Article Sustainable Energy Technologies and Assessments ; Vol. 7 , September , 2014 , pp. 265-278 ; ISSN: 22131388 ; Rezaei Mirghaed, M ; Roshandel, R ; Sharif University of Technology
Abstract
The present study was aimed at performance and energy analysis of a hybrid wind-hydrogen power system. Such system consists of wind turbines, batteries for the short time energy storage, electrolyzer, fuel cell and hydrogen tank for long time energy storage. The proposed configuration is used to supply energy demand of a region with discrete seasonal wind speed regime. Temporary wind energy profiles restrict using batteries for electricity storage as they lose much electrical stored energy for the long time. Based on direct wind turbine usage, batteries and hydrogen storage, different energy supply strategies are introduced and analyzed to power the household electricity demand. The energy...
A neural network-based model for wind farm output in probabilistic studies of power systems
, Article 21st Iranian Conference on Electrical Engineering, ICEE 2013 ; 2013 , 14-16 May ; 9781467356343 (ISBN) ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Abstract
The penetration of wind energy in power systems has been growing due to its interminable and mild environmental effects. The intrinsic attributes of this environmentally-friendly energy, i.e., the stochastic nature of wind farms generation, however, imposes various technical and financial challenges into power systems. So, developing an accurate wind farm modeling approach aimed at taking into account the wind generation intermittency can relieve many of these challenges. Therefore, this paper takes a step to an efficient wind farm modeling procedure employing an accurate as well as well-known Neural Network (NN)-based tool. The proposed approach is comprised of two main steps. The wind...