S.E. Kashfi; A. Ebrahimi; S. Kazemi
Abstract
Compliant offshore tension leg platforms (TLP) are adaptive platforms with a vertical mooring system. These types of platforms are usually used in deep water. Adding sufficient initial tension to the mooring, the vertical movements of the structure will be reduced. Tendons, body, and deck are different ...
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Compliant offshore tension leg platforms (TLP) are adaptive platforms with a vertical mooring system. These types of platforms are usually used in deep water. Adding sufficient initial tension to the mooring, the vertical movements of the structure will be reduced. Tendons, body, and deck are different components of this platform, with the body being the most important in terms of hydrodynamic forces, weight, and cost. In this study, an investigation is done on a TLP with a wind turbine by numerical analysis. The boundary element and the finite volume method were carried out in this work in the Caspian Sea. Then the platform was analyzed at a depth of 150 meters, under the influence of wind, current, and irregular waves with one and 100-year return period, and at a zero-degree wave angle. The results of the two numerical approaches are very close and almost identical. The tension leg platform was stable in the different irregular waves. Also, the response amplitude operator calculated using two numerical methods has a good agreement.
Seyyed A. Sina; B. Balanian
Abstract
Multi-Megawatt wind turbines have long, slender and heavy blades that can undergo extremely wind loadings. Good understanding of the modal dynamics of these large machines is of great priority. In this paper, modal dynamics of NREL 5 MW wind turbine is investigated. To this aim, FAST software has been ...
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Multi-Megawatt wind turbines have long, slender and heavy blades that can undergo extremely wind loadings. Good understanding of the modal dynamics of these large machines is of great priority. In this paper, modal dynamics of NREL 5 MW wind turbine is investigated. To this aim, FAST software has been implemented. Vibration characteristics of blades, tower and whole wind turbine machine is extracted. To examine the effects of wind velocity, two operating conditions of machine have been considered. Namely: normal operating condition at rated wind velocity and rated rotor speed and the other, parked condition with fixed rotor at the wind velocity equal to rated wind velocity. Blades root bending moments (both in plane and out of plane) and tower bending moments (both longitudinal and lateral) are extracted. Frequency spectrum of the results is utilized as a tool to study the effects of each vibration mode on wind turbine dynamics in each of aforementioned operating conditions. It is shown that tower vibration during normal operation is highly influenced from blade edge-wise bending mode. On the other hand, during parked condition the effects of flap-wise bending modes become more dominant. The results are expected to offer better predictions of the vibrational behavior of large wind turbines.
Wind Energy
Sh. Mohammadi; A. Maleki; R. Ehsani; O. Shakouri
Abstract
The present study aims to investigate the possibility of using wind energy in some regions of Zanjan province. The current research concentrates on computing the wind energy potential and wind power density. Furthermore, some features related to wind for two locations in Zanjan province have been obtained. ...
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The present study aims to investigate the possibility of using wind energy in some regions of Zanjan province. The current research concentrates on computing the wind energy potential and wind power density. Furthermore, some features related to wind for two locations in Zanjan province have been obtained. Feasibility study of wind energy utilization and computing of wind power density and wind power potential has been widely (Extensively-comprehensively) conducted for Zanjan province. First, two locations in Zanjan province have been considered to analyze the data at a reasonable level of province and to avoid over-focusing on one area. Thereafter, the statistics about wind speed were achieved from the Renewable Energy Organization of Iran in ten-minute intervals and included wind speeds at the heights of 30,10, and 40 m and wind directions at heights of 30 and 37.5 m. Finally, various wind features have been investigated for given locations in Zanjan province. The results demonstrate that the annual wind speed for Soltanieh and Tarom in the height of 40 m were 4.81 m/s and 3.93 m / s, respectively. The highest value U_me and U_mp is calculated, It was observed at a height of 40 m at Soltanie, It is 11.35 m / s and 1.27 m / s, respectively. Also, the performance of several wind turbines in the mentioned areas has been investigated. Finally, a suitable wind turbine has been identified.
R. Rostami; H. Hosseinnia
Abstract
Utilizing distributed generation (DG) units in power system has positive impacts such as: reduction active and reactive power loss, reduce load curtailment, increasing system reliability and reducing the need of installing the new power plant. Wind turbine (WT) is a type of DGs. Employing demand side ...
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Utilizing distributed generation (DG) units in power system has positive impacts such as: reduction active and reactive power loss, reduce load curtailment, increasing system reliability and reducing the need of installing the new power plant. Wind turbine (WT) is a type of DGs. Employing demand side management in a residential, industrial and commercial loads could highlight the role of consumers in managing the total power and increasing the efficiency of system. In this paper the impacts of utilizing WT in improving technical constraints of the reconfigurable distribution system has been evaluated. The Monte Carlo based power flow equation is implemented to the presented scheduling problem. Simulations are done on IEEE 33 bus reconfigurable distribution system