Search results for "wind power"
showing 10 items of 178 documents
Linear parameter‐varying modelling and control of an offshore wind turbine with constrained information
2014
This study deals with linear parameter-varying modelling and output-feedback H ∞ control design for an offshore wind turbine. The controller is designed with consideration that not all the information in the feedback loop will be used. This constraint is incorporated into the design procedure. Constrained information means that a special zero-non-zero pattern is forced upon the gain matrix. The constrained controller is obtained based on parameter-dependent Lyapunov functions and formulated in terms of linear-matrix inequalities. Since the functions are dependent on the wind speed and accurate wind speed measurements are rarely available in practice, an extended Kalman filter is used to est…
Offshore Wind Payload Transfer Using Flexible Mobile Crane
2015
This article presents an offshore-simulated loading and unloading of a payload from a floating platform to a fixed structure. The experiments are performed in a dry-lab, where a Stewart platform is used to simulate the motion of the vessel. A hydraulically actuated vehicle loader crane is used to perform the tasks of payload transfer. The crane includes a hydraulic winch where the wire force is measured by a load cell. A mathematical model of the winch is derived and is experimentally verified. The control strategies include a heave compensation and a constant tension mode. A motion reference unit is used to generate the reference motion of the moving platform. Experimental results show the…
Foundations of offshore wind turbines: A review
2019
Abstract Offshore wind is a source of clean, renewable energy of great potential value to the power industry in the context of a low carbon society. Rapid development of offshore wind energy depends on a good understanding of technical issues related to offshore wind turbines, which is spurring ongoing research and development programmes. Foundations of offshore wind turbines present one of the main challenges in offshore wind turbine design. This paper reviews the present state of knowledge concerning geotechnical and structural issues affecting foundation types under consideration for the support structures of offshore wind turbines, and provides recommendations for future research and de…
Semiactive control for floating offshore wind turbines subject to aero-hydro dynamic loads
2011
Wind and wave dynamic loads might cause undesirable vibrations that affect the structure integrity and system performance of floating offshore wind turbines. This paper addresses the problem of dynamic load mitigation by using semiactive control techniques with the tuned liquid column dampers placed on the turbine’s tower. The control law is formulated based on the mixed H2/H∞ methods for ensuring the system stability and reliability. Furthermore, the proposed controller only uses output feedback so as to avoid the dependence on the knowledge of the states of the system. Peer Reviewed
Analysis of the maximization of wind turbine energy yield using a continuously variable transmission system
2017
Abstract In this paper, an analytic study of the subject of mechanical power transmission in HAWT wind turbine has been carried out. For the most part, the study analyzes the use of continuously variable transmission (CVT) in order to allow the turbine and the electric generator to couple, allowing in turn, an unremitting transmission ratio adjustment. In low-wind sites, the design criteria suggest an oversizing of the wind turbine in order to generate adequate electrical power even at low wind speed. The proposed solution enhances the space of operating points since it allows the electric generator to release the rotational speed from the turbine one (limited due to structural integrity). …
Steady-state security analysis on the transmission grid for various scenarios of wind generation in Sicily
2009
The proposed paper is part of a research aimed at assessing the impact of wind generation on the transmission grid of Sicily, second among the Italian regions for wind power installed. After describing the current state of wind energy generation in Sicily, the paper reports and comments the results of the steady-state security analysis done for various scenarios of wind penetration. For each scenario (maximum and minimum load conditions), the redistribution of power flows on the transmission network, the voltage profiles at nodes, the analysis of contingencies and losses variations are reported.
Small Wind Technology Diffusion in Suburban Areas of Sicily
2015
Among renewable energy resources, wind energy became more attractive in the last decade. Wind farm installations dramatically increased in areas where climatic conditions, topography, and environment have allowed their development. The installation of wind turbines, usually carried out in remote areas, recently began to cover areas identified by a complex terrain such as urban and suburban zones. Although these new plant choices are characterized by lower productivity, there is increasing interest in wind energy production in both urban and suburban areas. In this work the authors have carried out an energy analysis developed from a sample of small wind turbines available on the market. Thi…
Modeling of a Smart Grid System Using Real Time Data οn Neplan
2013
The Institute for Energy and Transport (IET) is one of the seven institutes of the Joint Research Centre, which is a Directorate-General of the European Commission. IET is based both in Petten, the Netherlands, and Ispra, Italy, and has a multidisciplinary team of around three hundred academic, technical and support staff members. The mission of IET is to provide support to European Union policies in order to ensure sustainable, safe, secure and efficient energy production, distribution and use. The Energy Security Unit (ESU) is part of IET based in Petten and Ispra. A research action set up within this unit is devoted to studies on smart electricity systems (SES) and operates a Smart Grids…
Techno-economic optimum sizing of hybrid renewable energy system
2013
Using off grid hybrid renewable energy systems for rural electrification has become an attractive solution for those areas, where grid electricity is not feasible or cost of the grid extension is relatively large. Hybrid system combines several energy systems together, therefore it can supply high reliable electricity rather than a PV/battery system or a wind/battery system. But the most important thing is that the system should be economically attractive. To achieve both of these features, each of the components in the hybrid system should be optimally sized. This requires a detailed techno-economic analysis of different possible hybrid system configurations. The objective of this study is…
Eletric vehicles impact using renewable energy
2015
In this moment, the principle topics for the modern world are the reduction of environmental pollution and the production of energy from renewable sources (for example photovoltaic system, wind farm, hydroelectric plants, etc.). This particular attention is determined by different reasons, in particular from the Kyoto Protocol, and from different problems as greenhouse effect, acid rain and climate change. The scope of this work is to study, for different years (1997-2013) in Italy, the production of electric energy from renewable and non-renewable. At a later stage, the attention will be on the consumption of the electric energy divided for different sectors. In particular, we study the po…