Search results for " Wind power"
showing 10 items of 55 documents
Leading Edge Erosion of Wind Turbine Blades: Effects of Environmental Parameters on Impact Velocities and Erosion Damage Rate
2021
Abstract Leading edge erosion (LEE) of a wind turbine blade (WTB) is a complex phenomenon that contributes to high operation and maintenance costs. The impact between rain droplets and rotating blades exerts cyclic fatigue stresses on the leading edge — causing progressive material loss and reduced aerodynamic performance. One of the most important parameters for erosion modelling and damage prediction is the relative impact velocity between rain droplets and rotating blade and depends upon the environmental conditions. The environmental condition, in general, could vary for onshore and offshore wind turbines (OWTs) — for instance, the presence of wave-induced loads along with less turbulen…
A comparative study on the dynamic response of three semisubmersible floating offshore wind turbines
2019
Abstract Currently, there is a great interest to globally develop offshore wind energy due to the greenhouse effect and energy crisis. Great efforts have been devoted to develop reliable floating offshore wind energy technology to exploit the wind energy resources in deep seas. This paper presents a comparative study of the dynamic response of three different semisubmersible floating wind turbine structures. All the three platforms support the same 5MW wind turbine. The platforms examined are: a V-shaped Semi, an OC4-DeepCwind Semi and a Braceless Semi at 200 m water depth. A dynamic analysis is carried out in order to calculate and compare the performance of these platforms. The comparison…
Further Results on Modeling, Analysis, and Control Synthesis for Offshore Wind Turbine Systems
2014
Renewable energy is a hot topic all over the world. Nowadays, there are several sustainable renewable power solutions out there; hydro, wind, solar, wave, and biomass to name a few. Most countries have a tendency to want to become greener. In the past, all new wind parks were installed onshore. During the last decade, more and more wind parks were installed offshore, in shallow water. This chapter investigates a comparative study on the modeling, analysis, and control synthesis for the offshore wind turbine systems. More specifically, an \( {\mathcal{H}}_{\infty } \) static output-feedback control design with constrained information is designed. Constrained information indicates that a rema…
Discrete-time static output-feedback H<inf>&#x221E;</inf> controller design for vehicle suspensions
2014
This paper provides a direct and practical presentation of a novel methodology for static output-feedback controller design. The proposed design strategy has been successfully applied in the fields of control systems for seismic protection of large buildings and multi-building structures, control of offshore wind turbines, and active control of vehicle suspensions. The positive results obtained in these initial applications clearly indicate that this approach could be an effective tool in a large variety of control problems, for which an LMI formulation of the statefeedback version of the problem is available. The main objective of the paper is to facilitate a brief and friendly presentatio…
Offshore wind metadata management
2014
Offshore wind energy is gaining more and more attention from industry and research community due to its high potential in producing green energy and lowering price on electricity consumption. However, offshore wind is facing many challenges, and hence it is still expensive to install in large scale. It therefore needs to be considered from different aspects of technologies in order to overcome these challenges. One of the problems of the offshore wind is that information comes from different sources with diversity in types and format. Besides, there are existing wind databases that should be utilised in order to enrich the knowledge base of the wind domain. This paper describes an approach …
Damage identification of a jacket support structure for offshore wind turbines
2020
Offshore jacket structures are regarded as a suitable type of support structure for offshore wind turbines in immediate water depths. Because of the welded tubular members used and environmental conditions, offshore jackets are often subjected to fatigue damages during their service life. Underwater sensors can provide measurements of the structural vibration signals and provide an efficient way to detect damages at early stages. In this work, simplified forms of the damages are assumed, random damages are imposed on the jacket structure, and damaged indicators are established from combination of modal shapes. Then, a response surface is constructed mapping the damage indicators and damages…
Italian incentive strategy and regulations on small wind power turbines: A critical overview
2016
Small wind power industry in Italy had its kick-start in 2009, after the Government implemented two measures introducing both the simplified regime and incentive rates for small wind power plants. In the last six years, a lot of plants and small wind turbines have been installed in Italy, especially in the South. Aim of this paper is to examine how local standards, incentive policy and regulations have affected the spread of small wind turbines in Italy. After examining national and regional legislation, an analysis of the data on the penetration of wind systems in Italy has been carried out, with particular attention to six Southern regions (Basilicata, Calabria, Campania, Apulia, Sardinia…
Numerical study of a concept for major repair and replacement of offshore wind turbine blades
2020
Repair and replacement of offshore wind turbine blades are necessary for current and future offshore wind turbines. To date, repair activities are often conducted using huge jack-up crane vessels and by applying a reverse installation procedure. Because of the high costs associated with installation and removal of offshore wind turbine components and the low profit margin of the offshore wind industry, alternative methods forinstallation and removal are needed. This paper introduces a novel concept for replacement or installation of offshore windturbine blades. The concept involves a medium-sized jack-up crane vessel and a tower climbing mechanism. This mechanism provides a stable platform …
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
A synthesis of feasible control methods for floating offshore wind turbine system dynamics
2021
Abstract During the past decade, the development of offshore wind energy has transitioned from near shore with shallow water to offshore middle-depth water regions. Consequently, the energy conversion technology has shifted from bottom-fixed wind turbines to floating offshore wind turbines. Floating offshore wind turbines are considered more suitable, but their cost is still very high. One of the main reasons for this is that the system dynamics control method is not well-adapted, thereby affecting the performance and reliability of the wind turbine system. The additional motion of the platform tends to compromise the system’s performance in terms of power maximization, power regulation, an…