Nowadays, propagation of wind turbines make challenges to supply safe power to the grid. Because of wind speed changes, supervisors are concerned to wind turbines, be able to produce appropriate electric power during the wind speed changes. As a matter of fact, investors are mostly like to invest on offshore wind farms, because of their more stable and continuous wind speed rather than onshore ...

FAST, developed by the National Renewable Energy Laboratory, is a computer-aided engineering tool for aero-hydro-servo-elastic analysis of land-based and offshore wind turbines. This paper discusses the development of a new module (SubDyn), which when integrated to FAST, will enable loads simulations of offshore wind turbines with fixed-bottom, multimember support structures. The main theory an...

Wind turbines can be considered as structures that are in between civil engineering structures and machines since they consist of structural components and many electrical and machine components together with a control system. Further, a wind turbine is not a one-of-a-kind structure but manufactured in series production based on many component tests, some prototype tests and zeroseries wind tur...

Condition monitoring (CM) systems are increasingly installed in wind turbines with the goal of providing component-specific information to wind farm operators, theoretically increasing equipment availability via maintenance and operating actions based on this information. In the offshore case, economic benefits of CM systems are often assumed to be substantial, as compared with experience of on...

Offshore wind turbine technology is moving forward as a cleaner alternative to the fossil fuelled power production. However, there are a number of challenges in offshore; wind turbines are subject to different loads that are not often experienced onshore and more importantly challenging wind and wave conditions limit the operability of the vessels needed to access offshore wind farms. As the po...

This paper presents a procedure for wind farm model simulation. The simulation model serves as a benchmark for controller development and verification in the EU-FP7 project Aeolus. A generic dynamic flow modeling relates single turbine production and fatigue load to the map of wind speeds. The model integrates the wind farm aerodynamics to the dynamics of individual turbines by means of wake me...

An important implementation issue for wind farms is the risk of bird collision. A lot of the existing knowledge on birds and wind energy is based on studies at onshore sites. With respect to wind energy implementation especially offshore, more information about the environmental impact is needed. Several countries carrying out environmental base line studies focuses on offshore wind farm sites....

One of the critical design driving load cases for modern large onshore/offshore wind turbines is power production in extreme turbulence. According to the IEC 61400-1 edition 3 design standard, the normal production extreme loads are extrapolated and compared to the extreme loads obtained under extreme turbulence input. This study shows that using a probabilistic approach and the first order rel...

This paper focuses on the wind energy conversion system (WECS) with the three main electrical aspects: 1) wind turbine generators (WTGs), 2) power electronics converters (PECs) and 3) grid-connection issues. The current state of wind turbine generators are discussed and compared in some criteria along with the trends in the current WECS market, which are ‘Variable Speed’, ‘Multi-MW’ and ‘Offsho...

A Markov model for the performance of wind turbines is developed that accounts for component reliability and the effect of wind speed and turbine capacity on component reliability. The model is calibrated to the observed performance of offshore turbines in the north of Europe, and uses wind records obtained from the coast of the state of Maine in the northeast United States in simulation. Simul...