Wind power has expanded significantly over the past years, although reliability of wind turbine systems, especially of offshore wind turbines, has been many times unsatisfactory in the past. Wind turbine failures are equivalent to crucial financial losses. Therefore, creating and applying strategies that improve the reliability of their components is important for a successful implementation of...

Preface This final report for IEA Wind Task 23, Offshore Wind Energy Technology and Deployment, is made up of two separate reports, Subtask 1: Experience with Critical Deployment Issues and Subtask 2: Offshore Code Comparison Collaborative (OC3). Subtask 1 discusses ecological issues and regulation, electrical system integration, external conditions, and key conclusions for Subtask 1. Subtask 2...

This paper presents the stability enhancement of four parallel-operated offshore Wind Turbine Generators (WTGs) is connected to an onshore power system using a Static Synchronous Compensator (STATCOM). The operating characteristics of each of the four WTGs are simulated by wind permanent magnet synchronous generator while the onshore power system is simulated by a Synchronous Generator (SG) fed...

The development is presented of two low weight, motion resistant stiff floating wind turbine concepts for deployment in water depths ranging from 30 to several hundred meters in seastates with wave heights up to 30 meters supporting 3-5 MW onshore wind turbines. The floating wind turbines may be fully assembled at a coastal facility in their upright position prior to being towed to the offshore...

Severe foundation scour may occur around monopile foundations of offshore wind turbines due to currents and waves. The so-called p-y curves method is suggested in the existing design recommendations to determine the behavior of monopiles unprotected against scour and the reduction of effective soil stress is accounted for by the extreme scour depth. This conservative design approach does not co...

Offshore wind power production is an attractive clean energy option, but the difficulty of access can lead to expensive and rare opportunities for maintenance. As part of the Structural Health and Prognostics Management (SHPM) project at Sandia National Laboratories, smart loads management (controls) are investigated for their potential to increase the fatigue life of offshore wind turbine roto...

In evaluating ultimate limit states for design, time-domain aeroelastic response simulations are typically carried out to establish extreme loads on offshore wind turbines. Accurate load prediction depends on proper modeling of the wind turbulence and the wave stochastic processes as well as of the turbine, the support structure, and the foundation. One method for modeling the support structure...

ccess to an offshore wind turbine is greatly limited by the environment; consequently operation and maintenance (O&M) can become more sporadic and infrequent. This reduces the turbine availability, thus decreasing the generated output [1]. O&M is already a large part of the life costs of a turbine, but with offshore turbines, this will increase greatly with the inclusion of vessel hire costs [2...

The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be possible to combine damage tolerant structural design, monitoring systems, inspection techniques a...