Modal analysis of an operational offshore wind turbine using enhanced Kalman filter-based subspace identification

Operational modal analysis (OMA) is an essential tool for understanding the structural dynamics of offshore wind turbines (OWTs). However, the classical OMA algorithms require the excitation of the structure to be stationary white noise, which is often not the case for operational OWTs due to the presence of periodic excitation caused by...

Editorial: Noise and vibrations in offshore wind farms and their impact on aquatic species

Development of clustering strategy to optimize the design of RNA and support structure in offshore wind farm under seismic conditions

Offshore wind energy is one of the emerging renewable technologies toward a zero-carbon emission society. Historically, offshore wind farms have been developed in the North Sea, but nowadays wind farms are expanded to other regions such as North America and Asia, which are seismic prone.<br/>In the design of Rotor-Nacelle-Assembly (RNA) and...

A 2D test setup for scaled real-time hybrid tests of dynamic ice-structure interaction

With the ongoing development of offshore wind in cold regions where the foundations are exposed to sea ice, there is a strong need for data to validate the numerically predicted dynamic interaction between ice and structure used for design. Full-scale data is non-existent and only a limited number of experimental campaigns in ice tanks have been...

Floating blade installation: Analysing the dynamic interaction between tower and installation tool

The demand for blade installation and maintenance is increasing with each additional installed offshore wind turbine. In 2017, 560 additional turbines were installed in Europe, reaching 4149 turbines in total. Currently, they are serviced with cost and time inefficient methods, such as rope access and jack-up vessels. Rope access is slow and...

Machine learning techniques for load monitoring of offshore wind turbines

In the race for cost reduction in the offshore wind industry, support structure optimization leading to weight reduction plays a prominent role. The fatigue limit state is often the driving consideration for support structure design. Monitoring the monopile loads can offer an accurate knowledge of its consumed and remaining fatigue lifetime,...

Geotechnical Aspects of Offshore Wind Turbine Dynamics Emerging from 3d Sand-Monopile Non-Linear Simulations

In recent years, offshore wind is becoming an increasingly growing market in Europe. Many resources are allocated towards ensuring its sustainable progress while one of the biggest uncertainties encountered lays in the offshore wind turbine's (OWT) foundations. In Europe, monopiles are the most widely adopted solution to found such structures in...

Damping Identification of an Offshore Wind Turbine: A Predictor-Based Subspace Identification Approach

Increasing the capacity of offshore wind energy is a necessary step in the transition from fossil fuels to renewable energy sources. In order to accelerate this process, the costs of wind energy should be reduced to make it more competitive with traditional energy sources. Cost reduction could be achieved by increasing the lifetime of an...

Support Structure Optimization: On the use of load estimations for time efficient optimization of monopile support structures of offshore wind turbines

Over the years, the installed capacity of offshore wind turbines is increasing rapidly. However, the Levelized Costs Of Energy (LCOE) is still higher than the LCOE of traditional energy production methods like nuclear power or energy from coals or gas. This research focuses on a further decrease of the LCOE, by minimizing the mass of a monopile...

Role of advanced soil modelling in the dynamic analysis of offshore wind turbines

The increasing relevance of offshore wind in the energy mix motivates continual research efforts for the optimisation of foundation systems. Currently, monopiles are still the most common foundations for offshore wind turbines (OWTs), due to their simplicity and the low costs for production/assembly. However, the modern trends towards larger...

Seismic Inversion for Identification of Soil Stiffness and Damping for Offshore Wind Turbines

Non-invasive in-situ measurements can determine the soil properties in an undisturbed way, providing a more accurate characterization of the soil stiffness and damping. This report focuses on the multichannel analysis of surface waves (MASW) technique. The measured dispersion of a propagating seismic wave is used to characterize the variation of...

Gravity Based Foundation: Scour and design optimisation

Within Royal HaskoningDHV an innovative concept is thought to be feasible as a new foundation for larger wind turbines in deeper waters. In this thesis the development of this innovative offshore wind turbine foundation was aided. The research focused on two topics: - Scour at this gravity based foundations. - Possible design optimisations with...

Vibration-based Identification of Hydrodynamic Loads and System Parameters for Offshore Wind Turbine Support Structures

For reliable structural health monitoring and possible lifetime extension of offshore wind turbine support structures, accurate predictions of the response of these structures at all critical locations are required. Response predictions in offshore wind applications are, however, affected by large uncertainties on environmental (wind/wave...

Ecology-based bed protection of offshore wind turbines

The offshore wind industry is a growing market in Europe due to the sustainable energy targets of European Union. In the coming years the Dutch government will invest in offshore wind farms at the North Sea. For a contractor like Boskalis the inclusion of favorable ecological conditions in designs is a unique selling point and can help to win...

Hydrodynamic loading on the shaft of a gravity based offshore wind turbine

Gravity based support structure By a joint venture of BAM and Van Oord an innovative type of Gravity Based Structure (GBS) for an offshore wind turbine was developed. The GBS consist of a concrete caisson and a steel shaft. The applicable water depth range is between 35 and 60m. Hydrodynamic loading on the shaft In order to optimize the support...

Design study of a 10 MW MgB2 superconductor direct drive wind turbine generator

A superconducting direct drive generator based on field windings of MgB2 superconducting tape is proposed as a solution by mounting the generator in front of the blades using a king-pin nacelle design for offshore turbines with power ratings larger than 10 MW as investigated in the INNWIND.EU project.

Edge scour around an offshore wind turbine

Wind energy has experienced an enormous growth in the last years and is becoming more and more popular as an alternative for conventional power. Large growth numbers are also expected for the coming years, for onshore as well as for offshore wind energy. Currently, a wind power capacity of almost 4 GW is installed offshore in the European Union,...

Lattice Tower Design of Offshore Wind Turbine Support Structures

Optimal design of support structure including foundation and turbine tower is among the most critical challenges for offshore wind turbine. With development of offshore wind industry heading for deeper ocean areas, new support structural concept such as a full lattice tower could be proven to be more advantageous than others when consideration...