The Proportional Integral Notch and Coleman Blade Effective Wind Speed Estimators and Their Similarities

The estimation of the rotor effective wind speed is used in modern wind turbines to provide advanced power and load control capabilities. However, with the ever increasing rotor sizes, the wind field over the rotor surface shows a higher degree of spatial variation. A single effective wind speed estimation therefore limits the attainable...

The Immersion and Invariance Wind Speed Estimator Revisited and New Results

The Immersion and Invariance (II) wind speed estimator is a powerful and widely-used technique to estimate the rotor effective wind speed on horizontal axis wind turbines. Anyway, its global convergence proof is rather cumbersome, which hinders the extension of the method and proof to time-delayed and/or uncertain systems. In this letter, we...

Periodic Load Estimation of a Wind Turbine Tower using a Model Demodulation Transformation

The ever-increasing power capacities of wind turbines promote the use of tall and slender turbine towers. This poses a challenge from a fatigue loading perspective by the relocation of the first and lightly-damped tower side-side natural frequency into the turbine operating regime, promoting its excitation during nominal operation. The...

An Economic Model Predictive Control Approach for Load Mitigation on Multiple Tower Locations of Wind Turbines

The current trend in the evolution of wind turbines is to increase their rotor size in order to capture more power. This leads to taller, slender and more flexible towers, which thus experience higher dynamical loads due to the turbine rotation and environmental factors. It is hence compelling to deploy advanced control methods that can...

Convex Model Predictive Control for Down-regulation Strategies in Wind Turbines

Wind turbine (WT) controllers are often geared towards maximum power extraction, while suitable operating constraints should be guaranteed such that WT components are protected from failures. Control strategies can be also devised to reduce the generated power, for instance to track a power reference provided by the grid operator. They are...

3D FE-Informed Laboratory Soil Testing for the Design of Offshore Wind Turbine Monopiles

Based on advanced 3D finite element modelling, this paper analyses the stress paths experienced by soil elements in the vicinity of a monopile foundation for offshore wind turbines subjected to cyclic loading with the aim of informing soil laboratory testing in support of monopile foundation design. It is shown that the soil elements in front of...

Controlling dynamic stall using vortex generators on a wind turbine airfoil

Vortex generators (VGs) have proven their capabilities in wind turbine applications to delay stall in steady flow conditions. However, their behaviour in unsteady conditions is insufficiently understood. This paper presents an experimental study that demonstrates the effect of VGs in unsteady flow, including controlling and suppressing the...

Technical potential of on-site wind powered hydrogen producing refuelling stations in the Netherlands

This study assesses the technical potential of wind turbines to be installed next to existing fuelling stations in order to produce hydrogen. Hydrogen will be used for Fuel Cell Vehicle refuelling and feed-in existing local gas grids. The suitable fuelling stations are selected through a GIS assessment applying buffer zones and taking into...

Lifetime comparison of power semiconductors in three-level converters for 10MW wind turbine systems

The power electronic converter, especially the power semiconductor, is a major contributor to the failure rates of the wind turbine drivetrain. As the temperature is a major driving factor behind the failure mechanisms of these power semiconductors the choice of topology and switching strategy can have a significant effect on the reliability...

Radar micro-Doppler of Wind Turbines: Low-Frequency Polarimetric Extension of Simplified Analytical Model

A simplified polarimetric model for radar signal scattering on wind turbines (WT) is proposed, which can be used for interpretation of observation in time and Doppler domains. This model uses representation of real WT as slowly rotating linear wire structures. The earlier proposed model has been extended to more general cases of WT with...

The Smart Rotor Concept on Wind Turbines - Actuators and Structures

Wind turbines suffer heavily from fatigue loads but current load control concepts are not effective in mitigating them. This thesis contributes to the development of a novel concept in which the air flow over the blade is controlled through spanwise distributed devices. The work is aimed at implementing adaptive materials, such as shape memory...

Optimization of the maintenance scheduling and production valuation by green certificates

Summary Part I - Optimization of the maintenance scheduling Resource management in the industry is an important feature to make the most of the production, particularly in maintenance field where the availability of people is a very important condition to minimize losses. An optimized maintenance scheduling is of a crucial importance for wind...

WISPER and WISPERX Final definition of two standardised fatigue loading sequences for wind turbine blades

WISPER and WISPERX are standardised variable-amplitude test loading histories for use in the fatigue design of horizontal axis wind turbine blades. They are based on flap load service measurements on 9 different horizontal axis wind turbines, covering a wide range of materials, rotor diameters and geographical locations. The present report is...