Room:
Egbert-von-Hoyer Hall
Topic:
D. Control and supporting technologies
Form of presentation:
Oral
Duration:
120 Minutes
Chaired by: J.-W. van Wingerden, E. Bossanyi
10:30
Simultaneous observation of wind shears and misalignments from rotor loads
Marta Bertelè | Technische Universität München | Germany
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Authors:
Marta Bertelè | Technische Universität München | Germany
Carlo L. Bottasso | Germany
Dr. Stefano Cacciola | Germany
A wind turbine is used in this paper as a sensor to measure the wind conditions at the rotor disk. In fact, as any anisotropy in the wind will lead to a specific signature in the machine response, by inverting a response model one may infer its generating cause, i.e. the wind. Control laws that exploit this knowledge can be used to enhance the performance of a wind turbine or a wind power plant. This idea is used in the present paper to formulate a linear implicit model that relates wind states and rotor loads. Simulations are run in both uniform and turbulent winds, using a high-fidelity aeroservoleastic wind turbine model. Results demonstrate the ability of the proposed observer in detecting the horizontal and vertical wind misalignments, as well as the vertical and horizontal shears.
10:50
Gusts detection in a horizontal wind turbine by monitoring of innovations error of an extended Kalman filter
Dr. Luis Recalde | University of Strathclyde | United Kingdom
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Authors:
Dr. Luis Recalde | University of Strathclyde | United Kingdom
Sung-ho Hur | United Kingdom
William Leithead | United Kingdom
This paper presents a novel model-based detection scheme capable of detecting and diagnosing gusts. Detection is achieved by monitoring the innovations error (i.e., the difference between the estimated and measured outputs) of an extended Kalman filter. It is designed to trigger a detection/confirmation alarm in the presence of wind anomalies. Simulations results are presented to demonstrate that both operating and coherent extreme wind gusts can successfully be detected. The wind anomaly is identified in magnitude and shape through maximum likelihood ratio and goodness of fit, respectively. The detector is capable of isolating extreme wind gusts before the turbine over speeds.
11:10
Statistical Evaluation of the Identfied Structural Parameters of an idling Offshore Wind Turbine
Paul Van Der Valk | Netherlands
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Authors:
Hendrik Kramers | Delft University of Technology | Netherlands
Jan-Willem Van Wingerden | Netherlands
Paul Van Der Valk | Netherlands
With the increased need for renewable energy, new offshore wind farms are being developed at an unprecedented scale. However, as the costs of offshore wind energy are still too high, design optimization and new innovations are required for lowering its cost. The design of modern day offshore wind turbines relies on numerical models for estimating ultimate and fatigue loads of the turbines. The dynamic behavior and the resulting structural loading of the turbines is determined for a large part by its structural properties, such as the natural frequencies and damping ratios. Hence, it is important to obtain accurate estimates of these modal properties. For this purpose stochastic subspace identification (SSI), in combination with clustering and statistical evaluation methods, is used to obtain the variance of the identified modal properties of an installed 3.6MW offshore wind turbine in idling conditions. It is found that one is able to obtain confidence intervals for the means of eigenfrequencies and damping ratios of the fore-aft and side-side modes of the wind turbine.
11:30
Diagnostics for Electrically Operated Pitch Systems in Offshore Wind Turbines
Surya Teja Kandukuri | University of Agder | Norway
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Authors:
Surya Teja Kandukuri | University of Agder | Norway
Hamid Reza Karimi | Norway
Kjell Gunnar Robbersmyr | Norway
This paper investigates the electrically operated pitch systems of offshore wind turbines for online condition monitoring and health assessment. The current signature based fault diagnostics is developed for electrically operated pitch systems using model-based approach. The electrical motor faults are firstly modelled based on modified winding function theory and then, current signature analysis is performed to detect the faults. Further, in order to verify the fault diagnostics capabilities in realistic conditions, the operating profiles are obtained from FAST simulation of offshore wind turbines in various wind conditions. In this way, the applicability of current signature analysis for fault diagnostics in offshore wind turbine pitch systems is demonstrated.
11:50
Circulation active flow control on a rounded trailing-edge wind turbine airfoil using plasma actuators
Sophie Baleriola | Université d'Orléans | France
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Authors:
Sophie Baleriola | Université d'Orléans | France
Annie Leroy | France
Stéphane Loyer | France
Philippe Devinant | France
Sandrine Aubrun | France
This experimental study focuses on the implementation via plasma actuators of a circulation control strategy on a wind turbine aerofoil with a rounded trailing-edge with the objective of reducing the aerodynamic load fluctuations on blades. Three sets of multi-DBD (Dielectric Barrier Discharge) actuators with different positions around the trailing-edge are studied. These actuators create a tangential jet that adheres to the blade model wall and diffuses along it. According to the jet direction, lift is increased or decreased. Load and pressure measurements as well as Particle Image Velocimetry (PIV) show respectively the actuation effectiveness in terms of load modification and flow topology alteration.
12:10
On the effects of basic platform design characteristics on floating offshore wind turbine control and their mitigation
Joannes Olondriz | Ikerlan | Spain
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Authors:
Joannes Olondriz | Ikerlan | Spain
Aron Pujana | Spain
Joseba Landaluze | Spain
Igancio Trojaola | Spain
Iker Elorza | Spain
Semi-submersible floating offshore wind turbines present significant advantages over other designs in terms of cost, deployment, maintenance and site-independence. However, these advantages are achieved by shifting a part of the burden of stabilising the platform pitch and roll motions to the turbine control system. A study is presented here of the effects of basic platform dimensions on the performance of a standard pitch controller and the possible methods for mitigating said effects.