Adaptive bidirectional dynamic response control of offshore wind turbines with time‐varying structural properties

2021 ◽  
Author(s):  
C. Sun ◽  
V. Jahangiri ◽  
H. Sun
Keyword(s):  
Dynamic Response ◽  
Structural Properties ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Time Varying ◽  
Response Control ◽  
Offshore Wind Turbines

scholarly journals A Surface Ice Module for Wind Turbine Dynamic Response Simulation Using FAST

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Bingbin Yu ◽  
Dale G. Karr ◽  
Huimin Song ◽  
Senu Sirnivas
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Structural Response ◽  
Simulation Software ◽  
Offshore Wind ◽  
Foundation Soil ◽  
Offshore Wind Turbines ◽  
Ice Failure ◽  
Lock In

Developing offshore wind energy has become more and more serious worldwide in recent years. Many of the promising offshore wind farm locations are in cold regions that may have ice cover during wintertime. The challenge of possible ice loads on offshore wind turbines raises the demand of modeling capacity of dynamic wind turbine response under the joint action of ice, wind, wave, and current. The simulation software FAST is an open source computer-aided engineering (CAE) package maintained by the National Renewable Energy Laboratory. In this paper, a new module of FAST for assessing the dynamic response of offshore wind turbines subjected to ice forcing is presented. In the ice module, several models are presented which involve both prescribed forcing and coupled response. For conditions in which the ice forcing is essentially decoupled from the structural response, ice forces are established from existing models for brittle and ductile ice failure. For conditions in which the ice failure and the structural response are coupled, such as lock-in conditions, a rate-dependent ice model is described, which is developed in conjunction with a new modularization framework for FAST. In this paper, analytical ice mechanics models are presented that incorporate ice floe forcing, deformation, and failure. For lower speeds, forces slowly build until the ice strength is reached and ice fails resulting in a quasi-static condition. For intermediate speeds, the ice failure can be coupled with the structural response and resulting in coinciding periods of the ice failure and the structural response. A third regime occurs at high speeds of encounter in which brittle fracturing of the ice feature occurs in a random pattern, which results in a random vibration excitation of the structure. An example wind turbine response is simulated under ice loading of each of the presented models. This module adds to FAST the capabilities for analyzing the response of wind turbines subjected to forces resulting from ice impact on the turbine support structure. The conditions considered in this module are specifically addressed in the International Organization for Standardization (ISO) standard 19906:2010 for arctic offshore structures design consideration. Special consideration of lock-in vibrations is required due to the detrimental effects of such response with regard to fatigue and foundation/soil response. The use of FAST for transient, time domain simulation with the new ice module is well suited for such analyses.

Dynamic response in frequency and time domains of a floating foundation for offshore wind turbines

2013 ◽  
Vol 60 ◽  
pp. 115-123 ◽  
Author(s):  
Ruoyu Zhang ◽  
Yougang Tang ◽  
Jun Hu ◽  
Shengfu Ruan ◽  
Chaohe Chen
Keyword(s):  
Dynamic Response ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Floating Foundation ◽  
Time Domains

Model Tests on the Long-Term Dynamic Performance of Offshore Wind Turbines Founded on Monopiles in Sand

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Zhen Guo ◽  
Luqing Yu ◽  
Lizhong Wang ◽  
S. Bhattacharya ◽  
G. Nikitas ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wind Turbines ◽  
Model Tests ◽  
Offshore Wind ◽  
Frequency Change ◽  
Test Results ◽  
Scaled Model ◽  
Structural Dynamic ◽  
Offshore Wind Turbines

The dynamic response of the supporting structure is critical for the in-service stability and safety of offshore wind turbines (OWTs). The aim of this paper is to first illustrate the complexity of environmental loads acting on an OWT and reveal the significance of its structural dynamic response for the OWT safety. Second, it is aimed to investigate the long-term performance of the OWT founded on a monopile in dense sand. Therefore, a series of well-scaled model tests have been carried out, in which an innovative balance gear system was proposed and used to apply different types of dynamic loadings on a model OWT. Test results indicated that the natural frequency of the OWT in sand would increase as the number of applied cyclic loading went up, but the increasing rate of the frequency gradually decreases with the strain accumulation of soil around the monopile. This kind of the frequency change of OWT is thought to be dependent on the way how the OWT is cyclically loaded and the shear strain level of soil in the area adjacent to the pile foundation. In this paper, all test results were plotted in a nondimensional manner in order to be scaled up to predict the consequences for prototype OWT in sandy seabed.

Sensitivity of the Dynamic Response of Monopile-Supported Offshore Wind Turbines to Structural and Foundation Damping

2015 ◽  
Vol 39 (6) ◽  
pp. 609-627 ◽  
Author(s):  
Casey M. Fontana ◽  
Wystan Carswell ◽  
Sanjay R. Arwade ◽  
Don J. DeGroot ◽  
Andrew T. Myers
Keyword(s):  
Dynamic Response ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Offshore Wind Turbines

Soil–Structure–Wave Interaction of Gravity-Based Offshore Wind Turbines: An Analytical Model

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Dimitrios G. Pavlou
Keyword(s):  
Dynamic Response ◽  
Analytical Model ◽  
Wind Turbines ◽  
Initial Conditions ◽  
Offshore Wind ◽  
Design Parameters ◽  
Wave Loads ◽  
Wave Load ◽  
Offshore Wind Turbines ◽  
Dynamic Phenomena

Abstract The structural design of offshore wind turbines is based on the consideration of coupled dynamic phenomena. Wave loads cause the dynamic oscillation of the monopile, and the dynamic oscillation of the monopile affects the wave loads. The boundary conditions of the gravity-based foundation-monopile-turbine system are mostly affected by the flexural stiffness of the foundation plate, the elastic and creep behavior of the soil, and the inertia (translational and rotational) of the wind turbine mass. The design of the foundation should consider the dynamic response of the soil and the monopile, and the dynamic response of the soil and the monopile is affected by the design parameters of the foundation. The initial conditions of the system yield transient dynamic phenomena. A braking wave at t = 0 causes different dynamic response than the steady-state conditions due to a harmonic wave load. In the present work, an integrated analytical model simulating the above dynamic phenomena is proposed. With the aid of double integral transforms and generalized function properties, a solution of the corresponding differential equations for the monopile-soil-foundation system and the boundary and initial conditions is derived. A parametric study is carried out, and results of the effect of the design parameters and soil properties are presented and discussed.

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