Dynamic Analysis of the Wind Turbine Tower

2013 ◽  
Vol 790 ◽  
pp. 651-654
Author(s):  
Chi Chen ◽  
Hong Bo Shen ◽  
Min Wang
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Natural Frequencies ◽  
Safety Evaluation ◽  
Model Analysis ◽  
Rotational Frequency ◽  
Normal Operation ◽  
Transient Dynamic Analysis ◽  
Operation Conditions ◽  
Wind Turbine Tower

In this thesis, the conical tower of domestic popular 1.5MW wind turbine is analyzed in dynamic by using the software ANSYS. The natural frequencies can be extracted from the model analysis results, comparing them with the impeller rotational frequency and determining whether the tower will resonate when the wind turbine under normal operation conditions. Based on the model analysis, the transient dynamic analysis is carried out by inputting the history records of seismic wave acceleration, Both these two analysis can provide the basis for the safety evaluation of the tower.

scholarly journals Vestas V90-3MW Wind Turbine Gearbox Health Assessment Using a Vibration-Based Condition Monitoring System

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
A. Romero ◽  
Y. Lage ◽  
S. Soua ◽  
B. Wang ◽  
T.-H. Gan
Keyword(s):  
Fault Diagnosis ◽  
Wind Turbine ◽  
Condition Monitoring ◽  
Learning Algorithm ◽  
Health Assessment ◽  
Field Trials ◽  
Health Condition ◽  
Normal Operation ◽  
Wind Turbine Gearbox ◽  
Operation Conditions

Reliable monitoring for the early fault diagnosis of gearbox faults is of great concern for the wind industry. This paper presents a novel approach for health condition monitoring (CM) and fault diagnosis in wind turbine gearboxes using vibration analysis. This methodology is based on a machine learning algorithm that generates a baseline for the identification of deviations from the normal operation conditions of the turbine and the intrinsic characteristic-scale decomposition (ICD) method for fault type recognition. Outliers picked up during the baseline stage are decomposed by the ICD method to obtain the product components which reveal the fault information. The new methodology proposed for gear and bearing defect identification was validated by laboratory and field trials, comparing well with the methods reviewed in the literature.

scholarly journals Vibration-Based Damage Assessment in Gravity-Based Wind Turbine Tower under Various Waves

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Cong-Uy Nguyen ◽  
So-Young Lee ◽  
Heon-Tae Kim ◽  
Jeong-Tae Kim
Keyword(s):  
Wind Turbine ◽  
Damage Assessment ◽  
Natural Frequencies ◽  
Modal Identification ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Damage Scenarios ◽  
Wind Turbine Tower ◽  
Induced Variation ◽  
Wave Induced

In this study, the feasibility of vibration-based damage assessment in a wind turbine tower (WTT) with gravity-based foundation (GBF) under various waves is numerically investigated. Firstly, a finite element model is constructed for the GBF WTT which consists of a tower, caisson, and foundation bed. Eigenvalue analysis is performed to identify a few vibration modes of interest, which represent complex behaviors of a flexible tower, rigid caisson, and deformable foundation. Secondly, wave-induced dynamic pressures are analyzed for a few selected wave conditions and damage scenarios are also designed to simulate the main components of the target GBF WTT. Thirdly, forced vibration responses of the GBF WTT are analyzed for the wave-induced excitation. Then modal parameters (i.e., natural frequencies and mode shapes) are extracted by using a combined use of time-domain and frequency-domain modal identification methods. Finally, the variation of modal parameters is estimated by measuring relative changes in natural frequencies and mode shapes in order to quantify the damage-induced effects. Also, the wave-induced variation of modal parameters is estimated to relatively assess the effect of various wave actions on the damage-induced variation of modal parameters.

Vibrations of a Three-Bladed Wind Turbine Rotor Due to Classical Flutter

2002 ◽  
Author(s):  
M. H. Hansen
Keyword(s):  
Wind Turbine ◽  
Critical Frequency ◽  
Turbine Blades ◽  
Turbine Rotor ◽  
Normal Operation ◽  
Aerodynamic Damping ◽  
Operation Conditions ◽  
Torsional Frequency ◽  
Classical Flutter ◽  
Wind Turbine Rotor

The aeroelastic stability of a three-bladed wind turbine is considered with respect to classical flutter. Previous studies have shown that the risk of stall-induced vibrations of turbine blades is related to the dynamics of the complete turbine, for example does the aerodynamic damping of a rotor whirling mode depend highly on the tower stiffness. The results of this paper indicate that the turbine dynamics also affect the risk of flutter. The study is based on an eigenvalue analysis of a linear aeroelastic turbine model. In an example of a MW sized turbine, the critical frequency of the first torsional blade mode is determined for which flutter can occur under normal operation conditions. It is shown that this critical torsional frequency is higher when the blades are interacting through the hub with the remaining turbine, than when all blades are rigidly clamped at the root. Thus, the dynamics of the turbine has increased the risk of flutter.

The Finite Element Analysis and Comparison of Wind Turbine Tower under Static Wind Load and Fluctuating Wind Load

2013 ◽  
Vol 446-447 ◽  
pp. 733-737
Author(s):  
Chi Chen ◽  
Hao Yuan Chen ◽  
Tian Lu
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Wind Turbine ◽  
Modal Analysis ◽  
Large Scale ◽  
Wind Load ◽  
Element Analysis ◽  
Finite Element Software ◽  
Wind Turbine Tower ◽  
Fluctuating Wind

In this paper, a 1.5 MW wind turbine tower in Dali, Yunnan Province is used as the research object, using large-scale finite element software Ansys to carry on the dynamic analysis. These natural frequencies and natural vibration type of the first five of tower are obtained by modal analysis and are compared with natural frequency to determine whether the resonance occurs. Based on the modal analysis, the results of the transient dynamic analysis are obtained from the tower, which is loaded by the static wind load and fluctuating wind load in two different forms. By comparing the different results, it provides the basis for the dynamic design of wind turbine tower.

Assessing the Importance of Geometric Nonlinear Effects in the Prediction of Wind Turbine Blade Loads

2015 ◽  
Vol 10 (4) ◽  
Author(s):  
D. I. Manolas ◽  
V. A. Riziotis ◽  
S. G. Voutsinas
Keyword(s):  
Wind Turbine ◽  
Nonlinear Effects ◽  
Normal Operation ◽  
Order Model ◽  
Multibody Model ◽  
Operation Conditions ◽  
Geometric Nonlinear ◽  
Structural Nonlinearities ◽  
Clear Shift ◽  
Blade Loads

As the size of commercial wind turbines increases, new blade designs become more flexible in order to comply with the requirement for reduced weights. In normal operation conditions, flexible blades undergo large bending deflections, which exceed 10% of their radius, while significant torsion angles toward the tip of the blade are obtained, which potentially affect performance and stability. In the present paper, the effects on the loads of a wind turbine from structural nonlinearities induced by large deflections of the blades are assessed, based on simulations carried out for the NREL 5 MW wind turbine. Two nonlinear beam models, a second order (2nd order) model and a multibody model that both account for geometric nonlinear structural effects, are compared to a first order beam (1st order) model. Deflections and loads produced by finite element method based aero-elastic simulations using these three models show that the bending–torsion coupling is the main nonlinear effect that drives differences on loads. The main effect on fatigue loads is the over 100% increase of the torsion moment, having obvious implications on the design of the pitch bearings. In addition, nonlinearity leads to a clear shift in the frequencies of the second edgewise modes.

Structural Dynamics and Load Analysis of Large Offshore Wind Turbines in Western Gulf of Mexico Shallow Water

2014 ◽  
Author(s):  
Ling Ling Yin ◽  
King Him Lo ◽  
Su Su Wang
Keyword(s):  
Gulf Of Mexico ◽  
Wind Turbine ◽  
Shallow Water ◽  
Structural Dynamics ◽  
Natural Frequencies ◽  
Offshore Wind ◽  
Normal Operation ◽  
Mode Shapes ◽  
Offshore Wind Turbine ◽  
Support Structure

In this paper, a study is conducted on wind and metocean loads and associated structural dynamics of a 13.2-MW large offshore wind turbine in Western Gulf of Mexico (GOM) shallow water. The offshore wind turbine considered includes a rotor with three 100-meter long blades and a mono-tower support structure. Natural frequencies and mode shapes of the blades and the mono-tower are determined first and used subsequently to establish a Campbell diagram for safe wind turbine operation. The results show that hydrodynamic added mass has little effect on the natural frequencies and mode shapes of the support structure but it introduces, in part, appreciable effects on loads carried by the turbine when the blades are pitched at wind speeds above the rated speed. Also determined, for normal operation and extreme metocean conditions (i.e., 100-year return hurricanes), are normal thrust on the wind rotor, blade-tip displacement, overturning moment and tower-top displacement sustained by the wind turbine.

scholarly journals Adaptive Machine Learning Approach for Fault Prognostics based on Normal Conditions - Application to Shaft Bearings of Wind Turbine

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Koceila Abid ◽  
Moamar Sayed-Mouchaweh ◽  
Cornez Laurence
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Remaining Useful Life ◽  
Normal Operation ◽  
Maintenance Cost ◽  
Support Vector ◽  
Industrial Systems ◽  
Operation Conditions ◽  
Degradation Data ◽  
Fault Prognostics

Prognostics can enhance the reliability and availability of industrial systems while reducing unscheduled faults and maintenance cost. In real industrial systems, data collected from the normal operation conditions of system is available, but there is a lack of historical degradation data is often unavailable. Hence, this paper proposes a general data-driven prognostic approach dealing with the lack of degradation data in the offline phase. First, features are computed on the collected raw signal, then One Class Support Vector Machine (OCSVM) is used to detect the degradation, this anomaly detection method is trained using only normal operation data. Then, features are ranked according to the selection criteria. The feature having the highest score is chosen as Health Indicator (HI). Finally an adaptive degradation model is applied for the prediction of the degradation evolution over time and Remaining Useful Life (RUL) estimation. The proposed approach is validated using run-to-failure vibration data collected from a high speed shaft bearings of a commercial wind turbine.

Vibration Characteristics Analysis of Wind Turbine Towers under Foundation Conditions

2013 ◽  
Vol 446-447 ◽  
pp. 721-727
Author(s):  
Xi Song ◽  
Yin Guang Wu ◽  
Jie Yu Li ◽  
Rong Zhen Zhao
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Natural Frequency ◽  
Large Scale ◽  
Horizontal Axis Wind Turbine ◽  
Static And Dynamic Analysis ◽  
Wind Turbine Tower ◽  
Characteristics Analysis ◽  
Wind Turbine Towers ◽  
Tower Foundation

Based on a kind of 1.5MW large-scale horizontal axis wind turbine tower, the mechanical modeling of a wind turbine tower-foundation is established, the static and dynamic analysis of the model is carried out by ANSYS software. The top displacement of the system is calculated by the static analysis to meet the design requirements in engineering. In dynamic analysis, each pile foundation is equivalent to a group of springs for the simulation of horizontal and vertical rigidity of the pile. The influence of top mass and foundation elasticity on wind turbine tower modes is analyzed, and calculated the natural frequency of the tower within a certain scope of rigidity in different directions about the piles foundation. The results show that the natural frequency of the wind turbine tower is influenced significantly by the mass on the tower top and foundation rigidity. The study provides a theoretical basis for optimal design of the wind turbine.

Finite Element Analysis of Concrete Filled Double Skin Steel Tubes for Wind Turbine Tower

2014 ◽  
Vol 680 ◽  
pp. 551-556
Author(s):  
Wei Kong ◽  
Hong Liang Wang ◽  
Ying Cai
Keyword(s):  
Finite Element ◽  
Wind Speed ◽  
Wind Turbine ◽  
Normal Operation ◽  
Mode Shapes ◽  
Strength Analysis ◽  
Element Analysis ◽  
Finite Element Software ◽  
Wind Turbine Tower ◽  
Double Skin

In order to save the steel consumption,ensure the better economy of wind turbine tower,this paper designeda new concrete filled double skin steel tube for wind turbine tower,based on the parameters of 1. 5 MW wind turbine tower.A three-dimensional finite element model of wind turbine tower was built by using the finite element software ANSYS,then the static strength analysis and modal analysis were carried out,in which the stress and displacement at the top of the tower were calculated under three kinds of working conditions: normal operation with rated wind speed,normal operation with cutout wind speed and shutdown under extreme wind conditions,the natural frequency and mode shapes of the tower were obtained as well. The results show that the tower does not resonate with blades,and its structure can meet the strength and stiffness requirements of engineering.

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