Dynamic Load Response Analysis on Yaw Bearing of Wind Turbine to Turbulent Wind

2019 ◽  
Author(s):  
Jianwen Xu
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Gumbel Distribution ◽  
Operating Conditions ◽  
Likelihood Method ◽  
Coupled Analysis ◽  
Response Analysis ◽  
Turbulent Wind ◽  
Load Response ◽  
Yaw Bearing

Abstract Wind turbines are subjected to dynamic loads during their service life. The yaw bearing is an important part which also bears these loads. In this study, a series of 5-megawatt (MW) wind turbines are analyzed for their dynamic response under normal operating conditions while exposed to turbulent wind. These models are Onshore, Monopile, ITI Barge, Spar, Tension-Leg Platform (TLP), Semi-Submerisible. TurbSim is used to prescribe turbulent-wind inflow and a time domain FAST code is applied in order to conduct the Aero-Hydro-Servo-Elastic coupled analysis on the yaw loads of the wind turbines. Three different average wind velocities are examined to compare the load response of the wind turbine to turbulent wind on the yaw bearing. A Gumbel distribution coupled maximum likelihood method is used to predict ultimate loads. And the rain flow counting algorithm, the linear cumulative damage law and S-N curve theory are used to predict the damage equivalent load. The results should aid the fatigue design of yaw bearing and the yaw control system according to different wind turbine design.

scholarly journals Monitoring Wind Turbine Gearbox with Echo State Network Modeling and Dynamic Threshold Using SCADA Vibration Data

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 982 ◽  
Author(s):  
Xin Wu ◽  
Hong Wang ◽  
Guoqian Jiang ◽  
Ping Xie ◽  
Xiaoli Li
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Operating Conditions ◽  
Dynamic Threshold ◽  
Detection Accuracy ◽  
Echo State Network ◽  
Monitoring Method ◽  
Vibration Data ◽  
Static Monitoring ◽  
Threshold Monitoring

Health monitoring of wind turbine gearboxes has gained considerable attention as wind turbines become larger in size and move to more inaccessible locations. To improve the reliability, extend the lifetime of the turbines, and reduce the operation and maintenance cost caused by the gearbox faults, data-driven condition motoring techniques have been widely investigated, where various sensor monitoring data (such as power, temperature, and pressure, etc.) have been modeled and analyzed. However, wind turbines often work in complex and dynamic operating conditions, such as variable speeds and loads, thus the traditional static monitoring method relying on a certain fixed threshold will lead to unsatisfactory monitoring performance, typically high false alarms and missed detections. To address this issue, this paper proposes a reliable monitoring model for wind turbine gearboxes based on echo state network (ESN) modeling and the dynamic threshold scheme, with a focus on supervisory control and data acquisition (SCADA) vibration data. The aim of the proposed approach is to build the turbine normal behavior model only using normal SCADA vibration data, and then to analyze the unseen SCADA vibration data to detect potential faults based on the model residual evaluation and the dynamic threshold setting. To better capture temporal information inherent in monitored sensor data, the echo state network (ESN) is used to model the complex vibration data due to its simple and fast training ability and powerful learning capability. Additionally, a dynamic threshold monitoring scheme with a sliding window technique is designed to determine dynamic control limits to address the issue of the low detection accuracy and poor adaptability caused by the traditional static monitoring methods. The effectiveness of the proposed monitoring method is verified using the collected SCADA vibration data from a wind farm located at Inner Mongolia in China. The results demonstrated that the proposed method can achieve improved detection accuracy and reliability compared with the traditional static threshold monitoring method.

scholarly journals Prognostics-based adaptive control strategy for lifetime control of wind turbines

2021 ◽  
Author(s):  
Edwin Kipchirchir ◽  
Manh Hung Do ◽  
Jackson Githu Njiri ◽  
Dirk Söffker
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Control Strategy ◽  
Fatigue Loading ◽  
Operational Reliability ◽  
Operating Conditions ◽  
Rotor Blades ◽  
Time Step ◽  
Damage Level ◽  
Structural Loading

Abstract. Variability of wind profiles in both space and time is responsible for fatigue loading in wind turbine components. Advanced control methods for mitigating structural loading in these components have been proposed in previous works. These also incorporate other objectives like speed and power regulation for above-rated wind speed operation. In recent years, lifetime control and extension strategies have been proposed to guaranty power supply and operational reliability of wind turbines. These control strategies typically rely on a fatigue load evaluation criteria to determine the consumed lifetime of these components, subsequently varying the control set-point to guaranty a desired lifetime of the components. Most of these methods focus on controlling the lifetime of specific structural components of a wind turbine, typically the rotor blade or tower. Additionally, controllers are often designed to be valid about specific operating points, hence exhibit deteriorating performance in varying operating conditions. Therefore, they are not able to guaranty a desired lifetime in varying wind conditions. In this paper an adaptive lifetime control strategy is proposed for controlled ageing of rotor blades to guaranty a desired lifetime, while considering damage accumulation level in the tower. The method relies on an online structural health monitoring system to vary the lifetime controller gains based on a State of Health (SoH) measure by considering the desired lifetime at every time-step. For demonstration, a 1.5 MW National Renewable Energy Laboratory (NREL) reference wind turbine is used. The proposed adaptive lifetime controller regulates structural loading in the rotor blades to guaranty a predefined damage level at the desired lifetime without sacrificing on the speed regulation performance of the wind turbine. Additionally, significant reduction in the tower fatigue damage is observed.

scholarly journals Modeling and simulation of forces applied to the horizontal axis wind turbine rotors by the vortex method coupled with the method of the blade element

2021 ◽  
Vol 12 (1) ◽  
pp. 413
Author(s):  
Ibtissem Barkat ◽  
Abdelouahab Benretem ◽  
Fawaz Massouh ◽  
Issam Meghlaoui ◽  
Ahlem Chebel
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farms ◽  
Vortex Method ◽  
Operating Conditions ◽  
Horizontal Axis ◽  
Rotor Blades ◽  
Good Representation ◽  
Horizontal Axis Wind Turbine ◽  
Blade Element

This article aims to study the forces applied to the rotors of horizontal axis wind turbines. The aerodynamics of a turbine are controlled by the flow around the rotor, or estimate of air charges on the rotor blades under various operating conditions and their relation to the structural dynamics of the rotor are critical for design. One of the major challenges in wind turbine aerodynamics is to predict the forces on the blade as various methods, including blade element moment theory (BEM), the approach that is naturally adapted to the simulation of the aerodynamics of wind turbines and the dynamic and models (CFD) that describes with fidelity the flow around the rotor. In our article we proposed a modeling method and a simulation of the forces applied to the horizontal axis wind rotors turbines using the application of the blade elements method to model the rotor and the vortex method of free wake modeling in order to develop a rotor model, which can be used to study wind farms. This model is intended to speed up the calculation, guaranteeing a good representation of the aerodynamic loads exerted by the wind.

Experimental Comparison of Three Floating Wind Turbine Concepts

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Andrew J. Goupee ◽  
Bonjun J. Koo ◽  
Richard W. Kimball ◽  
Kostas F. Lambrakos ◽  
Habib J. Dagher
Keyword(s):  
Renewable Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Operating Conditions ◽  
Scale Model ◽  
Experimental Comparison ◽  
System Response ◽  
Advantages And Disadvantages ◽  
Floating Wind Turbine ◽  
Wind Resource

Beyond many of Earth's coasts exists a vast deepwater wind resource that can be tapped to provide substantial amounts of clean, renewable energy. However, much of this resource resides in waters deeper than 60 m where current fixed bottom wind turbine technology is no longer economically viable. As a result, many are looking to floating wind turbines as a means of harnessing this deepwater offshore wind resource. The preferred floating platform technology for this application, however, is currently up for debate. To begin the process of assessing the unique behavior of various platform concepts for floating wind turbines, 1/50th scale model tests in a wind/wave basin were performed at the Maritime Research Institute Netherlands (MARIN) of three floating wind turbine concepts. The Froude scaled tests simulated the response of the 126 m rotor diameter National Renewable Energy Lab (NREL) 5 MW, horizontal axis Reference Wind Turbine attached via a flexible tower in turn to three distinct platforms, these being a tension leg-platform, a spar-buoy, and a semisubmersible. A large number of tests were performed ranging from simple free-decay tests to complex operating conditions with irregular sea states and dynamic winds. The high-quality wind environments, unique to these tests, were realized in the offshore basin via a novel wind machine, which exhibited low swirl and turbulence intensity in the flow field. Recorded data from the floating wind turbine models include rotor torque and position, tower top and base forces and moments, mooring line tensions, six-axis platform motions, and accelerations at key locations on the nacelle, tower, and platform. A comprehensive overview of the test program, including basic system identification results, is covered in previously published works. In this paper, the results of a comprehensive data analysis are presented, which illuminate the unique coupled system behavior of the three floating wind turbines subjected to combined wind and wave environments. The relative performance of each of the three systems is discussed with an emphasis placed on global motions, flexible tower dynamics, and mooring system response. The results demonstrate the unique advantages and disadvantages of each floating wind turbine platform.

Flutter stability analysis of a perforated damping blade for large wind turbines

2017 ◽  
Vol 21 (3) ◽  
pp. 973-989
Author(s):  
Da-Gang Sun ◽  
Jin-Jun Guo ◽  
Yong Song ◽  
Bi-juan Yan ◽  
Zhan-Long Li ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Turbine Blades ◽  
Time Integration ◽  
Response Analysis ◽  
Damping Factor ◽  
Deformation Model ◽  
Structural Stiffness ◽  
Structural Damping ◽  
Comparison Results

The flutter stability of wind turbine blades is one of the important contents in the research of wind turbines. The bending stiffness of blades has decreased with the development of large-sized wind turbines. To achieve damping flutter-suppressing on the long spanwise blades, perforated damping blade was proposed under the consideration of the structural damping factor and the structural stiffness in this paper. Through the study of the unit cell, the deformation model was established and the structural loss factor of the perforated damping blade was derived. The undamped blade and the perforated damping blade, combined with the relevant parameters of a 1500 kW wind turbine blade, were established to simulate the flutter-suppressing abilities and the structural stability. The dynamic response analysis was accomplished with the large deformation theory, and the MPC algorithm was used to realize grid mobile and data delivery, according to the Newmark time integration method. The comparison results show that the perforated damping blade has both a higher structural damping factor and a better structural stiffness.

Numerical Modeling of the Effects of Leading-Edge Erosion and Trailing-Edge Damage on Wind Turbine Loads and Performance

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Francesco Papi ◽  
Lorenzo Cappugi ◽  
Sebastian Perez-Becker ◽  
Alessandro Bianchini
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Prolonged Exposure ◽  
Leading Edge ◽  
Future Generation ◽  
Operating Conditions ◽  
Wind Speeds ◽  
And Performance ◽  
Lift And Drag ◽  
The Impact

Abstract Wind turbines operate in challenging environmental conditions. In hot and dusty climates, blades are constantly exposed to abrasive particles that, according to many field reports, cause significant damages to the leading edge. On the other hand, in cold climates similar effects can be caused by prolonged exposure to hail and rain. Quantifying the effects of airfoil deterioration on modern multi-MW wind turbines is crucial to correctly schedule maintenance and to forecast the potential impact on productivity. Analyzing the impact of damage on fatigue and extreme loading is also important to improve the reliability and longevity of wind turbines. In this work, a blade erosion model is developed and calibrated using computational fluid dynamics (CFD). The Danmarks Tekniske Universitet (DTU) 10 MW Reference Wind Turbine is selected as the case study, as it is representative of the future generation wind turbines. Lift and Drag polars are generated using the developed model and a CFD numerical setup. Power and torque coefficients are compared in idealized conditions at two wind speeds, i.e., the rated speed and one below it. Full aero-servo-elastic simulations of the turbine are conducted with the eroded polars using NREL's BEM-based code OpenFAST. Sixty-six 10-min simulations are performed for each stage of airfoil damage, reproducing operating conditions specified by the IEC 61400-1 power production DLC-group, including wind shear, yaw misalignment, and turbulence. Aeroelastic simulations are analyzed, showing maximum decreases in CP of about 12% as well as reductions in fatigue and extreme loading.

scholarly journals Prediction of Remaining Useful Life of Wind Turbine Bearings under Non-Stationary Operating Conditions

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3318 ◽  
Author(s):  
Lixiao Cao ◽  
Zheng Qian ◽  
Hamid Zareipour ◽  
David Wood ◽  
Ehsan Mollasalehi ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wavelet Packet ◽  
Health Indicators ◽  
Degradation Process ◽  
Remaining Useful Life ◽  
Operating Conditions ◽  
Support Vector ◽  
Useful Life ◽  
Artificial Neural Network Ann

Wind-powered electricity generation has grown significantly over the past decade. While there are many components that might impact their useful life, the gearbox and generator bearings are among the most fragile components in wind turbines. Therefore, the prediction of remaining useful life (RUL) of faulty or damaged wind turbine bearings will provide useful support for reliability evaluation and advanced maintenance of wind turbines. This paper proposes a data-driven method combining the interval whitenization method with a Gaussian process (GP) algorithm in order to predict the RUL of wind turbine generator bearings. Firstly, a wavelet packet transform is used to eliminate noise in the vibration signals and extract the characteristic fault signals. A comprehensive analysis of the real degradation process is used to determine the indicators of degradation. The interval whitenization method is proposed to reduce the interference of non-stationary operating conditions to improve the quality of health indicators. Finally, the GP method is utilized to construct the model which reflects the relationship between the RUL and health indicators. The method is assessed using actual vibration datasets from two wind turbines. The prediction results demonstrate that the proposed method can reduce the effect of non-stationary operating conditions. In addition, compared with the support vector regression (SVR) method and artificial neural network (ANN), the prediction accuracy of the proposed method has an improvement of more than 65.8%. The prediction results verify the effectiveness and superiority of the proposed method.

Dynamic Modeling and Stability Analysis of a Dual-Rotor Wind Turbine

2018 ◽  
Author(s):  
Oliver T. Filsoof ◽  
Morten H. Hansen ◽  
Anders Yde ◽  
Xuping Zhang
Keyword(s):  
Wind Turbine ◽  
Dynamic Modeling ◽  
Wind Turbines ◽  
Floquet Theory ◽  
Equations Of Motion ◽  
Response Analysis ◽  
Modal Response ◽  
Asymmetric Rotor ◽  
Modal Property ◽  
Fidelity Model

Various modal analysis methods are available for single-rotor wind turbines, but there is no report and guidance on the modal property analysis of multi-rotor wind turbines. This paper presents a dynamic modeling method for the modal response analysis of a wind turbine with two three-bladed isotropic rotors. The equations of motion are derived using Lagrange’s equations and are further linearized at a steady-state equilibrium. To avoid using Floquet Theory to remove the periodic coefficients, multi-blade coordinates are utilized. Comparison between the numerical simulations and a high-fidelity model in HAWC2 shows agreements in terms of modal frequencies. The results shows that the whirling modes splits into symmetric and asymmetric rotor modes.

Influence of Wind Turbine Aero-Elastic Load on Dynamic Response of Floating Platform

2012 ◽  
Vol 608-609 ◽  
pp. 649-652
Author(s):  
Fa Suo Yan ◽  
Hong Wei Wang ◽  
Jun Zhang ◽  
Da Gang Zhang
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Numerical Code ◽  
Floating Body ◽  
Response Analysis ◽  
Floating Platform ◽  
Floating Base ◽  
Wind Turbine System ◽  
The Difference

A numerical code, known as COUPLE, which has been developed to perform hydrodynamic analysis of floating body with a mooring system, is extended to collaborate with FAST to evaluate the interactions between wind turbine and its floating base. FAST is developed by National Renewable Energy Lab (NREL) for aeroelastic simulation of wind turbines. A dynamic response analysis of a spar type floating wind turbine system is carried out by the method. Two types of simulation of wind load are used in the analysis. One type is a constant steady force and the other is a six-component dynamic load from a turbulent wind model. Numerical results of related platform motions under random sea conditions are presented in time and frequency domain. Comparison of results is performed to explain the difference of two analyses. The conclusions derived in this study may provide reference for the design of offshore floating wind turbines.

scholarly journals Aerodynamic Performance Analysis of a Building-Integrated Savonius Turbine

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2636
Author(s):  
Zhaoyong Mao ◽  
Guangyong Yang ◽  
Tianqi Zhang ◽  
Wenlong Tian
Keyword(s):  
Performance Analysis ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
New Technology ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
High Rise ◽  
Turbine Performance ◽  
Cfd Method

The building-integrated wind turbine is a new technology for the utilization of wind energy in cities. Previous studies mainly focused on the wind turbines mounted on the roofs of buildings. This paper discusses the performance of Savonius wind turbines which are mounted on the edges of a high-rise building. A transient CFD method is used to investigate the performance of the turbine and the interaction flows between the turbine and the building. The influence of three main parameters, including the turbine gap, wind angle, and adjacent turbines, are considered. The variations of the turbine torque and power under different operating conditions are evaluated and explained in depth. It is found that the edge-mounted Savonius turbine has a higher coefficient of power than that operating in uniform flows; the average Cp of the turbine under 360-degree wind angles is 92.5% higher than the turbine operating in uniform flows. It is also found that the flow around the building has a great impact on turbine performance, especially when the turbine is located downwind of the building.

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