Optimal Maintenance Interval for Wind Turbine Gearbox

2011 ◽  
Vol 130-134 ◽  
pp. 112-118 ◽  
Author(s):  
Meng Na Deng ◽  
Yun Hai Yu ◽  
Liang Chen ◽  
Hong Shan Zhao

A maintenance interval optimization model for wind turbine gearbox considering the maximization component profit per unit time was presented in this paper. First, the principle and configuration of gearbox were introduced, and the failure characteristic is analyzed as well as the failure rate distribution of components in gearbox. Then, the concept of component income coefficient λ and element utilizing rate per unit time U(t) were given. λ describes the proportion that component takes up the total income of wind turbine electric power sale,and U(t) represents the average income per unit time to wind turbine electric power sale during 0~t. Based on above two concepts the model of optimizing maintenance interval was proposed. Last, the paper used the proposed method to evaluate wind turbine gearbox maintenance interval in an actual wind farm. The simulating results indicates that the component profits per unit time for gears, intermediate speed shaft bearings and high speed shaft bearings increases by 16.88%, 30.26% and 32.59% respectively.

Author(s):  
Baher Azzam ◽  
Ralf Schelenz ◽  
Björn Roscher ◽  
Abdul Baseer ◽  
Georg Jacobs

AbstractA current development trend in wind energy is characterized by the installation of wind turbines (WT) with increasing rated power output. Higher towers and larger rotor diameters increase rated power leading to an intensification of the load situation on the drive train and the main gearbox. However, current main gearbox condition monitoring systems (CMS) do not record the 6‑degree of freedom (6-DOF) input loads to the transmission as it is too expensive. Therefore, this investigation aims to present an approach to develop and validate a low-cost virtual sensor for measuring the input loads of a WT main gearbox. A prototype of the virtual sensor system was developed in a virtual environment using a multi-body simulation (MBS) model of a WT drivetrain and artificial neural network (ANN) models. Simulated wind fields according to IEC 61400‑1 covering a variety of wind speeds were generated and applied to a MBS model of a Vestas V52 wind turbine. The turbine contains a high-speed drivetrain with 4‑points bearing suspension, a common drivetrain configuration. The simulation was used to generate time-series data of the target and input parameters for the virtual sensor algorithm, an ANN model. After the ANN was trained using the time-series data collected from the MBS, the developed virtual sensor algorithm was tested by comparing the estimated 6‑DOF transmission input loads from the ANN to the simulated 6‑DOF transmission input loads from the MBS. The results show high potential for virtual sensing 6‑DOF wind turbine transmission input loads using the presented method.


2019 ◽  
Author(s):  
David Vaes ◽  
Yi Guo ◽  
Pietro Tesini ◽  
Jonathan A Keller

Author(s):  
Fisseha M. Alemayehu ◽  
Stephen Ekwaro-Osire

The Wind Turbine Gearboxes (WTGs) are highly subjected to variable torsional and non-torsional loads. In addition, the manufacturing and assembly process of these devices results in uncertainty in the system. These gearboxes are reported to fail in their early life of operation, within three to seven years as opposed to the expected twenty years of operation. Their downtime and maintenance process is the most costly of any failure of subassembly of wind turbines. The objective of this work is to perform a probabilistic multibody dynamic analysis (PMBDA) of the high-speed-parallel-helical stage of the gearbox of wind turbine that considers uncertainty of generator side torque loading and the input shaft speed, assembly errors and design parameter uncertainty. System reliability, probability of failure, and probabilistic sensitivities of all the input variables towards several performance functions have been measured and conclusions have been drawn. PMBDA has demonstrated a new dimension of design and installation of wind turbine gearboxes than traditional deterministic approach. In addition to revealing system reliability or under-performance through probability of failure, the method will also help designers to consider certain variables critically through the sensitivity results.


2012 ◽  
Vol 608-609 ◽  
pp. 522-528
Author(s):  
Hong Shan Zhao ◽  
Yan Sheng Liu ◽  
Xiao Tian Zhang ◽  
Wei Guo

Fault of gearbox is one of the significant causes which lead to high cost of wind farm, so early fault prediction of gearbox is meaningful for ensuring reliable running and reducing maintenance costs. With condition monitoring data, the relation between gearbox temperature and potential faults was researched and a new method for online fault prediction of wind turbine gearbox was presented. First, the temperature prediction model for normal behavior of gearbox was built up by non-linear regression analysis. Then, a detecting function which can indicate the deviation between actual running state and prediction state of gearbox was introduced. The condition of gearbox could be monitored by comparing the real-time value of detecting function with the chosen threshold. Theoretical analysis and simulation results demonstrated that this method could predict the abnormality of gearbox in time, and it can be applied to monitor the running condition of gearbox.


2012 ◽  
Vol 562-564 ◽  
pp. 1091-1094 ◽  
Author(s):  
Hai Jiang Kou ◽  
Hui Qun Yuan ◽  
Xiao Yu Zhao

Fault detection and diagnosis of a wind turbine gearbox are important to ensure the reliability and useful life of the wind turbine system. In this paper, an experimental test in wind turbine gearboxes is carried out to obtain faulted information which consists of response random non-stationary noise and the additional response due to failure. An approach, using wavelet de-noising method, is proposed for removing non-stationary noise from the recorded signals. The time domain analysis and frequency analysis are used to diagnose the fault location of the machine accurately. It is shown that wavelet de-noising method provides a better correction than conventional method in order to remove non-stationary noise. Diagnosis results indicate that the high-speed shaft of wind turbine gearboxes has a serious imbalance.


Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8542
Author(s):  
Julian Röder ◽  
Georg Jacobs ◽  
Tobias Duda ◽  
Dennis Bosse ◽  
Fabian Herzog

Electrical faults can lead to transient and dynamic excitations of the electromagnetic generator torque in wind turbines. The fast changes in the generator torque lead to load oscillations and rapid changes in the speed of rotation. The combination of dynamic load reversals and changing rotational speeds can be detrimental to gearbox components. This paper shows, via simulation, that the smearing risk increases due to the electrical faults for cylindrical roller bearings on the high speed shaft of a wind turbine research nacelle. A grid fault was examined for the research nacelle with a doubly fed induction generator concept. Furthermore, a converter fault was analyzed for the full size converter concept. Both wind turbine grid connection concepts used the same mechanical drive train. Thus, the mechanical component loading was comparable. During the grid fault, the risk of smearing increased momentarily by a maximum of around 1.8 times. During the converter fault, the risk of smearing increased by around 4.9 times. Subsequently, electrical faults increased the risk of damage to the wind turbine gearbox bearings, especially on the high speed stage.


2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Randall S. Jackson ◽  
Ryoichi Amano

The advancement of wind energy as an alternative source to hydrocarbons depends heavily on research activities in turbulence modeling and experimentation. The velocity deficit behind wind turbines affects the power output and efficiency of a wind farm. Being able to simulate the wake dynamics of a wind turbine effectively can result in optimum spacing, longer wind turbine life, and shorter payback on the wind farm investment. Two-equation turbulence closure models, such as k–ε and k–ω, are used extensively to predict wind turbine performance and velocity deficit profiles. The application of the Reynolds stress model (RSM) turbulence closure method has been limited to few studies where the rotor is modeled as an actuator disk (AD). The computational cost associated with RSM has made it challenging for simulations where the rotor is discretized directly; however, with advances in computer speed and power coupled with parallel computing architecture, RSM may be a better turbulence closure option. In this research, wind tunnel experiments were conducted, using hot-wire anemometry, to measure the velocity deficit profiles at different wake locations behind a small-scale, three-bladed, horizontal-axis wind turbine (HAWT). Experiments were also performed with two and three HAWTs in series to evaluate the change in velocity deficit and turbulence intensity (TI). High-speed imaging with an oil-based mist captured the vortices produced at the blade tips and showed the vortices dissipated approximately three rotor diameters downstream. Computational fluid dynamics (CFD) simulations were performed to predict the velocity deficit at wake locations matching the experiments. The Reynolds stress model was applied to a fully discretized rotor with a tower and nacelle included in the simulation. A steady-state moving reference frame (MRF) model was created with the computational domain subdivided into rotating and stationary domains. The MRF results were used as an initial condition for time-accurate rigid body motion (RBM) simulations. The RBM CFD simulations showed excellent agreement with experimental measurements for velocity deficit after properly accounting for experimental boundary effects. Isosurfaces of the Q-criterion highlighted the vortices produced at the blade tips and were consistent with high-speed images.


Author(s):  
Tommaso Tamarozzi ◽  
Bart Blockmans ◽  
Wim Desmet

Modern wind turbines are designed to cope with their increased size and capacity. One of the most expensive components of these machines is the gearbox. Its design is more complex than a mere upscaling exercise from predecessors. The stress levels experienced by the different gear stages, the dynamic effects induced by their size and the unparalleled loads transmitted are some of the challenges that design engineers face. Moreover, unexpected events that load the wind turbines such as voltage dips, wind gusts or emergency breaking are expected to be major contributors to the premature failure of these gearboxes. The lack of engineering experience at this scale calls for accurate and efficient simulation tools thereby enabling reliable gearbox design. Standard lumped-parameters models or rigid multibody approaches do not provide a sufficient level of details to study the dynamic effects induced by e.g. gear design modifications (micro-geometry) or to analyze local stress concentrations. More advanced numerical tools are available such as flexible multibody or non-linear FE and allow to model complex contact interactions including all the relevant dynamic effects. Unfortunately the level of mesh refinement needed for an accurate analysis causes these simulations to be computationally expensive with time scales of several weeks to perform a single full rotation of a gear pair. This work introduces a novel efficient simulation tool for dynamic analysis of transmissions. This tool adopts a flexible multibody paradigm but incorporates several advanced features that allows to run simulations up to two orders of magnitudes faster as compared to non-linear FE with the same level of accuracy. A unique non-linear parametric model order reduction technique is used to develop a simulation strategy that is quasi mesh-independent allowing the usage of very fine FE meshes. Finally, in order to limit the memory consumption, a technique is developed to be able to finely mesh only a few of the gears teeth while the remaining gears are coarsely meshed. The main novelty of this approach lies in the possibility to perform full gear rotations without losing spatial resolution as compared to a finely meshed gear. After an accuracy check performed with a sample pair of helical gears, the framework is used to simulate the high speed stage of a three-stage wind turbine gearbox. The combined efficiency and accuracy of the approach is demonstrated by performing a dynamic stress analysis of the high-speed stage with and without a tip-relief modification. Accuracy of the results, simulation time, and memory usage are assessed.


2015 ◽  
Vol 793 ◽  
pp. 333-337 ◽  
Author(s):  
Abadal Salam T. Hussain ◽  
S. Faiz Ahmed ◽  
F. Malek ◽  
M.S. Jawad ◽  
Nursabrina Noorpi ◽  
...  

In many countries fossil fuels are used as the main source to generate electricity, but due to the increase in energy consumption and the rapid depletion of the fossil fuel resources, the demand of alternate energy sources such as solar, wind or hydro power becomes high [1]. In this paper wind energy as an alternate energy resource for electric power generation is proposed in the form of a small wind farm for grid-connected application in Perlis Malaysia. The monthly wind speed data of Perlis which is the smallest state of Malaysia were measured and the wind mill parameters such as Air Density, Blade Length, Power Coefficient and Blade Length were calculated. The mechanical output power of the proposed wind turbine form is calculated to check out its performance and reliability. The results showed that the proposed wind energy power generating system is a good choice and can be implemented in Malaysia to provide enough power for small towns and rural areas.


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