scholarly journals Investigation of Roller Sliding in Wind Turbine Gearbox High-Speed-Shaft Bearings

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


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 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.


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.


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.


2021 ◽  
pp. 0309524X2110463
Author(s):  
Jin Xu ◽  
Xian Ding ◽  
Jiuhua Wang ◽  
Junjie Zheng

Bearings are the critical parts that support the rotating of rotor of wind turbine generators. Due to high speed revolution and affected by potential misalignment between rotor and the high speed shaft in wind turbine gearbox, the fault ratio in wind turbine generator bearings is high. Once the bearings fail, it will cause gap eccentricity, even rub, or sweeping chamber between rotor and stator. Under fault conditions, the vibration signals from rotating machinery exhibits distinct second cyclostationarity. In the light of this, the fast spectral correlation based method is applied to the fault extraction of bearings in wind turbine generators. Through converting conventional correlation into summation algorithm, the computational cost is reduced largely, meanwhile, the diagnosis accuracy is guaranteed. The effectiveness of the method in this paper is verified by two fault cases from on-site wind turbines.


Tribologia ◽  
2017 ◽  
pp. 21-26 ◽  
Author(s):  
Bartosz BASTIAN ◽  
Rafał GAWARKIEWICZ ◽  
Michał WASILCZUK

A system of two taper roller bearings can carry loads with a high ratio of axial load to radial load. Such a system was proposed for a wind turbine gearbox following the poor durability of original bearing design with the aim of increasing durability. Because of size limits, a proposed system is composed of two different taper roller bearings. Standard manufacturers’ catalogues do not provide information on recommended preload or clearance conditions or the durability as a function of pre-load. That was the reason why durability was calculated on the basis of software provided by one of the manufacturers. The analysis presented in the paper shows the relationship between bearing fits, preload values, and the theoretical durability of the bearing.


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