Loading and Design Parameter Uncertainty in the Dynamics and Performance of High-Speed-Parallel-Helical Stage of a Wind Turbine Gearbox

2013 ◽  
Author(s):  
Fisseha M. Alemayehu ◽  
Stephen Ekwaro-Osire
Keyword(s):  
Wind Turbine ◽  
Parameter Uncertainty ◽  
System Reliability ◽  
Design Parameter ◽  
High Speed ◽  
Probability Of Failure ◽  
Wind Turbine Gearbox ◽  
Input Shaft ◽  
Input Variables ◽  
And Performance

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.

Loading and Design Parameter Uncertainty in the Dynamics and Performance of High-Speed-Parallel-Helical-Stage of a Wind Turbine Gearbox1

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Fisseha M. Alemayehu ◽  
Stephen Ekwaro-Osire
Keyword(s):  
Wind Turbine ◽  
Design Parameter ◽  
High Speed ◽  
Design Parameters ◽  
Parameter Uncertainties ◽  
Component Reliability ◽  
Input Shaft ◽  
Multibody Dynamic ◽  
Input Variables ◽  
And Performance

In operation, wind turbine gearboxes (WTGs) are subjected to variable torsional and nontorsional loads. In addition, the manufacturing and assembly process of these devices results in uncertainty in the design parameters of the system. WTGs are reported to fail in their early life of operation within 3–7 years as opposed to the expected 20 years of operation. Their downtime and maintenance process is the most costly of the failures of any subassembly of wind turbines (WTs). The objective of this work is to perform a probabilistic multibody dynamic analysis (PMBDA) of the high-speed-parallel-helical-stage (HSPHS) of a WTG that considers the uncertainties of generator-side torque-loading and input-shaft speed as well as assembly and design parameter uncertainties. Component reliability (Rc) or probability of failure (Pf) and probabilistic sensitivities of all the input variables toward five performance functions have been measured and conclusions have been drawn. As opposed to the traditional deterministic approach, PMBDA has demonstrated a new aspect of design and installation of WTGs. In addition to revealing Rc or system reliability or underperformance through Pf, the method will also help designers to critically consider certain variables through the probabilistic sensitivity results.

scholarly journals Development of a wind turbine gearbox virtual load sensor using multibody simulation and artificial neural networks

2021 ◽  
Author(s):  
Baher Azzam ◽  
Ralf Schelenz ◽  
Björn Roscher ◽  
Abdul Baseer ◽  
Georg Jacobs
Keyword(s):  
Time Series ◽  
Wind Turbine ◽  
High Speed ◽  
Time Series Data ◽  
Development Trend ◽  
Series Data ◽  
Ann Model ◽  
Wind Turbine Gearbox ◽  
Virtual Sensor ◽  
Artificial Neural

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.

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
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Wind Turbine Gearbox

Electrostatic monitoring of wind turbine gearbox on oil-lubricated system

2016 ◽  
Vol 231 (19) ◽  
pp. 3649-3664 ◽  
Author(s):  
Ruochen Liu ◽  
Hongfu Zuo ◽  
Jianzhong Sun ◽  
Ling Wang
Keyword(s):  
Wind Turbine ◽  
Time Domain ◽  
Accelerated Life Test ◽  
Permutation Entropy ◽  
Life Test ◽  
Wind Turbine Gearbox ◽  
Accelerated Life ◽  
And Performance ◽  
Viable Method ◽  
Wear Condition

The electrostatic sensing technique has been verified to be a viable method for tribo-contact monitoring under laboratory conditions in previous investigations. This paper reports on the evolution of electrostatic monitoring on a real oil-lubricated wind turbine gearbox, using a modified oil-line sensor. In a nominal test and a ramp-up test, features were extracted and the presence of debris can be detected. The permutation entropy was further introduced in an accelerated life test. It can accurately reflect the wear condition of the gearboxes and detect early faults earlier than conventional techniques, which also has a better sensitivity and performance degradation trend than time-domain features.

Probabilistic Performance of Helical Compound Planetary System in Wind Turbine

2015 ◽  
Vol 10 (4) ◽  
Author(s):  
Fisseha M. Alemayehu ◽  
Stephen Ekwaro-Osire
Keyword(s):  
Wind Turbine ◽  
Multibody Systems ◽  
Planetary System ◽  
Design Parameters ◽  
Wind Turbine Gearbox ◽  
New Approach ◽  
Highly Nonlinear ◽  
Multibody Dynamic ◽  
Input Variables ◽  
Maintenance Process

The dynamics of contact, stress and failure analysis of multibody systems is highly nonlinear. Nowadays, several commercial and other analysis software dedicated for this purpose are available. However, these codes do not consider the uncertainty involved in loading, design, and assembly parameters. One of these systems with a combined high nonlinearity and uncertainty of parameters is the gearbox of wind turbines (WTs). Wind turbine gearboxes (WTG) are subjected to variable torsional and nontorsional loads. In addition, the manufacturing and assembly process of these devices results in uncertainty of the design parameters of 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 WTs. The objective of this work is to perform a probabilistic multibody dynamic analysis (PMBDA) of a helical compound planetary stage of a selected wind turbine gearbox that considers ten random variables: two loading (the rotor speed, generator side torque), and eight design parameters. The reliability or probabilities of failure of each gear and probabilistic sensitivities of the input variables toward two performance functions have been measured and conclusions have been drawn. The results revealed that PMBDA has demonstrated a new approach of gear system design beyond a traditional deterministic approach. The method demonstrated the components' reliability or probability of failure and sensitivity results that will be used as a tool for designers to make sound decisions.

Application of Wavelet De-Noising in Fault Diagnosis of Wind Turbine Gearboxes

2012 ◽  
Vol 562-564 ◽  
pp. 1091-1094 ◽  
Author(s):  
Hai Jiang Kou ◽  
Hui Qun Yuan ◽  
Xiao Yu Zhao
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Fault Location ◽  
Time Domain Analysis ◽  
Fault Detection And Diagnosis ◽  
Wind Turbine Gearbox ◽  
Stationary Noise ◽  
Wind Turbine System ◽  
Detection And Diagnosis ◽  
The Time Domain

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.

Geartrain Reduction for Real-Time Simulation of a Multibody Wind Turbine Gearbox Model

2014 ◽  
Author(s):  
Ryan Schkoda
Keyword(s):  
Wind Turbine ◽  
Real Time ◽  
High Frequency ◽  
Load Path ◽  
Wind Turbine Gearbox ◽  
Real Time Simulation ◽  
Multibody Model ◽  
Input Shaft ◽  
Time Simulation ◽  
Testing Facility

This paper presents a reduction strategy for a multibody model of a 7.5 MW gearbox located at Clemson University’s Wind Turbine Drivetrain Testing Facility in North Charleston, SC. A model reduction is needed because of a high frequency dynamic associated with the input shaft of the gearbox which prevents the model from being executed in real-time. This particular gearbox has an atypical input stage configuration whereby the load path is split into two parallel shafts before being recombined at the sun shaft. The strategy includes removing model elements associated with high frequency vibration, merging model elements, and locating model elements where needed. The presented strategy successfully removes the problematic eigenvalues, maintains basic dynamic character, and results in a multibody gearbox model suitable for real-time simulation.

scholarly journals Investigation of Dynamic Loads in Wind Turbine Drive Trains Due to Grid and Power Converter Faults

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8542
Author(s):  
Julian Röder ◽  
Georg Jacobs ◽  
Tobias Duda ◽  
Dennis Bosse ◽  
Fabian Herzog
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Power Converter ◽  
Wind Turbine Gearbox ◽  
Wind Turbine Gearbox Bearings ◽  
Grid Connection ◽  
Drive Trains ◽  
Electrical Faults ◽  
Doubly Fed ◽  
Component Loading

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.

Efficient Transient Analysis of the High-Speed Stage of a Wind Turbine Gearbox by Advanced Model Reduction Techniques and Memory-Effective Discretization

2015 ◽  
Author(s):  
Tommaso Tamarozzi ◽  
Bart Blockmans ◽  
Wim Desmet
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
High Speed ◽  
Dynamic Effects ◽  
Wind Turbine Gearbox ◽  
Premature Failure ◽  
Efficient Simulation ◽  
Model Complex ◽  
Non Linear ◽  
Flexible Multibody

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.

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