Model based diagnostic tool for detection of gear tooth crack in a wind turbine gearbox under constant load

Author(s):  
Rishi Kumar ◽  
Sankar Kumar Roy
Author(s):  
J. R. Cho ◽  
K. Y. Jeong ◽  
M. H. Park ◽  
N. G. Park

This paper presents a dynamic finite element analysis model for a wind turbine gearbox in which a number of internal gears mesh with each other in a complex pattern. Differing from the conventional dynamic models in which the detailed gear teeth are fully modeled or gears and shafts are replaced with lumped masses, the tooth contact between a pair of gears is modeled using a spring element. The equivalent spring constant is determined by computing the stiffness of a gear tooth using a finite element analysis. The numerical accuracy of the proposed dynamic model is verified through a benchmark experiment of a gearbox with simple gear transmission system. In addition, the natural frequencies and dynamic responses of a 5 MW wind turbine gearbox that are obtained by the proposed modeling technique are given to support its validity and effectiveness.


Author(s):  
Issa S Al-Tubi ◽  
Hui Long

Wind turbine gearbox operates under a wide array of highly fluctuating and dynamic load conditions caused by the stochastic nature of wind and operational wind turbine controls. Micropitting damage is one of failure modes commonly observed in wind turbine gearboxes. This article investigates gear micropitting of high-speed stage gears of a wind turbine gearbox operating under nominal and varying load and speed conditions. Based on the ISO standard of gear micropitting (ISO/TR 15144-1:2010) and considering the operating load and speed conditions, a theoretical study is carried out to assess the risk of gear micropitting by determining the contact stress, sliding parameter, local contact temperature and lubricant film thickness along the line of action of gear tooth contact. The non-uniform distributions of temperature and lubricant film thickness over the tooth flank are observed due to the conditions of torque and rotational speed variations and sliding contact along the gear tooth flanks. The lubricant film thickness varies along the tooth flank and is at the lowest when the tip of the driving gear engages with the root of the driven gear. The lubricant film thickness increases with the increase of rotational speed and decreases as torque and sliding increase. It can be concluded that micropitting is most likely to initiate at the addendum of driving gear and the dedendum of driven gear. The lowest film thickness occurs when the torque is high and the rotational speed is at the lowest which may cause direct tooth surface contact. At the low-torque condition, the varying rotational speed condition may cause a considerable variation of lubricant film thickness thus interrupting the lubrication which may result in micropitting.


2015 ◽  
Vol 750 ◽  
pp. 96-103 ◽  
Author(s):  
Hui Long ◽  
I.S. Al-Tubi ◽  
M.T.M. Martinze

This paper presents an investigation of the effect of load variation on gear tooth surface micropitting, for an application in planet gears in a wind turbine gearbox. To study the effect of load variation, two methods are employed: an experimental testing of gear micropitting under variable loading and a probabilistic analysis of gear contact stress and specific lubricant film thickness variations using the ISO Technical Report ISO/TR 15144-1:2010. The load variation of wind turbine gearbox is derived from SCADA (Supervisory Control and Data Acquisition) data recorded in operation. Both experimental and analytical results show that high levels of contact stress, load variations and repeated load cycles are determinant factors for the initiation and propagation of micropitting of gear tooth surfaces.


Author(s):  
Qiu Yingning ◽  
Feng Yanhui ◽  
Yang Wenxian ◽  
Cao Mengnan ◽  
Wang Hao ◽  
...  

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3920
Author(s):  
Qiang Zhao ◽  
Kunkun Bao ◽  
Jia Wang ◽  
Yinghua Han ◽  
Jinkuan Wang

Condition monitoring can improve the reliability of wind turbines, which can effectively reduce operation and maintenance costs. The temperature prediction model of wind turbine gearbox components is of great significance for monitoring the operation status of the gearbox. However, the complex operating conditions of wind turbines pose grand challenges to predict the temperature of gearbox components. In this study, an online hybrid model based on a long short term memory (LSTM) neural network and adaptive error correction (LSTM-AEC) using simple-variable data is proposed. In the proposed model, a more suitable deep learning approach for time series, LSTM algorithm, is applied to realize the preliminary prediction of temperature, which has a stronger ability to capture the non-stationary and non-linear characteristics of gearbox components temperature series. In order to enhance the performance of the LSTM prediction model, the adaptive error correction model based on the variational mode decomposition (VMD) algorithm is developed, where the VMD algorithm can effectively solve the prediction difficulty issue caused by the non-stationary, high-frequency and chaotic characteristics of error series. To apply the hybrid model to the online prediction process, a real-time rolling data decomposition process based on VMD algorithm is proposed. With aims to validate the effectiveness of the hybrid model proposed in this paper, several traditional models are introduced for comparative analysis. The experimental results show that the hybrid model has better prediction performance than other comparative models.


2018 ◽  
Vol 35 (1) ◽  
pp. 415-421 ◽  
Author(s):  
Ruiming Fang ◽  
Rongyan Shang ◽  
Shunhui Jiang ◽  
Changqing Peng ◽  
Zhijun Ye

Sign in / Sign up

Export Citation Format

Share Document