Wind Turbine Main Bearing Diagnosis - A Proposal of Data Processing and Decision Making Procedure under Non Stationary Load Condition

2012 ◽  
Vol 518 ◽  
pp. 437-444 ◽  
Author(s):  
Radoslaw Zimroz ◽  
Walter Bartelmus ◽  
Tomasz Barszcz ◽  
Jacek Urbanek
Keyword(s):  
Decision Making ◽  
Wind Turbines ◽  
High Speed ◽  
Dimensional Space ◽  
Good Condition ◽  
Load Condition ◽  
Diagnostic System ◽  
Operating Conditions ◽  
Main Bearing ◽  
Diagnostic Features

Condition Monitoring of bearings used in Wind Turbines (WT) is an important issue. In general, bearings diagnostics is well-recognized field; however it is not the case for machines working under non-stationary load. An additional difficulty is that the Main Bearing (MB) discussed here, it is used to support low speed shaft, so dynamic response of MB is not clear as for a high-speed shaft. In the case of varying load/speed a vibration signal acquired from bearings is affected by operation and makes the diagnosis difficult. These difficulties come from the variation of diagnostic features caused mostly by load/speed variation, low energy of sought features and high noise levels. In the paper a novel diagnostic approach is proposed for main rotor bearings used in wind turbines. From a commercial diagnostic system two kind of information have been acquired: peak-to-peak vibration acceleration and generator power that is related to the operating conditions. The received data cover the period of several months, when the bearing has been replaced due to its failure and the new one has been installed. Due to serious variability of the mentioned data, a decision-making regarding the condition of bearings is pretty difficult. Application of classical statistical pattern recognition for data from the period A (bad condition) and the period B (after replacement, good condition) is not sufficient because the probability density functions of features overlap each other (pdf of peak-to-peak feature for bad and good conditions). Proposed approach is based on an idea proposed earlier for planetary gearboxes, i.e. to analyse data for bad/good conditions in two-dimensional space,feature - load. It is shown that the final data presentation is a good basis to the very successful classification of data (i.e. recognition of damaged and undamaged bearings).

Study on Unified Chaotic System-Based Wind Turbine Blade Fault Diagnostic System

2015 ◽  
Vol 25 (03) ◽  
pp. 1550042 ◽  
Author(s):  
Ying-Che Kuo ◽  
Chin-Tsung Hsieh ◽  
Her-Terng Yau ◽  
Yu-Chung Li
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Chaotic System ◽  
Wind Turbines ◽  
Diagnostic System ◽  
Vibration Signal ◽  
Wind Turbine Blade ◽  
Operating Conditions ◽  
Unified Chaotic System ◽  
Fault Diagnostic

At present, vibration signals are processed and analyzed mostly in the frequency domain. The spectrum clearly shows the signal structure and the specific characteristic frequency band is analyzed, but the number of calculations required is huge, resulting in delays. Therefore, this study uses the characteristics of a nonlinear system to load the complete vibration signal to the unified chaotic system, applying the dynamic error to analyze the wind turbine vibration signal, and adopting extenics theory for artificial intelligent fault diagnosis of the analysis signal. Hence, a fault diagnostor has been developed for wind turbine rotating blades. This study simulates three wind turbine blade states, namely stress rupture, screw loosening and blade loss, and validates the methods. The experimental results prove that the unified chaotic system used in this paper has a significant effect on vibration signal analysis. Thus, the operating conditions of wind turbines can be quickly known from this fault diagnostic system, and the maintenance schedule can be arranged before the faults worsen, making the management and implementation of wind turbines smoother, so as to reduce many unnecessary costs.

Experimental investigation of cage motions in an angular contact ball bearing

2017 ◽  
Vol 231 (8) ◽  
pp. 1041-1055 ◽  
Author(s):  
Baogang Wen ◽  
Hongjun Ren ◽  
Hao Zhang ◽  
Qingkai Han
Keyword(s):  
Experimental Investigation ◽  
High Speed ◽  
Ball Bearing ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Axial Loads ◽  
Angular Contact Ball Bearing ◽  
Radial Forces ◽  
External Loads

The commonly known effects of both the rotating speeds and external loads on the bearing dynamics or life behaviors are mostly caused by its cage dynamics, because of the complicated contact and collision interactions between the cage and other parts such as the inner or outer rings and balls. In this paper, experimental investigation of dynamic motions of a cage is carried out under various rotating speeds and external loads in a ball bearing. On a bearing test rig, the cage motions in axial and radial directions are measured by use of eddy transducers installed inside the bearing house and the subpanel. Then the measured results are analyzed by fast Fourier transform and compared at different operating conditions including rotating speeds, axial and radial forces, or moments. The three-dimensional space motions of the cage are also constructed to illustrate its different modes. Results reveal that the cage motions are typically periodic in the three directions. The motion frequencies consist of the cage rotating frequency and its multi-frequency, the inner ring rotating frequency, and also some combination frequencies of the cage and inner ring. The obtained characteristic frequencies of the cage motion in axial are similar to that in radial, but different in the variety of amplitudes under the same operating conditions. The increment of rotating speeds and axial loads of the bearing gradually make the whirl trajectories of the cage mass center regular, and enlarge its whirl radii. Instead, the whirl trajectories change from well-defined patterns to complicated ones, and its whirl radii decrease on increasing the radial loads and moments of the bearing. All the obtained experimental results are useful references for dynamic design and life prediction of high-speed and low-load bearings commonly used in many machines.

scholarly journals STAND FOR RESEARCH PARAMETERS OF ELEMENTS OF LUBRICATION SYSTEMS OF HIGH-SPEED INTERNAL COMBUSTION ENGINES

2021 ◽  
pp. 73-79
Author(s):  
D.V. Kurnosenko ◽  
V.P. Savchuk ◽  
E.V. Belousov ◽  
А.К. Dzygar ◽  
A.I. Kotov
Keyword(s):  
High Speed ◽  
Internal Combustion Engines ◽  
Diagnostic System ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Engine Oil ◽  
Operating Parameters ◽  
Combustion Engines ◽  
Lubrication System ◽  
Oil Pump

The issues of studying the operating parameters of the elements of lubrication systems for high-speed internal combustion engines preceded the creation of the stand. The engine lubrication system D-246.4 was chosen as a prototype. With the help of this stand it became possible to study the lubrication system for the following characteristics: change the performance of the engine oil pump D-246.4, change and control the engine oil temperature, control the pressure drop on the oil filter, control the engine oil flow, throttle oil at the inlet to the oil pump and on the conditional supply line to the friction units, measuring the vacuum of the system on the suction of the oil pump and recording the parameters of the pulsation of the oil pressure generated by the oil pump. To build mathematical models of the components in the lubrication systems of marine internal combustion engines there is a need to determine their operating parameters. In real operating conditions, such measurements cannot be obtained due to the lack of the necessary test equipment (TE) and the possibility of its installation. The authors describe in detail all the components of the stand for studying the parameters of the elements of lubrication systems of high-speed internal combustion engines, their technical characteristics, describes the diagnostic complex, which recorded the results of research, the results of measuring engine oil pressure pulsation. The stand is used to study the operating parameters of the oil pump and filter used for water. Signals are registered using the Autoscanner diagnostic system. The diagnostic complex is a 64-channel oscilloscope that is connected to a personal computer. This stand for studying the operating parameters of the elements of the lubrication system provides sufficient opportunities to simulate the operating conditions of the elements of the supply and purification of oil and register them both visually and with digital sensors and diagnostic system Autoscanner, digital oscilloscopes or other measuring instruments capable of recording and storing the received data.

Wind Speed Dependency of Low-Frequency Vibration Levels in Full-Scale Wind Turbines

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Xavier Escaler ◽  
Toufik Mebarki
Keyword(s):  
Wind Speed ◽  
Wind Turbines ◽  
High Speed ◽  
Wind Farm ◽  
Low Frequency ◽  
Average Frequency ◽  
Operating Conditions ◽  
Positive Slope ◽  
Low Frequency Vibration ◽  
Linear Fit

A series of continuous vibration measurements in 14 upwind wind turbines of the same model and belonging to the same wind farm have been conducted. The data were acquired over a period lasting approximately half a year. The tower axial vibration acceleration has been monitored in the frequency band from 0 to 10 Hz with an accelerometer mounted on the gearbox casing between the intermediate and the high-speed shafts. It has been observed that the average frequency spectrum is dominated by the blade passing frequency in all the wind turbines. The evolution of the vibration magnitudes over the entire range of operating conditions is also very similar for all the wind turbines. The root-mean-square (rms) acceleration value has been correlated with the wind speed, and it has been found that a linear fit with a positive slope is a useful model for prediction purposes.

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 Frequency Scan–Based Mitigation Approach of Subsynchronous Control Interaction in Type-3 Wind Turbines

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4626
Author(s):  
Faris Alatar ◽  
Ali Mehrizi-Sani
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
Operating Conditions ◽  
Steady State Operation ◽  
Significant Damage ◽  
Frequency Scan ◽  
Type 3 ◽  
Phase Angles ◽  
Wind Energy Resources ◽  
Control Interaction

Integration of wind energy resources into the grid creates several challenges for power system dynamics. More specifically, Type-3 wind turbines are susceptible to subsynchronous control interactions (SSCIs) when they become radially connected to a series-compensated transmission line. SSCIs can cause disruptions in power generation and can result in significant damage to wind farm (WF) components and equipment. This paper proposes an approach to mitigate SSCIs using an online frequency scan, with optimized phase angles of voltage harmonic injection to maintain steady-state operation, to modify the controllers or the operating conditions of the wind turbine. The proposed strategy is simulated in PSCAD/EMTDC software on the IEEE second benchmark model for subsynchronous resonance. Simulation results demonstrate the effectiveness of this strategy by ensuring oscillations do not grow.

scholarly journals The Influence of Carrier Air Preheating on Autoignition of Inline-Injected Hydrogen–Nitrogen Mixtures in Vitiated Air of High Temperature

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Christoph A. Schmalhofer ◽  
Peter Griebel ◽  
Manfred Aigner
Keyword(s):  
Hydrogen Content ◽  
Gas Turbines ◽  
High Speed ◽  
Flame Stabilization ◽  
Operating Conditions ◽  
Promoting Effect ◽  
Experimental Conditions ◽  
Lean Premixed Combustion ◽  
Image Velocimetry ◽  
Fuel Mixtures

The use of highly reactive hydrogen-rich fuels in lean premixed combustion systems strongly affects the operability of stationary gas turbines (GT) resulting in higher autoignition and flashback risks. The present study investigates the autoignition behavior and ignition kernel evolution of hydrogen–nitrogen fuel mixtures in an inline co-flow injector configuration at relevant reheat combustor operating conditions. High-speed luminosity and particle image velocimetry (PIV) measurements in an optically accessible reheat combustor are employed. Autoignition and flame stabilization limits strongly depend on temperatures of vitiated air and carrier preheating. Higher hydrogen content significantly promotes the formation and development of different types of autoignition kernels: More autoignition kernels evolve with higher hydrogen content showing the promoting effect of equivalence ratio on local ignition events. Autoignition kernels develop downstream a certain distance from the injector, indicating the influence of ignition delay on kernel development. The development of autoignition kernels is linked to the shear layer development derived from global experimental conditions.

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