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Book Characterization of the High Speed Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events

Download or read book Characterization of the High Speed Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer period of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.

Book Investigating Main and High Speed Shaft Bearing Reliability through Uptower Testing

Download or read book Investigating Main and High Speed Shaft Bearing Reliability through Uptower Testing written by and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most prevalent failure modes in wind turbine drivetrains are main bearing failures stemming from micropitting, white etching or axial cracks in gearbox bearings, and generator bearing failures. These failures are neither well understood nor accounted for in design standards; consequently, the mitigation strategies being developed and fielded may only partially address the physics of failure and can take years to assess. The U.S. Department of Energy continues to support research programs to investigate the influence of rolling element sliding on the formation of bearing axial cracks and main bearing micropitting.

Book Rolling Bearing Tribology

Download or read book Rolling Bearing Tribology written by Gary L. Doll and published by Elsevier. This book was released on 2022-08-20 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rolling Bearing Tribology: Tribology and Failure Modes of Rolling Element Bearings discusses these machine elements that are used to accommodate motion on or about shafts in mechanical systems, with ball bearings, cylindrical roller bearings, spherical roller bearings, and tapered roller bearings reviewed. Each bearing type experiences different kinds of motion and forces with their respective raceway, retainers and guiding flanges. The material in this book identifies the tribology of the major bearing types and how that tribology depends upon materials, surfaces and lubrication. In addition, the book describes the best practices to mitigate common failure modes of rolling element bearings. Discusses important tribological implications surrounding the performance and durability of rolling element bearings Describes how the different types of roller bearings work Explores the reasons behind the failure of roller bearings and presents information on how to mitigate those failures

Book MARE WINT

Download or read book MARE WINT written by Wiesław Ostachowicz and published by Springer. This book was released on 2016-08-30 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a holistic, interdisciplinary overview of offshore wind energy, and is a must-read for advanced researchers. Topics, from the design and analysis of future turbines, to the decommissioning of wind farms, are covered. The scope of the work ranges from analytical, numerical and experimental advancements in structural and fluid mechanics, to novel developments in risk, safety & reliability engineering for offshore wind.The core objective of the current work is to make offshore wind energy more competitive, by improving the reliability, and operations and maintenance (O&M) strategies of wind turbines. The research was carried out under the auspices of the EU-funded project, MARE-WINT. The project provided a unique opportunity for a group of researchers to work closely together, undergo multidisciplinary doctoral training, and conduct research in the area of offshore wind energy generation. Contributions from expert, external authors are also included, and the complete work seeks to bridge the gap between research and a rapidly-evolving industry.

Book Investigation of Bearing Axial Cracking Benchtop and Full Scale Test Results

Download or read book Investigation of Bearing Axial Cracking Benchtop and Full Scale Test Results written by and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most common failure mode in wind turbine gearboxes is axial cracking in intermediate and high-speed-stage bearings, also commonly called white-etching cracks (WECs). Although these types of cracks have been reported for over a decade, the conditions leading to WECs, the process by which this failure culminates, and the reasons for their apparent prevalence in wind turbine gearboxes are all highly debated. This paper summarizes the state of a multipronged research effort to examine the causes of WECs in wind turbine gearbox bearings. Recent efforts have recreated WECs on a benchtop test rig in highly loaded sliding conditions, wherein it was found that the formation of a dark etching microstructure precedes the formation of a crack, and a crack precedes the formation of white-etching microstructure. A cumulative frictional sliding energy criterion has been postulated to predict the presence of WECs. Bearing loads have also been measured and predicted in steady state and transient drivetrain operations in dynamometer testing. In addition, both loads and sliding at full scale will be measured in planned uptower drivetrain testing. If the cumulative frictional sliding energy is the dominant mechanism that causes WECs, understanding the amount of frictional sliding energy that wind turbine bearings are subjected to in typical operations is the next step in the investigation. If highly loaded sliding conditions are found uptower, similar to the examined benchtop levels, appropriate mitigation solutions can be examined, ranging from new bearing coatings and improved lubricants to changes in gearbox designs and turbine operations.

Book Transmission Distribution and Renewable Energy Generation Power Equipment

Download or read book Transmission Distribution and Renewable Energy Generation Power Equipment written by Bella H. Chudnovsky and published by CRC Press. This book was released on 2017-03-07 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: The revised edition presents, extends, and updates a thorough analysis of the factors that cause and accelerate the aging of conductive and insulating materials of which transmission and distribution electrical apparatus is made. New sections in the second edition summarize the issues of the aging, reliability, and safety of electrical apparatus, as well as supporting equipment in the field of generating renewable energy (solar, wind, tide, and wave power). When exposed to atmospheric corrosive gases and fluids, contaminants, high and low temperatures, vibrations, and other internal and external impacts, these systems deteriorate; eventually the ability of the apparatus to function properly is destroyed. In the modern world of "green energy", the equipment providing clean, electrical energy needs to be properly maintained in order to prevent premature failure. The book’s purpose is to help find the proper ways to slow down the aging of electrical apparatus, improve its performance, and extend the life of power generation, transmission, and distribution equipment.

Book Power Transmission Design

Download or read book Power Transmission Design written by and published by . This book was released on 1997 with total page 1646 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Dynamics and Vibration Analyses of Gearbox in Wind Turbine

Download or read book Dynamics and Vibration Analyses of Gearbox in Wind Turbine written by Qingkai Han and published by Springer. This book was released on 2016-09-27 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the dynamics and vibration properties of gearboxes, with a focus on geared rotor systems. It discusses mechanical theories, finite-element based simulations, experimental measurements and vibration signal processing techniques. It introduces the vibration-resonance calculation method for the geared rotor system in wind turbines and load sharing of the planetary gear train, and offers a method for calculating the vibrations of geared rotor systems under either internal excitations from gear sets or external loads transferred from wind loads. It also defines and elaborates on parameter optimization for planetary gear systems based on the torsional dynamics of wind-turbine geared rotor systems. Moreover, it describes experimental measurements of vibrations on the wind-turbine gearbox performed on the test rig and on site, and analyzes the vibration signals of different testing points, showing them in both time and frequency domains. Lastly, it lists the gear coupling frequencies and fault characteristic frequencies from the vibrations of the gearbox housing. The technologies and results presented are valuable resources for use in dynamic design, vibration prediction and analysis of gearboxes and geared rotor systems in wind turbines as well as many other machines.

Book Failure Atlas for Rolling Bearings in Wind Turbines

Download or read book Failure Atlas for Rolling Bearings in Wind Turbines written by and published by . This book was released on 2006 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Atlas is structured as a supplement to the book: T.E. Tallian: Failure Atlas for Hertz Contact Machine Elements, 2nd edition, ASME Press New York, (1999). The content of the atlas comprises plate pages from the book that contain bearing failure images, application data, and descriptions of failure mode, image, and suspected failure causes. Rolling bearings are a critical component of the mainshaft system, gearbox and generator in the rapidly developing technology of power generating wind turbines. The demands for long service life are stringent; the design load, speed and temperature regimes are demanding and the environmental conditions including weather, contamination, impediments to monitoring and maintenance are often unfavorable. As a result, experience has shown that the rolling bearings are prone to a variety of failure modes that may prevent achievement of design lives. Morphological failure diagnosis is extensively used in the failure analysis and improvement of bearing operation. Accumulated experience shows that the failure appearance and mode of failure causation in wind turbine bearings has many distinguishing features. The present Atlas is a first effort to collect an interpreted database of specifically wind turbine related rolling bearing failures and make it widely available. This Atlas is structured as a supplement to the book: T.E. Tallian: Failure Atlas for Hertz Contact Machine Elements, 2d edition, ASME Press New York, (1999). The main body of that book is a comprehensive collection of self-contained pages called Plates, containing failure images, bearing and application data, and three descriptions: failure mode, image and suspected failure causes. The Plates are sorted by main failure mode into chapters. Each chapter is preceded by a general technical discussion of the failure mode, its appearance and causes. The Plates part is supplemented by an introductory part, describing the appearance classification and failure classification systems used, and by several indexes. The present Atlas is intended as a supplement to the book. It has the same structure but contains only Plate pages, arranged in chapters, each with a chapter heading page giving a short definition of the failure mode illustrated. Each Plate page is self contained, with images, bearing and application data, and descriptions of the failure mode, the images and the suspected causes. Images are provided in two resolutions: The text page includes 6 by 9 cm images. In addition, high resolution image files are attached, to be retrieved by clicking on their 'push pin' icon. While the material in the present Atlas is self-contained, it is nonetheless a supplement to the book and the complete interpretation of the terse image descriptions and of the system underlying the failure code presupposes familiarity with the book. Since this Atlas is a supplement to the book, its chapter numbering follows that of the book. Not all failure modes covered in the book have been found among the observed wind turbines. For that reason, and because of the omission of introductory matter, the chapter numbers in this Atlas are not a continuous sequence.

Book Power Conversion and Control of Wind Energy Systems

Download or read book Power Conversion and Control of Wind Energy Systems written by Bin Wu and published by John Wiley & Sons. This book was released on 2011-08-09 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents the latest power conversion and control technology in modern wind energy systems. It has nine chapters, covering technology overview and market survey, electric generators and modeling, power converters and modulation techniques, wind turbine characteristics and configurations, and control schemes for fixed- and variable-speed wind energy systems. The book also provides in-depth steady-state and dynamic analysis of squirrel cage induction generator, doubly fed induction generator, and synchronous generator based wind energy systems. To illustrate the key concepts and help the reader tackle real-world issues, the book contains more than 30 case studies and 100 solved problems in addition to simulations and experiments. The book serves as a comprehensive reference for academic researchers and practicing engineers. It can also be used as a textbook for graduate students and final year undergraduate students.

Book Wear Analysis of Wind Turbine Gearbox Bearings

Download or read book Wear Analysis of Wind Turbine Gearbox Bearings written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this effort was to investigate and characterize the nature of surface damage and wear to wind turbine gearbox bearings returned from service in the field. Bearings were supplied for examination by S. Butterfield and J. Johnson of the National Wind Technology Center (NREL), Boulder, Colorado. Studies consisted of visual examination, optical and electron microscopy, dimensional measurements of wear-induced macro-scale and micro-scale features, measurements of macro- and micro-scale hardness, 3D imaging of surface damage, studies of elemental distributions on fracture surfaces, and examinations of polished cross-sections of surfaces under various etched and non-etched conditions.