scholarly journals Gaining Insights in Loading Events for Wind Turbine Drivetrain Prognostics

2020 ◽  
Author(s):  
Pieter-Jan Daems ◽  
Y. Guo ◽  
S. Sheng ◽  
C. Peeters ◽  
P. Guillaume ◽  
...  
Keyword(s):  
High Frequency ◽  
Failure Modes ◽  
Measurement Data ◽  
Wind Farms ◽  
Frequency Measurement ◽  
Operating Conditions ◽  
Failure Data ◽  
The World ◽  
Operations And Maintenance ◽  
History Of

Abstract Wind energy is one of the largest sources of renewable energy in the world. To further reduce the operations and maintenance (O&M) costs of wind farms, it is essential to be able to accurately pinpoint the root causes of different failure modes of interest. An example of such a failure mode that is not yet fully understood is white etching cracks (WEC). This can cause the bearing lifetime to be reduced to 5–10% of its design value. Multiple hypotheses are available in literature concerning its cause. To be able to validate or disprove these hypotheses, it is essential to have historic high-frequency measurement data (e.g., load and vibration levels) available. In time, this will allow linking to the history of the turbine operating data with failure data. This paper discusses the dynamic loading on the turbine during certain events (e.g., emergency stops, run-ups, and during normal operating conditions). By combining the number of specific events that each turbine has seen with the severity of each event, it becomes possible to assess which turbines are most likely to show signs of damage.

Operation and approximation based on the history of failure modes recorded by SCADA system of Amougdoul Moroccan wind farm using FMECA maintenance model

2021 ◽  
pp. 0309524X2199245
Author(s):  
Kawtar Lamhour ◽  
Abdeslam Tizliouine
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
Failure Modes ◽  
Wind Farms ◽  
Scada System ◽  
History Of ◽  
Criticality Analysis ◽  
Maintenance Model ◽  
Reliability And Availability ◽  
Critical Subsystems

The wind industry is trying to find tools to accurately predict and know the reliability and availability of newly installed wind turbines. Failure modes, effects and criticality analysis (FMECA) is a technique used to determine critical subsystems, causes and consequences of wind turbines. FMECA has been widely used by manufacturers of wind turbine assemblies to analyze, evaluate and prioritize potential/known failure modes. However, its actual implementation in wind farms has some limitations. This paper aims to determine the most critical subsystems, causes and consequences of the wind turbines of the Moroccan wind farm of Amougdoul during the years 2010–2019 by applying the maintenance model (FMECA), which is an analysis of failure modes, effects and criticality based on a history of failure modes occurred by the SCADA system and proposing solutions and recommendations.

Reliability Analysis of Water Mist Systems

2007 ◽  
Author(s):  
Shuzhen Xu ◽  
Enrique A. Susemihl
Keyword(s):  
Failure Modes ◽  
National Fire Protection Association ◽  
Water Mist ◽  
Confidence Bounds ◽  
Failure Data ◽  
Importance Analysis ◽  
History Of ◽  
Operational Failures ◽  
System Configurations ◽  
Failure Probabilities

This paper presents some preliminary results from a reliability study of water mist systems conducted at FM Global. The study includes a detailed Failure Modes and Effects Analysis (FMEA) to identify all the major potential failure modes, which include demand, quiescent and operational failures. Various fault trees are thus constructed for the typical water mist system configurations to evaluate the failure probabilities. However, due to the short history of industrial application of water mist systems, no specific reliability data are available. Therefore, in the calculation of system failure probability, the component failure data are obtained from other applications. The failure probabilities and the confidence bounds of the typical water mist systems listed in the Standard 750 of the National Fire Protection Association are compared in the paper. The major failure modes identified through an importance analysis are also presented.

scholarly journals Application of High-Frequency Leakage Current Model for Characterizing Failure Modes in Digital Logic Gates

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2906
Author(s):  
Zahra Abedi ◽  
Sameer Hemmady ◽  
Thomas Antonsen ◽  
Edl Schamiloglu ◽  
Payman Zarkesh-Ha
Keyword(s):  
Predictive Model ◽  
Leakage Current ◽  
Electromagnetic Interference ◽  
High Frequency ◽  
Failure Modes ◽  
Current Model ◽  
Measurement Data ◽  
Logic Gates ◽  
Cmos Inverter ◽  
The Impact

In this paper, a predictive model is developed to characterize the impact of high-frequency electromagnetic interference (EMI) on the leakage current of CMOS integrated circuits. It is shown that the frequency dependence can be easily described by a transfer function that depends only on a few dominant parasitic elements. The developed analytical model is successfully compared against measurement data from devices fabricated using 180 nm, 130 nm, and 65 nm standard CMOS processes through TSMC. Based on the predictive model, the impact of EMI on leakage current in a CMOS inverter is reduced by increasing the frequency from 10 MHz to 4 GHz.

scholarly journals Failure Modes, Effects and Criticality Analysis for Wind Turbines Considering Climatic Regions and Comparing Geared and Direct Drive Wind Turbines

2018 ◽  
Author(s):  
Samet Ozturk ◽  
Vasilis Fthenakis ◽  
Stefan Faulstich
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Failure Modes ◽  
Wind Farms ◽  
Weather Conditions ◽  
Direct Drive ◽  
Climatic Regions ◽  
Failure Data ◽  
Criticality Analysis ◽  
Reliability And Availability

The wind industry is looking for ways to accurately predict the reliability and availability of newly installed wind turbines. Failure modes, effects and criticality analysis (FMECA) is a technique utilized for determining the critical subsystems of wind turbines. There are several studies which applied FMECA for wind turbines in the literature, but no studies so far have considered different weather conditions or climatic regions. Furthermore, various design types of wind turbines have been analyzed applying FMECA but no study so far has applied FMECA to compare the reliability of geared and direct-drive wind turbines. We propose to fill these gaps by using Koppen-Geiger climatic regions and two different turbine models of direct-drive and geared-drive concepts. A case study is applied on German wind farms utilizing the WMEP database which contains wind turbine failure data from 1989 to 2008. This proposed methodology increases the accuracy of reliability and availability predictions and compares different wind turbine design types and eliminates underestimation of impacts of different weather conditions.

scholarly journals Nikola Tesla and medicine: 160th anniversary of the birth of the genius who gave light to the world - part I

2016 ◽  
Vol 69 (9-10) ◽  
pp. 313-322
Author(s):  
Danijela Vucevic ◽  
Drago Djordjevic ◽  
Tatjana Radosavljevic
Keyword(s):  
High Frequency ◽  
X Rays ◽  
X Ray ◽  
Nikola Tesla ◽  
Wide Range ◽  
The World ◽  
Biologic Effects ◽  
History Of ◽  
The Impact ◽  
Harmful Effects

Introduction. The interest in Nikola Tesla, a scientist, physicist, engineer and inventor, is constantly growing. In the millennia-long history of human civilization, it is almost impossible to find another person whose life and work has been under so much scrutiny of such a wide range of researchers, medical professionals included. Although Tesla was not primarily dedicated to biomedical research, his work significantly contributed to the development of radiology, and high frequency electrotherapy. This paper deals with the impact of Tesla?s work on the development of a new medical branch - radiology. Nikola Tesla and the Discovery of X-ray radiation. Tesla pioneered the use of X-rays for medical purposes, practically laying the foundations of radiology. Namely, since 1887, Tesla periodically experimented with X-rays, at that time still unknown and unnamed, which he called "shadowgraphs". Moreover, at the end of 1894, he conducted extensive research focusing on X-rays, but unfortunately it was interrupted after the fire burning down his laboratory in 1895. In 1896 and 1897, Tesla published ten papers on the biologic effects of X-ray radiation. All his studies on X-rays were experimental. During 1896 and 1897, Tesla continued improving X-ray devices. Apart from this, Tesla was the first to point out the harmful effects of exposure to X-ray radiation on human body. Conclusion. Nikola Tesla was a visionary genius of the future. Tesla?s pioneer steps, made more than a century ago in the domain of radiology, are still being used today.

High Frequency Measurement Techniques for On-Chip Inductors

2010 ◽  
Vol 2010 (1) ◽  
pp. 000886-000890
Author(s):  
Bruce C. Kim ◽  
Dae-Hyun Han ◽  
Seok-Ho Noh
Keyword(s):  
Wireless Communication ◽  
Resonance Frequency ◽  
High Frequency ◽  
Measurement Techniques ◽  
Measurement Data ◽  
Frequency Measurement ◽  
Quality Factors ◽  
Wireless Applications ◽  
Spiral Inductors ◽  
On Chip

This paper presents high frequency measurement techniques of on-chip inductors in giga Hertz range for wireless communication products. The on-chip inductors were fabricated on high resistive substrate to reduce loss. We compared several different on-chip inductors for self-resonance frequency and quality factors. The collection of measurement data could be used for the guideline of designing practical spiral inductors for wireless applications.

The Wild Side of the Street

2018 ◽  
Author(s):  
Louçã Francisco ◽  
Ash Michael
Keyword(s):  
Seventeenth Century ◽  
High Frequency ◽  
Bank Lending ◽  
High Frequency Trading ◽  
Market Manipulation ◽  
Rating Agencies ◽  
The World ◽  
European Colonization ◽  
Financial Scandals ◽  
History Of

Chapter 9 traces a history of bubbles and financial scandals from the Dutch tulip mania of the seventeenth century to frauds associated with European colonization of the Americas to financial misdeeds of the twentieth and twenty-first centuries. Dirty finance is everywhere. Sometimes it is the source of the funds: the world’s most reputable banks have handled funds from highly disreputable sources. In other cases, clean wealth goes through dirty handling. Offshore finance shelters the great family fortunes, at the edge of legality. High frequency trading blurs the line between quick wits and market manipulation. Cartels of traders enrich themselves at the expense of clients. The rating agencies rate complex securities as sound with minimal investigation. In the Libor scandal, the biggest banks conspired to mislead the world about inter-bank lending. A description of the instruments, transactions, and the mechanisms of manipulation and fraud is provided.

A History of the World Semiconductor Industry

IEE Review ◽  
1991 ◽  
Vol 37 (10) ◽  
pp. 355
Author(s):  
D.A. Gorham
Keyword(s):  
Semiconductor Industry ◽  
The World ◽  
History Of

The problem of periodization of the history of religion

1997 ◽  
pp. 3-8
Author(s):  
Borys Lobovyk
Keyword(s):  
Religious Studies ◽  
Human Being ◽  
Religious Development ◽  
History Of Religion ◽  
The Social ◽  
The World ◽  
History Of ◽  
Role Of Religion

An important problem of religious studies, the history of religion as a branch of knowledge is the periodization process of the development of religious phenomenon. It is precisely here, as in focus, that the question of the essence and meaning of the religious development of the human being of the world, the origin of beliefs and cult, the reasons for the changes in them, the place and role of religion in the social and spiritual process, etc., are converging.

Mülteci olmak: Mersin’de yaşayan Filistinli mültecilerin göç hikâyeleri

2016 ◽  
Vol 3 (2) ◽  
pp. 200-224
Author(s):  
Bilge Deniz Çatak
Keyword(s):  
Oral History ◽  
Daily Life ◽  
Palestinian Refugees ◽  
Emotional Bonds ◽  
The World ◽  
History Of ◽  
Oral History Interviews ◽  
Refugee Experience

Filistin tarihinde yaşanan 1948 ve 1967 savaşları, binlerce Filistinlinin başka ülkelere göç etmesine neden olmuştur. Günümüzde, dünya genelinde yaşayan Filistinli mülteci sayısının beş milyonu aştığı tahmin edilmektedir. Ülkelerine geri dönemeyen Filistinlilerin mültecilik deneyimleri uzun bir geçmişe sahiptir ve köklerinden koparılma duygusu ile iç içe geçmiştir. Mersin’de bulunan Filistinlilerin zorunlu olarak çıktıkları göç yollarında yaşadıklarının ve mülteci olarak günlük hayatta karşılaştıkları zorlukların Filistinli kimlikleri üzerindeki etkisi sözlü tarih yöntemi ile incelenmiştir. Farklı kuşaklardan sekiz Filistinli mülteci ile yapılan görüşmelerde, dünyanın farklı bölgelerinde mülteci olarak yaşama deneyiminin, Filistinlilerin ulusal bağlılıklarına zarar vermediği görülmüştür. Filistin, mültecilerin yaşamlarında gelenekler, değerler ve duygusal bağlar ile devam etmektedir. Mültecilerin Filistin’den ayrılırken yanlarına aldıkları anahtar, tapu ve toprak gibi nesnelerin saklanıyor olması, Filistin’e olan bağlılığın devam ettiğinin işaretlerinden biridir.ABSTRACT IN ENGLISHPalestinian refugees’ lives in MersinIn the history of Palestine, 1948 and 1967 wars have caused fleeing of thousands of Palestinians to other countries. At the present time, its estimated that the number of Palestinian refugees worldwide exceeds five million. The refugee experience of Palestinians who can not return their homeland has a long history and intertwine with feeling of deracination. Oral history interviews were conducted on the effects of the displacement and struggles of daily life as a refugee on the identity of Palestinians who have been living in Mersin (city of Turkey). After interviews were conducted with eight refugees from different generations concluded that being a refugee in the various parts of the world have not destroyed the national entity of the Palestinians. Palestine has preserved in refugees’ life with its traditions, its values, and its emotional bonds. Keeping keys, deeds and soil which they took with them when they departed from Palestine, proving their belonging to Palestine.

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