Renewable Energy Global Innovations features: Comparison and verification of the deviation between guaranteed and measured wind turbine power performance in complex terrain

 

Journal Reference

Energy, Volume 85, 2015, Pages 23-29.

Hyunseok Oh¹, Bumsuk Kim²

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1. Korean Register of Shipping, 6F, Haewoon-Bldg, Gukhoe-daero68-gil 17, Yeongdeungpo-gu, Seoul, 151-742, Republic of Korea
2. Faculty of Wind Energy Engineering, Jeju National University, Jejudaehak-ro 102, Jeju-si, Jeju Special Self-Governing Province, 690-756, Republic of Korea

Abstract

After a wind farm construction is completed, the power performance guaranteed by the wind turbine manufacturer is usually verified based on the international standard IEC61400-12-1. Because of an insufficient project budget and the constraint on the minimum separation distance of the meteorological mast from the installed wind turbines, it is a common practice to verify the power performance of one representative wind turbine and apply the result as the reference power performance guarantee for all the wind turbines. In this study, the power performances of five wind turbines operating at a commercial wind farm located on complex terrain were measured and analyzed. The results showed large power performance differences between the turbines. Because the power performance of one representative wind turbine cannot guarantee the power performances of all the wind turbines in a wind farm located on complex terrain, we submit that it is necessary to carry out power performance verifications on many or all of the wind turbines.

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About The Author

Bumsuk Kim received his B.S. in Mechanical Engineering from Korea Maritime and Ocean University in 2001 and M.S. and Ph.D. from the same university in 2003 and 2005. After receiving his Ph.D., he worked as a Principal Research Engineer at New & Renewable Energy Research Center of Korean Register of Shipping from 2006 to 2013. He was a Head of Wind Energy Business Group at Innovation KR from 2013 to 2014. He is currently working at Faculty of Wind Energy Engineering of JEJU National University as an Assistant Professor from 2014. His research interests include wind energy, ocean energy converters and CAE application for engineering simulation. 

 

About The Author

Hyunseok Oh received his B.S. in Mechanical Engineering from JEJU National University in 2009 and M.S. from the same university in 2011. After receiving his M.S, he worked as a Principal Research Engineer at Korean Register of Shipping from 2011. He is currently a Ph.D. candidate at JEJU National University, where his research interests include power performance uncertainty analysis and load measurement of large wind turbines.

 

 

 

 

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Renewable Energy Global Innovations features: Assessment of grouted samples from monopile wind turbine foundations using combined non-destructive techniques

About The Author

Mr Iliopoulos is a graduate mechanical engineer of the National Technical University of Athens, Greece. Currently, he is a PhD student of the Vrije Universiteit Brussel (VUB)focusing on the development of modal based techniques for response estimation and fatigue assessment of offshore wind turbines.  

Journal Reference

Construction and Building Materials,  8 December 2015.

A.N. Iliopoulos1 D. Van Hemelrijck1, J. Vlassenbroeck2, D.G. Aggelis1

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1. Vrije Universiteit Brussel, Department of Mechanics of Materials and Constructions, Pleinlaan 2, B-1050 Brussels, Belgium
2. Inside Matters NV, Sylvain Van der Guchtlaan 24, 9300 Aalst, Belgium

Abstract

The vast majority of offshore wind farms uses wind turbines on monopile foundations for cost effective designs. These foundations are complex structures consisting of steel and a high strength cementitious grout that fills the annulus between the two concentric steel pipes known as monopile and transition piece. The grouted connection is potentially prone to structural failures when subjected to harsh offshore conditions due to combinations of extreme wind and wave excitations. Already grouting failures related to slippage of the transition piece relative to the monopile due to weakening of the adhesion between the grout and the steel have been observed at several windfarms during the construction phase. Therefore, a thorough investigation of the grouted connection is of utmost importance. In this study, a large population of cementitious cores were sampled from as many as four offshore wind turbines. The samples were subjected to Ultrasonic Pulse velocity (UPV) non-destructive testing (NDT) and compression testing while a smaller set of samples was subjected to X-ray analysis as well. This paper presents the results of the combined use of the UPV and X-ray techniques as well as correlations with compressive strength results and critically discusses the possibility of using the techniques for in situ application. To the authors’ knowledge it is the first time that these techniques are applied for assessment of the grouted connection of offshore wind turbines on monopile foundations.

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Read more research excellence studies on: Renewable Energy Global Innovations (http://ift.tt/21cCPA4)