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Delegates are invited to meet and discuss with the poster presenters during the poster presentation sessions between 10:30-11:30 and 16:00-17:00 on Thursday, 19 November 2015.

Lead Session Chair:
Stephan Barth, ForWind - Center for Wind Energy Research, Germany
Atsutoshi Muto The Japan Steel Works, Ltd., Japan
Co-authors:
Atsutoshi Muto (1) F Jun Suzuki (1) Makoto Iida (2) Chuichi Arakawa (2)
(1) The Japan Steel Works, Ltd., Muroran, Japan (2) The University of Tokyo, Tokyo, Japan

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Presenter's biography

Biographies are supplied directly by presenters at EWEA 2015 and are published here unedited

Mr. Muto is a manager of research laboratory of The Japan Steel Works ltd., wind turbine manufacturer in Japan. He is responsible for an evaluation of loads working on a wind turbine, power performance, a site assessment for windfarm installed on complex terrain and so on. His researches are based on fluid dynamics and structural mechanics.


Poster

Poster Download poster (16.71 MB)

Abstract

The study of wind turbine fatigue load evaluation focusing on wind spectral

Introduction

It is thought that load fluctuation in fatigue loading evaluation of wind turbine differs by spectral characteristics of an inflow wind. Because it agrees to Gaussian distribution in flat terrain, it is taken into account in current standard. But it is known that spectral characteristics changes in complex terrain, and therefore it cannot be applied to evaluation in complex terrain adequately. In this study, the effect of wind spectral characteristics to wind turbine load are evaluated and discussed.

Approach

In this study, the three dimensions flow fields which have different spectral characteristics are produced, as inflow wind to wind turbine, with wind generation software TurbSim developed by NREL. And dynamic analyses are carried out with Bladed developed by DNV GL to evaluate fatigue loading of each part of wind turbine. As other parameters, wind velocity, turbulence intensity and yaw error are varied, and design load case (DLC) 1.2 analyses are carried out.

Main body of abstract

As a result of dynamic analysis by Bladed, it is confirmed that fatigue loading of each wind turbine part decreased when a spectral peak shifted to high frequency side by complex terrain. And it is also confirmed that variation of fatigue loading tend to be small in low wind speed area less than rated wind speed, while it is large in high wind speed area above rated wind speed. It is because that ratio of high frequency component relatively increases by peak shift to high frequency, and it is thought the frequency component that wind turbine part like tower and blades cannot respond increased.

Conclusion

In order to evaluate the influence of wind spectral characteristics changes in complex terrain to fatigue loading of each wind turbine part, dynamic analyses are carried out. As a result, it is confirmed that fatigue loading of each wind turbine part decreased when a spectral peak shifted to high frequency side, and it increased when a spectral peak shifted to low frequency side. This is caused by responsibility of each wind turbine part, and it is thought that the similar tendency is obtained from other wind turbine when its scale is same level.


Learning objectives
These results submit significance of taking wind spectral characteristics into consideration in evaluation of wind turbine construction site. Especially, in complex terrain, it is thought that accuracy of fatigue loading evaluation can be improved by taking these results into consideration, when spectral evaluation is possible by observation or numerical analysis.