Wind Loads of 5 MW Horizontal-Axis Wind Turbine Rotor in Parked Condition

운전정지 조건에서 5 MW 수평축 풍력터빈 로터의 풍하중 해석

  • Received : 2018.11.06
  • Accepted : 2018.11.26
  • Published : 2018.12.31

Abstract

In this study, wind loads exerted on the offshore wind turbine rotor in parked condition were predicted with variations of wind speeds, yaw angles, azimuth angle, pitch angles, and power of the atmospheric boundary layer profile. The calculated wind loads using blade element theorem were compared with those of estimated aerodynamic loads for the simplified blade shape. Wind loads for an NREL's 5 MW scaled offshore wind turbine rotor were also compared with those of NREL's FAST results for more verification. All of the 6-component wind loads including forces and moments along the three axis were represented on a non-rotating coordinate system fixed at the apex of rotor hub. The calculated wind loads are applicable for the dynamic analysis of the wind turbine system, or obtaining the over-turning moment at the foundation of support structure for wind turbine system.

본 연구에서는 운전 정지 상태로 회전하지 않는 수평축 해상 풍력터빈 로터에서 발생하는 풍하중을 풍속, 요 각도, 방위각, 피치 각도를 달리하면서 대기경계층 내에서 작동하는 조건으로 평가하였다. 하중 예측 결과의 검증을 위해 단순화 한 블레이드 형상에 대한 블레이드 요소이론과 단순 계산치를 이용하여 얻어낸 공력 하중을 상호 비교하였으며, 코드와 비틀림 각도가 블레이드 스팬 방향에 따라 변하는 NREL 5 MW급 대형풍력터빈 로터에 대해서는 NREL에서 개발한 FAST 해석 결과와 본 연구의 해석 결과를 비교함으로써 해석 결과의 정확도를 검증하였다. 로터의 하중은 허브 중심을 원점으로 하는 고정된 3축 좌표계에 대해서 힘과 모멘트로 표현되는 6분력 하중으로 나타내었다. 따라서 이 결과는 풍력터빈 시스템의 동적 거동 해석과 로터에서 발생되는 전도 모멘트를 견디기 위해 필요한 지지 구조물의 기초하중 자료로 적용할 수 있다.

Keywords

Acknowledgement

Grant : 풍력발전시스템 상태감시 진단시스템 개발

Supported by : 한국에너지기술평가원(KETEP)

References

  1. Seo, Y.-H., Kim, S. R. and Kim, B.-K., "Dynamic modeling of a offshore wind turbine with a supporting structure with suction buckets for prediction of natural frequencies," J. of Wind Energy, Vol. 7, No. 2 pp. 29-34, 2016. https://doi.org/10.33519/kwea.2016.7.2.004
  2. Abdelkarder, A., Aly, A. M., Rezaee, M., Bitsuamlak, G. T., and El Naggar, M. H., "On the evaluation of wind loads for wind turbines' foundation design: Experimental and numerical investigations," The Structural Design of Tall and Special Buildings, Vol. 26, No. 9 pp. 2017.
  3. Jonkman, J. M., and Buhl Jr., M. L., "FAST User's Guide," Technical Report, NREL/EL-500-38230, Aug. 2005.
  4. Lin, T.-Y., and Quemener, Y., "Extreme Typhoon loads effect on the structural response of offshore meteorological mast and wind turbine," OMAE2016-55008, Proc. ASME 35th International Conference on Ocean, Offshore and Arctic Engineering, Busan Korea, 2016.
  5. Totsuka, Y., Immamura, H., and Yde, A., "Dynamic behavior of parked wind turbine at extreme wind speed," 1st International Symposium on Flutter and Its Applications, 2016.
  6. IEC61400-3:2009, Wind turbines - Part 3: Design requirements for offshore wind turbines. International Electrotechnical Commission, 2009.
  7. Glauert, H., "The elements of airfoil and airscrew theory. Cambridge University Press, New York, 1926.
  8. Ryu, K. W., Kang, S. H., Seo, Y. H., and Lee, W. R., "Prediction of aerodynamic loads for NREL Phase VI wind Turbine blade in yawed condition," Int'l J. of Aeronautical and Space Sci. Vol. 72, No. 2, pp.157-166, 2016.
  9. Jonkman, J. M., Hayman, G. J., Jonkman, B. J., Damiani, R. R., Murray, R. E., "AeroDyn v15 User's Guide and Theory Manual," Technical Report, National Renewable Energy Laboratory, 2017.
  10. Oye, S., "Unsteady wake effects caused by pitch-angle changes," IEA R&D WECS Joint Action on Aerodynamics of Wind Turbines, Oct. 1986.
  11. Jonkman, J. M., Butterfield, S., Musial, W. and Scott, S. "Definition of a 5-MW reference wind turbine for offshore system development," Technical Report, NREL/TP-500-38060, Feb. 2009.
  12. IEC-61400-1, Wind Turbine Generator Systems, Part 1: Safety requirements. International Electrotechnical Commission, Geneva, Swiss, 2005.
  13. Kooijman, H. J. T., Lindenburg, C., Winkelaar, D., and van der Hooft, E. L., "DOWEC 6 MW Pre-Design: Aero-elastic modeling of the DOWEC 6 MW pre-design in Phatas," DOWEC Dutch Offshore Wind Energy Converter 1997-2003 Public Reports [CD-ROM], DOWEC 10046_ 009, ECN-CX--01-135, Petten, the Netherlands: Energy Research Center of the Netherlands, September 2003.
  14. Viterna, L. A., and Corrigan, R. D., "Fixed pitch rotor performance of large horizontal axis wind turbines," Proceedings, Workshop on Large Horizontal Axis Wind Turbine, NASA, P-2203, DOE Publication. CONF-810752, Cleveland, OH: NASA Lewis Research Center, pp. 69-85, 1981.
  15. DNV, "Environmental conditions and environmental loads," DNV-RPC205, Oct. 2010.