Control of Wind Turbines: Approaches, challenges, and recent developments

IEEE Control Systems

Volumn 31, Issue 2, 2011, Pages 44-62

  Pao, Lucy Y ^a   Johnson, Kathryn E ^a  

^a NONE

Author keywords

[No Author keywords available]

Indexed keywords

AVERAGE RATE; CONTROL OF WIND TURBINES; ENERGY SHORTAGES; ENVIRONMENTALLY-FRIENDLY; INSTALLED CAPACITY; INTERDISCIPLINARY FIELDS; WIND ENERGY;

WIND TURBINES;

WIND POWER;

EID: 79952916273     PISSN: 1066033X     EISSN: None     Source Type: Journal    
DOI: 10.1109/MCS.2010.939962     Document Type: Article

References (120)

1. E. A. Bossanyi “Wind turbine control for load reduction,” Wind Energy, vol. 6, pp. 229–244, 2003.
2. E. A. Bossanyi “Further load reductions with individual pitch control,” Wind Energy, vol. 8, pp. 481–485, 2005.
3. M. Balas, Y. J. Lee, and L. Kendall, “Disturbance tracking control theory with application to horizontal axis wind turbines,” in Proc. AIAA/ASME Wind Energy Symp., Reno, NV, 1998, pp. 95–99.
4. H. Namik and K. Stol, “Disturbance accommodating control of floating offshore wind turbines,” in Proc. AIAA/ASME Wind Energy Symp., Orlando, FL, 2009, AIAA 2009–483.
5. G. A. Parker and C. D. Johnson, “Improved speed regulation and mitigation of drive-train torsion fatigue in flexible wind turbines, using disturbance utilization control: Part one,” in Proc. 41st Southeastern Symp. System Theory, Tullahoma, TN, 2009, pp. 171–176.
6. C. D. Johnson, “Theory of disturbance-accommodating controllers,” in Control and Dynamic Systems, C. T. Leondes, Ed. New York: McGraw-Hill, 1976, vol. XII.
7. K. Z. Ostergaard, J. Stoustrup, and P. Brath “Linear parameter varying control of wind turbines covering both partial load and full load conditions,” Int. J. Robust Nonlinear Control, vol. 19, pp. 92–116, 2009.
8. A. Kumar and K. Stol “Simulating feedback linearization control of wind turbines using high-order models,” Wind Energy, vol. 13, no. 5, pp. 419–432, 2010.
9. M. A. Rotea, M. A. Lackner, and R. Saheba, “Active structural control of offshore wind turbines,” in Proc. AIAA/ASME Wind Energy Symp., Orlando, FL, 2010, AIAA 2010–1000.
10. M. A. Lackner and M. A. Rotea. (2011). Passive structural control of offshore wind turbines. Wind Energy, vol. 14 [Online]. Available: http://onlinelibrary.wiley.com/doi/10.1002/we.426/full
11. S. Kanev and T. van Engelen “Wind turbine extreme gust control,” Wind Energy, vol. 13, pp. 18–35, 2010.
12. A. A. Kumar and K. A. Stol, “Scheduled model predictive control of a wind turbine,” in Proc. AIAA/ASME Wind Energy Symp., Orlando, FL, 2009, AIAA 2009–481.
13. M. M. Hand, A. D. Wright, L. J. Fingersh, and M. Harris, “Advanced wind turbine controllers attenuate loads when upwind velocity measurements are inputs,” in Proc. AIAA/ASME Wind Energy Symp., Reno, NV, 2006, AIAA 2006–603.
14. J. H. Laks, L. Y. Pao, and A. Wright, “Combined feedforward/feedback control of wind turbines to reduce blade flap bending moments,” in Proc. AIAA/ASME Wind Energy Symp., Orlando, FL, 2009, AIAA 2009–687.
15. K. Selvam, S. Kanev, J. W. van Wingerden, T. van Engelen, and M. Verhaegen, “Feedback-feedforward individual pitch control for wind turbine load reduction,” Int. J. Robust Nonlinear Control, vol. 19, no. 1, pp. 72–91,2009.
16. D. Schlipf and M. Kuhn, “Prospects of a collective pitch control by means of predictive disturbance compensation assisted by wind speed measurements,” in Proc. DEWEK (German Wind Energy Conf.), 2008, pp. 1–4.
17. F. Dunne, L. Y. Pao, A. Wright, B. Jonkman, and N. Kelley, “Combining standard feedback controllers with feedforward blade pitch control for load mitigation in wind turbines,” in Proc. AIAA/ASME Wind Energy Symp., Orlando, FL, 2010, AIAA 2010–250.
18. J. H. Laks, L. Y. Pao, E. Simley, A. Wright, N. Kelley, and B. Jonkman, “Model predictive control using preview measurements from lidar,” in Proc. AIAA/ASME Wind Energy Symp., Orlando, FL, Jan. 2011, AIAA-2011-813, pp. 1–20.
19. E. Simley, L. Y. Pao, R. Frehlich, B. Jonkman, and N. Kelley, “Analysis of wind speed measurements using coherent lidar for wind preview control,” in Proc. AIAA/ASME Wind Energy Symp., Orlando, FL, Jan. 2011, AIAA-2011-263, pp. 1–16.
20. 2 coherent laser systems,” Proc. IEEE, vol. 84, no. 2, pp. 181–204, 1996.
21. M. A. Lackner and G. A. M. van Kuik “A comparison of smart rotor control approaches using trailing edge flaps and individual pitch control,” Wind Energy (Special Issue: Smart Blades), vol. 13, no. 2–3, pp. 117–134, 2010.
22. S. Johnson, J. Baker, C. van Dam, and D. Berg “An overview of active load control techniques for wind turbines with an emphasis on microtabs,” Wind Energy, vol. 13, pp. 239–253, 2010.
23. V. Maldonado, J. Farnsworth, W. Gressick, and M. Amitay “Active control of flow separation and structural vibrations of wind turbine blades,” Wind Energy (Special Issue: Smart Blades), vol. 13, no. 2–3, pp. 221–237, 2010.
24. T. J. McCoy and D. A. Griffin “Control of rotor geometry and aerodynamics: Retractable blades and advanced concepts,” Wind Eng., vol. 32, no. 1, pp. 13–26, 2008.
25. J. Rice and M. Verhaegen “Robust and distributed control of a smart blade,” Wind Energy, vol. 13, pp. 103–116, 2010.
26. S. Bhowmik, R. Spee, and J. Enslin “Performance optimization for doubly-fed wind power generation systems,” IEEE Trans. Ind. Applicat., vol. 35, no. 4, pp. 949–958, 1999.
27. A. M. Howlander, N. Urasaki, K. Uchida, A. Yona, T. Senjyu, C.-H. Kim, and A. Y. Saber “Parameter identification of wind turbine for maximum power-point tracking control,” Electric Power Compon. Syst., vol. 38, pp. 603–614, 2010.
28. T. Senjyu, Y. Ochi, Y. Kikunaga, M. Tokudome, A. Yona, E. B. Muhando, N. Urasaki, and T. Funabashi “Sensor-less maximum power point tracking control for wind generation system with squirrel-cage induction generator,” Renewable Energy, vol. 34, pp. 994–999, 2009.
29. A. Kusiak, W. Li, and Z. Song “Dynamic control of wind turbines,” Renewable Energy, vol. 35, pp. 456–463, 2010.
30. W.-M. Lin and C.-M. Hong “Intelligent approach to maximum power point tracking control strategy for variable-speed wind turbine generation system,” Energy, vol. 35, pp. 2440–2447, 2010.
31. J. Brahmi, L. Krichen, and A. Ouali “A comparative study between three sensorless control strategies for PMSG in wind energy conversion system,” Appl. Energy, vol. 86, pp. 1565–1573, 2009.
32. M. Narayana, G. Putrus, M. Jovanovic, and M. P. S. Leung, “Predictive control of wind turbines by considering wind speed forecasting techniques,” in Proc. 44th International Universities Power Engineering Conf., UPEC2009, Glasgow, Scotland, 2009, pp. 1–4.
33. M. Krstic, “Performance improvement and limitations in extremum seeking control,” Syst. Control Lett., vol. 39, no. 5, pp. 313–326, 2000.
34. M. Krstic and H. H. Wang “Stability of extremum seeking feedback for general nonlinear dynamic systems,” Automatica, vol. 36, no. 4, pp. 595–601, 2000.
35. J. Creaby, Y. Li, and J. E. Seem “Maximizing wind turbine energy capture using multivariable extremum seeking control,” Wind Eng., vol. 33, no. 4, pp. 361–388, 2009.
36. N. A. Cutululis, E. Ceanga, A. D. Hansen, and P. Sorensen “Robust multi-model control of an autonomous wind power system,” Wind Energy, vol. 9, pp. 399–419, 2006.
37. H. Geng and G. Yang “Output power control for variable-speed variable-pitch wind generation systems,” IEEE Trans. Energy Conversion, vol. 25, no. 2, pp. 494–503, June 2010.
38. C. Vlad, I. Munteanu, A. I. Bratcu, and E. Ceanga “Output power maximization of low-power wind energy conversion systems revisited: Possible control solutions,” Energy Convers. Manage., vol. 51, pp. 305–310, 2010.
39. E. Muhando, T. Senjyu, E. Omine, T. Funabashi, and C. Kim “Modelling-based approach for digital control design for nonlinear WECS in the power system,” Wind Energy, vol. 13, no. 6, pp. 543–557, 2010.
40. F. Stoddard, “Wind turbine blade technology: A decade of lessons learned,” in Proc. World Renewable Energy Congr., Reading, England, 1990, pp. 1570–1578.
41. X. Wang. (2008). Convective heat transfer and experimental icing aerodynamics of wind turbine blades, Ph.D. dissertation, Univ. Manitoba [Online]. Available: http://mspace.lib.umanitoba.ca/handle/1993/3082
42. T. Laakso, I. Baring-Gould, M. Durstewitz, R. Horbaty, A. Lacroix, E. Peltola, G. Ronsten, L. Tallhaug, and T. Wallenius. (2009). State-of-the-art of wind energy in cold climates. Int. Energy Agency Report [Online]. Available: http://arcticwind.vtt.fi/
43. S. Barber, Y. Wang, S. Jafari, N. Chokani, and R. S. Abhari, “The effect of icing on wind turbine performance and aerodynamics,” in Proc. European Wind Energy Conf., Warsaw, Poland, 2010, pp. 1–11.
44. M. Liu, M. Yocke, and T. Myers “Mathematical model for the analysis of wind-turbine wakes,” J. Energy, vol. 7, pp. 73–78, 1983.
45. M. Steinbuch, W. W. de Boer, O. H. Bosgra, S. A. W. M. Peters, and J. Ploeg, “Optimal control of wind power plants,” J. Wind Eng. Ind. Aerodyn., vol. 27, pp. 237–246, 1988.
46. S. Frandsen “On the wind speed reduction in the center of large clusters of wind turbines,” J. Wind Eng. Ind. Aerodyn., vol. 39, pp. 251–265, 1992.
47. L. M. Fernandez, C. A. Garcia, and F. Jurado “Comparative study on the performance of control systems for doubly fed induction generator (DFIG) wind turbines operating with power regulation,” Energy, vol. 33, pp. 1438–1452, 2008.
48. A. D. Hansen, P. Srensen, F. lov, and F. Blaabjerg “Centralised power control of wind farm with doubly fed induction generators,” Renewable Energy, vol. 31, pp. 935–951, 2006.
49. W. Qiao, G. K. Venayagamoorthy, and R. G. Harley “Real-time implementation of a statcom on a wind farm equipped with doubly fed induction generators,” IEEE Trans. Ind. Applicat., vol. 45, no. 1, pp. 98–107, 2009.
50. C. Jauch, J. Matevosyan, T. Ackermann, and S. Bolik “International comparison of requirements for connection of wind turbines to power systems,” Wind Energy, vol. 8, no. 3, pp. 295–306, 2005.
51. I. Erlich and M. Wilch, “Primary frequency control by wind turbines,” in Proc. Power and Energy Society General Meeting, Minneapolis, MN, 2010, pp. 1–8.
52. G. C. Tarnowski, P. C. Kjaer, S. Dalsgaard, and A. Nyborg, “Regulation and frequency response service capability of modern wind power plants,” in Proc. Power and Energy Society General Meeting, Minneapolis, MN, 2010, pp. 1–8.
53. N. W. Miller and K. Clark, “Advanced controls enable wind plants to provide ancillary services,” in Proc. Power and Energy Society General Meeting, Minneapolis, MN, 2010, pp. 1–8.
54. C. F. Moyano and J. A. Pecas Lopes “An optimization approach for wind turbine commitment and dispatch in a wind park,” Electric Power Syst. Res., vol. 79, pp. 71–79, 2009.
55. J. Kristoffersen “The Horns Rev wind farm and the operational experience with the wind farm main controller,” Revue E, vol. 122, pp. 26–31, 2006.
56. R. D. Fernandez, P. E. Battaiotto, and R. J. Mantz “Wind farm nonlinear control for damping electromechanical oscillations of power systems,” Renewable Energy, vol. 33, pp. 2258–2265, 2008.
57. J. L. Rodriguez-Amenedo, S. Arnaltes, and M. A. Rodriguez “Operation and coordinated control of fixed and variable speed wind farms,” Renewable Energy, vol. 33, pp. 406–414, 2008.
58. E. Muljadi and C. P. Butterfield. (2004). Wind farm power system model development. Proc. World Renewable Energy Conf., Denver, CO, pp. 1–8 [Online]. Available: http://www.nrel.gov/docs/fy04osti/36199.pdf
59. E. Muljadi and B. Parsons. (2006). Comparing single and multiple turbine representations in a wind farm simulation. Proc. European Wind Energy Conf., Athens, Greece, pp. 1–13 [Online]. Available: http://www.nrel.gov/docs/fy06osti/39510.pdf
60. M. B. Christiansen and C. B. Hasager “Wake effects of large offshore wind farms identified from satellite SAR,” Remote Sens. Environ., vol. 98, pp. 251–268, 2005.
61. K. E. Johnsson and N. Thomas, “Wind farm control: Addressing the aerodynamic interaction among wind turbines,” in Proc. American Control Conf., St. Louis, MO, 2009, pp. 2104–2109.
62. Arnejohs. Windpark in Galicia (2011). [Online]. Available: http://upload.wikimedia.Org/wikipedia/commons/0/0c/Windpark_Galicia.jpg
63. A. R. Henderson, C. Morgan, B. Smith, H. C. Sorenson, R. J. Barthelmie, and B. Boesmans “Offshore wind energy in Europe—A review of the state-of-the-art,” Wind Energy, vol. 6, no. 1, pp. 35–52, 2003.
64. W. Musial and S. Butterfield. (2004). Future for offshore wind energy development in the United States. Proc. Energy Ocean [On-line]. Available: http://oce.uri.edu/oce495s1/2008/Musial%20et%20al%202004.pdf
65. J. Jonkman. (2007). Dynamics modeling and loads analysis of an offshore floating wind turbine, Ph.D. dissertation, Univ. Colorado at Boulder [Online]. Available: http://www.nrel.gov/docs/fy08osti/41958.pdf
66. J. Jonkman and D. Matha. (2009). A quantitative comparison of the responses of three floating platform concepts. Proc. European Offshore Wind Conf. Expo., Stockholm, Sweden [Online]. Available: http://www.nrel.gov/docs/fy10osti/46726.pdf
67. J. Jonkman “Dynamics of offshore floating wind turbines—Model development and verification,” Wind Energy, vol. 12, no. 5, pp. 459–492, 2009.
68. J. Jonkman and P. D. Sclavounos, “Development of fully coupled aeroelastic and hydrodynamic models for offshore wind turbines,” in Proc. AIAA/ASME Wind Energy Symp., Reno, NV, 2006, AIAA 2006–995.
69. H. Namik, K. Stol, and J. Jonkman, “State-space control of tower motion for deepwater floating offshore wind turbines,” in Proc. AIAA/ASME Wind Energy Symp., Reno, NV, 2008, AIAA 2008–1307.
70. H. Namik and K. Stol, “Individual blade pitch control of a floating offshore wind turbine on a tension leg platform,” in Proc. AIAA/ASME Wind Energy Symp., Orlando, FL, 2010, AIAA 2010–999.
71. World Wind Energy Association. (2010). World wind energy installed capacity [Online]. Available: http://www.wwindea.org
72. U.S. Department of Energy Office of Energy Efficiency and Renewable Energy. (2010). U.S. installed wind capacity and wind project locations [On-line]. Available: http://www.windpoweringamerica.gov/wind_installed_capacity. asp
73. J. M. Roney. (2010). Wind power soared past 150,000 megawatts in 2009 [Online]. Available: http://www.earth-policy.org/index.php?/indicators/wind_power_2010
74. U.S. Department of Energy Office of Energy Efficiency and Renewable Energy. (2008). 20% wind energy by 2030 [Online]. Available: http://wwwl.eere.energy.gov/windandhydro/pdfs/41869.pdf
75. J. F. Manwell, J. G. McGowan, and A. L. Rogers, Wind Energy Explained: Theory, Design, and Application. West Sussex, England: Wiley, 2002.
76. T. Burton, D. Sharpe, N. Jenkins, and E. Bossanyi, Wind Energy Handbook. West Sussex, England: Wiley, 2001.
77. K. E. Johnson. (2004). Adaptive torque control of variable speed wind turbines, Ph.D. dissertation, Univ. Colorado at Boulder [Online]. Available: http://www.nrel.gov/docs/fy04osti/36265.pdf
78. A. Betz, Introduction to the Theory of Flow Machines. Oxford: Pergamon, 1966.
79. Danish Wind Industry Association. (2003). Turbines: How many blades [Online]. Available: http://www.talentfactory.dk/en/tour/design/concepts.htm
80. N. D. Kelley, B. J. Jonkman, and G. N. Scott. (2006). The great plains turbulence environment: Its origins, impact, and simulation. Proc. AWEA's WindPower Conf., Pittsburgh, PA [Online]. Available: http://www.nrel.gov/docs/fy07osti/40176.pdf
81. M. Harris, M. Hand, and A. Wright. (2006). Lidar for turbine control, NREL, Golden, CO, NREL Tech. Rep. TP-500-39154 [Online]. Available: http://www.nrel.gov/docs/fy06osti/39154.pdf
82. M. Hand. (2003). Mitigation of wind turbine/vortex interaction using disturbance accommodating control, Ph.D. dissertation, Univ. Colorado at Boulder [Online]. Available: http://www.nrel.gov/docs/fy04osti/35172. pdf
83. N. D. Kelley, R. M. Osgood, J. T. Bialasiewicz, and A. Jakubowski “Using wavelet analysis to assess turbulence/rotor interactions,” Wind Energy, vol. 3, pp. 121–134, 2000.
84. R. Frehlich and N. D. Kelley “Measurements of wind and turbulence profiles with scanning Doppler LIDAR for wind energy applications,” IEEE J. Select. Topics Appl. Earth Observations Remote Sens., vol. 1, no. 1, pp. 42–47, 2008.
85. T. Mikkelsen, K. Hansen, N. Angelou, M. Sjoholm, M. Harris, P. Hadley, R. Scullion, G. Ellis, and G. Vives, “LIDAR wind speed measurements from a rotating spinner,” in Proc. European Wind Energy Conf., Warsaw, Poland, 2010, pp. 1–8.
86. D. Schlipf, D. Trabucchi, O. Bischoff, M. Hofsass, J. Mann, T. Mikkelsen, A. Rettenmeier, J. J. Trujillo, and M. Kuhn, “Testing of frozen turbulence hypothesis for wind turbine applications with a scanning LIDAR system,” in Proc. Int. Symp. Advancement of Boundary Layer Remote Sensing, Paris, France, 2010, pp. 1–4.
87. M. Sjoholm, T. Mikkelsen, L. Kristensen, J. Mann, P. Kirkegaard, S. Kapp, D. Schlipf, and J. J. Trujillo, “Spectral analysis of wind turbulence measured by a Doppler LIDAR for velocity fine structure and coherence studies,” in Proc. Int. Symp. Advancement of Boundary Layer Remote Sensing, Paris, France, 2010, pp. 1–4.
88. M. Hand and M. Balas, “Blade load mitigation control design for a wind turbine operating in the path of vortices,” Wind Energy, vol. 10, pp. 339–355, 2007.
89. Y. Amirat, M. E. H. Benbouzid, E. Al-Ahmar, B. Bensaker, and S. Turri “A brief status on condition monitoring and fault diagnosis in wind energy conversion systems,” Renewable Sustainable Energy Rev., vol. 13, pp. 2629–2636, 2009.
90. Z. Hameed, S. H. Ahn, and Y. M. Cho, “Practical aspects of a condition monitoring system for a wind turbine with emphasis on its design, system architecture, testing and installation,” Renewable Energy, vol. 35, pp. 879–894, 2010.
91. K. E. Johnson, L. Fingersh, and A. Wright, “Controls advanced research turbine: Lessons learned during advanced controls testing,” NREL, Golden, CO, NREL Tech. Rep. TP-500-38130, 2005.
92. F. D. Bianchi, H. De Battista, and R. J. Mantz, Wind Turbine Control Systems: Principles, Modelling and Gain Scheduling Design. New York: Springer-Verlag, 2006.
93. E. A. Bossanyi, GH Bladed Theory Manual, Garrad Hassan and Partners Ltd., Bristol, U.K., 2003.
94. J. Jonkman and M. Buhl, FAST User–s Guide, NREL/EL-500-38230, Golden, CO, 2005.
95. B. Jonkman, TurbSim User's Guide: Version 1.50, NREL/EL-500-46198, Golden, CO, 2009.
96. T. J. Larsen and A. M. Hansen, How 2 HAWC2, The User's Manual, Riso-R-1597, Riso Nat. Lab., Tech. Univ. Denmark, Roskilde, Denmark, 2007.
97. P. Harris and P. Migliore, “Semi-empirical aeroacoustic noise prediction code for wind turbines,” NREL, Golden, CO, NREL Tech. Rep. TP-500-34478, 2003.
98. P. Moriarty, “Safety factor calibration for wind turbine extreme loads,” Wind Energy, vol. 11, no. 6, pp. 601–612, 2008.
99. P. Moriarty and C. P. Butterfield, “Wind turbine modeling overview for control engineers,” in Proc. American Control Conf., St. Louis, MO, 2009, pp. 2090–2095.
100. S. Oye, “Simulations of loads on a wind turbine including turbulence,” in Proc. IEA Meeting, Stockholm, Sweden, 1991, pp. 99–105.
101. MSC.Software Corporation. (2011). Adams multibody dynamics software [Online]. Available: http://www.mscsoftware.com/Products/CAE-Tools/Adams.aspx
102. K. E. Johnson, L. Y. Pao, M. J. Balas, and L. J. Fingersh “Control of variable-speed wind turbines: Standard and adaptive techniques for maximizing energy capture,” IEEE Control Syst. Mag., vol. 26, no. 3, pp. 70–81, June 2006.
103. K. Stol and M. J. Balas, “Periodic disturbance accommodating control for speed regulation of wind turbines,” in Proc. AIAA/ASME Wind Energy Symp., Reno, NV, 2002, pp. 310–320.
104. M. M. Hand and M. J. Balas “Systematic controller design methodology for variable-speed wind turbines,” Wind Eng., vol. 24, no. 3, pp. 169–187, 2000.
105. F. Lescher, J. Y. Zhao, and A. Martinez. (2006). Multiobjective control of a pitch regulated wind turbine for mechanical load reduction. Proc. Int. Conf. Renewable Energy and Power Quality, Granada, Spain [Online]. Available: http://www.icrepq.com/papers-icrepq06.htm
106. M. Geyler and P. Caselitz “Robust multivariable pitch control design for load reduction on large wind turbines,” J. Solar Energy Eng., vol. 130, no. 3, pp. 031014-1–031014-12, 2008.
107. J. H. Laks, L. Y. Pao, and A. Wright, “Control of wind turbines: Past, present, and future,” in Proc. American Control Conf., St. Louis, MO, 2009, pp. 2096–2103.
108. J. H. Laks, L. Y. Pao, A. Wright, N. Kelley, and B. Jonkman, “Blade pitch control with preview wind measurements,” in Proc. AIAA/ASME Wind Energy Symp., Orlando, FL, 2010, AIAA 2010–251.
109. L. Fingersh and K. Johnson, “Baseline results and future plans for the NREL controls advanced research turbine,” in Proc. AIAA/ASME Wind Energy Symp., Reno, NV, 2004, pp. 87–93.
110. L. Fingersh and P. Carlin, “Results from the NREL variable-speed test bed,” in Proc. AIAA/ASME Wind Energy Symp., Reno, NV, 1998, pp. 233–237.
111. J. Freeman and M. Balas, “An investigation of variable speed horizontal-axis wind turbines using direct model-reference adaptive control,” in Proc. AIAA/ASME Wind Energy Symp., Reno, NV, 1999, pp. 66–76.
112. S. A. Frost, M. J. Balas, and A. D. Wright “Direct adaptive control of a utility-scale wind turbine for speed regulation,” Int. J. Robust Nonlinear Control (Special Issue: Wind Turbines, New Challenges and Advanced Control Solutions), vol. 19, no. 1, pp. 59–71, 2009.
113. Y. D. Song, B. Dhinakaran, and X. Bao “Variable speed control of wind turbines using nonlinear and adaptive algorithms,” J. Wind Eng. Ind. Aerodyn., vol. 85, pp. 293–308, 2000.
114. J. W. van Wingerden, I. Houtzager, F. Felici, and M. Verhaegen “Closed-loop identification of the time-varying dynamics of variable-speed wind turbines,” Int. J. Robust Nonlinear Control, vol. 19, no. 1, pp. 4–21, 2009.
115. A. M. L. Johnsen. (2011). Wind power [Online]. Available: http://www. renewableenergy.no
116. Aerospaceweb.org. (2010). Boeing 747 long-range jetliner [Online]. Available: http://www.aerospaceweb.org/aircraft/jetliner/b747
117. Steinninn. (2011). American football [Online]. Available: http://en.wikipedia.org/wiki/American_football
118. Symscape: Computational fluid dynamics for all. (2007). Darrieus vertical-axis wind turbine [Online]. Available: http://www.symscape.com/node/406
119. U.S. Department of Energy. (2010). Energy efficiency and renewable energy [Online]. Available: http://wwwl.eere.energy.gov/windandhydro/wind_how.html
120. R. Banta, Y. Pichugina, N. Kelley, B. Jonkman, and W. Brewer, “Doppler lidar measurements of the Great Plains low-level jet: Applications to wind energy,” in Proc. 14th Int. Symp. Advancement of Boundary Layer Remote Sensing, 2008, pp. 1–5.