The wind industry seeks to design wind turbines to maximize energy production and increase fatigue life. To achieve this goal, we must design wind turbines to extract maximum energy and reduce component and system loads. This paper applies modern state-space control design methods to a two-bladed teetering-hub upwind machine located at the National Wind Technology Center. The design objective is to regulate turbine speed in region 3 (above rated wind speed) and enhance damping in several low-damped flexible modes of the turbine. The controls approach is based on the Disturbance Accommodating Control method and provides accountability for wind-speed disturbances. First, controls are designed with the single control input rotor collective pitch to stabilize the first drive-train torsion as well as the tower first fore-aft bending modes. Generator torque is then incorporated as an additional control input. This reduces some of the demand placed on the rotor collective pitch control system and enhances first drive train torsion mode damping. Individual blade pitch control is then used to attenuate wind disturbances having spatial variation over the rotor and effectively reduces blade flap deflections caused by wind shear.

Issue Section:
Technical Papers
Keywords:
wind turbines, rotors, machine control, damping, torsion, control system synthesis, state-space methods, torque control
Topics:
Blades, Damping, Design, Generators, Rotors, Torsion, Trains, Turbines, Wind, Control equipment, Torque, Control systems, Stress, Wind velocity, Torque control, Wind turbines, Machinery, Wind shear
1.
Hinrichsen
,
E. N.
,
1984
, “
Controls for Variable Pitch Wind Turbine Generators
,”
IEEE Trans. Power Appar. Syst.
,
103
, pp.
886
–
892
.
2.
Barton, R. S., Bowler, C. E. J., and Piwko, R. J., 1979, Control and Stabilization of the NASA/DOE MOD-1 Two Megawatt Wind Turbine Generator, American Chemical Society, pp. 325–330.
3.
Mattson, S. E., 1984, “Modeling and Control of Large Horizontal Axis Wind Power Plants,” Ph.D thesis. Lund, Sweden: Department of Automatic Control, Lund Institute of Technology.
4.
Liebst
,
B. S.
,
1983
, “Pitch Control System for Large Scale Wind Turbines,” 7, pp. 182–192.
5.
Wright, A. D., 2003, “Control Design for Flexible Wind Turbines,” Ph.D Thesis, University of Colorado, Department of Aerospace Engineering Sciences.
6.
Bossanyi, E. A., 2000, “Developments in Closed-Loop Controller Design for Wind Turbines,” Proceedings of the 2000 ASME Wind Energy Symposium, Reno, NV, 10–13 January, pp. 64–74.
7.
Johnson, C. D., 1976, “Theory of Disturbance Accommodating Controllers,” in Advances in Control and Dynamic Systems, edited by C. T. Leondes, Academic Press, New York, San Francisco, and London, Vol. 12, pp. 387–489.
8.
Stol, K., Rigney, B., and Balas, M., 2000, “Disturbance Accommodating Control of a Variable-Speed Turbine Using a Symbolic Dynamics Structural Model,” Proceedings of the 2000 ASME Wind Energy Symposium, Reno, NV, 10–13 January, pp. 84–90.
9.
Wright, A. D. and Balas, M., 2002, “Design of State-Space-Based Control Algorithms for Wind Turbine Speed Regulation,” Proceeding of the 2002 ASME Wind Energy Symposium, Reno, NV, 14–17 January.
10.
Stol, K., and Balas, M., 2002, “Periodic Disturbance Accommodating Control for Speed Regulation of Wind Turbines,” Proceeding of the 2002 ASME Wind Energy Symposium, Reno, NV, 14–17 January, pp. 310–320.
11.
Stol, K., 2001, “Dynamics Modeling and Periodic Control of Horizontal-Axis Wind Turbines,” Ph.D thesis. University of Colorado, Department of Aerospace Engineering Sciences.
12.
Jonkman, J. M., and Buhl, M. L., 2004, FAST User’s Guide. NREL Report NREL/EL-500-29798. National Renewable Energy Laboratory, Golden, CO.
13.
Balas
,
M. J.
,
1980
, “
Disturbance Accommodating Controllers for Distributed Parameter Systems: An Introduction
,”
J. Interdisciplinary Modeling Simulation
,
pp.
63
–
81
.
14.
Balas, M. J., 1990, “Active Control of Persistent Disturbances in Large Precision Aerospace Structures,” SPIE Cont., Orlando, FL, April.
15.
Balas, M. J., Lee, Y. J., and Kendall, L., 1998, “Disturbance Tracking Control Theory with Application to Horizontal Axis Wind Turbines.” Proceedings of the 1998 ASME Wind Energy Symposium, Reno, NV, 12–15 January, pp. 95–99.
16.
Balas, M. J., Lee, Y. J., and Kendall, L., 1998, “Disturbance Tracking Control Theory with Application to Horizontal Axis Wind Turbines.” Proceedings of the 1998 ASME Wind Energy Symposium, Reno, NV, 12–15 January, pp. 95–99.
17.
Wright, A. D., and Balas, M., 2003, “Design of Modern Controls for the Controlled Advanced Research Turbine,” Proceedings of the 2003 ASME Wind Energy Symposium, Reno, NV, 6–9 January, pp. 304–316.
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