Control of Wind Turbines and Wind Farms

Project Title: 50 MW Segmented Ultralight Morphing Rotors for Wind Energy

Investigators: Eric Loth (University of Virginia), D. Todd Griffith (Sandia National Labs), Kathryn Johnson (Colorado School of Mines), Pat Moriarty (National Renewable Energy Laboratory), Lucy Pao, and Michael Selig (University of Illinois at Urbana-Champaign)

Sponsor: Advanced Research Projects Agency - Energy

Project Duration: April 2016 - March 2019

Project Title: Previewed Disturbance Rejection with Application to the Control of Wind Turbines

Investigators: Maxim Kristalny (Technion - Israel Institute of Technology) and Lucy Y. Pao

Sponsor: US-Israel Binational Science Foundation

Project Duration: September 2013 - September 2016

Project Title: Development and Evaluation of Wind Turbine Lidar-Based Feedforward Controls

Investigator: Lucy Y. Pao

Sponsor: Department of Energy / National Renewable Energy Laboratory

Project Duration: May 2013 - September 2017

Project Title: Studying the Ability of Wind Turbines to Provide Advanced Power Control

Investigator: Lucy Y. Pao

Sponsor: Department of Energy / National Renewable Energy Laboratory

Project Duration: January 2012 - August 2016

National Renewable Energy Laboratory Technical Reports:

A. Buckspan, J. P. Aho, P. Fleming, Y. Jeong, and L. Y. Pao, "Combining Droop Curve Concepts with Control Systems for Wind Turbine Active Power Control," NREL/CP-5000-55211, June 2012.

J. P. Aho, A. Buckspan, J. Laks, P. Fleming, Y. Jeong, F. Dunne, M. Churchfield, L. Pao, and K. Johnson, " A Tutorial of Wind Turbine Control for Supporting Grid Frequency through Active Power Control," NREL/CP-5000-54605, March 2012.

Project Title: Lidar-Based Control of Wind Turbines

Investigator: Lucy Y. Pao

Advisors: Alan Wright, K. E. Johnson, and Bonnie Jonkman

Project Duration: October 2011 - December 2012

Project Title: An Innovative Approach to the Design and Control of Wind Farms

Investigators: Jason R. Marden and Lucy Y. Pao

Sponsor: Center for Research and Education in Wind

Project Duration: August 2011 - May 2013

Project Title: Development and Evaluation of Advanced Feedforward Controls for Wind Turbines

Investigator: Lucy Y. Pao

Sponsor: Department of Energy / National Renewable Energy Laboratory

Project Duration: January 2011 - July 2013

National Renewable Energy Laboratory Technical Reports:

F. Dunne, D. Schlipf, and L. Y. Pao, "Comparison of Two Independent Lidar-Based Pitch Control Designs," NREL/SR-5000-55544, 36 pages, Aug. 2012.

E. Simley and L. Y. Pao, "LIDAR Wind Speed Measurements of Evolving Wind Fields," NREL/SR-5000-55516, 41 pages, July 2012.

Project Title: Feasibility Study of Control of Novel Active Coating Materials for Preventing Icing on Wind Turbine Blades

Investigators: Lucy Y. Pao and Robert R. McLeod

Sponsor: Center for Research and Education in Wind

Project Duration: August 2010 - July 2012

Project Title: Windplant Systems Engineering Analysis and Optimization

Investigator: Lucy Y. Pao

Sponsor: Department of Energy / National Renewable Energy Laboratory

Project Duration: April 2010 - January 2011

Project Title: Offshore Wind Energy Technology and Challenges

Investigator: Lucy Y. Pao

Sponsor: Department of Energy / National Renewable Energy Laboratory

Project Duration: September 2009 - June 2010

Project Title: Lidar-Based Control of Wind Turbines: Feasibility Study

Investigators: Lucy Y. Pao and K. E. Johnson

Advisors: Alan Wright, Rod Frehlich, Bonnie Jonkman, and Neil Kelley

Project Duration: July 2009 - July 2011

Project Title: Advanced Controls for Wind Turbines

Investigator: Lucy Y. Pao

Sponsor: Department of Energy / National Renewable Energy Laboratory

Project Duration: January 2009 - July 2011

National Renewable Energy Laboratory Technical Reports:

F. Dunne, E. Simley, and L. Y. Pao, "LIDAR Wind Speed Measurement Analysis and Feedforward Blade Pitch for Load Mitigation in Wind Turbines," NREL/SR-5000-52098, 53 pages, Oct. 2011.

J. H. Laks, F. Dunne, and L. Y. Pao, "Feasibility Studies on Disturbance Feedforward Techniques to Improve Load Mitigation Performance in Wind Turbines," NREL/SR-5000-48598, 52 pages, Dec. 2010.

Project Title: Design of Lidar, Data Processing, and Control Algorithms for Optimal Wind Farm Performance

Investigators: Rod G. Frehlich and Lucy Y. Pao

Sponsor: CU/NREL Energy Initiative

Project Duration: June 2007 - December 2008

Awards and Honors:

E. Simley was a lecturer at the Summer School in Remote Sensing for Wind Energy, Roskilde, Denmark, June 2014.

E. Simley was honored with 3rd place in the 2014 IEEE New Faces of Engineering Competition.

Plenary Presentation at the IEEE Conference on Decision and Control on "Controlling Wind Energy for Utility Grid Reliability" (Thursday, December 12, 2013).

Keynote Presentation at the SICE Annual Conference (International Conference on Instrumentation, Control, Information Technology and System Integration) on "Wind Energy Control and Grid-Integration Challenges" (Monday, September 16, 2013).

PhD student Eric Simley is spending September 2013 to June 2014 at the Technical University of Denmark Department of Wind Energy on a Fulbright Fellowship.

E. Simley was a lecturer at the Summer School in Remote Sensing for Wind Energy, Roskilde, Denmark, June 2013.

Plenary Presentation at the IEEE Power and Energy Conference at Illinois on "Wind Energy Control and Grid-Related Issues" (Saturday, February 23, 2013).

Co-recipient (with Kathryn Johnson) of the IEEE Control Systems Magazine Outstanding Paper Award (December 2012).

ASME Dynamic Systems and Control Conference Plenary Talk on "Control of Wind Turbines: Accomplishments and Continuing Challenges" (Wednesday, October 17, 2012).

E. Simley was a lecturer at the Summer School in Remote Sensing for Wind Energy, Boulder, CO, June 2012.

Chinese Control and Decision Conference Distinguished Lecture on "Control of Wind Turbines: Accomplishments and Challenges" (Thursday, May 24, 2012).

ASME International Mechanical Engineering Congress and Exposition Plenary on "Control of Wind Turbines: Accomplishments and Challenges" (Monday, November 14, 2011).

Short video on "CU and National Labs Work To Harness Wind Power" featured in CU-Boulder Chancellor's August 2009 update.

Colorado Governor Bill Ritter to Kick Off Inaugural Symposium for New Colorado Wind Research Center on August 14, 2009 Visiting Scholar at the National Renewable Energy Laboratory's National Wind Technology Center, January 2009 - August 2009

Recent Publications:

D. Schlipf, E. Simley, F. Lemmer, L. Pao, P. W. Cheng, "Collective Pitch Feedforward Control of Floating Wind Turbines Using Lidar," accepted for publication in J. Ocean and Wind Energy.

P. Fleming, J. Aho, A. D. Buckspan, E. Ela, Y. Zhang, V. Gevorgian, A. Scholbrock, L. Pao, and R. Damiani, "Effects of Power Reserve Control on Wind Turbine Structural Loading," Wind Energy, to appear; first published in Wiley Online Library in Mar. 2015.

E. Simley and L. Y. Pao, "A Longitudinal Spatial Coherence Model for Wind Evolution based on Large-Eddy Simulation," Proc. American Control Conf., Chicago, IL, pp. 3708-3714, July 2015.

D. Schlipf, E. Simley, F. Lemmer, L. Pao, P. W. Cheng, "Collective Pitch Feedforward Control of Floating Wind Turbines Using Lidar," Proc. Intl. Soc. Offshore and Polar Engineers, Kona, HI, June 2015.

E. Simley and L. Y. Pao, "Evaluation of a Wind Speed Estimator for Hub-Height and Shear Components," Wind Energy, to appear; first published in Wiley Online Library in Dec. 2014.

P. M. O. Gebraad, F. W. Teeuwisse, J. W. van Wingerden, P. A. Fleming, S. D. Ruben, J. R. Marden, and L. Y. Pao, "Wind Plant Power Optimization through Yaw Control Using a Parametric Model for Wake Effects," Wind Energy, to appear; first published in Wiley Online Library in Dec. 2014.

S. Shajiee, L. Y. Pao, and R. R. McLeod, "Optimizing the Layout of Heaters for Distributed Active De-icing of Wind Turbine Blades," Wind Engineering, Vol. 38(6): 587-600, Dec. 2014.

S. Shajiee, L. Y. Pao, and R. R. McLeod, "Monitoring Ice Accumulation and Active De-Icing Control of Wind Turbine Blades," chapter in Wind Turbine Control and Monitoring, Springer, Advances in Industrial Control series, edited by N. Luo, Y. Vidal, and L. Acho, 2014, ISBN 978-3-319-08412-1.

J. Aho, L. Pao, P. Fleming, and E. Ela, "Controlling Wind Turbines for Secondary Frequency Regulation: An Analysis of AGC Capabilities under New Performance Based Compensation Policy," Proc. Wind Integration Workshop, Berlin, Germany, Nov. 2014.

L. Y. Pao, "Active Power Control of Wind Power Plants for Grid Integration," article in Encyclopedia of Systems and Control, edited by J. Baillieul and T. Samad, DOI 10.1007/978-1-4471-5102-9_272-1, Springer-Verlag London 2014.

I. P. Girsang, J. S. Dhupia, E. Muljadi, M. Singh, and L. Y. Pao, "Gearbox and Drivetrain Models to Study Dynamic Effects of Modern Wind Turbines," IEEE Trans. Industry Applications, 50(6): 3777-3786, Nov. 2014.

J. R. Marden, H. P. Young, and L. Y. Pao, "Achieving Pareto Optimality through Distributed Learning," SIAM J. Control & Optimization, 52(5): 2753-2770, Oct. 2014.

E. Simley, L. Y. Pao, P. M. O. Gebraad, and M. Churchfield, "Investigation of the Impact of the Upstream Induction Zone on LIDAR Measurement Accuracy for Wind Turbine Control Applications using Large-Eddy Simulation," Proc. Science of Making Torque from Wind, Lyngby, Denmark, 10 pages, June 2014.

P. M. O. Gebraad, F. W. Teewisse, J. W. van Wingerden, P. A. Fleming, S. D. Ruben, J. R. Marden, and L. Y. Pao, "A Data-Driven Model for Wind Plant Power Optimization by Yaw Control," Proc. American Control Conf., Portland, OR, pp. 3140-3146, June 2014.

F. Dunne, L. Y. Pao, D. Schlipf, and A. Scholbrock, "Importance of Lidar Measurement Timing Accuracy for Wind Turbine Control," Proc. American Control Conf., Portland, OR, pp. 3728-3733, June 2014.

E. Simley, L. Y. Pao, R. Frehlich, B. Jonkman, and N. Kelley. "Analysis of Light Detection and Ranging Wind Speed Measurements for Wind Turbine Control," Wind Energy, 17(3): 413-433, March 2014; first published in Wiley Online Library in Feb. 2013.

E. Simley and L. Y. Pao, "Design and Evaluation of a Wind Speed Estimator for Hub-Height and Shear Components," Proc. 9th PhD Seminar on Wind Energy in Europe, Gotland, Sweden, 5 pages, Sept. 2013.

I. Girsang, J. Dhupia, E. Muljadi, M. Singh, and L. Pao, "Gearbox and Drive-Train Models for Studying the Dynamic Effects of Modern Wind Turbines," Proc. IEEE Energy Conversion Congress & Exposition, Denver, CO, pp. 874-881, Sept. 2013. Also published as a NREL report.

J. Aho, A. D. Buckspan, F. Dunne, and L. Y. Pao, "Controlling Wind Energy for Utility Grid Reliability," ASME Dynamic Systems and Control Magazine, 1(3): 4-12, Sept. 2013.

J. R. Marden, S. D. Ruben, and L. Y. Pao. "A Model-Free Approach to Wind Farm Control using Game Theoretic Methods," IEEE Trans. Control Systems Technology, 21(4): 1207-1214, July 2013.

E. Simley and L. Y. Pao, "Reducing Lidar Wind Speed Measurement Error with Optimal Filtering," Proc. American Control Conf., Washington, D.C., pp. 621-627, June 2013.

S. Shajiee, L. Y. Pao, P. N. Wagner, E. D. Moore, and R. R. McLeod, "Direct Ice Sensing and Localized Closed-Loop Heating for Active De-icing of Wind Turbine Blades," Proc. American Control Conf., Washington, D.C., pp. 634-639, June 2013.

J. H. Laks, E. J. Simley and L. Y. Pao, "Spectral Models for Evaluating the Effect of Wind Evolution on Wind Turbine Preview Control," Proc. American Control Conf., Washington, D.C., pp. 3679-3685, June 2013.

F. Dunne, and L. Pao, "Benefit of Wind Turbine Preview Control as a Function of Measurement Coherence and Preview Time," Proc. American Control Conf., Washington, D.C., pp. 647-652, June 2013.

A. D. Buckspan, L. Y. Pao, J. P. Aho, and P. Fleming, "Stability Analysis of a Wind Turbine Active Power Control System," Proc. American Control Conf., Washington, D.C., pp. 1420-1425, June 2013.

J. P. Aho, L. Y. Pao, J. Hauser, and A. D. Wright, "Optimal Trajectory Tracking Control for Wind Turbines During Operating Region Transitions," Proc. American Control Conf., Washington, D.C., pp. 1426-1431, June 2013.

E. Simley and L. Y. Pao, "Correlation Between Rotating LIDAR Measurements and Blade Effective Wind Speed," Proc. AIAA Aerospace Sciences Meeting, Grapevine, TX, 15 pages, Jan. 2013.

J. Aho, L. Pao, A. Buckspan, and P. Fleming, "A Novel Active Power Control System for Wind Turbines Capable of AGC and Primary Response," Proc. AIAA Aerospace Sciences Meeting, Grapevine, TX, 13 pages, Jan. 2013.

D. Schlipf, L. Y. Pao, and P. W. Cheng, "Comparison of Feedforward and Model Predictive Control of Wind Turbines Using LIDAR," Proc. IEEE Conf. Decision and Control, Maui, HI, pp. 3050-3055, Dec. 2012.

J. R. Marden, H. P. Young, and L. Y. Pao, "Achieving Pareto Optimality through Distributed Learning," Proc. IEEE Conf. Decision and Control, Maui, HI, pp. 7419-7424, Dec. 2012.

J. Laks, L. Y. Pao, and S. Shajiee, "A Comparison of Multi-Blade Coordinate and Direct Techniques for Asymptotic Rejection of Simultaneous Blade Load and Speed Disturbances in Wind Turbines," Proc. IEEE Conf. Decision and Control, Maui, HI, pp. 2557-2562, Dec. 2012.

A. Buckspan, J. Aho, P. Fleming, Y. Jeong, and L. Pao, "Combining Droop Curve Concepts with Control Systems for Wind Turbine Active Power Control," Proc. IEEE Symp. Power Electronics and Machines in Wind Applications, Denver, CO, 8 pages, July 2012. Also published as a NREL report.

J. Aho, A. Buckspan, J. Laks, P. Fleming, Y. Jeong, F. Dunne, M. Churchfield, L. Pao, and K. Johnson, "A Tutorial of Wind Turbine Control for Supporting Grid Frequency through Active Power Control," Proc. American Control Conf., Montreal, Canada, pp. 3120-3131, June 2012. Also published as a NREL report.

E. Simley, L. Y. Pao, and E. G. Patton, "Simulation of LIDAR Wind Speed Measurements for Wind Turbine Control Applications in an Evolving LES Wind Field," Proc. Int. Symp. Adv. Boundary-Layer Remote Sensing (ISARS), Boulder, CO, 4 pages, June 2012.

E. Simley, L. Y. Pao, N. Kelley, B. Jonkman, and R. Frehlich, "LIDAR Wind Speed Measurements of Evolving Wind Fields," Proc. AIAA Aerospace Sciences Meeting, Nashville, TN, 19 pages, Jan. 2012.

S. Shajiee, P. Wagner, L. Y. Pao, and R. R. McLeod, "Development of Novel Ice Sensing and Active De-icing Method for Wind Turbines," Proc. AIAA Aerospace Sciences Meeting, Nashville, TN, 15 pages, Jan. 2012.

J. R. Marden, S. D. Ruben, and L. Y. Pao, "Surveying Game Theoretic Approaches for Wind Farm Optimization," Proc. AIAA Aerospace Sciences Meeting, Nashville, TN, 10 pages, Jan. 2012.

J. Laks and L. Y. Pao, "LIDAR-Enabled Global Set-point Scheduling for Model Predictive Control of Wind Turbines," Proc. AIAA Aerospace Sciences Meeting, Nashville, TN, 18 pages, Jan. 2012.

F. Dunne, D. Schlipf, L. Y. Pao, A. D. Wright, B. Jonkman, N. Kelley, and E. Simley, "Comparison of Two Independent Lidar-Based Pitch Control Designs," Proc. AIAA Aerospace Sciences Meeting, Nashville, TN, 19 pages, Jan. 2012.

J. Laks, L. Y. Pao, and A. Alleyne, "Comparison of Wind Turbine Operating Transitions using Iterative Learning Control," Proc. American Control Conf., San Francisco, CA, pp. 4312-4319, June 2011.

J. Laks, L. Y. Pao, A. D. Wright, N. Kelley, and B. Jonkman, "The Use of Preview Wind Measurements for Blade Pitch Control," IFAC J. Mechatronics, 21(4): 668-681, June 2011.

F. Dunne, L. Y. Pao, A. D. Wright, B. Jonkman, and N. Kelley, "Adding Feedforward Blade Pitch Control to Standard Feedback Controllers for Load Mitigation in Wind Turbines," IFAC J. Mechatronics, 21(4): 682-690, June 2011.

L. Y. Pao and K. E. Johnson, "Control of Wind Turbines: Approaches, Challenges, and Recent Developments," IEEE Control Systems Magazine, 31(2): 44-62, April 2011.

E. Simley, L. Y. Pao, R. Frehlich, B. Jonkman, and N. Kelley, "Analysis of Wind Speed Measurements Using Continuous Wave LIDAR for Wind Turbine Control," Proc. AIAA Aerospace Sciences Meeting, Orlando, FL, 16 pages, Jan. 2011.

J. Laks, L. Y. Pao, E. Simley, A. D. Wright, N. Kelley, and B. Jonkman, "Model Predictive Control Using Preview Measurements from LIDAR," Proc. AIAA Aerospace Sciences Meeting, Orlando, FL, 20 pages, Jan. 2011.

F. Dunne, L. Y. Pao, A. D. Wright, B. Jonkman, N. Kelley, and E. Simley, "Adding Feedforward Blade Pitch Control for Load Mitigation in Wind Turbines: Non-Causal Series Expansion, Preview Control, and Optimized FIR Filter Methods," Proc. AIAA Aerospace Sciences Meeting, Orlando, FL, 17 pages, Jan. 2011.

J. Laks, L. Y. Pao, A. D. Wright, N. Kelley, and B. Jonkman, "Blade Pitch Control with Preview Wind Measurements," Proc. AIAA Aerospace Sciences Meeting, Orlando, FL, 24 pages, Jan. 2010.

F. Dunne, L. Y. Pao, A. D. Wright, B. Jonkman, and N. Kelley, "Combining Standard Feedback Controllers with Feedforward Blade Pitch Control for Load Mitigation in Wind Turbines," Proc. AIAA Aerospace Sciences Meeting, Orlando, FL, 18 pages, Jan. 2010.

L. Y. Pao and K. E. Johnson, "A Tutorial on the Dynamics and Control of Wind Turbines and Wind Farms," Proc. American Control Conf., St. Louis, MO, pp. 2076-2089, June 2009. ACC09 Presentation File (PDF file)

J. Laks, L. Y. Pao, and A. Wright, "Control of Wind Turbines: Past, Present, and Future," Proc. American Control Conf., St. Louis, MO, pp. 2096-2103, June 2009. ACC09 Presentation File (PPS file (free viewer available here))

J. H. Laks, L. Y. Pao, and A. Wright, "Combined Feedforward/Feedback Control of Wind Turbines to Reduce Blade Flap Bending Moments," Proc. AIAA Aerospace Sciences Meeting, Orlando, FL, 16 pages, Jan. 2009.

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 Systems Magazine, 26(3): 70-81, June 2006.

K. E. Johnson, L. J. Fingersh, L. Y. Pao, and M. J. Balas, "Adaptive Torque Control of Variable Speed Wind Turbines for Increased Region 2 Energy Capture," Proc. ASME Wind Energy Symposium, Reno, NV, Jan. 2005.

K. E. Johnson, L. Y. Pao, M. J. Balas, V. Kulkarni, and L. J. Fingersh, "Stability Analysis of an Adaptive Torque Controller for Variable Speed Wind Turbines," Proc. IEEE Conf. Decision and Control, Paradise Island, Bahamas, pp. 4087-4094, Dec. 2004.

K. E. Johnson, L. Fingersh, M. Balas, and L. Y. Pao, "Methods for Increasing Region 2 Power Capture on a Variable Speed HAWT," ASME J. Solar Energy Engineering, 126(4): 1092-1100, Nov. 2004.

K. E. Johnson, L. J. Fingersh, M. J. Balas, and L. Y. Pao, "Methods for Increasing Region 2 Power Capture on a Variable Speed HAWT," Proc. Wind Energy Symposium, Reno, NV, pp. 103-113, Jan. 2004.