Model scale wave energy converter test device; sonic wave probe array shown in foreground.

Model scale wave energy converter test device; sonic wave probe array shown in foreground.

Existing wave energy converter (WEC) designs produce power efficiently over a narrow band of the full wave frequency spectrum. To achieve commercial viability, WECs must be able to absorb and produce power efficiently across a broad range of frequencies. Sandia is developing and validating control strategies to increase power of WEC devices. To make the difficult leap from theoretical studies to deployable WEC hardware, Sandia is performing research on control algorithm development, numerical simulation, and scaled model testing.

The Advanced WEC Dynamics and Controls project is designed to address six top-level objectives:

1. Use numerical modeling and novel laboratory testing methods to quantitatively compare a variety of control strategies: advanced system identification methods for richer results (better numerical models and better controls)

2. Produce data, analysis and methodology that assist developers in selecting and designing the best control system for their device: provide developers with the information needed to make informed decisions about their specific strategy on PTO control

3. Use numerical modeling and testing to determine the degree to which developed control strategies are device-agnostic: broadly applicable quantitative results, methods and best practices applicable to a wide range of devices

4. Develop strategies to reduce loads, address fatigue, and to handle extreme conditions: reduce loads and high-frequency vibration in both operational and extreme conditions

5. Full wave-to-wire control: absorption, generation, power-electronics and transmission considered in control design

6. Develop novel control strategies and design methodologies:leverage Sandia’s control expertise from aerospace, defense and robotics to develop novel WEC control approaches

Wave tank testing article

Wave tank testing video

A public data set from wave tank testing completed in 2016 is available on MHK-DR.

Sandia & U.S. Navy Team Up on Advanced Wave Energy Testing

G. Bacelli, S. J. Spence, R. G. Coe, A. Mazumdar, D. Patterson, and K. Dullea, “Design and bench testing of a model-scale WEC for advanced PTO control research,” in European Wave and Tidal Energy Conference (EWTEC), Cork, Ireland, 2017.

O. Abdelkhalik, R. G. Coe, G. Bacelli, and D. G. Wilson, “WEC geometry optimization with advanced control,” in International Conference on Ocean, Offshore and Arctic Engineering (OMAE2017), Trondheim, Norway. ASME, 2017.

R.G. Coe, G. Bacelli, O. Abdelkhalik, and D. Wilson, “An assessment of WEC control performance uncertainty,” in International Conference on Ocean, Offshore and Arctic Engineering (OMAE2017). Trondheim, Norway: ASME, 2017.

S. Zou, O. Abdelkhalik, R. Robinett, U. Korde, G. Bacelli, D. Wilson, and R. Coe, “Model predictive control of parametric excited pitch-surge modes in wave energy converters,” International Journal of Marine Energy, vol. 19, pp. 32 – 46, 2017.

G. Bacelli and R. G. Coe, “State estimation for wave energy converters,” Sandia National Laboratories, Tech. Rep. SAND2017-4401, 2017.

G. Bacelli, R. G. Coe, D. Patterson, and D. Wilson, “System identification of a heaving point absorber: Design of experiment and device modeling,” Energies, vol. 10, no. 10, p. 472, 2017.

G. Bacelli and R. G. Coe, “WEC system identification and model validation,” in Marine Energy Technology Symposium (METS2017), Washington, D.C., 2017.

O. Abdelkhalik, S. Zou, R. R. III, G. Bacelli, D. Wilson, R. Coe, and U. A. Korde, “Multi resonant feedback control of three-degree-of-freedom wave energy converters,” IEEE Transactions on Sustainable Energy, vol. PP, no. 99, pp. 1–1, 2017.

O. Abdelkhalik, R. Robinett, S. Zou, G. Bacelli, R. Coe, D. Bull, D. Wilson, and U. Korde, “On the control design of wave energy converters with wave prediction,” Journal of Ocean Engineering and Marine Energy, pp. 1–11, 2016.

R. G. Coe, G. Bacelli, D. Patterson, and D. G. Wilson, “Advanced WEC Dynamics & Controls FY16 testing report,” Sandia National Labs, Albuquerque, NM, Tech. Rep. SAND2016-10094, October 2016.

O. Abdelkhalik, S. Zou, G. Bacelli, R. D. Robinett III, D. G. Wilson, and R. G. Coe, “Estimation of excitation force on wave energy converters using pressure measurements for feedback control,” in OCEANS2016. Monterey, CA: IEEE, 2016.

G. Bacelli, R. G. Coe, D. Wilson, O. Abdelkhalik, U. A. Korde, R. D. Robinett III, and D. L. Bull, “A comparison of WEC control strategies for a linear WEC model,” in Marine Energy Technology Symposium (METS2016), Washington, D.C., April 2016.

D. Wilson, G. Bacelli, R. G. Coe, D. L. Bull, O. Abdelkhalik, U. A. Korde, and R. D. Robinett III, “A comparison of WEC control strategies,” Sandia National Labs, Albuquerque, New Mexico, Tech. Rep. SAND2016-4293, April 2016 2016.

D. Wilson, G. Bacelli, R. G. Coe, R. D. Robinett III, G. Thomas, D. Linehan, D. Newborn, and M. Quintero, “WEC and support bridge control structural dynamic interaction analysis,” in Marine Energy Technology Symposium (METS2016), Washington, D.C., April 2016.

O. Abdelkhalik, S. Zou, R. Robinett, G. Bacelli, and D. Wilson, “Estimation of excitation forces for wave energy converters control using pressure measurements,” International Journal of Control, pp. 1–13, 2016.

S. Zou, O. Abdelkhalik, R. Robinett, G. Bacelli, and D. Wilson, “Optimal control of wave energy converters,” Renewable Energy, 2016.

J. Song, O. Abdelkhalik, R. Robinett, G. Bacelli, D. Wilson, and U. Korde, “Multi-resonant feedback control of heave wave energy converters,” Ocean Engineering, vol. 127, pp. 269–278, 2016.

O. Abdelkhalik, R. Robinett, G. Bacelli, R. Coe, D. Bull, D. Wilson, and U. Korde, “Control optimization of wave energy converters using a shape-based approach,” in ASME Power & Energy, San Diego, CA, 2015.

L. Bull, R. G. Coe, M. Monda, K. Dullea, G. Bacelli, and D. Patterson, “Design of a physical point-absorbing WEC model on which multiple control strategies will be tested at large scale in the MASK basin,” in International Offshore and Polar Engineering Conference (ISOPE2015), Kona, HI, 2015.

R. G. Coe and D. L. Bull, “Sensitivity of a wave energy converter dynamics model to nonlinear hydrostatic models,” in Proceedings of the ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering (OMAE2015). St. John’s, Newfoundland: ASME, 2015.

D. Patterson, D. Bull, G. Bacelli, and R. Coe, “Instrumentation of a WEC device for controls testing,” in Proceedings of the 3rd Marine Energy Technology Symposium (METS2015), Washington DC, Apr. 2015.

R. G. Coe and D. L. Bull, “Nonlinear time-domain performance model for a wave energy converter in three dimensions,” in OCEANS2014. St. John’s, Canada: IEEE, 2014.