Izaskun Garrido, Aitor Garrido, Iñigo J. Oleagordia, Jon Lecube, Manuel De la Sen



Control Models for an Oscillating Water Column Device

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The primary focus of this manuscript is to advance wave energy converter (WEC) devices. Having this aim in mind, a power take off (PTO) system with novel rotational speed control strategies will be presented. The chosen take off system is an oscillating water column converter (OWC), a device that uses a Wells air turbine as the primary energy converter. The secondary of the device is a generator that has been chosen to be a Doubly Fed Induction Generator with novel control strategies. This set up aims to improve the performance by increasing the efficiency, as a result of an increment in the power captured, and providing quality power to the grid. The proposed control scheme is due to be implemented on the NEREIDA MOWC demonstration project, a breakwater wave plant located in the Basque location of Mutriku, using Wells turbines and induction generators. The difficulty lies in finding an efficient variable control speed operation able to smoothly convert the peak-to-average power ratio, even more when this ratio presents a broad bandwidth that relates to the diverse input wave periods. By controlling the slip of the generator, it is possible to determine the behaviour of the whole turbo-generator set so as to maximize the output power. At the same time, the Wells turbine contributes to the robustness of the system because it requires no additional parts to produce unidirectional rotation from the reversing oscillating flow, but its performance is hindered by the stalling behaviour. However, this stalling phenomenon is s non-uniform response that may be avoided by controlling the rotational speed. Therefore, the presented novel control and switching avoidance techniques, will greatly contribute towards an improved PTO for the wave energy sector.


Speed Control, Wave Energy, OWC, DFIG


[1] Y. Torre-Enciso, I. Ortubia, L. I. López de Aguileta, J. Marqués, “Mutriku wave power plant: From the thinking out the reality”, in Proc. 8th Eur. Wave Tidal Energy Conf., 2009, pp. 319-329.

[2] Garrido, A.J., Garrido, I., Alberdi, M., Amundarain, M., Barambones, O., Romero, J.A. “Robust control of oscillating water column (OWC) devices: Power generation improvement”. OCEANS 2013 MTS/IEEE - San Diego: An Ocean in Common, art. no. 6740982. 2013.

[3] A Amundarain, M., Alberdi, M., Garrido, A.J., Garrido, I. Neural rotational speed control for wave energy converters (2011) International Journal of Control, 84 (2), pp. 293-309. DOI: 10.1080/00207179.2010.55114.

[4] Garrido, A.J., Garrido, I., Otaola, E., Lekube, J., M'Zoughi, F., Ghefiri, K., Mundackamattam, D.G., Oleagordia, I. Capture chamber modelling and validation in OWC on-shore devices (2017) IEEE TENCON, art. no. 7848304, DOI: 10.1109/TENCON.2016.7848304.

[5] Amundarain Ormaza, M., Alberdi Goitia, M., Garrido Hernández, A.J., Garrido Hernández, I. “Neural control of the Wells turbine-generator module” 2009 IEEE Conference on Decision and Control, art. no. 5400638, pp. 7315-7320, 2009. DOI: 10.1109/CDC.2009.5400638.

[6] M De la Sen, V Hedayati, YG Atani, S Rezapour. "The existence and numerical solution for a k-dimensional system of multi-term fractional integro-differential equations", Nonlinear Analysis, Modelling and Control 22 (2), 188-209.

[7] Rusu, E., 2014. Evaluation of the Wave Energy Conversion Eiciency in Various Coastal Environments, Energies 2014, Special Issue Selected Papers from the 1st International e-Conference on Energies, 7(6) 4002-4018.

[8] Garrido, A.J., Garrido, I., Lekube, J., De La Sen, M., Carrascal, E. Modeling of Oscillating Water Column wave energy systems (2016) World Automation Congress Proceedings, 2016-October, art. no. 7583008, .DOI: 10.1109/WAC.2016.7583008.

[9] Garrido, A.J., De La Sen, M., Soto, J.C., Barambones, O., Garrido, I. “Suboptimal regulation of a class of bilinear interconnected systems with finite-time sliding planning horizons” in Mathematical Problems in Engineering, art. no. 817063, 2008. DOI: 10.1155/2008/817063.

[10] A Czornik, A Konyukh, M Niezabitowski. “Which functions may be the upper Bohl function of the diagonal discrete linear time-varying systems?” Journal of Mathematical Analysis and Applications 452 (2), 1420-1433

[11] M De la Sen. "On fixed and best proximity points of cyclic C-contractions in probabilistic complete metric and Banach spaces", Bulletin of the Malaysian Mathematical Sciences Society 40 (3), 1321-1340

[12] A Babiarz, M Niezabitowski. "Controllability Problem of Fractional Neutral Systems: A Survey". Mathematical Problems in Engineering, DOI: 10.1155/2017/4715861.

[13] M Niezabitowski. “On the Sequences Realizing Perron and Lyapunov Exponents of Discrete Linear Time-Varying Systems” Mathematical Problems in Eng. DOI: 10.1155/2016/1487824.

[14] Silva, D.,Rusu, E, Guedes Soares, C, 2013, Evaluation of VariousTechnologies for Wave Energy Conversion in the Portuguese Nearshore, Energies, 6(3), 1344-1364.

[15] Sevillano, G., Garrido, I., Garrido, A.J. ASTRA-matlab integration for the control of tokamaks (2011) Informatica, 22 (2), pp. 241-257.

[16] Garrido, I., Romero, J.A., Garrido, A.J., Lucchin, D., Carrascal, E., Sevillano-Berasategui, G. “Internal inductance predictive control for Tokamaks” (2014) World Automation Congress Proceedings, art. no. 6936072, pp. 628-633. DOI: 10.1109/WAC.2014.6936072.

[17] Rusu, E., Onea, F, 2016, Estimation of the wave energy conversion efficiency in the Atlantic Ocean close to the European islands, Renewable Energy 85, 687-703.

[18] Garrido, I., Garrido, A.J., Lekube, J., Otaola, E., Carrascal, E. Oscillating water column control and monitoring (2016) OCEANS 2016 MTS/IEEE Monterey, OCE 2016, art. no. 7761420, .DOI: 10.1109/OCEANS.2016.7761420 .

[19] ME Gordji, M Ramezani, M De La Sen, YJ Cho. "On orthogonal sets and Banach fixed point theorem", Fixed Point Theory, DOI: 10.24193/fpt-ro.2017.2.45.

[20] Artur Babiarz, Jerzy Klamka, Radosław Zawiski, Michał Niezabitowski, “An Approach to Observability Analysis and Estimation of Human Arm Model”, Proceedings of the 11th IEEE International Conference on Control & Automation, Taichung, Taiwan, pp. 947-952 (2014).

[21] A Babiarz, A Czornik, E Makarov, M Niezabitowski, S Popova. "Pole Placement Theorem for Discrete Time-Varying Linear Systems", SIAM J. on Control and Optimization 55 (2), 671-692.

[22] De la Sen, Manuel. “On Weak Contractive Cyclic Maps in Generalized Metric Spaces and Some Related Results on Best Proximity Points and Fixed Points”, Discrete Dynamics in Nature and Society. 2016. 1-14. 10.1155/2016/4186960.

[23] Aitor J. Garrido, Izaskun Garrido, Odysseas Chalatsakos, Ander Viñas, Ainhoa Villaverde, Vicente Queral and Jesús A. Romero, “Modelling and control of the UPV/EHU Stellarator”, IEEE 23rd MED, (2015). DOI: 10.1109/MED.2015.7158785.

[24] Rusu, L., Onea, F, 2015, Assessment of the performances of various wave energy converters along the European continental coasts, Energy, 82, 889–904.

[25] Nistal, R., De La Sen, M., Alonso-Quesada, S., Ibeas, A., Garrido, A.J., “On the stability and equilibrium points of multistaged SI (n) R epidemic models” (2015), Discrete Dynamics in Nature and Society, 2015, art. no. 379576. DOI: 10.1155/2015/379576.

[26] Sevillano, M.G., Garrido, I., Garrido, A.J., “Control-oriented Automatic System for Transport Analysis (ASTRA)-Matlab integration for Tokamaks” (2011) Energy, 36 (5), pp. 2812-2819. DOI: 10.1016/j.energy.2011.02.022.

[27] A Babiarz, A Czornik, M Niezabitowski et. al. "relations between bohl and general exponents", discrete and continuous dynamical systems 37 (10), 5319-5335

[28] Emulation of an OWC Ocean Energy Plant With PMSG and Irregular Wave Model: IEEE Transactions on Sustainable Energy Vol. :6, Issue: 4, Oct. 2015 DOI: 10.1109/TSTE.2015.2455333.

[29] Ormaza, M.A., Goitia, M.A., Hernandez, I. Garrido, A.J. Garrido Wells turbine control in wave power generation plants IEMDC '09, art. no. 5075202, DOI: 10.1109/IEMDC.2009.5075202.

[30] Lekube, J., Garrido, A.J., Garrido, I. Rotational Speed Optimization in Oscillating Water Column Wave Power Plants Based on Maximum Power Point Tracking (2016) IEEE Transactions on Automation Science and Engineering, .DOI: 10.1109/TASE.2016.2596579.

[31] Garrido, A.J., Otaola, E., Garrido, I., Lekube, J., Liria, P., Mader, J. OWC wave power plants capture chamber modeling (2016) OCEANS 2015 - MTS/IEEE Washington, art. no. 7401863.

[32] Garrido, A.J., Otaola, E., Garrido, I., Lekube, J., Liria, P., Mader, J. OWC wave power plants capture chamber modeling (2016) OCEANS 2015 - MTS/IEEE Washington, art. no. 74018631.

[33] Garrido, A.J., Otaola, E., Garrido, I., Lekube, J., Maseda, F.J., Liria, P., Mader, J..Mathematical Modeling of Oscillating Water Columns Wave-Structure Interaction in Ocean Energy Plants (2015) Mathematical Problems in Engineering, 2015, art. no. 727982, .DOI: 10.1155/2015/727982.

Cite this paper

Izaskun Garrido, Aitor Garrido, Iñigo J. Oleagordia, Jon Lecube, Manuel De la Sen. (2017) Control Models for an Oscillating Water Column Device. International Journal of Renewable Energy Sources, 2, 109-114


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