Evaluation of the Double Snap-Through Mechanism on the Wave Energy Converter’s Performance

Abstract

Lower efficiencies induce higher energy costs and pose a barrier to wave energy devices’ commercial applications. Therefore, the efficiency enhancement of wave energy converters has received much attention in recent decades. The reported research presents the double snap-through mechanism applied to a hemispheric point absorber type wave energy converter (WEC) to improve the energy absorption performance. The double snap-through mechanism comprises four oblique springs mounted in an X-configuration. This provides the WEC with different dynamic stability behaviors depending on the particular geometric and physical parameters employed. The efficiency of these different WEC behaviors (linear, bistable, and tristable) was initially evaluated under the action of regular waves. The results for bistable or tristable responses indicated significant improvements in the WEC’s energy capture efficiency. Furthermore, the WEC frequency bandwidth was shown to be significantly enlarged when the tristable mode was in operation. However, the corresponding tristable trajectory showed intra-well behavior in the middle potential well, which induced a more severe low-energy absorption when a small wave amplitude acted on the WEC compared to when the bistable WEC was employed. Nevertheless, positive effects were observed when appropriate initial conditions were imposed. The results also showed that for bistable or tristable responses, a suitable spring stiffness may cause the buoy to oscillate in high energy modes.

Keywords

Wave energy converter / Point absorber / Double snap-through mechanism / Bistable dynamic behavior / Tristable dynamic behavior

References

[1] Al Shami E, Zhang R, Wang X. Point absorber wave energy harvesters: a review of recent developments. Energies, 2019, 12(1): 47

[2] Andersen P, Pedersen TS, Nielsen KM, Vidal E, (2015). Model predictive control of a wave energy converter. 2015 IEEE Conf. Control Appl. CCA 2015 - Proc, Sydney, 1540–1545. https://doi.org/10.1109/CCA.2015.7320829

[3] Anvari-Moghaddam A, Mohammadi-Ivatloo B, Asadi S, Larsen KG, Shahidehpour M (2020) Sustainable energy systems planning, integration, and management. Applied Sciences, Switzerland. MDPI. https://doi.org/10.3390/app9204451

[4] Astariz S, Iglesias G. The economics of wave energy: a review. Renew Sust Energ Rev, 2015, 45: 397-408

[5] Babarit A, Clément AH. Optimal latching control of a wave energy device in regular and irregular waves. Appl Ocean Res, 2006, 28(2): 77-91

[6] Budal K, Falnes J. Wave power conversion by point absorbers: a Norwegian project. Int J Ambient Energy, 1982, 3: 59-67

[7] Cummins WE (1962) The impulse response function and ship motions. Navy Dep, David Taylor Model Basin

[8] Czech B, Bauer P. Wave energy converter concepts: design challenges and classification. IEEE Ind Electron Mag, 2012, 6: 4-16

[9] Daqaq MF, Masana R, Erturk A, Quinn DD. On the role of nonlinearities in vibratory energy harvesting: a critical review and discussion. Appl Mech Rev, 2014, 66(4): 040801

[10] Edenhofer O, Madruga RP, Sokona Y, Seyboth K, Matschoss P, Kadner S, Zwickel T, Eickemeier P, Hansen G, Schlömer S, von Stechow C. Renewable energy sources and climate change mitigation: special report of the intergovernmental panel on climate change, 2011, Cambridge, United Kingdom: Cambridge University Press

[11] Enerdata (2021) EnerOutlook 2050. Available from https://eneroutlook.enerdata.net/. Accessed 4 Mar 2021

[12] Faedo N, Olaya S, Ringwood JV. Optimal control, MPC and MPC-like algorithms for wave energy systems: an overview. IFAC J Syst Control, 2017, 1: 37-56

[13] Falcão AFDO. Phase control through load control of oscillating-body wave energy converters with hydraulic PTO system. Ocean Eng, 2008, 35(3-4): 358-366

[14] Falcão AFDO. Wave energy utilization: a review of the technologies. Renew Sust Energ Rev, 2010, 14(3): 899-918

[15] Falnes J. Ocean waves and oscillating systems: linear interactions including wave-energy extraction, 2002, Cambridge: Cambridge University Press

[16] Garcia-Rosa PB, Kulia G, Ringwood JV, Molinas M. Real-time passive control of wave energy converters using the Hilbert-Huang transform. IFAC-PapersOnLine, 2017, 50(1): 14705-14710

[17] Goggins J, Finnegan W. Shape optimisation of floating wave energy converters for a specified wave energy spectrum. Renew Energy, 2014, 71: 208-220

[18] Harne RLKWW (2017) Harnessing bistable structural dynamics: for vibration control, energy harvesting and sensing. Wiley

[19] Henriques JCC, Gato LMC, Falcão AFO, Robles E, Faÿ FX. Latching control of a floating oscillating-water-column wave energy converter. Renew Energy, 2016, 90: 229-241

[20] Hulme A. The wave forces acting on a floating hemisphere undergoing forced periodic oscillations. J Fluid Mech, 1982, 121: 443-463

[21] Jin S, Patton RJ, Guo B. Enhancement of wave energy absorption efficiency via geometry and power take-off damping tuning. Energy, 2019, 169: 819-832

[22] Li G, Belmont MR. Model predictive control of sea wave energy converters - Part I: A convex approach for the case of a single device. Renew Energy, 2014, 69: 453-463

[23] Li G, Belmont MR. Model predictive control of sea wave energy converters - Part II: The case of an array of devices. Renew Energy, 2014, 68: 540-549

[24] Li L, Zhang X, Yuan Z, Gao Y. Multi-stable mechanism of an oscillating-body wave energy converter. IEEE Trans Sustain Energy, 2019, 11(1): 500-508

[25] Maria-Arenas A, Garrido AJ, Rusu E, Garrido I (2019) Control strategies applied to wave energy converters: State of the art. Energies 12(16). https://doi.org/10.3390/en12163115

[26] Ogilvie TF (1964) Recent progress toward the understanding and prediction of ship motions. Proceedings of the 5th Symposium on Naval Hydrodynamics, Bergen, Norway

[27] Pérez T, Fossen TI. Time-vs. frequency-domain identification of parametric radiation force models for marine structures at zero speed. Model. Identif. Control, 2008, 29(1): 1-19

[28] Pérez T, Fossen TI. A Matlab toolbox for parametric identification of radiation-force models of ships and offshore structures. Model Identif Control, 2009, 30(1): 1-15

[29] Ramlan R, Brennan MJ, MacE BR, Kovacic I. Potential benefits of a non-linear stiffness in an energy harvesting device. Nonlinear Dyn, 2010, 59: 545-558

[30] Reguero BG, Losada IJ, Méndez FJ. A recent increase in global wave power as a consequence of oceanic warming. Nat Commun, 2019, 10: 1-14

[31] Rodríguez CA, Rosa-Santos P, Taveira-Pinto F. Assessment of damping coefficients of power take-off systems of wave energy converters: a hybrid approach. Energy, 2019, 169: 1022-1038

[32] Shadman M, Estefen SF, Rodriguez CA, Nogueira ICM. A geometrical optimization method applied to a heaving point absorber wave energy converter. Renew Energy, 2018, 115: 533-546

[33] Shadman M, Silva C, Faller D, Wu Z, de Freitas Assad LP, Landau L, Levi C, Estefen SF. Ocean renewable energy potential, technology, and deployments: a case study of Brazil. Energies, 2019, 12(19): 3658

[34] Todalshaug JH (2015) Wave energy converter. International Patent WO 2015/107158 Al

[35] Todalshaug JH, Ásgeirsson GS, Hjálmarsson E, Maillet J, Möller P, Pires P, Guérinel M, Lopes M. Tank testing of an inherently phase-controlled wave energy converter. Int J Mar Energy, 2016, 15: 68-84

[36] Wei C, Jing X. A comprehensive review on vibration energy harvesting: modelling and realization. Renew Sust Energ Rev, 2017, 74: 1-18

[37] Wu Z, Levi C, Estefen SF. Wave energy harvesting using nonlinear stiffness system. Appl Ocean Res, 2018, 74: 102-116

[38] Wu Z, Levi C, Estefen SF. Practical considerations on nonlinear stiffness system for wave energy converter. Appl Ocean Res, 2019, 92: 101935

[39] Younesian D, Alam MR. Multi-stable mechanisms for high-efficiency and broadband ocean wave energy harvesting. Appl Energy, 2017, 197: 292-302

[40] Zhang X, Yang J. Power capture performance of an oscillating-body WEC with nonlinear snap through PTO systems in irregular waves. Appl Ocean Res, 2015, 52: 261-273

[41] Zhang X, Yang J, Xiao L. Numerical study of an oscillating wave energy converter with nonlinear snap-through Power-Take-Off systems in regular waves. J Ocean Wind Energy, 2014, 1: 225-230

[42] Zhang X, Tian X, Xiao L, Li X, Chen L. Application of an adaptive bistable power capture mechanism to a point absorber wave energy converter. Appl Energy, 2018, 228: 450-467

[43] Zhang X, Tian X, Xiao L, Li X, Lu W (2019a) Mechanism and sensitivity for broadband energy harvesting of an adaptive bistable point absorber wave energy converter. Energy 188:115984. https://doi.org/10.1016/j.energy.2019.115984

[44] Zhang H, Xi R, Xu D, Wang K, Shi Q, Zhao H, Wu B (2019b) Efficiency enhancement of a point wave energy converter with a magnetic bistable mechanism. Energy 181:1152–1165. https://doi.org/10.1016/j.energy.2019.06.008