Reduction of wave-induced pitch motion of a semi-sub wind platform by balancing heave excitation with pumping between floats
Tóm tắt
It is desirable to control pitch motion of semi-submersible wind platforms to reduce turbine hub acceleration and increase structural fatigue life. This is achieved by balancing the moment on the platform due to heave float excitation by generating a differential internal head of water between the floats though a pump. This is demonstrated with an experimentally validated linear diffraction-radiation-drag model of an idealised platform. Different scales of platform are considered corresponding to 5, 10 and 20 MW turbines. The pitch angles and hub accelerations generally reduce as scales increase. Pumping reduces hub accelerations by up to about 40% for larger sea states. The power required for pumping would be small with a hybrid pump also operating as a turbine to store energy for the pumping operation. Without storage the power requirement is still small relative to the turbine capacity except for very high wind speeds.
Tài liệu tham khảo
Apsley DD, Stansby PK (2020) Unsteady thrust on an oscillating wind turbine: comparison of blade-element momentum theory with actuator-line CFD. J Fluids Struct 98:103141
Cummins WE (1962) The impulse response function and ship motions. Schiffstechnik 9:101–109
DNVGL (2019) DNVGL-RP-0286 Coupled analysis of floating wind turbines
Fath A, Yazdi EA, Eghtesad M (2020) Semi-active vibration control of a semi-submersible offshore wind turbine using a tuned liquid multi-column damper. J Ocean Eng Mar Energy 6:243–262
Graham JMR (1980) The forces on sharp-edged cylinders in oscillatory flow at low Keulegan–Carpenter numbers. J Fluid Mech 97:331–346
Gu H, Stansby P, Stallard T, Carpintero Moreno E (2018) Drag, added mass and radiation damping of oscillating vertical cylindrical bodies in heave and surge in still water. J Fluids Struct 82(343–356):20
Hsu SA, Meindl EA, Gilhousen DB (1994) Determining the power-law wind-profile exponent under near-neutral stability conditions at sea. J Appl Meteor 33:757–765
Jonkman J, Butterfield S, Musial W, Scott G (2009) Definition of a 5-MW reference wind turbine for offshore system development, Technical Report NREL/TP-500-38060
Lee CH, Newman JN (2013) WAMIT—User manual version 7.0. WAMIT Inc, Chestnut Hill, Massachusetts
Liao Z, Stansby P, Li G (2020) A generic linear non-causal optimal control framework integrated with wave excitation force prediction for multi-mode wave energy converters with application to M4. Appl Ocean Res 97:102056
Mazouk OA, Nayfeh AH (2009) Control of ship roll using passive and active anti-roll tanks. Ocean Eng 36:661–671
Mei CC (1999) The applied dynamics of ocean surface waves. World Scientific, Singapore
Moaleji R, Greig AR (2007) On the development of ship anti-roll tanks. Ocean Eng 34:103–121
Robertson A, Jonkman J , Masciola M, Song H, Goupee A, Coulling A, Luan C (2014) Definition of the semisubmersible floating system for Phase II of OC4, NREL Technical Report NREL/TP-5000-60601
Roddier D, Cermelli C (2015) Floating wind turbine platform with ballast control and mooring system, US patent no. US 9,139,266 B2
Roddier D, Cermelli C, Aubault A, Weinstein A (2010) Windfloat: a floating foundation for offshore wind turbines. J Renew Sustain Energy 2:033104
Shore Protection Manual (1973) US Army Corps Engineers, Coastal Engineering Research Center. US Gov. Printing Office, Washington DC
Stansby P, Carpintero Moreno E (2020) Study of snap loads for idealized mooring configurations with a buoy, inextensible and elastic cable combinations for the multi-float M4 wave energy converter, Water, 12, 2818, Special issue on Numerical and Experimental Modelling of Wave Field Variations around Arrays of Wave Energy Converters
Stansby PK, Carpintero Moreno E, Apsley DD, Stallard TJ (2019) Slack-moored semi-submersible wind floater with damping plates in waves: linear diffraction modelling with mean forces and experiments. J Fluids Struct 90:410–431
Tao L, Thiagarajan K (2003) Low KC flow regimes of oscillating sharp edges. II. hydrodynamic forces. Appl Ocean Res 25:53–62
Zhang Y, Stansby P, Li G (2020) Non-causal linear optimal control with adaptive sliding mode observer for multi-body wave energy converters. IEEE Trans Sustain Energy. https://doi.org/10.1109/TSTE.2020.3012412