Wave Effects on the Performance of Giant Floating Offshore Wind Turbines

Carlos Armenta-Deu; José Lomo

Abstract

The performance of a giant floating offshore wind turbine under the effects of wave misalignment has been modelled and simulated. Heave and period of the sea waves have been considered as the most relevant parameters to determine their effects on the power generation of the floating offshore wind turbine. The simulation has been run for two different situations, a non-restriction tilt angle case and a limited tilt angle case. The limit of the tilt angle has been set up at a value of 15º, since the wind turbine may collapse for higher tilt angles. Power losses have been computed through the variation of the power coefficient, Cp, which has shown a very little impact onto the performance of the FOWT. The results of the simulation show there is a bandwidth with sinusoidal evolution in the power generation with a maximum gap of 3%. Nevertheless, the maximum variation of the power generation, from peak to valley, due to wave effects has been computed as 44.4%. Non-restriction and restriction of the tilt angle cases have shown a similar average power for a day time interval within a 1.6% higher for the tilt restriction case. However, the amplitude of the power generation bandwidth is much higher in the non-restriction tilt case, 5.55 MW, than in the tilt restriction case, 0.80 MW. As a result of this large amplitude if the wind turbine has non-restriction tilt angle it is necessary to modulate the power signal injection into the electric network to avoid instability and fluctuations.

Abstract

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