Numerical research of an effective measure for stabilising floating wind turbines in shallow water

In order to stabilise floating wind turbines, an innovative motion stabilisation measure is proposed and verified here through conducting a series of numerical researches with the aid of SESAM. In the research, the numerical model of a spar-supported 5 MW floating turbine was developed first to investigate its motion stability in different depths water and under different wave conditions. Then, a new concept of motion stabiliser is proposed, which consists of a number of heave plates that are connected to floating turbine foundation via structural arms. The influences of both the number of heave plates and their arm length on motion reduction are then investigated in order to explore an optimal design of the proposed stabiliser. Considering the dynamic motions of a floating turbine is mainly affected by sea waves, the motion stabilising capability of the proposed stabiliser is investigated over a wide range of wave period 4–36 s. It has been found that after using the proposed motion stabiliser, both the pitch and heave motions of the floating turbine are successfully limited within the most range of wave period, especially when the wave period exceeds 12 s.