Research on vibration suppression effect and energy dissipation mechanism of wind turbine piezoelectric blade

Abstract

The smart wind turbine piezoelectric blade is a conceptual blade proposed for adaptive vibration suppression. However, it is still far from engineering application due to insufficient theoretical and experimental research. Some innovative research has been carried out in this paper in order to provide some basic reference for piezoelectric vibration suppression design for the ultra-long wind turbine blade. First, using a second-developed dynamic model of the wind turbine piezoelectric blade, the evolution patterns of electromechanical–aeroelastic coupling modal and the energy distribution characteristics of wind-induced vibration response were investigated. Then, an aeroelastic model design method of the wind turbine blade that is suitable for the three-dimensional (3D) variable cross-sections was proposed. Afterward, an aeroelastic wind tunnel test of the 15 megawatts (MW) wind turbine piezoelectric blade was conducted. Finally, the wind-induced vibration suppression effect of piezoelectric material was revealed by comparing the time–frequency characteristics and modal energy distribution between the piezoelectric blade and the ordinary blade. The research results demonstrated that the proposed aeroelastic wind tunnel test could accurately reflect the wind-induced vibration characteristics of the piezoelectric blade. The piezoelectric material can narrow the range of sensitive wind angles of the wind turbine blade, increase the critical wind speed for frequency-locked vibration, and prolong the energy accumulation time of aeroelastic instability. Piezoelectric material causes the associated vibration energy to be transferred in the modal space, weakens energy accumulation of the negative damping mode, and strengthens the energy dissipation of the positive damping mode.