Wind turbine idling and power generation

Do wind turbine rotors stall at idling state?

Although many investigations on the structural dynamics and stabilities of the wind turbine rotors have been conducted, the results on the stall-induced vibration analysis and mitigation of the wind turbine rotors at idling state by means of the theoretical and experimental methods are very few.

How can wind turbine loads be predicted?

Present design practices and recognized standards for wind turbine loads and safety, e.g., IEC 61400-1,5 require ultimate loads from the fluctuating wind to be predicted using both discrete gust models and advanced simulations of the 3-D stochastic turbulent wind field as input to comprehensive aero-elastic models.

Does a wind turbine rotor have stall-induced vibrations?

This paper investigates the stall-induced vibrations of a wind turbine rotor operating at idling state, and a strategy to mitigate the stall-induced vibrations is proposed. The equations of motion of the wind turbine rotor are established by Hamilton's principle and solved using the finite element method (FEM).

Does a horizontal axis wind turbine idle or parked?

The aeroelastic responses of the wind turbines at idling or parked state were also investigated. Chen et al. adopted an improved theory to determine the aero-damping for a horizontal axis wind turbine. The blade flexibility, shaft tilt and yawing angle, as critical design variables, were analyzed in the aero-damping estimation.

Why are wind turbine rotors so difficult to design?

With the development of wind turbine manufacturing technology, the wind turbine rotor is facing more design challenges for exposing to complex environmental conditions and severe wind loads.

What determines stall induced vibration in a wind turbine?

The aerodynamic forces are determined by the blade element theory, and the aero-damping ratio is defined by the eigenvalue of the rotor system. Stability analysis shows that the stall-induced vibration occurs when a wind turbine stands still at high wind speeds with specific wind deviation angles.