A method (1000-1001) for operating a wind turbine (100) including a rotor (106) having rotor blades (108) and a power conversion system (118, 210, 234) mechanically connected with the rotor (106), configured to convert input motive power into electrical output power, and electrically connected to a network (242) for feeding the electrical output power (P) to the network is provided. The method includes determining (1100) a current frequency (f) of the network (242), and, when the current frequency (f) is equal to or lower than a threshold frequency (f.sub.thresh), operating (1300) the power conversion system (118, 210, 234) at an electrical output power (P) which is increased by an electrical output power increase (PI) in accordance with a monotonic function (PI(f)) of the current frequency (f) limited to a maximum value (PI.sub.max).

A controller structure for a wind turbine having an aerodynamic rotor with at least one rotor blade, wherein the controller structure is designed to control a rotation speed of the rotor of the wind turbine, wherein the controller structure is designed as a cascade control arrangement and has an outer control loop and an inner control loop, wherein the inner control loop receives an input signal which comprises a change in the rotation speed, an acceleration of the rotation speed, a function of the change in the rotation speed and/or a function of the acceleration of the rotation speed.

A method is provided for controlling a wind turbine that has a generator that is controlled via a converter in a boost operation, in which an electrical power that is fed into an electrical transmission network is increased via a generative deceleration of the generator. The method comprises using a control to determining a set point value for a generator torque depending on an actual value of a rotational speed. The determined set point value for the generator torque is applied to a generator via a limiter with a predefinable upper and lower limit. Determining the set point value for the generator torque in boost operation that leads to an increased fed-in electrical power in response to a boost signal; and limiting a temporal change of the set point value for the generator torque in a recovery operation in response to a recovery signal.

A method is provided for operation of a wind turbine having rotor blades attached to a hub, wherein a controller compensates for torsionally induced blade twist. The method includes operating the wind turbine according to a rated power output curve and maximum design thrust value, and periodically or continuously detecting for induced torsional twist in the rotor blades. Upon determination of torsional twist being induced in the rotor blades, the method includes adjusting the maximum thrust value in the control program to compensate for the induced twist. The wind turbine controller then controls pitch of the rotor blades as a function of the increased maximum thrust value so that power output of the wind turbine is not unnecessarily limited or increased by the induced twist on the rotor blades.

A method is provided for controlling a wind turbine that has a generator that is controlled via a converter in a boost operation, in which an electrical power that is fed into an electrical transmission network is increased via a generative deceleration of the generator. The method comprises using a control to determining a set point value for a generator torque depending on an actual value of a rotational speed. The determined set point value for the generator torque is applied to a generator via a limiter with a predefinable upper and lower limit. Determining the set point value for the generator torque in boost operation that leads to an increased fed-in electrical power in response to a boost signal; and limiting a temporal change of the set point value for the generator torque in a recovery operation in response to a recovery signal.

A wind turbine (1) in which the yaw speed of a rotor (4) of the wind turbine (1) is increased, in a direction to reduce yaw error, from a first speed to a faster second speed when at least one of a yaw error threshold and a rate of change in yaw error threshold is exceeded. Yaw error is an amount an axis about which the rotor (4) is rotatable is offset from the wind direction to which the rotor (4) is exposed. As a result, the maximum loads that a wind turbine 1 should withstand may be reduced and lighter wind turbine components result.

Control method for a wind farm connected to a power grid (1) and comprising a plurality of generating units (2). The presence or absence of a voltage disturbance in the grid (1) is determined with the method, and when the presence of a disturbance is determined, the generating units (2) are controlled during said presence so that they generate the required power and the wind farm (100) thereby participates in stabilizing the grid (1). Furthermore, in the method, when the disappearance of said disturbance is determined, the required power continues to be generated with the generating units (2) for a limited time interval in order to provide a smooth and controlled transient until the voltage of the grid (1) stabilizes. Wind farm connected to a grid (1) and comprising a plurality of generating units (2).

A method is provided for operation of a wind turbine having rotor blades attached to a hub, wherein a controller compensates for torsionally induced blade twist. The method includes operating the wind turbine according to a rated power output curve and maximum design thrust value, and periodically or continuously detecting for induced torsional twist in the rotor blades. Upon determination of torsional twist being induced in the rotor blades, the method includes adjusting the maximum thrust value in the control program to compensate for the induced twist. The wind turbine controller then controls pitch of the rotor blades as a function of the increased maximum thrust value so that power output of the wind turbine is not unnecessarily limited or increased by the induced twist on the rotor blades.