The invention relates to a method for controlling a wind turbine that comprises a generator, is provided to feed electrical power into an electricity supply grid but has not yet been connected to the electricity supply grid, comprising the steps: generating electrical power using the generator and supplying electrical elements of the wind turbine with the power generated, and to a wind turbine for generating electrical power from the wind and for feeding the electrical power generated into an electricity supply grid, wherein a method according to one of the preceding claims is carried out.

A method for operating a wind turbine, the method including, in response to receiving a request for a system start of the wind turbine, monitoring at least one measured value over a predetermined monitoring period; and effecting the system start in response to determining that the at least one measured value in the monitoring period corresponds to defined specifications, wherein: the at least one measured value is stored continuously in a data storage and a storage period in the data storage corresponds to at least the predetermined monitoring period, and monitoring the at least one measured value in response to receiving the request for the system start comprises checking, on the basis of the data storage, whether the at least one measured value in a storage period corresponding to the monitoring period before the request corresponds to the defined specifications.

The present disclosure is directed to a method for controlling a pitch angle of a rotor blade of a wind turbine. The method includes adjusting, with an actuator, the pitch angle of the rotor blade during a start-up sequence of the wind turbine. The actuator adjusts the pitch angle of the rotor blade by rotating the rotor blade about a pitch axis relative to a hub. The method also includes determining, with a controller, a minimum pitch angle threshold of the rotor blade based on a tip speed ratio of the rotor blade. The method further includes comparing, with the controller, a current pitch angle of the rotor blade to the minimum pitch angle threshold. When the pitch angle meets the minimum pitch angle threshold, the method includes preventing, with the actuator, the pitch angle of the rotor blade from exceeding the minimum pitch angle threshold.

A wind turbine includes a plurality of wind turbine blades; a plurality of hydraulic actuators for controlling respective pitch angles of the wind turbine blades; a first tank storing control oil for the hydraulic actuators; a first hydraulic pump disposed between the plurality of hydraulic actuators and the first tank, for pumping the control oil; a plurality of valves each of which is provided for corresponding one of the hydraulic actuators, for controlling a supply state of the control oil to the hydraulic actuator; and a control part for controlling each of the valves. The control part is configured to, in warm-up of a pitch hydraulic system of the plurality of wind turbine blades, perform an oil transfer operation of changing the pitch angle of the wind turbine blade from a feather side toward a fine side and then returning the pitch angle to the feather side.

A method of controlling a floating-body wind turbine power generating apparatus including a wind turbine generator disposed on a floating body includes a pitch-angle increasing step of increasing a pitch angle of a blade of the wind turbine generator when the wind turbine generator is stopped, so that an aerodynamic braking force is applied to a rotor of the wind turbine generator. In the pitch-angle increasing step, a first change rate of the pitch angle of the blade in a first period during which the wind turbine generator is in an inclining motion toward an upwind side from a vertical direction due to sway of the floating body, is smaller than a second change rate of the pitch angle of the blade in a second period during which the wind turbine generator is in an inclining motion toward a downwind side from the vertical direction due to the sway of the floating body.

Methods of operating a wind turbine including one or more geared pitch systems. The method comprises a sub-nominal zone of operation for wind speeds below nominal and a supra-nominal zone of operation for wind speeds equal to or above the nominal. The sub-nominal zone of operation comprises a first operational range extending from a cut-in wind speed to a first wind speed and a second operational range extending from the first wind speed to a second wind speed, and the first operational range comprises two or more sub-ranges, wherein a different constant pitch position is defined for each of the sub-ranges. The method further comprises in the first operational range, using the geared pitch systems for setting the blades in the pitch position defined for each sub-range as a function of the current wind speed.

A blade adjusting device for a wind turbine is connected to a plant safety chain and can open and close the plant safety chain by activating a switch. If a fault is detected in one of the blade adjusting devices, the respective control unit can open the plant safety chain. By opening the safety chain, a signal is sent to the blade adjusting devices, and so all the blade adjusting devices initiate a synchronous safety operation of at least two rotor blades when the signal is received.

A method including operating the wind turbine in a first operating mode which an auxiliary system of the wind turbine is supplied with electrical power from an energy storage system of the wind turbine, wherein in the first operating mode, a first group auxiliary power consumers of the auxiliary system and a second group auxiliary power consumers of the auxiliary system are supplied with electrical power from the energy storage system. Upon fulfillment of a predefined condition, the wind turbine is operated in a second operating mode wherein the power supply from the energy storage system to the first group of auxiliary power consumers is ceased. Upon a charging state of the energy storage system reaching or dropping below a predetermined charging level, the wind turbine may be operated in a third operating mode in which auxiliary power supply is ceased.

The present subject matter is directed to a system and method for operating a wind turbine. More specifically, the system and method determines a dynamic cut-in wind speed for the wind turbine based on one or more environmental conditions. In one embodiment, the method includes providing a predetermined cut-in wind speed for the wind turbine based on at least one estimated environmental condition for a wind turbine site; determining one or more actual environmental conditions near the wind turbine for a predetermined time period at the wind turbine site; determining a variance between the at least one estimated environmental condition and the one or more actual environmental conditions; calculating a dynamic cut-in wind speed based on the variance; and, operating the wind turbine based on the dynamic cut-in wind speed so as to increase wind turbine operational efficiency.

A method for operating a wind turbine comprising an aerodynamic rotor with an approximately horizontal axis of rotation, an electrical generator and operating devices is disclosed, wherein the wind turbine is intended for feeding electrical energy into an electrical supply grid, and is kept in a starting state for starting the generator while the wind turbine cannot be completely put into operation, in particular the generator cannot be started.