The invention relates to a method for operating a wind turbine (10) comprising a rotor (12) and a generator (18), connected to said rotor (12), for outputting electrical power to an electrical grid, said rotor (12) comprising rotor blades (14) whose blade pitch angles () may be moved during operation in order to control the rotational speed (n) of the rotor (12). Upon reaching a rotational speed (n) higher than a rotational speed limit (n.sub.lim) that delimits an operational range (34, 34, 34) of said wind turbine (10), the rotor (12) is forcibly braked by increasing the blade pitch angle () at a predefined positive blade pitch angle movement rate (.sub.r). According to the invention, the rotational speed limit (n.sub.lim) is altered as a function of a blade pitch angle movement rate () set by the control. The invention also relates to a corresponding wind turbine (10).

The present invention relates to methods, controllers, wind turbines and computer program products for controlling a wind turbine. One or more wind speed measurements upstream of a wind turbine are received 202 and a determination of an indication of a current wind speed at the wind turbine is made 204. The indication may include below rated wind speed or above rated wind speed. It is determined 205 if the wind speed is in an up transition region or a down transition region based on the received one or more wind speed measurements and the indication of said current wind speed. If determined that said wind speed is in an up transition region or a down transition region then a boost action is performed 206.

A wind power generating device includes: a power source assembly and a power generating assembly, the power source assembly including a brake disc and a brake actuator, the brake actuator being configured to swing around a lever fulcrum, and the brake actuator being provided with a wind collector on one side with respect to the lever fulcrum to receive wind force and a brake pad corresponding to the brake disc on the other side such that when the wind collector swings backward because of wind force from the front, the brake pad relatively swings frontward to touch the brake disc by leverage so as to apply a brake force to a rotor component of the power source assembly, and the power generating assembly including a maximum power point tracker (MPPT) such that the generated electric energy is stored to an energy storage element under control of the MPPT.

A method for controlling a wind turbine system including an electrical generator, a power converter system, a DC-link, and at least a grid-side breaker arrangement controllable between open and closed states, wherein the method comprises monitoring for the presence of a shutdown event and, in response to identifying the presence of a shutdown event, controlling the wind turbine into a production-ready state, comprising: i) controlling the grid-side breaker arrangement in the closed state; ii) disabling one or more drive signals to the power converter system; and iii) controlling the DC-link of the power converter system in a charged state. Advantageously, this approach reduces the frequency of use of the grid-side breaker arrangement which extends serviceable life considerably, and also allows the wind turbine system to be transitioned rapidly between an operating state and a production-ready state.

A method of activating and/or deactivating a safe mode of operation of a wind turbine is provided, the method including: receiving at least one measurement signal related to a weather condition; filtering of a measuring signal dependent quantity to obtain a filtered signal, wherein the filtered signal depends on whether the measuring signal dependent quantity and/or filtered signal is increasing or decreasing with time; activating and/or deactivating the safe mode of operation based on the filtered signal.

A method for transitioning a wind turbine into an energy harvesting mode in which the wind turbine generates electrical power from wind energy is provided. An energy storage system supplies electrical power to an auxiliary system when the wind turbine is not generating or receiving electrical power sufficient for supplying the auxiliary system. The method includes operating the wind turbine in a first operating mode in which an electrical power supply is ceased; obtaining environmental data including at least one of wind data and meteorological data; and determining if the obtained environmental data meets a predefined condition. If the predefined condition is met, a transition of the operation of the wind turbine into the energy harvesting mode is caused, wherein transitioning the operation into the energy harvesting mode comprises supplying electrical power from the energy storage system to the one or more auxiliary power consumers of the first group.

A method and device for controlling a wind turbine and a storage medium are provided. The method includes obtaining a mapping of the wind turbine; determining a starting power for starting an advance pitch control based on the mapping of the wind turbine; in response to a rotation speed of the wind turbine reaching a first rated rotation speed and a power of the wind turbine reaching the starting power, increasing a motor torque and increasing a pitch angle to make the hub thrust of the turbine change by following the limit boundary of hub thrust; and increasing the pitch angle to maintain the rotation speed of the wind turbine at the first rated rotation speed until a target wind speed is reached, in response to the power of the wind turbine being increased to the exceeded power.

According to an aspect of the invention, a wind farm is provided. The wind farm includes a plurality of wind turbines and a wind farm controller. The controller is configured to detect a high wind condition from at least one wind turbine in the wind farm, reduce a parameter setpoint of at least one other wind turbine, and increase a cut-out wind speed threshold of the at least one other wind turbine.

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.

An APU has a gas turbine engine and a starter generator to be selectively driven by the gas turbine engine. A sensor senses windmilling of components associated with the starter generator. A lock feature limits rotation within the starter generator when windmilling is sensed. A method of operation is also disclosed.