The present invention relates to a wind turbine comprising an internal power supply grid for distributing power to a number of power consuming units of the wind turbine, the wind turbine further comprising a power backup system connected to the internal power supply grid for supplying power to said internal power supply grid during a grid fault, wherein the power backup system comprises a controllable power storage module providing a total backup voltage that falls within a nominal voltage range of the internal power supply grid of the wind turbine. The present invention also relates to a power backup system and an associated method.

A method of operating a wind energy installation wherein a rotor has a first rotor blade which can be angularly adjusted, a first adjustment drive for adjusting the rotor blade, and a safety control system. In a normal mode of operation, the first adjustment drive is supplied with energy from a source and is controlled by a first pitch control system. In a failure mode of operation, the supply of energy to the first adjustment drive is switched from the source to an energy storage device and the safety control system monitors a position and/or movement of the first rotor blade. The first rotor blade is adjusted by the first adjustment drive in a direction of a predetermined stopping position, while the safety control system, as a function of the monitored position and/or movement, enables or effects a deactivation of a first power supply shut-off device. In the failure mode of operation, the safety control system, as a function of the monitored position and/or movement, closes a first pitch brake and activates a first blocking mode in which the supply of energy to the first adjustment drive from the energy storage device and/or an opening of the first pitch brake is prevented.

A wind turbine with at least one rotor blade and at least one pith drive for turning the at least one rotor blade, the wind turbine comprising a controller which analyses the wind turbine if a first error situation or a second error situation occurs and wherein the controller is adapted to react to the first error situation in absence of a second error situation with a first error procedure, to a second error situation in absence of the first error situation with a second error procedure, and to an error situation where the first error and the second error occur at the same time with a third error procedure that is different to the first error procedure and to the second error procedure.

A method for controlling the pitch angle of the blades including the following steps of: measuring an energy storage of the blades pitch actuation system at predefined values of a first blade pitch angle interval; comparing the measured values of the energy storage of the blades pitch actuation system with a predefined minimum value of the energy storage; if the measured values of the energy storage are all greater or equal than the predefined minimum value of the energy storage then enabling normal operation; if at least one of the measured values of the energy storage are lower than the predefined minimum value then: calculating a third pitch angle calculating a third blade pitch angle interval extending between a fourth pitch angle and the second pitch angle; and limiting the blades pitch actuation system to operate only in the third pitch angle interval.

A method for controlling the pitch angle of the blades including the following steps of: measuring an energy storage of the blades pitch actuation system at predefined values of a first blade pitch angle interval; comparing the measured values of the energy storage of the blades pitch actuation system with a predefined minimum value of the energy storage; if the measured values of the energy storage are all greater or equal than the predefined minimum value of the energy storage then enabling normal operation; if at least one of the measured values of the energy storage are lower than the predefined minimum value then: calculating a third pitch angle at which the energy storage equals the predefined minimum value calculating a third blade pitch angle interval extending between a fourth pitch angle and the second pitch angle and limiting the blades pitch actuation system to operate only in the third pitch angle interval.

A method for testing capacity of at least one energy storage device of a pitch drive mechanism to drive a first rotor blade of a wind turbine connected to a power grid includes defining a rotor position range for implementing a first test procedure for the energy storage device(s). Further, the method includes monitoring a rotor position of the first rotor blade. When the rotor position of the first rotor blade enters the rotor position range, the method includes initiating the first test procedure. The first test procedure includes pitching the first rotor blade via the energy storage device(s), measuring at least one operating condition of the energy storage device(s) during pitching, and determining a capacity of the energy storage device(s) to drive the first rotor blade based on the operating condition(s) thereof.

A method of diagnosing a wind turbine power generating apparatus includes: an operation step of operating a pitch actuator corresponding to one of a plurality of wind turbine blades of the wind turbine power generating apparatus, without operating a pitch actuator corresponding to each of the wind turbine blades other than the one of the plurality of wind turbine blades; and a measurement step of measuring a response value indicating a response to operation of the pitch actuator corresponding to the one of the plurality of wind turbine blades. The operation step and the measurement step are performed repeatedly for each of the plurality of wind turbine blades, and the response value is obtained as data for health check of a blade pitch mechanism of the wind turbine power generating apparatus.

A fan failure backup apparatus includes a first fan module and a second fan module. When a second control unit of the second fan module realizes that the first fan module is failed through a first control unit of the first fan module, and the second control unit realizes that the second fan module is not failed, the second control unit controls the second fan module to additionally enhance a pressure-flow characteristic of a second fan unit of the second fan module.

A system and method for protecting an idling wind turbine power system from damage during loss of grid power. The wind turbine power system has a plurality of rotor blades. The method includes monitoring an incoming wind direction at the wind turbine power system. When the incoming wind direction is changing at a predetermined attack angle, the method also includes rotating at least one of the rotor blades of the wind turbine power system to a pitch angle that is offset from a feather position by a predetermined number of degrees to reduce and/or eliminate flutter phenomenon from occurring.

A method for estimating consumed battery life of at least one battery of a pitch drive mechanism of a rotor blade of a wind turbine includes monitoring, via at least one sensor, an actual temperature of the battery over a predetermined time period. The method also includes storing, via a turbine controller, the monitored actual temperatures of the battery during the predetermined time period. Further, the method includes determining, via the turbine controller, the consumed battery life as a function of the monitored actual temperatures.