The invention relates to a method of reducing oscillations in an offshore wind turbine comprising one or more thrusters, the method comprising determining an oscillation of the offshore wind turbine and operating the one or more thrusters such that the oscillation is reduced. The invention further relates to an offshore wind turbine comprising one or more underwater thrusters, oscillation determination system for determining an oscillation of the wind turbine and a control system for operating the underwater thrusters in response to signals received from the oscillation determination system.

A method of controlling a wind turbine comprising blades attached to a rotor hub for rotation in a rotor plane and a control system for individually pitching the blades relative to the hub. The method comprises dividing the rotor plane into a number of sectors, determining the individual sectors for each blade during the rotation by means of an azimuth angle sensor, and obtaining blade sensor data from a blade sensor on an individual blade relating to a sector, and comparing the obtained data with data relating to the same sector and representing blade sensor data on other blades. When an event is detected in a given sector, an individual pitch contribution is determined in the sector, and the blades are then pitched according to this individual pitch contribution for that given sector at least partly during passage of the sector.

A wind turbine includes: a wind turbine rotor; a nacelle supporting the wind turbine rotor rotatably; a yaw rotation part configured to rotate the nacelle; and a yaw control part configured to operate the yaw rotation part in a yaw rewind mode of rotating the nacelle in such a direction that a yaw angle changes toward zero, if an absolute value of the yaw angle exceeds a threshold which is variable in accordance with a wind-velocity parameter representing a magnitude of a wind velocity. The threshold increases with an increase in the wind-velocity parameter.

A wind turbine is provided. The wind turbine includes a transformer having a low-voltage side and a high-voltage side. The transformer is configured to step up a voltage of the low-voltage side of the transformer to a voltage of an external grid. The wind turbine further includes an electrical power generating unit which is connected to the low-voltage side of the transformer and configured to feed an ac-power to the low-voltage side of the transformer. A charging device of the wind turbine is connected to the low-voltage side of the transformer and configured to charge the low-voltage side of the transformer when the generator does not feed ac-power to the low-voltage side of the transformer.

A method and system for improving the balance of a rotor in a wind turbine, including; determining blade load data associated with a selected rotor blade pair; determining, based on the blade load data, pitch imbalance data associated with the selected rotor blade pair, wherein the pitch imbalance data associated with a rotor blade pair is based on measurements of at least blade loading, rotor speed and wind speed; and, determining and applying pitch control inputs to one or both of the selected rotor blade pair in order to reduce the severity of the rotor imbalance.

The present invention relates to a method for controlling a wind power plant, the wind power plant comprising a plurality of wind turbine generators, each wind turbine generator comprising at least one power converter for providing active power and/or reactive power to an electrical grid, wherein the method is determining a required amount of reactive power provided by the plurality of wind turbine generators, and grouping the plurality of wind turbine generators into a first set of wind turbine generators and a second set of wind turbine generators based on a demand for reactive power; and supplying reactive power to the grid (20) from the first set of wind turbine generators and disconnecting the second set of wind turbine generators from the electrical grid (20) in response to a control demand, in order to minimize active power losses. The present invention also relates to a wind power plant arranged to perform the method.

A condition monitoring system for a wind turbine comprises: a sensor which senses a condition of a yaw bearing; a monitor device which generates a diagnosis parameter based on a detection result of the sensor; a sensor which senses a rotating angular velocity of a nacelle and that of a main shaft; and a data server which diagnoses a failure of the yaw bearing based on the diagnosis parameter. The data server diagnoses whether the yaw bearing has a failure, based on a variation of the diagnosis parameter from an initial value thereof when the nacelle has a rotating angular velocity within a non-zero, first prescribed range and the main shaft has a rotating angular velocity within a second prescribed range.

To provide a rotating pedestal capable of directing a wind power generation apparatus with high accuracy in the direction from which wind comes, regardless of the presence or absence of a duct is an object.

Provided is a rotating pedestal comprising: a bearing that rotatably supports a wind power generation apparatus; a control device that determines a rotational angle based on information regarding a wind direction and a wind speed in a vicinity of the wind power generation apparatus, the information being transmitted from an anemometer installed to be able to measure the wind direction and the wind speed in the vicinity of the wind power generation apparatus; and a motor that rotates the bearing based on the rotational angle determined by the control device.

The present invention provides a conveyance device for an energy collector such as a wind turbine, solar collector, or a combination thereof. The conveyance device is configured to orient the energy collector by moving the device to compensate for a change in the source of energy such as a change in power, direction, speed, location and a combination thereof. The conveyance device includes a track configured to be positioned near a support structure such as a telecommunications tower and first and second electrical contacts configured to electrically connect the energy collector to an electrical load. The conveyance device is also configured to receive an energy collector configured to be attached to the track such that the energy collector is movable relative to the track. In this manner, there is provided a device for adjusting the orientation of the wind turbine or solar collector such that it collects energy efficiently.

The present disclosure is directed to a system and method for controlling and/or upgrading aftermarket multivendor wind turbines. The system includes a turbine controller configured to control operations of the wind turbine, a safety device configured to provide a signal indicative of a health status of the safety device, and a secondary controller inserted between the safety device and the turbine controller. The secondary controller is configured to receive the signal from the safety device over a communication interface. As such, if the signal indicates a normal health status, the secondary controller is configured to send the signal to the turbine controller, i.e. maintain normal operation. Alternatively, if the signal indicates a poor health status, the secondary controller is configured to adjust the signal based at least in part on a signal bias to an adjusted signal and to provide the adjusted signal to the turbine controller.