Method and apparatus for load measurement in a wind turbine
AssigneeGeneral Electric Company
InventorTill Hoffmann
Life of this patent
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Abstract
The present invention provides a connecting device adapted for connecting a hub and a main shaft of a wind turbine. The connecting device comprises at least one sensor bolt connecting the hub and the main shaft, wherein a stress detection element is mounted inside the sensor bolt. The stress detection element is adapted to detect a length variation of the sensor bolt and to output a sensor signal indicative of the length variation of the sensor bolt. A signal output device is used for outputting the sensor signal which is indicative of a stress applied to the sensor bolt.
Claims17
A connecting device configured to connect a hub and a main shaft of a wind turbine, comprising:
- at least one sensor bolt connecting the hub and the main shaft, comprising:
- a stress detection element mounted inside the sensor bolt, the stress detection element being configured to detect a length variation of the sensor bolt and to output a sensor signal as a function of the length variation of the sensor bolt;
- and
- a signal output device that outputs the sensor signal which is indicative of a stress applied to the sensor bolt,
- wherein the stress detection element is a distance measurement unit configured to measure a distance, in the longitudinal direction of the sensor bolt, between reference elements within the sensor bolt.
A wind turbine comprising a rotor comprising a main shaft and at least one rotor blade, and a hub, said wind turbine further comprising:
- a plurality of hub bolts that fix the main shaft to the hub,
- wherein at least one hub bolt is configured as a sensor bolt configured to detect a stress acting along its longitudinal axis and to output a sensor signal indicative of the detected stress;
- and
- a signal processing unit that processes the sensor signal such that a load applied at the wind turbine can be determined.
A method for reducing load in a wind turbine, the wind turbine comprising a rotor comprising a main shaft and at least one rotor blade with an adjustable pitch angle, wherein the method comprises:
- setting a pitch angle of the at least one rotor blade;
- detecting bending moments acting on the main shaft of the wind turbine;
- and
- adjusting the pitch angle of the at least one rotor blade on the basis of the detected bending moments such that the bending moments are reduced,
- wherein the main shaft and a hub of the wind turbine are connected by means of hub bolts, and wherein at least one hub bolt is configured as a sensor bolt comprising a stress detection element mounted inside the sensor bolt, and
- wherein the method further comprises determining the bending moments by a length variation of the sensor bolt.
Dependencies are inferred from the claim text.