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EP-4442990-B1 - METHOD FOR OPERATING A WIND TURBINE AND WIND TURBINE

EP4442990B1EP 4442990 B1EP4442990 B1EP 4442990B1EP-4442990-B1

Inventors

  • Niss, Michael
  • DROSSEL, DETLEF
  • LABORENZ, JACOB
  • Buller, Valeri
  • Phan-Graebitz, Björn

Dates

Publication Date
20260506
Application Date
20230404

Claims (11)

  1. Method for operating a wind turbine (100) comprising a rotor (10) with at least one rotor blade (1, 2, 3) and a setting system (31, 32) which is configured to change the operation of the wind turbine (100), the method comprising - (S7) providing first trigger information (Ia1) which is representative of whether the torsional movement of at least one rotor blade (1, 2, 3) exceeds a threshold, and, if this is the case, - (S8) generating a first output signal (OS1) which is configured to cause the setting system (31, 32) to change the operation of the wind turbine (100) in order to reduce the torsional movement of the at least one rotor blade (1, 2, 3), - providing at least one of: - (S1) first base information (II) which is representative of the pitch angle (β_i) of the at least one rotor blade (1, 2, 3), - (S2) second base information (I2) which is representative of the torsional bending moment (M_x,i) acting on the at least one rotor blade (1, 2, 3), - (S3, S4) third base information (I3) and/or fourth base information (I4) which are respectively representative of the edgewise bending moment (M_y,i) and/or of the flapwise bending moment (M_z,i) acting on the at least one rotor blade (1, 2, 3), - (S5) fifth base information (I5) which is representative of an angular acceleration of the at least one rotor blade (1, 2, 3), - wherein the first trigger information (Ia1) is determined depending on at least one of: the first base information (I1), the second base information (I2), the third base information (I3), the fourth base information (I4), the fifth base information (I5), - wherein determining the first trigger information (Ia1) comprises at least one of: - applying at least one filter to the first base information (I1) in order to extract an oscillation of the pitch angle (β_i) of the at least one rotor blade (1, 2, 3) with the torsional eigenfrequency of the at least one rotor blade (1, 2, 3) and determining whether an amplitude of the oscillation with the torsional eigenfrequency exceeds a threshold, - applying at least one filter to the second base information (I2) in order to extract an oscillation of the torsional bending moment (M_x,i) of the at least one rotor blade (1, 2, 3) with the torsional eigenfrequency and determining whether an amplitude of the oscillation with the torsional eigenfrequency exceeds a threshold, - applying at least one filter to the third (I3) and/or fourth (I4) base information in order to extract an oscillation of the edgewise bending moment (M_y,i) and/or of the flapwise bending moment (M_z,i) of the at least one rotor blade (1, 2, 3) with the torsional eigenfrequency of the at least one rotor blade (1, 2, 3) and determining whether an amplitude of the oscillation with the torsional eigenfrequency exceeds a threshold, - applying at least one filter to the fifth base information (I5) in order to extract an oscillation of the angular acceleration of the at least one rotor blade (1, 2, 3) with the torsional eigenfrequency and determining whether an amplitude of the oscillation with the torsional eigenfrequency exceeds a threshold.
  2. Method according to claim 1, wherein - the first base information (I1) is determined depending on measurements taken with the help of a first sensor system (11), - the first sensor system (11) comprises at least one encoder sensor.
  3. Method according to claim 1 or 2, wherein - the second base information (I2) is determined depending on measurements taken with the help of a second sensor system (12), - the second sensor system (12) comprises at least one strain sensor for measuring the torsional bending moment (M_x,i) of the at least one rotor blade (1, 2, 3).
  4. Method according to any one of the preceding claims, wherein - the third base information (I3) and/or the fourth base information (I4) are determined depending on measurements taken with the help of a third sensor system (13) and/or a fourth sensor system (14), - the third sensor system (13) comprises at least one strain sensor for measuring the edgewise bending moment (M_y,i) of the at least one rotor blade (1, 2, 3) and/or the fourth sensor system (14) comprises at least one strain sensor for measuring the flapwise bending moment (M_z,i) of the at least one rotor blade (1, 2, 3).
  5. Method according to any one of the preceding claims, further comprising - wherein the fifth base information (I5) is determined depending on measurements taken with the help of a fifth sensor system (15), - wherein the fifth sensor system (15) comprises at least one acceleration sensor for measuring the angular acceleration of the at least one rotor blade (1, 2, 3).
  6. Method according to any one of the preceding claims, wherein - the setting system (31, 32) is configured to execute at least two different measures for reducing the torsional movement of the at least one rotor blade (1, 2, 3), - the first output signal (OS1) is configured to cause the setting system (31, 32) to execute a first measure for reducing the torsional movement of the at least one rotor blade (1, 2, 3), - the method further comprises - (S9) providing a second trigger information (Ia2) which is representative of whether the torsional movement of at least one rotor blade (1, 2, 3) exceeds a threshold after the first measure has been executed, and, if this is the case, - (S10) generating a second output signal (OS2) which is configured to cause the setting system (31, 32) to execute a second measure for reducing the torsional movement of the at least one rotor blade (1, 2, 3), wherein - each of the first measure and the second measure is one, but not the same, of: changing the pitch angle (β_i) of the at least one rotor blade (1, 2, 3), changing the speed of rotation of the rotor (10) without stopping the rotation of the rotor (10), changing the electrical power output of the wind turbine (100), shutting down the wind turbine (100).
  7. Computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method of any one of claims 1 to 6.
  8. Computer-readable data carrier having the computer program of claim 7 stored thereon.
  9. Control device (30) comprising at least one processor configured to perform the method of any one of claims 1 to 6.
  10. Control system (40) for operating a wind turbine (100) having a rotor (10) with at least one rotor blade (1, 2, 3) and a setting system (31, 32) for changing the operation of the wind turbine (100), the control system (40) comprising - at least one sensor system (11 to 15) configured to take measurements (P11 to P15) with the help of which it is determinable whether a torsional movement of at least one rotor blade (1, 2, 3) exceeds a threshold, - the control device (30) according to claim 9, wherein - the control device (30) is signally connectable to the at least one sensor system (11 to 15) in order to provide the control device (30) with the measurements (P11 to P15) of the at least one sensor system (11 to 15), - the control device (30) is signally connectable to the setting system (31, 32) in order to provide the setting system (31, 32) with the first output signal (OS1) of the control device (30) so that the setting system (31, 32) changes the operation of the wind turbine (100) depending on the first output signal (OS1).
  11. Wind turbine (100) comprising - a rotor (10) with at least one rotor blade (1, 2, 3), - a setting system (31, 32) for changing the operation of the wind turbine (100), - the control system (40) according to claim 10.

Description

The present disclosure relates to a method for operating a wind turbine. Furthermore, the present disclosure relates to a computer program, a computer-readable data carrier, a control device, a control system and a wind turbine. Wind turbines are widely known and are used to convert wind energy into electrical energy. The lengths of the rotor blades used in such wind turbines have increased in recent years. Torsional vibrations of the rotor blades, which can be caused by stall or by another source of excitation, lead to a risk of structural damage of the rotor blades. Furthermore, torsional vibrations of the rotor blades cause undesired loads on other wind turbine structural components, such as the pitch bearings, the rotor hub, the drive train, the machine frame, the yaw bearing and/or the tower, thus leading to a risk of structural damage of said wind turbine components. Document US 2017/356425 A1 relates to improvements to wind turbines and, in particular, to measuring dynamic twist of a wind turbine blade and determining a torsional load on the wind turbine blade. Document US 2017/335828 A1 relates to controlling and/or regulating and monitoring, respectively, the operation of wind turbines and the components used for this purpose such as acceleration sensors and/or the corresponding components of a wind turbine. Document CN 114 718 811 A relates to the technical field of wind power generation measurement and control, in particular to a self-adaptive control method for monitoring the state of a fan blade based on a GPS. Document US 2019/154001 A1 relates to a method and system for controlling a wind turbine and, more specifically, to identify and manage unacceptable vibrations in blades of the wind turbine. One object to be achieved is to provide an improved method for operating a wind turbine, for example a method which increases the lifetime of the rotor blade and/or other components of the wind turbine. Further objects to be achieved are to provide a computer program, a computer-readable data carrier, a control device and a control system for providing such a method as well as a wind turbine with which this method can be executed. First, the method for operating a wind turbine is specified. According to the invention, the method is for operating a wind turbine having a rotor with at least one rotor blade and a setting system which is configured to change the operation of the wind turbine. The method comprises a step in which first trigger information is provided, wherein the first trigger information is representative of whether the torsional movement of at least one rotor blade exceeds a threshold. If this is the case, i.e. if the first trigger information is representative of the torsional movement of at least one rotor blade to exceed the threshold, a first output signal is generated which is configured to cause the setting system to change the operation of the wind turbine in order to reduce the torsional movement of the at least one rotor blade, in accordance with claim 1. The present invention is, inter alia, based on the recognition that stalling blades, especially when the rotor blades are covered with ice, can lead to torsional blade vibrations and this can lead to a dangerous operation. With the present invention, torsional vibrations are detected and the wind turbine is set to a safe operation if the torsional vibrations exceed a threshold. The method specified herein is, in particular, a computer implemented method, i.e. is performed by a computer or a processor. Herein, when information is representative of a certain quantity or certain quantities, this means that the quantity or quantities can be extracted from the information, either directly, or the quantity/quantities can at least be derived from the information. In other words, the quantity/quantities is/are stored in the information, or at least data are stored in the information, from which the quantity/quantities can be derived or determined or calculated, respectively. Furthermore, here and in the following, information is, in particular, electronic information, like electronic data. The first trigger information is representative of whether the torsional movement of at least one rotor blade, in particular a torsional vibration of at least one rotor blade, exceeds a threshold. This threshold is herein also referred to as first threshold. The first threshold is, for example, a predetermined threshold. Particularly, the first trigger information is representative of whether the torsional movement exceeds the first threshold while the rotor is rotating. By way of example, the first trigger information is either 0 or 1, with 0 meaning that the first threshold is not exceeded and 1 meaning that the first threshold is exceeded. The first trigger information may be determined repeatedly, e.g. periodically. For example, the first trigger information is determined with a frequency of at least 1 Hz or at least 10 Hz or at least 100 Hz. Th