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EP-4530464-B1 - METHODS FOR ESTIMATING VALUES OF WIND TURBINE OPERATIONAL PARAMETERS

EP4530464B1EP 4530464 B1EP4530464 B1EP 4530464B1EP-4530464-B1

Inventors

  • BOND-SMITH, LOUIS
  • ALBISU ISO, EFREN
  • Pineda Amo, Isaac

Dates

Publication Date
20260506
Application Date
20230926

Claims (11)

  1. A method (100) for estimating an actual value of an operational parameter (67) of a wind turbine (10) wherein the operational parameter is rotor speed and/or azimuth angle, the method (100) comprising: receiving (110) data related to the operational parameter (63) from a plurality of sensors (61) of the wind turbine (10); determining (120) which sensors of the plurality of sensors (61) are reliable and which sensors of the plurality of sensors (61) are unreliable; estimating (130) the actual value of the operational parameter (67) based on a mathematical model and on the data related to the operational parameter (63) received from the reliable sensors, wherein estimating (130) the actual value of the operational parameter (67) comprises combining data directly indicative of the operational parameter based on data received from the reliable sensors and further comprises performing an initial estimation of the actual value of the operational parameter with the mathematical model and correcting the initial estimation with the data directly indicative of the operational parameter based on data received from the reliable sensors; and using a Kalman filter for performing the initial estimation and for correcting the initial estimation.
  2. The method of claim 1, wherein determining (110) which sensors are unreliable comprises analyzing a noise in a range of measurements of a sensor (61), or analyzing a noise in a range of intermediate values (65).
  3. The method of claim 1 or 2, wherein determining (110) which sensors are unreliable comprises comparing two or more values directly indicative of the operational parameter based on measurements from different sensors (61) with an actual value of the operational parameter (67) estimated in one or more previous steps.
  4. The method of any of claims 1 - 3, further comprising using data related to the operational parameter (63) from two or more sensors of the plurality of sensors (61) to determine (120) which sensors are reliable and which sensors are unreliable.
  5. The method of any of claims 1 - 4, further comprising determining at least one intermediate value of the operational parameter (65) based on the measured data related to the operational parameter (63) measured by at least one sensor, and wherein estimating (120) the actual value of the operational parameter (67) comprises estimating the actual value (67) based on the at least one intermediate value (65).
  6. The method of any of claims 1 - 5, further comprising stopping measuring data with one or more of the unreliable sensors.
  7. The method of any of claims 1 - 6, wherein the operational parameter is a setpoint for controlling the wind turbine.
  8. The method of any of claims 1 - 7, wherein the plurality of sensors (61) comprises an encoder.
  9. A wind turbine controller (36) comprising a processor and a memory, wherein the memory comprises instructions that, when executed by the processor, cause the processor to: receive data related to an operational parameter (63) from a plurality of sensors (61) of the wind turbine (10), wherein the operational parameter is rotor speed and/or azimuth angle; determine which sensors of the plurality of sensors (61) are reliable and which sensors of the plurality of sensors (61) are unreliable; estimate an actual value of an operational parameter (67) based on a mathematical model and on the data related to the operational parameter (63) received from the reliable sensors, wherein estimating (130) the actual value of the operational parameter (67) comprises combining data directly indicative of the operational parameter based on data received from the reliable sensors and further comprises performing an initial estimation of the actual value of the operational parameter with the mathematical model and correcting the initial estimation with the data directly indicative of the operational parameter based on data received from the reliable sensors; and using a Kalman filter for performing the initial estimation and for correcting the initial estimation.
  10. A wind turbine (10) comprising a tower (15), a nacelle (16) on top of the tower (15), a rotor (18) connected to the nacelle (16), the rotor (18) comprising a hub (20) and a plurality of blades (22) connected to the hub (20), the wind turbine (10) further comprising the wind turbine controller (36) of claim 9.
  11. The wind turbine of claim 10, wherein the wind turbine (10) is an offshore wind turbine.

Description

The present disclosure relates to methods for estimating values of operational parameters of a wind turbine. The present disclosure further relates to wind turbine controllers and to wind turbines. BACKGROUND Modern wind turbines are commonly used to supply electricity into the electrical grid. Wind turbines of this kind generally comprise a tower and a rotor arranged on the tower. The rotor, which typically comprises a hub and a plurality of blades, is set into rotation under the influence of the wind on the blades. Said rotation generates a torque that is normally transmitted through a rotor shaft to a generator, either directly ("directly driven" or "gearless") or through the use of a gearbox. This way, the generator produces electricity which can be supplied to the electrical grid. The wind turbine hub may be rotatably coupled to a front of the nacelle. The wind turbine hub may be connected to a rotor shaft, and the rotor shaft may then be rotatably mounted in the nacelle using one or more rotor shaft bearings arranged in a frame inside the nacelle. The nacelle is a housing arranged on top of a wind turbine tower that may contain and protect the gearbox (if present) and the generator (if not placed outside the nacelle) and, depending on the wind turbine, further components such as a power converter, and auxiliary systems. A wind turbine includes a plurality of sensors. The sensors may monitor the wind turbine and for example help to check the health of the wind turbine or help to control how the wind turbine operates. For example, a wind turbine may comprise temperature sensors, vibration sensors, pressure sensors and others to check whether the wind turbine is damaged or not, or whether it is at risk. A wind turbine may also comprise sensors such as a wind speed sensor, a rotor speed sensor, an azimuth angle sensor and others, whose measurements may be used for controlling the wind turbine. Different ways of controlling a wind turbine may be implemented. Generated power may be controlled based on a tip speed ratio (TSR), a pitch angle and a torque. The TSR depends on the rotor speed, the rotor radius and the wind speed. Sensors may therefore be used in some examples to measure wind speed, rotor speed, pitch angle and/or torque, either to calculate setpoints for parameters, e.g. pitch angle and torque, and/or for checking that the setpoints are being followed. An anemometer may measure wind speed and wind direction, and the measured wind speed and wind direction may be used to e.g. calculate a suitable pitch angle of the wind turbine blades and/or a suitable generator torque. Similarly, an encoder arranged with a generator rotor may be used for measuring rotor speed, and the measured rotor speed may also be considered when calculating the pitch angle and/or the generator torque. Suitable actuators, e.g. pitch drives, yaw drives, power electronics and others, may then be activated to establish the desired behavior of the wind turbine. However, some wind turbine sensors may be noisy and unreliable. For example, the anemometer may not be reliable when measuring wind speed, as wind speed may only be measured at hub height and behind the rotor plane and thus disturbed by the rotor. Also, sensors may get damaged and fail. If a sensor is relevant for the operation and control of the wind turbine, the actuators may be overused, and vibrations and loads may increase. This may cause non-optimal operation of the wind turbine and a risk for the integrity of the wind turbine in severe cases. Documents considered during the patent prosecution are i.a.: EP 3 772 652 A1 and EP 3 760 861 A1. SUMMARY In an aspect of the present disclosure, a method for estimating an actual value of an operational parameter of a wind turbine is provided. The method comprises receiving data related to the operational parameter from a plurality of sensors of the wind turbine and determining which sensors of the plurality of sensors are reliable and which sensors of the plurality of sensors are unreliable. The method further comprises estimating the actual value of the operational parameter based on a mathematical model and on the data related to the operational parameter received from the reliable sensors. According to this aspect, a plurality of sensors can be used to improve accuracy in the determination of an operational parameter. It may be determined which of these wind turbine sensors provide reliable measurements. Measurements which are not deemed reliable may be excluded when estimating the actual value of a certain operational parameter of a wind turbine. The accuracy of the value of the estimated parameter may therefore be increased. Throughout this disclosure, the word (un)reliable with respect to the sensors may at least cover both accuracy and precision aspects. In some examples, a sensor may be deemed unreliable, i.e. not trustworthy, because it is deemed not accurate, or not precise, or not precise and not accurate. An operat