Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D7/00—Controlling wind motors 
  • F03D7/02—Controlling wind motors  the wind motors having rotation axis substantially parallel to the air flow entering the rotor
  • F03D7/04—Automatic control; Regulation
  • F03D7/042—Automatic control; Regulation by means of an electrical or electronic controller
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D17/00—Monitoring or testing of wind motors, e.g. diagnostics
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D7/00—Controlling wind motors 
  • F03D7/02—Controlling wind motors  the wind motors having rotation axis substantially parallel to the air flow entering the rotor
  • F03D7/0296—Controlling wind motors  the wind motors having rotation axis substantially parallel to the air flow entering the rotor to prevent, counteract or reduce noise emissions
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2260/00—Function
  • F05B2260/82—Forecasts
  • F05B2260/821—Parameter estimation or prediction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2260/00—Function
  • F05B2260/96—Preventing, counteracting or reducing vibration or noise
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2270/00—Control
  • F05B2270/30—Control parameters, e.g. input parameters
  • F05B2270/334—Vibration measurements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2270/00—Control
  • F05B2270/30—Control parameters, e.g. input parameters
  • F05B2270/335—Output power or torque
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/70—Wind energy
  • Y02E10/72—Wind turbines with rotation axis in wind direction

Definitions

• the present invention relates to a method for measuring and controlling oscillations in a wind turbine coupled directly to a power mains, voltage and/or current being meas- ured at the mains connection and other values being optionally derived therefrom, such as apparent power, real power, reactive power, power factor, and cos( ⁇ ).
• a general wind turbine standstill under meteorological conditions that appear to facilitate the oscillation phenomena is not a practicable solution as it would be detrimental to the annual output of the wind turbine. It is therefore desirable to be capable of detecting the presence or absence of the oscillation phenomena and to be capable of adjusting the wind turbine control means so as to stop any occurring oscillation phenomenon so that the wind turbine may resume normal operation once the oscillation phenomenon has ceased.
• this prior art device is generally incapable of making the wind turbine resume normal operation once the oscillations have ceased, since the device is incorporated as a part of the emergency stop circuit of the wind turbine.
• vibration guards are known that may be incorporated in wind turbines. These guards permit detecting the presence of e.g. oscillations at a modest amplitude so that the dynamic load on the rotor blades can be kept within acceptable limits provided that the turbine can be stopped at the command of the vibration guard.
• these self-contained units are normally also incorporated in the emergency stop circuit of the wind turbine and thus also cannot bring the wind turbine into normal operation once the oscillations have ceased.
• This object is achieved by a method of the type mentioned initially, in which a spectrum analysis is performed of one or more of the measured values or any values derived therefrom, and wind turbine oscillation amplitudes are determined on the basis of the result of the spectrum analysis, and when the determined amplitude exceeds a certain value, countermeasures are taken by the wind turbine control system to reduce the amplitude of the oscillations.
• the dependent claims define appropriate embodiments of the method according to the invention. Particularly the dependent claims 4-1 0 define appropriate methods of counteracting for reducing the amplitude of the detected oscillations relating to the particular type of control system provided in a wind turbine.
• Fig. 1 illustrates a spectrum analysis of a recorded measurement of a wind turbine.
• a wind turbine control system is always adapted to make a number of measurements at the mains connection of the turbine. The measurements are made partly for operational reasons and partly for datalogging and statistics relating to the operation of the wind turbine. For that purpose the wind turbine control system is provided with a number of transducers for measuring voltage and current of the phases of the mains connection. Based on these primary measurements of voltage and current, the control system can calculate further secondary mains data, e.g. apparent power, real power, reactive power, power factor or cos( ⁇ ).
• Rotor blade oscillations lead to vibrations in the nacelle and rotor shaft of the wind turbine. Also in case of oscillations in opposite phase on two out of three rotor blades, vibrations can be measured in the nacelle and this may be caused by an asymmetry (a non-linear elasticity) caused by the oscillation amplitude involved.
• the rotor shaft torque will also comprise a component generated by rotor oscillations. Since the rotor blade oscillations generate a component in the torque of the rotor shaft, such component will also appear in the generator shaft torque and in a wind turbine with a generator coupled directly to the mains. It will therefore also appear in the primary measurements of current and/or voltage and in all the secondary mains data derived from the primary measurement values.
• the wind turbine control system performs a spectrum analysis of one or more of these sets of data and an averaging of a number of spectra.
• the fluctuations of the generator shaft torque generated by the oscillation phenomena will appear as a column or a narrow band of columns in the spectrum around the characteristic frequency f c of the oscillations as shown in Fig. 1 .
• the amplitude of the column in the spectrum indicates to the control system the amplitude of oscillations of the rotor blades and thereby provides a basis for decisions on the wind turbine operation.
• Axial tower oscillations i.e. oscillations in the longitudinal direction of the main shaft, will create fluctuations in the apparent wind velocity and thereby also fluctuations in the rotor and generator shaft torques. Like rotor blade oscillations such fluctuations can be detected in the primary measurement data and in the secondary measurement data derived from the primary measurement data.
• the fluctuations will appear as a column or a narrow band of columns in the spectrum at the characteristic frequency f 0 as shown in Fig. 1 .
• the amplitude of this column indicates the amplitude of the axial tower oscillations and thereby provides a basis for decisions on the wind turbine operation.
• a first type of countermeasure seeks to attenuate the oscillation phenomena by changing the rotational speed of the rotor, while a second type seeks to change the oscillation phenomena by changing the dynamic load of the wind turbine.
• the first type of countermeasures comprises the application of brakes. Whether the brakes will be applied until standstill depends on the characteristics of the brake system used. Certain types of tip brakes can only be reset at rotor standstill, so if such types are used, the rotor must be brought to a standstill before restart. However, if tip brakes can be reset during rotation, the control system can perform a restart "on the fly" of the wind turbine once the control system has detected that the oscillations have decayed.
• the second type of countermeasure wherein the control system counteracts by changing the dynamic load may in stall controlled wind turbines with a fixed pitch angle comprise the control system introducing a yaw angle error until the oscillation phenomena disappear, whereupon the turbine resumes normal operation without yaw angle error.
• the dynamic load can be changed in active stall wind turbines by changing the blade pitch angle in a negative direction until the oscillation phenomena disappear, whereupon the turbine resumes normal operation at the currently required pitch.
• the control system may also utilize introduction of a yaw angle error, if necessary.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Wind Motors (AREA)
• Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
• Vibration Prevention Devices (AREA)
• Buildings Adapted To Withstand Abnormal External Influences (AREA)
• Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
• Control Of Eletrric Generators (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8089123

Family Applications (1)

Country Status (11)

Cited By (25)

Families Citing this family (45)

Citations (5)

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• 1999
  • 1999-01-14 DE DE69901876T patent/DE69901876T2/de not_active Expired - Lifetime
  • 1999-01-14 CA CA002318386A patent/CA2318386C/en not_active Expired - Fee Related
  • 1999-01-14 AT AT99900876T patent/ATE219553T1/de not_active IP Right Cessation
  • 1999-01-14 WO PCT/DK1999/000020 patent/WO1999036695A1/en not_active Ceased
  • 1999-01-14 ES ES99900876T patent/ES2178872T3/es not_active Expired - Lifetime
  • 1999-01-14 AU AU20464/99A patent/AU2046499A/en not_active Abandoned
  • 1999-01-14 CN CN99802049A patent/CN1092760C/zh not_active Expired - Lifetime
  • 1999-01-14 DK DK99900876T patent/DK1045988T3/da active
  • 1999-01-14 EP EP99900876A patent/EP1045988B1/en not_active Expired - Lifetime
  • 1999-01-14 US US09/600,286 patent/US6525518B1/en not_active Expired - Lifetime
  • 1999-01-14 JP JP2000540370A patent/JP4226783B2/ja not_active Expired - Fee Related

Patent Citations (5)

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