WO2018059259A1 - Method and system of yaw control of wind turbines in a wind turbine farm - Google Patents

Method and system of yaw control of wind turbines in a wind turbine farm Download PDF

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Publication number
WO2018059259A1
WO2018059259A1 PCT/CN2017/102049 CN2017102049W WO2018059259A1 WO 2018059259 A1 WO2018059259 A1 WO 2018059259A1 CN 2017102049 W CN2017102049 W CN 2017102049W WO 2018059259 A1 WO2018059259 A1 WO 2018059259A1
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WO
WIPO (PCT)
Prior art keywords
wind
control unit
data
wind turbine
remote control
Prior art date
Application number
PCT/CN2017/102049
Other languages
French (fr)
Inventor
Lei Tong
Lin Chen
Feng Zhang
Carsten Hein Westergaard
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Envision Energy (Jiangsu) Co., Ltd.
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Application filed by Envision Energy (Jiangsu) Co., Ltd. filed Critical Envision Energy (Jiangsu) Co., Ltd.
Publication of WO2018059259A1 publication Critical patent/WO2018059259A1/en

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    • 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 
    • 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
    • F03D7/048—Automatic control; Regulation by means of an electrical or electronic controller controlling wind farms
    • 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
    • F03D7/0204—Controlling wind motors  the wind motors having rotation axis substantially parallel to the air flow entering the rotor for orientation in relation to wind direction
    • 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
    • F05B2270/32—Wind speeds
    • 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
    • F05B2270/321—Wind directions
    • 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 system for controlling a wind turbine in a wind turbine farm, wherein the wind turbine farm comprises a plurality of wind turbines arranged relative to each other, each of the wind turbines is connected to a remote control unit via a communication link and comprises a yaw system configured to yaw the nacelle into a yaw angle, wherein the remote control unit is configured to control the yaw movement of the wind turbines.
  • the present invention also relates to a method for controlling a wind turbine in a wind turbine farm, the wind turbine farm comprising a plurality of wind turbines arranged relative to each other, each of the wind turbines is in communication with a remote control unit and yaws the nacelle into a yaw angle, wherein the remote control unit controls the yaw movement of the wind turbines.
  • Modern wind turbines are often arranged together in a wind turbine farm wherein the individual wind turbines are positioned relative to each other in a predetermined pattern.
  • the performance of the wind turbine farm can be monitored via a monitoring system positioned at a remote location, wherein the monitoring system comprises a control unit capable of communicating with the wind turbine farm via a suitable communication link, e.g. a Supervisory Control and Data Acquisition (SCADA) -link.
  • SCADA Supervisory Control and Data Acquisition
  • the yaw movement is performed by a wind turbine yaw system controlled by a local control unit which uses a wind direction measurement to track the wind direction as it changes or to yaw the wind turbine rotor out of the wind.
  • the wind profile in the wind turbine farm may at the same time show both uniformity and inconsistency due to local climate systems and terrain topologies at the geographic location of the wind turbine farm.
  • the wind direction measurements of nearby wind turbines may be substantially the same.
  • the wind direction measurements of nearby wind turbines may vary within a relative short time period. If each wind turbine is operated independently, then the overall energy loss due to yaw misalignment and the amount of unnecessary yaw actions are increased.
  • Another known problem is a wake or shadow effect caused by wind turbines located upwind relative to the incoming wind direction.
  • the upwind wind turbines reduce the wind speed of the passing wind and may generate a more turbulent airflow compared to the relative free airflow hitting the upwind wind turbines. This may in turn lead to increased loads and stresses in the downwind wind turbines and a reduced power production.
  • One way to solve this problem is to increase the distances between individual wind turbines in the layout of the wind turbine farm or to include wind turbines with different sized wind turbine blades or wind turbines having different power ratings.
  • Another way of solving this problem is to lower the maximum design parameters of the wind turbines, however, each wind turbine is thus operated in a non-optimal setting and, thus, the overall power production is lowered.
  • US 2014/0037447 A1 discloses a yaw control scheme for a wind turbine farm wherein a remote control system adjusts the individual yaw angles if the detected wake effect between at least two selected wind turbines exceeds a threshold.
  • Information of the wind turbine farm topology and the wind direction is used by the remote control system to select a group of wind turbines.
  • Short-term data which are defined by a maximum of ten seconds, are transmitted from the selected wind turbines to the remote control system.
  • the control system predicts wind conditions using simulations or aerodynamic models and calculates the predicted total power output of the selected wind turbines.
  • the control system determines the optimal yaw angle for each selected wind turbine which is predicted to produce the maximum total power output.
  • Individual yaw angle commands are afterwards sent to each individual yaw system in the selected wind turbines.
  • the selected wind turbines then adjust their individual yaw angles according to the received yaw angle commands. It can be difficult to accurately detect if a wind turbine is affected by a wake effect or not, particularly if the relative free airflow has a very turbulent profile.
  • An object of the invention is to provide an alternative system and method for operating a wind turbine farm that solves the above-mentioned problems.
  • Another object of the invention is to provide a system and method that reduces the overall energy loss and the overall yaw actions of the wind turbines.
  • a further object of the invention is to provide a system and method that prevents extreme loadings of the selected wind turbines.
  • An object of the invention is achieved by a method for controlling a wind turbine in a wind turbine farm, comprising a plurality of wind turbines and a remote control unit configured to communicate with said plurality of wind turbines, each wind turbine comprises at least a yaw system configured to yaw a nacelle relative to a wind turbine tower and at least one operating sensor configured to measure at least one operating parameter, the remote control unit comprises at least one database, wherein the method comprises the steps of:
  • the step of dividing said plurality of wind turbines into at least one group comprises collecting long term data, e.g. long term operating data, from the wind turbine farm, wherein the plurality of wind turbines are divided into said at least one group based on at least the long term data.
  • long term data e.g. long term operating data
  • upwind wind turbine is defined as a wind turbine which is only influenced by the relative free airflow of the incoming wind.
  • downstream wind turbine is defined as a wind turbine which is influenced by the turbulent and/or reduced airflow derived from one or more upwind wind turbines and, optionally, also from other downwind wind turbines.
  • command is defined as any control value or control set-point used in the wind turbine to regulate a corresponding operating parameter.
  • yaw angle command refers to the target yaw angle relative to the wind direction in which the rotor is positioned during yawing.
  • long term data is defined as any parameters measured over a relative long time period, such as days, months or years, compared to short term data.
  • short term data is defined as any parameters measured over a relative short time period, such as seconds, minutes or hours, compared to the long term data.
  • operating data refers to any operating parameters measured directly on the wind turbine or another unit in the wind turbine farm.
  • wind data refers to any wind parameters measured on or relative to the wind turbine or another unit in the wind turbine farm. The definition of these relative terms is well-known within the technical field of wind energy.
  • This provides an improved method for controlling the yaw angles of the individual wind turbines in a wind turbine farm.
  • This control method eliminates the need for determining or estimating a wake effect between an upwind wind turbine and a downwind wind turbine. This allows the overall energy production, e.g. total power output, of the wind turbine farm to be increased and, thus, reduce the overall energy loss due to misalignment of the individual wind turbines. This also allows that the yaw movement can be controlled in a collective manner for selective groups, thereby reducing the overall yaw actions of each wind turbine.
  • the present control method is suitable for remote yaw control of a wind turbine farm, wherein the wind turbine farm comprises a plurality of wind turbines having a yaw system for yawing the nacelle and the rotor into position relative to the wind direction.
  • Operating data i.e. one or more operating parameters, of the wind turbine farm are measured and transmitted to the remote control unit via a suitable communications link.
  • the measured operating data are then stored in the database for further processing in the control unit.
  • the measured operating data may be stored in a local database in the wind turbine and then transmitted to the remote control unit.
  • the operating data may optionally be processed, e.g. filtered, by a local control unit in the wind turbine before being transmitted to the remote control unit. This allows the remote control unit to collect operating data from the wind turbine farm, e.g. from the individual wind turbines, sub-stations or other units located in the wind turbine farm.
  • the yaw angle command is a collective yaw angle command for said at least one group, wherein the nacelles of said at least two wind turbines are yawed according to said collective yaw angle command.
  • the operating data may comprise long term operating data and short term operating data.
  • the operating data may in example, but not limited to, include pitch angle of wind turbine blades, power output, yaw angle of nacelle, rotor speed, rotor torque, operating temperature, load signals or other suitable operating parameters.
  • the individual wind turbines are then divided into one, two, three or more groups based on the long term operating data, wherein each group comprises at least two selected wind turbines.
  • the long term operating data may be combined with other types of data in order to determine the grouping of the wind turbines, as described later. This allows the remote control unit to divide the wind turbines into suitable groups which can then be controlled in a collective manner.
  • the method further comprises the step of:
  • short term data e.g. short term operating data from the at least one group
  • the short term operating data may then be analysed and evaluated by the remote control unit in order to generate a collective yaw angle command for each group.
  • the short term operating data of a selected group may be used to generate the collective yaw angle command for that selected group.
  • the short term operating data may suitably be analysed in real time or substantially real time for optimal yaw control. This also allows for a faster detection and correction of yaw misalignments between the current yaw angle of the nacelle and the wind direction which, in turn, reduces the overall energy/power loss.
  • the remote control unit may alternatively analyse all available short term data for the selected group or only analyse a selective amount of the available short term data, e.g. the operating data.
  • the short term operating data of the wind turbines in the selected group may be combined with the short term wind data of these wind turbines.
  • the wind data may in example, but not limited to, include wind direction, wind speed, air density, ambient temperature or other suitable wind parameters. This allows the remote control unit to take into account various factors, such as maximum power production and/or maximum load situations, when generating the collective yaw angle command for the selected group.
  • the collective yaw angle command may be determined directly by simply analysing the measured short term data, e.g. the short term operating data, of that group. Alternatively, the measured short term data may be analysed to determine a target power output or wind direction which is then used to calculate the collective yaw angle command. The collective yaw angle command can thus be generated directly or indirectly depending on the short term data.
  • the collective yaw angle command may be generated by identifying the best performing wind turbine, e.g. having the highest energy yield or power out, of the selected group. The yaw angle of this best performing wind turbine may then be used as the collective yaw angle command. Alternatively, a weighted mean wind direction of the group may be used to generate the collective yaw angle command. In a further alternative, a least mean square (LMS) algorithm or a support vector machine algorithm may be used to determine the collective yaw angle command. In these algorithms, the measurements, e.g. the short term data, are inputted as vector quantities.
  • LMS least mean square
  • the method further comprises the step of:
  • the nacelles of the at least two wind turbines are yawed collectively according to the collective yaw angle command.
  • the selected group of wind turbines may be controlled according to the collective yaw angle command when suitable wind or operating conditions exist.
  • the wind or operating condition may be defined by one or more thresholds.
  • the remote control unit, or the local control unit, may detect if such suitable conditions exists or not.
  • the step of detecting whether a predetermined condition is present or not comprises at least one of the following steps:
  • the above-mentioned group may be yawed collectively according to the collective yaw angle command if suitable conditions are present.
  • the remote control unit or local control unit, may determine a mean wind speed and/or wind speed variances of the selected group based on the measurements, e.g. the measured wind speed.
  • the mean wind speed and/or wind speed variances may be determined within a predetermined time period, e.g. between 1 minute and 10 minutes.
  • the mean wind speed may then be compared to a first threshold, e.g. between 4 m/sand 10 m/s.
  • the wind speed variances e.g. the range thereof, may then be compared to another first threshold, e.g. up to 10 m/s.
  • the first threshold for the mean wind speed and/or wind speed variances may also be selected dependent of a particular configuration of that group. If the mean wind speed and/or wind speed variances is/are equal to or below the first threshold, then suitable wind conditions exist and the wind turbines in the selected group may be yawed according to the collective yaw angle command. This allows the control unit to evaluate consistency of the relative wind speed of the selected group in order to detect any abnormal wind profiles, faulty sensors or other abnormal situations.
  • the remote control unit may alternatively or additionally determine a mean wind direction and/or wind direction variances of the selected group based on the measurements, e.g. the measured wind direction.
  • the mean wind direction and/or wind direction variances may be determined within the above-mentioned predetermined time period.
  • the mean wind direction may then be used to determine a yaw error relative to the current yaw angle which, in turn, is compared to a second threshold, e.g. up to 3 degrees.
  • the wind speed variances e.g. the range thereof, may then be compared to another second threshold, e.g. up to 0.2 degrees.
  • the control unit may evaluate consistency of the relative wind direction of the selected group in order to also detect any abnormal wind profiles, faulty sensors or other abnormal situations.
  • the remote control unit may alternatively or additionally compare a selected operating parameter, e.g. the rotor speed, the rotor torque or another suitable operating parameter, to a third threshold.
  • a load signal may optionally be calculated or estimated based the measurements which, in turn, is compared to the third threshold. If the selected operating parameter or load signal is equal to or below the third threshold, then suitable operating conditions exist and the wind turbines in the selected group may further be yawed according to the collective yaw angle command. This allows the control unit to evaluate and detect any safety issues of the selected group, such as maximum load situations or other abnormal operation situations.
  • the method further comprises the step of:
  • each of the nacelles of said at least two wind turbines is yawed individually according to said individual yaw angle command.
  • the above-mentioned group yaws individually according to individual yaw angle commands.
  • the remote control unit, or the local control unit in a selected wind turbine may generate an individual yaw angle for that selected wind turbine.
  • the individual yaw angle command may thus be generated in each wind turbine of the group by the local control unit, or transmitted from the remote control unit to each wind turbine via the communications link.
  • the individual yaw angle command may be determined directly by simply analysing the measured short term data, e.g. the short term operating data, of that wind turbine. Alternatively, the measured short term data of that wind turbine may be analysed to determine a target power output or wind direction which is then used to calculate the individual yaw angle command. The individual yaw angle command can thus be generated directly or indirectly depending on the short term data. Other algorithms may be used to generate the individual yaw angle command.
  • the collective and individual yaw angle commands may be generated parallel, wherein the remote control unit, or the local control unit, may select which of these yaw angle commands should be used. This allows the wind turbines in that group to be yawed collectively or individually depending on whether suitable conditions exist or not.
  • the at least one group is further determined based on at least one of the following:
  • the long term operating data described above may be combined with long term wind data measured in or relative to the wind turbine farm.
  • the wind data may in example, but not limited to, include wind direction, wind speed, air density, ambient temperature or other suitable wind parameters. This allows the remote control unit to collect and analyse the available long term data of the wind turbine farm in order to divide the individual wind turbines into one or more groups.
  • the wind data i.e. one or more wind parameters, of the wind turbine farm are measured and transmitted to the remote control unit via the communications link.
  • the measured wind data are then stored in the database for further processing in the remote control unit.
  • the measured wind data may be stored in a local database in the wind turbine and then transmitted to the remote control unit.
  • the wind data may optionally be processed, e.g. filtered, by the local control unit in the wind turbine before being transmitted to the remote control unit.
  • factors may alternatively or additionally be combined with the long term data when dividing the wind turbines into groups.
  • factors may in example, but not limited to, be terrain topologies of the wind turbine farm or the selected group, seasonal changes in the measured metrological conditions or other suitable factors.
  • the long term data e.g. the wind direction, wind speed, air pressure, ambient temperature or other suitable parameters
  • the long term data e.g. the wind direction, wind speed, air pressure, ambient temperature or other suitable parameters
  • these correlations may then be evaluated in order to identify which wind turbines produce substantially the same measurements, i.e. have the highest correlations.
  • These wind turbines may afterwards be grouped together in a selected group.
  • the method further comprises the steps of:
  • operating data e.g. the long term operating data, stored in the at least one database
  • the database comprising at least the long term data, e.g. the long term operating data, may be updated after each run of the above-mentioned process. Alternatively, the database may be updated upon request or periodically. After the database has been updated, a subsequent run of the process may be performed in order to determine if individual wind turbines should be redivided into new groups or not.
  • the short term data and/or the long term data may be measured continuously or periodically and then stored directly in the database of the remote control unit or in a local database before being transmitted to the remote control unit.
  • the local control unit may control the communication with the remote control unit and control the yaw movement of the yaw system.
  • All the individual wind turbines of the wind turbine farm may be divided into one or more groups, wherein the process described above may be performed for each group.
  • An object of the invention is also achieved by a system for controlling a wind turbine in a wind turbine farm, comprising a plurality of wind turbines and a remote control unit, each wind turbine comprises at least a yaw system configured to yaw a nacelle relative to a wind turbine tower and at least one operating sensor configured to measure at least one operating parameter, the remote control unit is configured to communicate with said plurality of wind turbines via a communications link, the remote control unit further comprises at least one database in which operating data from the wind turbine farm are stored, characterised in that the remote control unit is configured to collect long term data, e.g. long term operating data, from the wind turbine farm, wherein the remote control unit is further configured to divide said plurality of wind turbines into at least one group based on the long term data.
  • each wind turbine comprises at least a yaw system configured to yaw a nacelle relative to a wind turbine tower and at least one operating sensor configured to measure at least one operating parameter
  • the remote control unit is configured to communicate with said
  • This provides an improved yaw control system of a wind turbine farm, wherein the control method described above can be implemented in a remote control unit, such as a remote monitoring or control station.
  • the present yaw control system does not rely on a measured or estimated wake effect to divide the individual wind turbine into groups. Instead, the present yaw control system uses long term data to divide the wind turbines into group. This allows the overall energy loss of the wind turbine farm to be reduced and the amount of yaw actions of each wind turbine to be reduced.
  • Each wind turbine comprises a wind turbine tower, a nacelle, a rotor with two or more wind turbine blades, wherein a yaw system is arranged between the wind turbine tower and the nacelle so that the nacelle and rotor can be yawed into a target yaw angle.
  • the yaw movement is controlled by the local control unit.
  • the remote control unit, and local control unit comprises a controller, e.g. a microprocessor or programmable logic circuit (PLC) , and a communications module configured to communicate with a matching communications module of another unit.
  • the communications link may a SCADA-link or another suitable link.
  • the remote control unit comprises a group dividing module configured to analyse the long term data and divide the wind turbines into groups as described above.
  • the group dividing module may use statistical analysis or another suitable algorithm to select which wind turbines should be grouped together.
  • the remote control unit is further configured to collect short term data, e.g. short term operating data, from said at least one group, and to generate a collective yaw angle command of said at least one group based on the short term data.
  • short term data e.g. short term operating data
  • the remote control unit may comprise a data collecting module configured to collect operating data and, optionally, wind data from the wind turbine farm.
  • the data collecting module may be connected to one or more databases in which the measurements are stored.
  • the remote control unit may further comprise a yaw angle command module configured to analyse the short term data and generate a collective yaw angle command as described above.
  • the yaw angle command module may use statistical analysis or another suitable algorithm to determine a target power output or yaw angle which is then transformed into a suitable collective yaw angle command.
  • the remote control unit or a local control unit in said at least one group is further configured to determine whether a predetermined condition is present or not.
  • the local control unit may comprise a condition detecting module configured to determine if suitable conditions, i.e. a predetermined condition, exist or not as described above.
  • the condition detecting module may use one or more first, second or third thresholds to generate a positive signal, e.g. binary one, indicating that suitable conditions exists or a negative signal, e.g. binary zero, indicating that suitable conditions do not exist.
  • the local control unit, or remote control unit may further comprise another yaw angle command module configured to generate an individual yaw angle command as described above.
  • This yaw angle command module may be any suitable algorithm to generate the individual yaw angle command.
  • the remote control unit or the local control unit is further configured to selectively control the yaw movement of the nacelle of said one wind turbine according to the collective yaw angle command or an individual yaw angle command.
  • the positive or negative signal from the condition detecting module may be transmitted to both yaw angle command modules and used to determine which yaw angle command should be transmitted further to the respective yaw system.
  • a separate priority module may receive both the positive or negative signal and the collective and individual yaw angle commands and may select between the respective yaw angle commands. This enables the yaw control system to selectively control the yaw movement of the wind turbines in each group.
  • the remote control unit is further configured to update the operating data, e.g. the long term operating data, stored in said at least one database, and to optionally redivide the plurality of wind turbines in said at least one group based on the updated operating data.
  • the operating data e.g. the long term operating data
  • the remote control unit is further configured to update the operating data, e.g. the long term operating data, stored in said at least one database, and to optionally redivide the plurality of wind turbines in said at least one group based on the updated operating data.
  • the remote control unit may additionally comprise an updating module configured to update the long term data stored in the database.
  • the updating module may be connected to the group dividing module via the controller which, when receiving a signal from the updating module, performs another run of the process to determine if the wind turbines should be divided into new groups.
  • Fig. 1 shows an exemplary embodiment of a wind turbine park in communication with a remote control system according to the invention
  • Fig. 2 shows an exemplary configuration of the remote control system
  • Fig. 3 shows the communications between the individual wind turbines and the remote control unit
  • Fig. 4 shows a first method of controlling the yaw angle in a wind turbine farm
  • Fig. 5 shows a second method of controlling the yaw angle in a wind turbine farm.
  • Fig. 1 shows an exemplary embodiment of a wind turbine farm comprising a plurality of individual wind turbines 1, here only four wind turbines are shown.
  • Each wind turbine 1 comprises a wind turbine tower 2 and a nacelle 3 arranged on top of the wind turbine tower 2, wherein a yaw system 4 is used to yaw the nacelle 3 relative to the wind turbine tower 2 and into yaw angle relative to a wind direction.
  • the nacelle 3 is rotatably connected to a hub 5 and a number of wind turbine blades 6, here three wind turbine blades are shown.
  • the wind turbine blades 6 are connected to the hub 5 via a pitch system 7 configured to pitch the wind turbine blade 6 into a pitch angle relative to the wind direction.
  • Each of the wind turbines 1 further comprises a local control unit 8, at least one operating sensor 9 and at least one wind sensor 10, e.g. a LIDAR unit.
  • the operating sensor 9 and the wind sensor 10 are electrically connected to the local control unit 8.
  • the local control unit 8 is configured to communicate with a remote control system via a communications link.
  • the remote control system comprises a remote control unit 11 electrically connected to at least one database 12.
  • the local control unit 8 is configured to transmit operating data and/or wind data from the wind turbine 1 to the remote control unit 11 for storage in the database 12.
  • the remote control unit 11 is configured to generate a yaw control command (see fig. 3) to the local control unit 8 for controlling the yaw movement of the yaw system 4.
  • FIG. 2 shows a block diagram of an exemplary configuration of the remote control system.
  • the remote control unit 11 comprises a controller 13 connected to a communications module 14 configured to communicate with a matching communications module in the local control unit 8.
  • the controller 13 controls the internal communications between the individual modules of the remote control unit 11.
  • the controller 13 is further connected to a data collecting module 15 configured to collect operating data and wind data from the wind turbine park.
  • the data collecting module 15 is further configured to store the operating data and the wind data in the database 12.
  • a group dividing module 16 is further connected to the controller 13 and configured to analyse the stored operating and wind data, e.g. the long term data, and to divide the wind turbines 1 into one or more groups (see fig. 3) .
  • An updating module 17 is configured to update the stored data, e.g. the long term data, via the data collecting module 15.
  • the updating module 17 is further configured to update the current grouping of the wind turbines 1 via the group dividing module 16.
  • a yaw angle command module 18 is configured to generate a collective yaw angle command (see fig. 3) for a selected group based on the stored operating and wind data, e.g. the short term data, .
  • the remote control unit 11 further comprises another yaw angle command module 19 used to generate an individual yaw angle command (see fig. 3) for each wind turbine 1 in the selected group.
  • the remote control unit 11 finally comprises a condition detecting module 20 configured to detect whether suitable wind conditions or operating conditions exist or not. The output of this condition detecting module 20 is used to select which yaw angle command should be transmitted to the local control unit 8.
  • Fig. 3 shows a block diagram of the communications between the remote control 11 and the respective wind turbines 1 in the wind turbine park.
  • Long term data 21, e.g. long term operating data, are measured and transmitted to the remote control unit 11 for subsequent analysis and evaluation.
  • the remote control unit 11 analyses these long term data 21 to determine a suitable grouping strategy for the individual wind turbines 1.
  • the long term data 21 is optionally combined with other factors 22, e.g. long term wind data or terrain topologies, when determining the grouping strategy.
  • the individual wind turbines 1 is divided 23 into a predetermined number of groups 24, each comprising at least two wind turbines 1.
  • the remote control unit 11 analyses the short term data 25 of a selected group 24 in order to generate a collective yaw angle command 26 for the selected group and, optionally, an individual yaw angle command 27 for each individual wind turbine 1 of the selected group 24.
  • a selective yaw angle command 26, 27 is then transmitted to the local control unit 8 in each wind turbine 1 of the selected group 24.
  • Fig. 4 shows a first method of controlling the yaw movement in a wind turbine park according to the invention. Initially, long term data 21 of the respective sensors 9, 10 is collected 28 and stored in the database 12.
  • This long term data 21 is subsequently analysed in order to determine a grouping strategy.
  • the individual wind turbines 1 are then divided 23 into one or more groups 24 as described above. The dividing process is repeated until all wind turbines 1 are divided into a group.
  • short term data of the respective sensors 9, 10 is collected 29 and stored in the database 12.
  • This short term data 25 is then analysed in real time to determine a wind speed or wind speed variance and/or a wind direction or wind direction variance of the selected group 24.
  • This signal is then used to determine 30 the collective yaw angle command 26.
  • the conditions of the selected group 24 may be monitored 31 in parallel to or after determining 30 the collective yaw angle command 26. If suitable wind or operating conditions exist, then the collective yaw angle command 26 is transmitted to each wind turbine 1 in the selected group 24. The yaw angle movement is thus controlled collectively via the remote control unit 11.
  • the stored long term data in the database 12 is finally updated 32 via the updating module 17.
  • the updating module 17 activates the group dividing module 15 in order to determine if the dividing strategy should be updated or not. If no update is needed, the steps 29-31 are repeated. If an update is needed, then another run of the process is performed.
  • Fig. 5 shows a second method of controlling the yaw movement in a wind turbine park according to the invention. Step 23, 28, 29 and 31 are the same as described above.
  • the short term data 25 for each individual wind turbine 1 is analysed in real time and individual yaw angle commands 27 are generated 33. These individual yaw angle commands 27 may be generated in parallel to step 30 or only after determining that suitable wind or operating conditions do not exist.
  • the individual yaw angle commands 27 are afterwards transmitted to each wind turbine 1 in the selected group 24.
  • the yaw angle movement is thus controlled individually via the remote control unit 11.
  • the database 12 is then updated 32 as described above.
  • the remote control unit 11 continues to monitor 31, or in regular time intervals, the conditions of the selected group 24 until suitable wind or operating conditions exist.
  • suitable wind or operating conditions exist again, then the collective yaw angle command 26 is transmitted to each wind turbine 1 in the selected group 24 and the yaw movement is controlled collectively as described above.
  • the process described in relation to fig. 4 is repeated.

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Abstract

A system and method thereof for controlling wind turbines in a wind turbine farm are provided, wherein each wind turbine (1) comprises a yaw system (4) for yawing the nacelle (3) into a yaw angle. A remote control unit (11) collects operating data and wind data from the wind turbine farm and stores the measurements in a database (12). The remote control unit (11) uses the long term data (21) and, optionally, other factors to divide the wind turbines (1) into groups (24). A collective yaw angle command (26) is generated based on the short term data (25) of a selected group and, optionally, transmitted to a local control unit (8) in each wind turbine (1) of a selected group. The remote control unit (11), or the local control unit (8), determines if predetermined conditions exist or not. If such predetermined conditions exist, then the selected group is yawed according to the collective yaw angle command (26). If not, then the selected group is yawed according to individual yaw angel commands (27). Thus, the system and method can reduce the overall energy loss and the overall yaw actions of the wind turbines and can also prevent extreme loadings of the selected wind turbines.

Description

Method and system of yaw control of wind turbines in a wind turbine farm Field of the Invention
The present invention relates to a system for controlling a wind turbine in a wind turbine farm, wherein the wind turbine farm comprises a plurality of wind turbines arranged relative to each other, each of the wind turbines is connected to a remote control unit via a communication link and comprises a yaw system configured to yaw the nacelle into a yaw angle, wherein the remote control unit is configured to control the yaw movement of the wind turbines.
The present invention also relates to a method for controlling a wind turbine in a wind turbine farm, the wind turbine farm comprising a plurality of wind turbines arranged relative to each other, each of the wind turbines is in communication with a remote control unit and yaws the nacelle into a yaw angle, wherein the remote control unit controls the yaw movement of the wind turbines.
Background of the Invention
Modern wind turbines are often arranged together in a wind turbine farm wherein the individual wind turbines are positioned relative to each other in a predetermined pattern. The performance of the wind turbine farm can be monitored via a monitoring system positioned at a remote location, wherein the monitoring system comprises a control unit capable of communicating with the wind turbine farm via a suitable communication link, e.g. a Supervisory Control and Data Acquisition (SCADA) -link.
The yaw movement is performed by a wind turbine yaw system controlled by a local control unit which uses a wind direction measurement to track the wind direction as it changes or to yaw the wind turbine rotor out of the wind. The wind profile in the wind turbine farm may at the same time show both uniformity and inconsistency due to local climate systems and terrain topologies at the geographic location of the wind turbine farm. In certain conditions, such as relative free airflows and relative large wind speeds, the wind direction measurements of nearby wind turbines may be substantially the same. In certain other conditions, such as relative small wind speeds where the local terrain topology affects the wind characteristics, the wind direction  measurements of nearby wind turbines may vary within a relative short time period. If each wind turbine is operated independently, then the overall energy loss due to yaw misalignment and the amount of unnecessary yaw actions are increased.
Another known problem is a wake or shadow effect caused by wind turbines located upwind relative to the incoming wind direction. The upwind wind turbines reduce the wind speed of the passing wind and may generate a more turbulent airflow compared to the relative free airflow hitting the upwind wind turbines. This may in turn lead to increased loads and stresses in the downwind wind turbines and a reduced power production. One way to solve this problem is to increase the distances between individual wind turbines in the layout of the wind turbine farm or to include wind turbines with different sized wind turbine blades or wind turbines having different power ratings. Another way of solving this problem is to lower the maximum design parameters of the wind turbines, however, each wind turbine is thus operated in a non-optimal setting and, thus, the overall power production is lowered.
US 2014/0037447 A1 discloses a yaw control scheme for a wind turbine farm wherein a remote control system adjusts the individual yaw angles if the detected wake effect between at least two selected wind turbines exceeds a threshold. Information of the wind turbine farm topology and the wind direction is used by the remote control system to select a group of wind turbines. Short-term data, which are defined by a maximum of ten seconds, are transmitted from the selected wind turbines to the remote control system. The control system predicts wind conditions using simulations or aerodynamic models and calculates the predicted total power output of the selected wind turbines. The control system then determines the optimal yaw angle for each selected wind turbine which is predicted to produce the maximum total power output. Individual yaw angle commands are afterwards sent to each individual yaw system in the selected wind turbines. The selected wind turbines then adjust their individual yaw angles according to the received yaw angle commands. It can be difficult to accurately detect if a wind turbine is affected by a wake effect or not, particularly if the relative free airflow has a very turbulent profile.
There exists a need for an improved yaw control of wind turbines which can be implemented into a control system of a wind turbine farm.
Object of the Invention
An object of the invention is to provide an alternative system and method for operating a wind turbine farm that solves the above-mentioned problems.
Another object of the invention is to provide a system and method that reduces the overall energy loss and the overall yaw actions of the wind turbines.
A further object of the invention is to provide a system and method that prevents extreme loadings of the selected wind turbines.
Description of the Invention
An object of the invention is achieved by a method for controlling a wind turbine in a wind turbine farm, comprising a plurality of wind turbines and a remote control unit configured to communicate with said plurality of wind turbines, each wind turbine comprises at least a yaw system configured to yaw a nacelle relative to a wind turbine tower and at least one operating sensor configured to measure at least one operating parameter, the remote control unit comprises at least one database, wherein the method comprises the steps of:
- measuring wind data and at least one operating parameter of said each wind turbine,
- dividing said plurality of wind turbines into at least one group, the at least one group comprising at least two wind turbines,
- determining a yaw angle command,
- transmitting said yaw angle command from said remote control unit to said at least two wind turbines,
- yawing said nacelle according to the received yaw angle command, characterised in that
- the step of dividing said plurality of wind turbines into at least one group comprises collecting long term data, e.g. long term operating data, from the wind turbine farm, wherein the plurality of wind turbines are divided into said at least one group based on at least the long term data.
The term “upwind wind turbine” is defined as a wind turbine which is only influenced by the relative free airflow of the incoming wind. The term “downwind wind turbine”  is defined as a wind turbine which is influenced by the turbulent and/or reduced airflow derived from one or more upwind wind turbines and, optionally, also from other downwind wind turbines.
The general term “command” is defined as any control value or control set-point used in the wind turbine to regulate a corresponding operating parameter. The specific term “yaw angle command” refers to the target yaw angle relative to the wind direction in which the rotor is positioned during yawing.
The general term “long term data” is defined as any parameters measured over a relative long time period, such as days, months or years, compared to short term data. The general term “short term data” is defined as any parameters measured over a relative short time period, such as seconds, minutes or hours, compared to the long term data. The specific term “operating data” refers to any operating parameters measured directly on the wind turbine or another unit in the wind turbine farm. The specific term “wind data” refers to any wind parameters measured on or relative to the wind turbine or another unit in the wind turbine farm. The definition of these relative terms is well-known within the technical field of wind energy.
This provides an improved method for controlling the yaw angles of the individual wind turbines in a wind turbine farm. This control method eliminates the need for determining or estimating a wake effect between an upwind wind turbine and a downwind wind turbine. This allows the overall energy production, e.g. total power output, of the wind turbine farm to be increased and, thus, reduce the overall energy loss due to misalignment of the individual wind turbines. This also allows that the yaw movement can be controlled in a collective manner for selective groups, thereby reducing the overall yaw actions of each wind turbine.
The present control method is suitable for remote yaw control of a wind turbine farm, wherein the wind turbine farm comprises a plurality of wind turbines having a yaw system for yawing the nacelle and the rotor into position relative to the wind direction.
Operating data, i.e. one or more operating parameters, of the wind turbine farm are measured and transmitted to the remote control unit via a suitable communications  link. The measured operating data are then stored in the database for further processing in the control unit. Alternatively, the measured operating data may be stored in a local database in the wind turbine and then transmitted to the remote control unit. The operating data may optionally be processed, e.g. filtered, by a local control unit in the wind turbine before being transmitted to the remote control unit. This allows the remote control unit to collect operating data from the wind turbine farm, e.g. from the individual wind turbines, sub-stations or other units located in the wind turbine farm.
According to one embodiment, the yaw angle command is a collective yaw angle command for said at least one group, wherein the nacelles of said at least two wind turbines are yawed according to said collective yaw angle command.
The operating data may comprise long term operating data and short term operating data. The operating data may in example, but not limited to, include pitch angle of wind turbine blades, power output, yaw angle of nacelle, rotor speed, rotor torque, operating temperature, load signals or other suitable operating parameters.
The individual wind turbines are then divided into one, two, three or more groups based on the long term operating data, wherein each group comprises at least two selected wind turbines. The long term operating data may be combined with other types of data in order to determine the grouping of the wind turbines, as described later. This allows the remote control unit to divide the wind turbines into suitable groups which can then be controlled in a collective manner.
According to a special embodiment, the method further comprises the step of:
- collecting short term data, e.g. short term operating data from the at least one group,
- wherein said collective yaw angle command is determined based on said short term data.
The short term operating data may then be analysed and evaluated by the remote control unit in order to generate a collective yaw angle command for each group. In example, the short term operating data of a selected group may be used to generate the  collective yaw angle command for that selected group. The short term operating data may suitably be analysed in real time or substantially real time for optimal yaw control. This also allows for a faster detection and correction of yaw misalignments between the current yaw angle of the nacelle and the wind direction which, in turn, reduces the overall energy/power loss.
The remote control unit may alternatively analyse all available short term data for the selected group or only analyse a selective amount of the available short term data, e.g. the operating data. The short term operating data of the wind turbines in the selected group may be combined with the short term wind data of these wind turbines. The wind data may in example, but not limited to, include wind direction, wind speed, air density, ambient temperature or other suitable wind parameters. This allows the remote control unit to take into account various factors, such as maximum power production and/or maximum load situations, when generating the collective yaw angle command for the selected group.
The collective yaw angle command may be determined directly by simply analysing the measured short term data, e.g. the short term operating data, of that group. Alternatively, the measured short term data may be analysed to determine a target power output or wind direction which is then used to calculate the collective yaw angle command. The collective yaw angle command can thus be generated directly or indirectly depending on the short term data.
The collective yaw angle command may be generated by identifying the best performing wind turbine, e.g. having the highest energy yield or power out, of the selected group. The yaw angle of this best performing wind turbine may then be used as the collective yaw angle command. Alternatively, a weighted mean wind direction of the group may be used to generate the collective yaw angle command. In a further alternative, a least mean square (LMS) algorithm or a support vector machine algorithm may be used to determine the collective yaw angle command. In these algorithms, the measurements, e.g. the short term data, are inputted as vector quantities.
According to one embodiment, the method further comprises the step of:
- detecting whether a predetermined condition is present or not,
- wherein, if said predetermined condition is present, the nacelles of the at least two wind turbines are yawed collectively according to the collective yaw angle command.
The selected group of wind turbines may be controlled according to the collective yaw angle command when suitable wind or operating conditions exist. The wind or operating condition may be defined by one or more thresholds. The remote control unit, or the local control unit, may detect if such suitable conditions exists or not.
According to another special embodiment, the step of detecting whether a predetermined condition is present or not comprises at least one of the following steps:
- comparing a mean wind speed or wind speed variances to a predetermined first threshold,
- comparing a mean wind direction or wind direction variances to a predetermined second threshold, or
- comparing a selected operating parameter to a predetermined third threshold.
The above-mentioned group may be yawed collectively according to the collective yaw angle command if suitable conditions are present. The remote control unit, or local control unit, may determine a mean wind speed and/or wind speed variances of the selected group based on the measurements, e.g. the measured wind speed. The mean wind speed and/or wind speed variances may be determined within a predetermined time period, e.g. between 1 minute and 10 minutes. The mean wind speed may then be compared to a first threshold, e.g. between 4 m/sand 10 m/s. The wind speed variances, e.g. the range thereof, may then be compared to another first threshold, e.g. up to 10 m/s. The first threshold for the mean wind speed and/or wind speed variances may also be selected dependent of a particular configuration of that group. If the mean wind speed and/or wind speed variances is/are equal to or below the first threshold, then suitable wind conditions exist and the wind turbines in the selected group may be yawed according to the collective yaw angle command. This allows the control unit to evaluate consistency of the relative wind speed of the  selected group in order to detect any abnormal wind profiles, faulty sensors or other abnormal situations.
The remote control unit, or local control unit, may alternatively or additionally determine a mean wind direction and/or wind direction variances of the selected group based on the measurements, e.g. the measured wind direction. The mean wind direction and/or wind direction variances may be determined within the above-mentioned predetermined time period. The mean wind direction may then be used to determine a yaw error relative to the current yaw angle which, in turn, is compared to a second threshold, e.g. up to 3 degrees. The wind speed variances, e.g. the range thereof, may then be compared to another second threshold, e.g. up to 0.2 degrees. If the yaw error is above the second threshold and/or the wind direction variances are equal to or below the second threshold, then suitable wind conditions exist and the wind turbines in the selected group may also be yawed according to the collective yaw angle command. This allows the control unit to evaluate consistency of the relative wind direction of the selected group in order to also detect any abnormal wind profiles, faulty sensors or other abnormal situations.
Furthermore, the remote control unit, or local control unit, may alternatively or additionally compare a selected operating parameter, e.g. the rotor speed, the rotor torque or another suitable operating parameter, to a third threshold. A load signal may optionally be calculated or estimated based the measurements which, in turn, is compared to the third threshold. If the selected operating parameter or load signal is equal to or below the third threshold, then suitable operating conditions exist and the wind turbines in the selected group may further be yawed according to the collective yaw angle command. This allows the control unit to evaluate and detect any safety issues of the selected group, such as maximum load situations or other abnormal operation situations.
According to a further special embodiment, the method further comprises the step of:
- further determining an individual yaw angle command for each of the at least two wind turbines in said at least one group,
- wherein, if said predetermined condition is not present, each of the nacelles of said at least two wind turbines is yawed individually according to said individual yaw angle command.
If no suitable conditions are detected, then the above-mentioned group yaws individually according to individual yaw angle commands. The remote control unit, or the local control unit in a selected wind turbine, may generate an individual yaw angle for that selected wind turbine. The individual yaw angle command may thus be generated in each wind turbine of the group by the local control unit, or transmitted from the remote control unit to each wind turbine via the communications link.
The individual yaw angle command may be determined directly by simply analysing the measured short term data, e.g. the short term operating data, of that wind turbine. Alternatively, the measured short term data of that wind turbine may be analysed to determine a target power output or wind direction which is then used to calculate the individual yaw angle command. The individual yaw angle command can thus be generated directly or indirectly depending on the short term data. Other algorithms may be used to generate the individual yaw angle command.
The collective and individual yaw angle commands may be generated parallel, wherein the remote control unit, or the local control unit, may select which of these yaw angle commands should be used. This allows the wind turbines in that group to be yawed collectively or individually depending on whether suitable conditions exist or not.
According to one embodiment, the at least one group is further determined based on at least one of the following:
- terrain topology of the wind turbine farm,
- a mean wind direction of the wind turbine farm,
- a mean wind speed of the wind turbine farm,
- seasonal changes in metrological conditions, or
- correlation between measurements, e.g. wind data performed on each wind turbine.
The long term operating data described above may be combined with long term wind data measured in or relative to the wind turbine farm. The wind data may in example, but not limited to, include wind direction, wind speed, air density, ambient temperature or other suitable wind parameters. This allows the remote control unit to collect and analyse the available long term data of the wind turbine farm in order to divide the individual wind turbines into one or more groups.
The wind data, i.e. one or more wind parameters, of the wind turbine farm are measured and transmitted to the remote control unit via the communications link. The measured wind data are then stored in the database for further processing in the remote control unit. Alternatively, the measured wind data may be stored in a local database in the wind turbine and then transmitted to the remote control unit. The wind data may optionally be processed, e.g. filtered, by the local control unit in the wind turbine before being transmitted to the remote control unit.
Other factors may alternatively or additionally be combined with the long term data when dividing the wind turbines into groups. Such factors may in example, but not limited to, be terrain topologies of the wind turbine farm or the selected group, seasonal changes in the measured metrological conditions or other suitable factors.
Optionally, the long term data, e.g. the wind direction, wind speed, air pressure, ambient temperature or other suitable parameters, may be analysed in order to determine the correlation between the measurements of the individual wind turbines. These correlations may then be evaluated in order to identify which wind turbines produce substantially the same measurements, i.e. have the highest correlations. These wind turbines may afterwards be grouped together in a selected group.
According to one embodiment, the method further comprises the steps of:
- transmitting said at least one operating parameter to the remote control unit,
- updating operating data, e.g. the long term operating data, stored in the at least one database, and
- optionally, redividing the plurality of wind turbines into the at least one group based on the updated operating data.
The database comprising at least the long term data, e.g. the long term operating data, may be updated after each run of the above-mentioned process. Alternatively, the database may be updated upon request or periodically. After the database has been updated, a subsequent run of the process may be performed in order to determine if individual wind turbines should be redivided into new groups or not.
The short term data and/or the long term data may be measured continuously or periodically and then stored directly in the database of the remote control unit or in a local database before being transmitted to the remote control unit. The local control unit may control the communication with the remote control unit and control the yaw movement of the yaw system.
All the individual wind turbines of the wind turbine farm may be divided into one or more groups, wherein the process described above may be performed for each group.
An object of the invention is also achieved by a system for controlling a wind turbine in a wind turbine farm, comprising a plurality of wind turbines and a remote control unit, each wind turbine comprises at least a yaw system configured to yaw a nacelle relative to a wind turbine tower and at least one operating sensor configured to measure at least one operating parameter, the remote control unit is configured to communicate with said plurality of wind turbines via a communications link, the remote control unit further comprises at least one database in which operating data from the wind turbine farm are stored, characterised in that the remote control unit is configured to collect long term data, e.g. long term operating data, from the wind turbine farm, wherein the remote control unit is further configured to divide said plurality of wind turbines into at least one group based on the long term data.
This provides an improved yaw control system of a wind turbine farm, wherein the control method described above can be implemented in a remote control unit, such as a remote monitoring or control station. The present yaw control system does not rely on a measured or estimated wake effect to divide the individual wind turbine into groups. Instead, the present yaw control system uses long term data to divide the wind turbines into group. This allows the overall energy loss of the wind turbine farm to be reduced and the amount of yaw actions of each wind turbine to be reduced.
Each wind turbine comprises a wind turbine tower, a nacelle, a rotor with two or more wind turbine blades, wherein a yaw system is arranged between the wind turbine tower and the nacelle so that the nacelle and rotor can be yawed into a target yaw angle. The yaw movement is controlled by the local control unit.
The remote control unit, and local control unit, comprises a controller, e.g. a microprocessor or programmable logic circuit (PLC) , and a communications module configured to communicate with a matching communications module of another unit. The communications link may a SCADA-link or another suitable link.
The remote control unit comprises a group dividing module configured to analyse the long term data and divide the wind turbines into groups as described above. The group dividing module may use statistical analysis or another suitable algorithm to select which wind turbines should be grouped together.
According to one embodiment, the remote control unit is further configured to collect short term data, e.g. short term operating data, from said at least one group, and to generate a collective yaw angle command of said at least one group based on the short term data.
The remote control unit may comprise a data collecting module configured to collect operating data and, optionally, wind data from the wind turbine farm. The data collecting module may be connected to one or more databases in which the measurements are stored.
The remote control unit may further comprise a yaw angle command module configured to analyse the short term data and generate a collective yaw angle command as described above. The yaw angle command module may use statistical analysis or another suitable algorithm to determine a target power output or yaw angle which is then transformed into a suitable collective yaw angle command.
According to a special embodiment, the remote control unit or a local control unit in said at least one group is further configured to determine whether a predetermined condition is present or not.
The local control unit, or remote control unit, may comprise a condition detecting module configured to determine if suitable conditions, i.e. a predetermined condition, exist or not as described above. The condition detecting module may use one or more first, second or third thresholds to generate a positive signal, e.g. binary one, indicating that suitable conditions exists or a negative signal, e.g. binary zero, indicating that suitable conditions do not exist.
The local control unit, or remote control unit, may further comprise another yaw angle command module configured to generate an individual yaw angle command as described above. This yaw angle command module may be any suitable algorithm to generate the individual yaw angle command.
According to another special embodiment, the remote control unit or the local control unit is further configured to selectively control the yaw movement of the nacelle of said one wind turbine according to the collective yaw angle command or an individual yaw angle command.
Dependent on the particular configuration of the yaw control system, the positive or negative signal from the condition detecting module may be transmitted to both yaw angle command modules and used to determine which yaw angle command should be transmitted further to the respective yaw system. Alternatively, a separate priority module may receive both the positive or negative signal and the collective and individual yaw angle commands and may select between the respective yaw angle commands. This enables the yaw control system to selectively control the yaw movement of the wind turbines in each group.
According to one embodiment, the remote control unit is further configured to update the operating data, e.g. the long term operating data, stored in said at least one database, and to optionally redivide the plurality of wind turbines in said at least one group based on the updated operating data.
The remote control unit may additionally comprise an updating module configured to update the long term data stored in the database. The updating module may be connected to the group dividing module via the controller which, when receiving a signal from the updating module, performs another run of the process to determine if the wind turbines should be divided into new groups.
Description of the Drawing
The invention is described by example only and with reference to the drawings, wherein:
Fig. 1 shows an exemplary embodiment of a wind turbine park in communication with a remote control system according to the invention,
Fig. 2 shows an exemplary configuration of the remote control system,
Fig. 3 shows the communications between the individual wind turbines and the remote control unit,
Fig. 4 shows a first method of controlling the yaw angle in a wind turbine farm, and
Fig. 5 shows a second method of controlling the yaw angle in a wind turbine farm.
In the following text, the figures will be described one by one, and the different parts and positions seen in the figures will be numbered with the same numbers in the different figures. Not all parts and positions indicated in a specific figure will necessarily be discussed together with that figure.
Position number list
1. Wind turbines
2. Wind turbine tower
3. Nacelle
4. Yaw system
5. Hub
6. Wind turbine blades
7. Pitch system
8. Local control unit
9. Operating sensor
10. Wind sensor
11. Remote control unit
12. Database
13. Controller
14. Communications module
15. Data collecting module
16. Group dividing module
17. Updating module
18. Collective yaw angle command module
19. Individual yaw angle command module
20. Condition detecting module
21. Long term data
22. Other factors
23. Dividing wind turbine into group
24. Groups
25. Short term data
26. Collective yaw angle command
27. Individual yaw angle command
28. Collecting long term data
29. Collecting short term data
30. Determining collective yaw angle command
31. Monitoring conditions
32. Updating long term data
33. Determining individual yaw angle commands
Detailed Description of the Invention
Fig. 1 shows an exemplary embodiment of a wind turbine farm comprising a plurality of individual wind turbines 1, here only four wind turbines are shown. Each wind turbine 1 comprises a wind turbine tower 2 and a nacelle 3 arranged on top of the wind turbine tower 2, wherein a yaw system 4 is used to yaw the nacelle 3 relative to the wind turbine tower 2 and into yaw angle relative to a wind direction. The nacelle 3 is rotatably connected to a hub 5 and a number of wind turbine blades 6, here three wind turbine blades are shown. The wind turbine blades 6 are connected to the hub 5 via a pitch system 7 configured to pitch the wind turbine blade 6 into a pitch angle relative to the wind direction.
Each of the wind turbines 1 further comprises a local control unit 8, at least one operating sensor 9 and at least one wind sensor 10, e.g. a LIDAR unit. The operating sensor 9 and the wind sensor 10 are electrically connected to the local control unit 8. The local control unit 8 is configured to communicate with a remote control system via a communications link. The remote control system comprises a remote control unit 11 electrically connected to at least one database 12.
The local control unit 8 is configured to transmit operating data and/or wind data from the wind turbine 1 to the remote control unit 11 for storage in the database 12. The remote control unit 11 is configured to generate a yaw control command (see fig. 3) to the local control unit 8 for controlling the yaw movement of the yaw system 4.
Figure 2 shows a block diagram of an exemplary configuration of the remote control system. The remote control unit 11 comprises a controller 13 connected to a communications module 14 configured to communicate with a matching communications module in the local control unit 8. The controller 13 controls the internal communications between the individual modules of the remote control unit 11.
The controller 13 is further connected to a data collecting module 15 configured to collect operating data and wind data from the wind turbine park. The data collecting module 15 is further configured to store the operating data and the wind data in the database 12.
A group dividing module 16 is further connected to the controller 13 and configured to analyse the stored operating and wind data, e.g. the long term data, and to divide the wind turbines 1 into one or more groups (see fig. 3) .
An updating module 17 is configured to update the stored data, e.g. the long term data, via the data collecting module 15. The updating module 17 is further configured to update the current grouping of the wind turbines 1 via the group dividing module 16.
A yaw angle command module 18 is configured to generate a collective yaw angle command (see fig. 3) for a selected group based on the stored operating and wind data, e.g. the short term data, . The remote control unit 11 further comprises another yaw angle command module 19 used to generate an individual yaw angle command (see fig. 3) for each wind turbine 1 in the selected group.
The remote control unit 11 finally comprises a condition detecting module 20 configured to detect whether suitable wind conditions or operating conditions exist or not. The output of this condition detecting module 20 is used to select which yaw angle command should be transmitted to the local control unit 8.
Fig. 3 shows a block diagram of the communications between the remote control 11 and the respective wind turbines 1 in the wind turbine park. Long term data 21, e.g. long term operating data, are measured and transmitted to the remote control unit 11 for subsequent analysis and evaluation.
The remote control unit 11 then analyses these long term data 21 to determine a suitable grouping strategy for the individual wind turbines 1. The long term data 21 is optionally combined with other factors 22, e.g. long term wind data or terrain topologies, when determining the grouping strategy. The individual wind turbines 1 is divided 23 into a predetermined number of groups 24, each comprising at least two wind turbines 1.
Afterwards, the remote control unit 11 analyses the short term data 25 of a selected group 24 in order to generate a collective yaw angle command 26 for the selected  group and, optionally, an individual yaw angle command 27 for each individual wind turbine 1 of the selected group 24. A selective  yaw angle command  26, 27 is then transmitted to the local control unit 8 in each wind turbine 1 of the selected group 24.
Fig. 4 shows a first method of controlling the yaw movement in a wind turbine park according to the invention. Initially, long term data 21 of the respective sensors 9, 10 is collected 28 and stored in the database 12.
This long term data 21 is subsequently analysed in order to determine a grouping strategy. The individual wind turbines 1 are then divided 23 into one or more groups 24 as described above. The dividing process is repeated until all wind turbines 1 are divided into a group.
Afterwards, short term data of the respective sensors 9, 10 is collected 29 and stored in the database 12. This short term data 25 is then analysed in real time to determine a wind speed or wind speed variance and/or a wind direction or wind direction variance of the selected group 24. This signal is then used to determine 30 the collective yaw angle command 26. The conditions of the selected group 24 may be monitored 31 in parallel to or after determining 30 the collective yaw angle command 26. If suitable wind or operating conditions exist, then the collective yaw angle command 26 is transmitted to each wind turbine 1 in the selected group 24. The yaw angle movement is thus controlled collectively via the remote control unit 11. The stored long term data in the database 12 is finally updated 32 via the updating module 17.
The updating module 17 activates the group dividing module 15 in order to determine if the dividing strategy should be updated or not. If no update is needed, the steps 29-31 are repeated. If an update is needed, then another run of the process is performed.
Fig. 5 shows a second method of controlling the yaw movement in a wind turbine park according to the invention.  Step  23, 28, 29 and 31 are the same as described above.
If suitable wind or operating conditions do not exist, then the short term data 25 for each individual wind turbine 1 is analysed in real time and individual yaw angle commands 27 are generated 33. These individual yaw angle commands 27 may be  generated in parallel to step 30 or only after determining that suitable wind or operating conditions do not exist.
The individual yaw angle commands 27 are afterwards transmitted to each wind turbine 1 in the selected group 24. The yaw angle movement is thus controlled individually via the remote control unit 11. The database 12 is then updated 32 as described above.
The remote control unit 11 continues to monitor 31, or in regular time intervals, the conditions of the selected group 24 until suitable wind or operating conditions exist. When suitable wind or operating conditions exist again, then the collective yaw angle command 26 is transmitted to each wind turbine 1 in the selected group 24 and the yaw movement is controlled collectively as described above. Alternatively, the process described in relation to fig. 4 is repeated.

Claims (12)

  1. A method for controlling a wind turbine (1) in a wind turbine farm, comprising a plurality of wind turbines (1) and a remote control unit (11) configured to communicate with said plurality of wind turbines (1) , each wind turbine (1) comprises at least a yaw system (4) configured to yaw a nacelle (3) relative to a wind turbine tower (2) and at least one operating sensor (9) configured to measure at least one operating parameter, the remote control unit (11) comprises at least one database (12) , wherein the method comprises the steps of:
    - measuring wind data and at least one operating parameter of said each wind turbine (1) ,
    - dividing (23) said plurality of wind turbines (1) into at least one group (24) , the at least one group (24) comprising at least two wind turbines (1) ,
    - determining a yaw angle command (30, 33) ,
    - transmitting said yaw angle command from said remote control unit (11) to said at least two wind turbines (1) ,
    - yawing said nacelle (3) according to the received yaw angle command, characterised in that the step of dividing (23) said plurality of wind turbines (1) into at least one group (24) comprises
    - collecting long term data (28) , e.g. long term operating data, from the wind turbine farm, wherein the plurality of wind turbines (1) are divided into said at least one group (24) based on at least the long term data (21) , and wherein the yaw angle command is a collective yaw angle command (26) for said at least one group (24) , wherein the nacelles (3) of said at least two wind turbines (1) are yawed according to said collective yaw angle command (26) , wherein the method further comprises a step of:
    - collecting short term data (29) , e.g. short term operating data from the at least one group (24) , where said collective yaw angle command (26) is determined based on said short term data (25) .
  2. The method according to claim 1, characterised in that the method further comprises the step of:
    - detecting whether a predetermined condition is present or not,
    - wherein, if said predetermined condition is present, the nacelles (3) of the at least two wind turbines (1) are yawed collectively according to the collective yaw angle command (26) .
  3. The method according to claim 2, characterised in that the step of detecting whether a predetermined condition is present or not comprises at least one of the following steps:
    - comparing a mean wind speed or wind speed variances to a predetermined first threshold,
    - comparing a mean wind direction or wind direction variances to a predetermined second threshold, or
    - comparing a selected operating parameter to a predetermined third threshold.
  4. The method according to claim 2 or 3, characterised in that the method further comprises the step of:
    - further determining (33) an individual yaw angle command (27) for each of the at least two wind turbines (1) in said at least one group (24) ,
    - wherein, if said predetermined condition is not present, each of the nacelles (3) of said at least two wind turbines (1) is yawed individually according to said individual yaw angle command (27) .
  5. The method according to one or more of claims 1 to 4, characterised in that the at least one group (24) is further determined based on at least one of the following:
    - terrain topology of the wind turbine farm,
    - a mean wind direction of the wind turbine farm,
    - a mean wind speed of the wind turbine farm,
    - seasonal changes in metrological conditions, or
    - correlation between measurements, e.g. wind data performed on each wind turbine (1) .
  6. The method according to one or more of claims 1 to 5, characterised in that the method further comprises the steps of:
    - transmitting said at least one operating parameter to the remote control unit (11) ,
    - updating operating data, e.g. the long term operating data (32) , stored in the at least one database (12) , and
    - optionally, re-dividing the plurality of wind turbines (1) into the at least one group (24) based on the updated operating data.
  7. The method according to one or more of claims 1 to 6, wherein collecting long term data (28) is collecting measured long term data, and collecting short term data (29) is collecting measured short term data.
  8. A system for controlling a wind turbine (1) in a wind turbine farm, comprising a plurality of wind turbines (1) and a remote control unit (11) , each wind turbine (1) comprises at least a yaw system (4) configured to yaw a nacelle (3) relative to a wind turbine tower (2) and at least one operating sensor (9) configured to measure at least one operating parameter, the remote control unit (11) is configured to communicate with said plurality of wind turbines (1) via a communications link, the remote control unit (11) further comprises at least one database (12) in which operating data from the wind turbine farm are stored, characterised in that wherein the remote control unit (11) is configured to collect long term data (21) , e.g. long term operating data, from the wind turbine farm, wherein the remote control unit (11) is further configured to divide said plurality of wind turbines (1) into at least one group (24) based on the long term data (21) , wherein the remote control unit (11) is further configured to collect short term data (25) , e.g. short term operating data, from said at least one group (24) , and to generate a collective yaw angle command (26) of said at least one group (24) based on the short term data (25) .
  9. The system according to claim 8, characterised in that the remote control unit (11) or a local control unit (8) in said at least one group (24) is further configured to determine whether a predetermined condition is present or not.
  10. The system according to claim 8 or 9, characterised in that the remote control unit (11) or the local control unit (8) is further configured to selectively control the yaw movement of the nacelle (3) of said one wind turbine (1) according to the collective yaw angle command (26) or an individual yaw angle command (27) .
  11. The system according to one or more of claims 8 to 10, characterised in that the remote control unit (11) is further configured to update the operating data, e.g. the long term operating data, stored in said at least one database (12) , and to optionally redivide the plurality of wind turbines (1) in said at least one group (24) based on the updated operating data.
  12. The system according to one or more of claims 8 to 11, characterised in that the remote control unit (11) is configured to collect long term data (29) which long term data is measured data, and that the remote control unit (11) is configured to collect short term data (28) which short term data (28) is measured data.
PCT/CN2017/102049 2016-09-27 2017-09-18 Method and system of yaw control of wind turbines in a wind turbine farm WO2018059259A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102019116753A1 (en) * 2019-06-20 2020-12-24 Wobben Properties Gmbh Process for performing an energy yield forecast and wind farm

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107869420B (en) * 2016-09-27 2020-08-14 远景能源（江苏）有限公司 Method and system for controlling yaw of wind turbine farm
CN109026530B (en) * 2018-07-20 2019-10-11 国网冀北电力有限公司迁西县供电分公司 A kind of wind power generating set intelligence learning method
CN111120202B (en) * 2018-10-31 2021-07-20 北京金风科创风电设备有限公司 Yaw angle adjusting method, device, medium and equipment of wind generating set
CN112879220B (en) * 2021-03-16 2022-11-01 上海电气风电集团股份有限公司 Fan control method and system and readable storage medium

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030227172A1 (en) * 2002-06-07 2003-12-11 Erdman William L. Wind farm electrical system
CN101949363A (en) * 2010-09-21 2011-01-19 山东科技大学 Method for grouping wind generating sets by taking input wind speed and random fluctuation of wind direction of wind farm into consideration
US20140037447A1 (en) * 2012-08-06 2014-02-06 Sid Ahmed ATTIA Wind turbine yaw control
CN103717885A (en) * 2011-08-11 2014-04-09 维斯塔斯风力系统集团公司 Wind power plant and method of controlling wind turbine generator in a wind power plant
CN104018986A (en) * 2013-02-28 2014-09-03 国际商业机器公司 Draught fan controlling method and device
CN105041572A (en) * 2014-04-29 2015-11-11 通用电气公司 Systems and methods for optimizing operation of a wind farm
DK201670830A1 (en) * 2016-09-27 2017-10-02 Envision Energy (Jiangsu) Co Ltd Method and system of yaw control of wind turbines in a wind turbine farm

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DK177292B1 (en) * 2011-06-30 2012-10-08 Envision Energy Denmark Aps A wind turbine and an associated yaw control method
KR101418413B1 (en) * 2012-09-27 2014-07-09 삼성중공업 주식회사 Method for controlling wind farm
CN103150473A (en) * 2013-03-01 2013-06-12 风脉（武汉）可再生能源技术有限责任公司 Method and device for monitoring and diagnosing generating efficiency of wind turbine generator in real-time manner
US9453497B2 (en) * 2014-03-18 2016-09-27 General Electric Company Method for operating a wind farm
US9372201B2 (en) * 2014-03-31 2016-06-21 Alstom Renewable Technologies Yaw and pitch angles
CN105891546B (en) * 2016-01-26 2018-11-23 沈阳工业大学 The method of wind vane fault diagnosis in Wind turbines yaw system based on big data
CN105844361B (en) * 2016-03-29 2020-08-14 北京金风科创风电设备有限公司 Wind power prediction method, cable untwisting method and device for wind turbine generator
CN105909479B (en) * 2016-06-30 2018-11-27 华北电力科学研究院有限责任公司 Data acquisition device applied to the test of wind generating set yaw control performance

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030227172A1 (en) * 2002-06-07 2003-12-11 Erdman William L. Wind farm electrical system
CN101949363A (en) * 2010-09-21 2011-01-19 山东科技大学 Method for grouping wind generating sets by taking input wind speed and random fluctuation of wind direction of wind farm into consideration
CN103717885A (en) * 2011-08-11 2014-04-09 维斯塔斯风力系统集团公司 Wind power plant and method of controlling wind turbine generator in a wind power plant
US20140037447A1 (en) * 2012-08-06 2014-02-06 Sid Ahmed ATTIA Wind turbine yaw control
CN104018986A (en) * 2013-02-28 2014-09-03 国际商业机器公司 Draught fan controlling method and device
CN105041572A (en) * 2014-04-29 2015-11-11 通用电气公司 Systems and methods for optimizing operation of a wind farm
DK201670830A1 (en) * 2016-09-27 2017-10-02 Envision Energy (Jiangsu) Co Ltd Method and system of yaw control of wind turbines in a wind turbine farm

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102019116753A1 (en) * 2019-06-20 2020-12-24 Wobben Properties Gmbh Process for performing an energy yield forecast and wind farm
WO2020254514A1 (en) 2019-06-20 2020-12-24 Wobben Properties Gmbh Method for making an energy yield forecast, and wind farm

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