Operation control method and operation control device for wind power generation equipment

Abstract

To provide a wind power generation apparatus operation control method capable of suppressing a risk of damage to a power generator installed in a wind power generation apparatus.SOLUTION: A wind power generation apparatus operation control method is an operation control method of a wind power generation apparatus equipped with a power generator for generating power with wind. The operation control method includes: acquiring at least one of torque data on the power generator and wind state data when operating the wind power generation apparatus; calculating at least one of a torque index based on the torque data and a wind state index based on the wind state data; and suppressing output of the power generator if at least one of the torque index and the wind state index exceeds a threshold.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a method for controlling the operation of a wind power generation system and a control device for controlling the operation of a wind power generation system. [Background technology]

[0002] In wind power generation equipment, wind turbulence can increase the load on the blades due to wind speed fluctuations, raising concerns about the increased risk of equipment damage. For this reason, several operational control methods have been proposed that, when an indicator of wind turbulence around the blades exceeds a threshold, switch to a lower-output operating state than normal, reducing rotor speed and power output. While such output suppression operational control methods result in a loss of generated power, they reduce the load on the equipment and avoid downtime due to equipment failure, thus contributing to securing the total amount of generated power. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 5318454 [Patent Document 2] Patent No. 6421134 [Patent Document 3] Japanese Patent Publication No. 2021-88972 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Conventional operation control methods primarily aim to reduce the load acting on the blades, but the factors causing equipment damage within wind turbines are diverse and not limited to the blade load. For example, generators that generate electricity using the rotational force of blades often experience sudden fluctuations in torque during operation due to wind fluctuations (hereinafter referred to as torque sudden changes). These torque sudden changes are considered one factor that increases the risk of damage to the generator. Therefore, it is important to incorporate indicators based on torque sudden changes into the operation control of wind turbines.

[0005] However, conventional operating control systems primarily focus on the loads acting on the blades and do not consider suppressing the generator output based on sudden changes in torque.

[0006] The problem that this invention aims to solve is to propose an operation control method and operation control device for a wind power generation system that can reduce the risk of damage to the generator installed in the wind power generation system. [Means for solving the problem]

[0007] One embodiment of the operation control method for a wind power generation system is an operation control method for a wind power generation system equipped with a generator that generates electricity using wind power. This operation control method acquires at least one of the generator's torque data and wind condition data during the operation of the wind power generation system, calculates at least one of a torque index based on the torque data and a wind condition index based on the wind condition data, and suppresses the output of the generator if at least one of the torque index and the wind condition index exceeds a threshold. [Effects of the Invention]

[0008] According to this embodiment, it is possible to reduce the risk of damage to the generator installed in the wind power generation system. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the general configuration of a wind power generation system according to the first embodiment. [Figure 2] This is a block diagram showing the schematic configuration of the driving control device. [Figure 3] This is a flowchart illustrating the operation control method according to the first embodiment. [Figure 4] This graph shows an example of time-series data for torque change. [Figure 5] This figure shows the relationship between the number of torque sudden changes and the operating mode of the generator 7. [Figure 6]It is a flowchart for explaining an operation control method according to the second embodiment. [Figure 7] It is a diagram showing an example of the relationship between the wind condition and the number of torque mutations. [Figure 8] It is a graph showing an example of the time-series change of the wind speed. [Figure 9] It is a curve showing an example of the relationship between the wind speed and the torque of the generator in a wind power generation device. [Figure 10] It is a diagram showing an example of the relationship between the number of torque mutations and the wind speed. [Figure 11] It is a diagram showing an example of a data table indicating the correspondence between the turbulence intensity and the output command value of the generator. [Figure 12] It is a flowchart for explaining an operation control method according to the sixth embodiment. [Figure 13] It is a flowchart for explaining an operation control method according to the seventh embodiment. [Figure 14] It is a flowchart for explaining an operation control method according to the eighth embodiment. [Figure 15] It is a diagram showing an example of a data table indicating the correspondence between the wind direction and the threshold value of the index. [Figure 16] It is a flowchart for explaining an operation control method according to the ninth embodiment. [Figure 17] It is a flowchart for explaining an operation control method according to the tenth embodiment.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments do not limit the present invention.

[0011] (First Embodiment) FIG. 1 is a schematic diagram showing a schematic configuration of a wind power generation device according to the first embodiment. The wind power generation device 10 according to the present embodiment includes a nacelle 1 which is a housing, a tower 2 which is a support for the nacelle 1 from below, a plurality of blades 3, and a hub 4 which supports the plurality of blades 3.

[0012] The nacelle 1 houses a rotating shaft 5, a transmission mechanism 6, a generator 7, and an operation control device 9. One end of the rotating shaft 5 is fixed to the hub 4. The other end of the rotating shaft 5 is connected to the transmission mechanism 6.

[0013] The gear shifting mechanism 6 is connected to the generator 7 via an appropriate coupling mechanism or the like. In this embodiment, the base ends of the three blades 3 are fixed to the hub 4 at intervals of 120 degrees in the rotational direction.

[0014] During operation of the wind turbine 10, the multiple blades 3, which rotate together with the hub 4 and the rotating shaft 5, convert fluid energy obtained from wind into rotational energy. The rotational energy (driving force) of the rotating shaft 5 is then reduced or increased by the transmission mechanism 6 and transmitted to the generator 7. The generator 7 uses this transmitted rotational energy to generate electricity.

[0015] The wind condition measuring instrument 8 is installed on the outer perimeter of the nacelle 1. The wind condition measuring instrument 8 is an example of a wind speed sensor that functions as an anemometer capable of measuring wind direction or a wind direction indicator capable of measuring wind direction. The wind condition measuring instrument 8 measures wind condition data, such as the average wind speed and changes in wind speed, in the installation area where the wind power generation device 10 is installed, and outputs the measured wind condition data as a measurement result to the operation control device 9. Alternatively, the wind condition measuring instrument 8 may simply measure wind speed and wind direction and output these measurement results along with the time information of measurement to the operation control device 9. Furthermore, the installation area of ​​the wind condition measuring instrument 8 is not limited to the nacelle 1, but may be installed in the area surrounding the wind power generation equipment 10.

[0016] The operation control device 9 controls and measures the operating conditions of the wind turbine 10, including the rotational speed of the generator 7, the torque of the generator 7, the output power of the generator 7, and the pitch angle of the blades 3. The schematic configuration of the operation control device 9 will now be explained with reference to Figure 2.

[0017] Figure 2 is a block diagram showing the schematic configuration of the operation control device 9. The operation control device 9 shown in Figure 9 includes a data acquisition unit 90, a data processing unit 91, a control unit 92, and a storage unit 93. Each of these units will be described below.

[0018] The data acquisition unit 90 acquires various data, such as wind condition data from the wind condition measuring instrument 8 and operating data from the generator 7. The data acquisition unit 90 may acquire this data via a wired connection or wirelessly via a communication network.

[0019] The data processing unit 91 uses the data acquired by the data acquisition unit 90 to calculate an index representing the frequency of sudden torque changes. The data processing unit 91 also determines whether the calculated index exceeds a threshold.

[0020] The control unit 92 sets the generator 7 to either normal operation mode (first operation mode) or low-power operation mode (second operation mode) according to the determination result of the data processing unit 91. In normal operation mode, the generator 7 is set to the first torque value. On the other hand, in low-power operation mode, the generator 7 operates with reduced power output. Therefore, the second torque value of the generator 7 in low-power operation mode is set lower than the first torque value in normal operation mode.

[0021] The memory unit 93 stores various data, such as the threshold values ​​and wind condition data from the wind condition measuring instrument 8. If the data processing unit 91 is composed of a CPU (Central Processing Unit) that performs calculations based on a computer program, the memory unit 93 also stores that computer program.

[0022] The following describes the method of controlling the operation of the wind power generation system 10 using the operation control device 9.

[0023] Figure 3 is a flowchart illustrating the operation control method according to the first embodiment. In this flowchart, first, the data acquisition unit 90 acquires torque data showing the time-series change in the torque of the generator 7 (step S11). In step S11, the data acquisition unit 90 may extract torque data from operation data, or it may periodically acquire values ​​directly measured by a measuring instrument (not shown) installed on the generator 7 as torque data.

[0024] Next, the data processing unit 91 calculates an index representing the frequency of sudden torque changes based on the torque data acquired by the data acquisition unit 90 (step S12). For example, the data processing unit 91 calculates the number of sudden torque changes as the index. Now, with reference to Figure 4, the method for calculating the number of sudden torque changes in this embodiment will be explained.

[0025] Figure 4 is a graph showing an example of time-series data of torque change. In Figure 4, the horizontal axis represents time, while the vertical axis represents the torque change. In step S12, the data processing unit 91 first uses the torque data acquired by the data acquisition unit 90 to calculate the torque change at time t2, for example, by subtracting the torque value at the previous time t1 from the torque value at time t2.

[0026] Next, the data processing unit 91 counts the number of times the torque change exceeds a preset reference value S within an evaluation time range, which is a fixed period from time t1 to time tn, for example, 10 minutes. The data processing unit 91 then calculates the count value as the number of sudden torque changes. The evaluation time range is set to a value appropriate for operation control, such as 10 minutes.

[0027] Next, the data processing unit 91 determines whether the index calculated in step S12 exceeds a preset threshold (step S13). Specifically, the data processing unit 91 determines whether the number of sudden torque changes exceeds a threshold.

[0028] Next, the control unit 92 sets the operating mode of the generator 7 according to the determination result of the data processing unit 91. Now, referring to Figure 5, the relationship between the number of torque sudden changes and the operating mode of the generator 7 will be explained.

[0029] Figure 5 shows the relationship between the number of torque sudden changes and the operating mode of the generator 7. In Figure 5, the horizontal axis represents time, while the vertical axis represents the number of torque sudden changes.

[0030] As shown in Figure 5, if the number of torque sudden changes during the evaluation time interval is less than or equal to the threshold TH1, the control unit 92 sets the generator 7 to normal operation mode (step S14). In this case, the control unit 92 generates and outputs an output command value indicating the output power of the generator 7 corresponding to the normal operation mode.

[0031] On the other hand, if the number of torque sudden changes during the evaluation time period exceeds the threshold TH1, the control unit 92 sets the generator 7 to low-power operation mode (step S15). In this case, the control unit 92 generates and outputs an output command value indicating the output power of the generator 7 corresponding to the low-power operation mode. From this point onward, the transition to low-power operation mode will be described as output suppression.

[0032] In low-power operation mode, the generator output is reduced, resulting in a lower torque value for the generator 7 compared to normal operation mode. Consequently, torque fluctuations are also smaller than in normal operation mode. Therefore, the number of sudden torque changes is inevitably reduced.

[0033] According to the embodiment described above, if a sudden change in the torque of the generator 7 occurs and the index representing the frequency of such changes exceeds a threshold, the operation control device 9 suppresses the power output of the generator 7. This reduces the load acting on the generator 7. Therefore, it is possible to reduce the risk of damage to the generator 7.

[0034] (Second Embodiment) In the first embodiment described above, the operation control device 9 determines whether or not to suppress the output of the generator 7 using an index calculated from the torque value of the generator 7 included in the operation data. By applying this operation control method to the suppression of the output of the generator 7, it is expected that the frequency of sudden changes in torque will decrease.

[0035] However, when the generator 7 switches to low-power operation mode, the data acquisition unit 90 can no longer acquire data on the number of torque abrupt changes that would occur if the normal operation mode were continued. Therefore, it becomes difficult for the data processing unit 91 to determine when to release the output suppression that has been applied. The data processing unit 91 could, for example, release the low-power operation mode after a certain period of time, but a more appropriate method would be to make a determination using an index different from the index based on the operation data. Due to the characteristics of the wind power generation device 10, the frequency of torque abrupt changes is thought to depend heavily on the wind conditions. Therefore, in the second embodiment, the operation control device 9 newly incorporates an index calculated based on wind condition data measured by the wind condition measuring instrument 8 in order to determine whether or not output suppression of the generator 7 is necessary. The operation control method of the wind power generation device 10 by the operation control device 9 according to this embodiment will be described below.

[0036] Figure 6 is a flowchart illustrating the operation control method according to the second embodiment. In this flowchart, first, the data processing unit 91 analyzes the correlation between wind conditions and the number of sudden torque changes using past wind condition data and operation data of the wind power generation device 10 (step S21). Examples of indicators representing wind conditions include wind speed and turbulence intensity.

[0037] Figure 7 shows an example of the relationship between wind conditions and the number of torque sudden changes. In Figure 7, the horizontal axis represents turbulence intensity. Turbulence intensity is the value obtained by dividing the standard deviation of wind speed by the average wind speed. On the other hand, the vertical axis represents the number of torque sudden changes. As shown in Figure 7, there is a correlation between turbulence intensity and the number of torque sudden changes. Specifically, as the value of turbulence intensity increases, the number of torque sudden changes increases. The data processing unit 91, for example, obtains an approximate formula that shows the correlation between turbulence intensity and the number of torque sudden changes obtained from the distribution map shown in Figure 7. Note that the method for analyzing the correlation between turbulence intensity and the number of torque sudden changes is not limited to an approximate formula, and may also be performed by statistical processing, for example.

[0038] Next, the data processing unit 91 sets a threshold TH2 for turbulence intensity (step S22). Threshold TH2 corresponds to the threshold TH1 for the number of torque sudden changes described in the first embodiment. Therefore, the data processing unit 91 uses, for example, the approximation formula obtained in step S21 to determine the threshold TH2 for turbulence intensity corresponding to threshold TH1. Thus, in this embodiment, the correlation analysis between turbulence intensity and the number of torque sudden changes, and the setting of a threshold for turbulence intensity based on the analysis results are performed in advance. Note that in this embodiment, instead of turbulence intensity, the standard deviation of wind speed may be used as an index correlated with the number of torque sudden changes.

[0039] Next, the data acquisition unit 90 acquires the latest wind condition data during operation of the wind power generation device 10, which was measured by the wind condition measuring instrument 8 (step S23).

[0040] Next, the data processing unit 91 calculates an index based on the latest wind condition data measured by the wind condition measuring instrument 8 (step S24). In this embodiment, this index is the turbulence intensity.

[0041] Next, the data processing unit 91 determines whether the index calculated in step S24, i.e., the turbulence intensity, exceeds the threshold TH2 set in step S22 (step S25).

[0042] If the turbulence intensity is less than or equal to the threshold TH2, the control unit 92 sets the generator 7 to normal operation mode (step S26). In this case, the control unit 92 generates and outputs an output command value corresponding to the normal operation mode, similar to the first embodiment.

[0043] If the turbulence intensity exceeds the threshold TH2, the control unit 92 sets the generator 7 to low-power operation mode (step S27). In this case as well, the control unit 92 generates and outputs an output command value corresponding to the low-power operation mode, similar to the first embodiment.

[0044] According to the embodiment described above, the data processing unit 91 pre-sets a threshold TH2 of turbulence intensity corresponding to the number of sudden torque changes, and determines whether or not output suppression of the generator 7 is necessary based on the set threshold TH2. Turbulence intensity is a parameter that is not affected by the switching of the operating state (output suppression) of the wind power generation device 10. Therefore, by using this turbulence intensity, it becomes possible to more appropriately determine whether or not output suppression of the generator 7 is necessary.

[0045] (Third embodiment) In this embodiment, the index based on wind condition data differs from that in the second embodiment. Specifically, the difference between the maximum and minimum wind speeds within the evaluation time range is used. This difference indicates the range of wind speed fluctuations. This range of fluctuation is one of the indicators representing wind turbulence and, like turbulence intensity, correlates with the number of sudden torque changes.

[0046] Figure 8 is a graph showing an example of the time-series change in wind speed. In Figure 8, the horizontal axis represents time, while the vertical axis represents the wind speed measured by the wind condition measuring instrument 8. The index based on the wind condition data, i.e., the range of wind speed fluctuation, is the maximum wind speed V within the evaluation time range. max From the minimum wind speed V min This is the value after subtracting [a certain factor]. In this embodiment, the operation control device 9 controls the output of the generator 7 according to the flowchart described in the second embodiment. The steps of the flowchart will be described below.

[0047] In step S21 of this embodiment, the data processing unit 91 analyzes the correlation between the range of wind speed fluctuations and the number of sudden torque changes using past wind condition data and operating data of the wind power generation device 10. For example, the data processing unit 91 finds an approximate formula that shows this correlation.

[0048] Next, in step S22 of this embodiment, the data processing unit 91 determines the threshold TH3 of the wind speed fluctuation range corresponding to the threshold TH1 using, for example, the above approximation formula.

[0049] Next, in step S23 of this embodiment, the data acquisition unit 90 acquires the latest wind condition data measured by the wind condition measuring instrument 8.

[0050] Next, in step S24 of this embodiment, the data processing unit 91 calculates an index based on the latest wind condition data measured by the wind condition measuring instrument 8. In this embodiment, this index is the wind speed fluctuation range (V max -V min )

[0051] Next, in step S25 of this embodiment, the data processing unit 91 determines whether the wind speed fluctuation range calculated in step S24 exceeds the threshold TH3 set in step S22.

[0052] If the wind speed fluctuation range is less than or equal to the threshold TH3, in step S26 of this embodiment, the control unit 92 sets the generator 7 to normal operation mode. In this case, the control unit 92 generates and outputs an output command value corresponding to the normal operation mode, similar to the second embodiment.

[0053] Conversely, if the wind speed fluctuation range exceeds the threshold TH3, in step S27 of this embodiment, the control unit 92 sets the generator 7 to low-power operation mode. In this case as well, the control unit 92 generates and outputs an output command value corresponding to the low-power operation mode, similar to the second embodiment.

[0054] According to the present embodiment described above, the data processing unit 91 preset a threshold value TH3 of the fluctuation range of the wind speed corresponding to the number of torque mutations, and determines whether it is necessary to suppress the output of the generator 7 based on the set threshold value TH3. The fluctuation range of the wind speed is a parameter that is not affected by the switching (output suppression) of the operating state of the wind power generation device 10. Therefore, by using this fluctuation range, it is possible to more appropriately determine whether it is necessary to suppress the output of the generator 7 as in the second embodiment.

[0055] (Fourth Embodiment) One of the main factors causing torque mutations is the wind speed fluctuation due to wind turbulence. However, the occurrence frequency of torque mutations depends not only on an index representing wind turbulence such as the turbulence intensity but also on the wind speed level.

[0056] FIG. 9 is a curve showing an example of the relationship between the wind speed and the torque of the generator 7 in the wind power generation device 10. As shown in FIG. 9, the rated wind speed V of the wind power generation device 10 rat Hereinafter, the torque of the generator 7 increases as the wind speed increases. When the wind speed reaches the rated wind speed V rat range, the torque is controlled to be constant by the operation control device 9. The curve is a steeper curve in the wind speed range close to the rated wind speed V rat and the sensitivity of the generator torque to the wind speed is large in this wind speed range. Therefore, when the wind power generation device 10 is operating in the wind speed range close to the rated wind speed V rat the change amount of the torque of the generator 7 tends to be large with respect to the wind speed fluctuation.

[0057] FIG. 10 is a diagram showing an example of the relationship between the number of torque mutations and the wind speed. In FIG. 10, the horizontal axis represents the wind speed. On the other hand, the vertical axis represents the number of torque mutations. As shown in FIG. 10, the number of torque mutations tends to be large in the wind speed range close to the rated wind speed V rat

[0058] Therefore, in the present embodiment, the average wind speed V in the evaluation time width ave and the rated wind speed V rat ​The difference in wind speed is used as an indicator based on wind condition data, and output suppression is applied when this indicator falls within a preset range. In this embodiment as well, the operation control device 9 controls the output of the generator 7 according to the flowchart described in the second embodiment. The steps of the flowchart will be described below.

[0059] In step S21 of this embodiment, the data processing unit 91 uses past wind condition data and the operation data of the wind power generation device 10 to determine the average wind speed V ave and rated wind speed V rat We will analyze the correlation between the difference in wind speed and the number of sudden torque changes.

[0060] Next, in step S22 of this embodiment, the data processing unit 91 determines the range of the wind speed difference based on the threshold TH1. The range of the wind speed difference is, for example, the average wind speed V ave The rated wind speed is V rat With 0 being the median, the lower limit of the wind speed difference is V0-V rat From the upper limit of the wind speed difference V1-V rat It is set within the range up to V0-V. rat and upper limit V1-V rat This is determined appropriately according to the threshold TH1.

[0061] Next, in step S23 of this embodiment, the data acquisition unit 90 acquires the latest wind condition data measured by the wind condition measuring instrument 8.

[0062] Next, in step S24 of this embodiment, the data processing unit 91 calculates an index based on the latest wind condition data measured by the wind condition measuring instrument 8. In this embodiment, this index is the average wind speed V ave and rated wind speed V rat The difference in wind speed (V ave -V rat )

[0063] Next, in step S25 of this embodiment, the data processing unit 91 determines whether the wind speed difference calculated in step S24 is within the range set in step S22.

[0064] If the wind speed difference is outside the range, in step S26 of this embodiment, the control unit 92 sets the generator 7 to normal operation mode. In this case, the control unit 92 generates and outputs an output command value corresponding to the normal operation mode, similar to the second embodiment.

[0065] Conversely, if the wind speed difference is within the range, in step S27 of this embodiment, the control unit 92 sets the generator 7 to low-power operation mode. In this case as well, the control unit 92 generates and outputs an output command value corresponding to the low-power operation mode, similar to the second embodiment.

[0066] According to the embodiment described above, the data processing unit 91 calculates the average wind speed V corresponding to the number of torque sudden changes. ave and rated wind speed V rat A range of wind speed difference is set in advance, and the necessity of suppressing the output of the generator 7 is determined based on the set range. This wind speed difference is also a parameter that is not affected by the switching of the operating state (output suppression) of the wind power generation device 10. Therefore, by using this wind speed difference, it becomes possible to more appropriately determine whether or not to suppress the output of the generator 7, similar to the second embodiment.

[0067] (Fifth embodiment) When the operation control device 9 suppresses the output of the generator 7, the output command value in the low-output operation mode may be changed depending on the number of torque sudden changes and the value of an index based on wind condition data. For example, the greater the turbulence intensity, which is one of the indexes based on wind condition data, the more likely sudden changes in torque are to occur.

[0068] Therefore, in this embodiment, the operation control device 9 sets the output command value of the generator 7 based on the data table shown in Figure 11.

[0069] Figure 11 shows an example of a data table showing the correspondence between turbulence intensity and the output command value of the generator 7. The data table 100 shown in Figure 11 is stored in the memory unit 93. In the data table 100, the output command value of the generator 7 is set according to the range of turbulence intensity. Specifically, as the value of turbulence intensity increases, the output command value decreases in steps. Note that the output command value may be set continuously according to the value of turbulence intensity. That is, one output command value may be set for one value of turbulence intensity.

[0070] In this embodiment as well, the operation control device 9 controls the output of the generator 7 according to the flowchart described in the second embodiment. However, in step S27 of this embodiment, the control unit 92 sets the output command value of the generator 7 using the data table 100 stored in the memory unit 93. For example, if the turbulence intensity value calculated by the data processing unit 91 in step S24 corresponds to case 3, the control unit 92 selects the output command value W3 from the data table 100.

[0071] According to this embodiment, when the generator 7 operates in low-power mode, the output command value is not uniform but is set according to the turbulence intensity value. This prevents the output of the generator 7 from being suppressed more than necessary. Therefore, it becomes possible to optimize the output suppression of the generator 7.

[0072] In this embodiment, the output command value in the data table 100 may be set in association with the number of torque sudden changes instead of turbulence intensity. In this case, the data acquisition unit 90 acquires torque data instead of wind condition data. The data processing unit 91 also calculates the number of torque sudden changes described in the first embodiment as a torque index. If this torque index exceeds the threshold TH1, the control unit 92 switches the generator 7 to a low-output operation mode. In this case as well, the output of the generator 7 is not suppressed more than necessary, making it possible to optimize the output suppression of the generator 7.

[0073] (Sixth Embodiment) When using wind condition data-based indicators to determine whether or not output suppression of generator 7 is necessary, it is necessary to set an evaluation time interval when calculating statistics such as average wind speed, standard deviation, and turbulence intensity. A shorter evaluation time interval indicates a short-term trend, while a longer time interval indicates a long-term trend. To improve the responsiveness of output suppression when wind suddenly becomes turbulent, it is desirable to set a shorter evaluation time interval. However, the shorter the evaluation time interval, the larger the increase or decrease in the indicator, which increases the number of times the threshold is exceeded or fallen below it. As a result, it is expected that the frequency of switching the operating mode of generator 7 will increase.

[0074] Generally, wind turbulence often persists for a certain period, accompanied by fluctuations in wind speed. Therefore, even if output suppression is released because the short-term indicator momentarily falls below the threshold, it is expected that the indicator will exceed the threshold again the next moment. If the operating mode of the generator 7 is determined solely by the short-term indicator, there will be frequent switching between normal operation mode and low-output operation mode. As a result, there is a concern that sudden changes in the torque of the generator 7 may not be adequately avoided.

[0075] Therefore, in this embodiment, the operation control device 9 determines whether or not to suppress the output of the generator 7 by combining short-term and long-term indicators. The operation control method by the operation control device 9 according to this embodiment will be described below with reference to Figure 12.

[0076] Figure 12 is a flowchart illustrating the operation control method according to the sixth embodiment. In this flowchart, first, the data acquisition unit 90 acquires the latest wind condition data measured by the wind condition measuring instrument 8 (step S61).

[0077] Next, the data processing unit 91 calculates short-term and long-term indicators based on the latest wind condition data acquired by the data acquisition unit 90 (step S62). For example, the short-term indicator is the turbulence intensity calculated over a short evaluation time frame. On the other hand, the long-term indicator is the turbulence intensity calculated over a longer evaluation time frame than the short-term indicator.

[0078] Next, the data processing unit 91 determines whether the short-term indicator calculated in step S62 exceeds the threshold TH2a (step S63). The threshold TH2a is pre-set based on the correlation between the turbulence intensity and the number of torque sudden changes over past short evaluation time periods (see Figure 7) and stored in the memory unit 93.

[0079] If the short-term indicator exceeds the threshold TH2a, the control unit 92 sets the generator 7 to low-power operation mode (step S64). In this case, the control unit 92 generates and outputs an output command value corresponding to the low-power operation mode, similar to the first embodiment.

[0080] If the short-term indicator is less than or equal to the threshold TH2a, the data processing unit 91 determines whether the long-term indicator calculated in step S62 exceeds the threshold TH2b (step S65). The threshold TH2b is preset based on the correlation between the turbulence intensity and the number of torque sudden changes over past long evaluation time periods (see Figure 7) and is stored in the memory unit 93.

[0081] If the long-term indicator exceeds the threshold TH2b, the control unit 92 maintains the low-power operation mode.

[0082] If the long-term indicator is less than or equal to the threshold TH2b, the control unit 92 cancels the low-power operation mode and returns to the normal operation mode (step S66). Thus, in this embodiment, when the operation control device 9 determines whether or not to return from the low-power operation mode to the normal operation mode, it cancels the low-power operation mode (output suppression) only if the short-term indicator is less than or equal to the threshold TH2a and the long-term indicator is less than or equal to the threshold TH2b.

[0083] According to the embodiment described above, even if the short-term indicator momentarily falls below the threshold TH2a, the low-power operation mode is maintained as long as the long-term indicator exceeds the threshold TH2b. Therefore, unnecessary release of output suppression is avoided for the generator 7. This makes it possible to reduce the number of sudden torque changes in the generator 7 and suppress the risk of damage.

[0084] (Seventh Embodiment) As described in the sixth embodiment above, wind turbulence generally tends to persist for a certain period of time. Therefore, if the operating mode of the generator 7 is determined based solely on short-term indicators, there is a concern that frequent switching between the normal operating mode and the low-power operating mode may occur, making it difficult to adequately avoid sudden changes in the torque of the generator 7.

[0085] Therefore, in the seventh embodiment, different thresholds are set between the normal operation mode and the low-power operation mode. The operation control method by the operation control device 9 according to this embodiment will be described below with reference to Figure 13.

[0086] Figure 13 is a flowchart illustrating the operation control method according to the seventh embodiment. In this flowchart, first, the data acquisition unit 90 acquires the latest wind condition data measured by the wind condition measuring instrument 8 (step S71).

[0087] Next, the data processing unit 91 calculates an index based on the latest wind condition data acquired by the data acquisition unit 90 (step S72). For example, this index is the turbulence intensity over a preset evaluation time range.

[0088] Next, the data processing unit 91 determines whether the current operating state of the generator 7 is in normal operation mode or low-power operation mode (step S73).

[0089] If the current operating state of the generator 7 is in normal operation mode, the data processing unit 91 determines whether the index calculated in step S72 exceeds the threshold TH2c (step S74). The threshold TH2c is preset based on the correlation between turbulence intensity and the number of torque sudden changes in past normal operation modes (see Figure 7) and is stored in the memory unit 93.

[0090] If the current operating state of the generator 7 is in low-power operation mode, the data processing unit 91 determines whether the index calculated in step S72 exceeds the threshold TH2d (step S75). The threshold TH2d is preset based on the correlation between turbulence intensity and the number of torque sudden changes in past low-power operation modes (see Figure 7) and is stored in the memory unit 93. The threshold TH2d is smaller than the threshold TH2c.

[0091] If the indicator exceeds the threshold TH2c, the control unit 92 switches the generator 7 from normal operation mode to low-power operation mode (step S76). Conversely, if the indicator is less than or equal to the threshold TH2c, the control unit 92 maintains the operating state of the generator 7 in normal operation mode (step S77).

[0092] If the indicator exceeds the threshold TH2d, the control unit 92 maintains the operating state of the generator 7 in low-power operation mode (step S78). Conversely, if the indicator is less than or equal to the threshold TH2d, the control unit 92 switches the generator 7 from low-power operation mode to normal operation mode (step S79).

[0093] According to the embodiment described above, the threshold for the low-power operation mode is set lower than the threshold for the normal operation mode. As a result, once the generator 7 enters the low-power operation mode, it is easier to maintain that mode. Therefore, frequent switching between the low-power operation mode and the normal operation mode is avoided for the generator 7. This reduces the number of sudden changes in the torque of the generator 7 and suppresses the risk of damage.

[0094] In this embodiment, the threshold for each operating mode may be set based on the number of torque sudden changes instead of turbulence intensity. In this case, the data acquisition unit 90 acquires torque data. The data processing unit 91 calculates the number of torque sudden changes instead of turbulence intensity. Furthermore, if this number of torque sudden changes exceeds the threshold for the normal operating mode or the threshold for the low-power operating mode, the data processing unit 91 sets the generator 7 to the low-power operating mode. In this case as well, by setting the threshold for the low-power operating mode lower than the threshold for the normal operating mode, it is possible to avoid frequent switching of operating modes and reduce the number of torque sudden changes of the generator 7.

[0095] (Eighth embodiment) When the operation control device 9 uses an index based on wind condition data to suppress the output of the generator 7, a sudden change in torque does not necessarily occur when an index such as turbulence intensity exceeds a threshold. In some cases, a sudden change in torque may not occur even when the wind is turbulent. In this case, if the operation control device 9 suppresses the output of the generator 7 according to the index based on wind condition data, it will result in a loss of unnecessary generated power, which is undesirable.

[0096] Therefore, in this embodiment, the operation control device 9 determines whether or not to suppress the output of the generator 7 by combining a wind condition index based on wind condition data and a torque index based on torque data. The operation control method by the operation control device 9 according to this embodiment will be described below with reference to Figure 14.

[0097] Figure 14 is a flowchart illustrating the operation control method according to the eighth embodiment. In this flowchart, first, the data acquisition unit 90 acquires torque data (step S81). In step S81, the data acquisition unit 90 may extract torque data from operation data, or it may periodically acquire values ​​directly measured by a measuring instrument (not shown) installed on the generator 7 as torque data.

[0098] Following or in parallel with step S81, the data acquisition unit 90 acquires the latest wind condition data measured by the wind condition measuring instrument 8 (step S82).

[0099] Next, the data processing unit 91 calculates a torque index based on the torque data acquired by the data acquisition unit 90 (step S83). This torque index is, for example, the number of sudden torque changes described in the first embodiment.

[0100] Next, the data processing unit 91 calculates a wind condition index based on the wind condition data acquired by the data acquisition unit 90 (step S84). This wind condition index is, for example, the turbulence intensity described in the second embodiment.

[0101] Next, the data processing unit 91 determines whether the wind condition index exceeds the threshold TH21 (second threshold) (step S85). This threshold TH21 is, for example, a turbulence intensity value that is likely to cause a sudden change in the torque of the generator 7, and is stored in the memory unit 93.

[0102] If the wind condition index exceeds the threshold TH21, the data processing unit 91 determines whether the torque index exceeds the threshold TH11 (step S86). This threshold TH11 (first threshold) is, for example, the threshold for the number of sudden torque changes and is stored in the storage unit 93.

[0103] If the torque index exceeds the threshold TH11, the control unit 92 sets the generator 7 to low-power operation mode (step S87).

[0104] If the wind condition index is below the threshold TH22, or the torque index is below the threshold TH11, the control unit 92 sets the generator 7 to normal operation mode (step S88).

[0105] According to the embodiment described above, the operation control device 9 applies output suppression of the generator 7 only when the wind condition index exceeds the threshold TH21 and the torque index exceeds the threshold TH11. This makes it possible to avoid switching to a low-output operation mode even when no sudden change in torque has occurred.

[0106] (Ninth Embodiment) The wind turbine 10 often experiences different wind characteristics depending on the wind direction, due to factors such as the surrounding topography of the installation area. Therefore, when the operation control device 9 determines whether or not output suppression of the generator 7 is necessary, it is preferable to set different threshold values ​​for indicators depending on the wind direction. For example, if past data reveals that the reduction effect against sudden changes in torque is insufficient at a particular wind direction, the threshold value for the indicator at that wind direction is set lower. This makes it easier to apply output suppression of the generator 7.

[0107] Therefore, in this embodiment, the operation control device 9 uses the threshold value THα registered in the data table shown in Figure 15 to determine whether or not it is necessary to suppress the output of the generator 7.

[0108] Figure 15 shows an example of a data table showing the correspondence between wind direction and an index threshold. The data table 200 shown in Figure 15 is stored in the storage unit 93. In the data table 200, the turbulence intensity threshold THα is set for each wind direction. In the data table 200, thresholds THα are set for eight wind directions, but the number of wind directions is not limited to eight, and may be, for example, four or sixteen. Now, with reference to Figure 16, the operation control method by the operation control device 9 according to this embodiment will be described.

[0109] Figure 16 is a flowchart illustrating the operation control method according to the ninth embodiment. In this flowchart, first, the data acquisition unit 90 acquires the latest wind condition data measured by the wind condition measuring instrument 8 (step S91).

[0110] Next, the data processing unit 91 calculates an index based on the latest wind condition data acquired by the data acquisition unit 90 (step S92). For example, this index is the turbulence intensity over a preset evaluation time range.

[0111] Next, the data processing unit 91 uses the data table 200 stored in the storage unit 93 to determine whether the index exceeds the threshold THα (step S93). In step S93, the data processing unit 91 identifies the wind direction from the wind condition data. Subsequently, the data processing unit 91 reads the threshold THα corresponding to the identified wind direction from the data table 200. If the identified wind direction is not registered in the data table 200, the data processing unit 91 reads the threshold THα corresponding to the closest wind direction. Subsequently, the data processing unit 91 compares the index (turbulence intensity) calculated in step S92 with the read threshold THα.

[0112] If the indicator is below the threshold THα, the control unit 92 sets the generator 7 to normal operation mode (step S94).

[0113] If the indicator exceeds the threshold THα, the control unit 92 sets the generator 7 to low-power operation mode (step S95).

[0114] According to this embodiment, the threshold values ​​of the indicators based on wind condition data are optimized for each wind direction. Therefore, it is possible to reduce sudden changes in torque regardless of wind direction and suppress the risk of damage to the generator 7.

[0115] In this embodiment, the data table 200 may have threshold values ​​for the number of torque sudden changes set according to wind direction. In this case, the data acquisition unit 90 acquires torque data. The data processing unit 91 calculates the number of torque sudden changes. Subsequently, the data processing unit 91 selects a threshold value from the data table 200 to compare with the number of torque sudden changes. Even if the threshold values ​​for the index based on torque data are optimized according to wind direction, it is possible to reduce torque sudden changes regardless of wind direction and suppress the risk of damage to the generator 7.

[0116] (Tenth embodiment) In the operation control methods described in the second to ninth embodiments, the index based on wind condition data is calculated based on wind condition data measured by a wind condition measuring instrument 8 installed on the wind power generation device 10. Since wind condition data is a value at a specific spatial location, the amount of information is limited. In contrast, in wind condition analysis, which determines the wind flow around the installation area of ​​the wind power generation device 10 by numerical simulation, a spatial wind speed distribution around the blades 3 can be obtained.

[0117] Therefore, in this embodiment, by acquiring wind condition analysis data showing the results of this wind condition analysis, it becomes possible to set more detailed indicators. For example, it becomes possible to provide wind condition indicators (such as turbulence intensity) at multiple locations. Now, with reference to Figure 17, the operation control method by the operation control device 9 according to this embodiment will be described.

[0118] Figure 17 is a flowchart illustrating the operation control method according to the tenth embodiment. In this flowchart, first, the data processing unit 91 analyzes the correlation between wind conditions and the number of sudden torque changes using past wind condition data and operation data of the wind power generation device 10, similar to step S21 of the second embodiment (step S101).

[0119] Next, the data processing unit 91 sets a threshold TH2 for turbulence intensity, similar to step S22 of the second embodiment (step S102). The threshold TH2 corresponds to the threshold TH1 for the number of torque sudden changes described in the first embodiment.

[0120] Next, the data acquisition unit 90 acquires wind condition analysis data (step S103). This wind condition analysis data shows wind condition indicators, such as turbulence intensity, at multiple locations within the installation area of ​​the wind power generation device 10. This wind condition analysis data is created in advance by, for example, a wind condition analysis device (not shown), and the data acquisition unit 90 acquires it from this wind condition analysis device. The wind condition analysis data may also be stored in advance in the storage unit 93. In step S103, the data acquisition unit 90 may also acquire weather forecast data for the installation area of ​​the wind power generation device 10. The weather forecast data includes, for example, weather analysis models such as MSM (Meso Scale Model) and LFM (Local Forecast Model) provided by the Japan Meteorological Agency.

[0121] Next, the data processing unit 91 calculates a wind condition index using the wind condition analysis data (step S104). In step S104, the data processing unit 91 determines the maximum and average values ​​of turbulence intensity at multiple locations shown in the wind condition analysis data, and calculates the obtained values ​​as a wind condition index.

[0122] Next, the data processing unit 91 determines whether the index calculated in step S104, i.e., the turbulence intensity, exceeds the threshold TH2 set in step S102 (step S105).

[0123] If the turbulence intensity is less than or equal to the threshold TH2, the control unit 92 sets the generator 7 to normal operation mode (step S106). On the other hand, if the turbulence intensity exceeds the threshold TH2, the control unit 92 sets the generator 7 to low-power operation mode (step S107).

[0124] According to the embodiment described above, wind condition analysis data is used in the calculation of wind condition indicators. The wind condition analysis data shows wind condition indicators at multiple locations within the installation area of ​​the wind power generation device 10. By controlling the operation of the generator 7 based on wind condition indicators at many locations in this way, it is possible to improve the reduction effect against sudden changes in torque.

[0125] (11th embodiment) In the operation control methods of the operation control device 9 according to each embodiment described above, the output of the generator 7 is suppressed in order to reduce sudden changes in torque. This output suppression results in a loss of generated power. While it is important to reduce the risk of damage to the generator 7, it is equally important to keep the loss of generated power at an acceptable level.

[0126] Therefore, in this embodiment, when the application period of the low-power operation mode ends, the data processing unit 91 calculates the amount of power loss L associated with the low-power operation mode based on the following equations (1) and (2). P1 = P2 × Cv1 / Cv2 (1) L = P1 - P2 (2)

[0127] In equation (1) above, P2 is the actual amount of power generated by the generator 7 during the period in which the low-power operation mode is applied. Cv1 is the output command value in the normal operation mode. Cv2 is the output command value in the low-power operation mode. P1 is the amount of power generated in the normal operation mode, calculated from the amount of power generated in the low-power operation mode. The loss L corresponds to the difference between P1 and P2.

[0128] If the loss amount L is outside a preset tolerance range, the data processing unit 91 changes the output command value for the low-power operation mode or the threshold value of the indicator used to determine whether output suppression is necessary, so that the loss amount L falls within the tolerance range. For example, the data processing unit 91 increases the output command value for the low-power operation mode or raises the threshold value of the indicator. This tolerance range is the range in which the loss of generated power can be kept to the minimum necessary while suppressing sudden changes in the torque of the generator 7.

[0129] According to the embodiment described above, the operation control device 9 incorporates the amount of power loss of the generator 7 as an evaluation index and controls its operation. This makes it possible to control the operation of the generator 7 in a more practical manner.

[0130] (12th embodiment) In a wind farm where multiple wind turbines 10 are installed, one method is to individually set the torque index threshold TH1 and the wind condition index threshold TH2 for each wind turbine. In contrast, in this embodiment, a single threshold is set for all wind turbines in the wind farm. For example, the smallest value among the thresholds set based on the data of each individual wind turbine is applied to all wind turbines 10 in the wind farm. By setting the thresholds in this way, a more conservative threshold setting is achieved, making it possible to reduce the risk of damage.

[0131] Although several embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel system described herein can be implemented in a variety of other forms. Furthermore, various omissions, substitutions, and modifications can be made to the forms of the system described herein without departing from the spirit of the invention. The appended claims and equivalents are intended to include such forms and modifications that are included in the scope and spirit of the invention. [Explanation of Symbols]

[0132] 1: Nasser 2: Tower 3: Blade 4: Hub 5: Rotation axis 6: Transmission mechanism 7: Generator 8: Wind Condition Measuring Instrument 9: Driving control device 10: Wind power generation equipment 90: Data acquisition unit 91: Data Processing Unit 92: Control Unit 93: Storage part

Claims

1. A method for controlling the operation of a wind power generation system equipped with a generator that generates electricity using wind power, Torque data of the generator is acquired, The process involves calculating a torque index based on the torque data, calculating the amount of change in torque using the torque data, and calculating the number of sudden torque changes, which indicates the number of times the amount of change exceeds a preset reference value within the evaluation time range, as the torque index. If the torque index exceeds a threshold, the output of the generator is suppressed. A method for controlling the operation of a wind power generation system.

2. The method for controlling the operation of a wind power generation system according to claim 1, wherein the output of the generator is suppressed when the wind condition index, based on wind condition data during the operation of the wind power generation system, exceeds a threshold set based on the torque of the generator.

3. The method for controlling the operation of a wind power generation apparatus according to claim 2, wherein the standard deviation of wind speed or turbulence intensity is calculated as the wind condition index.

4. The method for controlling the operation of a wind power generation apparatus according to claim 2, wherein the difference between the maximum and minimum values ​​of wind speed during the evaluation time interval is calculated as the wind condition index.

5. The method for controlling the operation of a wind power generation device according to claim 2, wherein the difference between the average wind speed over an evaluation time period and the rated wind speed of the wind power generation device is calculated as the wind condition index.

6. A method for controlling the operation of a wind power generation apparatus according to claim 1, wherein the output of the generator is suppressed based on an output command value that is set in advance according to the torque index.

7. A method for controlling the operation of a wind power generation system according to claim 2, wherein a determination is made whether or not to suppress the output of the generator using a plurality of wind condition indicators calculated over a plurality of different evaluation time intervals.

8. The method for controlling the operation of a wind power generation apparatus according to claim 1, wherein different thresholds are set for the torque index in the first operating mode and the second operating mode, which have different torque values ​​for the generator.

9. A first threshold value for the torque index is set, and a second threshold value for the wind condition index is set. A method for controlling the operation of a wind power generation apparatus according to claim 2, wherein the output is suppressed when the torque index exceeds the first threshold and the wind condition index exceeds the second threshold.

10. The method for controlling the operation of a wind power generation apparatus according to claim 2, wherein a threshold value for the torque index or a threshold value for the wind condition index is set for each wind direction.

11. Wind condition analysis data is obtained by analyzing the wind conditions in the installation area of ​​the wind power generation device. A method for controlling the operation of a wind power generation apparatus according to claim 2, wherein the wind condition index is calculated based on the wind condition analysis data.

12. The amount of power loss when the output is suppressed is calculated, The method for controlling the operation of a wind power generation apparatus according to claim 1, wherein the threshold value or the output command value for suppressing the output is changed so that the amount of loss falls within a preset allowable range.

13. The method for controlling the operation of a wind turbine according to claim 1, wherein a single threshold value is set for all of the multiple wind turbines.

14. An operation control device for a wind power generation system equipped with a generator that generates electricity using wind power, A data acquisition unit that acquires torque data for the generator, A data processing unit for calculating a torque index based on the torque data, comprising: a data processing unit that calculates the amount of change in torque using the torque data, and calculates the number of times the amount of change exceeds a preset reference value within an evaluation time range as the torque index; If the torque index exceeds a threshold, a control unit suppresses the output of the generator, An operation control device for a wind power generation system equipped with the following features.

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