JP6906354B2 - Wind turbine generator fatigue damage calculation device, wind power generation system, and wind turbine generator fatigue damage calculation method - Google Patents

Description

An embodiment of the present invention relates to a fatigue damage amount calculation device for a wind turbine generator, a wind power generation system, and a fatigue damage amount calculation method for a wind turbine generator.

Power generation companies that operate wind turbine generators are required to reduce operating costs. In the operating cost of a wind turbine generator, it is necessary to consider inspection, repair, and shutdown due to failure. It is known that this operating cost increases sharply with the passage of time after the introduction of the wind turbine generator. That is, since the wind turbine generator is continuously affected by the constantly fluctuating wind, the load repeatedly applied to each part of the wind turbine generator body causes fatigue damage and wear damage, resulting in an increase in operating cost.

Therefore, at the design stage of the wind turbine generator, the strength is evaluated by fully considering the influence of such wind. Specifically, wind condition information will be collected in advance at the planned installation location of the wind turbine generator, and a wind turbine generator with sufficient strength against expected average wind speed and fluctuations in wind speed will be designed. For example, in the IEC wind turbine standard, the wind intensity has three levels of reference wind speed, which is an index showing wind speed, while there are three levels of turbulent flow intensity, which is an index showing wind fluctuation, and nine levels are combined. It is classified into. Therefore, the wind turbine generator is designed assuming the wind conditions at the planned installation location and the actual operation.

For example, a structure such as a tower or a nacelle constituting a wind turbine generator can reduce stress caused by wind and secure sufficient fatigue strength by appropriately designing the structure. That is, since towers and nacelles are unlikely to be destroyed by fatigue over time, for example, while the wind turbine generator is operating or stopped, the stress caused by the influence of wind is measured and the state of fatigue damage is calculated. There is almost no need to do it.

On the other hand, the blade of a wind turbine generator is a structure in which fatigue damage is likely to occur due to long-term operation or fluctuation of actual wind speed because a large margin for fatigue strength cannot be obtained. Therefore, the blade needs to accurately predict the aging fatigue damage situation.

The gears and bearings built into the wind turbine generator are likely to be damaged by wear due to the fluctuating load caused by the wind. Can be detected. In other words, if the amount of damage to the blades can be estimated from the actual operation of the wind turbine generator and fluctuations in wind speed, the power generation company can rationalize the operation control, inspection and repair of the wind turbine generator and reduce the operating cost. ..

Here, the current fatigue damage rate or degree of deterioration is calculated from the stress acting on each part of the wind turbine calculated based on the output of the anemometer or load sensor attached to the nacelle, etc., and these are further determined by a predetermined fatigue deterioration schedule. The first and second techniques for controlling the operation of the wind turbine while contrasting with the table have been proposed. According to these technologies, fatigue deterioration of wind turbine blades due to fluctuating load can be prevented by changing the control of the wind turbine depending on whether the current fatigue damage rate has a margin or not with respect to the fatigue deterioration schedule. You can drive the windmill in an ideal environment.

Further, in a wind power generation system having a plurality of wind power generation devices, the wind power generation devices are grouped based on the degree of deterioration, and each wind power generation device included in the highly deteriorated wind power generation device group is preferentially controlled for power reduction. The technology is known. In other words, this technology can extend the life of a wind farm (large-scale centralized wind farm) while controlling the output of active power according to the requirements of the power system.

Japanese Patent No. 4241644 Japanese Patent No. 4939508 Japanese Patent No. 5167365

By the way, in order to optimize the operation of wind power generation equipment and wind farms by applying the above-mentioned first to third technologies, it is premised that the current fatigue damage rate of wind power generation equipment is calculated accurately. Become. Specifically, in the first technique, a load waveform representing a load applied to each part is obtained from the wind speed and the wind direction obtained from an acceleration sensor attached to the nacelle, and the stress is calculated from the load waveform. Further, in the first technique, it is also considered to calculate the stress in the same manner based on the information from various sensors instead of the anemometer, or to directly measure the stress. On the other hand, in the second technique, the calculation of the load is considered in more detail, and the load time series data is created from the information obtained by the wind power meter and the information on the operation control and the operation status, and the stress time is generated from the data. Series data and maximum principal stress time series data are calculated.

In the method of calculating the fatigue damage rate using these first and second techniques, the load waveform is obtained from the information actually measured by the sensor, for example, the wind speed and the wind direction, and the stress waveform required for the evaluation of fatigue damage is calculated. It can be said that this method conforms to the ICE wind turbine standard for calculating the stress waveform of each part with respect to the wind condition assumed as a design condition.

However, since this calculation method is performed using data of wind speed and operating conditions that constantly change in a short time, a very high-speed calculation is required using a high-performance sensor and a computer. Further, when it is difficult to perform real-time calculation following changes in wind speed, a storage device for temporarily storing data is also required. Therefore, due to the necessity of introducing these devices, it is difficult for the above method to reduce the operating cost of the wind turbine generator.

Further, in the method of calculating the fatigue damage rate using the first and second techniques, the calculation process for calculating the load and stress is performed in almost the same manner as the calculation at the design stage. During the operation of the wind power generation equipment, various loads and stresses may be generated in each part of the wind power generation equipment due to the combination of special wind conditions such as various operations, equipment abnormalities, gusts and typhoons. Is difficult to predict accurately. In detail, there is a difference between the load and stress that the designer assumed (calculated) to act on each part of the wind power generation device at the design stage and the load and stress actually generated on each part of the wind power generation device. If so, it is difficult for generators to find these differences.

Further, the third technique estimates the degree of deterioration (fatigue) of the wind power generator from the output of the generator, and a simpler method is adopted as compared with the first and second techniques. However, the accuracy of the evaluation when calculating the degree of deterioration of the wind power generator from the generator output depends on the amount of correlation data between both the generator output and the degree of deterioration, so a sufficient evaluation result is obtained from the viewpoint of the power generation company. It may not have been obtained.

As described above, the current technology may not be able to evaluate the actual fatigue damage of the wind turbine generator. On the other hand, improving the prediction accuracy of fatigue damage of a wind turbine generator requires, for example, analysis of a huge amount of data obtained by high-speed sampling of a large number of sensors, and in this case, an increase in operating cost is resulted. I will invite you.

Therefore, the problem to be solved by the present invention is the fatigue damage amount of the wind turbine generator, the wind power generation system, and the fatigue damage amount of the wind turbine generator, which can easily improve the analysis accuracy of the fatigue life of the wind turbine generator. It is to provide a calculation method.

The fatigue damage amount calculation device of the wind turbine generator according to the embodiment includes a wind condition information acquisition unit, a fatigue damage amount calculation unit, a strain information acquisition unit, first and second load information calculation units, and a fatigue damage amount correction unit. It also has a fatigue damage integration unit. The wind condition information acquisition unit acquires the average wind speed and the change in the wind speed measured at the installation location of the wind turbine generator during a certain period of time. The fatigue damage amount calculation unit calculates the fatigue damage amount of the blade of the wind turbine generator based on the acquired wind condition information. The strain information acquisition unit acquires information representing the strain at a predetermined portion of the wind turbine generator measured during the fixed period. The first load information calculation unit calculates the first load information representing the average load applied to the blade and the change in the load during the fixed period based on the acquired information representing the strain. The second load information calculation unit calculates the second load information representing the average load applied to the blade and the change in the load during the fixed period based on the acquired wind condition information. The fatigue damage amount correction unit corrects the calculated fatigue damage amount based on the calculated first and second load information, respectively. The fatigue damage amount integrating unit integrates a plurality of fatigue damage amounts corrected by the fatigue damage amount correcting unit in units of the fixed period.

According to the present invention, there is provided a fatigue damage amount calculation device for a wind turbine generator, a wind power generation system, and a fatigue damage amount calculation method for a wind turbine generator, which can easily improve the analysis accuracy of the fatigue life of the wind turbine generator. be able to.

The figure which shows schematic the structure of the wind power generation system which concerns on 1st Embodiment. The flowchart which shows the fatigue damage amount calculation method of the comparative example. The figure which shows the change of the wind speed for 10 minutes measured by the wind condition measuring instrument of the wind turbine generator in the wind power generation system of FIG. The figure which shows the change of the load applied to the blade of the wind turbine generator in 10 minutes of FIG. 3A. The figure which shows the moment acting on the blade of the wind turbine generator in 10 minutes of FIG. 3A. It is a figure which shows the result of having cycle-counted the change of the load for 10 minutes of FIG. 3B by the rainflow method, and arranged by the histogram. The figure which shows the result which made the distribution of the histogram of FIG. 4A into a function and made it into a probability density. The figure which shows the analysis example of the shape parameter of the load fluctuation distribution based on the average wind speed. The figure which shows the analysis example of the shape parameter of the load fluctuation distribution based on the turbulent flow intensity. The figure which illustrated the fatigue life diagram of the target part of the fatigue evaluation. A matrix showing the relationship between average wind speed and turbulent flow intensity. The figure which shows the relationship between the turbulent flow intensity and the average wind speed, and the amount of fatigue damage. The figure which shows the relationship between the turbulent flow intensity and the amount of fatigue damage. A matrix showing the relationship between the average wind speed during operation of a wind turbine generator and the change in wind speed. A matrix showing the relationship between the average wind speed while the wind turbine generator is stopped and the change in wind speed. The figure which shows the relationship between the average wind speed during operation of a wind turbine generator, and the amount of fatigue damage. The figure which shows the relationship between the average wind speed and a load change during operation of a wind turbine generator. The figure which shows the relationship between the load change to a blade based on the information which expresses a strain or the wind condition information, and the average wind speed. The flowchart which shows the fatigue damage amount calculation method by the fatigue damage amount calculation apparatus of the wind turbine generator of FIG. The figure which shows schematic the structure of the wind power generation system which concerns on 2nd Embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
<First Embodiment>
As shown in FIG. 1, the wind power generation system 10 according to the present embodiment includes a wind turbine generator (wind turbine generator) 20 and a fatigue damage amount calculation device 30 for the wind turbine generator. The wind turbine generator 20 includes a nacelle 15 as a housing, a tower 14 that supports the nacelle 15 from below, a plurality of blades (wind turbine blades) 12, and a boss that supports the plurality of blades 12 via a hub. It mainly has 19 and.

The nacelle 15 incorporates a rotating shaft 17, a transmission mechanism 16, and a generator main body 18. One end of the rotating shaft 17 is fixed to the boss 19, and the other end of the rotating shaft 17 is connected to the speed change mechanism 16. The transmission mechanism 16 is connected to the generator main body 18 via an appropriate coupling mechanism or the like. For example, in each of the three blades 12, the base end portions thereof are fixed around the axis of the boss 19 (rotating shaft 17) at an interval of 120 degrees (deg).

Here, during the operation of the wind turbine generator 20 (during power generation), the directions of the pressure surface (positive pressure surface) and the negative pressure surface of each blade body are adjusted so that each blade 12 rotates in response to the wind force. .. While the operation of the wind turbine generator 20 is stopped (during non-power generation), the directions of the pressure surface and the negative pressure surface of each blade body are adjusted so that the blades 12 do not rotate, for example, even if they receive wind power. The plurality of blades 12, the boss 19 and the rotating shaft 17 are rotatably supported with respect to the nacelle 15.

That is, during the operation of the wind turbine generator 20, the plurality of blades 12 that rotate integrally with the boss 19 and the rotating shaft 17 convert the fluid energy obtained from the wind power into rotational energy. Further, the rotational energy (driving force) of the rotating shaft 17 is decelerated or accelerated by the transmission mechanism 16 and transmitted to the generator main body 18. The generator main body 18 uses the transmitted rotational energy to generate electricity.

On the other hand, the nacelle 15 is provided with a wind condition measuring instrument (wind condition sensor) 23 having functions such as an anemometer and an anemometer. The wind condition measuring instrument 23 capable of measuring the wind direction and the wind speed measures the wind condition information representing, for example, the average wind speed and the change in the wind speed at the installation location of the wind turbine generator 20, and this wind condition information (measured). (Measurement result) is output. The wind condition measuring instrument 23 may simply measure the wind speed and the wind direction, and output the measurement result together with the measured time information. On the other hand, the tower 14 is provided with strain gauges 21 and 22 and an entrance / exit 24 for workers to enter and exit.

The strain gauges 21 and 22 are attached to the body portion (main body portion) of the tower 14, and measure the strain of the tower 14, for example, in the axial direction, respectively. The strain gauges 21 and 22 may be attached so as to measure the strain of the tower 14, for example, in the radial direction. Further, as shown in FIG. 1, the strain gauge 21 and the strain gauge 22 are attached to the tower 14 at different positions, for example, at different heights. Based on the measurement results of the strain gauges 21 and 22, it is possible to calculate the load applied to the tower 14 and the blade 12 by wind power and the change in the load. Further, it is possible to calculate the bending moment applied to the tower 14 based on the measurement results of the strain gauges 21 and 22, the dimensional values of each part of the tower 14, and the mounting positions of the strain gauges 21 and 22. ..

Here, the direction in which the bending moment is applied to the tower 14 is affected by the mounting direction and position of the nacelle 15. However, for example, two strain gauges are placed at the same height position in the height direction of the tower 14 and at a position where the tower 14 is 360 degrees (deg) and 90 degrees (deg) offset from each other in the orbital angle direction. By installing each of the above and measuring the strain in the axial direction of the tower 14, it is possible to determine the direction in which the bending stress is maximized in the tower 14. Further, in addition to these two strain gauges whose mounting positions are shifted by 90 degrees, as described above, strain gauges whose mounting heights are shifted may be further added.

The strain gauge is preferably attached (attached) to the lower floors of the tower 14 where the bending moment increases according to the force applied to the blade 12, but the rigidity of the tower 14 does not change according to the circumferential direction of the tower 14. As shown in FIG. 1, it is better to avoid the height position where the doorway 24 is provided.

By the way, FIG. 2 is a flowchart showing a fatigue life analysis process in the first technique described above as a comparative example. In this comparative example, a method of calculating the deterioration degree of the wind turbine and controlling the wind turbine by using the information comparing the current deterioration degree and the deterioration degree schedule over a long period of time is disclosed. In this comparative example, as a method of calculating the current degree of deterioration, the load waveform applied to the wind turbine is calculated using the information acquired from a sensor such as an anemometer (S21) (S22), and the coordinates are based on this load waveform. A specific coefficient is calculated by performing conversion (S23), and the stress waveform generated in the wind turbine is obtained from this calculation result (S24). Further, the stress frequency is calculated from this stress waveform using the rainflow count method (S25), and the fatigue damage rate for each repeated stress is obtained from the calculated stress frequency from the linear cumulative damage rule (S26). It can be said that this series of fatigue damage amount calculation methods is a known technique based on the general fatigue design method in the wind turbine design standard of the IEC (International Electrotechnical Commission).

FIG. 3A shows a change in the wind speed for 10 minutes measured by the wind condition measuring instrument 23 as a measurement example for a certain period. Further, FIG. 3B shows the change in the load applied to the blade 12 in the above 10 minutes, and FIG. 3C shows the change in the moment acting on the blade 12 in the above 10 minutes. In this way, the wind speed changes constantly, and the load and moment acting on the blade 12 also change accordingly. From such fluctuations in load and moment, it is possible to evaluate fatigue damage by calculating the stress fluctuation of the target portion for fatigue evaluation and the number of such fluctuations (number of repetitions). However, high-performance computers and sensors are required for fatigue damage evaluation, which calculates and accumulates such fast-changing events one by one.

In addition, when calculating the repetitive stress applied to the blades of a wind turbine from changes in wind speed, the effect of the so-called tower shadow effect (a phenomenon in which the rotation of the blades slows down when the rotating blades pass in front of the tower), that is, The calculation result does not take into account the stress change that accompanies the rotation of the blade. If a sensor such as a strain gauge is attached to the root part (root part) of each blade, the influence of the tower shadow effect described above will be added to the calculation result of the repetitive stress, but the number of sensors used will increase. The number will increase, and the calculation load will increase accordingly. Further, in this case, since complicated calculation is required, it is difficult for the power generation company to judge the validity of the fatigue damage evaluation.

Therefore, the fatigue damage amount calculation device 30 of the wind turbine generator according to the present embodiment does not need to analyze a huge amount of data obtained by high-speed sampling, for example, and the fatigue of the wind turbine generator is appropriate from the viewpoint of the power generation company. It can evaluate damage. The fatigue damage amount calculation device 30 of the present embodiment does not calculate and accumulate the fatigue damage rate one by one according to the change in wind speed, but obtains the fatigue damage rate at regular intervals (predetermined period), and finally. Accumulate the fatigue damage rate at regular intervals.

Specifically, as shown in FIG. 1, the fatigue damage amount calculation device 30 of the wind turbine generator of the present embodiment includes a wind condition information acquisition unit 31, a fatigue damage amount calculation unit 32, a strain information acquisition unit 33, and a first. The load information calculation unit 34, the second load information calculation unit 35, the fatigue damage amount correction unit 36, the fatigue damage amount integration unit 37, the fatigue damage amount output unit 38, and the correlation storage unit 39 are provided. Each component (component shown by a functional block in FIG. 1) including the wind condition information acquisition unit 31 and the fatigue damage amount calculation unit 32 is made of hardware configured by combining various electronic components. It may be realized, or it may be realized by software obtained by executing a predetermined program.

The wind condition information acquisition unit 31 acquires wind condition information representing the average (average wind speed) of the wind speed and the change in the wind speed (change width of the wind speed) measured during a certain period at the installation location of the wind turbine generator 20. That is, the wind condition information acquisition unit 31 may be configured to acquire the above-mentioned wind condition information output from, for example, the wind condition measuring instrument 23 provided in the nacelle 15 of the wind turbine generator 20, or the wind condition measurement. For example, the wind speed, the wind direction, and the measurement time measured by the instrument 23 may be received from the wind condition measuring instrument 23, and the wind condition information may be calculated based on the received information to acquire the wind condition information. ..

Here, the above-mentioned wind condition information divides the information representing the difference between the maximum wind speed and the minimum wind speed during a certain period and the standard deviation of the change in the wind speed during a certain period (standard deviation of the fluctuating wind speed) by the average of the wind speeds. It is a concept that includes information indicating the turbulent flow intensity. The wind condition information acquisition unit 31 of the present embodiment acquires, for example, the average wind speed for 10 minutes and the turbulent flow intensity as representative values (index values).

On the other hand, the fatigue damage amount calculation unit 32 calculates the fatigue damage amount of the blade 12 of the wind turbine generator 20 based on the wind condition information acquired by the wind condition information acquisition unit 31. Fatigue damage amount is a term that has the same meaning as fatigue damage rate, life consumption amount, life consumption rate, etc. For example, a no-damage part that is not damaged at all is a numerical value "0" or "0%". It is expressed, for example, a part in a completely destroyed state is expressed by a numerical value "1" or "100%". The fatigue damage amount calculation unit 32 of the present embodiment calculates the fatigue damage amount (reference value of the fatigue damage amount) by using the average wind speed and the turbulent flow intensity acquired by the wind condition information acquisition unit 31.

In FIG. 4A, the load change (load fluctuation applied to the blade 12) for 10 minutes shown in FIG. 3B is cycle-counted by the rainflow method, and the total number of times N is the sum of the load fluctuation Fa and the frequency of each load fluctuation Fa. Is the result of finding and arranging this in a histogram. The above rainflow method is also called a rainflow counting method, and is a method for counting stress frequency or strain frequency for predicting fatigue life in a structure that receives an irregular repetitive variable load. It is one. As shown in FIG. 4A, the load fluctuation Fa acting on the blade 12 has a large number (frequency) of small Fas, and rarely has a large Fa.

On the other hand, FIG. 4B shows the result of converting the distribution of the histogram into a function to obtain the probability density. An example of a probability function suitable for modeling the distribution of load fluctuation Fa is the Weibull distribution. The Weibull distribution can be defined by two parameters, a shape parameter that determines the shape of the distribution, and a dimensional parameter that determines the width of the distribution (the size of the horizontal axis). Thereby, the change of the moment for 10 minutes shown in FIG. 3C can also model the distribution showing the magnitude and the frequency of the moment change Ma as well as the load change.

That is, the wind speed, load, and moment shown in FIGS. 3A to 3C are the average wind speed for 10 minutes, the turbulent flow intensity for 10 minutes, the total number of load fluctuations for 10 minutes, and the shape parameters of the load fluctuation distribution for 10 minutes. It can be converted into representative values such as the scale parameter of the load fluctuation distribution for 10 minutes, the total number of moment fluctuations for 10 minutes, the shape parameter of the moment fluctuation distribution for 10 minutes, and the scale parameter of the moment fluctuation distribution for 10 minutes.

When such a process is performed for another 10 minutes, that is, when the average wind speed and the turbulent flow intensity are different, the relationship between the average wind speed and the turbulent flow intensity and the total number of times, each shape parameter, and each scale parameter is analyzed. can. As a result, if a clear correlation between the average wind speed and turbulent flow intensity and the parameters is clarified, load fluctuations and moment fluctuations can be obtained from the wind conditions. For example, if the scale parameters are arranged by multiplying the average velocity and the turbulent flow intensity, a good correlation can be obtained. On the other hand, there are cases where no clear correlation is observed.

5A and 5B show an analysis example of the shape parameter of the load fluctuation distribution. As shown in FIGS. 5A and 5B, when no correlation is found between the average wind speed and the turbulent flow intensity in all plots, the range of the average wind speed and the turbulent flow intensity is divided into a matrix to form a matrix, and the wind condition. Functionize using the parameters of. The accuracy required for fatigue damage evaluation differs for each parameter. It also depends on the required accuracy of fatigue damage assessment.

Subsequently, from the wind condition information (average wind speed and turbulence intensity), the total number of load fluctuations for 10 minutes, the shape parameter of the load fluctuation distribution for 10 minutes, and the scale parameter of the load fluctuation distribution for 10 minutes can be obtained. The fatigue damage evaluation process after becoming By using the shape parameter and scale parameter of the Weibull distribution, the probability that the value of the load fluctuation takes a certain range can be calculated. Multiplying the total number of 10 minutes gives the number of 10 minutes of load fluctuation of a certain value. The same is true for moments.

FIG. 6 is an example of a fatigue life diagram of a target portion for fatigue evaluation. That is, FIG. 6 uses the relationship between the design SN diagram (relationship between the stress amplitude and the number of fractures) of the material at the target site for fatigue evaluation and the stress generated at the target site for fatigue evaluation when a load is applied. The relationship between the load fluctuation Fa and the number of breaks Nf of the fatigue evaluation target portion (blade 12 in this embodiment) is corrected. As shown in FIG. 6, if the magnitude of the load fluctuation Fa is determined, the number of breaks Nf is determined. Therefore, if the number of breaks corresponding to a certain value of load fluctuation is known, the amount of fatigue damage can be obtained by the cumulative fatigue damage rule. That is, it is possible to estimate the range of load fluctuations and the number of times each of them (the number of breaks) that can be taken under a certain 10-minute wind condition, and thereby the fatigue damage amount for 10 minutes (predicted value of fatigue damage amount). Can be calculated.

If various conditions (individual cases) are organized, as shown in FIG. 7, the amount of fatigue damage is obtained from the average wind speed and turbulent flow intensity (wind condition information). Correlation with the amount of fatigue damage of the blade 12) can be created. As shown in FIGS. 8A and 8B, the contents of each matrix are composed of evaluation formulas for calculating the amount of fatigue damage from the wind condition information representing the average wind speed and the turbulent flow intensity, which are classified for each case.

Here, even under the same wind conditions, the repetitive stress applied to the blade 12 changes depending on the operating condition of the wind turbine generator 20. Therefore, as shown in FIGS. 9A and 9B, the above-mentioned matrix is prepared in advance with changes depending on the operating conditions such as the wind turbine generator 20 being operated and stopped. That is, FIGS. 9A and 9B exemplify a matrix in which the relative relationship between the average wind speed and the change in wind speed (turbulent flow intensity, etc.) is divided for each case while the wind turbine generator 20 is in operation or stopped. is doing. Further, FIG. 10 shows the correlation between the average wind speed and the amount of fatigue damage for each case in the operating state of the wind turbine generator 20. In the correlation of FIG. 10, the broken line has a larger change in wind speed and a larger amount of fatigue damage than the solid line. By using the information shown in FIG. 10, it is possible to obtain the amount of fatigue damage from the case and the average wind speed.

That is, as shown in FIG. 1, the correlation storage unit 39 shows the correlation between the wind condition information representing the average wind speed and the turbulent flow intensity and the amount of fatigue damage of the blade 12 (for example, FIGS. 8A, 8B, 10 and the like). The illustrated information) is stored in advance. Further, the fatigue damage amount calculation unit 32 calculates the fatigue damage amount of the blade 12 in the wind turbine generator 20 with reference to the contents stored in the correlation storage unit 39.

Further, the fatigue damage amount calculation device 30 of the wind turbine generator according to the present embodiment is a load (reference value of load) that can be applied to the blade 12 calculated based on the wind condition information in order to improve the reliability of the fatigue evaluation. And the load that can be applied to the blade 12 calculated based on the measured value of the strain are compared. That is, as shown in FIG. 1, the strain information acquisition unit 33 is in a predetermined portion of the wind turbine generator 20 measured during a certain period of time (in this embodiment, the tower 14 which is a support column provided by the wind turbine generator 20). Get information that represents the strain. Specifically, the strain information acquisition unit 33 is a measurement result of two or more strain gauges including at least the strain gauges 21 and 22 mounted on the tower 14 (for example, the two strain gauges whose mounting positions are shifted by 90 degrees described above). (Measurement result) is acquired.

Further, the first load information calculation unit 34 is the first load representing the average of the loads applied to the blade 12 and the change in the load during a certain period based on the information representing the strain acquired by the strain information acquisition unit 33. Calculate the information. Further, the second load information calculation unit 35 has a second load representing the average of the loads applied to the blade 12 and the change in the load during a certain period based on the wind condition information acquired by the wind condition information acquisition unit 31. Calculate (estimate) information. Further, the fatigue damage amount correction unit 36 was calculated by the fatigue damage amount calculation unit 32 based on the first and second load information calculated by the first and second load information calculation units 34 and 35, respectively. Correct the amount of fatigue damage.

Here, FIG. 11 shows the correlation between the average wind speed and the load change (estimated value of the load change) that can be applied to the blade 12 in the same case as the example shown in FIG. 10 described above. On the other hand, FIG. 12 shows the correlation between the load change ΔF2 on the blade 12 based on the information representing the measured strain, the load change ΔF1 on the blade 12 estimated based on the wind condition information, and the average wind speed. There is. As shown in FIG. 12, the load change ΔF1 estimated based on the wind condition information may be different from the load change ΔF2 on the blade 12 based on the information representing the strain. The reason for this may be that the load calculation formula used at the time of design and the measurement accuracy of appropriate tools are insufficient, but there are other factors such as blade pitch control, generator output, and the effects of unexpected loads due to control malfunctions. , Various cases are possible.

Therefore, as shown in FIG. 1, in the correlation storage unit 39, in addition to the correlation between the wind condition information and the amount of fatigue damage of the blade 12, the strain at the predetermined portion (tower 14) and the first-mentioned first The correlation with the load information, the correlation between the wind condition information and the above-mentioned second load information, and the correlation between the first and second load information and the amount of fatigue damage of the blade 12 are stored in advance. There is. On the other hand, the first load information calculation unit 34, the second load information calculation unit 35, and the fatigue damage amount correction unit 36 calculate the first load information while referring to the contents stored in the correlation storage unit 39. , The second load information is calculated, and the amount of fatigue damage is corrected. This makes it possible to appropriately evaluate the stress applied to the blade 12.

Further, the fatigue damage amount integrating unit 37 integrates a plurality of fatigue damage amounts corrected by the fatigue damage amount correction unit 36 in units of a certain period. Here, the fixed period described above is a predetermined time interval such as 5 minutes, 10 minutes, 20 minutes, etc., and the fatigue damage amount integrating unit 37 determines the fixed period as 5 minutes. The amount may be integrated with the amount of fatigue damage obtained with a fixed period of 10 minutes. On the other hand, the fatigue damage amount output unit 38 outputs the fatigue damage amount integrated by the fatigue damage amount integration unit 37. The fatigue damage amount output unit 38 may be configured as a display device for visually displaying the fatigue damage amount in, for example, a table or a graph, or may be displayed separately from the fatigue damage amount calculation device 30 of the wind turbine generator. It may be configured as an interface for displaying and outputting the amount of fatigue damage to the device.

Next, a method of calculating the amount of fatigue damage by the fatigue damage amount calculation device 30 of the wind turbine generator will be described with reference to the flowchart shown in FIG. As shown in FIG. 13, first, the wind condition information acquisition unit 31 is the average of the wind speeds measured during a certain period at the installation location of the wind turbine generator 20 (by the wind condition measuring instrument 23 provided in the nacelle 15). And the wind condition information showing the change of the wind speed is acquired (S1). Next, the fatigue damage amount calculation unit 32 calculates the fatigue damage amount of the blade 12 in the wind turbine generator 20 based on the wind condition information acquired by the wind condition information acquisition unit 31 (S2).

Further, the strain information acquisition unit 33 acquires information representing the strain at a predetermined portion (axial direction of the tower 14) of the wind turbine generator 20 measured by the strain gauges 21 and 22 during a certain period (S3). Next, the first load information calculation unit 34 represents the average of the loads applied to the blade 12 and the change in the load during a certain period based on the information representing the strain acquired by the strain information acquisition unit 33. Calculate the information (S4). On the other hand, the second load information calculation unit 35 has a second load representing the average of the loads applied to the blade 12 and the change in the load during a certain period based on the wind condition information acquired by the wind condition information acquisition unit 31. Calculate the information (S5).

Subsequently, the fatigue damage amount correction unit 36 is calculated by the fatigue damage amount calculation unit 32 based on the first and second load information calculated by the first and second load information calculation units 34 and 35, respectively. The amount of fatigue damage is corrected (S6). Next, when the number (number) of the corrected fatigue damage amount exceeds the specified number (YES in S7), the fatigue damage amount integrating unit 37 has the fatigue damage amount correction unit 36 in the unit of the fixed period. A plurality of fatigue damage amounts corrected by the above are integrated (S8). Further, the fatigue damage amount output unit 38 displays and outputs the fatigue damage amount integrated by the fatigue damage amount integration unit 37 to, for example, a display device (S9).

As described above, according to the wind power generation system 10 including the wind turbine generator fatigue damage amount calculation device 30 and the wind turbine generator fatigue damage amount calculation method according to the present embodiment, sensors are added and high-performance sampling is performed. It is possible to easily obtain a highly reliable fatigue damage amount for the blade 12 while suppressing the installation of the device and the increase in monitoring cost due to the addition of a high-performance computing device for analyzing and processing a huge amount of data. That is, according to the present embodiment, the analysis accuracy of the fatigue life of the wind turbine generator 20 can be easily improved. Therefore, the power generation company can generate the wind turbine based on the analysis result of the fatigue life with the improved analysis accuracy. It is possible to formulate an appropriate inspection, repair, renewal plan, etc. for the machine 20.

<Second embodiment>
Next, the second embodiment will be described with reference to FIG. In FIG. 14, the same components as those in the first embodiment shown in FIG. 1 are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 14, the wind power generation system 50 according to the second embodiment replaces the fatigue damage amount calculation device 30 of the wind turbine generator provided in the wind power generation system 10 of the first embodiment. The machine is provided with a fatigue damage amount calculation device 70. The fatigue damage amount calculation device 70 of the wind turbine generator further includes a wind condition information output unit 71 and a load information output unit 72 in addition to the configuration of the fatigue damage amount calculation device 30 of the wind turbine generator.

The wind condition information output unit 71 outputs the wind condition information acquired by the wind condition information acquisition unit 31 and the average wind speed (average wind speed) and the change in wind speed (turbulent flow intensity) assumed at the time of designing the wind turbine generator 20. The wind condition information to be represented is also output. On the other hand, the load information output unit 72 includes the first load information and the second load information calculated by the first and second load information calculation units 34 and 35, respectively, the first load information, and the second load information. Outputs at least one of the information indicating the difference from the load information of. The wind condition information output unit 71 and the load information output unit 72 may be configured as a display device that visually displays each of the above wind condition information and information indicating the above difference in, for example, a table or a graph. However, it may be configured as an interface for displaying and outputting each wind condition information and information indicating the difference to a display device separate from the fatigue damage amount calculation device 30 of the wind turbine generator.

Therefore, according to the wind power generation system 50 including the fatigue damage amount calculation device 70 of the wind turbine generator according to the present embodiment, the actual wind condition with respect to the wind condition assumed at the time of design and the responsiveness of the wind turbine generator based on the actual wind condition. For example, it becomes possible for a power generation company to easily grasp what kind of situation the power generation company is in. As a result, the power generation company can realize the beneficial operation of the wind turbine generator.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and the equivalent scope thereof.

10,50 ... Wind turbine power generation system, 12 ... Blade, 14 ... Tower, 20 ... Wind turbine generator, 21,22 ... Strain gauge, 23 ... Wind condition measuring instrument, 30, 70 ... Wind turbine generator fatigue damage calculation device, 23 ... Wind condition measuring instrument, 31 ... Wind condition information acquisition unit, 32 ... Fatigue damage amount calculation unit, 33 ... Strain information acquisition unit, 34 ... First load information calculation unit, 35 ... Second load information calculation unit, 36 ... Fatigue damage amount correction unit, 37 ... Fatigue damage amount integration unit, 38 ... Fatigue damage amount output unit, 39 ... Correlation storage unit, 71 ... Wind condition information output unit, 72 ... Load information output unit.

Claims (10)

The wind condition information acquisition unit that acquires the average wind speed measured at the installation location of the wind turbine generator and the change in wind speed during a certain period of time, and the wind condition information acquisition unit.
A fatigue damage amount calculation unit that calculates the fatigue damage amount of the blade of the wind turbine generator based on the acquired wind condition information, and a fatigue damage amount calculation unit.
A strain information acquisition unit that acquires information representing strain at a predetermined portion of the wind turbine generator measured during a certain period of time, and a strain information acquisition unit.
Based on the acquired information representing the strain, the first load information calculation unit that calculates the first load information representing the average load applied to the blade and the change in the load during the fixed period, and the first load information calculation unit.
Based on the acquired wind condition information, a second load information calculation unit that calculates a second load information representing an average load applied to the blade and a change in the load during the fixed period, and a second load information calculation unit.
A fatigue damage amount correction unit that corrects the calculated fatigue damage amount based on the calculated first and second load information, respectively.
A fatigue damage amount integrating unit that integrates a plurality of fatigue damage amounts corrected by the fatigue damage amount correcting unit in units of the fixed period, and a fatigue damage amount integrating unit.
A fatigue damage calculation device for a wind turbine generator equipped with. Correlation between the wind condition information and the amount of fatigue damage of the blade, the correlation between the strain at the predetermined portion and the first load information, the correlation between the wind condition information and the second load information, Further, a correlation storage unit for preliminarily storing the correlation between the first and second load information and the amount of fatigue damage of the blade is provided.
The fatigue damage amount calculation unit, the first load information calculation unit, the second load information calculation unit, and the fatigue damage amount correction unit refer to the contents stored in the correlation storage unit while referring to the contents stored in the correlation storage unit. The fatigue damage amount is calculated, the first load information is calculated, the second load information is calculated, and the fatigue damage amount is corrected.
The fatigue damage amount calculation device for a wind turbine generator according to claim 1. The wind condition information includes information representing the difference between the maximum wind speed and the minimum wind speed during the fixed period.
The fatigue damage amount calculation device for a wind turbine generator according to claim 1 or 2. The wind condition information includes information representing the turbulent flow intensity obtained by dividing the standard deviation of the change in wind speed during a certain period by the average of the wind speed.
The fatigue damage amount calculation device for a wind turbine generator according to any one of claims 1 to 3. The strain information acquisition unit acquires information representing the strain of the columns included in the wind turbine generator.
The fatigue damage amount calculation device for a wind turbine generator according to any one of claims 1 to 4. Fatigue damage amount output unit that outputs the accumulated fatigue damage amount,
The fatigue damage amount calculation device for a wind turbine generator according to any one of claims 1 to 5, further comprising. A wind condition information output unit that outputs a combination of the wind condition information acquired by the wind condition information acquisition unit and the wind condition information indicating the average wind speed and the change in the wind speed assumed at the time of designing the wind turbine generator.
The fatigue damage amount calculation device for a wind turbine generator according to any one of claims 1 to 6, further comprising. A load information output unit that outputs at least one of the first load information, the second load information, and information indicating the difference between the first load information and the second load information.
The fatigue damage amount calculation device for a wind turbine generator according to any one of claims 1 to 7. The fatigue damage amount calculation device for the wind turbine generator according to any one of claims 1 to 8.
With the wind turbine generator
Wind power generation system equipped with. Steps to acquire wind condition information showing the average wind speed and changes in wind speed measured during a certain period at the installation location of the wind turbine generator, and
A step of calculating the amount of fatigue damage to the blades of the wind turbine generator based on the acquired wind condition information, and
A step of acquiring information representing strain at a predetermined part of the wind turbine generator measured during a certain period of time, and
Based on the information representing the acquired strain, the step of calculating the first load information representing the average load applied to the blade and the change in the load during the fixed period, and the step of calculating the first load information.
Based on the acquired wind condition information, a step of calculating a second load information representing the average load applied to the blade and a change in the load during the fixed period, and a step of calculating the second load information.
A step of correcting the calculated fatigue damage amount based on the calculated first and second load information, respectively, and a step of correcting the calculated fatigue damage amount.
A step of accumulating a plurality of corrected fatigue damage amounts in the unit of the fixed period, and
A method for calculating the amount of fatigue damage of a wind turbine generator having.

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