TWI403706B - Load measuring apparatus and method and program product - Google Patents

Abstract

An object of the invention is to calibrate a load based on data collected under wide observation conditions and promptly calibrate loads of a plurality of wind turbine blades. There is provided a load measuring apparatus (1) applied to a wind turbine in which a pitch angle of a wind turbine blade (10) is variable, the apparatus including: a sensor for obtaining a distortion of the wind turbine blade (10); a load calculating unit (20) having a function expressing a relation between the distortion of the wind turbine blade (10) and a load on the wind turbine blade (10), for obtaining the load on the wind turbine blade (10) by applying to the function the distortion based on measurement data of the sensor; and a calibration unit (30) for calibrating the function based on the measurement data of the sensor obtained in a pitch angle range and a rotational speed range of the wind turbine blade (10) in which a variation between maximum and minimum aerodynamic torques is equal to or less than a predetermined value.

Description

Load measuring device and method, and program product

The present invention relates to a load measuring device and method, and a programmer.

In general, in a wind power generator, a sensor for measuring a load applied to a wind turbine blade is attached to a blade root portion or the like, and is provided by a sensor via the sensor. The measured data is processed and the load is calculated. However, due to the individual differences that occur during the manufacture of the wing or the installation of the sensor, the relationship between the load applied to each wind turbine blade and the deformation is not constant, therefore, the proposal Yes: For each windmill blade, the load is measured and the load value is corrected.

[Patent Document 1] US Patent No. 6940186

In the prior art, the above-described load is corrected by fixing the windmill rotor so as not to rotate via a human hand (using a lock pin or the like), and the load of each wind turbine blade is measured in this state.

However, the above-mentioned correction work is necessary for each windmill separately, and in order to correct all the windmills, it is necessary to fix the rotor by hand, and when it is provided with hundreds of wind power generators In the case of a scale wind power plant, it takes a lot of work time. Further, since the relationship between the load applied to the wind turbine blade and the deformation is different for each wind turbine and each wind turbine blade, it is necessary to repeatedly perform the correction work for each of the wind turbine blades. Further, in the work of moving the flap to a specific position (angle) by using a rotary motor and fixing it, it takes time, and the work cannot be smoothly performed, which has a problem of poor productivity.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a load measuring device, method, and program that can efficiently perform correction of a load on a wind turbine blade without depending on observation conditions.

According to a first aspect of the present invention, a load measuring device is a load measuring device that is applied to a wind turbine in which a tilt angle of a wind turbine blade is variable, and is characterized in that: a sensor is provided for The deformation of the wind turbine blade is taken out; and the load calculation means includes a function for expressing the relationship between the deformation of the wind turbine blade and the load of the wind turbine blade, and using the sensor according to the measurement in the function And the correction means is based on the range of inclination of the wind turbine blade when the deviation between the maximum value and the minimum value of the air force torque caused by the wind speed is equal to or less than a specific value. The function of the aforementioned sensor obtained in the range of the number of rotations is corrected for the function.

According to this configuration, since the correction means for correcting the function held by the load calculating means is provided, the correction means is based on the deviation between the maximum value and the minimum value of the air force torque caused by the wind speed. The function is corrected by measuring the inclination of the wind turbine blade at a specific value or less and the measurement data of the sensor obtained in the range of the number of rotations. Therefore, the conditions of the wind speed can be made wide.

In the above-described load measuring device, the correction means may be configured such that the sensor is obtained based on a range of inclination angles and a range of rotation of the wind turbine blade whose air force torque is equal to or less than a specific value. The measurement data is used to correct the aforementioned function.

As a result, since the measurement data of the sensor obtained in the range of the inclination angle of the wind turbine blade whose air torque torque is equal to or less than a specific value is used, the influence of the air force torque can be ignored.

In the above-described load measuring device, the correction means may be configured to include a table for the load of the wind turbine blade when there is no wind, and the inclination angle of the wind turbine blade and the azimuth angle ( The azimuth angle) and the load acquisition means obtain the load of the wind turbine blade corresponding to the inclination angle and the azimuth angle of the wind turbine blade when the measurement data is acquired via the sensor from the table; and the deformation calculation a method for calculating a deformation of the wind turbine blade from measurement data of the sensor; and a parameter calculation means based on a load of the wind turbine blade obtained by the load acquisition means and calculated by the deformation calculation means The relationship between the deformations is used to correct the parameters of the aforementioned function.

In this way, in the correction means, in the table, the load of the wind turbine blade when there is no wind and the inclination angle of the wind turbine blade and the azimuth angle are additionally related, and the load acquisition means is obtained from the table, and the corresponding feeling is obtained from the table. The inclination of the wind turbine blade and the load of the azimuth wind turbine blade when the measurement data is obtained are obtained by the detector, and then the deformation of the wind turbine blade is calculated from the measurement data of the sensor via the deformation calculation means, and then the parameter calculation means is used. The parameters of the function are corrected based on the relationship between the load of the wind turbine blade obtained by the load obtaining means and the deformation calculated by the deformation calculating means.

Therefore, since the table provided by the correction means has a load corresponding to the azimuth angle and the inclination angle, it is possible to easily wind the windmill at this time as long as the azimuth and the inclination angle at the time of obtaining the measurement data are known. The load of the blade is mastered. Moreover, since the parameters of the function are corrected based on the relationship between the deformation of the wind turbine blade calculated based on the measurement data and the load determined based on the measurement data, the measurement data can be accurately measured with high accuracy. The skewness is corrected.

In the above-described load measuring device, the correction means may be configured to take out the load based on the load of the wind turbine blade obtained by the load acquiring means and the measurement data of the sensor. The measurement data of the aforementioned sensor at the time of load, and using the measurement data when there is no load, the OFFSET correction is performed on the measurement data of the aforementioned sensor.

As a result, since the measurement data under the no-load included in the measurement data of the sensor is extracted and offset, the accuracy of the measurement data can be improved.

In the above-described load measuring device, the sensor may be configured such that the pair of first sensors are provided at positions facing the wind turbine blade and facing each other, and The pair of second sensors are disposed at positions different from the first sensor and held at the position opposite to the wind turbine blade.

Thereby, the load in the different direction at one wind turbine blade can be measured. For example, if the first sensor is placed on the front and back surfaces of the wind turbine blade and the second sensor is placed on the edge side of the wind turbine blade, it is possible to measure that the wind turbine blade is compliant by the sensors. The load in the direction of the feather side and the load in the direction of the fine side.

In the above-described load measuring device, the sensor may be configured such that the pair of third sensors are provided at positions facing each other while holding the wind turbine blade, and The position different from the first sensor and the second sensor is provided at a position parallel to any of the first sensor or the second sensor.

Thereby, it can be used in the measurement of information other than the load via the 3rd sensor.

According to a second aspect of the present invention, a load measuring device is applied to a load measuring device in which a wind turbine blade has a variable inclination angle, and is characterized in that: a sensor is provided for: Obtaining a deformation of the wind turbine blade; and calculating a weight calculation means for expressing a relationship between the deformation of the wind turbine blade and the load of the wind turbine blade, and using the sensor according to the function Measuring the deformation of the data to obtain the load of the wind turbine blade; and correcting means, when the wind speed is 3 meters or less, the rotation is 180 degrees by the first azimuth angle and from the first azimuth angle. The function is corrected for the measurement data of each of the sensors when the inclination angle is set to the minimum inclination angle and the maximum inclination angle at the two points formed by the second azimuth angle.

According to this configuration, the correction means for correcting the function held by the load calculating means is provided, and the correction means is based on the first azimuth angle when the wind speed is 3 meters or less. The function of each sensor when the inclination angle is set to the minimum inclination angle and the maximum inclination angle at two points formed by the second azimuth angle of the first azimuth angle is corrected, and the function is corrected. Therefore, the function can be corrected based on a small amount of measurement data.

A third aspect of the present invention is a load measuring method, which is applied to a load measuring method in a wind turbine in which a tilt angle of a wind turbine blade is changed, and is characterized in that the deformation of the wind turbine blade is taken out; Calculating the relationship between the deformation of the windmill blade and the load of the wind turbine blade, and extracting the load of the windmill blade by using the deformation of the measurement data according to the sensor in the function; The function of the sensor obtained by the inclination angle range and the rotation number range of the wind turbine blade when the deviation between the maximum value and the minimum value of the air force torque due to the wind speed is equal to or less than a specific value is used for the function. Make corrections.

According to a fourth aspect of the present invention, a load measuring program is applied to a load measuring program in a wind turbine in which a tilt angle of a wind turbine blade is variable, wherein the load measuring program is used to cause a computer The following processing is performed: the first processing is provided with a function of expressing the relationship between the deformation of the wind turbine blade and the load of the wind turbine blade, and by using the measurement data according to the sensor in the function. Deformation to extract the load of the wind turbine blade; and the second process is based on the range and rotation of the wind turbine blade when the deviation between the maximum value and the minimum value of the air force torque due to the wind speed is equal to or less than a specific value The function of the aforementioned sensor obtained in the range is corrected to correct the function.

A fifth aspect of the present invention is a method for measuring a load, which is applied to a load measuring method in a wind turbine in which a tilt angle of a wind turbine blade is variable, and is characterized in that the deformation of the wind turbine blade is provided The relationship between the load of the windmill blade is a function of performance, and the load of the wind turbine blade is taken out by using the deformation of the measurement data according to the sensor in the function; when the wind speed is less than 3 meters Each of the above-described sensors when the inclination angle is set to the minimum inclination angle and the maximum inclination angle at two points formed by the first azimuth angle and the second azimuth angle rotated by 180 degrees from the first azimuth angle The measurement data is used to correct the function.

According to a sixth aspect of the present invention, in a load measuring program, a load measuring program applied to a wind turbine in which a tilt angle of a wind turbine blade is variable is characterized in that the load measuring program is used to make a computer The following processing is performed: the first processing is provided with a function of expressing the relationship between the deformation of the wind turbine blade and the load of the wind turbine blade, and by using the measurement data according to the sensor in the function. When the deformation is performed, the load of the wind turbine blade is taken out; and when the wind speed is 3 meters or less, the second processing is performed by the first azimuth angle and the first azimuth angle by 180 degrees. The function is corrected by setting the inclination of each of the two sensors at the two azimuth angles to the measurement data of each of the sensors at the minimum inclination angle and the maximum inclination angle.

According to the present invention, it is possible to efficiently obtain the correction for the load on the wind turbine blade without depending on the observation conditions.

Hereinafter, one embodiment of the load measuring device, method, and program of the present invention will be described with reference to the drawings.

[First Embodiment]

Fig. 1 is a view showing a schematic configuration of a wind turbine generator to which the load measuring device 100 of the present embodiment is applied. The wind power generator 1 of the present embodiment is a wind turbine in which the inclination angle of the wind turbine blade 10 is made variable.

The wind power generator 1, generally as shown in Fig. 1, is provided with a strut 2, and a nacelle 3 disposed at an upper end of the strut 2, and is configured to be rotatable about a slightly horizontal axis. A rotor head (hub) 4 is provided at the nacelle 3. At the rotor head 4, three wind turbine blades 10 are radially mounted around the axis of rotation thereof. Thereby, the force of the wind blown from the direction of the rotation axis of the rotor head 4 to the wind turbine blade 10 is converted into the power for rotating the rotor head 4 around the rotation axis, and the power system is Transformed into electrical energy.

At each wind turbine blade 10, a plurality of sensors (sensing portions) 7 for extracting deformation of the wind turbine blade 10 are provided. The sensor 7, for example, is a FBG (Fiber Bragg Grating sensor). FBG is a fiber optic sensor that is characterized by a Bragg grating, and detects changes in grating spacing due to deformation and thermal expansion according to the wavelength change of the reflected light.

Further, the rotor head 4 is provided with a signal processing unit (not shown) that receives the measurement result of the sensor 7 (sensing unit).

Specifically, each of the wind turbine blades 10 is provided with a first sensor, a second sensor, and a third sensor. Each of the first sensor, the second sensor, and the third sensor includes a pair of sensors that are disposed at positions facing the wind turbine blade 10 and are opposed to each other. Preferably, the first sensor and the second sensor are provided such that straight lines connecting the two sensors constituting the two are slightly perpendicular to each other. The third sensor is, for example, a sensor used for temperature compensation, and is disposed at the periphery of the first sensor or the second sensor.

Fig. 2 is a view for explaining the position of the sensor 7 (sensing portion) mounted on the wind turbine blade. As generally shown in FIG. 2, in the present embodiment, the sensor 7, for example, is disposed at a position of 1.8 meters from the root of the wind turbine blade 10. By root is meant the boundary between the general windmill blade 10 and the rotor head 4 as shown in FIG. In the present embodiment, this root portion is referred to as a "fan blade root portion".

Fig. 3 is a cross-sectional view showing the position where the sensor 7 is mounted at a position separated from the root of the fan blade 10 by 1.8 meters. In FIG. 3, a sensor A3 is provided on the back side 21 of the wind turbine blade 10, and a sensor A1 is provided on the abdomen side 22 to constitute a first sensor. Further, at the same position as A3, the sensor A5 is provided, and at the same position as A1, the sensor A6 is provided to constitute the third sensor. Further, a sensor A2 is provided in the direction of the leading edge 23 of the wind turbine blade 10, and a sensor A4 is provided in the direction of the trailing edge 24 to constitute a second sensor.

Fig. 4 is a view schematically showing the arrangement of the sensor 7 mounted on the wind turbine blade 10 when viewed from the root of the fan blade 10. As shown in FIG. 4, in the present embodiment, the position where the sensor A1 is disposed is defined as HP, the position where the sensor A3 is disposed is defined as LP, and the position of the sensor A2 is set. Defined as LE and defines the location where sensor A4 is set as TE. Further, in Fig. 4, the tilt angle is an inclination angle of the rotating surface of the wind turbine blade 10 with respect to the vertical axis of the tower, so that even if the wind turbine blade 10 is deformed by the wind force even during operation, The wind turbine blade 10 is prevented from coming into contact with the tower, and such an inclination angle is provided. Regarding this inclination angle, it can be ignored or considered in the calculation described later.

Next, the configuration of the load measuring device 100 of the present embodiment will be described in detail.

FIG. 5 is a functional block diagram showing the functions of the load measuring device 100.

As shown in FIG. 5, the load measuring device 100 of the present embodiment includes a load calculating unit (load calculating means) 20 and a correcting unit (correcting means) 30.

The load calculating unit 20 has a function of expressing the relationship between the deformation of the wind turbine blade and the load of the wind turbine blade 10, and the deformation obtained based on the measurement data of the sensors A1 to A6 is used in this function. The load of the windmill blade 10 is taken out.

The correction unit 30 is based on the measurement data of the sensor obtained in the range of the inclination angle of the wind turbine blade 10 and the range of the rotation number based on the deviation between the maximum value and the minimum value of the air force torque caused by the wind speed. To correct the above function. In addition, it is more preferable to use the measurement data of the sensor obtained in the period in which the condition that the air force torque is equal to or less than the specific value of the inclination angle range of the wind turbine blade 10 and the range of the rotation number range is used.

Here, the measurement data of the sensor used in the correction of the function performed by the correction unit 30 will be specifically described.

Fig. 6 is a view showing that the wind turbine blade 10 is changed from the windward side (the inclination angle of 21 degrees) to the feather side (the inclination angle of 109 degrees), and the air force torque is changed to each wind speed until the wind turbine blade 10 is stopped. The picture is shown below (from wind speed 4m per second to wind speed 12m per second). The angle of inclination of 21 degrees or 109 degrees refers to the angle of the wind turbine blade 10 when the position of the blade reference line determined when the wind turbine blade 10 is attached to the wind turbine rotor 3 is set to 0 degrees. Here, the inclination angle of 0 degrees refers to the angle on the reference line of the blade defined on the root profile of the blade, and the angle formed by the line with the plane of the rotor is the inclination angle.

When Fig. 6 is obtained, in the range of inclination angle of 21 to 45 degrees, the speed is 2.5 degrees per second; in the range of inclination angle of 45 degrees to 109 degrees, 3 speeds are used to make 3 The windmill blades 10 are simultaneously changed, and the measurement data at the three windmill blades 10 at this time are obtained. Further, the wind turbine blade 10 is rotated by changing the inclination angle, and is idling. The idling is a state in which the wind turbine blade 10 is rotated within a range in which the wind power generator 1 does not generate electric power (for example, a state in which the wind turbine blade 10 is rotated at a low speed).

In addition, since the same processing is performed for all of the three wind turbine blades 10, in the following description, only one wind turbine blade 10 will be described.

As shown in FIG. 6 , in general, a period in which the wind power generator is generating power, and an air force that is a force to stop the rotation of the motor is strongly extended by expanding the tilt angle to the feather side for stopping or the like. The period of action is set to area A. As shown generally in Fig. 6, in the area A, different air force torques are applied in response to the wind speed. Then, when the area A is more right (in other words, the inclination is larger than 60 degrees, and the number of rotations of the generator is 0 to 300 rpm (in the case of frequency 60 Hz)), the torque is applied at any wind speed. The value is about -300 kN or more, and it is a very small torque that can ignore the influence of the air force torque.

In addition, in FIG. 6, the condition of the range of the number of rotations on the right side of the area A is 0 to 300 rpm, but the present invention is not limited thereto, and may be set in accordance with the frequency. For example, in the case of 50 Hz, the condition of the range of the number of rotations may be set to 0 to 250 rpm.

In this manner, the correction unit 30 is configured to use measurement data obtained in a portion that is not in the region A (that is, in a range that is an air force torque that does not depend on the wind speed). In other words, it is assumed that the measurement data obtained in the range of 60 to 109 degrees of the inclination of the range in which the deviation between the maximum value and the minimum value of the air force torque is equal to or less than a specific value is used. In addition, the basis for the use of information that is not the area of the area A will be described later.

More specifically, the correction unit 30 includes a table 31, a load acquisition unit (load acquisition means) 32, a deformation calculation unit (deformation calculation means) 33, and a parameter calculation unit 34.

The correction unit 30 obtains the measurement data of the sensor 7 when there is no load based on the load of the wind turbine blade 10 and the measurement data of the sensor 7 obtained by the load acquisition unit 32, and uses the measurement data of the sensor 7 when the load is not applied. The measurement data at the time of no load is used to perform offset correction (OFFSET) on the measurement data of the sensor 7. Thereby, since the measurement error included in the sensor 7 itself is taken into consideration, the accuracy of the correction can be improved.

Table 31 is a connection between the load at the root of the fan blade 10 and the inclination and azimuth of the windmill blade 10 in the absence of wind (corrected to the desired environmental conditions), for example, as in Figure 7 The general list is shown and stored with a combination of the azimuth and the inclination of the wind turbine blade 10 with the values of the load α ₁ , α ₂ , α ₃ at the root of the blade, α ₄ ,...

The azimuth angle described above is an angle formed between a specific reference at the rotational surface of the wind turbine blade 10 and the axis of the wind turbine blade 10 as shown in Fig. 8. In the present embodiment, the wind turbine blade is used. 10 is used as a reference when the position is at the top. Therefore, when the windmill blade 10 is positioned at the uppermost portion of the windmill, the azimuth angle is 0 degrees, and when the position is at the lowermost portion, the azimuth angle is 180 degrees.

In the general table shown in Fig. 7, the momentum at the root of the fan can be calculated at the position of each of the sensors A1 to A4 by the equation (1) shown below. The momentum caused by its own weight is obtained by coordinate transformation of these momentums.

M=9.8×W×1 _g ×sinθ‧cosβ [Nm] (1)

In the above formula (1), W is the weight of the wind turbine blade 10, and 1 _g is the position of the center of gravity measured from the root of the blade of the wind turbine blade 10 (the known value in the manufacturing stage), and θ is The function of the azimuth and the tilt angle, β is a function of the tilt angle and the tilt angle.

The load obtaining unit 32 obtains the load at the root of the fan blade 10 corresponding to the inclination angle and the azimuth angle of the wind turbine blade 10 when the measurement data is acquired via the sensor 7 from the table 31.

The deformation calculating unit 33 calculates the deformation of the wind turbine blade 10 from the measurement data of the sensor 7. Specifically, the deformation wavelength is extracted from the measurement data of the sensor 7, and the deformation wavelength is converted into deformation according to a specific function. More specifically, the measurement data of the sensor 7 is converted into a numerical value and a deformed wavelength obtained as a numerical value in a signal processing unit (not shown) provided at the rotor head 4. , transformed into deformation ε. Further, the deformation ε can be obtained by the following formula (2).

ε=P _e {(λ-λ _i )-α(λ _T -λ _Ti )} (2)

In the above formula (2), λ is the measurement data due to the first sensor (second sensor), and λ _i is the load without the first sensor (second sensor). In the measurement data, λ _T is the measurement data caused by the third sensor, λ _Ti is the calculation data when there is no load due to the third sensor, and p _e is the deformation optical constant (809 με/nm). ), α is the temperature compensation coefficient (2.2). Further, λ _i is an average value of the measurement data, and can be extracted by the following formula (3).

λ _i =(λ _max +λ _min )/2 (3)

In the above formula (3), λ _max represents the maximum peak of the data, and λ _mix represents the minimum peak.

In this way, since the sensors A1 and A3 constituting the first sensor and the sensors A2 and A4 constituting the second sensor respectively calculate the deformation, the calculation is performed. Deformation. Further, by calculating the difference between the deformations obtained by the sensors A1 and A3 constituting the first sensor, the flap direction with respect to the wind turbine blade 10 (the direction of HP-LP in FIG. 4) is calculated. The deformation ε _F and the edge direction of the wind turbine blade 10 are calculated by calculating the difference between the deformations obtained by the sensors A2 and A4 constituting the second sensor (LE-TE in Fig. 4) The direction of the deformation ε _E .

The parameter calculation unit 34 corrects the parameter of the function based on the relationship between the load of the wind turbine blade 10 acquired by the load acquisition unit 32 and the deformation calculated by the deformation calculation unit 33. Specifically, it is a measurement data in which the metadata of the deformations ε _F and ε _E are calculated, and the load at the root of the blade of the wind turbine blade 10 is added in accordance with the azimuth angle and the inclination angle at the time of acquisition. And the relationship between the deformations ε _F and ε _E constitutes a new function, and the coefficients of the function possessed by the load calculating unit 20 are corrected using the coefficients of the new function. At this time, the new function is made one for the flap direction and one for the edge direction.

For example, in order to convert the above-described deformation ε into momentum at the position of the sensor, the following formula (4) is used. Further, d is the inner diameter of the wind turbine blade 10 at the installation position of the sensor 7 (1.8 meters from the root of the blade), and L is the number of the wind turbine blade 10 (L = 1, 2, 3), E system For the fan-shaped material (FRP), the I-frame is the secondary momentum of the profile at the position where the _sensor is placed, and the M _sensor is the bending momentum (load) at the position where the sensor is set, ε _{2L- 1} and ε _2L are deformations obtained from measurement data of a pair of sensors (first sensor or second sensor), ε _{2L-1, 0} and ε _{2L, and 0} is the first sensing The initial value of the deformation of the device or the second sensor.

[Expression 1]

Hand, if the ratio between the moment M at _{the root} of the root portion of the fan 10 and wind turbine blade moment M at position 7 of the sensor is disposed (e.g., fan wind turbine blade root portion 10 from the place of 1.8m) of the _sensor When β (>1) is set, the following formula can be obtained.

[Expression 2]

herein:

As shown in the above formula (5), the momentum M _root at the root of the fan uses the coefficients a and b as parameters and acts as a pair of sensors (first sensor or second sense). The deformation caused by the transformer is expressed as a linear function of the variable.

Therefore, when the horizontal axis is the deformation ε _F or ε _E and the vertical axis is the graph of the momentum M _root at the azimuth angle and the inclination angle, the calculation is based on the linear function. The slope a and the intercept b can be calculated by taking the coefficients a and b as parameters.

Next, a method of graphing the above-described one-time function will be described.

The horizontal axis is the deformation ε _F of the flap direction at each wind turbine blade 10 and the deformation ε _{E of the} edge direction, and the vertical axis is the deformation ε _F and the deformation ε _E obtained from Table 31. The corresponding load (momentum) M _{root is plotted} and the slope a and intercept b are extracted from this chart. More specifically, a general graph as shown in FIG. 9 is used, and according to such a graph, the coefficients a and b of the flap direction of the respective wind turbine blades 10 and the case of the edge direction are used. The coefficients a and b are calculated. For example, as a parameter of the flap direction at the first wind turbine blade 10#1, a=2.014×10 ⁹ and b=-0.448×10 ^{3 are set} . Similarly, for the wind turbine blade 10#2 and the wind turbine blade 10#3, the coefficients a and b of the flap direction and the edge direction are calculated, respectively.

In this manner, the parameter calculation unit 34 outputs the coefficients a and b to the load calculation unit 20 when the coefficients a and b are calculated. As a result, the parameter of the function of the load calculation unit 20 is corrected, and the measurement data acquired from the sensor is used as a function of the load calculation unit 20, and the momentum at the root of the blade is obtained. Corrected.

Next, the operation of the correction unit 30 of the load measuring device of the present embodiment will be described. In addition, since the processing performed by each wind turbine blade 10 is the same, in the following description, the processing performed by one wind turbine blade 10 is mentioned as an example.

First, in the present embodiment, the inclination angle is changed from 60 degrees to 109 degrees, and the measurement data of each of the sensors A1 to A6 at this time is obtained. The measurement data is given to the load acquisition unit 32 of the correction unit 30.

The load acquisition unit 32 refers to the table 31, and reads the load at the root of the blade associated with the information between the azimuth and the inclination of the measurement data measured from each of the sensors A1 to A6. Next, the load acquisition unit 32 is formed for each sensor, and the vertical axis represents the measurement data of the sensor and the horizontal axis represents the load at the root of the fan (refer to FIG. 10), and then For each graph, the deformation wavelength when the value of the load on the horizontal axis is "0" is read. This value is the measurement data of the sensor when there is no load, that is, it is equivalent to the OFFSET value of each sensor. The load acquisition unit 32 is information on the load at the root of the fan read from the table 31 and the information of each sensor when the load is obtained, simultaneously with the OFFSET value of each sensor. It is output to the deformation calculation unit 33. In this manner, the load acquisition unit 32 obtains the OFFSET value of each sensor, and in the subsequent processing, the measurement error included in the sensor itself is corrected, and the load can be accurately measured. Degree improvement.

The deformation calculation unit 33 extracts the distortion wavelengths from the measurement data of the sensors A1 to A6, and uses the measurement data calculated from the respective sensors and the measurement data when there is no load, and uses the above ( The deformation (self-heavy momentum) ε at each sensor position is calculated by the equation 2). For example, the deformation ε _{A1 A1} of the sensor, by the following system of (2) 'and the formula is obtained out.

ε _A1 =P _e {(λ _HP -λ _HPi )-α(λ _HPT -λ _HPT1 )} (2) '

In the above (2) ' , λ _HP is the deformation wavelength data of the sensor A1, and λ _HPT is the deformation wavelength data of the sensor A5 for temperature compensation provided around the sensor A1, λ _HPi It is the OFFSET value of the sensor A1 (measurement data when there is no load), and λ _HPTi is the OFFSET value of the sensor A5 (measurement data when there is no load).

The deformation calculating unit 33 calculates the deformation ε for each of the sensors A3, A2, and A4 by the same calculation processing. Thereby, the deformation ε system is calculated from the total of four ε _A1 , ε _A2 , ε _A3 , and ε _A4 . When the deformation ε _{A1 to A4} are calculated for each of the sensors A1 to A4, the deformation calculation unit 33 outputs the information of the load at the root of the fan input from the load acquisition unit 32. The parameter calculation unit 34 is provided.

The parameter calculation unit 34 is based on the relationship between the deformations 歪 ε _{A1 to A4 of the} respective sensors and the load at the root of the fan input from the load acquiring unit 32. The parameters showing the relationship between the deformation of the windmill blade 10 and the load of the wind turbine blade 10 at the root of the blade are corrected.

Specifically, the relationship between the load of the wind turbine blade 10 at the root of the blade and the deformation of the wind turbine blade 10 is expressed as in the above formula (5). Specifically, in the relational expression, one is obtained for the first sensor, and one for the second sensor, and two for the one wind turbine blade 10. Relationship. For example, in the case of the first sensor, the above relation, by lines (5 ') of the following formula and performance.

M _HP-LP = a(ε _A1 -ε _A3 )×10 ^-6 +b [Nm] (5) '

In the formula (5), ε _A1 is the deformation at the position of the sensor A1 calculated according to (2) ' , and ε _A3 is calculated at the position of the sensor A3 according to the same formula. The deformation.

Here, if the difference ε _A1 - ε _A3 of the deformation of the flap direction (the direction of HP-LP in FIG. 4) of the above (5) ' is taken as the horizontal axis, and M _{HP-LP is taken} as the vertical axis, A chart is obtained as shown in Figure 9. In this way, if the relationship between the deformation ε _{A1 to A4} and the information on the load at the root of the fan is graphed, the intercept and slope of the graph can be derived, and the coefficient a in the above (5) ' can be calculated. (slope) and coefficient b (intercept). The combination of the coefficients a and b at one wind turbine blade 10 is calculated to have two of the flap direction and the edge direction, respectively.

Then, by performing the processing from the measurement of the sensor until the calculation of the coefficient, the complex coefficient is obtained, and the corrected functional formula is obtained by using the average value of the coefficients. For example, by discarding the maximum value and the minimum value, it is possible to remove bursty data such as noise. In addition, even if the data other than the noise is removed, the calculation of the average value will not be affected.

Then, in this way, after obtaining the relational expression with high reliability (in other words, after obtaining the corrected relational expression), the load calculating unit 32 uses the relational expression and measures data from each sensor. The load at the root of the fan blade 10 is calculated. As a result, it is possible to calculate the load with a high reliability.

Further, in the present embodiment, the data used in the region which is not the region A of FIG. 6 among the measurement data measured by the respective sensors A1 to A6 is used, but this is for correction. Accuracy is improved. Specifically, in order to obtain the above-described coefficients a and b, the momentum obtained when there is no wind (the ideal momentum when the correction is performed) is approximated. Hereinafter, the description will be made more specifically using FIGS. 11A, B and FIGS. 12A and B.

Fig. 11A shows the momentum of the flap direction when the horizontal axis shows the direction of the flap in the absence of wind, and the direction of the flap in the case where the vertical axis shows the wind speed of 8 meters. Figure 11B is a comparison of the momentum in the edge direction. 11A and FIG. 11B are functions obtained when the coefficients a and b are extracted by the measurement data including the region A of FIG. 6, and are compared with the ideal windless data. If it is assumed that the ideal windless function is y=x, and the coefficient a and b are calculated using the measurement data including the region A, the ratio is y=0.9701x-31.88. Further, if the momentum at the time of no wind is compared with the momentum calculated from the measurement data including the area A, there are many points which are shifted from the straight line of y=x. By this, it is represented that the load obtained by using the coefficients a and b calculated by the measurement data of the area A becomes larger than the load when there is no wind.

On the other hand, FIG. 12A and FIG. 12B are similar to FIGS. 11A and 11B, and show the momentum when there is no wind on the horizontal axis and the momentum when the wind speed is 8 meters on the vertical axis. A graph in which the coefficients a and b are calculated by measuring the measurement data excluding the measurement data obtained in the area A of Fig. 6 . For example, as shown in FIG. 12A, when the coefficients a and b are calculated using the measurement data not including the area A, it is y=0.9968x-3.322. Further, as a result of the load obtained thereby, it can be seen from the graph that the momentum when the wind is no wind and the wind speed is 8 meters. As a result, the coefficients are corrected by the coefficients a and b obtained by not including the measurement data of the area A, whereby the load can be made closer to the windless.

In addition, when the measurement data by the sensor is obtained, it is assumed that the wind turbine blade 10 is rotated once at least from the azimuth angle of 0 degrees to 180 degrees, and it is assumed that the wind turbine blade 10 is rotated by 180 degrees. The rotation of the degree generates one data file for correction, but the number of rotations of the azimuth is not particularly limited. Further, in the present embodiment, it is configured to generate one data file for correction by 360 degrees of rotation.

More specifically, the rotor system begins to idle by moving the tilt angle from 109 degrees to 60 degrees or from 60 degrees to 109 degrees. Here, by moving the inclination angle from 109 degrees to 60 degrees, the rotor is rotated at least by one, and one data file is acquired. Similarly, the rotor is rotated by at least 1 by moving the tilt angle from 60 degrees to 109 degrees, and one data file is acquired.

In other words, in the present embodiment, when the inclination angle is directed toward the windward side in the range in which the influence of the air force is removed, one correction is obtained by at least rotating the rotor by one. Use the data file. Similarly, when the tilt angle is moved toward the feather side, one calibration data file is acquired.

In the present embodiment, ten calibration data files are acquired by performing the above-described general tilting operation.

Further, when the data for the 10th correction (that is, the coefficients a and b) is calculated, it is desirable to review the reliability of the coefficients a and b by calculating the average values. .

Further, the X system represents the data for calibration (18 points for measurement data without load, 12 points for correction data (data for edge direction of each wind turbine blade 10 and flap direction), and N system for tilt angle of 109 degrees) The number of times the action becomes 60 degrees and then becomes 109 degrees (one cycle). Also, m is taken as an average value. In addition, in this case, the maximum and minimum data are omitted from the 2N calibration data files, and the average of 2 (N-1) is obtained. Then, it is reviewed whether the average value of the correction values a and b satisfies the following range conditions. When the reference value is satisfied, the average value of the calibration data is used as the field parameter.

[Expression 3]

[average value]

[Review of benchmark values]

1.7×10 ⁹ <a<2.7×10 ⁹ (9)

-100kNm<b<100kNm (10)

As described above, the measurement data is acquired via a sensor provided at the wind turbine blade 10, and the deformation and load of the wind turbine blade 10 are calculated based on the acquired data. The function included in the load calculating unit 20 is corrected by a coefficient of a new function obtained by the relationship between the deformation of the wind turbine blade 10 and the load calculated based on the measurement data. Thereby, since a new function can be easily calculated from the measurement data, the coefficient for correction can be easily determined.

Further, in the measurement data used at this time, the measurement data of the sensor obtained in the range of the inclination angle of the wind turbine blade 10 having the deviation between the maximum value and the minimum value of the air force torque is used, and The measurement data capable of ignoring the influence of the air force torque is used, and therefore, the accuracy of the correction can be improved.

Moreover, by calculating the deformation of the sensor itself and setting OFFSET, the accuracy of the correction can be further improved. Further, when the measurement data is acquired, the inclination angle range of the wind turbine blade 10 (for example, in the range of the inclination angle of 60 to 109 degrees) is set to a specific value or less between the maximum value and the minimum value of the air force torque. The obtained measurement data can be used without specifically limiting the azimuth. Therefore, it is possible to use a wide range of measurement data for correction.

Further, since the calculation of the acquisition of the measurement data, the calculation of the load and the deformation, and the evaluation of the reliability of the calibration data are performed by the load measuring device 100, the time taken for the calibration operation can be shortened. It is also possible to reduce the burden imposed on the user.

Further, in the above-described embodiment, the load measuring device is premised on the processing by the hard body, but it is not necessarily limited to such a configuration. For example, it may be configured to be processed by software based on the output signals from the respective sensors. In this case, the load measuring device includes a main memory device such as a CPU or a RAM, and a computer-readable recording medium on which a program for recording all or part of the above-described processing is recorded. Then, the CPU reads out the program recorded on the above-mentioned memory medium, and performs processing and calculation processing of information, thereby realizing the same processing as the above-described load measuring device.

Here, the computer-readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be sent to the computer via a communication line, and the computer that receives the transmission may be executed to execute the program.

[Modification]

Further, in the load measuring device 100 of the present embodiment, the sensor is obtained in a range of inclination angles of the wind turbine blade 10 based on a variation between the maximum value and the minimum value of the torque torque of the air force being a specific value or less. The measurement data is used to correct the above function, but it is not limited to this. For example, instead of the range of the inclination angle, the range of the number of rotations of the wind turbine blade 10 may be set, and the range of the number of rotations of the wind turbine blade may be a specific value or less depending on the deviation between the maximum value and the minimum value of the torque torque due to the wind speed. The information of the sensor obtained is used to correct the function.

In the wind turbine generator 1 of the present embodiment, the number of the plurality of wind turbine blades 10 is set to three, but the number of the wind turbine blades 10 is not particularly limited.

Further, in the load measuring device 100 of the present embodiment, six sensors are attached to one wind turbine blade 10, but the number of the sensors is not particularly limited.

Further, in the load measuring device 100 of the present embodiment, the table 31 is calculated from the azimuth angle and the tilt angle, but is not limited thereto. For example, the table may be given to the correction unit 30 in advance.

[Second Embodiment]

Next, a second embodiment of the present invention will be described.

The load measuring device according to the present embodiment differs from the first embodiment in that the angle data of the azimuth angle and the tilt angle is limited to a specific value, and the wind speed is limited to a range in which the negative air force torque is small. The point at which the information is obtained. In the following description, the load measuring device according to the present embodiment will be described in common with the first embodiment, and the description thereof will be omitted.

When the wind speed is 3 meters or less, the sensor 7 is formed at two points formed by the first azimuth angle and the second azimuth angle rotated by 180 degrees from the first azimuth angle. The inclination is set to be measured for the minimum inclination angle and the maximum inclination angle.

More specifically, the sensor acquires a position where the azimuth angle of the wind turbine blade 10 is at a position of 90 degrees and 270 degrees when the wind speed is 3 meters or less, and the inclination angle is the same in each azimuth angle. Measurement data when the conditions are set to 21 degrees and 109 degrees.

When the data of one of the wind turbine blades 10 is being measured, the inclination angles of the other two wind turbine blades 10 are set to, for example, 85 degrees, and the air is turned into an idling state.

By using the data measured from the two locations at the position where the azimuth angle is rotated by 180 degrees, the measurement data used in the function calculated by the parameter calculation unit 34 is enabled. A wide range of data is obtained for the horizontal axis. Thereby, the accuracy in the case of calculating the coefficients a and b by less measurement data can be improved. Further, since the parameters can be calculated from a small amount of measurement data, the time taken for the correction can be shortened.

The embodiments of the present invention are described in detail below with reference to the drawings. However, the specific configuration is not limited to the embodiments, and includes design changes made without departing from the gist of the present invention. Wait.

1. . . Wind power generator

7. . . Sensor

20. . . Load calculation unit

30. . . Correction department

31. . . table

32. . . Load acquisition department

33. . . Deformation calculation unit

34. . . Parameter calculation unit

100. . . Load measuring device

Fig. 1 is a view showing a schematic configuration of the entire wind turbine generator according to the first embodiment of the present invention.

[Fig. 2] A diagram for explaining the root of a fan.

Fig. 3 is an example of a cross-sectional view at a position of a distance of 1.8 m from the root of the blade of the wind turbine blade.

[Fig. 4] A diagram for explaining the arrangement of the sensor position seen from the root of the blade.

Fig. 5 is a block diagram showing a schematic configuration of a load measuring device according to a first embodiment of the present invention.

[Fig. 6] A graph showing the relationship between the air force torque at each wind speed, the number of revolutions of the generator, and the inclination angle.

FIG. 7 is a view showing an example of a table included in the correction unit.

[Fig. 8] A diagram for explaining an azimuth angle.

FIG. 9 is a view showing an example of the relationship between the deformation and the load according to the measurement data.

Fig. 10 is a view showing an example of the relationship between the load at the root of the blade and the wavelength of the deformation.

[Fig. 11A] shows the load (flap direction) and the absence of wind when the correction is performed when the wind speed is 8 meters per second including the measurement data of the inclination angle at the range of the area A. A diagram of one of the examples of load comparison.

[Fig. 11B] shows the load (edge direction) compared with the load when there is no wind when the correction is performed when the wind speed is 8 meters per second including the measurement data of the inclination angle at the range of the area A. One of the figures.

[Fig. 12A] shows the load (the flap direction) and the load when there is no wind when the wind speed is 8 meters per second, which does not include the measurement data of the inclination angle at the range of the area A. A diagram of one of the comparisons.

[Fig. 12B] shows the load (edge direction) and the load at the time of no wind when the wind speed is 8 meters per second, which does not include the measurement data of the inclination angle at the range of the area A. A comparison of one of the figures.

7. . . Sensor

20. . . Load calculation unit

30. . . Correction department

31. . . table

32. . . Load acquisition department

33. . . Deformation calculation unit

34. . . Parameter calculation unit

100. . . Load measuring device

Claims (11)

A load measuring device is a load measuring device applied to a windmill in which a pitch angle of a wind turbine blade is set to be variable, and is characterized in that: a sensor is provided for taking out the wind turbine blade The deformation and the load calculation means are provided with a function of expressing the relationship between the deformation of the wind turbine blade and the load of the wind turbine blade, and by using deformation of the measurement data according to the sensor in the function. The load of the wind turbine blade is taken out; and the correction means is based on the inclination range and the rotation number range of the wind turbine blade when the deviation between the maximum value and the minimum value of the air force torque due to the wind speed is equal to or less than a specific value. The measured data of the aforementioned sensor is obtained to correct the function. The load measuring device according to the first aspect of the invention, wherein the correction means is based on the range of the inclination angle range and the number of rotations of the wind turbine blade whose air force torque is equal to or less than a specific value. The measurement data of the detector is used to correct the aforementioned function. The load measuring device according to the first or second aspect of the invention, wherein the correction means includes: a table, a load of the wind turbine blade when the wind is not present, and a tilt angle of the wind turbine blade Further, the azimuth angle is additionally related; and the load obtaining means obtains the inclination angle of the wind turbine blade corresponding to the measurement data obtained by the sensor from the table and And a deformation calculating means for calculating a deformation of the wind turbine blade from a measurement data of the sensor; and a parameter calculation means for the wind turbine blade obtained by the load acquisition means The load is corrected by the relationship between the load and the deformation calculated by the deformation calculating means. The load measuring device according to claim 3, wherein the correction means obtains the load based on the load of the wind turbine blade obtained by the load acquiring means and the measurement data of the sensor. The measurement data of the aforementioned sensor at the time of load, and using the measurement data when there is no load, the OFFSET correction is performed on the measurement data of the aforementioned sensor. The load measuring device according to the first or second aspect of the invention, wherein the sensor includes a pair of first sensors that are disposed to hold the wind turbine blade and are opposite to each other The position and the pair of second sensors are disposed at positions different from the first sensor and held at the position opposite to the wind turbine blade. The load measuring device according to the first or second aspect of the invention, wherein the sensor includes a pair of third sensors that are disposed to hold the wind turbine blade and are opposite to each other a position different from the first sensor and the second sensor, and being disposed in parallel with any of the first sensor or the second sensor Location. A load measuring device is a load measuring device applied to a windmill in which a pitch angle of a wind turbine blade is set to be variable, and is characterized in that: a sensor is provided for taking out the wind turbine blade The deformation and the load calculation means are provided with a function of expressing the relationship between the deformation of the wind turbine blade and the load of the wind turbine blade, and by using deformation of the measurement data according to the sensor in the function. Obtaining a load of the wind turbine blade; and correcting means, when the wind speed is 3 meters or less, according to the second azimuth angle rotated by 180 degrees by the first azimuth angle and the first azimuth angle The function is corrected at the two locations where the inclination is set to the measurement data of each of the aforementioned sensors at the minimum inclination angle and the maximum inclination angle. A load measuring method is a load measuring method applied to a windmill in which a pitch angle of a windmill blade is set to be variable, and is characterized in that: the deformation of the wind turbine blade is taken out; and the deformation of the wind turbine blade is provided Calculating the relationship between the load of the windmill blade and the load of the windmill blade by using the deformation of the measured data according to the sensor in the function; according to the wind speed The function of the sensor is obtained by correcting the measurement data of the sensor obtained by the inclination angle range and the rotation number range of the wind turbine blade when the deviation between the maximum value and the minimum value of the air force torque is equal to or less than a specific value. A load measuring program product is a load measuring program product applicable to a windmill in which a pitch angle of a windmill blade is set to be variable, wherein the load measuring program product is used to cause a computer to implement the following Processing: The first processing is provided with a function of expressing the relationship between the deformation of the wind turbine blade and the load of the wind turbine blade, and by using the deformation of the measurement data according to the sensor in the function, The load of the wind turbine blade is taken out; and the second process is performed according to the inclination range and the rotation number range of the wind turbine blade when the deviation between the maximum value and the minimum value of the air force torque due to the wind speed is equal to or less than a specific value. The measured data of the aforementioned sensor is obtained to correct the function. A load measuring method is a load measuring method applied to a windmill in which a pitch angle of a wind turbine blade is set to be variable, and is characterized in that: a deformation between the wind turbine blade and a load of the wind turbine blade is provided The relationship is a function of performance, and the load of the wind turbine blade is taken out by using the deformation of the measurement data according to the sensor in the function; when the wind speed is 3 meters or less, according to the first The azimuth angle and the measurement data of each of the sensors when the inclination angle is set to the minimum inclination angle and the maximum inclination angle at two points formed by the second azimuth angle rotated by 180 degrees from the first azimuth angle, This function is corrected. A load measuring program product is a load measuring program applied to a windmill in which a pitch angle of a windmill blade is set to be variable. The product is characterized in that the load measuring program product is configured to cause the computer to perform the following processing: the first processing is provided with a function of expressing the relationship between the deformation of the wind turbine blade and the load of the wind turbine blade. And the load of the wind turbine blade is taken out by using the deformation of the measurement data according to the sensor in the function; and the second processing is performed when the wind speed is 3 meters or less. The azimuth angle and the measurement data of each of the sensors when the inclination angle is set to the minimum inclination angle and the maximum inclination angle at two points formed by the second azimuth angle rotated by 180 degrees from the first azimuth angle, This function is corrected.