Displacement observation system for wind turbine generator and displacement observation method for wind turbine generator

Abstract

To accurately measure displacement of a tower top part regardless of rotation operation of a nacelle arranged on an upper part of the tower top part.SOLUTION: This system is provided with a base station 30, observation stations 11-13 arranging a plurality of GNSS antennas 11a-13a on the upper part of a nacelle respectively, and a displacement observation device 40 measuring the displacement of a tower top part based on observation data from the reference station 30 and the observation stations 11-13, and the displacement observation device 40 is provided with an initial setting part 41 measuring the position of each GNSS antenna 11a-13a while rotating the nacelle 3 and setting the center of a circle which is the history of the position of each GNSS antenna 11a-13a as the initial position of the tower top part and calculating the horizontal displacement from the initial position of the tower top part, and a displacement measuring part 42 measuring the position of each GNSS antenna 11a-13a and calculating the intersection position on the initial position side of the circle drawn by using each radius as the present position of the tower top part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a displacement observation system for a wind turbine generator and a displacement observation method for a wind turbine generator that can measure the displacement of the tower top with high accuracy despite the rotational movement of a nacelle arranged above the tower top. [Background technology]

[0002] GNSS (Global Navigation Satellite System) positioning measures position by receiving satellite signals from four or more positioning satellites. Standalone positioning using a single GNSS antenna is susceptible to the effects of positioning errors and delays in satellite signals from the positioning satellites, and can only measure position with an accuracy of about 10 meters. On the other hand, relative positioning using a reference station whose positions are known in advance and an observation station installed at the desired location can determine the relative positional relationship between two points with an accuracy of about one part in a million (1 cm over 10 km) by measuring the time difference between the arrival of each satellite signal at each GNSS antenna (see Patent Document 1). This relative positioning method, for example, uses interferometric positioning using the RTK (Real Time Kinematic)-GNSS method, which uses carrier phase.

[0003] This GNSS-based relative positioning is used in a variety of situations, including observing slope dynamics, detecting the shaking of high-rise buildings due to long-period seismic motion, and determining the positions of people and moving objects. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-191093 Summary of the Invention [Problem to be solved by the invention]

[0005] In wind power generation equipment using horizontal axis wind turbines, in order to improve power generation efficiency, azimuth control known as yaw control is performed, in which the nacelle 3 installed at the top of the tower 2 is rotated in the circumferential direction of the tower 2, and the rotation plane (rotor plane) of the wind turbine blades 4 is aligned directly with the wind direction (see Figure 1).

[0006] In conventional displacement measurements using GNSS positioning, the position coordinates at the time the observation station was installed are assumed to be the initial position (zero displacement point), and the difference between the position coordinates of the initial position and the current position is measured as displacement. However, when applied to measuring displacement at the top of the tower of a wind turbine generator, the observation station is installed on the nacelle 3, but the nacelle 3 faces in one direction, making it impossible to identify the zero displacement point at the top of the tower. In addition, because the nacelle 3 moves according to the wind direction, there is an issue in that it is impossible to distinguish whether the obtained positioning data is due to displacement of the tower top or a change in the orientation of the nacelle 3.

[0007] Although there would be no problem if the GNSS antenna could be installed at a single point at the center of rotation of the nacelle 3 installed at the top of the tower, it is difficult to place the GNSS antenna at the center of rotation of the nacelle 3 due to the structure and maintenance of the wind turbine generator.

[0008] The present invention has been made in consideration of the above, and aims to provide a displacement observation system for a wind turbine generator and a displacement observation method for a wind turbine generator that can accurately measure the displacement of the tower top despite the rotational movement of a nacelle located above the tower top. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the object, the displacement observation system for a wind turbine generator according to the present invention is a wind turbine generator displacement observation system that observes at least the displacement of the tower top of a wind turbine generator in which a nacelle that performs yaw control to orient the rotor face directly in the wind direction is mounted on the top of the tower, and includes: a reference station whose position is known and that receives satellite signals from a plurality of positioning satellites; a plurality of observation stations corresponding to each GNSS antenna, each of which is arranged on the top of the nacelle and receives satellite signals from the plurality of positioning satellites; and a displacement observation device that measures the displacement of the tower top based on observation data from the reference station and each observation station. the displacement observation device comprises an initial setting unit that measures the position of each GNSS antenna while rotating the nacelle, sets the center of a circle formed by the position history of each GNSS antenna as the center of rotation of the nacelle, sets the center of rotation of the nacelle to an initial position of the tower top, and calculates the radius of each circle; and a displacement measurement unit that measures the position of each GNSS antenna, calculates the intersection position on the initial position side of circles drawn from the measured positions using the radii corresponding to each GNSS antenna as the current position of the tower top, and measures the horizontal displacement of the tower top based on the initial position and current position of the tower top.

[0010] Furthermore, in the displacement observation system for a wind turbine generator according to the present invention, in the above invention, the initial setting unit further determines an initial nacelle orientation of the nacelle, and the displacement measurement unit, after measuring the horizontal displacement, determines a current nacelle orientation relative to the initial nacelle orientation and measures the rotational displacement of the nacelle.

[0011] In addition, the displacement observation system for a wind turbine generator according to the present invention is characterized in that, in the above invention, the GNSS antennas installed on the nacelle are arranged at least 1 m apart and are arranged at a distance from the rotor surface formed by the blades.

[0012] The displacement observation method for a wind turbine generator according to the present invention is a method for observing at least the displacement of a tower top of a wind turbine generator in which a nacelle that performs yaw control to orient a rotor surface directly toward the wind direction is mounted on the top of the tower, and the displacement observation device measures the displacement of the tower top based on observation data from a reference station whose position is known and that receives satellite signals from a plurality of positioning satellites, and a plurality of observation stations corresponding to each GNSS antenna that are arranged on the top of the nacelle and receive satellite signals from the plurality of positioning satellites. The method includes an initial setting step of measuring the position of each GNSS antenna, setting the center of a circle formed by the position history of each GNSS antenna as the center of rotation of the nacelle, setting the center of rotation of the nacelle to an initial position of the tower top, and calculating the radius of each circle; and a displacement measurement step of measuring the position of each GNSS antenna, calculating the intersection position on the initial position side of circles drawn from the measured positions using the radii corresponding to each GNSS antenna as the current position of the tower top, and measuring the horizontal displacement of the tower top based on the initial position and current position of the tower top.

[0013] Furthermore, in the displacement observation method for a wind turbine generator according to the present invention, in the above invention, the initial setting step further determines an initial nacelle orientation of the nacelle, and the displacement measurement step, after measuring the horizontal displacement, determines a current nacelle orientation relative to the initial nacelle orientation and measures the rotational displacement of the nacelle. [Effects of the Invention]

[0014] According to the present invention, the displacement of the tower top can be measured with high accuracy despite the rotational movement of the nacelle arranged above the tower top. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating the general configuration of a wind turbine generator and yaw control according to this embodiment. [Figure 2] FIG. 2 is a plan view of the wind turbine generator. [Figure 3] FIG. 3 is a diagram showing a schematic configuration of a displacement observation system for a wind power plant according to this embodiment. [Figure 4] FIG. 4 is a diagram showing the locus of the positions of the GNSS antennas as the nacelle rotates. [Figure 5] FIG. 5 is a diagram showing the position of each GNSS antenna using coordinates, with the center of rotation of the nacelle being the zero displacement point of the top of the antenna. [Figure 6] FIG. 6 is a diagram illustrating the process of measuring the horizontal displacement of the tower top. [Figure 7] FIG. 7 is a flowchart showing the procedure of the displacement observation process performed by the displacement observation device. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0017] <Configuration> Fig. 1 is a diagram illustrating the general configuration and yaw control of a wind turbine generator 1 according to this embodiment. Fig. 2 is a plan view of the wind turbine generator 1. Fig. 3 is a diagram illustrating the general configuration of a displacement observation system for the wind turbine generator 1 according to this embodiment.

[0018] As shown in Figure 1, the wind turbine generator 1 rotates a nacelle 3 installed at the top of the tower 2 in the circumferential direction of the tower 2, and performs azimuth control called yaw control, in which the rotation plane (rotor surface 4a) of the wind turbine blades 4 is aligned directly with the wind direction, thereby improving power generation efficiency.

[0019] 2, multiple GNSS antennas 11a to 13a are installed on top of the nacelle 3. The GNSS antennas 11a to 13a are preferably spaced apart by 1 m or more and installed at positions away from the rotor surface 4a to prevent noise from being introduced due to satellite signal blocking by the blades 4 as the rotor rotates.

[0020] 3, the displacement observation system for the wind turbine generator 1 includes a reference station 30 having a known position and a GNSS antenna 30a that receives satellite signals from four or more positioning satellites S in a positioning satellite constellation 20, a wind turbine generator 1 having an observation station group 10 having a plurality of observation stations 11-13 corresponding to a plurality of GNSS antennas 11a-13a that receive satellite signals from the four or more positioning satellites S, and a displacement observation device 40 that measures the displacement of the tower top of the wind turbine generator 1 based on observation data from the reference station 30 and the observation stations 11-13. The displacement observation device 40 may be installed within the wind turbine generator 1 or at a remote location. Furthermore, the reference station 30 and the wind turbine generator 1 may be connected to a server corresponding to the displacement observation device 40 via a network.

[0021] In this embodiment, since the displacement of the tower top is on the order of several tens of centimeters, the displacement is measured using relative positioning. Reference station 30 is installed within a 10 km radius of observation stations 11-13.

[0022] The displacement observation device 40 has an initial setting unit 41, a displacement measurement unit 42, and an output unit 43. The initial setting unit 41 measures the position of each of the GNSS antennas 11a to 13a while rotating the nacelle 3, sets the center of a circle formed by the position history of each of the GNSS antennas 11a to 13a as the rotation center of the nacelle 3, sets the rotation center of the nacelle 3 to an initial position at the top of the tower, and calculates the radius of each circle.

[0023] The displacement measurement unit 42 measures the position of each of the GNSS antennas 11a to 13a, determines the intersection position on the initial position side of a circle drawn from the measured position using the radii corresponding to each of the GNSS antennas 11a to 13a, and measures the horizontal displacement of the tower top based on the initial position and current position of the tower top.

[0024] In this embodiment, the initial setting unit 41 further determines the initial nacelle orientation of the nacelle 33, and the displacement measurement unit 42 measures the horizontal displacement, then determines the current nacelle orientation relative to the initial nacelle orientation, and measures the rotational displacement of the nacelle 33, so that the correspondence between the horizontal displacement and the rotational displacement can also be grasped.

[0025] The output unit 43 outputs the horizontal displacement and rotational displacement measured by the displacement measuring unit 42 to a display unit or storage unit (not shown), or to an external display device or storage device.

[0026] <Initial settings> The initial setting by the initial setting unit 41 is performed when the wind is weak and the wind turbine rotor is not rotating, i.e., when the wind turbine's cut-in wind speed is below 3 to 4 m / s at the wind turbine hub height. As shown in FIG. 2, the nacelle 3 is rotated 360° and the position coordinates of each GNSS antenna 11a to 13a of each observation station 11 to 13 are measured using GNSS relative positioning. Then, as shown in FIG. 4, the coordinates measured by each GNSS antenna 11a to 13a form a circle centered on the center of the tower 2. In FIG. 4, the distances from the center of rotation of the nacelle 3 to the GNSS antennas 11a and 12a are the same, and the measurement positions of the GNSS antennas 11a and 12a overlap. The center of each circle is obtained by calculating the intersection coordinates of the perpendicular bisectors of each circle. The center coordinates (latitude and longitude coordinates) of this circle are the center of rotation of the nacelle 3 and are set as the initial position of the tower top (zero displacement point C: (x0, y0)).

[0027] Additionally, an arbitrary nacelle orientation (the direction in which the rotor plane 4a faces) is determined as the initial nacelle orientation (rotation angle θ = 0°). Note that FIG. 5 is shown in a polar coordinate system in which the rotation angle θ is clockwise relative to the zero displacement point (x0, y0). As a result, as shown in FIG. 5, the initial positions of each GNSS antenna 11a to 13a at the time of initial setup can be expressed as position coordinates (x1, y1), (x2, y2), and (x3, y3), respectively. Note that at this time, the distances from the zero displacement point to each of the GNSS antennas 11a to 13a, i.e., the radii r1 to r3 of each circle, are calculated in advance.

[0028] The initial nacelle orientation can be obtained from yaw control information, but if yaw control information is not available, the GNSS antennas 11a to 13a may be installed by utilizing the structural symmetry of the secondary members installed on the nacelle 3, and the initial nacelle orientation may be estimated from the relative positions of the GNSS antennas 11a to 13a.

[0029] <Displacement measurement> FIG. 6 is a diagram illustrating the process of measuring the horizontal displacement of the tower top. As shown in FIG. 6, when the rotational displacement of the nacelle 3 is θ1 and the horizontal displacement of the tower top is A1, the position coordinates of the displaced GNSS antennas 11a′ to 13a′ are (x11, y11), (x21, y21), and (x31, y31), respectively. In this case, the zero displacement point C (x0, y0) displaces from the position coordinates (x0, y0) to the displacement point C′ (x01, y01). This displacement point C′ is found as the intersection position on the side of the zero displacement point C of a circle with a radius r1 centered at the position coordinates (x11, y11), a circle with a radius r2 centered at the position coordinates (x21, y21), and a circle with a radius r3 centered at the position coordinates (x31, y31). Note that when the displacement A1 is zero, the displacement point C′ coincides with the zero displacement point C.

[0030] On the other hand, the rotational displacement θ1 can be calculated, for example, as the angle between a radial line from the displacement zero point C passing through the position coordinates (x1, y1) and a radial line from the displacement zero point C passing through the position coordinates (x11, y11) moved back by the horizontal displacement.

[0031] <Displacement observation processing using a displacement observation device> Fig. 7 is a flowchart showing the displacement observation processing procedure performed by the displacement observation device 40. As shown in Fig. 7, first, the initial setting unit 41 performs initial setting processing (step S101). That is, the center of a circle formed by the positions of each GNSS antenna acquired while rotating the nacelle 3 is set to the origin position (zero displacement point C) at the top of the tower, the radius between the origin position and each GNSS antenna position is acquired, and the initial nacelle orientation is then determined.

[0032] Thereafter, the displacement measurement unit 42 performs a position measurement process for each GNSS antenna (step S102), and further performs a displacement measurement process for determining the horizontal displacement and the displacement of the nacelle orientation from the measured position of each GNSS antenna (step S103).

[0033] Thereafter, the output unit 43 performs processing to output the measured horizontal displacement and displacement in the nacelle orientation to a display unit, a storage unit, etc. (step S104). Thereafter, it is determined whether or not an instruction to end this processing has been given (step S105), and if the processing has not ended (step S105, No), the process proceeds to step S102 to continue the displacement measurement processing described above, and if the processing has ended (step S105, Yes), the process ends.

[0034] Note that the above displacement measurements are premised on the assumption that the deformation of the nacelle 3 itself and the displacement of the GNSS antenna installation members are sufficiently small compared to the displacement of the tower top and can be ignored. In other words, the nacelle 3 is assumed to be a rigid body.

[0035] Furthermore, when the top of the tower displaces horizontally due to external disturbances such as wind, it actually describes an arc centered on the tower base, but with the exception of small wind turbines, the tower length is several tens of meters, while the horizontal displacement of the tower top is on the order of several tens of centimeters, so the vertical displacement accompanying the horizontal displacement is assumed to be negligible.In other words, it is assumed that the coordinates of the GNSS antenna are affected only by the translation of the tower top in the X and Y directions due to external disturbances such as wind, and the rotation around the Z axis (vertical axis) due to yaw control of the nacelle 3.

[0036] Based on these assumptions, there are two degrees of freedom: radius r and rotation angle θ, so the observation station group 10 can determine the horizontal displacement of the tower top and the displacement of the nacelle orientation with the measurement values ​​of at least two GNSS antennas. Note that by installing GNSS antennas on the wind turbine tower or foundation, it becomes possible to monitor the condition in four dimensions, including height and time.

[0037] In this embodiment, the horizontal displacement of the tower top can be measured by the GNSS antenna placed on the nacelle 3, regardless of the rotation of the nacelle 3, making it possible to monitor the safety of the entire wind turbine-foundation system during earthquakes and typhoons. Also, because the wind turbine has a cantilevered tower, if the displacement of the nacelle 3 can be measured, the bending moment of the tower 2 can be easily calculated, which can be used for design verification, determining appropriate maintenance times, predicting remaining life, etc.

[0038] Note that the configurations illustrated in the above embodiments are merely functional schematics and are not necessarily physically configured as shown. In other words, the distribution and integration of each device and component is not limited to that illustrated, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various usage situations, etc. [Explanation of symbols]

[0039] 1. Wind power generation equipment 2. Tower 3 Nacelle 4 blades 4a Rotor surface 10 observation stations 11~13 Observation Stations 11a~13a, 30a GNSS antenna 20 positioning satellites 30 Reference station 40 Displacement observation device 41 Initial setting section 42 Displacement measurement unit 43 Output section C Zero displacement point C´ displacement point S positioning satellite

Claims

1. A displacement observation system for a wind turbine generator, which observes at least the displacement of a tower top of a wind turbine generator, the system comprising: a nacelle mounted on the tower top, which performs yaw control to orient a rotor surface directly toward the wind direction; a reference station having a known position that receives satellite signals from a plurality of positioning satellites; a plurality of observation stations corresponding to the GNSS antennas, each of which receives satellite signals from a plurality of positioning satellites and is disposed on the top of the nacelle; a displacement observation device that measures the displacement of the tower top based on observation data from the reference station and each observation station; Equipped with The displacement observation device is an initial setting unit that measures the position of each GNSS antenna while rotating the nacelle, sets the center of a circle formed by the position history of each GNSS antenna as the rotation center of the nacelle, sets the rotation center of the nacelle to an initial position of the top of the tower, and calculates the radius of each circle; a displacement measurement unit that measures the position of each GNSS antenna, determines the intersection position on the initial position side of a circle drawn from the measured position using each radius corresponding to each GNSS antenna, and measures the horizontal displacement of the tower top based on the initial position and current position of the tower top; A displacement observation system for a wind power generation device, comprising:

2. The initial setting unit further determines an initial nacelle orientation of the nacelle, 2. The displacement observation system for a wind turbine generator according to claim 1, wherein the displacement measurement unit, after measuring the horizontal displacement, determines a current nacelle orientation relative to the initial nacelle orientation and measures a rotational displacement of the nacelle.

3. 3. A displacement observation system for a wind turbine generator as described in claim 1 or 2, characterized in that each GNSS antenna installed on the nacelle is positioned at a distance of at least 1 m and away from the rotor plane formed by the blades.

4. A method for observing displacement of a wind turbine generator, the method comprising: observing at least the displacement of a tower top of a wind turbine generator in which a nacelle that performs yaw control to orient a rotor face directly toward the wind direction is mounted on the tower top; a displacement observation device that measures the displacement of the tower top based on observation data from a reference station whose position is known and that receives satellite signals from a plurality of positioning satellites, and a plurality of observation stations that correspond to each GNSS antenna, the plurality of GNSS antennas being arranged on the top of the nacelle and that receive satellite signals from the plurality of positioning satellites; an initial setting step of measuring the positions of each GNSS antenna while rotating the nacelle, setting the center of a circle formed by the position history of each GNSS antenna as the rotation center of the nacelle, setting the rotation center of the nacelle to an initial position of the top of the tower, and calculating the radius of each circle; a displacement measurement step of measuring the position of each GNSS antenna, determining the intersection position on the initial position side of a circle drawn from the measured position using each radius corresponding to each GNSS antenna as the current position of the tower top, and measuring the horizontal displacement of the tower top based on the initial position and current position of the tower top; A method for observing displacement of a wind turbine generator, comprising:

5. The initial setting step further includes determining an initial nacelle orientation of the nacelle; 5. The displacement observation method for a wind turbine generator according to claim 4, wherein the displacement measuring step includes, after measuring the horizontal displacement, determining a current nacelle orientation relative to the initial nacelle orientation and measuring a rotational displacement of the nacelle.

Images