Load measurement system, damage rate estimation system, life prediction system, load measurement method, damage rate monitoring method and program

Abstract

This measures how much load is being applied to each tooth of the ring gear. [Solution] The load measurement system comprises a load detection unit that detects the applied load on the teeth of a wind turbine when the driving force of the drive unit or an external force is applied to the teeth of the ring gear by means of the pinion being driven through the pinion while the ring gear is engaged with the pinion, and a position identification unit that identifies the target tooth on which the applied load is applied from among the multiple teeth of the ring gear.

Description

Technical Field

[0001] The present invention relates to a load measurement system, a damage rate estimation system, a life prediction system, a load measurement method, a damage rate monitoring method, and a program.

Background Art

[0002] Conventionally, in order to enable power generation using wind power by a wind power generation device and to improve the efficiency of power generation, it is known to provide a movable part in the wind power generation device. For example, a wind power generation device having a yaw control function for adjusting the direction of a nacelle according to the wind direction is known. Such a wind power generation device is provided with a movable part that enables yaw control. This type of wind power generation device is known, for example, from the technology described in Patent Document 1. The wind power generation device described in Patent Document 1 is installed on the ground or at sea, and has a tower that serves as a support column for a generator, a nacelle provided on the tower and incorporating the generator, and a rotor composed of a hub and blades provided at one end of the nacelle and converting wind into rotational energy. In this wind power generation device, the movable part that enables yaw control has a yaw ring gear fixed to the tower and pinions of a plurality of yaw actuators provided on the nacelle. This wind power generation device performs yaw control to control the positions of the nacelle and the rotor with respect to the tower by driving the yaw actuator in a state where the yaw ring gear meshes with the pinion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the movable part of a wind turbine having a ring gear and a drive mechanism with a pinion, when the ring gear is meshed with the pinion, a load may be applied to the teeth of the ring gear via the pinion. If a load is applied to the teeth of the ring gear over a certain period of time, those teeth of the ring gear may be damaged. Therefore, it was necessary to measure which teeth of the ring gear were being subjected to what extent and which loads could cause damage to the ring gear teeth.

[0005] This invention was made in consideration of these circumstances and aims to measure how much load is applied to which teeth of a ring gear. [Means for solving the problem]

[0006] One embodiment of the present invention relates to the following [1] to

[11] .

[0007] [1] A movable part of a wind turbine having a ring gear having multiple teeth and a drive device having a pinion that meshes with the ring gear, wherein a load detection unit detects the applied load on the teeth of the ring gear when the driving force or external force of the drive device is applied via the pinion while the ring gear is meshed with the pinion, A load measurement system comprising: a positioning unit that identifies a target tooth to which the applied load is applied from among the plurality of teeth of the ring gear.

[0008] [2] When the movable part is driven, the driven part to which the drive device having the pinion is attached rotates relative to the ring gear, The position identification unit identifies the target tooth to which the applied load is applied from among the plurality of teeth of the ring gear, based on sensor information obtained from a sensor that detects the rotational position of the driven part with respect to the ring gear and position information of the pinion with respect to the driven part, as described in [1].

[0009] [3] The position identification unit identifies, from among the plurality of teeth of the ring gear, the target tooth to which the applied load is applied at the second time, based on the position information of the pinion relative to the ring gear at the first time and the amount of rotation information of the pinion between the first time and the second time. The load measurement system according to [1] or [2].

[0010] [4] The load detection unit distinguishes and detects the applied load on the teeth of the ring gear when the teeth of the pinion are in contact with the teeth of the ring gear from the first side in the circumferential direction of the ring gear, and the driving force or external force of the drive device is applied via the pinion, and the applied load on the teeth of the ring gear when the teeth of the pinion are in contact with the teeth of the ring gear from the second side opposite to the first side in the circumferential direction, and the driving force or external force of the drive device is applied via the pinion, and the load on the teeth of the ring gear is distinguished and detected, as described in any one of [1] to [3].

[0011] [5] The movable part rotates the nacelle of the wind turbine relative to the tower, The load measuring system according to any one of [1] to [4], wherein the movable part has a plurality of the drive devices.

[0012] A load measurement system as described in any of [6] [1] or [5], A damage rate estimation system comprising: a damage rate estimation unit that calculates the damage rate of the teeth of the ring gear from the applied load on the teeth of the ring gear measured within a certain period of time by the load measurement system.

[0013] [7] The damage rate estimation unit calculates an average load from the applied load on the teeth of the ring gear measured within a certain period of time by the load measurement system, and uses the average load to calculate the damage rate of the teeth of the ring gear, as described in [6].

[0014] The damage rate estimation system described in [8] [6] or [7], A life prediction system comprising: a life prediction unit that predicts the lifespan of the teeth of the ring gear based on the damage rate of the teeth of the ring gear calculated by the damage rate estimation system.

[0015] [9] A movable part of a wind turbine having a ring gear having a plurality of teeth and a drive device having a pinion that meshes with the ring gear, comprising a load detection step of detecting the applied load on the teeth of the ring gear when the driving force or external force of the drive device is applied via the pinion while the ring gear is meshed with the pinion, A load measurement method comprising: a positioning step of identifying a target tooth to which the applied load is applied from among the plurality of teeth of the ring gear.

[0016] A load measurement step of measuring the applied load on the teeth of the ring gear within a certain period of time using the load measurement method described in

[10] [9], A damage rate estimation step, which calculates the damage rate of the teeth of the ring gear from the applied load on the teeth of the ring gear measured within a certain period of time in the load measurement step, A damage rate monitoring method comprising: a warning step of issuing a warning if the damage rate calculated in the damage rate estimation step is equal to or greater than a standard value.

[0017]

[11] A computer comprises a load detection step for detecting an applied load on the teeth of a wind turbine having a ring gear having a plurality of teeth and a drive device having a pinion that meshes with the ring gear, when the drive device is applied via the pinion while the ring gear is meshed with the pinion, A program for causing a load measurement method to be executed, which includes a positioning step of identifying a target tooth to which the applied load is applied from among the plurality of teeth of the ring gear. [Effects of the Invention]

[0018] According to the present invention, it is possible to measure how much load is applied to which tooth of the ring gear.

Brief Description of the Drawings

[0019] [Figure 1] It is a perspective view showing a configuration example of a windmill in the present embodiment. [Figure 2] It is a top view showing a movable part in the present embodiment. [Figure 3] It is a diagram showing a configuration example of a drive device and a load detection unit in the present embodiment. [Figure 4] It is a diagram showing a period during which the drive device is driving and a period during which it is stopped in the present embodiment. [Figure 5] It is a diagram showing a configuration example of a load measurement system, a damage rate estimation system, and a life prediction system in the present embodiment. [Figure 6] It is a diagram showing an example of a graph displayed on a display unit in the present embodiment.

Modes for Carrying Out the Invention

[0020] The load measurement system 1, the damage rate estimation system 200, and the life prediction system 201 according to the embodiment of the present invention will be described in detail with reference to the drawings. The load measurement system 1, the damage rate estimation system 200, and the life prediction system 201 according to the present embodiment are applied to the movable part 11 of the windmill 10.

[0021] First, the windmill 10 to which the load measurement system 1, the damage rate estimation system 200, and the life prediction system 201 according to the present embodiment are applied will be described. FIG. 1 is a perspective view showing a configuration example of the windmill 10. The windmill 10 includes a windmill main body 101. The windmill main body 101 includes a tower 102, a nacelle 103, a rotor 104 (main shaft portion), and a plurality of blades 105 (blades). The tower 102 extends vertically upward on land or at sea.

[0022] The wind turbine 10 has a movable part 11 in addition to the wind turbine body 101. In this embodiment, the nacelle 103 is attached to the tower 102 so as to be rotatable relative to the top of the tower 102. That is, the connection between the tower 102 and the nacelle 103 is a movable part 11 that allows the nacelle 103 to rotate relative to the tower 102. The movable part 11 drives the nacelle 103 of the wind turbine 10 to rotate around the longitudinal direction of the tower 102 as the axis of rotation. That is, the movable part 11 rotates the nacelle 103 of the wind turbine 10 in the yaw direction relative to the tower 102. The tower 102 extends vertically. Therefore, the movable part 11 drives the nacelle 103 to rotate around an axis of rotation that extends vertically.

[0023] The rotor 104 rotates in the roll direction relative to the nacelle 103. Multiple blades (for example, three) 105 are mounted on the rotor 104 at equal angles to each other, extending radially from the axis of rotation in the roll direction.

[0024] Figure 2 is a top view showing the movable part 11 of the wind turbine 10 in this embodiment. The movable part 11 in this embodiment includes a ring gear 106 and a drive device 3.

[0025] The ring gear 106 has multiple teeth 106a. In the example shown in Figure 2, the ring gear 106 is assembled on the top of the tower 102. In this case, the ring gear 106 may have multiple internal teeth on its inner circumference as multiple teeth 106a. Although not shown, the ring gear 106 may also have multiple external teeth on its outer circumference as multiple teeth 106a.

[0026] The drive unit 3 has a pinion 34 that meshes with the ring gear 106. In the example shown in Figure 2, the drive unit 3 has a pinion 34 and an actuator 36 that drives the pinion 34. In the example shown in Figure 2, the movable part 11 has multiple drive units 3. In particular, the movable part 11 has four drive units 3. The four drive units 3 are referred to as drive units 3-1, 3-2, 3-3, and 3-4. When referring to the drive units 3 collectively, they are simply described as "drive unit 3".

[0027] Figure 3 shows an example configuration of the drive unit 3, along with an example configuration of the load detection unit 41 of the load measurement system 1. In the example shown in Figure 3, the ring gear 106 is located on the top of the tower 102.

[0028] The member to which the drive unit 3 is attached is referred to as the driven part 103a. In the example shown in Figure 3, the drive unit 3 is attached to the nacelle 103. Therefore, in the example shown in Figure 3, the nacelle 103 corresponds to the driven part 103a. As an example, the drive unit 3 is attached to the inside of the nacelle 103. Although not shown, the nacelle 103 may be provided with a ring gear corresponding to the ring gear 106, and the tower 102 may be provided with a drive unit corresponding to the drive unit 3. In other words, the tower 102 may correspond to the driven part 103a.

[0029] The drive unit 3 drives the movable part 11. In the example shown in Figure 2, the movable part 11 is driven by the cooperation of multiple drive units 3. When the movable part 11 is driven, the driven part 103a to which the drive unit 3 having a pinion 34 is attached rotates relative to the ring gear 106. In this embodiment, when the movable part 11 is driven, the nacelle 103 rotates relative to the tower 102. In this embodiment, the actuator 36 of the drive unit 3 generates a yaw driving force. When the actuator 36 is driven while the ring gear 106 is meshed with the pinion 34 of the drive unit 3, the drive unit 3 is driven to rotate in the circumferential direction DR of the ring gear 106 shown in Figure 2 by the driving force of the actuator 36. The drive unit 3 is rotatable in the first side SR1 in the circumferential direction DR. The drive unit 3 may also be rotatable in the second side SR2 in the circumferential direction DR.

[0030] The movable part 11 may be equipped with a brake that applies braking force to the rotation of the driven part 103a relative to the ring gear 106. In this embodiment, the movable part 11 is equipped with a hydraulic brake that applies braking force to the rotation of the driven part 103a relative to the ring gear 106. The hydraulic brake is, for example, a caliper brake mechanism. The hydraulic brake has a hydraulic brake drive unit (not shown) and a friction body 50 shown in Figure 2. The hydraulic brake drive unit is fixed to the driven part 103a. The hydraulic brake drive unit moves the friction body 50 in a direction perpendicular to the plane of the paper in Figure 2 (the direction in which the shaft 33 of the actuator 36, which will be described later, extends) in response to a control signal supplied from the outside. The hydraulic brake drive unit applies braking force to the rotation of the driven part 103a relative to the ring gear 106 by pressing the friction body 50 against the ring gear 106. It is desirable that the wind turbine 10 can adjust the braking force applied.

[0031] The drive unit 3 is fixed to the driven part 103a by N (where N is an integer of 2 or more) bolts 35. The N bolts 35 are arranged circumferentially. In this embodiment, the drive unit 3 is fixed to the nacelle 103 by the bolts 35.

[0032] The actuator 36 comprises a drive unit 30, a braking unit 31, a reduction gear 32, and a shaft 33. The reduction gear 32 includes gears as a reduction mechanism. The pinion 34 is provided at the end of the shaft 33 so as to mesh with the ring gear 106. Bolts 35-1 to 35-N are members that fix the drive unit 3 to the nacelle 103. As will be described later, when the ring gear 106 is meshed with the pinion 34, a load may be applied to both the teeth 106a of the ring gear 106 and the teeth of the pinion 34. Details of the situation in which a load is applied to both the teeth 106a of the ring gear 106 and the teeth of the pinion 34 will be described later. In response to this load, the bolt 35 becomes distorted.

[0033] The drive unit 30 is a motor. The drive unit 30 rotates the shaft 33 with its longitudinal direction as the axis of rotation, according to the voltage and current supplied to the drive unit 30. The actuator 36 also includes a braking unit 31 that applies a braking force to the rotation of the shaft 33. In this embodiment, the braking unit 31 uses an electromagnetic brake to suppress the rotational speed of the shaft 33. The braking unit 31 may also use an electromagnetic brake to maintain a stopped state of rotation of the shaft 33. The reduction gear 32 uses gears provided in the reduction gear 32 to determine the rotational speed of the shaft 33.

[0034] The shaft 33 rotates at a rotational speed determined by the reduction gear 32 when driven by the drive unit 30. The shaft 33 rotates with a predetermined torque (shaft torque) when driven by the drive unit 30. The pinion 34 rotates in accordance with the amount of rotation of the shaft 33, meshing with the internal teeth of the ring gear 106. As a result, the driven part 103a rotates relative to the ring gear 106. In this embodiment, the nacelle 103 rotates relative to the tower 102.

[0035] Figure 4 shows the periods in which the drive unit 3 takes on two different modes in this embodiment. The wind turbine 10 takes on different modes during the drive period when the drive unit 3 is running and during the stop period when the drive unit 3 is stopped, as shown in Figure 4, for example. The drive period is the period during which the orientation of the nacelle 103 is moved based on the wind direction. The stop period is the period during which the orientation of the nacelle 103 is fixed. During the drive period, the drive unit 3 moves the nacelle 103 relative to the tower 102 to the target position. During the stop period, the drive unit 3 stops the nacelle 103 relative to the tower 102 at the target position. The target position is the optimal position of the nacelle 103 relative to the tower 102, which is determined based on the wind direction.

[0036] When the start of the drive period arrives, the drive unit 3 moves the nacelle 103 relative to the tower 102 to the target position. The drive unit 3 positions the nacelle 103 to the target position before the end of the drive period arrives. During the stop period, the drive unit 3 generates a braking force to fix the position of the nacelle 103 at the target position.

[0037] The wind turbine 10 of this embodiment further includes a sensor 47, as shown in Figure 5 (described later), which detects the rotational position of the driven unit 103a relative to the ring gear 106. This sensor 47 is also referred to as an azimuth sensor 47. As an example, the azimuth sensor 47 detects the angle α described below. One of the positions that the driven unit 103a can take relative to the ring gear 106 is defined as the reference position. Then, the rotation angle α of the driven unit 103a is detected, which is necessary to move the driven unit 103a from the reference position to the current position. In particular, the azimuth sensor 47 of this embodiment detects the rotational position of the nacelle 103, which is the driven unit 103a, relative to the ring gear 106. Furthermore, the wind turbine 10 of this embodiment is equipped with a wind direction sensor that detects the direction of the wind. In this embodiment, the wind turbine 10 determines a target position for moving the orientation of the nacelle 103 during the drive period, taking into consideration the rotational position of the nacelle 103 relative to the ring gear 106 detected by the azimuth sensor 47 and the wind direction detected by the wind direction sensor.

[0038] In the movable part 11 of the wind turbine 10, when the ring gear 106 is meshed with the pinion 34, loads may be applied to both the teeth 106a of the ring gear 106 and the teeth of the pinion 34. In the example shown in Figure 2, among the multiple teeth 106a of the ring gear 106, the teeth 106a that are in contact with the teeth of the pinion 34 due to the ring gear 106 being meshed with the pinion 34 may be subjected to a load from the pinion 34.

[0039] A more specific example of the load applied to both the teeth 106a of the ring gear 106 and the teeth of the pinion 34 will be described. During the above-mentioned driving period, with the ring gear 106 meshed with the pinion 34, the drive unit 3 drives the movable part 11 by driving the pinion 34 of the drive unit 3. At this time, the pinion 34 rotates while meshing with the teeth 106a of the ring gear 106, in accordance with the amount of rotation of the shaft 33. At this time, with the ring gear 106 meshed with the pinion 34, the driving force of the drive unit 3 is applied via the pinion 34, and a load is applied from the pinion 34 to the teeth 106a of the ring gear 106 that are meshed with the pinion 34.

[0040] Furthermore, if an external force such as a gust of wind is applied to the ring gear 106 or the driven part 103a, etc., while the ring gear 106 is meshed with the pinion 34, a load will be applied to both the teeth 106a of the ring gear 106 and the teeth of the pinion 34. In this case as well, a load will be applied from the pinion 34 to the teeth 106a of the ring gear 106 that are meshed with the pinion 34. Such loads due to external forces can occur during both the driving period and the stopping period as described above.

[0041] As described above, the load applied to the teeth 106a of the ring gear 106 when the driving force of the drive unit 3 or an external force is applied via the pinion 34 while the ring gear 106 is meshed with the pinion 34 is referred to as the applied load. The tooth 106a on which this applied load is applied is also referred to as the target tooth 106b.

[0042] As described above, when a load is applied to the target tooth 106b of the ring gear 106, a load corresponding to the applied load is also applied to the teeth of the pinion 34 that meshes with the ring gear 106. This load can act on the fixture that fixes the drive unit 3 to the driven unit 103a. This load imparts tensile stress, compressive stress, and bending stress to the fixture that fixes the drive unit 3 to the driven unit 103a.

[0043] Next, the load measurement system 1 of this embodiment will be described. The load measurement system 1 measures how much load is applied to which of the multiple teeth 106a of the ring gear 106. In particular, the load measurement system 1 measures how much of the above-mentioned applied load is applied to which of the multiple teeth 106a of the ring gear 106. Figure 5 is a block diagram showing the load measurement system 1 of this embodiment, as well as the damage rate estimation system 200 and life prediction system 201 equipped with the load measurement system 1, together with the components of the wind turbine 10. As shown in Figure 5, the load measurement system 1 includes a load detection unit 41 and a position identification unit 42.

[0044] As an example, the load measurement system 1 includes an IoT device installed on the wind turbine 10. This IoT device is installed on the nacelle 103 of the wind turbine 10. As an example, the IoT device included in the load measurement system 1 includes a load detection unit 41 and a position identification unit 42.

[0045] The IoT device installed on the wind turbine 10 may have a control unit. The control unit is, for example, a programmable logic controller (PLC). The control unit may also include a load detection unit 41 and a position identification unit 42. That is, the control unit may function as both the load detection unit 41 and the position identification unit 42.

[0046] The IoT device installed on the wind turbine 10 may have an output unit that outputs information possessed by the IoT device. The output unit is, for example, a communication gateway for the IoT device. Let's consider the case where the IoT device includes a load detection unit 41 and a position identification unit 42, but does not include a calculation unit 40, which will be described later. In this case, the IoT device may be connected to the calculation unit 40, which will be described later, via a communication line at its output unit. The output unit of the IoT device may output the information acquired by the load detection unit 41 to the calculation unit 40 via the communication line. The output unit of the IoT device may output information about the target tooth 106b identified by the position identification unit 42 to the calculation unit 40 via the communication line.

[0047] The load detection unit 41 detects the applied load on the teeth 106a of the ring gear 106 in the movable part 11 of the wind turbine 10. The applied load on the teeth 106a of the ring gear 106 detected by the load detection unit 41 includes the applied load on the teeth 106a of the ring gear 106 due to the driving of the pinion 34 of the drive unit 3, and the applied load on the teeth 106a of the ring gear 106 due to external forces such as gusts of wind being applied to the wind turbine 10. The applied load detected by the load detection unit 41 occurs both when the pinion 34 of the drive unit 3 is driving and when the pinion 34 is not driving. While the pinion 34 is driving, the teeth 106a of the ring gear 106 are subjected to the applied load due to the driving of the pinion 34 and the applied load due to external forces such as wind. While the pinion 34 is not driving, the teeth 106a of the ring gear 106 are subjected to the applied load due to external forces such as wind.

[0048] Detecting the applied load on the teeth 106a of the ring gear 106 involves measuring a physical quantity that represents the applied load on the teeth 106a of the ring gear 106. Detecting the applied load on the teeth 106a of the ring gear 106 involves obtaining information that can be used to derive the applied load on the teeth 106a of the ring gear 106. Information that can be used to derive the applied load on the teeth 106a of the ring gear 106 is, for example, information that can be used to estimate the damage rate of the target teeth 106b of the ring gear 106, as described later. Information that can be used to derive the applied load on the teeth 106a of the ring gear 106 may also be information that can be used to measure the average load, as described later.

[0049] The applied load on the teeth 106a of the ring gear 106 includes the load applied when the teeth of the pinion 34 are in contact with the teeth of the ring gear 106 from the first side SR1 in the circumferential direction DR of the ring gear 106, and the driving force of the drive unit 3 or an external force is applied via the pinion 34. This applied load is also referred to as the first side load. The applied load on the teeth 106a of the ring gear 106 also includes the load applied when the teeth of the pinion 34 are in contact with the teeth of the ring gear 106 from the second side SR2 in the circumferential direction DR of the ring gear 106, and the driving force of the drive unit 3 or an external force is applied via the pinion 34. This applied load is also referred to as the second side load. The load detection unit 41 of this embodiment does not distinguish between the first side load and the second side load.

[0050] In this embodiment, the load detection unit 41 has torque sensors. In particular, the load detection unit 41 has multiple torque sensors, each of which is provided for a plurality of drive devices 3.

[0051] In the examples shown in Figures 3 and 5, the load detection unit 41 has a strain sensor 20 as a torque sensor, which is a device for measuring the amount of strain in the bolts 35. The amount of strain is the amount of deformation. The strain sensor 20-n (where n is an integer between 1 and N) is provided on the bolts 35-n. When the ring gear 106 is meshed with the pinion 34, strain occurs in each bolt 35 that fixes the drive unit 3 having the pinion 34, in accordance with the load applied to the teeth of the pinion 34. The strain sensor 20-n detects the amount of strain in the bolts 35-n. According to the strain sensor 20, the load applied to the teeth of the pinion 34 when the ring gear 106 is meshed with the pinion 34 can be detected from the strain of each bolt 35. Based on this detection result, the applied load on the teeth 106a of the ring gear 106, which is considered to correspond to the load applied to the teeth of the pinion 34, can be detected.

[0052] Although not shown in the figures, the load detection unit 41 may have sensors other than the strain sensor 20 that can detect the applied load on the teeth 106a of the ring gear 106. The load detection unit 41 may have multiple types of sensors and detect the applied load on the teeth 106a of the ring gear 106 based on the information acquired by these multiple types of sensors.

[0053] In this embodiment, the movable part 11 has a plurality of drive devices 3. Each of the plurality of drive devices 3 has a pinion 34 that meshes with the ring gear 106. In this case, the load detection unit 41 detects the applied load on the teeth 106a of the ring gear 106 when the driving force or external force of the drive device 3 is applied via each of the plurality of pinions 34. More specifically, if the movable part 11 has four drive units 3, namely drive units 3-1 to 3-4, the load detection unit 41 detects the applied load on the teeth 106a of the ring gear 106 when the driving force or external force of drive unit 3-1 is applied via the pinion 34 of drive unit 3-1; the applied load on the teeth 106a of the ring gear 106 when the driving force or external force of drive unit 3-2 is applied via the pinion 34 of drive unit 3-2; the applied load on the teeth 106a of the ring gear 106 when the driving force or external force of drive unit 3-3 is applied via the pinion 34 of drive unit 3-3; and the applied load on the teeth 106a of the ring gear 106 when the driving force or external force of drive unit 3-4 is applied via the pinion 34 of drive unit 3-4. As an example, the load detection unit 41 simultaneously detects the applied load on the teeth 106a of the ring gear 106 as the driving force or external force of the drive unit 3 is applied through each of the multiple pinions 34. More specifically, if the movable part 11 has four drive units 3, namely drive units 3-1 to 3-4, the load detection unit 41 simultaneously detects the applied load on the teeth 106a of the ring gear 106 due to the driving force or external force of drive unit 3-1 being applied via the pinion 34 of drive unit 3-1, the applied load on the teeth 106a of the ring gear 106 due to the driving force or external force of drive unit 3-2 being applied via the pinion 34 of drive unit 3-2, the applied load on the teeth 106a of the ring gear 106 due to the driving force or external force of drive unit 3-3 being applied via the pinion 34 of drive unit 3-3, and the applied load on the teeth 106a of the ring gear 106 due to the driving force or external force of drive unit 3-4 being applied via the pinion 34 of drive unit 3-4.

[0054] The load detection unit 41 in this embodiment has an input terminal for the PLC. In this embodiment, the input terminal is connected to the strain sensor 20 of the load detection unit 41.

[0055] The position identification unit 42 uses the azimuth angle sensor 47 to identify the target tooth 106b on which the applied load is applied from among the multiple teeth 106a of the ring gear 106. As described above, the load detection unit 41 of this embodiment has a strain sensor 20. The strain sensor 20 can detect the load applied to the teeth 106a of the pinion 34 when the ring gear 106 is meshed with the pinion 34. However, the strain sensor 20 does not necessarily make it clear which of the multiple teeth 106a of the ring gear 106 is the target tooth 106b on which the applied load is applied. In the example shown in Figure 2, the ring gear 106 has M teeth 106a, from tooth 106a-1 to 106a-M. The strain sensor 20 does not necessarily make it clear which of these teeth 106a-1 to 106a-M is the target tooth 106b. In this regard, the position identification unit 42 can identify the target tooth 106b from among the teeth 106a-1 to 106a-M.

[0056] The position identification unit 42 identifies the target tooth 106b on which the load is applied at the time the load detection unit 41 detects the applied load on the tooth 106a of the ring gear 106.

[0057] In this embodiment, the position identification unit 42 identifies the target tooth 106b from sensor information obtained from a sensor 47 that detects the rotational position of the driven unit 103a relative to the ring gear 106, i.e., the azimuth angle sensor 47 described above, and the position information of the pinion 34 relative to the driven unit 103a. The position information of the pinion 34 relative to the driven unit 103a is, for example, information regarding the relative positional relationship between the driven unit 103a and the rotating axis of the pinion 34. When the driven unit 103a rotates relative to the ring gear 106, the position of the rotating axis of the pinion 34 also rotates relative to the ring gear 106 together with the driven unit 103a. The rotation of the driven unit 103a relative to the ring gear 106 does not change the relative positional relationship between the driven unit 103a and the rotating axis of the pinion 34. By determining the position of the pinion 34 relative to the driven part 103a from the position information, and by determining the position of the driven part 103a relative to the ring gear 106 from the sensor information obtained from the azimuth angle sensor 47, the position of the pinion 34 relative to the ring gear 106 can be identified. This makes it possible to identify the target tooth 106b to which the applied load is applied from among the multiple teeth 106a of the ring gear 106.

[0058] In this embodiment, the position identification unit 42 identifies the target tooth 106b from among the teeth 106a-1 to 106a-M. In the example shown in Figure 2, the pinion 34 of the drive unit 3-1 is in contact with tooth 106a-1. Tooth 106a-1 is the target tooth 106b to which an applied load is applied when the ring gear 106 is subjected to the driving force of the drive unit 3-1 or an external force applied via the pinion 34 of the drive unit 3-1.

[0059] In this embodiment, the movable part 11 has a plurality of drive devices 3. Each of the plurality of drive devices 3 has a pinion 34 that meshes with the ring gear 106. In this case, the position identification unit 42 identifies the target tooth 106b to which an applied load is applied by the driving force or external force of the drive device 3 applied through each of the plurality of pinions 34. In this case, a number of target teeth 106b corresponding to the number of pinions 34 are identified. More specifically, in this embodiment, the movable part 11 has four drive devices 3, namely drive devices 3-1 to 3-4. In this case, the load detection unit 41 identifies the target teeth 106b to which an applied load is applied when the driving force or external force of the drive unit 3-1 is applied via the pinion 34 of the drive unit 3-1, the target teeth 106b to which an applied load is applied when the driving force or external force of the drive unit 3-2 is applied via the pinion 34 of the drive unit 3-2, the target teeth 106b to which an applied load is applied when the driving force or external force of the drive unit 3-3 is applied via the drive unit 3-3, and the target teeth 106b to which an applied load is applied when the driving force or external force of the drive unit 3-4 is applied via the drive unit 3-4.

[0060] According to the load measurement system 1 of this embodiment, the load detection unit 41 and the position identification unit 42 can measure which of the multiple teeth 106a of the ring gear 106 is being subjected to what degree of applied load.

[0061] Next, the load measurement method of this embodiment will be described. The load measurement method can be performed using the load measurement system 1 of this embodiment described above. The load measurement method comprises a load detection step and a position identification step.

[0062] In the load detection process, the applied load on the teeth of the ring gear 106 is detected in the movable part 11 of the wind turbine 10. The load detection process can be performed using the load detection unit 41 described above.

[0063] In this embodiment, the movable part 11 has a plurality of drive devices 3. Each of the plurality of drive devices 3 has a pinion 34 that meshes with the ring gear 106. In this case, during the load detection process, the applied load on the teeth 106a of the ring gear 106 is detected by applying the driving force or external force of the drive device 3 through each of the plurality of pinions 34. As an example, during the load detection process, the applied load on the teeth 106a of the ring gear 106 is detected simultaneously by applying the driving force or external force of the drive device 3 through each of the plurality of pinions 34.

[0064] In the positioning step, the target tooth 106b to which the applied load is applied is identified from among the multiple teeth 106a of the ring gear 106. The positioning step can be performed using the positioning unit 42 described above. In the positioning step, the target tooth 106b to which the applied load is applied is identified at the time the applied load on the teeth 106a of the ring gear 106 is detected in the load detection step.

[0065] In this embodiment, the movable part 11 has a plurality of drive devices 3. Each of the plurality of drive devices 3 has a pinion 34 that meshes with the ring gear 106. In this case, during the load detection step, the target tooth 106b to which the applied load is applied is identified by applying the driving force of the drive device 3 or an external force through each of the plurality of pinions 34.

[0066] According to the load measurement method of this embodiment, the load detection step and the position identification step make it possible to measure which of the multiple teeth 106a of the ring gear 106 is being subjected to what degree of applied load.

[0067] The measurement of how much load is applied to each of the multiple teeth 106a may be performed multiple times within a certain period. This measurement may also be performed periodically. When this measurement is performed multiple times within a certain period, from the viewpoint of obtaining measurement results when the movable part 11 is in various states, it is preferable that the interval between measurements be sufficiently shorter than the driving period and the stopping period shown in Figure 4 and described above. In addition, the applied load fluctuates with a period even shorter than the period during which the driving period and the stopping period switch. For example, when the rotor 104 and blades 105 of the wind turbine 10 are rotating, the applied load may fluctuate periodically depending on the rotation period of the rotor 104 and blades 105 and the number of blades 105. The applied load may fluctuate at a frequency of, for example, about 1 Hz. The interval between measurements is preferably determined according to the period or amplitude of the fluctuation of the applied load, which fluctuates with a short period as described above. The interval between measurements is preferably determined according to the period or amplitude of the fluctuation of the applied load so as to improve the accuracy of estimating the damage rate, which will be described later.

[0068] The load measurement method of this embodiment may include a display step. The display step can be performed using the display unit 45 shown in Figure 5. Details of the display unit 45 will be described later. In the display step, the display unit 45 may display information acquired by the load detection unit 41. The display unit 45 may also display information regarding the target tooth 106b identified by the position identification unit 42. The display unit 45 may also display which of the multiple teeth 106a of the ring gear 106 has been identified as the target tooth 106b. The display unit 45 may also display which of the teeth 106a-1 to 106a-M has been identified as the target tooth 106b. The display unit 45 may also display which of the multiple teeth 106a of the ring gear 106 is the target tooth 106b to which the applied load is applied, and the magnitude of the applied load on the target tooth 106b. The display unit 45 may display sensor information obtained from the azimuth sensor 47 described above, as well as position information of the pinion 34 relative to the driven unit 103a.

[0069] As described above, the load measurement system 1 and load measurement method of this embodiment can measure how much load is applied to each of the multiple teeth 106a of the ring gear 106. In particular, when the movable part 11 has multiple drive devices 3, each of the pinions 34 of the multiple drive devices 3 meshes with the ring gear 106. In this case, it is possible to measure how much load is applied to each of the multiple teeth 106a when each of the pinions 34 of the multiple drive devices 3 is meshed with the ring gear 106. In particular, when the movable part 11 rotates the nacelle 103 of the wind turbine 10 relative to the tower 102, it is possible to measure how much load is applied to each of the multiple teeth 106a of the ring gear 106.

[0070] In particular, according to the load measurement system 1 and load measurement method of this embodiment, it is possible to grasp in real time which teeth of the multiple teeth 106a are being subjected to the applied load and to what extent in the operating wind turbine 10, and to utilize this information for controlling the wind turbine 10 and for maintaining the ring gear 106. As an example, consider a situation in which, based on the information on which teeth of the multiple teeth 106a are being subjected to the load and to what extent, it is measured that a large applied load is being applied to some of the teeth 106a due to the wind hitting the wind turbine 10. In this situation, if the brake that applies braking force to the rotation of the driven part 103a relative to the ring gear 106 (for example, a brake having a friction body 50 as shown in Figure 2, which applies braking force to the rotation of the driven part 103a relative to the ring gear 106 by pressing the friction body 50 against the ring gear 106) is activated, control may be performed to release the brake. By releasing the brake, rotation of the driven part 103a relative to the ring gear 106 is permitted. This makes it possible to relieve the applied load on some of the teeth 106a. In the above situation, control may be performed to change the orientation of the blade 105 so that the direction in which the blade 105 extends is parallel to the mounting surface of the wind turbine 10. This makes the blade 105 less susceptible to wind, and suppresses the transmission of wind force to the teeth 106a of the ring gear 106 via the blade 105, thereby preventing a large applied load from being placed on the teeth 106a.

[0071] The load measurement method using the load measurement system 1 of this embodiment makes it easy to measure how much load is applied to each of the multiple teeth 106a multiple times within a certain period. It also makes it easy to perform the measurement periodically. In particular, by repeatedly performing the measurement at intervals sufficiently shorter than the driving period and stopping period described above, it becomes easy to obtain measurement results when the movable part 11 is in various states. This allows the measurement results when the movable part 11 is in various states to be used for controlling the wind turbine 10 and for maintaining the ring gear 106. Furthermore, by performing the measurement multiple times within a certain period, it is also possible to implement the damage rate monitoring method and life prediction method described later. In particular, as described above, the applied load fluctuates in short periods and can fluctuate at frequencies of, for example, about 1 Hz. For this reason, from the viewpoint of accurately estimating the damage rate from the measured applied load, it is preferable to perform the measurement as many times as possible at the shortest possible intervals. In this regard, the load measurement method using the load measurement system 1 of this embodiment is preferable because it allows the measurement to be performed many times at short intervals.

[0072] An abnormality in the ring gear 106 may be detected from the measurement results of the load measurement system 1 and load measurement method of this embodiment, which measure how much load is applied to which of the multiple teeth 106a. For example, an abnormality such as excessive wear on the teeth 106a of the ring gear 106, a missing tooth 106a, or distortion of the ring gear 106 may be detected from the measurement results. An abnormality in the drive unit 3, for example, an abnormality in the pinion 34 of the drive unit 3, may also be detected from the measurement results. In this case, an abnormality in the ring gear 106 or the drive unit 3 may be detected from a single measurement result for one tooth 106a (for example, tooth 106a-1). An abnormality in the ring gear 106 or the drive unit 3 may also be detected from measurement results for multiple teeth 106a (for example, two teeth, tooth 106a-1 and tooth 106a-2). An abnormality in the ring gear 106 or the drive unit 3 may be detected from multiple measurement results at different time points for a single tooth 106a (for example, tooth 106a-1).

[0073] Next, the damage rate estimation system 200 of this embodiment will be described. The damage rate estimation system 200 of this embodiment comprises the load measurement system 1 of this embodiment described above and a damage rate estimation unit 44. The damage rate estimation unit 44 calculates the damage rate of the teeth 106a of the ring gear 106 from the applied load on the teeth 106a of the ring gear 106 measured by the load measurement system 1 within a certain period of time. In the example shown in Figure 5, the damage rate estimation unit 44 is included in the calculation unit 40 which will be described later.

[0074] As an example, the damage rate estimation system 200 is installed on the wind turbine 10 and includes an IoT device that includes a load detection unit 41 and a position identification unit 42. The IoT device is installed on the nacelle 103 of the wind turbine 10. In this case, the damage rate estimation system 200 includes a load measurement system 1 by including the IoT device. The IoT device included in the damage rate estimation system 200 may include a load detection unit 41, a position identification unit 42 and a calculation unit 40. In this case, the damage rate estimation system 200 can be said to include a load measurement system 1 having a load detection unit 41 and a position identification unit 42, and a calculation unit 40 including a damage rate estimation unit 44.

[0075] The control unit of the IoT device installed on the wind turbine 10 may include a calculation unit 40. That is, the control unit may function as a calculation unit 40. The control unit may function as a calculation unit 40 that includes a load detection unit 41, a position identification unit 42, and a damage rate estimation unit 44.

[0076] The damage rate estimation system 200 may include, in addition to IoT devices installed on the wind turbine 10, a computer connected to the IoT devices via a communication line. In this case, the computer may be, for example, a server, workstation, personal computer, tablet terminal, or smartphone terminal. The computer may be installed in the office of the manager of the wind turbine 10. In this case, the IoT devices may include a load detection unit 41 and a position identification unit 42, and the computer connected to the IoT devices may include a calculation unit 40. That is, the computer connected to the IoT devices may function as the calculation unit 40.

[0077] The damage rate estimation system 200 may include, in addition to the IoT device installed on the wind turbine 10, a plurality of computers that are distributed, connected to each other via communication lines, and connected to the IoT device via communication lines. In this case, the plurality of computers may perform cloud computing by communicating with each other via communication lines. In this case, the calculation unit 40 may be the plurality of computers connected to the IoT device. That is, the plurality of computers connected to the IoT device may function as the calculation unit 40 through cloud computing.

[0078] Although not shown in the diagram, at least one of the computers included in the IoT device or the computer connected to the IoT device may include a storage unit. For example, the storage unit stores a program for causing the computer to execute a load measurement method, as well as a damage rate estimation method, a damage rate monitoring method, and a life prediction method, which will be described later. Part or all of the load detection unit 41 and the position identification unit 42 are realized by a processor such as a CPU (Central Processing Unit) executing a program stored in the storage unit. Part or all of the damage rate estimation unit 44 and the life prediction unit 46, which will be described later, may also be realized by a processor such as a CPU (Central Processing Unit) executing a program stored in the storage unit. For example, the storage unit is a computer-readable recording medium. The storage unit is preferably a non-volatile recording medium (non-temporary recording medium) such as flash memory or an HDD (Hard Disk Drive). The storage unit may also include a volatile recording medium such as RAM (Random Access Memory). Some or all of the load detection unit 41, position identification unit 42, damage rate estimation unit 44, and life prediction unit 46 may be implemented using hardware such as LSI (Large Scale Integration) or ASIC (Application Specific Integrated Circuit).

[0079] Let's explain the meaning of the damage rate. During the operation of the wind turbine 10, the teeth 106a of the ring gear 106 are subjected to repeated loads. Due to these repeated loads, the teeth 106a gradually transition to a state where they are prone to fatigue failure, and unless the teeth 106a are replaced with new ones or the applied load on the teeth 106a is reduced, fatigue failure will eventually occur. The damage rate is a numerical value that represents how close the teeth 106a are to fatigue failure. Specific examples of the damage rate will be discussed later.

[0080] In the damage rate estimation system 200 of this embodiment, the load measurement system 1 measures how much load is being applied to which of the multiple teeth 106a multiple teeth multiple times within a certain period. In particular, the load measurement system 1 performs these measurements periodically.

[0081] If the measurement is performed periodically within a certain period, the tooth 106a identified as the target tooth 106b on which the applied load is applied, and the magnitude of the applied load measured, will vary depending on the time the measurement is performed. As an example, consider the case where, at the start time S of the period during which the measurement is performed periodically, the pinion 34 of the drive unit 3-1 is in contact with tooth 106a-1, and an applied load is being applied to tooth 106a-1. In this case, at time C, which is later than the start time S, it is possible that the pinion 34 of the drive unit 3-1 is in contact with tooth 106a-1, but the applied load on tooth 106a-1 is measured to be smaller. At time D, which is later than the start time S, it is possible that the pinion 34 of the drive unit 3-1 is not in contact with tooth 106a-1, but the pinion 34 of the drive unit 3-2 is in contact with tooth 106a-1, and therefore an applied load is being applied to tooth 106a-1. At time E, which is later than the start time S, it is possible that none of the pinions 34 of the drive units 3-1 to 3-4 are in contact with tooth 106a-1, and therefore no applied load is detected on tooth 106a-1. By performing the above measurement periodically within a certain period, data on the periodically measured applied load for one tooth 106a (for example, tooth 106a-1) can be accumulated. By performing the above measurement periodically within a certain period, it is also possible to accumulate data on the periodically measured applied load for each of multiple teeth 106a. For example, it is possible to accumulate data on the periodically measured applied load for each of the teeth from 106a-1 to 106a-M.

[0082] The damage rate estimation unit 44 of this embodiment calculates the damage rate of a single tooth 106a (for example, tooth 106a-1) from the accumulation of periodically measured applied load data for that tooth 106a.

[0083] The damage rate estimation unit 44 of this embodiment calculates the average load from the applied load on the teeth 106a of the ring gear 106 measured by the load measurement system 1 within a certain period of time, and uses this average load to calculate the damage rate of the teeth 106a of the ring gear 106.

[0084] Let's explain the meaning of average load. As mentioned above, the applied load on the teeth 106a of the ring gear 106 can fluctuate periodically depending on the time at which the applied load is measured. Thus, let's consider a load condition X in which the applied load on the object can fluctuate periodically. Furthermore, let's consider a constant load value such that, when this constant load is repeatedly applied to the object with the same period as the fluctuation period of the applied load, it gives the object a fatigue life equal to the fatigue life of the object under the above load condition X. This constant load value is the average load for load condition X. The average load calculated from the applied load on the teeth 106a of the ring gear 106 is a constant load value such that it gives the tooth 106a a fatigue life equal to the fatigue life of the tooth 106a under the load condition in which the tooth 106a is placed.

[0085] By using the average load described above, the damage rate of the teeth 106a of the ring gear 106 can be calculated.

[0086] The damage rate estimation unit 44 of this embodiment calculates the average load for a single tooth 106a from the accumulated data of periodically measured applied loads for that tooth 106a. As an example, the average load can be calculated according to German Industrial Standard DIN3990-6 1994-12 Method III.

[0087] When considering cases where repeated loads are applied to an object, such as the teeth 106a of a ring gear 106, it is known that if the repeated load applied to the object is below a certain value, it will have little effect on the fatigue life of the object. In other words, if the repeated load applied to the object is below a certain value, it is known that the object may not reach fatigue failure no matter how many times the repeated load is applied to it. Taking this into consideration, when calculating the average load for a single tooth 106a from the accumulated data of periodically measured applied loads, if the applied load on the tooth 106a measured at a certain time is below a certain value, the applied load at that time may be considered zero, and the average load may be calculated. This simplifies the calculation of the average load. Furthermore, by excluding small applied loads that have little effect on the fatigue life of the object from the calculation, a more realistic damage rate can be calculated.

[0088] In this embodiment, the damage rate R of one tooth 106a of the ring gear 106 can be calculated as follows: the average load T of the load conditions on the tooth 106a from the initial state time H to the calculation time G. eq Therefore, the allowable number of repetitions is N. P Calculate the allowable number of repetitions N. P The average load T is applied to tooth 106a, which is the subject of the calculation of the damage rate R. eq This is the maximum number of repetitions at which the tooth 106a does not experience fatigue failure when the load is repeatedly applied. Furthermore, it is the actual number of repetitions of the applied load at calculation time G. A We will find the actual number of repetitions N. A This is the number of times the applied load fluctuated periodically between the initial state time H, when tooth 106a, the subject of the damage rate R calculation, is in an initial state where it is not subjected to repeated loading, and the calculation time G, when the damage rate R is calculated. The damage rate R is the actual number of repetitions N A Allows for N repetitions P This is the value obtained by dividing by [a certain factor].

[0089] For example, the applied load fluctuates with a 1-second cycle. In this case, the load measurement process and the damage rate estimation process may be performed with a 1-second cycle.

[0090] The initial state time H can be the start time S of a certain period during which the amount of applied load on each of the multiple teeth 106a is measured. That is, at the start time S of the certain period, the teeth 106a of the ring gear 106 may be in the initial state described above. At the start time S of the certain period, all of the multiple teeth 106a of the ring gear 106 may be in the initial state described above. The time when the wind turbine 10 starts operating may also be the start time S of the certain period. In this case, at the start time S, all of the multiple teeth 106a of the ring gear 106 can be considered to be in the initial state described above.

[0091] The damage rate estimation unit 44 of this embodiment may calculate the damage rate of each of the multiple teeth 106a (for example, teeth 106a-1 to 106a-M) from the accumulation of periodically measured applied load data for each of the multiple teeth 106a.

[0092] As shown in Figure 5, the damage rate estimation system 200 may further include a display unit 45. The display unit 45 is, for example, a display device such as a liquid crystal display or an organic EL (Electro-Luminescence) display. The display unit 45 may also include an operating device such as a touch panel. If the damage rate estimation system 200 includes a computer connected to an IoT device installed on the wind turbine 10, the display unit 45 may be the screen of the computer.

[0093] In the damage rate estimation system 200 of this embodiment, the display unit 45 may display information regarding the damage rate calculated by the damage rate estimation unit 44. The display unit 45 may display the damage rate value of one tooth 106a of the ring gear 106. The display unit 45 may display the average load value for one tooth 106a of the ring gear 106. When the damage rate estimation unit 44 calculates the damage rate for each of multiple teeth 106a of the ring gear 106, the display unit 45 may display the damage rate value for each of the multiple teeth 106a. The display unit 45 may display the average load value for each of the multiple teeth 106a. The display unit 45 may display the damage rate values ​​for each of the multiple teeth 106a (tooths 106a-1 to 106a-M) using a circular graph as shown in Figure 6. The circular graph shown in Figure 6 indicates that the further the position of the line L1 from the center C1 of the circular graph is, the greater the damage rate of the corresponding tooth 106a.

[0094] The display unit 45 may display information acquired by the load detection unit 41. The display unit 45 may display information regarding the target tooth 106b identified by the position identification unit 42. The display unit 45 may indicate which of the multiple teeth 106a of the ring gear 106 has been identified as the target tooth 106b. The display unit 45 may indicate which of the teeth 106a-1 to 106a-M has been identified as the target tooth 106b. The display unit 45 may also display which of the multiple teeth 106a of the ring gear 106 is the target tooth 106b to which the applied load is applied, and the magnitude of the applied load on the target tooth 106b. The display unit 45 may also display sensor information obtained from the azimuth sensor 47 described above, and position information of the pinion 34 relative to the driven unit 103a.

[0095] Next, the damage rate monitoring method of this embodiment will be described. The damage rate monitoring method of this embodiment can be performed using the damage rate estimation system 200 of this embodiment described above. The damage rate monitoring method comprises a load measurement step, a damage rate estimation step, and a warning step. The damage rate monitoring method may further include a damage rate display step.

[0096] In the load measurement process, the applied load on the teeth 106a of the ring gear 106 over a certain period of time is measured using the load measurement method described above. In the load measurement process of this embodiment, the amount of applied load on each of the multiple teeth 106a is measured multiple times over a certain period of time. In particular, in the load measurement process, this measurement is performed periodically.

[0097] In the damage rate estimation step, the damage rate of the teeth 106a of the ring gear 106 is calculated from the applied load on the teeth 106a of the ring gear 106 measured within a certain period in the load measurement step. The damage rate estimation step can be performed using the damage rate estimation unit 44 described above. In the damage rate estimation step, the damage rate of one tooth 106a (e.g., tooth 106a-1) may be calculated from the accumulated data of the applied load measured in the load measurement step for that tooth 106a. In the damage rate estimation step, the damage rate of each of the multiple teeth 106a (e.g., teeth 106a-1 to 106a-M) may be calculated from the accumulated data of the applied load measured in the load measurement step for each of the multiple teeth 106a.

[0098] In the damage rate display step, information regarding the damage rate calculated in the damage rate estimation step is displayed on the display unit 45. In the damage rate estimation step, the display unit 45 may display the damage rate and average load value of the teeth 106a of the ring gear 106. In the damage rate estimation step, the display unit 45 may display a graph showing the damage rate values ​​of each of the multiple teeth 106a (teeth 106a-1 to 106a-M), as shown in Figure 6.

[0099] The warning process is performed when the damage rate calculated in the damage rate estimation process is equal to or greater than a standard value. In the warning process, a warning is issued. The warning issued in the warning process is a warning that the calculated damage rate is equal to or greater than a standard value. For example, the warning process can be performed using a computer connected to an IoT device installed on the wind turbine 10 of the damage rate estimation system 200 described above. The warning process may also be performed using a display unit 45. In this case, the warning can be issued in the warning process by displaying a warning on the display unit 45 that the calculated damage rate is equal to or greater than a standard value. Although not shown in the figures, the computer connected to the IoT device installed on the wind turbine 10 may further have a speaker unit that emits sound. In this case, the warning can be issued in the warning process by having the speaker unit emit a sound or voice that conveys a warning that the calculated damage rate is equal to or greater than a standard value.

[0100] According to the damage rate estimation system 200 and damage rate monitoring method of this embodiment, the damage rate of the teeth 106a of the ring gear 106 can be calculated. In particular, the damage rate of each of the multiple teeth 106a of the ring gear 106 can be calculated. According to the damage rate estimation system 200 and damage rate monitoring method of this embodiment, the damage rate of the teeth 106a can be grasped in real time in the wind turbine 10 while it is in operation and used for controlling the wind turbine 10 and for maintenance of the ring gear 106.

[0101] According to the damage rate monitoring method using the damage rate estimation system 200 of this embodiment, it becomes easy to repeatedly calculate the damage rate. It also becomes easy to perform this calculation periodically.

[0102] In the ring gear 106 of the movable part 11 of the wind turbine 10, depending on the environment in which the wind turbine 10 is installed, some of the teeth 106a may experience a higher rate of damage. For example, if the wind turbine 10 is installed in an environment where it is prone to wind from a specific direction, some of the teeth 106a may experience a higher rate of damage. In such cases, the damage rate of each of the teeth 106a can be determined and used for controlling the wind turbine 10 and maintaining the ring gear 106. For example, if only some of the teeth 106a have a higher rate of damage, the condition of the tooth surface of only the teeth 106a with the higher rate of damage can be checked, and if necessary, only the teeth 106a with the higher rate of damage can be repaired by welding or other means. If the ring gear 106 is a segmented ring gear, the ring gear 106 can be segmented, and only the part containing the teeth 106a with the higher rate of damage can be replaced.

[0103] As a comparative example, consider the following method for checking the condition of the teeth 106a of the ring gear 106 and performing maintenance. In the comparative example method, the applied load is not measured in particular, as in this embodiment. When a malfunction of the movable part 11 is discovered, the condition of the tooth surfaces of all the teeth 106a of the ring gear 106 is checked, and the damaged teeth 106a are identified. According to the comparative example method described above, the damaged teeth 106a cannot be identified unless the condition of the tooth surfaces of all the teeth 106a of the ring gear 106 is checked. Therefore, it takes a long time to identify the damaged teeth 106a. In addition, according to the comparative example method described above, the condition of the tooth surfaces of the teeth 106a cannot be checked unless the damage to the teeth 106a has progressed to the extent that a malfunction of the movable part 11 is discovered. For this reason, it is not possible to notice early that the rate of tooth damage 106a is increasing. Therefore, by the time tooth damage 106a is noticed, the ring gear 106 may be in a state where it cannot be repaired by repairing only specific teeth 106a. Therefore, repairing the movable part 11 may require replacing the entire ring gear 106. In this case, the cost of repairing the movable part 11 will be high.

[0104] In contrast, the damage rate estimation system 200 and damage rate monitoring method of this embodiment allow for maintenance of the ring gear 106 by checking the tooth surface condition of only the teeth 106a with high damage rates. Furthermore, it is possible to detect early on when the damage rate of teeth 106a is increasing. Therefore, maintenance can be completed by identifying the teeth 106a with increasing damage rates at a stage where replacement of the entire ring gear 106 is not necessary, and repairing only those teeth 106a. As a result, the time required for maintenance can be shortened and costs can be reduced.

[0105] Furthermore, according to the damage rate monitoring method of this embodiment, the warning step can alert the manager of the wind turbine 10 that the damage rate of the teeth 106a of the ring gear 106 is above a standard value. This allows the manager to take early action to suppress damage to the teeth 106a, such as controlling the wind turbine 10 or performing maintenance on the ring gear 106.

[0106] Next, the life prediction system 201 of this embodiment will be described. The life prediction system 201 of this embodiment comprises the damage rate estimation system 200 of this embodiment described above and a life prediction unit 46. In the example shown in Figure 5, the life prediction unit 46 is included in the calculation unit 40. The life prediction unit 46 predicts the life of the teeth 106a of the ring gear 106 based on the damage rate of the teeth 106a of the ring gear 106 calculated by the damage rate estimation system 200.

[0107] The life prediction unit 46 of this embodiment calculates the predicted lifespan L of the teeth 106a of the ring gear 106 based on the elapsed time T from the initial state time H to the calculation time G for calculating the damage rate R, and the damage rate R, using the following formula (1).

number

[0108] The life prediction unit 46 of this embodiment may predict the lifespan of one tooth 106a of the ring gear 106 based on the damage rate of that tooth 106a. Alternatively, the life prediction unit 46 may predict the lifespan of each of the multiple teeth 106a of the ring gear 106 based on the damage rate of each of the multiple teeth 106a.

[0109] In the life prediction system 201 of this embodiment, the display unit 45 may display information regarding the lifespan of the teeth 106a predicted by the life prediction unit 46. The display unit 45 may display the lifespan value for one tooth 106a of the ring gear 106. The display unit 45 may display the lifespan values ​​for multiple teeth 106a of the ring gear 106.

[0110] Next, the life prediction method of this embodiment will be described. The life prediction method of this embodiment can be performed using the life prediction system 201 of this embodiment described above. The life prediction method of this embodiment comprises a load measurement step, a damage rate estimation step, and a life prediction step. The life prediction method may further include a life display step.

[0111] The load measurement process and the damage rate estimation process can be carried out in the same manner as the load measurement process and the damage rate estimation process described in the damage rate monitoring method described above.

[0112] In the life prediction process, the life of the teeth 106a of the ring gear 106 is predicted based on the damage rate of the teeth 106a of the ring gear 106 calculated in the damage rate estimation process.

[0113] In the life prediction process, information regarding the lifespan of the tooth 106a predicted in the life prediction process is displayed on the display unit 45.

[0114] According to the life prediction system 201 and life prediction method of this embodiment, the lifespan of the teeth 106a of the ring gear 106 can be predicted. In particular, the lifespan of each of the multiple teeth 106a of the ring gear 106 can be predicted. According to the life prediction system 201 and life prediction method of this embodiment, the lifespan of the teeth 106a can be determined in the wind turbine 10 while it is in operation and used for controlling the wind turbine 10 and for maintaining the ring gear 106. In particular, the predicted lifespan of the teeth 106a can be used in formulating a long-term maintenance plan.

[0115] As described above, one embodiment has been explained with reference to specific examples, but the above-mentioned example is not intended to limit this embodiment. The above-described embodiment can be implemented in various other examples, and various omissions, substitutions, and modifications can be made without departing from its essence.

[0116] An example of modification will be described below with reference to the drawings. In the following explanation and the drawings used therein, parts that can be configured in the same way as in the specific example described above will be given the same reference numerals as those used for the corresponding parts in the specific example described above, and redundant explanations will be omitted.

[0117] (Variation 1) In the above-described embodiment, a position identification unit 42 was described that identifies the target tooth 106b from sensor information and position information of the pinion 34 relative to the driven part 103a. However, the means by which the position identification unit 42 identifies the target tooth 106b to which the applied load is applied from among the multiple teeth 106a of the ring gear 106 is not limited to this.

[0118] The position identification unit 42 of the modified example 1 identifies the target tooth 106b at the second time t2 based on the position information of the pinion 34 relative to the ring gear 106 at the first time t1 and the rotation amount information of the pinion 34 between the first time t1 and the second time t2.

[0119] As an example, the position information of the pinion 34 relative to the ring gear 106 at the first time step t1 is stored in advance in a location accessible to the position identification unit 42, for example, in the memory unit mentioned above.

[0120] As an example, the load measurement system 1 of Modification 1 further includes a rotation amount sensor (not shown) that acquires rotation amount information of the shaft 33. The rotation amount sensor is, for example, an encoder. In this case, the position identification unit 42 uses the rotation amount information of the shaft 33 acquired by the rotation amount sensor as rotation amount information. The pinion 34 is fixed to the end of the shaft 33 and rotates in accordance with the rotation of the shaft 33. For this reason, the rotation amount information of the shaft 33 can be considered as the rotation amount information of the pinion 34. One of the rotation directions of the pinion 34 from which the rotation amount information is acquired by the rotation amount sensor is referred to as the pinion first side, and the other side as the pinion second side. Let's consider the case where, between the first time t1 and the second time t2, the pinion 34 rotates only 3 times on the pinion first side and only 2 times on the pinion second side. In this case, the position identification unit 42, referring to the rotation amount information acquired by the rotation amount sensor, determines that the position of the pinion 34 relative to the ring gear 106 at the second time t2 has changed from the position of the pinion 34 relative to the ring gear 106 at the first time t1 by the amount by which the pinion 34 rotates once toward the first pinion side. As a result, the position identification unit 42 of the modified example 1 can identify the position of the pinion 34 relative to the ring gear 106 and identify the target tooth 106b at the second time t2, even if the second time t2 is any time other than the first time t1.

[0121] The load measurement system 1 equipped with the position identification unit 42 of the modified example 1 can also measure which of the multiple teeth 106a of the ring gear 106 is being subjected to what degree of applied load.

[0122] (Modification 2) In the embodiments and modifications described above, a load detection unit 41 that handles the first side load and the second side load without distinction has been described. However, the configuration of the load detection unit 41 is not limited thereto.

[0123] In the modified example 2, the load detection unit 41 distinguishes and detects two loads: one applied to the teeth 106a of the ring gear 106 when the teeth of the pinion 34 are in contact with the teeth of the ring gear 106 from the first side SR1 in the circumferential direction DR of the ring gear 106, and the other applied to the teeth 106a of the ring gear 106 when the teeth of the pinion 34 are in contact with the teeth of the ring gear 106 from the second side SR2, and the other applied to the teeth 106a of the ring gear 106, and the other applied to the teeth

[0124] In the damage rate estimation system 200 equipped with the load detection unit 41 of Modified Example 2, the damage rate estimation unit 44 may separately calculate the damage rate related to the first side load applied to the teeth 106a of the ring gear 106 and the damage rate related to the second side load applied to the teeth 106a of the ring gear 106. The damage rate estimation unit 44 may separately calculate the average load related to the first side load applied to the teeth 106a of the ring gear 106 and the average load related to the second side load applied to the teeth 106a of the ring gear 106. In the life prediction system 201 equipped with the load detection unit 41 of Modified Example 2, the life prediction unit 46 may separately perform life prediction based on the damage rate related to the first side load applied to the teeth 106a of the ring gear 106 and life prediction based on the damage rate related to the second side load applied to the teeth 106a of the ring gear 106.

[0125] According to the load detection unit 41 of Modification 2, the first side load and the second side load can be distinguished, and the damage rate and average load can be calculated separately, and the lifespan can be predicted separately. Therefore, by taking into account the difference between the first side load and the second side load, it is possible to calculate a damage rate and average load that are more in line with the actual situation, and to make a lifespan prediction that is more in line with the actual situation.

[0126] (Variation 3) In the embodiments and modifications described above, a load measurement system 1 was described that measures the applied load on the teeth 106a of the ring gear 106 of the movable part 11 that rotates the nacelle 103 of the wind turbine 10 relative to the tower 102. However, the form of the movable part having the ring gear 106 that the load measurement system 1 is subject to measurement of applied load is not limited to this.

[0127] In Modification 3, we focus on the movable part 111 of the wind turbine 10 shown in Figure 1, which rotates the rotor 104 and blades 105 relative to the nacelle 103. The rotor 104 and blades 105 rotate in the roll direction relative to the nacelle 103. Although not shown, the movable part 111, like the movable part 11 described above, has a ring gear having multiple teeth and a drive device having a pinion that meshes with the ring gear. In this case, the ring gear of the movable part 111 may be provided on the nacelle 103, and the drive device of the movable part 111 may be provided on the rotor 104. That is, the rotor 104 may correspond to the driven part of the movable part 111. The ring gear of the movable part 111 may be provided on the rotor 104, and the drive device of the movable part 111 may be provided on the nacelle 103. That is, the nacelle 103 may correspond to the driven part of the movable part 111. As long as there is no contradiction, the description of the ring gear 106 and drive unit 3 of the movable part 11 can be applied to the description of the ring gear and drive unit 11 of the movable part 111.

[0128] For example, the number of drive devices in the movable part 111 is one.

[0129] With regard to the ring gear of the movable part 111, similar to the ring gear 106 of the movable part 111, the load measurement system 1 and load measurement method described above can be used to measure which of the multiple teeth of the ring gear is being subjected to what degree of applied load. Furthermore, the damage rate estimation system 200 and damage rate monitoring method described above can be used to calculate the damage rate of the teeth of the ring gear. In addition, the lifespan prediction system 201 and lifespan prediction method described above can be used to predict the lifespan of the teeth of the ring gear.

[0130] The embodiments of the present invention are not limited to the individual embodiments described above, but also include various modifications that a person skilled in the art could conceive, and the effects of the present invention are not limited to those described above. In other words, various additions, modifications, and partial deletions are possible as long as they do not depart from the conceptual idea and spirit of the present invention derived from the claims and their equivalents. [Explanation of Symbols]

[0131] 1. Load Measurement System 3. Drive unit 10 windmill 11 Moving parts 20 Strain Sensors 21 Drive current sensor 22 Operation Monitor 23 Brake current sensor 34 pinion 41 Load detection unit 42 Location identification part 44 Damage rate estimation section 46 Life Prediction Unit 102 Tower 103 Nacer 103a Driven part 106 Ring Gear 106a Teeth 106b Target teeth 111 Moving parts 200 Damage Rate Estimation System 201 Life Prediction System

Claims

1. A movable part of a wind turbine having a ring gear having multiple teeth and a drive device having a pinion that meshes with the ring gear, wherein a load detection unit detects the applied load on the teeth of the ring gear when the driving force or external force of the drive device is applied via the pinion while the ring gear is meshed with the pinion, A load measurement system comprising: a positioning unit that identifies a target tooth to which the applied load is applied from among the plurality of teeth of the ring gear.

2. As the movable part is driven, the driven part to which the drive device having the pinion is attached rotates relative to the ring gear. The load measurement system according to claim 1, wherein the position identification unit identifies the target tooth to which the applied load is applied from among the plurality of teeth of the ring gear, based on sensor information obtained from a sensor that detects the rotational position of the driven part with respect to the ring gear and position information of the pinion with respect to the driven part.

3. The load measurement system according to claim 1, wherein the position identification unit identifies, at the second time, from among the plurality of teeth of the ring gear, the target tooth to which the applied load is applied, based on the position information of the pinion relative to the ring gear at the first time and the amount of rotation information of the pinion between the first time and the second time.

4. The load detection unit distinguishes and detects the applied load on the teeth of the ring gear when the teeth of the pinion are in contact with the teeth of the ring gear from the first side in the circumferential direction of the ring gear, and the driving force or external force of the drive device is applied via the pinion, and the applied load on the teeth of the ring gear when the teeth of the pinion are in contact with the teeth of the ring gear from the second side, which is opposite to the first side in the circumferential direction, and the driving force or external force of the drive device is applied via the pinion, the load detection unit distinguishes and detects the applied load on the teeth of the ring gear.

5. The movable part rotates the nacelle of the wind turbine relative to the tower. The load measuring system according to claim 1, wherein the movable part has a plurality of the drive devices.

6. A load measurement system according to any one of claims 1 to 5, A damage rate estimation system comprising: a damage rate estimation unit that calculates the damage rate of the teeth of the ring gear from the applied load on the teeth of the ring gear measured within a certain period of time by the load measurement system.

7. The damage rate estimation system according to claim 6, wherein the damage rate estimation unit calculates an average load from the applied load on the teeth of the ring gear measured within a certain period of time by the load measurement system, and uses the average load to calculate the damage rate of the teeth of the ring gear.

8. The damage rate estimation system according to claim 6, A life prediction system comprising: a life prediction unit that predicts the lifespan of the teeth of the ring gear based on the damage rate of the teeth of the ring gear calculated by the damage rate estimation system.

9. In a movable part of a wind turbine having a ring gear having multiple teeth and a drive device having a pinion that meshes with the ring gear, a load detection step is performed to detect the applied load on the teeth of the ring gear when the driving force or external force of the drive device is applied via the pinion while the ring gear is meshed with the pinion. A load measurement method comprising: a positioning step of identifying a target tooth to which the applied load is applied from among the plurality of teeth of the ring gear.

10. A load measurement step of measuring the applied load on the teeth of the ring gear within a certain period of time using the load measurement method described in claim 9, A damage rate estimation step, which calculates the damage rate of the teeth of the ring gear from the applied load on the teeth of the ring gear measured within a certain period of time in the load measurement step, A damage rate monitoring method comprising: a warning step of issuing a warning if the damage rate calculated in the damage rate estimation step is equal to or greater than a standard value.

11. A computer provides a load detection step for detecting the applied load on the teeth of a wind turbine having a ring gear having multiple teeth and a drive device having a pinion that meshes with the ring gear, when the drive device or an external force is applied to the teeth of the ring gear via the pinion while the ring gear is meshed with the pinion. A program for causing a load measurement method to be executed, which includes a positioning step of identifying a target tooth to which the applied load is applied from among the plurality of teeth of the ring gear.

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