Anomaly detection system and anomaly detection method for wind power generation equipment.

Abstract

To provide an abnormality diagnosis system for wind power generation equipment which can early detect an abnormality of a hydraulic accumulator, and an abnormality diagnosis method.SOLUTION: An abnormality diagnosis system for wind power generation equipment for diagnosing an abnormality of the wind power generation equipment having a hydraulic blade pitch mechanism comprises: a pitch angle determination part for determining whether or not a pitch angle abnormality condition that a pitch angle of a winding blade reaches a fine-side pitch angle rather than a regulation pitch angle at timing at which the hydraulic pressure of the hydraulic accumulator is dropped down to a first regulation pressure value in a first accumulator operation test mode of the wind power generation equipment in which the drive of a pump motor is stopped in a state that the windmill blade is arranged in a fine position, and the windmill blade is moved toward a feather position by a working fluid which is discharged from the hydraulic accumulator is satisfied; and a first accumulator abnormality diagnosis part for diagnosing the existence of an abnormality in the hydraulic accumulator when it is determined that the pitch angle abnormality condition is satisfied.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to an abnormality diagnosis system for a wind power generation facility for performing an abnormality diagnosis of a wind power generation facility, and an abnormality diagnosis method.

Background Art

[0002] The wind power generation facility disclosed in Patent Document 1 includes a hydraulic supply device that supplies hydraulic oil to a hydraulic actuator, and a hydraulic accumulator installed in a hydraulic circuit that constitutes the hydraulic supply device. In the same document, based on the gas pressure of the hydraulic accumulator, it is determined whether there is an abnormality in the hydraulic accumulator. Specifically, if the gas pressure of the hydraulic accumulator after the hydraulic pump stops falls below a pressure threshold value after a specified time has elapsed, it is determined that there is an abnormality in the pressure accumulation function because the decrease in the gas pressure of the hydraulic accumulator is significant.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is desirable to detect an abnormality in a hydraulic accumulator at an early stage.

[0005] An object of the present disclosure is to provide an abnormality diagnosis system for a wind power generation facility and an abnormality diagnosis method that can detect an abnormality in a hydraulic accumulator at an early stage.

Means for Solving the Problems

[0006] An abnormality diagnosis system for a wind power generation facility according to at least one embodiment of the present disclosure is an abnormality diagnosis system for a wind power generation facility for performing an abnormality diagnosis of a wind power generation facility including a hydraulic blade pitch mechanism, In the first accumulator operation test mode of the wind power generation equipment, in which the pump motor is stopped when the wind turbine blades are positioned in the fine position and the wind turbine blades are moved toward the feather position by the hydraulic fluid released from the hydraulic accumulator, a pitch angle determination unit is provided to determine whether the pitch angle abnormality condition is met, in which the pitch angle of the wind turbine blades at the timing when the hydraulic pressure of the hydraulic accumulator drops to a first specified pressure value is a pitch angle that is finer than the specified pitch angle, If it is determined that the above pitch angle abnormality condition is met, a first accumulator abnormality diagnosis unit for diagnosing that there is an abnormality in the hydraulic accumulator, It is equipped with.

[0007] An abnormality diagnosis method for wind power generation equipment according to at least one embodiment of the present disclosure is: An abnormality diagnosis method for wind power generation equipment equipped with a hydraulic blade pitch mechanism, In a first accumulator operation test mode of the wind power generation equipment, in which the pump motor is stopped while the wind turbine blades are positioned in the fine position, and the wind turbine blades are moved toward the feather position by the hydraulic fluid released from the hydraulic accumulator, a pitch angle determination step is made to determine whether a pitch angle abnormality condition is met, in which the pitch angle of the wind turbine blades at the timing when the hydraulic pressure of the hydraulic accumulator drops to a first specified pressure value is a pitch angle that is finer than the specified pitch angle, If it is determined that the above-mentioned pitch angle abnormality condition is met, a first accumulator abnormality diagnosis step is performed to diagnose that there is an abnormality in the hydraulic accumulator, It is equipped with. [Effects of the Invention]

[0008] This disclosure provides an anomaly diagnosis system and an anomaly diagnosis method for wind power generation equipment that can detect abnormalities in a hydraulic accumulator at an early stage. [Brief explanation of the drawing]

[0009] [Figure 1]This is a schematic diagram showing an abnormality diagnosis system and wind power generation equipment according to one embodiment. [Figure 2] This is a schematic diagram showing the hardware configuration of an anomaly diagnosis system according to one embodiment. [Figure 3] This is a schematic diagram showing a hydraulic blade pitch mechanism and oil supply unit according to one embodiment. [Figure 4] This is a schematic diagram showing a hydraulic accumulator according to one embodiment. [Figure 5] This is a schematic graph showing an example of time-series data for pitch angle and oil supply pressure in the first accumulator operation test mode. [Figure 6] This is a schematic block diagram showing the functional configuration of an abnormality diagnosis system according to one embodiment. [Figure 7] This is a schematic graph showing an example of time-series data for pitch angle and oil supply pressure in the second accumulator operation test mode. [Figure 8] This is another schematic block diagram showing the functional configuration of an abnormality diagnosis system according to one embodiment. [Figure 9] This is a flowchart showing the accumulator operation test process according to one embodiment. [Figure 10] This flowchart shows a high-frequency anomaly diagnosis process according to one embodiment. [Figure 11] This flowchart shows the low-frequency anomaly diagnosis process according to one embodiment. [Modes for carrying out the invention]

[0010] Hereinafter, several embodiments of this disclosure will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described or shown in the drawings as embodiments are not intended to limit the scope of the invention, but are merely illustrative examples. For example, expressions indicating relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" shall not only precisely represent such arrangements, but also represent states where there are tolerances or relative displacements with angles or distances that can achieve the same function. For example, expressions indicating that things are in an equal state such as "identical", "equal", and "homogeneous" shall not only precisely represent an equal state, but also represent states where there are tolerances or differences that can achieve the same function. For example, expressions representing shapes such as a rectangular shape or a cylindrical shape shall not only represent the shapes such as a rectangular shape or a cylindrical shape in a geometrically precise sense, but also represent shapes including concave and convex portions, chamfered portions, etc. within a range where the same effect can be obtained. On the other hand, expressions such as "comprising", "having", "including", or "possessing" a certain component are not exclusive expressions that exclude the existence of other components.

[0011] <1. Overview of the Abnormality Diagnosis System 40 and the Wind Power Generation Facility 1> FIG. 1 is a schematic diagram showing an abnormality diagnosis system 40 and a wind power generation facility 1 according to an embodiment of the present disclosure. The abnormality diagnosis in this document includes determining whether there is an abnormality in the wind power generation facility 1. As shown in FIG. 1, the wind power generation facility 1 includes a support column 2 erected on a foundation or the like, a nacelle 3 installed at the upper end of the support column 2, and a windmill rotor 4 rotatably provided on one end side of the nacelle 3. The windmill rotor 4 includes a rotor head 5 and a plurality of windmill blades 6 radially attached to the rotor head 5.

[0012] Inside the nacelle 3, a generator 11 connected to the windmill rotor 4 via a speed increaser 10 is installed. By transmitting the rotation of the windmill rotor 4 to the generator 11 via the speed increaser 10 to drive the generator 11, electric power is output from the generator 11.

[0013] Furthermore, the wind power generation equipment 1 includes a hydraulic blade pitch mechanism 12 for adjusting the pitch angle of each wind turbine blade 6, and a yaw rotation mechanism 14 for adjusting the yaw angle of the nacelle 3. The hydraulic blade pitch mechanism 12 is configured to move the wind turbine blade 6 between a feather position and a fine position in accordance with the supply of hydraulic fluid. Details of the configuration of the hydraulic blade pitch mechanism 12 will be described later. The yaw rotation mechanism 14 includes a yaw motor 16, a nacelle gear for rotating integrally with the nacelle 3, and at least one gear connected to the nacelle gear and the yaw motor 16. When the yaw motor 16 is driven, the nacelle 3 rotates in the yaw direction.

[0014] The wind power generation equipment 1 includes an anemometer 7 for measuring the wind speed of the wind passing through the wind power generation equipment 1, an anemometer 8 for measuring the wind direction of the wind passing through the wind power generation equipment 1, a thermometer 9 for measuring the temperature, a pitch angle sensor 15 for measuring the pitch angle, and a yaw angle sensor 18 for measuring the yaw angle of the nacelle 3. The anemometer 7, anemometer 8, and thermometer 9 are installed on the outer surface of the nacelle 3 (for example, the top of the nacelle 3). The anemometer 7 may be, for example, a cup type or a windmill type anemometer. A cup type anemometer measures wind speed by measuring the rotation speed of a cup that rotates around a rotating shaft using a rotary encoder or the like, while a windmill type anemometer measures wind speed by measuring the rotation speed of a propeller-shaped blade that rotates around a rotating shaft using a rotary encoder or the like. The wind vane 8 may be a potentiometer-type wind vane that converts changes in the direction of a rotating vane around a rotation axis into changes in electrical resistance, for example, by measuring the angle that the direction of the wind flow makes with a predetermined reference direction (e.g., north) as the wind direction. The pitch angle sensor 15 may be any type of sensor, for example, a magnetic displacement sensor equipped with a Hall element. The yaw angle sensor 18 measures the angle that the rotation axis of the wind turbine rotor 4 makes with the predetermined reference direction as the yaw angle of the nacelle 3.

[0015] A control device 20 for performing various operational controls of the wind power generation equipment 1 is provided in an appropriate location on the wind power generation equipment 1 (for example, inside the nacelle 3 or inside the support column 2). The control device 20 receives signals indicating the wind speed measured by the anemometer 7, the wind direction measured by the wind vane 8, the temperature measured by the thermometer 9, the pitch angle measured by the pitch angle sensor 15, and the yaw angle of the nacelle 3 measured by the yaw angle sensor 18. Furthermore, the control device 20 receives the detection result of a hydraulic pressure detection unit 17, which detects the hydraulic pressure of the hydraulic fluid supplied to the hydraulic blade pitch mechanism 12, as a signal. Details of the hydraulic pressure detection unit 17 will be described later. The control device 20 is at least one controller.

[0016] The control device 20 is configured to communicate with the anomaly diagnosis system 40 via the communication network 21. The control device 20 transmits data to the anomaly diagnosis system 40 that represents signals acquired by the wind power generation equipment 1, such as wind speed measured by the anemometer 7, wind direction measured by the wind vane 8, temperature measured by the thermometer 9, pitch angle measured by the pitch angle sensor 15, yaw angle measured by the yaw angle sensor 18, and detection results from the hydraulic detection unit 17. The anomaly diagnosis system 40 stores the data transmitted from the control device 20 and uses it to diagnose anomalies in the wind power generation equipment 1 as described later.

[0017] Figure 2 is a schematic diagram showing the hardware configuration of an anomaly diagnosis system 40 according to one embodiment of the present disclosure. The anomaly diagnosis system 40 is configured using a computer that includes, for example, a processor 72, RAM (Random Access Memory) 74, ROM (Read Only Memory) 76, HDD (Hard Disk Drive) 78, input I / F 80, output I / F 82, and display 83, all of which are connected to each other via a bus 84. The hardware configuration of the anomaly diagnosis system 40 is not limited to the above and may be realized by a combination of a control circuit and a storage device. The anomaly diagnosis system 40 is also configured by a computer executing a program that realizes each function of the anomaly diagnosis system 40. The functions of each part of the anomaly diagnosis system 40 described below are realized by the processor 72 loading a program stored in ROM 76 into RAM 74 and executing it. The processor 72 may temporarily store various data generated in conjunction with the execution of the program in RAM 74. The hardware comprising the anomaly diagnosis system 40 may be centralized in one location or distributed across multiple locations. The following example describes a case where the anomaly diagnosis system 40 is located away from the wind power generation equipment 1 and performs remote anomaly diagnosis of the wind power generation equipment 1. However, at least one function of the anomaly diagnosis system 40 may be implemented, for example, by a control device 20 provided by the wind power generation equipment 1.

[0018] <2. Configuration of the hydraulic blade pitch mechanism 12 and oil supply unit 60> Figure 3 is a schematic diagram showing a hydraulic blade pitch mechanism 12 and an oil supply unit 60 for supplying hydraulic fluid as a power source to the hydraulic blade pitch mechanism 12. For the sake of simplicity, only one wind turbine blade 6 is shown in Figure 3, illustrating the configuration for changing the pitch angle of the wind turbine blade 6. Regardless of the number of wind turbine blades 6, the principle for changing the pitch angle of the wind turbine blade 6 is the same.

[0019] The hydraulic blade pitch mechanism 12 is configured to move the wind turbine blade 6 between a feather position and a fine position. Specifically, the hydraulic blade pitch mechanism 12 includes a hydraulic cylinder 22 and a pitch link mechanism 26 connected to the hydraulic cylinder 22 and the wind turbine blade 6. The hydraulic cylinder 22 includes a cylinder 23, a piston 24 that separates the cylinder 23 into a first chamber 23A and a second chamber 23B, and a piston rod 25 connected to the piston 24 and the pitch link mechanism 26. The pitch link mechanism 26 is configured to convert the linear motion of the piston rod 25 into rotational force of the wind turbine blade 6, and this rotational force changes the pitch angle of the wind turbine blade 6. Although not shown in detail, the pitch link mechanism 26 may include a first link rotatably connected to the piston 24 and a second link rotatably connected to the wind turbine blade 6. The first and second links are rotatably connected.

[0020] The oil supply unit 60 includes an oil tank 61 for storing hydraulic fluid, a supply line 62 provided between the oil tank 61 and the hydraulic cylinder 22, and a hydraulic valve 85 provided in the supply line 62. The supply line 62 is configured to guide the hydraulic fluid to the hydraulic cylinder 22 of the hydraulic blade pitch mechanism 12.

[0021] The hydraulic valve 85, acting as an electromagnetic valve, has four ports, including ports A, B, P, and T. The supply line 62 includes a first line 101 connected to the first chamber 23A and port A, a second line 102 connected to the second chamber 23B and port B, and a main line 103 connected to port P and the oil tank 61. Furthermore, port T and the oil tank 61 are connected via a return line 68 for returning the hydraulic fluid to the oil tank 61. The main line 103 is equipped with a pump motor 63 for supplying the hydraulic fluid stored in the oil tank 61 to the hydraulic cylinder 22. The pump motor 63 is configured to be driven in response to control commands sent from the control device 20.

[0022] A hydraulic valve 85 positioned between the pump motor 63 and the hydraulic cylinder 22 is configured to switch the destination of the hydraulic fluid flowing through the main line 103 to either the first chamber 23A or the second chamber 23B. Specifically, the hydraulic valve 85 is supplied with a servo current as a control command, and the connection state of each port of the hydraulic valve 85 is switched according to this control command. When port A and port P are connected and port B and port T are connected, the hydraulic fluid supplied from the main line 103 is supplied to the first chamber 23A via the first line 101. In this case, the wind turbine blade 6 moves toward the feather position due to the straight-line movement of the piston 24, and the hydraulic fluid discharged from the second chamber 23B flows sequentially through the second line 102 and the return line 68 and is returned to the oil tank 61. On the other hand, when port A and port T are connected and port B and port P are connected, the destination of the hydraulic fluid is switched to the second chamber 23B. In this case, the straight-line movement of the piston 24 causes the wind turbine blade 6 to move toward the fine position, and the hydraulic fluid discharged from the first chamber 23A returns to the oil tank 61.

[0023] The oil supply unit 60 further includes a hydraulic accumulator 65 for storing emergency hydraulic fluid. For example, if the operation of the wind power generation equipment 1 is suddenly stopped due to a power outage, the hydraulic accumulator 65 is configured to release hydraulic fluid into the main line 103. When the hydraulic fluid released into the main line 103 is supplied to the first chamber 23A and the wind turbine blades 6 move to the feather position, it is possible to prevent the wind turbine blades 6 from rotating without being under the control of the control device 20 while the wind power generation equipment 1 is stopped. In the event of a sudden shutdown of the wind power generation equipment 1, the connection state of the hydraulic valve 85 is configured so that hydraulic fluid flows from the main line 103 to the first line 101 and from the second line 102 to the return line 68.

[0024] Figure 4 is a schematic diagram showing a hydraulic accumulator 65 according to one embodiment of the present disclosure. The hydraulic accumulator 65 has an accumulator container 66 for storing emergency hydraulic fluid and a bladder 67 housed inside the accumulator container 66. The accumulator container 66 is in communication with the main line 103 (see Figure 3). The bladder 67 is a rubber balloon filled with a gas such as nitrogen.

[0025] The principle by which the hydraulic accumulator 65 releases emergency hydraulic fluid into the main line 103 is as follows: The hydraulic pressure in the accumulator container 66 is approximately equal to the hydraulic pressure in the main line 103 (see Figure 3). While the wind power generation equipment 1 is operating normally, the hydraulic pressure in the main line 103 is maintained at a relatively high level by the drive of the pump motor 63, and emergency hydraulic fluid is stored in the accumulator container 66. At this time, the bladder 67 remains contracted so that the relatively high hydraulic pressure in the accumulator container 66 and the gas pressure of the bladder 67 are in equilibrium. If the operation of the wind power generation equipment 1 suddenly stops, the drive of the pump motor 63 stops, and the hydraulic pressure in the main line 103 decreases. The hydraulic pressure in the accumulator container 66 falls significantly below the gas pressure of the bladder 67, causing the bladder 67 to expand, and as a result, emergency hydraulic fluid is released from the accumulator container 66 into the main line 103. As the released hydraulic fluid is supplied to the hydraulic cylinder 22, both the hydraulic pressure in the main line 103 and the hydraulic pressure in the hydraulic accumulator 65 decrease.

[0026] Returning to Figure 3, a hydraulic pressure detection unit 17 is located on the main line 103. In one embodiment of the present disclosure, the hydraulic pressure detection unit 17 is a pressure switch configured to output different signals depending on whether the hydraulic pressure in the main line 103 is below a first specified pressure value. The output signal of the pressure switch switches from either an ON signal or an OFF signal to the other when the hydraulic pressure falls below the first specified pressure value. If almost all of the hydraulic fluid stored in the hydraulic accumulator 65 is supplied normally to the hydraulic cylinder 22, the hydraulic pressure in the main line 103 is expected to be below the first specified pressure value. In other words, the hydraulic pressure in the hydraulic accumulator 65 is expected to be below the first specified pressure value. The signal from the hydraulic pressure detection unit 17 is sent from the hydraulic pressure detection unit 17 to the control device 20. The control device 20 transmits data indicating the output signal from the hydraulic pressure detection unit 17 to the abnormality diagnosis system 40. The data transmitted to the abnormality diagnosis system 40 is used for abnormality diagnosis of the wind power generation equipment 1 (details will be described later). The first specified pressure value may, for example, be 75% or less of the rated pressure of the hydraulic accumulator 65, or 50% or less.

[0027] If there is any abnormality in the hydraulic accumulator 65 due to aging or other reasons, there is a risk that the wind turbine blades 6 may not return to the feather position after the operation of the wind power generation equipment 1 is stopped. One example of an abnormality is a decrease in the gas pressure in the bladder 67. If the gas pressure in the bladder 67 drops to a certain level, the bladder 67 cannot expand sufficiently when the hydraulic accumulator 65 is activated, and the hydraulic fluid is not sufficiently released from the hydraulic accumulator 65. Another example of an abnormality is damage to the bladder 67. Damage such as cracks in the bladder 67 does not significantly affect the pressure accumulation function of the bladder 67 when the bladder 67 is contracted. However, during the process in which the bladder 67 expands due to the operation of the hydraulic accumulator 65, gas leaks from the bladder 67, and the hydraulic fluid is not released from the hydraulic accumulator 65. In this case, the bladder 67 cannot expand sufficiently, and the hydraulic fluid is not sufficiently released from the hydraulic accumulator 65.

[0028] Therefore, in one embodiment of the present disclosure, an operating test mode is provided as an operating mode for the wind power generation equipment 1, which allows the abnormality diagnosis system 40 to determine whether there is any abnormality in the hydraulic accumulator 65. The operating mode of the wind power generation equipment 1 is configured to periodically switch from a normal operating mode to match the amount of power generated by the wind power generation equipment 1 to a target value to an operating test mode. The switching of the operating mode is performed by the control device 20. Data indicating various signals input to the control device 20 during operation in the operating test mode is sent to the abnormality diagnosis system 40 and used for abnormality diagnosis of the hydraulic accumulator 65 and other components. The operating test mode as an operating mode for the wind power generation equipment 1 includes a first accumulator operating test mode and a second accumulator operating test mode.

[0029] <3. First Accumulator Operation Test Mode> Referring to Figures 5 and 6, the first accumulator operation test mode and the functional configuration of the abnormality diagnosis system 40 for performing abnormality diagnosis in the first accumulator operation test mode will be explained.

[0030] <3-1. Details of the operational test> Figure 5 is a schematic graph showing time-series data of pitch angle and oil supply pressure in the first accumulator operation test mode. The oil supply pressure is the hydraulic pressure in the main line 103 and can be considered to be approximately equal to the hydraulic pressure in the accumulator container 66. The horizontal axis of the graph represents time. The vertical axis on the left represents the pitch angle, θ. fi θ is the pitch angle corresponding to the fine position. fe This represents the pitch angle corresponding to the feather position. The vertical axis on the right shows the oil supply pressure.

[0031] In the first accumulator operation test mode, the pump motor 63, hydraulic accumulator 65, and hydraulic valve 85 are operated to move the wind turbine blade 6 from the fine position to the feather position. Specifically, the hydraulic cylinder 22 moves the wind turbine blade 6 to the fine position by the drive of the pump motor 63. When the wind turbine blade 6 is in the fine position, the drive of the pump motor 63 stops (time Ts in Figure 5), and at the same time, the connection state of the hydraulic valve 85 is switched. Hydraulic fluid is released from the hydraulic accumulator 65 and supplied to the first chamber 23A of the hydraulic cylinder 22. As a result, the wind turbine blade 6 begins to move toward the feather position.

[0032] The solid line N1 in Figure 5 shows the change in oil supply pressure over time. The oil supply pressure decreases as hydraulic fluid is supplied to the hydraulic cylinder 22. In the first accumulator operation test mode, the amount of hydraulic fluid supplied to the hydraulic cylinder 22 is large because the wind turbine blade 6 moves from the fine position to the feather position. Therefore, regardless of whether or not a malfunction occurs in the wind turbine blade 6, the oil supply pressure falls below the first specified pressure value. Also, in the first accumulator operation test mode, the trend of decrease in oil supply pressure does not change significantly between cases where a malfunction occurs in the wind turbine blade 6 and cases where a malfunction does not occur. Therefore, for the sake of simplicity, only the solid line N1 is shown in Figure 5 as the change in oil supply pressure over time.

[0033] In Figure 5, the thick solid line L1 represents the normal movement of the wind turbine blade 6, while the thick dashed lines L2 and L3 represent the abnormal movement of the wind turbine blade 6. As shown by the thick solid line L1, when the wind turbine blade 6 is operating normally, its movement will not be slow. More specifically, the pitch angle at the time when the oil supply pressure drops to the first specified pressure value is a pitch angle closer to the feather than the specified pitch angle which is the threshold. Here, the timing when the oil supply pressure reaches the first specified pressure value corresponds to time Td, and the specified pitch angle is θ dThis corresponds to the above. On the other hand, as shown by the thick dashed lines L2 and L3, if a malfunction occurs in the wind turbine blade 6, the pitch angle at time Td will be the fine pitch angle. Hereafter, the condition in which the pitch angle of the wind turbine blade 6 at the time when the oil supply pressure drops to the first specified pressure value is a fine pitch angle compared to the specified pitch angle will be called the "pitch angle abnormality condition". If the pitch angle abnormality condition is met, a malfunction has occurred in the wind turbine blade 6.

[0034] In the first accumulator operation test mode of this example, abnormalities in the pitch link mechanism 26 can also be diagnosed in addition to abnormalities in the hydraulic accumulator 65. Regardless of which abnormality occurs, the pitch angle abnormality condition will be satisfied, but the movement speed of the wind turbine blade 6 will change significantly depending on the abnormality that occurs. Therefore, in this example, it is also determined whether the time required from the stopping of the pump motor 63 until the wind turbine blade 6 reaches the feather position is within the first allowable time. Details are as follows.

[0035] If damage or rust occurs in the first or second link, or other components of the pitch link mechanism 26, the pitch link mechanism 26 will not be able to operate smoothly, and the speed of the wind turbine blades 6 will decrease significantly (see thick dashed line L2). While abnormalities in the pitch link mechanism 26 may occur together with abnormalities in the hydraulic accumulator 65, the failure of the required time to exceed the first allowable time is primarily due to abnormalities in the pitch link mechanism 26. Therefore, if the required time exceeds the first allowable time, the malfunction of the wind turbine blades 6 can be identified as being caused by an abnormality in the pitch link mechanism 26.

[0036] On the other hand, if the pitch link mechanism 26 is functioning correctly and there is a malfunction in the hydraulic accumulator 65, the required time for the wind turbine blade 6 will be within the first allowable time, as indicated by the thick dashed line L3. Therefore, if the pitch angle abnormality condition is met and the required time is within the first allowable time, the malfunction of the wind turbine blade 6 can be identified as being caused by a malfunction in the hydraulic accumulator 65.

[0037] Furthermore, even if there is an abnormality in the pitch link mechanism 26, the pitch angle abnormality condition is still met. Therefore, it is preferable to determine whether the required time is within the first allowable time before determining whether the pitch angle abnormality condition is met. If the required time is within the first allowable time, the pitch link mechanism 26 can be considered normal. In this case, if the pitch angle abnormality condition is met, the component of the wind power generation equipment 1 that is malfunctioning can be narrowed down to the hydraulic accumulator 65.

[0038] <3-2. Functional Configuration of the Anomaly Diagnosis System 40> Identifying abnormalities in the first accumulator operation test mode is achieved by the functional configuration of the abnormality diagnosis system 40 shown in Figure 6. The functional configuration of the abnormality diagnosis system 40 shown in Figure 6 is achieved by the hardware configuration of the abnormality diagnosis system 40 exemplified in Figure 2 (the functional configuration of the abnormality diagnosis system 40 shown in Figure 8 is similar). The abnormality diagnosis system 40 in this example includes a first acquisition unit 41, a required time determination unit 44, a pitch link mechanism abnormality diagnosis unit 45, a pitch angle determination unit 42, and a first accumulator abnormality diagnosis unit 43.

[0039] The first acquisition unit 41 is configured to acquire first data that includes at least the detection result (output signal) of the hydraulic detection unit 17 and the measurement result (output signal) of the pitch angle sensor 15. The first data includes first hydraulic time series data, first pitch angle time series data, and first pump motor control time series data. The first data may be generated by the first acquisition unit 41, or it may be generated by the control device 20 and then transmitted to the first acquisition unit 41.

[0040] The first hydraulic time series data is the time series data of the signals output by the hydraulic detection unit 17 while the wind power generation equipment 1 is operating in the first accumulator operation test mode. If a hydraulic switch is used as the hydraulic detection unit 17, the first hydraulic time series data associates the ON and OFF signals, which are the output signals of the hydraulic switch, with time. The first pitch angle time series data is the time series data of the pitch angle indicated by the signal output from the pitch angle sensor 15 while the wind power generation equipment 1 is operating in the first accumulator operation test mode. The first pitch angle time series data is shown, for example, by the thick solid line L1 and the thick dashed lines L2, L2 in Figure 5. The first pump motor control time series data associates the control commands input from the control device 20 to the pump motor 63 with time.

[0041] The required time determination unit 44 is configured to determine, in the first accumulator operation test mode, whether the time required from the time the pump motor 63 stops to the time the wind turbine blade 6 reaches the feather position is within a first allowable time. An example of the determination process is as follows: Based on the first pump motor control time series data acquired by the first acquisition unit 41, the stop time of the pump motor 63 is determined. Furthermore, the required time determination unit 44 determines the time when the wind turbine blade 6 reaches the feather position based on the first pitch angle time series data. If the determined time is the same as or earlier than the time when the first allowable time has elapsed from the stop time of the pump motor 63, it can be determined that the required time is within the first allowable time.

[0042] The pitch link mechanism abnormality diagnosis unit 45 is configured to diagnose an abnormality in the pitch link mechanism 26 when the required time determination unit 44 determines that the required time exceeds the first allowable time. Specifically, the pitch link mechanism abnormality diagnosis unit 45 generates a display command to display information indicating that there is an abnormality in the pitch link mechanism 26 on the display unit 83. The information displayed on the display unit 83 may be a text message expressed in characters, an error code expressed in alphanumeric characters, or a mark expressed in a graphic or the like.

[0043] The pitch angle determination unit 42 is configured to determine whether the above-mentioned abnormal pitch angle conditions are met based on the acquisition results of the first acquisition unit 41. When a pressure sensor is used as the hydraulic detection unit 17, a specific example of the determination process is as follows: The time when the output signal of the hydraulic switch switched is identified based on the first hydraulic time series data. Then, the pitch angle at that time is identified based on the first pitch angle time series data. By comparing the identified pitch angle with the specified pitch angle, it is determined whether the abnormal pitch angle conditions are met. In this example, the pitch angle determination unit 42 is configured to determine whether the abnormal pitch angle conditions are met only when the required time determination unit 44 determines that the required time is within the first allowable time.

[0044] The first accumulator abnormality diagnosis unit 43 is configured to diagnose an abnormality in the hydraulic accumulator 65 when the pitch angle determination unit 42 determines that the pitch angle abnormality condition is met. Specifically, the first accumulator abnormality diagnosis unit 43 generates a display command to display information on the display unit 83 indicating that there is an abnormality in the hydraulic accumulator 65, such as a drop in gas pressure in the bladder 67. The information displayed on the display unit 83 may be a text message expressed in characters, an error code expressed in alphanumeric characters, or a mark expressed in a graphic or the like. If the user of the abnormality diagnosis system 40, after confirming the information displayed on the display unit 83, arranges for repair work on the wind power generation equipment 1, such as refilling the gas pressure in the bladder 67, the abnormality in the hydraulic accumulator 65 can be resolved.

[0045] In the first accumulator operation test mode, the wind turbine blade 6 moves from the fine position to the feather position, resulting in a large amount of hydraulic fluid being released from the hydraulic accumulator 65. Therefore, if there is even a minor abnormality in the process of the hydraulic accumulator 65 releasing hydraulic fluid, malfunctions such as a decrease in movement speed will occur during the movement of the wind turbine blade 6 from the fine position to the feather position. As a result, the pitch angle abnormality condition is determined to be met, and the first accumulator abnormality diagnosis unit 43 diagnoses that there is an abnormality in the hydraulic accumulator 65. Thus, an abnormality diagnosis system 40 for wind power generation equipment that can detect abnormalities in the hydraulic accumulator 65 at an early stage is realized. To give a specific example, even if the pressure of the gas sealed in the bladder 67 of the hydraulic accumulator 65 has just decreased, the pitch angle abnormality condition will be met. Therefore, the first accumulator abnormality diagnosis unit 43 can diagnose a minor abnormality in the pressure accumulation function of the hydraulic accumulator 65. In this case, if the user of the abnormality diagnosis system 40 arranges for inspection or repair work on the wind power generation equipment 1 and the bladder 67 is filled with gas, the abnormality in the hydraulic accumulator 65 will be resolved.

[0046] Furthermore, as described above, the pitch angle determination unit 42 according to one embodiment is configured to determine whether the pitch angle abnormality condition is met when it is determined that the required time is within the first allowable time. With the above configuration, the determination of whether the pitch angle abnormality condition is met is performed on the premise that there is no abnormality in the pitch link mechanism 26. Therefore, if it is determined that the pitch angle abnormality condition is met, the component in which the abnormality is occurring can be appropriately identified as the hydraulic accumulator 65. Also, if it is determined that the required time from when the pump motor 63 stops until the wind turbine blade 6 reaches the feather position exceeds the first allowable time, the pitch link mechanism abnormality diagnosis unit 45 can diagnose that there is an abnormality in the pitch link mechanism 26.

[0047] Furthermore, as described above, the pitch angle determination unit 42 according to one embodiment is configured to determine whether the pitch angle abnormality condition is met based on the acquisition result of the first acquisition unit 41. With the above configuration, data indicating the oil supply pressure and pitch angle in the first accumulator operation test mode can be acquired, so the pitch angle determination unit 42 can accurately determine whether the pitch angle abnormality condition is met.

[0048] Furthermore, as described above, the hydraulic detection unit 17 according to one embodiment is a pressure switch configured to switch the output signal when the oil supply pressure falls below a first specified pressure value. With this configuration, the process by which the first acquisition unit 41 acquires the output signal of the hydraulic detection unit 17 can be simplified compared to the case where a hydraulic sensor that continuously measures the oil supply pressure is used as the hydraulic detection unit 17. In addition, the configuration of the wind power generation equipment 1 can also be simplified.

[0049] Furthermore, even if a more serious abnormality occurs in the hydraulic accumulator 65 than the decrease in gas pressure of the bladder 67, the pitch angle abnormality condition is still met. For example, if the bladder 67 is damaged, even if the first accumulator abnormality diagnosis unit 43 diagnoses an abnormality in the hydraulic accumulator 65 and then refills the bladder 67 with gas pressure, the pitch angle abnormality condition will not be met in the subsequent first accumulator operation test mode. Therefore, the abnormality diagnosis system 40 illustrated in Figure 6 may further include an accumulator severe abnormality diagnosis unit 46.

[0050] The accumulator severe abnormality diagnosis unit 46 is configured to diagnose a more serious abnormality in the hydraulic accumulator 65 than the abnormality diagnosed by the first accumulator abnormality diagnosis unit 43 if the first accumulator abnormality diagnosis unit 43 diagnoses an abnormality two or more times within a predetermined period.

[0051] More specifically, after the first accumulator anomaly diagnosis unit 43 diagnoses an anomaly, repair work is performed on the wind power generation equipment 1. The date and time the repair work is performed is stored in the HDD 78 of the anomaly diagnosis system 40. After the anomaly is deemed to have been resolved by the repair work, if the first accumulator anomaly diagnosis unit 43 diagnoses an anomaly again, it is determined whether the period between the repair work and the re-diagnosis of an anomaly falls below a predetermined period. The predetermined period is a few days, a few weeks, or a few months. If it is determined that the first accumulator anomaly diagnosis unit 43 has diagnosed an anomaly two or more times within the predetermined period, the accumulator severe anomaly diagnosis unit 46 diagnoses that there is a serious anomaly in the hydraulic accumulator 65. In this case, the first accumulator anomaly diagnosis unit 43 may generate a display command to display information on the display unit 83 indicating that there is a serious anomaly in the hydraulic accumulator 65. This allows the user of the anomaly diagnosis system 40 to arrange for work such as replacing the bladder 67.

[0052] With the above configuration, the accumulator severe malfunction diagnosis unit 46 can diagnose a serious malfunction in the hydraulic accumulator 65. Therefore, countermeasures such as replacing the bladder 67 can be taken before a failure that is difficult to repair occurs in the wind power generation equipment 1.

[0053] <3-3. Supplementary Information> Furthermore, the abnormality diagnosis system 40 does not necessarily have a configuration to determine whether there is an abnormality in the pitch link mechanism 26. For example, if the durability of the pitch link mechanism 26 is sufficiently guaranteed, the operation of the wind turbine blade 6 as shown by the thick dashed line L2 in Figure 5 is unlikely to occur. In this case, the abnormality diagnosis system 40 does not need to include the required time determination unit 44 and the pitch link mechanism abnormality diagnosis unit 45. If the pitch angle abnormality condition is not met, it may be diagnosed that there is an abnormality in the hydraulic accumulator 65. Also, the hydraulic pressure detection unit 17 may be a pressure sensor configured to measure the hydraulic pressure in the main line 103. Since the pressure sensor can continuously measure the hydraulic pressure, the signal output from the pressure sensor will differ depending on whether the hydraulic pressure is below the first specified pressure value. In this case, the first hydraulic pressure time series data mentioned above will show the time series data of the measured oil supply pressure. It is also possible to determine whether the pitch angle abnormality condition is met using such time series data.

[0054] <4. Second Accumulator Operation Test Mode> Referring to Figures 7 and 8, the second accumulator operation test mode and the functional configuration of the abnormality diagnosis system 40 for performing abnormality diagnosis in the second accumulator operation test mode will be explained. In Figure 8, the first acquisition unit 41, the pitch angle determination unit 42, and the first accumulator abnormality diagnosis unit 43 described above are collectively referred to as the "first abnormality diagnosis component 31" (see Figure 8).

[0055] <4-1. Details of the operational test> Figure 7 is a schematic graph showing time-series data of pitch angle and oil supply pressure in the second accumulator operation test mode. The horizontal axis of the graph represents time. The vertical axis on the left represents the pitch angle, θ. fe θ is the pitch angle corresponding to the feather position. mThe symbol indicates an intermediate position. An intermediate position is a position on the movement path of the wind turbine blade 6, and is located between the feather position and the fine position. In this example, the distance traveled by the wind turbine blade 6 from the feather position to the intermediate position is less than half, more precisely less than one-third, and even more precisely less than one-quarter, of the distance traveled by the wind turbine blade 6 from the feather position to the fine position. The vertical axis on the right side of the graph represents the oil supply pressure.

[0056] In the second accumulator operation test mode, the pump motor 63 and the hydraulic accumulator 65 operate so that the wind turbine blade 6 moves back and forth between the feather position and the intermediate position. Specifically, the hydraulic accumulator 65 moves the wind turbine blade 6 to the feather position when driven by the pump motor 63. When the wind turbine blade 6 is in the feather position, the pump motor 63 stops operating (time Tx in Figure 7), and at the same time, the connection state of the hydraulic valve 85 switches. Hydraulic fluid is released from the hydraulic accumulator 65 and supplied to the second chamber 23B of the hydraulic cylinder 22. The wind turbine blade 6 begins to move toward the intermediate position. When the wind turbine blade 6 reaches the intermediate position, the connection state of the hydraulic valve 85 switches again, hydraulic fluid is supplied to the first chamber 23A, and the wind turbine blade 6 returns to the feather position.

[0057] When the hydraulic accumulator 65 operates normally, the movement speed of the wind turbine blades 6 reaches an appropriate level. Therefore, as shown by the thick solid line K1, the round-trip movement time of the wind turbine blades 6 is within the second allowable time. On the other hand, if there is a serious malfunction in the hydraulic valve 85, the movement speed of the wind turbine blades 6 falls below the appropriate level due to the delay in the operation of the wind turbine blades 6. Therefore, as shown by the thick dashed line K2, the round-trip movement time of the wind turbine blades 6 exceeds the second allowable time. Note that the second allowable time is longer than the first allowable time mentioned above.

[0058] Furthermore, if an abnormality occurs in the hydraulic accumulator 65 during the second accumulator operation test mode, the trend of the decrease in oil supply pressure also changes significantly. As shown by the solid line J1 in Figure 7, when the hydraulic accumulator 65 is operating normally, the oil supply pressure will never fall below the second specified pressure value, which serves as a threshold. The second specified pressure value may, for example, be 75% or less of the rated pressure of the hydraulic accumulator 65, or 50% or less. The second specified pressure value may, for example, be the same as the first specified pressure value. On the other hand, as shown by the dashed line J2, if there is an abnormality in the operation of the hydraulic accumulator 65, the oil supply pressure will fall below the second specified pressure value during the initial operation of the wind turbine blade 6. The initial operation is the movement of the wind turbine blade 6 from the feather position by a distance of less than one-quarter of the distance traveled from the feather position to the fine position. In addition, according to the inventors' findings, if a pressure drop occurs in the hydraulic accumulator 65, the oil supply pressure will decrease during the medium-term operation of the wind turbine blade 6. The intermediate motion is the movement of the wind turbine blade 6 after the initial motion. The intermediate motion may also be movement toward the fine position after the initial motion.

[0059] The identification of abnormalities in the second accumulator operation test mode described above is achieved by the following functional configuration of the abnormality diagnosis system 40.

[0060] <4-2. Functional Configuration of the Anomaly Diagnosis System 40> Figure 8 is a schematic block diagram showing the functional configuration of an abnormality diagnosis system 40 according to one embodiment. In addition to the first abnormality diagnosis component 31, the abnormality diagnosis system 40 in this example includes a second acquisition unit 47, a round-trip travel time determination unit 48, a hydraulic valve abnormality diagnosis unit 49, a hydraulic pressure drop determination unit 51, and a second accumulator abnormality diagnosis unit 53.

[0061] The second acquisition unit 47 is configured to acquire second data that includes at least the detection result (output signal) of the hydraulic detection unit 17 and the measurement result (output signal) of the pitch angle sensor 15. In this example, the second data includes second hydraulic time series data, second pitch angle time series data, and second pump motor control time series data. The second data may be generated by the second acquisition unit 47, or it may be generated by the control device 20 and then transmitted to the second acquisition unit 47.

[0062] The second hydraulic time series data is the time series data of the signals output by the hydraulic detection unit 17 while the wind power generation equipment 1 is operating in the second accumulator operation test mode. If a hydraulic switch is used as the hydraulic detection unit 17, the second hydraulic time series data associates the ON and OFF signals, which are the output signals of the hydraulic switch, with time. The second pitch angle time series data is the time series data of the pitch angle indicated by the signal output from the pitch angle sensor 15 while the wind power generation equipment 1 is operating in the second accumulator operation test mode. The second pitch angle time series data is shown, for example, by the thick solid line K1 and the thick dashed line K2 in Figure 7. The second pump motor control time series data associates the control commands input from the control device 20 to the pump motor 63 with time.

[0063] The round-trip travel time determination unit 48 is configured to determine whether the round-trip travel time of the wind turbine blade 6 is within the second allowable time in the second accumulator operation test mode. This determination is made based on the second data. An example of the specific determination process is as follows: Based on the second pump motor control time series data, the stop time of the pump motor 63 is determined. At the same time, the time when the wind turbine blade 6 returns to the feather position is determined based on the second pitch angle time series data mentioned above. This determines the round-trip travel time of the wind turbine blade 6, and it is determined whether the round-trip travel time of the wind turbine blade 6 is within the second allowable time.

[0064] The hydraulic valve malfunction diagnosis unit 49 is configured to determine that there is a malfunction in the hydraulic accumulator 65 if the round-trip travel time determination unit 48 determines that the round-trip travel time exceeds the second allowable time. Specifically, the hydraulic valve malfunction diagnosis unit 49 generates a display command to display information indicating that there is a malfunction in the hydraulic accumulator 65 on the display unit 83.

[0065] According to the above configuration, in the second accumulator operation test mode, the wind turbine blade 6 reciprocates between the feather position and the intermediate position, so the amount of hydraulic fluid discharged from the hydraulic accumulator 65 is suppressed. Nevertheless, if the reciprocating movement time of the wind turbine blade 6 exceeds the second allowable time, it can be determined that a serious abnormality has occurred in the hydraulic accumulator 65. In such cases, the hydraulic valve abnormality diagnosis unit 49 diagnoses the abnormality in the hydraulic accumulator 65, thus avoiding a failure to detect the abnormality in the hydraulic accumulator 65.

[0066] The hydraulic pressure drop determination unit 51 is configured to determine whether the oil supply pressure falls below the second specified pressure value during the initial operation of the wind turbine blades 6 after the pump motor 63 has stopped, in the second accumulator operation test mode. This determination is performed based on the second hydraulic pressure time series data. This allows for the determination of whether the oil supply pressure is below the second specified pressure value.

[0067] The second accumulator abnormality diagnosis unit 53 is configured to determine that there is an abnormality in the hydraulic accumulator 65 when the hydraulic pressure drop determination unit 51 determines that the oil supply pressure during initial operation has fallen below the second specified pressure value. Specifically, the second accumulator abnormality diagnosis unit 53 generates a display command to display information indicating that there is an abnormality in the hydraulic accumulator 65 on the display unit 83.

[0068] Furthermore, the round-trip travel time determination unit 48 may be configured to determine whether the round-trip travel time is within the second allowable time when the hydraulic pressure drop determination unit 51 determines that the oil supply pressure exceeds the second specified pressure value. In the second accumulator operation test mode, if the bladder 67 is damaged, the oil supply pressure tends to fall below the second specified pressure value. However, due to the influence of the hydraulic pressure of the hydraulic fluid remaining in the main line 103 of the hydraulic fluid supply line 62, the hydraulic pressure may not fall below the second specified pressure value even if the bladder 67 is damaged. This could lead to a failure to detect an abnormality in the hydraulic accumulator 65. In this regard, with the above configuration, even if the hydraulic pressure is determined to be above the second specified pressure value, the round-trip travel time determination unit 48 determines whether the round-trip travel time is within the second allowable time. And, if the bladder 67 is damaged, the wind turbine blade 6 will take time to move back and forth, so the round-trip travel time will exceed the second allowable time. In this case, the hydraulic valve abnormality diagnosis unit 49 can diagnose that there is an abnormality in the hydraulic valve 85, thus avoiding the failure to detect an abnormality in the hydraulic valve 85.

[0069] <4-3. Others> The pitch angle determination unit 42 of the first abnormality diagnosis component 31 described above may determine whether the pitch angle abnormality condition is met when the reciprocating movement time determination unit 48 determines that the reciprocating movement time of the wind turbine blade 6 falls within the second allowable time. In other words, the abnormality diagnosis based on the first accumulator operation test mode may be performed when the abnormality diagnosis based on the second accumulator operation test mode determines that the wind power generation equipment 1 is normal. With this configuration, it is determined whether the pitch angle abnormality condition is met when no serious abnormality has occurred in the hydraulic accumulator 65. Therefore, if the pitch angle abnormality condition is met, the abnormality in the hydraulic accumulator 65 can be identified as a minor abnormality that is generally difficult to detect early, rather than a severe abnormality. This allows for early detection of abnormalities in the hydraulic accumulator 65.

[0070] The hydraulic pressure detection unit 17 may be a pressure sensor instead of a hydraulic pressure switch. In this case, the second specified pressure value may be a different oil supply pressure from the first specified pressure value. Furthermore, the abnormality diagnosis system 40 shown in Figure 8 may further include a required time determination unit 44 and a pitch link mechanism abnormality diagnosis unit 45, or an accumulator severe abnormality diagnosis unit 46.

[0071] <5. Accumulator Operation Test Procedure for Wind Power Generation Equipment 1> Referring to Figure 9, the accumulator operation test process for switching the operating mode of the wind power generation equipment 1 to either the first accumulator operation test mode or the second accumulator operation test mode will be described. The accumulator operation test process is repeatedly performed by the controller that constitutes the control device 20. Before the accumulator operation test process is started, the wind power generation equipment 1 is operating in a normal operating mode to bring the power generation amount to the target power generation amount.

[0072] The first accumulator operation test mode is executed each time the first specified period has elapsed, and the second accumulator operation test mode is executed each time the second specified period has elapsed. In this example, the operation of the second accumulator operation test mode is performed more frequently than the operation of the first accumulator operation test mode. That is, the second specified period is shorter than the first specified period. For example, the first specified period is several weeks or several months, and the second specified period is several days or several weeks. Also, the predetermined period mentioned above, which is used as a criterion for determining whether a severe abnormality has occurred in the hydraulic accumulator 65, is longer than the first specified period. In this example, the predetermined period is, for example, several months. Hereinafter, the controller that constitutes the control device 20 may be simply referred to as "controller".

[0073] First, the controller determines whether a first specified period has elapsed since the last operation of the first accumulator operation test mode (S11). If it is determined that the first specified period has not elapsed (S11: NO), the controller determines whether a second specified period has elapsed since the last operation of the second accumulator operation test mode (S13). If it is determined that the second specified period has not elapsed (S13: NO), the controller terminates the accumulator operation test process.

[0074] If it is determined that the second specified period has elapsed (S13: YES), the controller starts operation in the second accumulator operation test mode (S15). Operation in the second accumulator operation test mode starts when predetermined control commands are input to the pump motor 63 and the hydraulic valve 85.

[0075] The controller transmits data indicating the detection result (output signal) of the hydraulic detection unit 17 and the measurement result (output signal) of the pitch angle sensor 15 to the anomaly diagnosis system 40 (S17). The data may be transmitted each time the hydraulic detection unit 17 or the pitch angle sensor 15 outputs a signal. Alternatively, time-series data may be generated by associating the signals output from the hydraulic detection unit 17 and the pitch angle sensor 15 with time during operation in the second accumulator operation test mode, and the controller may transmit the time-series data to the anomaly diagnosis system 40. The data transmitted to the anomaly diagnosis system 40 in S17 is used for anomaly diagnosis in the second accumulator operation test mode (details will be described later).

[0076] Subsequently, the controller terminates the operation of the second accumulator operation test mode (S19) and ends the accumulator operation test process. The timing of the end of operation is when the wind turbine blade 6 returns to the feather position. The controller determines whether the wind turbine blade 6 has returned to the feather position based on the measurement result of the pitch angle sensor 15.

[0077] If it is determined that the first specified period has elapsed (S11: YES), the controller starts operation in the first accumulator operation test mode (S21). Operation in the first accumulator operation test mode is started when predetermined control commands are input to the pump motor 63 and the hydraulic valve 85.

[0078] The controller transmits data indicating the detection result (output signal) of the hydraulic detection unit 17 and the measurement result (output signal) of the pitch angle sensor 15 to the abnormality diagnosis system 40 (S23). S23 is the same process as S17. The data transmitted to the abnormality diagnosis system 40 in S23 is used for abnormality diagnosis in the first accumulator operation test mode (details will be described later).

[0079] Subsequently, the controller terminates the operation of the first accumulator operation test mode (S25) and ends the accumulator operation test process. The timing of the end of operation is the same as in S19, when the wind turbine blade 6 returns to the feather position.

[0080] <6. High-frequency anomaly diagnosis processing> Referring to Figure 10, the high-frequency abnormality diagnosis process, which is an abnormality diagnosis in the second accumulator operation test mode, will be explained. The high-frequency abnormality diagnosis process is executed each time the wind power generation equipment 1 is operated in the second accumulator operation test mode.

[0081] First, the processor 72 acquires second data (S30) by receiving data transmitted in S17 of the accumulator operation test process (see Figure 9). The data received in S17 may be the second data, or the processor 72 may generate the second data based on the received data. The processor 72 executing S30 is an example of a second acquisition unit 47.

[0082] The processor 72 determines, based on the second data, whether the oil supply pressure during the initial operation of the wind turbine blade 6 in the second accumulator operation test mode is below the second specified pressure value (S31). The processor 72 that performs S31 is an example of the hydraulic pressure drop determination unit 51.

[0083] If it is determined that the oil supply pressure is below the second specified pressure value (S31: YES), the processor 72 diagnoses that there is a serious abnormality in the hydraulic accumulator 65, such as a drop in the gas pressure of the bladder 67 or damage to the bladder 67 (S32). The processor 72 executing S32 is an example of the second accumulator abnormality diagnosis unit 53. After executing S32, the processor 72 terminates the high-frequency abnormality diagnosis process.

[0084] If it is determined that the oil supply pressure exceeds the second specified pressure value (S31: NO), the processor 72 determines, based on the second data, whether the oil supply pressure decreased during the medium-term operation of the wind turbine blade 6 in the second accumulator operation test mode (S33). If it is determined that it has decreased (S33: YES), the processor 72 diagnoses a minor abnormality, such as a decrease in the gas pressure of the hydraulic accumulator 65 (S34), and terminates the process. If it is determined that there has been no decrease in gas pressure during the medium-term operation (S33: NO), the processor 72 determines, based on the second data, whether the round-trip travel time of the wind turbine blade 6 is within the second allowable time (S37). The processor 72 executing S37 is an example of the round-trip travel time determination unit 48. If the round-trip travel time determination unit 48 determines that it is within the second allowable time (S37: YES), the hydraulic accumulator 65 is considered normal, and the processor 72 terminates the high-frequency abnormality diagnosis process.

[0085] If it is determined that the round-trip travel time exceeds the second allowable time (S37: NO), the processor 72 diagnoses that there is an abnormality in the hydraulic valve 85 (S39). The processor 72 executing S39 is an example of the hydraulic valve abnormality diagnosis unit 49. After executing S39, the processor 72 terminates the high-frequency abnormality diagnosis process.

[0086] <7. Low-frequency anomaly diagnosis processing> Referring to Figure 11, the low-frequency anomaly diagnosis process, which is an anomaly diagnosis in the first accumulator operation test mode, will be explained. The low-frequency anomaly diagnosis process is performed each time the wind power generation equipment 1 is operated in the first accumulator operation test mode.

[0087] First, the processor 72 acquires first data (S51) by receiving data transmitted in S23 of the accumulator operation test process (see Figure 9). The data received in S23 may be the first data, or the processor 72 may generate the first data based on the received data. The processor 72 executing S51 is an example of the first acquisition unit 41.

[0088] Next, the processor 72 determines, based on the first data, whether the required time described above is within the first allowable time (S53). The processor 72 executing S53 is an example of the required time determination unit 44. If it is determined that the required time exceeds the first allowable time (S53: NO), the processor 72 diagnoses that there is an abnormality in the pitch link mechanism 26 (S55). For example, the processor 72 sends a predetermined display command to the display unit 83. The processor 72 executing S55 is an example of the pitch link mechanism abnormality diagnosis unit 45. The processor 72 that has executed S55 terminates the low-frequency abnormality diagnosis process.

[0089] If it is determined that the required time is within the first allowable time (S53:YES), the processor 72 determines whether the pitch angle abnormality condition is met based on the first data (S57). The processor 72 executing S57 is an example of the pitch angle determination unit 42. If it is determined that the pitch angle abnormality condition is not met (S57:NO), both the pitch link mechanism 26 and the hydraulic accumulator 65 are considered normal, and the processor 72 terminates the low-frequency abnormality diagnosis process.

[0090] If it is determined that the pitch angle abnormality condition is met (S57:YES), the processor 72 determines whether a predetermined period has elapsed since the last time it was determined that the pitch angle abnormality condition was not met (S59). If it is determined that the predetermined period has elapsed (S59:YES), the processor 72 diagnoses that there is an abnormality in the hydraulic accumulator 65, such as a decrease in the gas pressure of the bladder 67 (S61). If it is determined that the predetermined period has not elapsed (S59:NO), the processor 72 diagnoses that there is a severe abnormality in the hydraulic accumulator 65, such as damage to the bladder 67 (S63). The processor 72 executing S61 is an example of the first accumulator abnormality diagnosis unit 43, and the processor 72 executing S63 is an example of the accumulator severe abnormality diagnosis unit 46. The processor 72 that has executed S61 or S63 terminates the low-frequency abnormality diagnosis process.

[0091] <8. Summary> The contents described in some of the embodiments above can be understood, for example, as follows:

[0092] 1) An anomaly diagnosis system (40) for wind power generation equipment according to at least one embodiment of the present disclosure is: An abnormality diagnosis system for a wind power generation facility (1) equipped with a hydraulic blade pitch mechanism (12), In the first accumulator operation test mode of the wind power generation equipment, in which the pump motor (63) is stopped when the wind turbine blade (6) is positioned in the fine position and the wind turbine blade moves toward the feather position by the hydraulic fluid released from the hydraulic accumulator (65), a pitch angle determination unit (42) is provided to determine whether the pitch angle abnormality condition is met, in which the pitch angle of the wind turbine blade at the timing when the hydraulic pressure of the hydraulic accumulator drops to a first specified pressure value is a pitch angle that is finer than the specified pitch angle, If it is determined that the above pitch angle abnormality condition is met, a first accumulator abnormality diagnosis unit (43) for diagnosing that there is an abnormality in the hydraulic accumulator, It is equipped with.

[0093] In the first accumulator operation test mode, the wind turbine blades move from the fine position to the feather position, resulting in a large amount of hydraulic fluid being released from the hydraulic accumulator. Therefore, even a minor abnormality in the process of the hydraulic accumulator releasing hydraulic fluid will cause malfunctions such as a decrease in the movement speed of the wind turbine blades during the movement from the fine position to the feather position. As a result, the pitch angle abnormality condition is determined to be met, and the first accumulator abnormality diagnosis unit diagnoses an abnormality in the hydraulic accumulator. Thus, an abnormality diagnosis system for wind power generation equipment that can detect abnormalities in the hydraulic accumulator at an early stage is realized. To give a specific example, even if the pressure of the gas sealed in the bladder of the hydraulic accumulator has just dropped, the pitch angle abnormality condition will be met. Therefore, the first accumulator abnormality diagnosis unit can diagnose a minor abnormality in the pressure accumulation function of the hydraulic accumulator.

[0094] 2) In some embodiments, the abnormality diagnosis system for wind power generation equipment described in 1) above, In the first accumulator operation test mode, a time determination unit (44) for determining whether the time required from the time the pump motor stops until the wind turbine blade reaches the feather position is within a first allowable time, If it is determined that the required time exceeds the first allowable time, a pitch link mechanism abnormality diagnosis unit (45) is provided to diagnose that there is an abnormality in the pitch link mechanism (26) connected to the piston (24) of the hydraulic cylinder (22) and the wind turbine blade. Furthermore, The pitch angle determination unit is configured to determine whether the pitch angle abnormality condition is satisfied when it is determined that the required time is within the first allowable time.

[0095] If there is a problem with the pitch linkage mechanism, the wind turbine blades cannot move to the feather position properly in the first accumulator operation test mode, even if the hydraulic accumulator is functioning correctly. In this regard, according to the configuration of 2) above, if it is determined that the time required from the stopping of the pump motor until the wind turbine blades reach the feather position exceeds the first allowable time, the pitch linkage mechanism abnormality diagnosis unit can diagnose that there is a problem with the pitch linkage mechanism. Furthermore, the determination of whether the pitch angle abnormality condition is met is performed on the premise that there is no problem with the pitch linkage mechanism. Therefore, if it is determined that the pitch angle abnormality condition is met, the component in which the abnormality is occurring can be appropriately identified as the hydraulic accumulator.

[0096] 3) In some embodiments, an abnormality diagnosis system for wind power generation equipment as described in 1) or 2) above, If the first accumulator abnormality diagnosis unit diagnoses an abnormality two or more times within a predetermined period, the system further includes an accumulator severe abnormality diagnosis unit (46) for diagnosing that there is a more serious abnormality in the hydraulic accumulator than the abnormality diagnosed by the first accumulator abnormality diagnosis unit.

[0097] After the first accumulator abnormality diagnosis unit diagnoses a minor abnormality in the hydraulic accumulator, the abnormality is resolved through inspection or repair work. However, if the first accumulator abnormality diagnosis unit diagnoses an abnormality again within a predetermined period, it is assumed that a serious abnormality, such as bladder damage in the hydraulic accumulator, has occurred. In this regard, according to the configuration of 3) above, in such a case, the accumulator severe abnormality diagnosis unit can diagnose a serious abnormality in the hydraulic accumulator. Therefore, countermeasures such as bladder replacement can be taken before a failure that is difficult to recover occurs in the wind power generation equipment.

[0098] 4) In some embodiments, an abnormality diagnosis system for wind power generation equipment according to any one of 1) to 3) above, The system further includes a first acquisition unit (41) for acquiring data showing the detection result of a hydraulic pressure detection unit (17) configured to output different signals depending on whether the hydraulic pressure of the hydraulic accumulator is below a first specified pressure value, and the measurement result of the pitch angle sensor (15) of the wind power generation equipment. The pitch angle determination unit is configured to determine whether the pitch angle abnormality condition is met based on the acquisition result of the first acquisition unit.

[0099] According to the configuration described in 4) above, data indicating the hydraulic pressure and pitch angle in the operation test mode of the first accumulator can be obtained, so the pitch angle determination unit can accurately determine whether the pitch angle abnormality condition is met.

[0100] 5) In some embodiments, the abnormality diagnosis system for wind power generation equipment described in 4) above, The hydraulic pressure detection unit is a pressure switch configured to switch an output signal when the hydraulic pressure falls below a first specified pressure value.

[0101] According to the configuration described in 5) above, the process by which the first acquisition unit acquires the output signal from the hydraulic detection unit can be simplified compared to the case where a hydraulic sensor that continuously measures hydraulic pressure is used as the hydraulic detection unit. Furthermore, the configuration of the wind power generation equipment can also be simplified.

[0102] 6) In some embodiments, an abnormality diagnosis system for wind power generation equipment according to any one of 1) to 5) above, In the second accumulator operation test mode of the wind power generation equipment, in which the drive of the pump motor is stopped when the wind turbine blade is positioned in the feather position, and the wind turbine blade moves from the feather position to an intermediate position and then returns to the feather position by the hydraulic fluid released from the hydraulic accumulator, a reciprocating movement time determination unit (48) for determining whether the reciprocating movement time of the wind turbine blade is within the second allowable time, A hydraulic valve abnormality diagnosis unit (49) for diagnosing an abnormality in a hydraulic valve when it is determined that the reciprocating travel time exceeds the second allowable time, wherein the hydraulic valve is a valve configured to switch the supply destination of the hydraulic fluid between a first chamber (23A) and a second chamber (23B) separated by a piston (24) in the hydraulic cylinder (22) of the hydraulic blade pitch mechanism, To further prepare.

[0103] According to the configuration in 6) above, it is possible to avoid failing to detect abnormalities in the hydraulic valve.

[0104] 7) In some embodiments, the abnormality diagnosis system for wind power generation equipment described in 6) above, The pitch angle determination unit is configured to determine whether the pitch angle abnormality condition is met when it is determined that the reciprocating movement time of the wind turbine blade falls within the second allowable time.

[0105] According to the configuration described in 7) above, if no serious abnormality occurs in the hydraulic accumulator, it is determined whether the pitch angle abnormality condition is met. Therefore, if the pitch angle abnormality condition is met, the abnormality in the hydraulic accumulator can be identified as minor. This realizes an abnormality diagnosis system for wind power generation equipment that can detect abnormalities in the hydraulic accumulator at an early stage.

[0106] 8) An abnormality diagnosis method for wind power generation equipment according to at least one embodiment of the present disclosure is: A method for diagnosing abnormalities in a wind power generation facility (1) equipped with a hydraulic blade pitch mechanism (12), In the first accumulator operation test mode of the wind power generation equipment, in which the drive of the pump motor (63) is stopped when the wind turbine blade (6) is positioned in the fine position, and the wind turbine blade moves toward the feather position by the hydraulic fluid released from the hydraulic accumulator (65), a pitch angle determination step (S57) is performed to determine whether the pitch angle abnormality condition is satisfied, in which the pitch angle of the wind turbine blade at the timing when the hydraulic pressure of the hydraulic accumulator drops to a first specified pressure value is a pitch angle that is finer than the specified pitch angle, If it is determined that the above-mentioned pitch angle abnormality condition is met, a first accumulator abnormality diagnosis step (S61) is performed to diagnose that there is an abnormality in the hydraulic accumulator, It is equipped with.

[0107] According to the configuration described in 8) above, a fault diagnosis method for wind power generation equipment that can detect abnormalities in the hydraulic accumulator at an early stage is realized for the same reasons as described in 1) above. [Explanation of Symbols]

[0108] 1: Wind power generation equipment 6: Windmill blade 12: Hydraulic blade pitch mechanism 15: Pitch Angle Sensor 17: Hydraulic detection unit 22: Hydraulic Cylinder 23: liters 24: Piston 26: Pitch linkage mechanism 40: Anomaly Diagnosis System 41:First acquisition part 42: Pitch angle determination unit 43: First Accumulator Abnormality Diagnosis Department 44: Time Determination Unit 45: Pitch linkage mechanism anomaly diagnosis unit 46: Accumulator Severe Abnormality Diagnosis Department 48: Round-trip travel time determination unit 49: Hydraulic Valve Anomaly Diagnosis Unit 51: Hydraulic pressure drop detection unit 63: Pump motor 65: Hydraulic accumulator

Claims

1. An anomaly diagnosis system for wind power generation equipment equipped with a hydraulic blade pitch mechanism, In a first accumulator operation test mode of the wind power generation equipment, in which the pump motor is stopped while the wind turbine blades are positioned in the fine position and the wind turbine blades are moved toward the feather position by the hydraulic fluid released from the hydraulic accumulator, a pitch angle determination unit is provided to determine whether a pitch angle abnormality condition is met, in which the pitch angle of the wind turbine blades at the timing when the hydraulic pressure of the hydraulic accumulator drops to a first specified pressure value is a pitch angle that is finer than the specified pitch angle, If it is determined that the above pitch angle abnormality condition is met, a first accumulator abnormality diagnosis unit for diagnosing that there is an abnormality in the hydraulic accumulator, Equipped with, An anomaly detection system for wind power generation equipment.

2. In the first accumulator operation test mode, a time determination unit for determining whether the time required from the time the pump motor stops until the wind turbine blade reaches the feather position is within a first allowable time, If it is determined that the required time exceeds the first allowable time, a pitch link mechanism abnormality diagnosis unit is provided to diagnose that there is an abnormality in the pitch link mechanism connecting the piston of the hydraulic cylinder and the wind turbine blade. Furthermore, The pitch angle determination unit is configured to determine whether the pitch angle abnormality condition is satisfied when it is determined that the required time is within the first allowable time. An anomaly diagnosis system for wind power generation equipment according to claim 1.

3. If the first accumulator abnormality diagnosis unit diagnoses an abnormality two or more times within a predetermined period, the system further comprises an accumulator severe abnormality diagnosis unit for diagnosing that there is a more serious abnormality in the hydraulic accumulator than the abnormality diagnosed by the first accumulator abnormality diagnosis unit. An abnormality diagnosis system for wind power generation equipment according to claim 1 or 2.

4. The system further includes a first acquisition unit for acquiring data showing the detection result of a hydraulic pressure detection unit, which is configured to output different signals depending on whether the hydraulic pressure of the hydraulic accumulator is below a first specified pressure value, and the measurement result of the pitch angle sensor of the wind power generation equipment. The pitch angle determination unit is configured to determine whether the pitch angle abnormality condition is met based on the acquisition result of the first acquisition unit. An abnormality diagnosis system for wind power generation equipment according to claim 1 or 2.

5. The hydraulic pressure detection unit is a pressure switch configured to switch an output signal when the hydraulic pressure falls below a first specified pressure value. An anomaly diagnosis system for wind power generation equipment according to claim 4.

6. In the second accumulator operation test mode of the wind power generation equipment, in which the pump motor is stopped when the wind turbine blade is positioned in the feather position, and the wind turbine blade moves from the feather position to an intermediate position and then returns to the feather position by the hydraulic fluid released from the hydraulic accumulator, a reciprocating movement time determination unit for determining whether the reciprocating movement time of the wind turbine blade is within a second allowable time, A hydraulic valve malfunction diagnosis unit for diagnosing a malfunction in a hydraulic valve when it is determined that the reciprocating travel time exceeds the second allowable time, wherein the hydraulic valve is a valve configured to switch the supply destination of the hydraulic fluid between a first chamber and a second chamber separated by a piston in the hydraulic cylinder of the hydraulic blade pitch mechanism, Furthermore, An abnormality diagnosis system for wind power generation equipment according to claim 1 or 2.

7. The pitch angle determination unit is configured to determine whether the pitch angle abnormality condition is met when it is determined that the reciprocating movement time of the wind turbine blade falls within the second allowable time. An abnormality diagnosis system for wind power generation equipment according to claim 6.

8. An abnormality diagnosis method for wind power generation equipment equipped with a hydraulic blade pitch mechanism, In a first accumulator operation test mode of the wind power generation equipment, in which the pump motor is stopped while the wind turbine blades are positioned in the fine position, and the wind turbine blades are moved toward the feather position by the hydraulic fluid released from the hydraulic accumulator, a pitch angle determination step is made to determine whether a pitch angle abnormality condition is met, in which the pitch angle of the wind turbine blades at the timing when the hydraulic pressure of the hydraulic accumulator drops to a first specified pressure value is a pitch angle that is finer than the specified pitch angle, If it is determined that the above-mentioned pitch angle abnormality condition is met, a first accumulator abnormality diagnosis step is performed to diagnose that there is an abnormality in the hydraulic accumulator, Equipped with, A method for diagnosing abnormalities in wind power generation equipment.

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