Windmill abnormality diagnosis device, method, and program

Abstract

To provide a windmill diagnostic technology that can be carried out without dispatching an operator.SOLUTION: A device for diagnosing a fault of a windmill includes: a transmission unit for transmitting operation information 36 of vibration excitation means 45 for exciting a structure 33 (33a, 33b...); a reception unit for receiving detection data 43 from a plurality of vibration sensors 34 installed on the structure 33 respectively; and an analysis unit for performing frequency analysis of the detection data 43.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to a technique for diagnosing abnormalities in wind turbines used for wind power generation.

Background Art

[0002] Wind power is one of the renewable energy sources that exists everywhere, does not emit carbon dioxide, and can be used permanently without depletion. To promote power generation using such wind power, it is important to establish a technique for diagnosing the soundness of operation in order to improve the stability and sustainability of power generation. Diagnosis of a wind power generation system includes SCADA (Supervisory Control And Data Acquisition) for diagnosing the operating state of a wind turbine, and CMS (Condition Monitoring System) for individually diagnosing damage and deterioration of structures, etc.

[0003] In SCADA, operating information such as wind direction, wind volume, power generation output, pitch angle, nacelle angle, main shaft rotation speed, oil temperature, bearing temperature, generator temperature, temperature inside the nacelle, outside air temperature, etc. is collected. On the other hand, in CMS, detection data such as vibration and sound by sensors installed in structures is collected.

[0004] Then, based on the information collected in this way, a determination of normal / abnormal of the operating state of the wind turbine is made. And when an abnormality determination is made, an alert is issued, and an action corresponding to that level is executed. And depending on the level of the alert, measures are taken such as stopping the operation of the wind turbine, dispatching a worker to the site to take necessary measures, resetting the alert, and resuming the operation.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, even when a high-level alert is issued, the operation is often resumed only based on the confirmation by the five senses (mainly visual observation) of the workers actually dispatched to the site, or it may turn out to be a false alarm in the first place. The interruption period from when the operation of the wind turbine stops until it resumes contributes to the decrease in the equipment operation rate and the increase in the lost power generation output. Therefore, it is desirable that the situation of dispatching workers to the site be limited to cases involving specific operations. In addition, in the case of an offshore-installed wind turbine, depending on the sea state, it may be difficult for workers to access the wind turbine, resulting in a longer interruption period of operation and a further increase in the lost power generation output.

[0007] Embodiments of the present invention have been made in consideration of such circumstances, and an object thereof is to provide a diagnostic technique for a wind turbine that can be implemented without dispatching workers.

Means for Solving the Problems

[0008] A diagnostic device for a wind turbine according to an embodiment is a diagnostic device for a wind turbine having a nacelle that houses at least a rotor shaft for transmitting rotational energy converted from the flow energy of wind and a generator for converting the rotational energy into electrical energy, the diagnostic device including: a transmission unit that transmits operation information of vibration means for vibrating a structure disposed in the nacelle; a reception unit that receives detection data from each of a plurality of vibration sensors installed on the structure; and an analysis unit that performs frequency analysis on the received detection data, wherein the vibration means accommodated inside the nacelle, and is impact means for directly striking the structure to apply an impact force, and further includes a work robot that supports the impact means in the internal space of the nacelle and variably sets its working position and working posture, and a drive unit that inputs the operation information specifying the working position and the working posture and outputs a drive signal for the work robot, and the work robot is a multi-joint arm or a drone tendency or the like. , front The excitation means includes a cylindrical body that houses the tower supporting the nacelle at the top and supports it so as to be displaceable in the longitudinal direction, a motor provided on the cylindrical body and driven to rotate, and a rack and pinion that converts the rotational motion of the motor into the linear motion of the tower.

Advantages of the Invention

[0009] According to the embodiment of the present invention, a wind turbine diagnosis technique that can be implemented without dispatching workers is provided.

Brief Description of the Drawings

[0010]

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Best Mode for Carrying Out the Invention

[0011] (First Embodiment) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an overall view of a windmill 20 to which an embodiment of the present invention is applied. FIG. 1(A) shows an example of a fixed-type offshore installation method, and FIG. 2(B) shows an example of a floating-type offshore installation method. Thus, the windmill 20 includes blades 25, a tower 26, a nacelle 30, and a hub 22.

[0012] The blades 25 are radially arranged so as to be connected to a rotor shaft 27 (FIG. 2) by a hub 22. These blades 25 have their pitch angles adjusted with respect to the wind inflow direction so that the kinetic energy of the wind can be efficiently converted into rotational energy. A drive mechanism (not shown) such as a motor, a brake, and an emergency power source for adjusting this pitch angle is provided inside the hub 22. The tower 26 is built vertically on the upper surface of a foundation 28 that is built on the seabed and exposed above the sea surface. In the embodiment of FIG. 1, the application to the windmill 20 using an offshore installation method is exemplified, but it is not limited thereto and can also be applied to onshore windmills.

[0013] FIG. 2 is an internal conceptual view of a nacelle 30 in which a mechanism unit 40 in a diagnostic device (hereinafter simply referred to as a “diagnostic device”) for a windmill according to each embodiment is installed. Thus, the nacelle 30 is provided at the top of the tower 26 via a yaw drive unit 23 that automatically causes the rotor shaft 27 to follow the wind direction. And inside this tower 26, a lifting means 24 for transferring an article or a worker that has been transported by sea and landed on the foundation 28 into the nacelle 30 is provided.

[0014] And various structures 33 are accommodated in this nacelle 30. Such structures 33 include a main bearing 33a that supports the rotor shaft 27, a speed increaser 33b that is connected to the end of the rotor shaft 27 to increase the rotational speed, a generator 33c that converts rotational energy into electrical energy, a conversion circuit 33e that modulates and transforms the output of the generator 33c to obtain an external output 29 of power that matches the system frequency and system voltage, and a transmission circuit 33d that is connected to a plurality of vibration sensors 34 installed on these structures 33 (33a, 33b, …) to aggregate each detection data 43 and transmit it externally. Here, as the vibration sensor 34, an acceleration sensor is exemplified, but it is not particularly limited.

[0015] In the mechanism part 40 of the diagnostic apparatus according to the first embodiment, as a vibration exciting means for the structures 33 (33a, 33b, …), a striking means 45 that directly strikes these structures 33 to apply an impact force is adopted. Further, this mechanism part 40 includes a working robot 46 that supports the striking means 45 in the internal space 47 of the nacelle 30 and variably sets at least one of its working position and working posture, and a driving part 49 that inputs operation information 36 designating the working position and working posture of the striking means 45 and outputs a driving signal for the working robot 46.

[0016] Here, the working robot 46 is not limited to the articulated arm shown in the figure, and any device that can operate the striking means 45 can be appropriately adopted. Also, the striking means 45 is not limited to the hammer shown in the figure, and any device that can directly strike the structure 33 to apply an impact force can be appropriately adopted. Regarding the case where local deformation occurs in the structure 33 or the entire device shakes, etc., by applying an impact force with the striking means 45, abnormal detection can be performed from the change in the natural vibration frequency of the response vibration.

[0017] Also, the multi-joint arm (working robot 46) is configured to move along the rail 19 at its base end portion, and can move the nacelle 30 internally over a wide range. Further, as the configuration of the rail 19, not only traveling but also a three-dimensional movement configuration combining a lateral movement and a telescopic mechanism in the vertical direction can be adopted. Note that the multi-joint arm (working robot 46) may be provided on a mobile robot (not shown) instead of the rail 19.

[0018] Also, the working robot 46 can support the striking means 45 not only inside the nacelle 30 but also inside the tower 26 or inside the hub 22. In this case, it is possible to diagnose the tightening condition of the bolts at the joints of the tower 26 and the structures 33 arranged inside thereof. Further, image data of a monitoring camera (not shown) installed inside the nacelle 30 may be acquired to monitor whether the striking means 45 vibrating the structure 33 is performing a strike as expected.

[0019] FIG. 3 is a block diagram of the control unit 10 in the wind turbine diagnostic device according to the first embodiment. As described above, the control unit 10 of the diagnostic device includes a transmission unit 21 that transmits operation information 36 of the vibration means (striking means 45) that vibrates the structure 33, a reception unit 15 that receives detection data 43 from each of a plurality of vibration sensors 34 installed on the structure 33 (33a, 33b...), and an analysis unit 11 that performs frequency analysis on the detection data 43.

[0020] FIG. 4(A) shows a specific example in which the structure 33 has no change from the initial state and the operating state of the wind turbine 20 is determined to be normal from frequency analysis. FIG. 4(B) shows a specific example in which the operating state of the wind turbine 20 is determined to be abnormal from frequency analysis due to the aging deterioration of the structure 33.

[0021] When an impact force is applied to the structure 33, this structure 33 vibrates at its natural frequency 32 (32a, 32b) (Fig. 6). This natural frequency 32 is determined by the rigidity of the structure 33 itself and the rigidity due to the tightening of the fixing bolts 37. By inputting the detection data 43 of the vibration sensor 34 into the analysis unit 11 and performing frequency analysis using the input of the operation information 36 of the striking means 45 as a trigger, the natural frequency 32 of the structure 33 can be known.

[0022] Fig. 5 is a graph showing the detection data 43 of the vibration sensor 34 installed on the structure 33 vibrated by the exciting means (striking means 45). Fig. 6 is a graph showing the frequency analysis data 35 of the received detection data 43. If there is a crack 38 in the structure 33 (Fig. 4) or the fixing bolt 37 is loose, the rigidity decreases, and the natural frequency 32 also decreases from the code 32a to the code 32b. In this way, by comparing the natural frequencies 32, it is possible to distinguish and detect a normal state in which soundness is maintained and an abnormal state in which soundness is not maintained.

[0023] Returning to Fig. 3 to continue the explanation. The control unit 10 of the diagnostic device further includes a registration unit 31 that links and registers the frequency analysis data 35 to the corresponding operation information 36, and a diagnostic unit 16 that compares two or more frequency analysis data 35 registered at different times with the common operation information 36 and diagnoses the soundness.

[0024] Furthermore, the operation information 36 transmitted from the transmission unit 21 is also registered in this registration unit 31. The striking means 45 can be operated over time with the common operation information 36, and the frequency analysis data of the detection data 43 received from each of the vibration sensors 34 can be accumulated in this registration unit 31. Since this frequency analysis data changes according to the aging deterioration of the corresponding structure 33, the diagnostic unit 16 can determine the normal / abnormal state of the operation state of the windmill.

[0025] Furthermore, the control unit 10 of the diagnostic apparatus includes an operation unit 18 that arbitrarily operates the transmitted operation information 36 to set the working position and working posture of the striking means 45. Thereby, even when the detection data 43 that can be analyzed from the vibration sensor 34 cannot be obtained with the pre-registered operation information 36, the position and posture of the striking means 45 can be corrected to apply an impact force again.

[0026] In addition, in the first embodiment, an example is given in which the structure 33 is vibrated by using a striking means 45 (hammer) as a vibration means supported by a work robot 46 (multi-joint arm). However, the present invention is not limited to this, and a vibration means can be provided in a drone flying inside the nacelle 30, and the drone can approach and vibrate at an arbitrary position of the structure 33.

[0027] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. 7 (refer to FIG. 3 as appropriate). FIG. 7 is an operation conceptual diagram of the nacelle vibrated by the diagnostic apparatus of the wind turbine 20 according to the second embodiment. In FIG. 7, parts having the same configuration or function as those in FIG. 2 are denoted by the same reference numerals, and redundant explanations are omitted. In the second embodiment, the natural frequency 32 of the structure 33 that freely vibrates due to its own inertia is analyzed by suddenly braking the rotational motion.

[0028] The first vibration means in the second embodiment has a function of suddenly braking the rotational motion 51 of the blade 25. The drive unit 49 that has acquired the operation information 36 for executing such a function outputs the following drive signal. That is, the pitch control drive motor of the blade 25 is operated to rotate the blade 25, and then this pitch control drive motor is suddenly stopped.

[0029] Then, for the detection data 43 (Fig. 5) of the vibration sensor 34, using the stop command to the brake that executes this emergency stop as a trigger, the vibration response is frequency-analyzed. Then, the natural frequency 32b is obtained from the frequency analysis data 35 (Fig. 6), and a diagnosis regarding soundness is performed by comparing it with the natural frequency 32a in a sound state (the case in Fig. 6 indicates "abnormal"). According to the first excitation means (the sudden braking of the rotational motion 51 of the blade 25) in the second embodiment, mainly, abnormalities such as material defects can be detected from the change in the natural frequency 32 of the torsional vibration of the blade 25.

[0030] The second excitation means in the second embodiment has a function of suddenly braking the rotational motion 52 of the rotor shaft 27. The drive unit 49 that has acquired the operation information 36 for executing such a function outputs the following drive signal. That is, with the rotor shaft 27 rotating by wind power, a brake is applied to stop the rotation of the rotor shaft 27.

[0031] Then, due to the inertia of the blade 25 at the time of stopping, the wind turbine 20 vibrates, and for the detection data 43 of the vibration sensor 34, using the stop command to the brake that executes this emergency stop as a trigger, the vibration response is frequency-analyzed. Then, the natural frequency 32 is obtained from the frequency analysis data 35, and a diagnosis regarding soundness is performed by comparing it with the natural frequency in a sound state. According to the second excitation means (the sudden braking of the rotational motion 52 of the rotor shaft 27) in the second embodiment, abnormalities can be detected from the change in the natural frequency 32 for vibrations where the entire device shakes or vibrations where the entire tower shakes.

[0032] The third excitation means in the second embodiment has a function of suddenly braking the rotational motion 53 of the nacelle 30. The drive unit 49 that has acquired the operation information 36 for executing such a function outputs the following drive signal. That is, the yaw control drive motor of the nacelle 30 is operated to rotate the nacelle 30, and then this yaw control drive motor is suddenly stopped.

[0033] Then, due to the inertia of the nacelle 30 at the time of stop, the wind turbine 20 vibrates. For the detection data 43 of the vibration sensor 34, a vibration response is frequency-analyzed with a stop command to the brake that executes this sudden stop as a trigger. Then, the natural frequency 32 is obtained from the frequency analysis data 35, and a diagnosis regarding soundness is performed by comparing it with the natural frequency in a sound state. According to the third excitation means (sudden braking of the rotational operation 53 of the nacelle 30) in the second embodiment, it is possible to detect an abnormality from a change in the natural frequency regarding vibrations in which the entire device shakes or vibrations in which the entire tower shakes.

[0034] (Third Embodiment) Next, the third embodiment of the present invention will be described with reference to FIG. 8. FIG. 8 is a conceptual diagram of the operation of the nacelle 30 that the diagnostic device of the wind turbine 20 according to the third embodiment vibrates. In FIG. 8, parts having the same configuration or function as those in FIG. 1 are denoted by the same reference numerals, and duplicate explanations are omitted. The excitation means in the third embodiment has a function of changing the tension of the mooring cable 58 that moors the floating body 56 of the wind turbine 20 and the undersea foundation 59.

[0035] From the equilibrium position of the wind turbine 20 floating on the sea surface shown by the broken line in FIG. 8, one tension adjustment unit 57 is operated to increase the tension of one mooring cable 58. Then, the wind turbine 20 transitions from the equilibrium position of the broken line to the inclined state of the solid line. When the tension increased above is released from this state, the blades 25, the main body of the nacelle 30, and the structure 33 vibrate freely.

[0036] The tension adjustment unit 57 that has acquired such operation information 36 operates as follows. That is, the tension of one mooring cable 58 that has a constant tension in the broken line state is released. Or, after temporarily increasing this tension, it is released. Then, for the detection data 43 of the vibration sensor 34, a vibration response is frequency-analyzed with the release command as a trigger. Then, the natural frequency 32 is obtained from the frequency analysis data 35, and a diagnosis regarding soundness is performed by comparing it with the natural frequency 32 in a sound state. According to the excitation means (release of the tension of the mooring cable 58) in the third embodiment, it is possible to detect an abnormality such as loosening from a change in the natural frequency regarding vibrations in which the entire device shakes or vibrations in which the entire tower shakes.

[0037] (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. 9. FIG. 9 is a conceptual diagram of a vibration means in a diagnostic device for a windmill 20 according to the fourth embodiment. In FIG. 9, parts having the same configuration or function as those in FIG. 1 are denoted by the same reference numerals, and redundant explanations are omitted.

[0038] The vibration means in the fourth embodiment includes a cylindrical body 54 that houses the tower 26 inside and supports it so as to be displaceable in the longitudinal direction, a motor 48 provided on the cylindrical body 54 and driven to rotate, and a rack and pinion 44 that converts the rotational motion of the motor 48 into a linear motion of the tower 26. With this configuration, the tower 26 that supports the nacelle 30 at the top can be forced to vibrate in the vertical direction.

[0039] Note that the motor 48 applied to the fourth embodiment can be diverted to a generator that converts the relative insertion and extraction motion of the tower 26 and the cylindrical body 54 coupled via the elastic member 55 in accordance with the vertical movement of the wave into electrical energy. Further, although the fourth embodiment has been described by exemplifying a floating type offshore installation method (see FIG. 1(B)), it can also be adopted for a fixed type offshore installation method (see FIG. 1(A)) or an onshore installation method.

[0040] The steps of the diagnostic method for a windmill and the algorithm of the diagnostic program for a windmill according to the embodiment will be described based on the example of the flowchart in FIG. 10 (refer to FIGS. 2 and 4 as appropriate). First, the structure 33 disposed in the nacelle 30 is vibrated by transmitting the operation information 36 of the vibration means (S11). Next, the detection data 43 is received from each of the plurality of vibration sensors 34 installed on the structure 33 (S12). Next, the received detection data 43 is subjected to frequency analysis (S13). Then, the positions of the natural frequencies 32 in the obtained frequency analysis data 35 and the frequency analysis data 35 in the initial state that has already been accumulated are compared (S14, S15 Yes / No), and a normal / abnormal determination regarding the soundness of the windmill is performed (S16, S17, END).

[0041] According to the wind turbine diagnostic device of at least one of the above-described embodiments, by performing frequency analysis on the detection data of the vibration sensor when the structure is excited, it is possible to diagnose the wind turbine without dispatching a worker.

[0042] Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.

[0043] The wind turbine diagnostic device described above includes a control device in which a processor such as a dedicated chip, FPGA (Field Programmable Gate Array), GPU (Graphics Processing Unit), or CPU (Central Processing Unit) is highly integrated, a storage device such as ROM (Read Only Memory) and RAM (Random Access Memory), an external storage device such as HDD (Hard Disk Drive) and SSD (Solid State Drive), a display device such as a display, an input device such as a mouse and a keyboard, and a communication I / F, and can be realized with a hardware configuration using an ordinary computer. Therefore, the components of the wind turbine diagnostic device can also be realized by a computer processor and can be operated by a wind turbine diagnostic program.

[0044] Also, the wind turbine diagnostic program is provided by being pre-embedded in a ROM or the like. Alternatively, this program may be stored and provided in a computer-readable storage medium such as a CD-ROM, CD-R, memory card, DVD, flexible disk (FD), etc. in an installable or executable file format.

[0045] Moreover, the diagnostic program for the wind turbine according to this embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Further, the diagnostic device for the wind turbine can also be configured by connecting separate modules that independently exhibit each function of the components to each other via a network or a dedicated line and combining them.

Explanation of Reference Numerals

[0046] 10... Control unit, 11... Analysis unit, 15... Reception unit, 16... Diagnosis unit, 18... Operation unit, 19... Rail, 20... Wind turbine, 21... Transmission unit, 22... Hub, 23... Yaw drive unit, 24... Lifting means, 25... Blade, 26... Tower, 27... Rotor shaft, 28... Foundation, 29... External output, 30... Nacelle, 31... Registration unit, 32(32a, 32b)... Natural frequency, 33... Structure, 33a... Main bearing (structure), 33b... Speed increaser (structure), 33c... Generator (structure), 33d... Transmission circuit (structure), 33e... Conversion circuit (structure), 34... Vibration sensor, 35... Frequency analysis data, 36... Operation information, 37... Fixed bolt, 38... Crack, 40... Mechanism unit, 43... Detection data, 44... Pinion, 45... Striking means (vibrating means), 46... Work robot, 47... Internal space, 48... Motor, 49... Drive unit, 51... First rotational operation, 52... Second rotational operation, 53... Third rotational operation, 54... Cylindrical body, 55... Elastic member, 56... Floating body, 57... Tension adjustment unit, 58... Mooring cable, 59... Foundation.

Claims

1. A diagnostic device for a wind turbine having a nacelle that houses at least a rotor shaft for transmitting rotational energy converted from the kinetic energy of wind flow and a generator for converting the rotational energy into electrical energy, a transmission unit that transmits operation information of vibration means for vibrating a structure disposed in the nacelle; a reception unit that receives detection data from each of a plurality of vibration sensors installed on the structure; and an analysis unit that performs frequency analysis on the received detection data. The vibration means is a striking means that is housed inside the nacelle and directly strikes the structure to apply an impact force. Further, a work robot that supports the striking means in the internal space of the nacelle and variably sets its working position and working posture; and a drive unit that inputs the operation information designating the working position and the working posture and outputs a drive signal for the work robot. The work robot is a diagnostic device for a wind turbine that is a multi-joint arm or a drone.

2. A diagnostic device for a wind turbine having a nacelle that houses at least a rotor shaft for transmitting rotational energy converted from the kinetic energy of wind flow and a generator for converting the rotational energy into electrical energy, a transmission unit that transmits operation information of vibration means for vibrating a structure disposed in the nacelle; a reception unit that receives detection data from each of a plurality of vibration sensors installed on the structure; and an analysis unit that performs frequency analysis on the received detection data. The vibration means includes a cylindrical body that houses the tower supporting the nacelle at the top inside and supports it so as to be displaceable in the longitudinal direction; a motor provided on the cylindrical body and driven to rotate; and a rack and pinion that converts the rotational motion of the motor into a linear motion of the tower. A diagnostic device for a wind turbine having a function of forcibly vibrating the tower in the longitudinal direction.

3. In the wind turbine diagnostic device according to claim 1 or claim 2, a registration unit that links and registers the data of the frequency analysis to the corresponding operation information; a diagnostic unit that compares two or more pieces of the frequency analysis data registered at different times with the common operation information and diagnoses the soundness. A wind turbine diagnostic device comprising:

4. A diagnostic method for a wind turbine having a nacelle that houses at least a rotor shaft that transmits rotational energy converted from the flow energy of wind and a generator that converts the rotational energy into electrical energy, a step of transmitting operation information of vibration means that vibrates a structure disposed in the nacelle; a step of receiving detection data from each of a plurality of vibration sensors installed on the structure; a step of performing frequency analysis on the received detection data, wherein the vibration means is housed inside the nacelle and is a striking means that directly strikes the structure to apply an impact force, Furthermore, in the internal space of the nacelle, the striking means is supported by a work robot that variably sets its working position and working posture, the operation information designating the working position and the working posture is input, and a drive signal of the work robot is output, A diagnostic method for a wind turbine, wherein the work robot is a multi-joint arm or a drone.

5. A diagnostic method for a wind turbine having a nacelle that houses at least a rotor shaft that transmits rotational energy converted from the flow energy of wind and a generator that converts the rotational energy into electrical energy, a step of transmitting operation information of vibration means that vibrates a structure disposed in the nacelle; a step of receiving detection data from each of a plurality of vibration sensors installed on the structure; including the step of performing frequency analysis on the received detection data; The vibration excitation means includes: a cylindrical body that houses a tower supporting the nacelle at the top and supports it so as to be displaceable in the longitudinal direction; a motor provided on the cylindrical body and driven to rotate; a rack and pinion that converts the rotational motion of the motor into the linear motion of the tower; and a diagnostic method for a wind turbine having a function of forcibly vibrating the tower in the longitudinal direction. **Claim 6** A diagnostic program for a wind turbine having a nacelle that houses at least a rotor shaft for transmitting rotational energy converted from the flowing energy of wind and a generator for converting the rotational energy into electrical energy, wherein a computer performs a step of transmitting operation information of vibration excitation means that vibrates a structure disposed in the nacelle, a step of receiving detection data from each of a plurality of vibration sensors installed on the structure, and a step of performing frequency analysis on the received detection data; the vibration excitation means is impact means that is housed inside the nacelle and directly strikes the structure to apply an impact force, and further in the internal space of the nacelle, the impact means is supported by a work robot that variably sets its working position and working posture, the operation information specifying the working position and the working posture is input, and a drive signal for the work robot is output, and the work robot is a multi-joint arm or a drone. **Claim 7** A diagnostic program for a wind turbine having a nacelle that houses at least a rotor shaft for transmitting rotational energy converted from the flowing energy of wind and a generator for converting the rotational energy into electrical energy, The step of transmitting the operation information of the vibration means for vibrating the structure disposed in the nacelle The step of receiving detection data from each of a plurality of vibration sensors installed in the structure Including the step of performing frequency analysis on the received detection data The vibration means is A cylindrical body that houses the tower that supports the nacelle at the top and supports it so as to be displaceable in the longitudinal direction A motor provided on the cylindrical body and driven to rotate A rack and pinion that converts the rotational motion of the motor into the linear motion of the tower, and has A diagnostic program for a wind turbine having a function of forcibly vibrating the tower in the longitudinal direction

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