Wind turbine generator variable pitch bearing fault simulation experiment platform and monitoring method

Abstract

The invention provides a wind turbine generator variable-pitch bearing fault simulation experiment platform and a monitoring method, relates to the technical field of wind turbine generator equipment, and can equivalently simulate the operation and load states of a variable-pitch bearing, realize various loading modes such as axial, radial and torsion, and improve the test efficiency. And vibration signals, sound signals and strain signals of the prefabricated faulty slewing bearing are monitored in real time under different load conditions, and various damage characteristics of the prefabricated faulty slewing bearing are obtained by analyzing the vibration signals, the sound signals and the strain signals, so that health diagnosis and fault early warning of the variable pitch bearing part of the wind turbine generator are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine equipment, and in particular to a wind turbine variable pitch bearing fault simulation experimental platform and a monitoring method. Background Art

[0002] With the national goals of "carbon peak" and "carbon neutrality", my country's energy structure transformation work is bound to be promoted. As an important clean energy, wind resources play a vital role in reducing carbon emissions. Driven by the "dual carbon" goals, wind turbine technology has been increasingly valued by the country. High-power wind turbines on land and shallow waters and deep-sea floating wind turbines have ushered in major development opportunities, and the installed capacity of wind turbines across the country has exploded. According to statistics from the National Energy Administration, my country's new installed capacity of renewable energy in 2022 will be 152 million kilowatts, accounting for 76.2% of the country's new installed power generation capacity, and has become the main body of my country's new installed power capacity. Among them, wind power will add 37.63 million kilowatts, with a cumulative installed capacity of 365 million kilowatts.

[0003] The variable pitch bearing is installed between the blades and the hub of the wind turbine generator, and plays the role of connecting the rotor hub and the rotor blades, controlling the windward angle of the blades, controlling the speed of the wind rotor and the output power of the wind turbine. The working conditions of the variable pitch bearing are complex, and generally need to have good wear resistance, corrosion resistance, self-sealing performance, UV resistance, impact resistance, etc., to meet its long-term operation requirements under environmental conditions such as high impact loads and alternating stresses. During the operation of the wind turbine, the speed of the variable pitch bearing usually does not exceed 5r / min, which is an incomplete rotation (the rotation range is 0°-90°, and the normal rotation angle is 0°~25°); but the load it bears is relatively complex. The variable pitch bearing is subjected to radial loads, axial loads and a large overturning moment generated by the force arm of the wind turbine blades. Because the variable pitch bearing is subject to frequent heavy load conditions and a variety of complex environmental factors, it is prone to fracture, wear, bonding, etc. Damage and failure of the variable pitch bearing will cause the blades to rotate unbalanced, resulting in a reduction in the output power of the generator. In severe cases, it may even cause the variable pitch bearing to break, causing a catastrophic impact on the generator and the entire wind power generation system. At present, the formation mechanism of pitch bearing failure is still unclear. Therefore, theoretical analysis and experimental simulation are used to explore the failure mechanism of pitch bearing. At the same time, combined with advanced sensors, data transmission, fault diagnosis and data models, a wind turbine pitch bearing fault simulation experimental platform and monitoring method are developed. It is of great significance for the accurate and reliable fault monitoring and early warning of pitch bearings and the improvement of maintenance efficiency during the operation stage of wind turbines.

[0004] Patent No. CN202310467067.5 discloses a bearing fault simulation test bench. By setting up a load-bearing unit that can carry different weights, it can match different weight counterweights to simulate the vibration response of the bearing under different loads. It is equipped with bearing parts with multiple fault types and severity levels, which can simulate the vibration response of the bearing under different fault conditions. However, the device can only detect the vibration response and cannot detect signals such as sound and strain. Patent No. CN202122419630.0 discloses a rolling bearing fault simulation test bench. This test bench is coaxially adjustable and avoids the influence of motor vibration on bearing fault testing. The test data of the bearing test assembly is ensured to be obvious through the tension adjustment mechanism. At the same time, multiple mechanical faults can be combined for research. However, the device only involves radial loading, but in actual working conditions, the loading mode of the bearing is mostly a composite loading mode. Patent No. CN202311074525.5 discloses a bearing testing technology field, especially an outer ring rotating bearing loading test device, which can simulate the outer ring rotation of the test bearing, radial load, bending moment loading and other complex actual use conditions, but the device does not involve axial loading. The main problems of the existing bearing fault simulation test bench are: except for the vibration signal, other signal collection such as sound and strain are not reflected, and secondly, the loading conditions are mostly single radial loading, and axial and composite loading are not involved. Summary of the invention

[0005] In order to solve the shortcomings of the above-mentioned prior art, the present invention provides a wind turbine variable pitch bearing fault simulation experimental platform and monitoring method, which can equivalently simulate the operation and load state of the variable pitch bearing, realize multiple loading modes such as axial, radial and torsional, and monitor its vibration signal, sound signal and strain signal in real time under different load conditions. By analyzing the vibration signal, sound signal and strain signal, various damage characteristics of the prefabricated fault slewing bearing are obtained, thereby realizing the health diagnosis and fault warning of the variable pitch bearing components of the wind turbine.

[0006] The present invention is achieved through the following technical solutions: A wind turbine variable pitch bearing fault simulation experimental platform, characterized in that it comprises a simulated blade, a control system, and a basic platform, wherein a support frame is arranged on the basic platform, a radial second displacement frame is assembled in the support frame, a radial first displacement frame is movably assembled in the radial second displacement frame through a radial first displacement guide column, the radial first displacement frame is connected to a radial first loading component, and the radial first loading component drives the radial first displacement frame to move in a second direction in the radial second displacement frame; a radial first displacement block is assembled in the radial first displacement frame through a radial second displacement guide column, and the radial first displacement block is connected to the radial second loading component, and the radial second loading component drives the radial first displacement block to move in the radial first displacement frame along the radial second displacement guide column along the first direction; the first direction and the second direction are perpendicular; one end of the simulated blade is assembled in the radial first displacement block and connected to the torque loading component, and the other end is connected to a slewing bearing, connected to a driving component, and supported by a slewing bearing seat; a collection component is assembled on the slewing bearing; a torque loading support is arranged outside the torque loading component, one end of the torque loading support is connected to the axial loading component through an axial loading universal block, and the other end is connected to the simulated blade.

[0007] Furthermore, the radial first displacement block is in contact with the upper and lower ends of the radial first displacement frame.

[0008] Furthermore, the radial second displacement frame is assembled in the support frame through an axial displacement guide column; one end of the simulated blade is assembled in the radial first displacement block through a fixed bearing.

[0009] Furthermore, the torque loading assembly includes a torque motor and a planetary reducer I, the torque motor is connected to the planetary reducer I, the planetary reducer I is connected to the simulated blade through a coupling and a connecting rod, and a torque speed sensor is installed on the connecting rod.

[0010] Furthermore, the radial first loading component adopts electric cylinder I; the radial second loading component adopts electric cylinder II; and the axial loading component adopts electric cylinder III.

[0011] Furthermore, the telescopic rod of the electric cylinder I is equipped with a tension pressure sensor I; the telescopic rod of the electric cylinder II is equipped with a tension pressure sensor II, and the telescopic rod of the electric cylinder III is equipped with a tension pressure sensor III.

[0012] Furthermore, the acquisition component includes a vibration signal acquisition component, a strain signal acquisition component and a sound acquisition component.

[0013] Furthermore, the vibration signal acquisition component includes a vibration sensor and a 24-channel vibration collector; the strain signal acquisition component includes an optical fiber sensor and a demodulator; and the sound acquisition component includes a sound sensor.

[0014] Furthermore, the driving assembly includes a driving motor and a planetary reducer II, the driving motor is connected to the planetary reducer II, and the planetary reducer II drives the simulated blade to rotate by cooperating with the gear in the slewing bearing through the driving pinion.

[0015] A wind turbine variable pitch bearing fault simulation experimental monitoring method comprises the following steps: Step 1, start the experimental platform to perform torque loading, axial loading, radial horizontal loading, and vertical loading on the simulated blade; Step 2: collecting the vibration signal, strain signal and sound signal of the slewing bearing during the loading process in step 1 through the acquisition component, and transmitting them to the control system to obtain the main frequency of the measured vibration signal, strain signal and sound signal; Step 3: Calculate the characteristic frequency using the fault characteristic frequency formula. The fault characteristic frequency formula is as follows: Outer race fault characteristic frequency: ; Inner race fault characteristic frequency: ; Rolling element failure characteristic frequency: ; Cage failure characteristic frequency: ; in is the number of rolling elements, is the rolling element diameter, is the raceway pitch diameter, is the bearing contact angle, Indicates frequency conversion; Step 4: If the characteristic frequency obtained in step 3 matches one or more main frequencies in the signal measured in step 2, the fault location can be obtained.

[0016] The working principle of the present invention is as follows: The simulated blades and the slewing bearings rotate under the drive of the driving assembly, and the torque loading assembly is connected to the simulated blades, so that the torque load is directly transmitted to the simulated blades, thereby realizing torque loading on the simulated blades; the radial first displacement frame is connected to the radial first loading assembly, and the radial first loading assembly drives the radial first displacement frame to move along the second direction in the radial second displacement frame, and contacts with the radial first displacement block, so as to transfer the load equally from the radial first displacement frame to the radial first displacement block, and then from the radial first displacement block to the simulated blades, thereby realizing load application on the simulated blades in the second direction; the radial first displacement block is assembled in the radial first displacement frame through the radial second displacement guide column, and the radial first displacement block is connected to the radial second loading assembly and driven by the radial second loading assembly The radial first displacement block moves along the radial second displacement guide column in the radial first displacement frame along the first direction, the simulated blade will have a slight deformation, and the load is equally transmitted to the simulated blade by the radial first displacement block; the axial loading component applies axial thrust to the torque loading support through the axial loading universal block. Since the torque loading support is connected to the simulated blade, the axial loading of the simulated blade is realized. The vibration signal, strain signal and sound signal of the slewing bearing in different axial and radial directions and different load processes such as torque of the slewing bearing are collected by the collection component, and transmitted to the control system. Then, the control system calculates and analyzes the characteristic frequency through the fault analysis frequency formula and matches one or more main frequencies of the measured vibration signal, strain signal and sound signal, so as to obtain the specific fault position of the bearing.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. It can simulate the operation and load state of the variable pitch bearing equivalently, and realize real-time monitoring of its vibration signal, sound signal and strain signal under different load conditions such as axial, radial and torsional. By analyzing the vibration signal, sound signal and strain signal, various damage characteristics of the prefabricated fault slewing bearing can be obtained, thereby realizing the health diagnosis and fault warning of the variable pitch bearing components of the wind turbine; 2. The present invention adopts a radial water first displacement frame, a radial second displacement frame, a support frame and a radial first displacement block, and realizes torque loading, axial loading, radial horizontal loading and vertical loading with a more compact structure through nesting between the frames, and realizes composite loading of four degrees of freedom, which is closer to the actual working condition; 3. In the present invention, multiple loading modes can be loaded independently or in combination through nesting between frames, and the four loading modes do not affect each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 for Figure 1 Front view; Figure 3 for Figure 1 Top view; Figure 4 for Figure 1 Schematic diagram of the structure of the middle part; Figure 5 This is a health diagram of the monitoring status of the present invention; Figure 6 This is a schematic diagram of the monitoring status failure of the present invention.

[0019] Figure markings: 1-base platform, 2-drive motor, 3-planetary reducer II, 4-slewing bearing seat, 5-slewing bearing, 6-drive pinion, 7-simulated blade, 8-radial second loading assembly, 9-support frame, 10-radial first loading assembly, 11-tension pressure sensor I, 12-coupling, 13-planetary reducer I, 14-torque motor, 15-torque loading support, 16-axial loading universal block, 17-tension pressure sensor III, 18-axial loading assembly, 19-axial loading bracket, 20-torque speed sensor, 21-tension pressure sensor II, 22-vibration sensor, 23-optical fiber sensor, 24-sound sensor, 25-axial displacement guide column, 26-radial first displacement block, 27-radial second displacement frame, 28-radial first displacement guide column, 29-radial first displacement frame, 30-fixed bearing, 31-radial second displacement guide column, 32-connecting rod. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings of the present invention specification to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1 like Figure 1-Figure 4As shown, a wind turbine variable pitch bearing fault simulation experimental platform includes a simulated blade 7, a control system, and a basic platform 1. A support frame 9 is provided on the basic platform 1. A radial second displacement frame 27 is assembled in the support frame 9. A radial first displacement frame 29 is movably assembled in the radial second displacement frame 27 through a radial first displacement guide column 28. The radial first displacement frame 29 is connected to a radial first loading component 10. The radial first loading component 10 drives the radial first displacement frame 29 to move in the radial second displacement frame 27 along a second direction. The radial first displacement block 26 is assembled in the radial first displacement frame 29 through a radial second displacement guide column 31, and the radial first displacement block 26 is assembled in the radial first displacement frame 29 through a radial second displacement guide column 31. A displacement block 26 is connected to the radial second loading component 8, and the radial first displacement block 26 is driven by the radial second loading component 8 to move along the radial second displacement guide column 31 in the radial first displacement frame 29 along the first direction; the first direction and the second direction are perpendicular; one end of the simulated blade 7 is assembled in the radial first displacement block 26 and connected to the torque loading component, and the other end is connected to the slewing bearing 5, and is connected to the driving component, and is supported by the slewing bearing seat 4; the slewing bearing 5 is equipped with a collection component; a torque loading support 15 is arranged outside the torque loading component, one end of the torque loading support 15 is connected to the axial loading component 18 through the axial loading universal block 16, and the other end is connected to the simulated blade 7.

[0022] The simulated blade 7 and the slewing bearing 5 rotate under the drive of the driving component, and the torque loading component is connected to the simulated blade 7, so the torque load is directly transmitted to the simulated blade 7, thereby realizing the torque loading of the simulated blade 7; the radial first displacement frame 29 is connected to the radial first loading component 10, and the radial first loading component 10 drives the radial first displacement frame 29 to move along the second direction in the radial second displacement frame 27, and contacts with the radial first displacement block 26, so as to transfer the load from the radial first displacement frame 29 to the radial first displacement block 26 equally, and then transfer the load from the radial first displacement block 26 to the simulated blade 7 equally, thereby realizing the load on the simulated blade 7 in the second direction; the radial first displacement block 26 is assembled in the radial first displacement frame 29 through the radial second displacement guide column 31, and the radial first displacement block 26 is connected to the radial second loading component 8, and the radial first displacement block 26 is driven by the radial second loading component 8 to move along the radial second displacement guide column 31 When moving in the first radial displacement frame 29 along the first direction, the simulated blade 7 will be slightly deformed, and the load is equally transmitted to the simulated blade 7 by the first radial displacement block 26; the axial loading component 18 applies axial thrust to the torque loading support 15 through the axial loading universal block 16. Since the torque loading support 15 is connected to the simulated blade 7, the axial loading of the simulated blade 7 is realized, wherein the role of the axial loading universal block 16 is reflected in that when radial loading is performed, the torque loading support 15 will not affect the axial loading when moving radially with the simulated blade 7. The vibration signal, strain signal and sound signal of the slewing bearing 5 in different axial and radial directions and different load processes such as torque of the slewing bearing 5 are collected by the collection component, and transmitted to the control system, and then the control system calculates and analyzes the characteristic frequency through the fault analysis frequency formula to match one or more main frequencies of the measured vibration signal, strain signal and sound signal, and the specific fault position of the bearing can be obtained.

[0023] In this embodiment, the second direction is a vertical direction in the radial direction of the simulated blade 7, and the first direction is a horizontal direction in the radial direction.

[0024] In this embodiment, an axial loading bracket 19 for supporting the axial loading component 18 is provided on the basic platform 1. The control system consists of a control cabinet, related control hardware and software, etc. The control cabinet is designed to be floor-standing, and its operation panel includes a touch screen and buttons such as start, stop, and emergency stop for easy operation. The control system can control the speed, forward and reverse rotation of the drive component, as well as the loading of the radial first loading component 10, the radial second loading component 8, the torque loading component, and the axial loading component 18 through the touch screen. In addition, the control system can also display parameters such as current, speed, and torque in real time. In order to ensure the stability and reliability of the system, corresponding control hardware such as contactors, circuit breakers, and PCBA boards are equipped.

[0025] Furthermore, the first radial displacement block 26 is in contact with the upper and lower ends of the first radial displacement frame 29 .

[0026] In this embodiment, the radial second displacement frame 27 is assembled in the support frame 9 through the axial displacement guide column 25 ; one end of the simulated blade 7 is assembled in the radial first displacement block 26 through the fixed bearing 30 .

[0027] Example 2 This embodiment further elaborates and illustrates the implementation mode of the present invention on the basis of Embodiment 1.

[0028] As an implementation mode of this embodiment, the torque loading assembly includes a torque motor 14 and a planetary reducer Ⅰ13. The torque motor 14 is connected to the planetary reducer Ⅰ13. Through the deceleration mechanism, the load requirement for the torque motor 14 can be reduced, the torque motor 14 can be prevented from being overloaded and damaged, and the life of the torque motor 14 can be extended. The planetary reducer Ⅰ13 is connected to the simulated blade 7 through the coupling 12 and the connecting rod 32, and the torque speed sensor 20 is installed on the connecting rod 32.

[0029] During implementation, the torque motor 14 is started, and a torque load is applied to the simulated blade 7 through the planetary reducer I 13 , the coupling 12 and the connecting rod 32 .

[0030] As an example, the torque loading assembly uses a torque motor 14, which is connected to the simulated blade 7 through the coupling 12, the connecting rod 32. The torque motor 14 is started, and the torque motor 14 applies a torque load to the simulated blade 7 through the coupling 12 and the connecting rod 32.

[0031] As another implementation of this embodiment, the radial first loading assembly 10 adopts electric cylinder I; the radial second loading assembly 8 adopts electric cylinder II; and the axial loading assembly 18 adopts electric cylinder III.

[0032] In this embodiment, electric cylinder I, electric cylinder II and electric cylinder III are all electric cylinders in the prior art.

[0033] As an example, the radial first loading assembly 10 , the radial second loading assembly 8 , and the axial loading assembly 18 are all cylinders.

[0034] Furthermore, the telescopic rod of the electric cylinder I is equipped with a tension pressure sensor I11; the telescopic rod of the electric cylinder II is equipped with a tension pressure sensor II21, and the telescopic rod of the electric cylinder III is equipped with a tension pressure sensor III17.

[0035] During implementation, a tension and pressure sensor Ⅰ11 is installed on the telescopic rod of the electric cylinder Ⅰ, and the electric cylinder Ⅰ is started. The load is applied to the radial first displacement frame 29, and the electric cylinder Ⅰ drives the radial first displacement frame 29 to move along the radial first displacement guide column 28 in the radial second displacement frame 27 along the second direction to contact the radial first displacement block 26, and the load is applied equally to the radial first displacement block 26, and the radial first displacement block 26 transfers the equal load to the simulated blade 7. In this loading process, the tension and pressure sensor Ⅰ11 collects the load applied to the radial first displacement frame 2 9, so as to accurately detect the load on the simulated blade 7 in the second direction; start the electric cylinder II, and the electric cylinder II drives the radial first displacement block 26 to move along the radial second displacement guide column 31 in the radial first displacement frame 29 in the first direction, so that the simulated blade 7 will be slightly deformed, and the load is applied to the radial first displacement block 26, and the radial first displacement block 26 transfers the load equally to the simulated blade 7, and the tension pressure sensor II 21 collects the load applied to the radial first displacement block 26, so as to accurately detect the load on the simulated blade 7 in the first direction. The electric cylinder III applies the axial thrust to the torque loading support 15 through the axial loading universal block 16. Since the torque loading support 15 is rigidly connected to the simulated blade 7, the axial thrust is equally transferred to the simulated blade 7 by the torque loading support 15, thereby realizing the axial loading of the simulated blade 7, and the axial thrust applied to the torque loading support 15 is collected by the tension pressure sensor III 17 installed on the telescopic rod of the electric cylinder III, so as to accurately detect the load on the simulated blade 7 in the axial direction.

[0036] As another implementation of this embodiment, the acquisition component includes a vibration signal acquisition component, a strain signal acquisition component and a sound acquisition component.

[0037] Furthermore, the vibration signal acquisition component includes a vibration sensor 22 and a 24-channel vibration collector; the strain signal acquisition component includes an optical fiber sensor 23 and a demodulator; and the sound acquisition component includes a sound sensor 24.

[0038] During implementation, the vibration signal is collected by the vibration sensor 22 and transmitted to the 24-channel vibration collector for sampling and then transmitted to the control system. The collector can ensure the accuracy of the vibration signal and realize the real-time transmission and display of the vibration signal; the optical fiber sensor 23 collects the strain signal and transmits it to the demodulator for adjustment, adjusts the optical signal to an electrical signal, and samples the signal to obtain strain data for transmission to the control system; the sound sensor 24 captures the sound wave of the slewing bearing 5 during operation and transmits it to the control system after processing, and then the control system calculates and analyzes the fault analysis frequency formula to match one or more main frequencies of the measured vibration signal, strain signal and sound signal, and the specific fault position of the bearing can be obtained.

[0039] As an example, the vibration signal acquisition component can also adopt a vibration analyzer, which integrates functions such as signal acquisition, spectrum analysis, and fault diagnosis; the sound acquisition component includes a microphone array data acquisition instrument. The sound waves emitted by the slewing bearing 5 during operation are propagated to the microphone array in the form of waves. After the microphone captures the sound waves, it converts them into corresponding electrical signals, which are input into the control system after passing through an amplifier, a filter, and an A / D converter; the strain signal can also be collected through existing dynamic and static strain gauges.

[0040] As an example, Figure 5-Figure 6 As shown, Figure 5 The signal of the slewing bearing 5 in a healthy state, Figure 6 is the fault signal of the inner ring raceway crack of the slewing bearing 5, curves 1-4 are vibration signals, curve 5 is the sound signal, and curves 6-11 are strain signals. In contrast, Figure 6 Medium signal amplitude ratio Figure 5 It is larger and contains a lot of impact signals. Therefore, when the slewing bearing 5 fails, the signal amplitude is larger.

[0041] As another implementation method of this embodiment, Figure 2-Figure 3 As shown, the driving assembly includes a driving motor 2 and a planetary reducer II 3. The driving motor 2 is connected to the planetary reducer II 3. Through the reduction mechanism, the load requirement for the driving motor 2 can be reduced, the driving motor 2 can be prevented from being overloaded and damaged, and the life of the driving motor 2 can be extended. The planetary reducer II 3 drives the driving pinion 6 to rotate with the gear in the slewing bearing 5 and the simulated blade 7.

[0042] As an example, the drive assembly may only use the drive motor 2 .

[0043] Example 4 This embodiment further elaborates and supplements the implementation manner of the present invention on the basis of Embodiment 1, Embodiment 2 or Embodiment 3.

[0044] A wind turbine variable pitch bearing fault simulation experimental monitoring method comprises the following steps: Step 1, start the experimental platform to perform torque loading, axial loading, radial horizontal loading, and vertical loading on the simulated blade 7; Step 2: collecting the vibration signal, strain signal and sound signal of the slewing bearing 5 during the loading process in step 1 through the acquisition component, and transmitting them to the control system to obtain the main frequency of the measured vibration signal, strain signal and sound signal; Step 3: Calculate the characteristic frequency using the fault characteristic frequency formula. The fault characteristic frequency formula is as follows: Outer race fault characteristic frequency: ; Inner race fault characteristic frequency: ; Rolling element failure characteristic frequency: ; Cage failure characteristic frequency: ; in is the number of rolling elements, is the rolling element diameter, is the raceway pitch diameter, is the bearing contact angle, Indicates frequency conversion; Step 4: If the characteristic frequency obtained in step 3 matches one or more main frequencies in the signal measured in step 2, the fault location can be obtained.

Claims

1. A wind turbine variable pitch bearing fault simulation experimental platform, characterized by: The invention comprises a simulated blade (7), a control system, and a basic platform (1). The basic platform (1) is provided with a support frame (9). A radial second displacement frame (27) is assembled in the support frame (9). A radial first displacement frame (29) is movably assembled in the radial second displacement frame (27) via a radial first displacement guide column (28). The radial first displacement frame (29) is connected to a radial first loading component (10). The radial first loading component (10) drives the radial first displacement frame (29) to move in a second direction in the radial second displacement frame (27). A radial first displacement block (26) is assembled in the radial first displacement frame (29) via a radial second displacement guide column (31). The radial first displacement block (26) is movably assembled in the radial second displacement frame (27) via a radial first displacement guide column (31). The first radial displacement block (26) is connected to the second loading component (8), and the first radial displacement block (26) is driven by the second radial loading component (8) to move along the second radial displacement guide column (31) in the first radial displacement frame (29) along the first direction; the first direction and the second direction are perpendicular; one end of the simulated blade (7) is assembled in the first radial displacement block (26) and connected to the torque loading component, and the other end is connected to the slewing bearing (5), connected to the driving component, and supported by the slewing bearing seat (4); the slewing bearing (5) is assembled with a collection component; a torque loading support (15) is arranged outside the torque loading component, one end of the torque loading support (15) is connected to the axial loading component (18) through the axial loading universal block (16), and the other end is connected to the simulated blade (7).

2. A wind turbine variable pitch bearing fault simulation experimental platform according to claim 1, characterized in that: The radial first displacement block (26) is in contact with the upper and lower ends of the radial first displacement frame (29).

3. A wind turbine variable pitch bearing fault simulation experimental platform according to claim 1, characterized in that: The radial second displacement frame (27) is assembled in the support frame (9) via an axial displacement guide column (25); one end of the simulated blade (7) is assembled in the radial first displacement block (26) via a fixed bearing (30).

4. A wind turbine variable pitch bearing fault simulation experimental platform according to claim 1, characterized in that: The torque loading assembly comprises a torque motor (14) and a planetary reducer I (13), the torque motor (14) being connected to the planetary reducer I (13), the planetary reducer I (13) being connected to the simulated blade (7) via a coupling (12) and a connecting rod (32), and a torque speed sensor (20) being mounted on the connecting rod (32).

5. A wind turbine variable pitch bearing fault simulation experimental platform according to claim 1, characterized in that: The radial first loading component (10) adopts an electric cylinder I; the radial second loading component (8) adopts an electric cylinder II; and the axial loading component (18) adopts an electric cylinder III.

6. A wind turbine variable pitch bearing fault simulation experimental platform as claimed in claim 5, characterized in that: The telescopic rod of the electric cylinder I is equipped with a tension pressure sensor I (11); the telescopic rod of the electric cylinder II is equipped with a tension pressure sensor II (21); the telescopic rod of the electric cylinder III is equipped with a tension pressure sensor III (17).

7. A wind turbine variable pitch bearing fault simulation experimental platform according to any one of claims 1 to 6, characterized in that: The acquisition component includes a vibration signal acquisition component, a strain signal acquisition component and a sound acquisition component.

8. A wind turbine variable pitch bearing fault simulation experimental platform according to claim 7, characterized in that: The vibration signal acquisition component comprises a vibration sensor (22) and a 24-channel vibration acquisition instrument; the strain signal acquisition component comprises an optical fiber sensor (23) and a demodulator; and the sound acquisition component comprises a sound sensor (24).

9. A wind turbine variable pitch bearing fault simulation experimental platform according to claim 7, characterized in that: The driving assembly comprises a driving motor (2) and a planetary reducer II (3), wherein the driving motor (2) is connected to the planetary reducer II (3), and the planetary reducer II (3) drives the driving pinion (6) and the gear in the slewing bearing (5) to rotate with the simulated blade (7).

10. A wind turbine variable pitch bearing fault simulation experiment monitoring method, which is performed by the experimental platform described in any one of claims 1 to 9, characterized in that: The steps include: Step 1, starting the experimental platform to perform torque loading, axial loading, radial horizontal loading, and vertical loading on the simulated blade (7); Step 2: collecting the vibration signal, strain signal and sound signal of the slewing bearing 5 during the loading process in step 1 through the acquisition component, and transmitting them to the control system to obtain the main frequency of the measured vibration signal, strain signal and sound signal; Step 3: Calculate the characteristic frequency using the fault characteristic frequency formula. The fault characteristic frequency formula is as follows: Outer race fault characteristic frequency: ； Inner Circle Fault characteristic frequency: ； Rolling element failure characteristic frequency: ； Cage failure characteristic frequency: ； in is the number of rolling elements, is the rolling element diameter, is the raceway pitch diameter, is the bearing contact angle, Indicates frequency conversion; Step 4: If the characteristic frequency obtained in step 3 matches one or more main frequencies in the signal measured in step 2, the fault location can be obtained.

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