Large generator set modal test detection device and automatic control system and method

Abstract

The invention belongs to the field of generator set production, and discloses a large generator set modal test detection device and an automatic control system and method.According to the device, the air floatation supporting function and the excitation function are integrated on one device, the dual effects of supporting and excitation force application are achieved, the test precision and the test efficiency are improved, and the test cost is reduced. And high-precision and high-efficiency test requirements of heavy equipment such as a large generator set can be met. According to the automatic control system, through a controller, a proportional control valve, a displacement sensor and a pressure sensor, intelligent adjustment of the piston height and the exciting force is achieved, the testing efficiency and precision are improved, the material and labor cost is reduced, the testing period is shortened, and high economical efficiency and practicability are achieved. According to the invention, the equipment structure can be simplified, the equipment cost is reduced, manpower is saved, the test precision and test efficiency are improved, intelligent control is realized, and the applicability is high; the method is suitable for the electric power construction industry and is used for carrying out modal test detection on the large generator set.

Description

Technical Field

[0001] The invention belongs to the field of generator set production, and specifically relates to a large-scale generator set modal test detection device and an automatic control system and method. Background Art

[0002] Modal test detection methods are usually used to detect generator sets in power construction. Modal test detection is a technical means to determine the modal parameters of the structure through vibration testing methods. Its main purpose is to study the dynamic characteristics of the structure, evaluate the structural strength and reliability of the generator set, and facilitate timely discovery and resolution of equipment defects in generator operation, providing a basis for structural design and optimization in generator set production.

[0003] When performing modal tests on generator sets, two points need to be met: one is to support the generator set, and the other is to apply vibration to the generator set. The traditional ways of supporting and exciting generator sets are: traditional mechanical support or air floating support, and electromagnetic excitation technology. Because traditional mechanical supports (such as springs or rubber pads) will impose additional constraints on the object being tested, affecting the accuracy of the test results, modal tests on generator sets are often carried out using a combination of air floating support and electromagnetic excitation.

[0004] However, the combination of air-floating support and electromagnetic excitation has the following defects: 1. Air-floating support requires a high-pressure gas source and a precision control system. The equipment has a complex structure and high maintenance costs. It is only suitable for testing small components and is difficult to directly apply to large generator sets. 2. High-end electromagnetic excitation equipment is expensive and has poor adaptability to testing large equipment. 3. Air-floating support and electromagnetic excitation devices are usually split designs, which increases the difficulty of operating the equipment and makes it difficult to meet the high-precision and high-efficiency testing requirements of heavy equipment such as large generator sets. Summary of the invention

[0005] In order to solve the above deficiencies in the prior art, the present invention aims to provide a large generator set modal test detection device and an automated control system and method to meet the high-precision and high-efficiency testing requirements for heavy equipment such as large generator sets, and reduce testing and maintenance costs.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows: The present invention provides a large-scale generator set modal test detection device, comprising a supporting seat, a cylinder body, an air source, a piston, an exciting motor and a load-bearing plate; the cylinder body is fixedly arranged on the supporting seat, the interior of the cylinder body is a hollow chamber, the piston comprises a load-bearing plate and a piston cylinder which are fixedly connected, the piston cylinder is sleeved on the outer wall of the cylinder body and is airtightly connected to the cylinder body, the air source is connected to the hollow chamber of the cylinder body through an air supply pipeline and drives the piston to move in a vertical direction, the load-bearing plate is sealed and fixed to the top of the piston cylinder, the exciting motor is arranged between the load-bearing plate and the supporting seat, the exciting motor comprises a stator part and a mover part which are coaxially arranged, the mover part is fixedly connected to the load-bearing plate and outputs an axial exciting force to drive the load-bearing plate to reciprocate vertically, and the stator part is fixedly mounted on the supporting seat and coaxially sleeved on the outer periphery of the mover part.

[0007] As a limitation of the present invention: an airbag ring is arranged between the piston and the outer wall of the cylinder body, the airbag ring is sleeved on the outer periphery of the cylinder body, the upper edge of the airbag ring is fixedly connected to the piston through an upper pressure ring, and the lower edge of the airbag ring is fixedly connected to the cylinder body through a lower pressure plate.

[0008] As a further limitation of the present invention: the excitation motor is a linear motor.

[0009] As another limitation of the present invention: at least one row of vertical mounting grooves is arranged on the outer wall of the cylinder body, each row of vertical mounting grooves includes a plurality of vertical mounting grooves spaced circumferentially along the outer wall of the cylinder body, a plurality of rolling bodies are evenly embedded in each vertical mounting groove, the rolling bodies are exposed in the vertical mounting grooves and in rolling contact with the inner wall of the piston.

[0010] As a further limitation of the present invention: the supporting seat is made of high-strength aluminum alloy material.

[0011] The present invention also provides an automatic control system, including a controller and a proportional control valve; the proportional control valve is fixed on a supporting seat and electrically connected to the controller, and the outlet end of the proportional control valve is connected to an air supply pipeline.

[0012] As a limitation of the present invention: it also includes a displacement sensor and a sensing plate, the sensing plate is fixed on the side of the load-bearing plate facing the supporting seat, the displacement sensor is fixed on the supporting seat at a position corresponding to the sensing plate, the displacement sensor is electrically connected to the controller, and the displacement sensor monitors the piston displacement in real time and feeds back to the controller.

[0013] As a further limitation of the present invention: it also includes a pressure sensor arranged between the excitation motor and the supporting seat, the pressure sensor is electrically connected to the controller to transmit pressure parameters, and the controller is electrically connected to the excitation motor.

[0014] The present invention also provides an automatic control method, which comprises the following steps: S1. Setting of air flotation pressure: Calculate the required air flotation pressure according to the weight of the generator set and set the initial value through the controller; S2. Input the excitation force parameters; input the target excitation force and frequency, and the controller automatically matches the excitation motor current; S3. Turn on the gas source and controller, and the piston will float to the set height; S4. Vibration test: the controller sends a command, and the vibration motor applies the target vibration force at the input frequency for a certain period of time; S5. Data acquisition: record the vibration signal of the generator set through the acceleration sensor and analyze its modal parameters; S6. Automatic adjustment: If the air flotation pressure fluctuation exceeds the limit during the test, the controller dynamically adjusts the opening of the proportional control valve to maintain the air flotation pressure stable; S7. Output the test results.

[0015] As a limitation of the present invention: Step S6 also includes an intelligent adjustment stage, which includes the following contents: Dynamic balance; the displacement sensor monitors the piston height in real time. If a deviation is detected, the controller adjusts the proportional control valve to increase or decrease the air supply to maintain a constant suspension height; Closed-loop control of the exciting force; the pressure sensor monitors the fluctuation of the air flotation pressure, and the controller synchronously adjusts the output force of the exciting motor to ensure the stability of the exciting force amplitude.

[0016] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art: The present invention provides a large-scale generator set modal test detection device, which utilizes an air source to supply air to the hollow chamber of the cylinder through an air supply channel and an air supply pipeline to suspend the piston, thereby lifting the generator set placed on the load-bearing plate to a support height. The overall structure is simple and the cost is low. An exciting motor is used to apply an exciting force to the load-bearing plate, and a modal test is performed on the generator set on the load-bearing plate. The cost is low. The air-floating bearing puts the generator set in a state of near-free and unconstrained operation, reducing the influence of external constraints on the test results, which helps to improve the accuracy of the modal test results. The device integrates air-floating support and excitation functions into one device, simplifies the equipment structure, reduces maintenance costs, achieves the dual effects of support and exciting force application, reduces the preparation work before the test and the operating procedures during the test, is more convenient, improves the test accuracy and test efficiency, and can meet the high-precision and high-efficiency testing requirements of heavy equipment such as large generator sets. The present invention also provides an automated control system, which monitors the displacement of the bearing plate in real time through a displacement sensor, and transmits the displacement signal to the controller for the controller to determine the support height of the piston. If the displacement is caused by the change in the weight of the generator set, the displacement sensor will be fed back to the controller, and the controller adjusts the proportional control valve to increase or decrease the air supply, thereby adjusting the support height of the generator set, maintaining the constant suspension height of the bearing plate, and achieving a precise load-bearing effect, which is convenient for improving the accuracy of the test. The pressure sensor feeds back the air flotation pressure parameter to the controller, and the controller determines whether it is necessary to adjust the frequency and amplitude of the alternating current of the excitation motor according to the preset program and sends an excitation instruction to the excitation motor, thereby controlling the excitation motor to apply the target excitation force to the generator set to ensure the accuracy of the applied excitation force. The system realizes intelligent adjustment of the piston height and excitation force through the controller, proportional control valve, displacement sensor and pressure sensor, improves the test efficiency and accuracy, reduces material and labor costs, and shortens the test cycle. It has high economy and practicality and is more suitable for modal testing of large generator sets.

[0017] In summary, the present invention can simplify the equipment structure, reduce equipment cost, save manpower, improve test accuracy and test efficiency, realize intelligent control, and has high applicability; the present invention is suitable for the electric power construction industry and is used for modal test detection of large generator sets. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Figure 1 It is a schematic cross-sectional structural diagram of an embodiment of the present invention in a front view state; Figure 2 For the embodiment of the present invention Figure 1 Schematic diagram of the cross section along the AA direction; Figure 3 for Figure 1 A magnified schematic diagram of part B; Figure 4 is a schematic diagram of an application structure of an embodiment of the present invention; Figure 5 It is a structural schematic diagram of an automatic control system in an embodiment of the present invention; Figure 6 It is a flowchart of the automatic control method in an embodiment of the present invention.

[0020] In the figure: 1-support seat; 101-installation cavity; 2-cylinder body; 21-hollow chamber; 3-piston; 31-load-bearing plate; 32-piston cylinder; 4-excitation motor; 41-moving part; 42-stator part; 5-air supply channel; 6-air supply pipeline; 7-first support plate; 8-second support plate; 9-mounting ring; 10-ball; 11-air bag ring; 12-upper pressure ring; 13-lower pressure plate; 14-proportional control valve; 15-displacement sensor; 16-sensing plate; 17-generator set; 18-pressure sensor; 19-vertical installation groove; 20-support plate. DETAILED DESCRIPTION

[0021] It should be understood that the large generator set modal test detection device and automatic control system and method described herein are preferred embodiments, which are only used to illustrate and explain the present invention and do not constitute a limitation to the present invention.

[0022] The first exemplary embodiment of the present invention provides a large generator set modal test detection device, such as Figure 1 to Figure 4 As shown, this embodiment includes a support seat 1, a cylinder 2, an air source, a piston 3, an exciting motor 4 and a bearing plate 31. The air source is mainly used to provide high-pressure gas, and its structure is the prior art and is not shown in the figure.

[0023] The support seat 1 is made of high-strength aluminum alloy material and serves as an integrated platform for air-floating bearing and excitation functions. The cylinder body 2 is fixedly mounted on the support seat 1. Specifically, the cylinder body 2 and the support seat 1 are both cylindrical structures. A cylindrical mounting cavity 101 for placing the cylinder body 2 is provided in the support seat 1. A mounting ring 9 extending away from the center of the cylinder body 2 is fixedly provided on the outer periphery of the top of the cylinder body 2. In this embodiment, the cylinder body 2 and the mounting ring 9 are integrally arranged, and the cylinder body 2 is mounted on the top of the support seat 1 through the mounting ring 9. After the cylinder body 2 is mounted on the top of the support seat 1, a gap is left between the bottom end of the cylinder body 2 and the inner bottom wall of the mounting cavity 101 to facilitate the installation of the air supply pipeline 6.

[0024] like Figure 1As shown, the piston 3 includes a bearing plate 31 and a piston cylinder 32 which are fixedly connected. The bearing plate 31 is sealed and fixed to the top of the piston cylinder 32. In this embodiment, the bearing plate 31 and the piston cylinder 32 are integrally arranged. The piston cylinder 32 is sleeved on the outer wall of the cylinder body 2 and is airtightly connected to the cylinder body 2. The air source is connected to the hollow chamber 21 of the cylinder body 2 through the air supply pipeline 6 and drives the piston 3 to move in the vertical direction. Specifically, in this embodiment, an air supply channel 5 is provided on the support seat 1. The air supply pipeline 6 is arranged in the gap between the bottom end of the cylinder body 2 and the inner bottom wall of the installation cavity 101. One end of the air supply pipeline 6 is connected to the air supply channel 5, and the other end is connected to the inside of the cylinder body 2. The inside of the cylinder body 2 is a hollow chamber 21. The air source can deliver high-pressure gas (0.3-0.8MPa) to the hollow chamber 21 through the air supply channel 5 and the air supply pipeline 6 to drive the piston 3 to move in the vertical direction to achieve the air floating bearing effect.

[0025] The specific method of airtight connection is: Figure 1 , 3 As shown, an airbag ring 11 is arranged between the piston 3 and the outer wall of the cylinder body 2. The airbag ring 11 is made of rubber or polyurethane. Since the traditional rubber sealing ring cannot dynamically adjust the pressure, the airbag ring 11 is used in this embodiment to control the support stiffness by the inflation amount. The structure of the airbag ring 11 is the prior art. The airbag ring 11 is sleeved on the outer periphery of the cylinder body 2. The upper edge of the airbag ring 11 is fixedly connected to the piston cylinder 32 through the upper pressure ring 12, and the lower edge of the airbag ring 11 is fixedly connected to the cylinder body 2 through the lower pressure plate 13. The longitudinal section of the upper pressure ring 12 is L-shaped, and an annular groove is provided on the piston cylinder 32, and the upper pressure ring 12 is engaged in the annular groove; the upper end of the airbag ring 11 is sealed and fixedly connected to the upper pressure ring 12, and the contact surface between the upper pressure ring 12 and the airbag ring 11 is coated with silicone grease lubricant to reduce friction and wear. The lower pressure plate 13 is an annular flat plate structure, which is fixed to the mounting ring 9 by screws. The lower end of the airbag ring 11 is sealed and fixedly connected to the lower pressure plate 13. The contact surface between the lower pressure plate 13 and the airbag ring 11 is provided with a buffer gasket with a thickness of 1 mm made of fluororubber for absorbing vibration impact. The buffer gasket is not shown in the figure.

[0026] The airbag ring 11 is used to form an annular sealing cavity, which has both supporting and sealing functions. When air is supplied to the hollow chamber 21 in the cylinder body 2, the piston 3 is suspended, which satisfies the lifting effect of the generator set 17 placed on the bearing plate 31. When the piston 3 is suspended, the airbag ring 11 can reduce the vertical stiffness to the greatest extent, so that the generator set 17 on the bearing plate 31 is in a state of approximately unconstrained freedom, thereby improving the accuracy of the modal test results.

[0027] In order to satisfy the excitation force application, such as Figure 1As shown, an exciting motor 4 is provided between the load-bearing plate 31 and the supporting seat 1. In this embodiment, the exciting motor 4 adopts an existing linear motor. Of course, any other structure can also be selected, such as the combination of a rotary motor and a crank slider mechanism, which can also convert the rotary motion into a linear reciprocating motion to achieve excitation. The exciting motor 4 includes a coaxially arranged stator part 42 and a mover part 41. The mover part 41 is connected to the load-bearing plate 31 through a flange, and outputs an axial exciting force to drive the load-bearing plate 31 to perform vertical reciprocating vibration along the vertical direction. The stator part 42 is fixedly mounted on the supporting seat 1 and coaxially sleeved on the outer periphery of the mover part 41. Specifically, a first annular support plate 7 is fixedly provided on the supporting seat 1, and the stator part 42 is fixedly mounted on the first support plate 7 through a second support plate 8. As shown Figure 1 , 2 As shown, in this embodiment, a plurality of excitation motors 4 are provided, which are arranged at intervals along the circumference of the first support plate 7, and each excitation motor 4 is fixed to the first support plate 7 through the second support plate 8. The stator part 42 contains an electromagnetic coil, which generates an alternating magnetic field after being energized, and the mover part 41 moves vertically under the action of the magnetic field to transmit the excitation force. In this embodiment, the excitation range of the excitation motor 4 is 0.1 to 10KN, and the frequency response is 0.1 to 200Hz, covering the main vibration modes of the generator set.

[0028] Furthermore, in order to reduce frictional resistance, Figure 1 As shown, at least one row of vertical mounting grooves 19 is provided on the outer wall of the cylinder body 2. In this embodiment, two rows of vertical mounting grooves 19 are provided, and the two rows of vertical mounting grooves 19 are arranged at intervals along the axial direction (i.e., the vertical direction) of the cylinder body 2. Each row of vertical mounting grooves 19 includes a plurality of vertical mounting grooves 19 arranged at intervals along the circumferential direction of the outer wall of the cylinder body 2, such as Figure 2 As shown, in this embodiment, each row of vertical installation slots 19 includes eight vertical installation slots 19. Figure 1 As shown, a plurality of rolling bodies are uniformly embedded in each vertical mounting groove 19, where the rolling bodies refer to balls 10, which are similar to the structure of bearings. In this embodiment, four balls 10 are embedded in each vertical mounting groove 19, that is, a total of 32 balls 10 are embedded in each row of vertical mounting grooves 19, and a total of 64 balls 10 are embedded in two rows of vertical mounting grooves 19. The number of vertical mounting grooves 19 and the number of balls 10 can be adjusted according to actual applications. A plurality of balls 10 are rotatably fixed in the vertical mounting grooves 19 by ball retainers. Since the structure and fixing method of the ball retainer and the connection relationship between the balls 10 and the ball retainer are prior art, they are not described in detail in this embodiment. The balls 10 are exposed in the vertical mounting grooves 19 and are in rolling contact with the inner wall of the piston cylinder 32. When the load-bearing plate 31 is driven by high-pressure gas to move in air floating or is excited at a high frequency by the exciting motor 4, the ball 10 rolls back and forth rapidly, converting the sliding friction between the piston 3 and the cylinder body 2 into rolling friction, and the friction resistance is reduced to below 5N.

[0029] When this embodiment is used, Figure 1 , 4 As shown, an air source is used to supply air to the hollow chamber 21 of the cylinder 2 through the air supply channel 5 and the air supply pipeline 6, and the piston 3 is suspended to lift the generator set 17 placed on the load-bearing plate 31 to meet the support height. Then, the exciting motor 4 is used to apply an exciting force to the generator set 17, and a modal test is performed on the generator set 17. The device integrates the air floating support and the exciting force function into one device, which reduces the volume of the device by 40%, simplifies the device structure, achieves the dual effects of support and exciting force application, and reduces the installation and commissioning time from 4 hours to 30 minutes, reducing the preparation work before the test and the operating procedures during the test, making it more convenient, and improving the test accuracy and efficiency. If a large generator set 17 is to be supported and tested, it is only necessary to increase the number of this embodiment so that multiple load-bearing plates 31 can jointly support a large generator set 17, see Figure 4 .

[0030] This embodiment has the advantages of large load-bearing capacity, low stiffness, and high excitation frequency. It combines air-floating bearing technology with electromagnetic excitation technology. The device itself has load-bearing capacity, eliminating the tediousness caused by the additional setting of supporting devices. The air-floating bearing technology makes the generator set 17 in a state of near free and unconstrained, saving a lot of material and labor costs. The excitation motor 4 provides the excitation force, and the excitation force transmission efficiency is increased to 98% (traditional equipment ≤ 85%), which helps to improve the accuracy of the modal test results, effectively shorten the test cycle, improve the test efficiency, and ensure the accuracy of the modal test of the generator set, so as to determine whether the subsequent generator set 17 can be used normally.

[0031] A second exemplary embodiment of the present invention provides an automated control system for automatically controlling the first exemplary embodiment, such as Figure 1 , 5 As shown, this embodiment includes a controller and a proportional control valve 14. The controller, the proportional control valve 14 and the connection between the two are all prior art. The controller is not shown in the figure. The controller is installed on the outer wall of the support seat 1 or in an independent control box and is close to the proportional control valve 14 to reduce the signal transmission distance. In this embodiment, the proportional control valve 14 is fixed on the first support plate 7 of the support seat 1. The outlet end of the proportional control valve 14 is connected to the air supply pipeline 6 to adjust the gas flow and pressure of the air supply pipeline 6. The control accuracy in this embodiment is ±0.05MPa. Figure 1As shown, the first support plate 7 is also provided with an air supply channel 5, which is connected to the air supply channel 5 on the support seat 1, and the outlet end of the proportional control valve 14 is also connected to the air supply channel 5 of the first support plate 7 through the air supply pipeline 6. The proportional control valve 14 is electrically connected to the controller to receive control instructions to automatically adjust the intake pressure. Working principle: The floating height of the piston 3 is set according to the support height requirement, and the controller sends a control instruction to the proportional control valve 14, so that the high-pressure gas is sent to the cylinder 2 through the air supply channel 5 and the air supply pipeline 6, thereby pushing the piston 3 to move up to the set height.

[0032] In order to monitor the suspension height of the load-bearing plate 31, the present embodiment further includes a displacement sensor 15 and a sensing plate 16, both of which are prior art. Figure 1 As shown, the induction plate 16 is fixed on the side of the bearing plate 31 facing the support seat 1 (i.e., the bottom surface of the bearing plate 31), and the displacement sensor 15 is fixed on the support seat 1 at a position corresponding to the induction plate 16. In this embodiment, an L-shaped support plate 20 is fixed on the first support plate 7, and the displacement sensor 15 is fixed on the support plate 20. The displacement sensor 15 is electrically connected to the controller, and the displacement sensor 15 monitors the displacement of the piston 3 (i.e., the suspension height) in real time and feeds back to the controller. The working principle is as follows: Figure 5 As shown, the displacement sensor 15 monitors the displacement of the load-bearing plate 31 in real time, and transmits the displacement signal to the controller for the controller to determine the support height of the piston 3. If the displacement is caused by the change in the weight of the generator set 17, the displacement sensor 15 will feedback to the controller, and the controller will adjust the proportional control valve 14 to increase or decrease the air supply, thereby adjusting the support height of the generator set 17, maintaining the constant suspension height of the load-bearing plate 31, achieving a precise load-bearing effect, and facilitating improving the accuracy of the test.

[0033] like Figure 1 As shown, this embodiment also includes a pressure sensor 18 disposed between the excitation motor 4 and the support seat 1. The pressure sensor 18 adopts the existing technology. In this embodiment, the pressure sensor 18 is disposed between the first support plate 7 and the second support plate 8. The pressure sensor 18 is electrically connected to the controller to transmit pressure parameters. The controller is electrically connected to the excitation motor 4. The controller can send an excitation instruction to the excitation motor 4. The excitation motor 4 applies a sinusoidal excitation of a specified peak force to the generator set 17 through the piston 3 in the form of a fixed frequency or a swept frequency. The working principle is as follows: Figure 5 As shown, the pressure sensor 18 feeds back the flotation pressure parameters to the controller. The controller determines whether it is necessary to adjust the frequency and amplitude of the alternating current of the vibration motor 4 according to a preset program and sends a vibration instruction to the vibration motor 4, thereby controlling the vibration motor 4 to apply a target vibration force to the generator set 17 to ensure the accuracy of the applied vibration force.

[0034] In general, the controller in this embodiment has two functions: one is to adjust the air floating height of the piston 3: according to the feedback of the displacement sensor 15, the opening of the proportional control valve 14 is dynamically adjusted to maintain the set floating height. The other is to control the exciting force: by adjusting the current of the exciting motor 4, the magnitude and frequency of the output force of the mover part 41 are controlled.

[0035] A third exemplary embodiment of the present invention provides an automated control method, which employs the second exemplary embodiment, such as Figure 6 As shown, the specific steps include: S1. Setting the flotation pressure; The required flotation pressure is calculated according to the weight of the generator set 17, and the initial value is set by the controller; in this embodiment, the weight of the generator set 17 is 50 tons, and the required flotation pressure is 0.5MPa.

[0036] S2. Input the exciting force parameters; input the target exciting force and frequency, and the controller automatically matches the exciting motor current; in this embodiment, the target exciting force is 5KN, the frequency is 50Hz, and the exciting motor current is 20A.

[0037] S3. Turn on the gas source and controller, and the piston 3 is suspended to the set height of 50 mm.

[0038] S4. Vibration test; the controller sends an instruction, and the vibration motor 4 applies the target vibration force at the input frequency for a certain period of time; in this embodiment, the vibration motor 4 applies 5KN vibration force at a frequency of 50Hz for 10 seconds.

[0039] S5. Data acquisition; recording the vibration signal of the generator set 17 through the acceleration sensor, analyzing the modal parameters such as the natural frequency and damping ratio; S6. Automatic adjustment: If the air flotation pressure fluctuation exceeds the limit (such as exceeding ±0.1MPa) during the test, the controller dynamically adjusts the opening of the proportional control valve 14 to maintain the air flotation pressure stable.

[0040] This step also includes an intelligent adjustment phase, which includes the following: Dynamic balance; the displacement sensor 15 monitors the height of the piston 3 in real time. If a deviation is detected, the controller adjusts the proportional control valve 14 to increase or decrease the air supply to maintain a constant suspension height; Closed-loop control of the exciting force; the pressure sensor 18 monitors the fluctuation of the air flotation pressure, and the controller synchronously adjusts the output force of the exciting motor 4 to ensure that the amplitude of the exciting force is stable (ie, the fluctuation is ≤±2%).

[0041] S7. Output the test results.

[0042] The modal frequency detection error obtained by the above embodiment is ≤0.1 Hz (conventional method is ≥0.5 Hz); and under 5 Hz to 200 Hz wide-band excitation, the air floating height fluctuation is ≤±0.05 mm, so the anti-interference ability is strong.

[0043] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A large-scale generator set modal test detection device, characterized in that: It includes a supporting seat, a cylinder body, an air source, a piston, an exciting motor and a load-bearing plate; the cylinder body is fixedly mounted on the supporting seat, the interior of the cylinder body is a hollow chamber, the piston includes a load-bearing plate and a piston cylinder that are fixedly connected, the piston cylinder is sleeved on the outer wall of the cylinder body and is airtightly connected to the cylinder body, the air source is connected to the hollow chamber of the cylinder body through an air supply pipeline and drives the piston to move in a vertical direction, the load-bearing plate is sealed and fixed to the top of the piston cylinder, the exciting motor is arranged between the load-bearing plate and the supporting seat, the exciting motor includes a stator part and a mover part that are coaxially arranged, the mover part is fixedly connected to the load-bearing plate and outputs an axial exciting force to drive the load-bearing plate to reciprocate vertically, and the stator part is fixedly mounted on the supporting seat and coaxially sleeved on the outer periphery of the mover part.

2. The large generator set modal test detection device according to claim 1 is characterized in that: An airbag ring is arranged between the piston and the outer wall of the cylinder body. The airbag ring is sleeved on the periphery of the cylinder body. The upper edge of the airbag ring is fixedly connected to the piston through an upper pressure ring, and the lower edge of the airbag ring is fixedly connected to the cylinder body through a lower pressure plate.

3. The large generator set modal test detection device according to claim 2, characterized in that: The excitation motor is a linear motor.

4. The large generator set modal test detection device according to any one of claims 1 to 3, characterized in that: At least one row of vertical mounting grooves is arranged on the outer wall of the cylinder body, and each row of vertical mounting grooves includes a plurality of vertical mounting grooves arranged at intervals along the circumference of the outer wall of the cylinder body, and a plurality of rolling bodies are evenly embedded in each vertical mounting groove. The rolling bodies are exposed in the vertical mounting grooves and in rolling contact with the inner wall of the piston.

5. The large generator set modal test detection device according to claim 4, characterized in that: The supporting seat is made of high-strength aluminum alloy material.

6. An automatic control system for automatically controlling the large generator set modal test detection device according to any one of claims 1 to 5, characterized in that: It includes a controller and a proportional control valve; the proportional control valve is fixed on a supporting seat and electrically connected to the controller, and the outlet end of the proportional control valve is connected to an air supply pipeline.

7. The automatic control system according to claim 6, characterized in that: It also includes a displacement sensor and a sensing plate. The sensing plate is fixed on the side of the load-bearing plate facing the supporting seat. The displacement sensor is fixed on the supporting seat at a position corresponding to the sensing plate. The displacement sensor is electrically connected to the controller. The displacement sensor monitors the piston displacement in real time and feeds back to the controller.

8. The automatic control system according to claim 7, characterized in that: It also includes a pressure sensor arranged between the excitation motor and the supporting seat. The pressure sensor is electrically connected to the controller to transmit pressure parameters. The controller is electrically connected to the excitation motor.

9. An automated control method, using the automated control system according to any one of claims 6 to 8, characterized in that: The method comprises the following steps: S1. Setting of air flotation pressure: Calculate the required air flotation pressure according to the weight of the generator set and set the initial value through the controller; S2. Input the excitation force parameters; input the target excitation force and frequency, and the controller automatically matches the excitation motor current; S3. Turn on the gas source and controller, and the piston will float to the set height; S4. Vibration test: the controller sends a command, and the vibration motor applies the target vibration force at the input frequency for a certain period of time; S5. Data acquisition: record the vibration signal of the generator set through the acceleration sensor and analyze its modal parameters; S6. Automatic adjustment: If the air flotation pressure fluctuation exceeds the limit during the test, the controller dynamically adjusts the opening of the proportional control valve to maintain the air flotation pressure stable; S7. Output the test results.

10. The automatic control method according to claim 9, characterized in that: Step S6 also includes an intelligent adjustment stage, which includes the following contents: Dynamic balance; the displacement sensor monitors the piston height in real time. If a deviation is detected, the controller adjusts the proportional control valve to increase or decrease the air supply to maintain a constant suspension height; Closed-loop control of the exciting force; the pressure sensor monitors the fluctuation of the air flotation pressure, and the controller synchronously adjusts the output force of the exciting motor to ensure the stability of the exciting force amplitude.

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