Dynamic stress test system
By replacing the slip ring structure with strain gauges and telemetry devices in the generator, wireless transmission of dynamic stress testing was achieved, solving the problem of high stability of rotating parts caused by the slip ring structure and ensuring the accuracy and reliability of the test.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DONGFANG ELECTRIC MACHINERY
- Filing Date
- 2025-05-22
- Publication Date
- 2026-05-12
AI Technical Summary
In the prior art, the retaining ring outside the generator rotor bar needs to be tested for dynamic stress, but the slip ring structure has high requirements for the stability of rotating parts, making it difficult to guarantee the stability of the test piece.
By replacing the slip ring structure with strain gauges and telemetry devices, the strain gauges are installed on the test piece and the telemetry devices are installed on the rotating parts, enabling wireless transmission of electrical signals and reducing the stability requirements of the test piece.
This method enables dynamic stress testing of retaining rings under rotating conditions, reducing the stability requirements of the test environment for the test piece and ensuring the accuracy and reliability of the test data.
Smart Images
Figure CN224231130U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of testing technology, and in particular to a dynamic stress testing system. Background Technology
[0002] In related technologies, retaining rings are required to surround the rotor bars of generators to prevent insulation damage caused by large deformation of the rotor bars due to centrifugal force. Since the retaining ring rotates with the rotor windings, dynamic stress testing is necessary to ensure it meets usage requirements and to verify simulation results and allow engineers to optimize technical solutions. However, currently, slip ring structures are typically used for dynamic stress testing of rotating components. Slip ring structures consist of stationary and moving parts, which are fixed to the stationary and rotor structures, respectively. The test piece cannot have large axial or radial displacements, and high stability is required. Utility Model Content
[0003] This application provides a dynamic stress testing system that eliminates the use of a slip ring structure, thereby reducing the stability requirements of the test piece and at least partially solving the aforementioned technical problems.
[0004] To achieve the above objectives, according to a first aspect of this application, a dynamic stress testing system is provided for use in a generator, the generator including a rotating component and a test piece, the rotating component rotating synchronously with the test piece, the dynamic stress testing system comprising:
[0005] Strain gauges are configured to be mounted on the test specimen;
[0006] A telemetry device is configured to be installed on the rotating component, the telemetry device being electrically connected to the strain gauge, for receiving the voltage signal fed back by the strain gauge, and converting the voltage signal into a wireless communication signal;
[0007] The terminal is wirelessly connected to the telemetry device to receive the wireless communication signal and convert the wireless communication signal into dynamic stress parameters.
[0008] Optionally, the telemetry device is spaced apart from the test piece along the axial direction of the rotating component.
[0009] Optionally, at least two strain gauges are provided, and the at least two strain gauges are spaced apart along the axial direction of the test piece.
[0010] Optionally, at least two strain gauges arranged along the axial direction of the test piece form a strain gauge group, wherein the strain gauge group is configured to be at least two, and the at least two strain gauge groups are arranged at circumferential intervals along the test piece.
[0011] Optionally, the telemetry device has at least two signal channels, each of which is electrically connected to a strain gauge, wherein each of the signal channels synchronously transmits an electrical signal.
[0012] Optionally, at least two telemetry devices are provided, and the at least two telemetry devices are arranged symmetrically on the outer peripheral surface of the rotating component.
[0013] Optionally, the terminal includes:
[0014] A signal receiver is wirelessly connected to the telemetry device.
[0015] The signal processor is electrically connected to the signal receiver.
[0016] Optionally, the signal receiver is a WIFI signal receiver.
[0017] Optionally, the telemetry device includes a full-bridge test module, a half-bridge test module, and a 1 / 4-bridge test module; or
[0018] The telemetry device has a bridging module, which integrates a full-bridge test unit, a half-bridge test unit, and a 1 / 4-bridge test unit.
[0019] Optionally, the test piece is a retaining ring, the generator includes a rotor winding, the rotor winding has a plurality of rods distributed circumferentially, the retaining ring is sleeved on the rods, and the strain gauge is disposed on the outer surface of the retaining ring.
[0020] In the dynamic stress testing system of this application embodiment, a strain gauge is installed on the test piece, and a telemetry device is installed on the rotating part. The strain gauge transmits the measured electrical signal to the telemetry device, and the telemetry device wirelessly transmits the signal to the terminal, thus realizing dynamic stress testing. In this application embodiment, the original slip ring structure is replaced by the cooperation of the strain gauge and the telemetry device. Since both the strain gauge and the telemetry device are installed on the rotating part, the requirements of the test environment for the test piece can be reduced.
[0021] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.
[0024] Figure 1 This is a schematic diagram of the dynamic stress testing system provided in an exemplary embodiment of this application;
[0025] Figure 2 This is one of the structural block diagrams of the telemetry device provided in the exemplary embodiments of this application;
[0026] Figure 3 This is a second structural block diagram of the telemetry device provided in the exemplary embodiments of this application.
[0027] Explanation of reference numerals in the attached figures:
[0028] 1. Strain gauge; 11. Strain gauge assembly;
[0029] 2. Telemetry device; 21. Full-bridge test module; 22. Half-bridge test module; 23. 1 / 4-bridge test module; 24. Bridging module; 241. Full-bridge test unit; 242. Half-bridge test unit; 243. 1 / 4-bridge test unit;
[0030] 3. Terminal; 31. Signal receiver; 32. Signal processor;
[0031] 4. Rotating parts;
[0032] 5. Test piece. Detailed Implementation
[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.
[0034] Reference Figures 1 to 3 This application provides a dynamic stress testing system. The dynamic stress testing system is applied to a generator. The generator includes a rotating component 4 and a test piece 5. The rotating component 4 rotates synchronously with the test piece 5. The dynamic stress testing system includes a strain gauge 1, a telemetry device 2, and a terminal 3. The strain gauge 1 is configured to be mounted on the test piece 5. The telemetry device 2 is configured to be mounted on the rotating component 4 and is electrically connected to the strain gauge 1. The telemetry device 2 receives the voltage signal fed back by the strain gauge 1 and converts the voltage signal into a wireless communication signal. The terminal 3 is wirelessly connected to the telemetry device 2 and receives the wireless communication signal, converting the wireless communication signal into dynamic stress parameters.
[0035] In this embodiment, by installing strain gauge 1 on the test piece 5 and telemetry device 2 on the rotating part 4, strain gauge 1 transmits the measured electrical signal to telemetry device 2, which then wirelessly transmits the signal to terminal 3, thus achieving dynamic stress testing. This embodiment replaces the original slip ring structure with the cooperation of strain gauge 1 and telemetry device 2. Since both strain gauge 1 and telemetry device 2 are installed on the rotating part, the requirements for the testing environment of the test piece 5 can be reduced.
[0036] In some embodiments, finite element simulation analysis can be performed on the test piece 5 first to determine the dynamic stress distribution on the outer surface of the test piece 5, locate the dynamic stress sensitive areas of the test piece 5, and determine the locations of dynamic stress measurement points based on the structure of the test piece 5, recording the simulated dynamic stress values at the measurement points under different working conditions. Then, a strain gauge 1 is set at each measurement point to achieve targeted measurement. Thus, by determining the dynamic stress sensitive areas of the test piece 5 through finite element simulation, and then determining the measurement points based on these sensitive areas, the selection of measurement points is more scientific and reasonable, and the dynamic stress sensitivity of the measurement point locations is high, which is beneficial for obtaining accurate experimental data.
[0037] In some embodiments, wireless communication signals include WIFI signals, electromagnetic wave signals, etc.
[0038] In some embodiments, the generator has a drive mechanism, which may be a water turbine or the like. The drive mechanism can drive the rotating component 4 and the test component 5 to rotate synchronously.
[0039] In some embodiments, strain gauge 1 is a resistive strain gauge 1. When the test piece 5 deforms and presses against strain gauge 1, the strain gauge 1 deforms accordingly, causing a change in its own resistance. This change in resistance of strain gauge 1 causes a change in the voltage fed back to telemetry device 2. After this voltage signal is sent to telemetry device 2, telemetry device 2 can convert the electrical signal and wirelessly transmit it to terminal 3. After receiving the wireless signal, terminal 3 converts and calculates the signal to obtain the dynamic stress parameters at the corresponding position of the test piece 5.
[0040] In some embodiments, strain gauge 1 is bonded to the outer surface of the test piece 5. Before bonding, strain gauge 1 needs to be surface-polished and cleaned. To ensure reliable bonding of strain gauge 1 and prevent separation of strain gauge 1 from the test piece 5 under high-speed rotor rotation, strain gauge 1 is bonded to the outer surface of the test piece 5 using strong adhesive or metal repair agent.
[0041] In some embodiments, the telemetry device 2 and the strain gauge 1 are electrically connected via wires. The wires are bonded to the outer surface of the test piece 5 and / or the rotating part 4.
[0042] like Figure 1As shown, in some embodiments, the telemetry device 2 and the test piece 5 are spaced apart along the axial direction of the rotating member 4.
[0043] It is understood that the rotating component 4 is the generator's shaft, and the test piece 5 is the retaining ring of the generator rotor winding. Since the telemetry device 2 is located on the test piece 5, and the strain gauge 1 is located on the rotating component 4, the telemetry device 2 and the test piece 5 are spaced apart to avoid interference with other components positioned between them.
[0044] In some embodiments, the distance between the telemetry device 2 and the test piece 5 can be specifically selected according to the generator model. For example, when applied to a small generator, the distance between the telemetry device 2 and the test piece 5 can be set to 5 mm. When applied to a large generator, the distance between the telemetry device 2 and the test piece 5 can be set to 50 mm.
[0045] It should be noted that, in order to reduce the centrifugal force on the conductor, the distance between the telemetry device 2 and the test piece 5 should not be too large, thus keeping the conductor length short. This not only reduces conductor material consumption and cost but also prevents the conductor from detaching due to centrifugal force.
[0046] like Figure 1 As shown, in some embodiments, at least two strain gauges 1 are provided. The at least two strain gauges 1 are arranged at intervals along the axial direction of the test specimen 5.
[0047] Understandably, by setting multiple strain gauges 1, dynamic stress parameter analysis can be performed at multiple axial positions of the test piece 5, ensuring the accuracy and effectiveness of data acquisition.
[0048] For example, two strain gauges 1 are arranged at axial intervals along the test piece 5.
[0049] Please continue reading. Figure 1 In some embodiments, at least two strain gauges 1 arranged along the axial direction of the test piece 5 form a strain gauge group 11. The strain gauge group 11 is configured to be at least two, and the at least two strain gauge groups 11 are arranged at circumferential intervals along the test piece 5.
[0050] Understandably, by setting up multiple strain gauge groups 11, dynamic stress parameter analysis can be performed at multiple locations in the circumferential direction of the test piece 5, ensuring the accuracy and effectiveness of data acquisition.
[0051] For example, two strain gauge groups 11 are arranged at circumferential intervals along the test piece 5. The two strain gauge groups 11 are arranged at 90-degree intervals on the outer surface of the test piece 5.
[0052] In some embodiments, the telemetry device 2 has at least two signal channels. Each signal channel is electrically connected to a strain gauge 1. Each signal channel transmits an electrical signal synchronously.
[0053] It is understandable that by equipping the telemetry device 2 with multiple signal channels, one telemetry device 2 can be electrically connected to multiple strain gauges 1, which can reduce the number of telemetry devices 2, reduce costs, and reduce the risk of the self-rotating component 4 of the telemetry device 2 being thrown out.
[0054] For example, a telemetry device 2 may have six, eight, or twelve signal channels.
[0055] In this embodiment, a telemetry device 2 with multi-channel synchronous transmission is used to transmit data, which can effectively solve the drawback of the slip ring structure in related technologies that cannot achieve multi-channel measurement, and ensure the stability and reliability of data testing.
[0056] In some embodiments, at least two telemetry devices 2 are provided. The at least two telemetry devices 2 are arranged symmetrically on the outer peripheral surface of the rotating member 4.
[0057] Understandably, each telemetry device 2 has a limited number of signal channels. When the number of strain gauges 1 is large, at least two telemetry devices 2 need to be arranged. At least two telemetry devices 2 are arranged symmetrically on the outer circumferential surface of the rotating part 4 to ensure the stability of the rotating part 4 during rotation.
[0058] In some embodiments, at least two telemetry devices 2 can also be fastened to the outer peripheral surface of the rotating member 4 using fasteners. For example, after at least two telemetry devices 2 are installed on the outer surface of the rotating member 4, they can be fastened using wire ropes, clamps, or the like. Alternatively, a locking mechanism can be used to reliably fix at least two telemetry devices 2 to the outer surface of the rotating member 4.
[0059] Please continue reading. Figure 1 In some embodiments, terminal 3 includes a signal receiver 31 and a signal processor 32. The signal receiver 31 is wirelessly connected to the telemetry device 2. The signal processor 32 is electrically connected to the signal receiver 31.
[0060] Understandably, signal receiver 31 is used to receive the wireless signal output by telemetry device 2. Signal processor 32 is used to receive the wireless signal received by signal receiver 31. Signal receiver 31 can convert the wireless signal into an electrical signal before sending it to signal processor 32. After receiving the electrical signal, signal processor 32 can calculate and convert it into dynamic stress parameters, and then display them.
[0061] In some embodiments, the signal receiver 31 is a WIFI signal receiver. Thus, a wireless signal connection between the terminal 3 and the telemetry device 2 is achieved through WIFI communication.
[0062] like Figure 2 As shown, in some embodiments, the telemetry device 2 includes a full-bridge test module 21, a half-bridge test module 22, and a quarter-bridge test module 23.
[0063] It is understandable that by setting up independent full-bridge test module 21, half-bridge test module 22 and 1 / 4-bridge test module 23 in the telemetry device 2, the telemetry device 2 can have full-bridge test capability, half-bridge test capability and 1 / 4-bridge test capability to adapt to different test scenarios.
[0064] like Figure 3 As shown, in some embodiments, the telemetry device 2 has a bridging module 24, which integrates a full-bridge test unit 241, a half-bridge test unit 242, and a quarter-bridge test unit 243.
[0065] It is understandable that by setting a bridging module 24 in the telemetry device 2, the bridging module 24 integrates a full-bridge test unit 241, a half-bridge test unit 242, and a 1 / 4-bridge test unit 243, so that the telemetry device 2 has full-bridge test capability, half-bridge test capability, and 1 / 4-bridge test capability to adapt to different test scenarios.
[0066] In some embodiments, the bridging method between the telemetry device 2 and the strain gauge 1 can be determined according to the Wheatstone bridge principle and the actual situation.
[0067] In some embodiments, the test piece 5 is a retaining ring, the generator includes a rotor winding, the rotor winding has a plurality of rods distributed circumferentially, the retaining ring is sleeved on the outside of the rods, and the strain gauge 1 is disposed on the outer surface of the retaining ring.
[0068] Understandably, strain gauge 1 is placed on the outer surface of the retaining ring to obtain the dynamic stress parameters of the outer surface of the retaining ring. Based on this dynamic stress testing system, the dynamic stress of the retaining ring structure under different working conditions can be accurately measured, further refining the simulation calculation method and providing strong support for technicians to optimize technical designs.
[0069] In some embodiments, strain gauge 1 is a right-angle strain rosette, a triaxial strain gauge 1, which can acquire strain values in three directions at each measuring point. The principal strains at each measuring point in the first and second directions can be calculated using the following formula:
[0070]
[0071] The principal stresses in the first and second directions can be calculated using the following formulas:
[0072]
[0073] The theoretical combined stress can be calculated using the following formula:
[0074]
[0075] Since the principal stress in the third direction is 0, i.e., σ3 = 0, the theoretical combined stress can be simplified to:
[0076]
[0077] Where, ε0, ε 45 and ε 90 σ represents the strain in the three directions of the strain rosette; μ represents the Poisson's ratio of the retaining ring material; E represents the elastic modulus of the retaining ring material; σ1, σ2 and σ3 represent the three principal stresses respectively; σ represents the theoretical combined stress.
[0078] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0079] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0080] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.
[0081] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.
Claims
1. A dynamic stress testing system applied to a generator, the generator comprising a rotating component (4) and a test piece (5), the rotating component (4) rotating synchronously with the test piece (5), characterized in that, The dynamic stress testing system includes: Strain gauge (1) is configured to be mounted on the test piece (5); Telemetry device (2) is configured to be installed on the rotating part (4). The telemetry device (2) is electrically connected to the strain gauge (1) and is used to receive the voltage signal fed back by the strain gauge (1) and convert the voltage signal into a wireless communication signal. The terminal (3) is wirelessly connected to the telemetry device (2) to receive the wireless communication signal and convert the wireless communication signal into dynamic stress parameters.
2. The dynamic stress testing system according to claim 1, characterized in that, Along the axial direction of the rotating component (4), the telemetry device (2) and the test piece (5) are spaced apart.
3. The dynamic stress testing system according to claim 1, characterized in that, The strain gauges (1) are configured to be at least two, and the at least two strain gauges (1) are arranged at axial intervals along the test piece (5).
4. The dynamic stress testing system according to claim 3, characterized in that, At least two strain gauges (1) arranged along the axial direction of the test piece (5) form a strain gauge group (11), the strain gauge group (11) is set to at least two, and the at least two strain gauge groups (11) are arranged at circumferential intervals along the test piece (5).
5. The dynamic stress testing system according to claim 3, characterized in that, The telemetry device (2) has at least two signal channels, each of which is electrically connected to a strain gauge (1), wherein each of the signal channels synchronously transmits electrical signals.
6. The dynamic stress testing system according to claim 1, characterized in that, The telemetry device (2) is configured to be at least two, and the at least two telemetry devices (2) are arranged symmetrically on the outer peripheral surface of the rotating member (4).
7. The dynamic stress testing system according to claim 1, characterized in that, The terminal (3) includes: The signal receiver (31) is wirelessly connected to the telemetry device (2); The signal processor (32) is electrically connected to the signal receiver (31).
8. The dynamic stress testing system according to claim 7, characterized in that, The signal receiver (31) is a WIFI signal receiver.
9. The dynamic stress testing system according to claim 1, characterized in that, The telemetry device (2) includes a full-bridge test module (21), a half-bridge test module (22), and a 1 / 4-bridge test module (23); or The telemetry device (2) has a bridging module (24), which integrates a full-bridge test unit (241), a half-bridge test unit (242), and a 1 / 4-bridge test unit (243).
10. The dynamic stress testing system according to claim 1, characterized in that, The test piece (5) is a retaining ring. The generator includes a rotor winding with several circumferentially distributed rods. The retaining ring is sleeved on the outside of the rods, and the strain gauge (1) is disposed on the outer surface of the retaining ring.