Generator stator slot wedge on-line data acquisition system based on acousto-optic monitoring

Abstract

The utility model belongs to stator slot wedge detection technical field discloses a kind of generator stator slot wedge on-line data acquisition system based on acousto-optic monitoring, comprising: laser ranging module;The laser ranging module is installed in the side surface of stator lower wind deflector or is installed on the rack of stator machine pit side, for through laser acquisition stator bar end surface vibration signal;Acoustic monitoring module;The acoustic monitoring module includes fixed on the optical fiber acoustic emission sensor on the rack of stator bar end side or installs in the optical fiber acoustic emission probe of stator bar fixing block, for acquisition stator bar acoustic emission signal.The utility model is through the combination of laser ranging module and acoustic monitoring module, realize the double-mode acquisition of stator bar vibration signal and acoustic emission signal;Double-mode data complement, provide more comprehensive, reliable original data for slot wedge loosening detection, support on-line detection realization.

Description

Technical Field

[0001] This utility model belongs to the field of stator slot wedge detection technology, and specifically relates to an online data acquisition system for generator stator slot wedges based on acoustic and optical monitoring. Background Technology

[0002] The problem of stator slot wedge loosening: The stator winding of a generator consists of bar-shaped wires installed inside the core. These bars are made of insulated strands of wire that are braided and gelled before being wrapped around the main insulation. During generator operation, under the combined effects of mechanical vibration and electromagnetic force, the stator bars are at risk of loosening and shifting, which may lead to insulation wear, shorten insulation life, and increase the risk of accidents during generator operation. Stator slot wedges, along with corrugated plates and other structures, can fix the bars in the stator slots, enhancing the stability of the internal structure. However, during long-term operation, the repeated application of various influencing factors such as mechanical stress, electromagnetic force, and thermal stress leads to material aging, changes in the initial clamping force within the slots, and a decrease in tightness. Creep and wear may occur in the fasteners and bars within the slots. If slot loosening is not diagnosed and addressed in a timely manner, serious safety problems may occur, such as slot wedges loosening and detaching from the stator slot opening, or the bars being scratched by severe vibrations. At the same time, after the slot wedge loosens, it will generate severe friction with the stator. The powder formed by the friction is easy to adhere to the end of the generator winding, increasing the risk of motor corona.

[0003] Existing monitoring methods: Traditional slot wedge tightness detection involves manually tapping the slot wedges and judging their tightness based on the sound heard. This method is highly subjective and cannot retain historical data. With the development of computer and information processing technology, the principles for stator slot wedge tightness detection, both domestically and internationally, are basically the same: applying pressure or tapping the slot wedges to detect displacement and / or vibration amplitude. While the specific implementation methods differ slightly, these methods rely on electronic equipment, require a high level of operator skill, and may not have sufficient space at generator maintenance sites to use the corresponding electronic equipment. Furthermore, they require shutdown for testing, resulting in low efficiency, high maintenance costs, and low accuracy. Additionally, all of the above methods are contact measurements, which may interfere with the normal operation of the generator.

[0004] The main shortcomings of existing detection methods are as follows: Testing Location and Timing: Pressure or tapping is required to analyze vibration and sound signals from the slot wedges. However, these methods all require contact with the wedges, necessitating extensive movement of the testing equipment across the entire inner surface of the stator core. To ensure energy conversion efficiency, generators have a narrow air gap between the stator and rotor, making it difficult for testing equipment to access the space. During motor operation, the high-speed rotor rotation and any foreign objects in the air gap can cause serious accidents such as rotor rubbing. Furthermore, the stator slots contain high currents and strong magnetic fields, easily interfering with automation components. Therefore, existing testing methods can only be performed when the motor is stopped, or even after the rotor has been removed, making long-term online monitoring and fault prevention impossible.

[0005] Existing technologies for detecting stator slot wedge loosening in generators are hampered by the presence of high current and strong magnetic fields during generator operation, which hinders online monitoring. Furthermore, existing contact-based detection methods cannot perform continuous monitoring during normal unit operation and pose risks of mechanical damage and electromagnetic interference. This makes it impossible to monitor key performance parameters such as stator slot wedge tightness in real time, and to identify potential defects in a timely manner. There is a risk that severe deterioration of defects may lead to sudden failures and unplanned unit shutdowns.

[0006] It is evident that how to acquire vibration and sound signals of motor stator slot wedges online without damage is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0007] The purpose of this invention is to provide an online data acquisition system for generator stator slot wedges based on acoustic and optical monitoring, so as to solve the technical problem that the existing technology cannot realize the online acquisition of stator slot wedge vibration signals and sound signals.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: This utility model provides an online data acquisition system for generator stator slot wedges based on acoustic and optical monitoring, comprising: Laser ranging module; the laser ranging module is installed on the side of the lower wind baffle of the stator or on a frame installed on the side of the stator pit, and is used to collect vibration signals from the end surface of the stator bar by laser. Acoustic monitoring module; the acoustic monitoring module includes an optical fiber acoustic emission sensor fixed on the side frame at the end of the stator bar or an optical fiber acoustic emission probe installed in the stator bar fixing block, used to collect the acoustic emission signal of the stator bar.

[0009] A further improvement of this utility model is that the laser ranging module adopts a phase-type laser ranging device; The phase-type laser ranging device is installed on the side of the lower windshield of the stator; the phase-type laser ranging device includes an annular slide rail, a laser ranging module, and a track trolley installed on the side of the lower windshield of the stator; the laser ranging module is fixed on the annular slide rail via the track trolley; the annular slide rail integrates a power supply, which connects the track trolley and the laser ranging module to provide power to the track trolley and the laser ranging module.

[0010] A further improvement of this utility model is that the laser ranging module is a multi-laser emission ranging module.

[0011] A further improvement of this utility model is that the laser ranging module is a single laser emission ranging module.

[0012] A further improvement of this utility model is that the laser ranging module adopts a phase-type laser ranging device; The phase-type laser ranging device is installed on the frame on the side of the stator pit; the phase-type laser ranging device includes a ring slide rail, a laser ranging module and a track trolley installed on the frame on the side of the stator pit; the laser ranging module is fixed on the ring slide rail by the track trolley.

[0013] A further improvement of this utility model is that it also includes two L-shaped metal brackets; Two L-shaped metal brackets are symmetrically arranged one above the other and fixed to the side wall of the frame; Each L-shaped metal bracket is fixed with a guide rail bracket with an L-shaped cross section, and the guide rail bracket is equipped with an annular slide rail; The track trolley is mounted on a circular slide rail via a traveling mechanism.

[0014] A further improvement of this utility model is that the walking mechanism includes a chassis, a connecting frame, and a retaining frame; The chassis is connected to at least two retainers via a connecting frame; each retainer has a T-shaped notch corresponding to the annular slide rail, the T-shaped notch fits onto the annular slide rail, and a pair of support wheels are installed in the T-shaped notch, the pair of support wheels contacting the upper and lower end faces of the annular slide rail; The cage is also equipped with a drive wheel and a driven wheel; the drive wheel and the driven wheel are locked on the upper and lower sides of the annular slide rail. The drive wheel is connected to a drive motor located on the cage, which provides power for the trolley to move along the annular slide rail.

[0015] A further improvement of this utility model is that an adjustable gimbal is provided on the chassis, and a laser ranging module is installed on the adjustable gimbal.

[0016] A further improvement of this utility model is that a 3mm thick nitrile rubber pad is attached to the contact surface between the L-shaped metal bracket and the frame; a metal-rubber composite shock absorption module is provided between the L-shaped metal bracket and the guide rail bracket; the metal-rubber composite shock absorption module adopts a three-layer structure of metal-rubber-metal.

[0017] A further improvement of this utility model is that: the two guide rail supports are connected by a U-shaped guide groove; the U-shaped guide groove is a non-closed loop structure; the laser ranging module and the track trolley are connected by a drag chain for transmitting signals and providing power; the drag chain is set in the U-shaped guide groove, and the inner wall of the U-shaped guide groove is fully covered with a polytetrafluoroethylene lubricating film.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention provides an online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring, comprising: a laser ranging module; the laser ranging module is installed on the side of the stator lower wind baffle or on a frame installed on the side of the stator pit, used to acquire vibration signals from the end surfaces of the stator bars via laser; and an acoustic monitoring module; the acoustic monitoring module includes a fiber optic acoustic emission sensor fixed on the frame beside the end of the bar or a fiber optic acoustic emission probe installed in the stator bar fixing block, used to acquire acoustic emission signals from the stator bars. This invention achieves dual-mode acquisition of stator bar vibration and acoustic emission signals through the combination of the laser ranging module and the acoustic monitoring module; the laser ranging module acquires vibration data non-contactly, avoiding interference with generator operation; the fiber optic acoustic emission sensor or fiber optic acoustic emission probe has strong anti-electromagnetic interference capability and is suitable for generator strong magnetic field environments. The complementary dual-mode data provides more comprehensive and reliable raw data for slot wedge loosening detection, supporting online detection.

[0019] Furthermore, this invention employs a phase-type laser ranging device, relying on the phase detection principle to achieve micron-level measurement accuracy, precisely capturing subtle changes in the radial vibration of the stator bars. The combination of the annular slide rail and the track trolley allows the laser ranging module to move along the slide rail, enabling slot-by-slot scanning monitoring of multiple stator bars, eliminating the need for repeated sensor deployment and reducing equipment costs.

[0020] Furthermore, in this invention, the laser ranging module employs a multi-laser emission ranging module, capable of simultaneously emitting multiple lasers to achieve synchronous acquisition of vibration signals from the ends of multiple stator bars. Compared to sequential measurement with a single laser, this significantly improves data acquisition efficiency, shortens the monitoring cycle, and more quickly reflects the overall state of the generator stator slot wedges. Multi-point synchronous monitoring reduces the impact of operating condition fluctuations on measurement results, enhances data consistency and comparability, and provides a more efficient data source for subsequent fusion analysis.

[0021] Furthermore, this invention employs a single-laser emission ranging module, which features a simple structure and low cost, making it suitable for applications with a small number of generator stator bars or where monitoring efficiency requirements are not high. The single laser focuses on a single measurement point, concentrating energy and enhancing anti-interference capabilities, enabling precise capture of vibration details of specific bars, making it particularly suitable for scenarios requiring focused monitoring of easily loosened areas. The module is also smaller, offering greater installation flexibility and allowing for convenient deployment within the confined space inside the generator, reducing installation difficulty.

[0022] Furthermore, this invention mounts the phase-type laser ranging device on a frame on the side of the stator pit, away from the end area of ​​the stator bars, reducing the impact of environmental factors on measurement accuracy and extending the equipment's service life. The structural design of the circular slide rail and track trolley also supports the circular movement of the laser ranging module, achieving full-range coverage monitoring. The frame mounting method does not require modification of the generator's original windshield structure, adapting to more generator models and improving the system's versatility and compatibility.

[0023] Furthermore, this invention uses two symmetrically arranged L-shaped metal brackets to fix the guide rail bracket, forming a stable installation structure that ensures the flatness and firmness of the annular slide rail and avoids measurement deviations caused by frame vibration. The combined design of the L-shaped brackets and the guide rail brackets allows for flexible adjustment of the track height and angle, ensuring that the laser beam is accurately aligned with the stator bar measurement surface. The track trolley is mounted on the annular slide rail via a traveling mechanism, ensuring smooth movement, reducing jamming, guaranteeing the continuity and stability of the monitoring process, and improving the integrity of data acquisition.

[0024] Furthermore, in this invention, the T-shaped notch of the traveling mechanism cooperates with the support wheel to achieve a stable connection between the track trolley and the annular slide rail. Simultaneously, the support wheel contacts the upper and lower surfaces of the rail, distributing the force and reducing frictional loss during movement. The driving and driven wheels are secured on the upper and lower sides of the rail, working in conjunction with the drive motor to provide power, ensuring the trolley moves smoothly and accurately along the rail, preventing deviation or derailment. The multi-cage design further improves the fit between the trolley and the rail, enhances the mechanism's vibration resistance, adapts to the mechanical vibration environment during generator operation, and ensures the accuracy of measurement positions.

[0025] Furthermore, the adjustable gimbal on the chassis of this invention can flexibly adjust the angle and height of the laser ranging module, facilitating precise alignment with the stator bar measuring surface and solving the alignment deviation problem between the track and the measuring point during installation.

[0026] Furthermore, the nitrile rubber pad on the contact surface between the L-shaped metal bracket and the frame in this invention effectively absorbs vibrations transmitted by the frame, reducing the impact of vibrations on the track and measurement module, and improving measurement stability. The composite vibration damping module with a three-layer structure of metal-rubber-metal combines the rigidity of metal with the damping properties of rubber, attenuating high-frequency vibrations generated during generator operation and preventing vibration interference with the accuracy of laser ranging. This dual vibration damping design significantly reduces the impact of environmental vibrations on the measurement system, ensuring that the laser ranging module can still acquire accurate data in complex vibration environments, thus improving the reliability of the detection results.

[0027] Furthermore, in this invention, the U-shaped guide groove connects two guide rail brackets, providing a stable installation and movement channel for the cable chain, preventing entanglement, wear, or pulling, and ensuring the continuity of signal transmission and power supply. The non-closed-loop structure of the U-shaped guide groove adapts to the movement trajectory of the track trolley, does not affect the normal operation of the trolley, and facilitates the arrangement and maintenance of the cable chain. The polytetrafluoroethylene lubricating film on the inner wall of the guide groove reduces friction during cable chain movement, reduces wear, extends the service life of the cable chain, and ensures smooth trolley movement, avoiding impact on monitoring efficiency due to cable chain jamming, and ensuring long-term stable operation of the system. Attached Figure Description

[0028] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments and descriptions of this utility model are used to explain this utility model and do not constitute an undue limitation thereof. In the drawings: Figure 1 A flowchart illustrating an online detection method for generator stator slot wedges based on acoustic-optical monitoring fusion, provided for an embodiment of this utility model; Figure 2 This is a schematic diagram of the installation of the lower windshield rail in an embodiment of this utility model; Figure 3 This is a schematic diagram of the multi-laser ranging method for the lower windshield in this embodiment of the present invention; Figure 4 This is a schematic diagram of the structure and installation of the phase-type laser ranging device in the embodiments of this utility model; Figure 5 This is a schematic diagram of the phase-type laser ranging device in the embodiments of this utility model; Figure 6 for Figure 5 Enlarged diagram of the middle circled area; Figure 7 This is a schematic diagram of the installation structure of another laser ranging device in this embodiment of the present invention; Figure 8 This is a schematic diagram of the installation method of the acoustic monitoring module in this embodiment of the present invention; Figure 9This is a schematic diagram of the installation of the fiber optic acoustic emission sensor in an embodiment of this utility model; Figure 10 This is a flowchart illustrating an online detection method for generator stator slot wedges based on acoustic-optical monitoring fusion. Figure 11 This is a schematic diagram of the structure of an autoencoder. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0030] The following detailed description is exemplary and intended to provide further detailed explanation of the present invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this invention.

[0031] Terminology Explanation: Stator slot wedge: A fixing component installed in the stator core slot of the generator to firmly fix the stator bars in the slot, preventing vibration and displacement of the bars. It is a key component to ensure the safe operation of the generator.

[0032] Phase-based laser ranging: a high-precision distance measurement technology based on the principle of laser phase detection. It calculates the target distance by high-frequency modulation of the laser and measuring the phase difference between the emitted and reflected light, and has micron-level measurement accuracy.

[0033] Acoustic emission monitoring: a non-destructive testing technology that uses high-sensitivity fiber optic acoustic emission sensors arranged at the ends of generator stator bars or in ventilation channels at the bottom of slots to collect transient elastic wave signals generated by dynamic processes such as friction, collision or minute movement between components.

[0034] Unsupervised deep learning: A machine learning method that uses only normal state data for training, without the need for manual labeling of abnormal samples. It identifies abnormal states that deviate from the normal pattern by learning the inherent rules and distribution characteristics of normal data.

[0035] Multi-condition adaptive: An intelligent mechanism that automatically adjusts detection parameters and judgment criteria according to different operating conditions of the generator (mechanical stress, thermal stress, electromagnetic force), eliminates the influence of operating condition changes on normal vibration modes, and improves the accuracy of anomaly detection.

[0036] Symmetric feature extraction: The same feature extraction method is used for sensor data of different modalities, including time-domain statistical features (root mean square value, peak factor, kurtosis) and frequency-domain distribution features (spectral centroid, spectral variance), to achieve a unified representation of the feature space.

[0037] This invention provides an online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring. It combines fiber-optic laser ranging with fiber-optic acoustic monitoring to achieve online acquisition of stator slot wedge vibration and sound signals. The acquired vibration and sound signals can be further processed to achieve online monitoring of stator slot wedge vibration. This invention addresses the technical problem that existing technologies cannot achieve online acquisition of the required monitoring data (vibration signals and / or sound signals) for stator slot wedge vibration.

[0038] If the slot wedges and corrugated plates used to secure the vertically placed stator bars become loose during normal generator operation and without any additional external force, the stator bars will vibrate radially and axially. This vibration is fundamentally different from the minor vibrations under normal operating conditions.

[0039] Under normal circumstances, the stator bars are tightly fixed within the slots of the stator core. The fixing system mainly consists of stator slots, corrugated plates, and slot wedges. The corrugated plate, a flexible insulating material, is typically placed between the bars and the slot wedges. Its main function is to provide a continuous, radial preload, pressing the bars firmly into the slots. This elastic structure compensates for dimensional changes caused by thermal expansion and contraction and dampens minor vibrations of the bars. The slot wedges, located at the stator slot openings, are the key components that ultimately lock the entire fixing system in place. They act as support components, providing preload through corrugated plate compression, securing the corrugated plates and bars and preventing them from moving radially.

[0040] Under normal generator operation, an alternating current flows through the stator bars. This current interacts with the radial magnetic field in the stator slot, generating a periodic electromagnetic force according to the law of electromagnetic induction. This electromagnetic force mainly includes: (1) Radial electromagnetic force: generated by the interaction between the bar current and the air gap magnetic field, pointing towards the bottom of the slot, with a frequency twice that of the power grid (100Hz for a 50Hz power grid). Since both the stator current and the magnetic field are power frequency alternating quantities, their multiplication produces a DC component and a harmonic component, in which the harmonic component generates a periodic excitation on the bar; (2) Harmonic electromagnetic force: generated by the high-order harmonics (such as the 5th and 7th harmonics) present in the current and magnetic field, producing electromagnetic force components of corresponding frequencies; (3) Axial electromagnetic force: generated by the interaction between the leakage magnetic field in the end region and the bar current, applying a periodic force along the bar axis. Under normal tightening conditions, the slot wedges and corrugated plates provide sufficient preload, forming a high-rigidity constraint structure and large frictional damping between the bar and the slot wall. Under this constraint, although the bar is continuously excited by periodic electromagnetic force, its vibration response is effectively suppressed within the micrometer range, exhibiting steady-state forced vibration with extremely small amplitude.

[0041] When the slot wedge and corrugated plate loosen, the preload of the fixing system decreases. Under the continuous action of the periodic electromagnetic force, the vibration mode of the bar changes from small-amplitude linear forced vibration in the tightened state to large-amplitude nonlinear forced vibration, accompanied by collision and friction effects. Radial vibration intensifies significantly, and the vibration amplitude increases. The bar, originally compressed by the preload, begins to produce obvious reciprocating motion within the radial gap under the action of the 100Hz periodic electromagnetic force, i.e., vibration. The greater the loosening, the greater the vibration amplitude. This vibration is no longer a micro-vibration, but a mechanical impact with considerable energy. It may also cause axial vibration. Due to the incomplete asymmetry of the structure, assembly differences, and the influence of radial vibration itself, a component force along the axial direction (vertical direction) of the bar will be generated. In the tightened state, this axial force is effectively limited by friction, but when radial loosening occurs, the radial vibration of the bar weakens the normal pressure between it and the slot wall, thus significantly reducing the frictional force that prevents its axial movement. Under the influence of the electromagnetic force, the bar vibrates along the axial direction.

[0042] Under normal, tightened conditions, the vibration of the bar is a steady-state forced vibration with amplitudes in the micrometer range. The time-domain signal is quasi-periodic, and the frequency-domain energy is concentrated at the 100Hz fundamental frequency and its lower harmonics (200Hz, 300Hz, etc.), exhibiting typical response characteristics of a linear system. However, in a loose state, the gap between the bar and the groove wall leads to nonlinear vibration. The bar periodically collides with the groove wall within the gap. This impact is highly nonlinear and produces two significant characteristics in the signal: pulse spikes in the time domain (each collision superimposes a steep, instantaneous high-amplitude pulse onto the stable vibration signal) and high-frequency excitation in the frequency domain (the impact theoretically excites a very wide frequency range, resulting in a large number of high-frequency components in the vibration and sound signals).

[0043] This utility model provides an online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring. It utilizes a phase-based laser ranging module to measure radial vibration at long distances and a beam-splitting interferometric laser measurement module to measure axial vibration at close distances, achieving high-precision non-contact measurement of stator bar vibration. The laser ranging module is designed with four installation methods to suit different installation environments and measurement requirements.

[0044] Please see Figure 1 As shown, this utility model embodiment provides an online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring, including a laser ranging device. The laser ranging device is a phase-type laser ranging device 2; the first installation method: the phase-type laser ranging device 2 is set on the side of the lower stator baffle 1; the phase-type laser ranging device 2 includes an annular slide rail 21, a laser ranging module 22, and a track trolley 23 installed on the side of the lower stator baffle 1; the laser ranging module 22 is fixed on the annular slide rail 21 by the track trolley 23, and the track trolley 23 measures the vibration of different slot wedges by sliding on the annular slide rail 21; the power supply integrated on the annular slide rail 21 can provide power to the track trolley 23 and the laser ranging module 22. During measurement, the light emitted by the laser ranging module 22 is modulated, and the time is indirectly measured by measuring the phase difference. The laser beam illuminates the end surface of the stator bar 3 at a suitable incident angle, and the reflected light is received by the optical receiving unit in the laser ranging module 22, thereby calculating the radial vibration of the stator bar 3. In one specific embodiment, a suitable incident angle can be 50-70°. The laser ranging module 22 is specifically model SK100, PLS-K-100, or other models.

[0045] Please see Figure 2As shown, this utility model embodiment provides an online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring, including a laser ranging device. The laser ranging device employs a multi-laser emission ranging module 20; a second installation method is a fixed phase-type laser ranging, where multiple multi-laser emission ranging modules 20 are installed on the side of the lower windshield 1, allowing simultaneous emission of multiple laser beams to measure the vibration of different stator bar ends 3. The rest is consistent with the phase-type laser ranging method. During measurement, the emitted light from the multi-laser emission ranging module 20 is modulated, and the time is indirectly measured by measuring the phase difference. Multiple laser beams emitted from the same multi-laser emission ranging module 20 irradiate the end surfaces of different stator bar 3 at appropriate incident angles. The reflected light is received by the optical receiving unit within the multi-laser emission ranging module 20, thereby calculating the radial vibration of the stator bar 3. In one specific embodiment, the appropriate incident angle can be 50-70°. The multi-laser emission ranging module 20 can be a VL53L1CB or other multi-target laser ranging modules.

[0046] Please see Figure 3 As shown, this utility model embodiment provides an online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring, including a laser ranging device. The laser ranging device is a phase-type laser ranging device 2; a third installation method: the laser ranging module 22 of the phase-type laser ranging device 2 is installed on the side of the stator pit via an annular slide rail 21 and a track trolley 23. The radial condition of different stator bars 3 is measured by sliding on the track. The annular slide rail 21 integrates a power supply to provide power to the track trolley 23 and the laser ranging module 22. During measurement, the light emitted by the laser ranging module 22 is modulated, and the time is indirectly measured by measuring the phase difference. The laser beam illuminates the end surface of the stator bar 3 at a suitable incident angle, and the reflected light is received by the optical receiving unit inside the laser ranging module 22, thereby calculating the radial vibration of the stator bar 3. In one specific embodiment, the suitable incident angle can be 50-70°. The laser ranging module 22 specifically uses models such as SK100, PLS-K-100, or other models.

[0047] In one specific implementation, please refer to Figure 4-6As shown, this utility model embodiment provides an online data acquisition system for generator stator slot wedges based on acoustic and optical monitoring, in which a phase-type laser ranging device 2 is mounted on a frame 4. Specifically, this utility model adopts a dual vibration damping design: a 3mm thick nitrile rubber pad 61 is pasted on the contact surface between the L-shaped metal bracket 60 and the frame 4 to increase friction and prevent slippage; two L-shaped metal brackets 60 are symmetrically arranged vertically and fixed on the nitrile rubber pad 61 on the side wall of the frame 4. An L-shaped guide rail bracket 210 is fixed on the L-shaped metal bracket 60, and an annular slide rail 21 is provided on the guide rail bracket 210; a prefabricated metal-rubber composite vibration damping module 62 is provided between the L-shaped metal bracket 60 and the guide rail bracket 210. The metal-rubber composite vibration damping module 62 is manufactured using a three-layer hot vulcanization bonding process of metal-rubber-metal. The middle functional layer is made of high internal damping nitrile rubber (NBR) with a Shore hardness of 65A and a thickness of 10mm. This structure utilizes the viscoelastic properties of rubber to effectively filter out mid-to-high frequency mechanical vibrations (above 100Hz) transmitted from the generator set to the guide rail, ensuring the stability of laser measurements. Simultaneously, it leverages the elastic shear deformation capability of the thick rubber layer to flexibly compensate for minute radial and circumferential displacements of the guide rail caused by thermal expansion and contraction, eliminating structural thermal stress, without mechanical slippage. The L-shaped metal bracket 60 has an elongated hole at its connection to the frame 4, replacing traditional fixed holes and allowing for radial fine-tuning during installation to compensate for ellipticity errors generated during stator frame manufacturing or installation.

[0048] The guide rail bracket 210 and the circular slide rail 21 are precision-machined from high-strength aluminum alloy profiles. The cross-section is designed as a rectangular semi-open structure, and the surface is treated with hard anodizing or chrome plating to improve wear resistance and corrosion resistance. The circular slide rail 21 is divided into several standard arc-shaped segments along its circumference, and the segments are rigidly connected by embedded dovetail connectors. The joints are precisely chamfered and ground to ensure that the flatness error of the top and side surfaces of the rail is controlled within the micrometer level, eliminating mechanical impact when the trolley passes through gaps.

[0049] In this invention, the transmission system adopts an integrated side-mounted drag chain mode, replacing the scattered sliding contact lines and independent optical fiber drag chains, thus achieving a high degree of integration of the transmission medium.

[0050] Two guide rail brackets 210 are connected by a U-shaped guide groove 211; a U-shaped guide groove 211 made of stainless steel or aluminum alloy is set between the annular guide rail bracket 210 and the frame 4. The U-shaped guide groove 211 is a non-closed loop structure with a reserved fixed end opening for cable introduction and movement of the cable chain 7. The inner wall of the U-shaped guide groove 211 is fully covered with a PTFE (polytetrafluoroethylene) lubricating film, which greatly reduces the frictional resistance of the cable chain 7 during movement and prevents the cable chain 7 from directly contacting the metal groove body to generate noise or dust. The cable chain 7 is a closed-type silent engineering plastic cable chain with high tensile strength and oil resistance. Its internal space is divided into a high-voltage area and a low-voltage area. A highly flexible and bend-resistant composite shielded cable is laid inside the cable chain 7. The cable contains two sets of independent core wires: one set is a power supply wire, directly connected to an external 24VDC regulated power supply, providing stable power to the track trolley 23 and the laser ranging module 22; the other set is a twisted-pair shielded signal wire, transmitting RS485 differential signals (A / B lines) to enable the host computer to control the start, stop, speed, and position of the track trolley 23. A stainless steel armored optical fiber is independently laid inside the cable chain 7. One end of the fiber connects to the laser ranging module 22 on the track trolley 23, and the other end passes through the fixed end of the cable chain 7 and leads to a phase analyzer outside the generator. The armor layer effectively protects the internal fiber core from compression, and the system strictly controls the bending radius of the cable chain to ≥40mm to ensure zero loss in optical signal transmission. The track trolley 23 is mounted on the annular slide rail 21 via a traveling mechanism 230.

[0051] In one specific implementation, please refer to Figure 5-6As shown, the annular slide rail 21 is a T-shaped track. The traveling mechanism 230 includes a chassis 2306, a connecting frame 2305, and a retainer 2300; the chassis 2306 is connected to at least two retainers 2300 via the connecting frame 2305; in one specific embodiment, two retainers 2300 can be provided to be connected to the upper and lower annular slide rails 21 respectively; alternatively, four retainers 2300 can be provided, two at the top and two at the bottom. A T-shaped notch is provided in the retainer 2300 corresponding to the annular slide rail 21. This T-shaped notch fits onto the annular slide rail 21, and a pair of support wheels 2303 are installed in the T-shaped notch. The pair of support wheels 2303 contact the upper and lower end faces of the annular slide rail 21, and are used to passively roll when the track trolley 23 moves, reducing friction; during installation, the retainer 2300 is inserted into the annular slide rail 21 from the side, and then the annular slide rail 21 is spliced ​​and fixed. The cage 2300 is also equipped with a drive wheel 2301 and a driven wheel 2302. The drive wheel 2301 and the driven wheel 2302 are engaged on the upper and lower sides of the annular slide rail 21. The drive wheel 2301 is connected to a drive motor 2304 located on the cage 2300, which provides power for the track trolley 23 to move along the annular slide rail 21. The chassis 2306 is equipped with an adjustment gimbal 231, on which a laser ranging module 22 is installed. The adjustment gimbal 231 is a two-dimensional fine-tuning gimbal, which uses a worm gear transmission mechanism internally to continuously fine-tune the pitch angle (-15° to +15°) and deflection angle (-20° to +20°) of the laser beam by rotating a knob. The laser ranging module 22 is covered with a stainless steel protective shell, with a light-transmitting hole on the front of the protective shell and a quartz glass window. This fully enclosed design effectively prevents oil mist and carbon dust from inside the generator from entering the optical system, ensuring the accuracy and consistency of the measurement data. The axes of the driving wheel 2301, driven wheel 2302, and support wheel 2303 are perpendicular to the axis of the annular slide rail 21.

[0052] Please see Figure 7As shown, this utility model embodiment provides an online data acquisition system for generator stator slot wedges based on acoustic and optical monitoring, including a laser ranging device; the laser ranging device adopts a beam splitting interferometric laser ranging module. The fourth installation method is an internally installed beam interferometric laser ranging module, which uses beam interferometry to measure the axial vibration of the stator slot wedge 100. The beam interferometric laser ranging module includes a beam interferometric laser displacement meter sensor head 200 (for example, a PLR3000 series fiber laser ruler) and a stator bar fixing block 400. The stator bar fixing block 400 is provided with at least two binding holes 300 and a detection hole facing the axial end of the stator slot wedge 100. The U-shaped pad 5 that fixes the end of the stator bar 3 is provided with a through hole. The beam interferometric laser displacement meter sensor head 200 is installed in the detection hole, and the laser emitting end of the beam interferometric laser displacement meter sensor head 200 faces the axial end of the stator slot wedge 100. The stator bar fixing block 400 is fixed to the U-shaped pad 5 by passing a non-woven glass ribbon through the binding hole 300 and the corresponding through hole on the U-shaped pad 5. The beam interferometric laser displacement meter sensor head 200 transmits signals via optical fiber. The optical fiber is connected to an external controller through the binding hole 300 of the stator rod end fixing block 400 and the corresponding through hole on the U-shaped pad block 5. The beam interferometric laser displacement meter sensor head 200 consists only of optical fiber and lens, without electronic components, and is not affected by electromagnetic noise. Furthermore, the sensor head structure is small: it can be controlled to be within 5 cm in length and 8 mm in diameter, avoiding interference from sensor to end vibration, and is also convenient for installation and fixation.

[0053] The phase-type laser rangefinder 2 consists of three parts: a laser emitting system, an optical receiving system, and a signal processing system. Its working principle is to measure the phase difference between the emitted light and the reflected light by high-frequency modulated laser, and then calculate the target distance and its changes.

[0054] The laser emission system includes a semiconductor laser, a laser driving circuit, an optical collimation system, and a modulation circuit. The semiconductor laser uses a 650nm red laser or a 905nm near-infrared laser diode with an output power of 1-5mW. The laser driving circuit provides constant current drive and temperature control with a temperature control accuracy of ±0.1℃. The optical collimation system consists of a collimating lens and a beam expander, which shapes the laser beam into a parallel beam with a diameter of 2-5mm and a beam divergence angle of less than 1mrad. The modulation circuit modulates the laser intensity sinusoidally or with a square wave, and the modulation frequency can be set in the range of 10-100MHz.

[0055] The optical receiving system includes a photodetector, a preamplifier circuit, a bandpass filter circuit, and a phase detection circuit. The photodetector uses an avalanche photodiode or a PIN photodiode with a response time of less than 1 ns. The preamplifier circuit has an adjustable gain range of 40-80 dB. The center frequency of the bandpass filter circuit is matched with the modulation frequency. The phase detection circuit uses a mixer or a digital phase comparator to measure the phase difference, with a phase resolution better than 0.1°.

[0056] The signal processing system includes a high-speed analog-to-digital converter (ADC), a digital signal processor (DSP) or FPGA, a communication interface module, and a power management module. The high-speed ADC has a sampling rate of ≥100 MSPS and a resolution of 12-16 bits. The DSP or FPGA executes the phase calculation algorithm to calculate the distance. The communication interface supports RS485, Ethernet, or CAN bus, with a data update rate of up to 1 kHz. The power management module supports a wide voltage input of DC24V or DC48V. Typical performance specifications for a phase-based laser ranging device are: measurement range 50-500 mm, measurement accuracy ±50 μm, resolution 10 μm, sampling frequency 1 kHz, and response time less than 1 ms.

[0057] The beam-splitting interferometric laser ranging module uses a wide-wavelength light emitted by an ultra-wide LED. Part of this light is reflected by the reference surface of the sensor head, while the portion passing through the reference surface is specularly reflected from the workpiece and returns to the sensor head. The two reflected beams interfere with each other. The intensity of the interference light at a specific wavelength is determined based on the distance between the reference surface and the workpiece. Maximum relative interference is achieved when this distance is an integer multiple of the wavelength. By using a beam splitter to separate the interference light into different wavelengths, the intensity distribution at that specific wavelength can be obtained. Waveform analysis of this distribution reveals the distance to the workpiece.

[0058] When the laser ranging module performs internal measurements, it must ensure that the laser beam is perpendicular to the surface of the slot wedge with an angle of deviation <2°. Simultaneously, the appropriate working distance must be adjusted according to the measurement range, and the probe position must be kept stable during measurement to avoid mechanical vibration interference. When using the track for measurement, a circular slide rail is used to maintain the stability of the laser ranging host. The position and angle of the laser ranging unit are adjusted according to the position of the slot wedge. The debugging process includes optical power calibration, i.e., adjusting the laser power to the optimal operating point, establishing a reference for phase measurement, and using standard gauge blocks to calibrate the distance measurement accuracy. This invention employs phase detection technology and beam splitting interferometry detection technology, achieving micron-level displacement measurement accuracy. It can capture the transient characteristics of the axial vibration of the slot wedge in real time and completely avoids the interference of traditional contact detection on generator operation, improving the safety and reliability of the detection. The optical measurement principle enables stable operation in strong electromagnetic environments, adapting to the harsh working environment of generators, while the fiber optic transmission method reduces the complexity of the system.

[0059] This utility model embodiment provides an online data acquisition system for generator stator slot wedges based on acoustic and optical monitoring, and also includes an acoustic monitoring module. Please refer to [link / reference]. Figure 8 As shown, the dashed box encloses the frame next to the stator bar end, and the protruding part is the acoustic monitoring module. The acoustic monitoring module uses a fiber optic acoustic emission sensor 500 (e.g., OptimAE), a sensor that uses fiber optic technology to detect and measure acoustic emission phenomena. Acoustic emission refers to transient elastic waves generated by changes in internal stress when a material is subjected to external forces. These waves can propagate within the material and be detected by the sensor. The fiber optic acoustic emission sensor 500 uses optical fiber as the sensing element, indirectly measuring the acoustic emission signal by measuring changes in the light signal within the fiber. It has advantages such as miniaturization, high sensitivity, and resistance to electromagnetic interference. In this example, the sensor's core performance indicators include: frequency response range of 20-450kHz, resonant frequency of 220kHz, sensitivity ≥55dB, and omnidirectional directivity. For installation, the fiber optic probe can be directly attached to the surface of the stator bar using a stator bar fixing block to achieve accurate measurement of the acoustic emission signal. Alternatively, the fiber optic probe can be installed in the ventilation groove at the bottom of the stator bar slot to achieve accurate measurement of the acoustic emission signal. To ensure signal quality, the signal acquisition system is equipped with a 100kHz sampling frequency and a 24-bit high-precision ADC, achieving a wide dynamic range of 144dB. Simultaneously, the signal is conditioned by a differential input preamplifier with 20-60dB adjustable gain to maximize the signal-to-noise ratio and suppress common-mode interference.

[0060] Please see Figure 9 As shown, this utility model embodiment provides an online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring, and also includes an acoustic monitoring module; the acoustic monitoring module uses a fiber optic acoustic emission probe 201 (e.g., OptimAE). The fiber optic acoustic emission probe 201 can be internally installed, and is fixed in the groove of the stator bar fixing block by binding with non-woven fiberglass ribbon. The probe transmits signals through an optical fiber, which is connected to an external controller through the fixing hole of the stator bar fixing block, allowing real-time acquisition of the sound signal emitted by the slot wedge loosening. Alternatively, it can be installed on a rack near the end of the stator bar, with the fiber optic probe fixed and the wiring arranged within the rack.

[0061] The acoustic monitoring module continuously acquires the acoustic emission signals of the stator bars at a sampling frequency of 100kHz. The original signal is denoted as s(n), where n is the sampling point index. The preprocessing system adopts a three-stage cascaded filtering architecture to sequentially perform background noise suppression, electromagnetic interference removal, and signal enhancement.

[0062] This utility model discloses an online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring. The acquired data can be used for online detection of generator stator slot wedges. The detection method includes feature extraction of the acquired vibration and acoustic signals; specifically including: Root Mean Square (RMS): The root mean square (RMS) value of vibration and acoustic signals reflects the effective value of the groove wedge vibration displacement and is a fundamental indicator for evaluating vibration energy. For the displacement signal x(t), the RMS value within the time window T is calculated as follows: Where N is the number of sampling points within the window, and x(n) is the amplitude of the nth sampling point. The calculation uses a sliding window method with a window length of 1 second (1000 sampling points) and a sliding step size of 100ms to ensure time resolution. Loosening of the slot wedge leads to increased vibration of the bar, increasing the amplitude x(n), and its sum of squares naturally also increases, therefore X... rms It will rise steadily. This is a fundamental yet effective macroeconomic indicator.

[0063] Crest Factor: The crest factor is the ratio of the peak value of a signal to its RMS value. It is used to quantify the extremes of a signal waveform. A stationary sine wave has a crest factor of... When the bar loosens, the collision between the bar and the trench wall generates a momentary high-amplitude impact (the maximum amplitude Xpeak increases sharply). While the RMS value also increases, its growth rate is far less than that of the peak factor CF. Therefore, the ratio of the two increases significantly. This indicator is highly sensitive to early, sporadic impact signals.

[0064]

[0065] Kurtosis: The kurtosis K of a displacement signal is a fourth-order statistic that is sensitive to the peak characteristics of the vibration distribution. Normal vibrations approximate a Gaussian distribution with a kurtosis of approximately 3 (excess kurtosis is 0). When loosening causes an impact, numerous impact peaks far from the mean appear in the signal, causing the probability distribution to exhibit a "sharp-topped, fat-tailed" shape. This leads to a sharp increase in the fourth moment, thereby causing a sharp increase in the kurtosis value K.

[0066]

[0067] in, The mean, Let Variance be the variance.

[0068] Spectral Centroid: Before calculating spectral parameters, a Fast Fourier Transform (FFT) is performed on the time-domain signal x(n) to obtain its spectrum S(k), where k is the index of a frequency point. |S(k)| represents the amplitude at the k-th frequency point. Under normal, tight conditions, energy is mainly concentrated around 100Hz, so the spectral centroid will stabilize at a relatively low frequency. When loosening occurs, impact and friction generate a large number of high-frequency signals, causing the energy of the spectrum to shift towards higher frequencies, thus significantly increasing the spectral centroid (shifting towards higher frequencies).

[0069]

[0070] Where f(k) represents the actual physical frequency corresponding to the k-th data point in the spectrum, f(k) = (k-1) fs / N, where fs is the sampling frequency of 1kHz, N is the number of FFT points, and k is the frequency point index.

[0071] Spectral variance (SV) measures the dispersion of vibrational energy in the frequency domain, reflecting the frequency complexity of the vibration. The variance of single-frequency vibration is close to 0, while broadband vibration has a large variance. Normal slotted wedge vibration is dominated by a specific frequency, resulting in a small spectral variance. Loosening leads to increased multimodal vibration and random components, increasing the spectral variance. Spectral variance is particularly sensitive to early loosening; spectral broadening can be detected even before a significant increase in amplitude.

[0072]

[0073] Feature extraction not only focuses on the physical meaning of individual features, but more importantly, it constructs a symmetrical multimodal feature framework. Although laser ranging and acoustic monitoring measure different physical quantities, they achieve a unified mathematical expression by extracting the same five features (RMS, peak factor, kurtosis, spectral centroid, and spectral variance). This symmetry gives the 15-dimensional feature vector (5 laser features + 5 acoustic features + 5 operating condition parameters) a regular structure, facilitating deep learning models to learn multimodal correlation patterns in a unified feature space. This avoids the complexity of heterogeneous feature fusion and significantly improves the system's real-time processing capability and detection accuracy.

[0074] This utility model provides an online data acquisition system for generator stator slot wedges based on acoustic-optic monitoring. It combines fiber-optic laser ranging with fiber-optic acoustic monitoring to achieve online detection of stator slot wedge vibration and sound signals. The vibration and sound signals monitored online by this utility model can be used for online detection of generator stator slot wedges. The data acquired by this online data acquisition system for generator stator slot wedges based on acoustic-optic monitoring can be used for online detection of generator stator slot wedges. The detection method includes operating condition parameter acquisition and multi-modal data fusion; specifically including: The operating condition parameter acquisition and preprocessing module plays a crucial role in building the data foundation of the entire system. Its core function is to acquire generator operating status parameters in real time, perform precise time-synchronized fusion with vibration data obtained from the laser ranging module and sound signals from the sound monitoring module, and construct a standardized multi-dimensional data sequence to provide high-quality input data for subsequent deep learning anomaly detection models. A distributed data acquisition architecture is adopted, and multi-sensor fusion technology ensures the integrity, accuracy, and real-time nature of the data, laying a solid data foundation for the intelligent online monitoring of slot wedge loosening.

[0075] Multi-source data acquisition and synchronization mechanism: The system simultaneously collects three main categories of data: laser ranging features (5), acoustic features (5), and operating parameters (5), forming a unified 15-dimensional feature vector. Both the laser ranging and acoustic modules output feature vectors at a frequency of 1 kHz, while the operating parameters are acquired at 1 Hz and interpolated to 1 kHz. Operating parameters include several parameters from stator core vibration, motor start-up time, continuous running time, stator slot temperature, stator core temperature, generator active power, generator reactive power, stator current, stator voltage, power factor, and rotational speed, reflecting the interference of mechanical stress, thermal stress, and electromagnetic force on slot wedge vibration. To ensure the monitoring strategy can flexibly adapt to and efficiently apply to various generator sets, the system runs an adaptive optimization algorithm for operating parameters before initiating online monitoring. This algorithm, based on the analysis of historical equipment operating data, first categorizes all available operating parameters into three pools—mechanical stress, thermal stress, and electromagnetic force—according to their physical mechanisms of action on the slot wedge state. Next, the algorithm utilizes data accumulated by the unit under normal operating conditions to calculate the Pearson correlation between each candidate parameter and all ten acoustic and optical monitoring features (including five laser ranging features and five acoustic features). The absolute values ​​of each correlation coefficient are then averaged to quantify a comprehensive correlation score for each parameter. The system first selects the parameters with the highest scores from each of the three stress category pools to ensure a basic representation of the three core influencing factors. Then, from all remaining candidate parameters, the two with the highest correlation scores are selected as supplementary parameters. Changes in these operating condition parameters significantly affect the vibration and acoustic properties of the stator slot wedges under normal operating conditions; therefore, they must be collected synchronously with vibration data to establish an accurate unsupervised deep learning model: the operating condition-vibration-acoustic correlation model. In one specific implementation, the operating condition parameters are selected from five parameters based on the Pearson correlation: stator core vibration, motor start-up time, continuous running time, stator slot temperature, stator core temperature, generator active power, generator reactive power, stator current, stator voltage, power factor, and rotational speed. In one specific implementation, the operating parameters include five parameters: stator slot temperature, stator core temperature, generator active power, power factor, and rotational speed.

[0076] Temperature data acquisition utilizes the high-precision digital temperature and humidity sensor SHT30, which boasts a measurement accuracy of ±0.3℃ and excellent long-term stability, accurately reflecting stator operating temperature changes. The SHT30 continuously acquires stator slot and stator core temperatures at a frequency of 1Hz via an I2C communication interface. Generator operating parameters are acquired through a standardized communication interface with the existing generator monitoring system, obtaining key operating parameters such as active power, speed, and power factor in real time at a frequency of 1Hz. This interface design avoids redundant sensor deployment, improving system economy and reliability.

[0077] Both laser ranging and acoustic monitoring features include RMS value, peak factor, kurtosis, spectral centroid, and spectral variance. The laser ranging module continuously acquires axial vibration displacement data of the stator slot wedge at a high frequency of 1 kHz. This high sampling rate captures detailed time-domain characteristics and transient changes in the slot wedge vibration. High-frequency sampling is crucial for identifying subtle vibration changes caused by slot wedge loosening, as vibration anomalies in the early stages of loosening often manifest as an increase in high-frequency components or subtle changes in vibration modes. Although the acoustic signal is sampled at a high frequency of 100 kHz to capture high-frequency acoustic emission components, its feature extraction is performed within a time window. Specifically, the system processes the first 100 acoustic sampling points (corresponding to 1 ms of data at a 100 kHz sampling rate) every 1 millisecond (corresponding to 1 kHz), calculating five acoustic features within this window containing 100 data points. This design preserves the high-frequency information of the acoustic signal for accurate feature calculation while reducing the feature output frequency to 1 kHz, perfectly matching the sampling frequency of the laser ranging.

[0078] To ensure accurate correlation of multi-source data from different acquisition frequencies, the system employs a dual time synchronization mechanism combining GPS and the Network Time Protocol (NTP). During startup, the system performs high-precision clock calibration using a GPS receiver to obtain an absolute time reference at the microsecond level. During normal operation, the system maintains synchronization with a standard time server via the NTP protocol, ensuring time reference consistency across all acquisition modules. Each data acquisition module uses a unified UTC timestamp format, recording the precise time information of the acquisition moment in the data packet header, providing a reliable time reference for subsequent data fusion processing.

[0079] Please see Figure 10 As shown, the specific online detection method for generator stator slot wedges includes: S100: Acquire laser ranging data, acoustic monitoring data, and generator operating parameter data for online loosening detection of generator stator slot wedges; S200: Preprocesses laser ranging data, acoustic monitoring data, and generator operating parameter data to obtain laser ranging characteristics, acoustic characteristics, and operating parameters; S300. Input the optical ranging features, acoustic features and operating parameters into the pre-trained self-encoder for anomaly detection to obtain the online loosening detection result of the generator stator slot wedge.

[0080] Please see Figure 11 As shown, the autoencoder includes an input layer, an encoder, a latent layer, a decoder, and an output layer; The input layer has 15 neurons; The encoder consists of three fully connected layers with 32, 16 and 8 neurons respectively. Each fully connected layer is followed by a ReLU activation function and a batch normalization layer. The middle potential layer contains 4 neurons; The decoder adopts a completely symmetrical structure with the encoder. The number of neurons in the three fully connected layers and the output layer are 8, 16, 32 and 15, respectively. The output layer uses a linear activation function.

[0081] A pre-trained autoencoder is obtained through the following steps: The autoencoder is trained using the standard backpropagation algorithm and the Adam optimizer. The initial learning rate can be set to 0.001, and the batch size can be set to 256. An early stopping mechanism is used during training. When the reconstruction error on the validation set has not improved for 20 consecutive rounds, the training is automatically stopped to obtain the pre-trained autoencoder.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. An online data acquisition system for generator stator slot wedges based on acoustic and optical monitoring, characterized in that, include: Laser ranging module; The laser ranging module is installed on the side of the stator lower baffle (1) or on the frame (4) installed on the side of the stator pit, and is used to collect the vibration signal of the end surface of the stator bar (3) by laser; Acoustic monitoring module; the acoustic monitoring module includes an optical fiber acoustic emission sensor (500) fixed on the side frame at the end of the stator bar or an optical fiber acoustic emission probe (201) installed in the stator bar fixing block, for collecting acoustic emission signals of the stator bar (3).

2. The online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring according to claim 1, characterized in that, The laser ranging module adopts a phase-type laser ranging device (2). A phase-type laser ranging device (2) is installed on the side of the lower stator baffle (1); the phase-type laser ranging device (2) includes an annular slide rail (21), a laser ranging module (22) and a track trolley (23) installed on the side of the lower stator baffle (1); the laser ranging module (22) is fixed on the annular slide rail (21) via the track trolley (23); the annular slide rail (21) integrates a power supply, which connects the track trolley (23) and the laser ranging module (22) to provide power to the track trolley (23) and the laser ranging module (22).

3. The online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring according to claim 2, characterized in that, The laser ranging module (22) is a multi-laser emission ranging module (20).

4. The generator stator slot wedge online data acquisition system based on acoustic and optical monitoring according to claim 2, characterized in that, The laser ranging module (22) is a single laser emission ranging module.

5. The online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring according to claim 1, characterized in that, The laser ranging module adopts a phase-type laser ranging device (2). The phase-type laser ranging device (2) is installed on the frame (4) on the side of the stator pit; the phase-type laser ranging device (2) includes an annular slide rail (21), a laser ranging module (22) and a track trolley (23) installed on the frame (4) on the side of the stator pit; the laser ranging module (22) is fixed on the annular slide rail (21) by the track trolley (23).

6. The online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring according to claim 5, characterized in that, It also includes two L-shaped metal brackets (60); Two L-shaped metal brackets (60) are symmetrically arranged and fixed on the side wall of the frame (4); Each L-shaped metal bracket (60) is fixed with a guide rail bracket (210) with an L-shaped cross section, and the guide rail bracket (210) is provided with an annular slide rail (21). The track trolley (23) is mounted on the circular slide rail (21) via the walking mechanism (230).

7. The online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring according to claim 6, characterized in that, The traveling mechanism (230) includes a chassis (2306), a connecting frame (2305), and a retainer (2300). The chassis (2306) is connected to at least two retainers (2300) via a connecting frame (2305); a T-shaped notch is provided in the retainer (2300) corresponding to the annular slide rail (21), the T-shaped notch is fitted onto the annular slide rail (21), and a pair of support wheels (2303) are installed in the T-shaped notch, the pair of support wheels (2303) contact the upper and lower end faces of the annular slide rail (21); The cage (2300) is also equipped with a drive wheel (2301) and a driven wheel (2302); the drive wheel (2301) and the driven wheel (2302) are locked on the upper and lower sides of the annular slide rail (21), and the drive wheel (2301) is connected to the drive motor (2304) located on the cage (2300) to provide power for the track trolley (23) to move along the annular slide rail (21).

8. The online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring according to claim 7, characterized in that, An adjustable gimbal (231) is provided on the chassis (2306), and a laser ranging module (22) is installed on the adjustable gimbal (231).

9. The online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring according to claim 6, characterized in that, A 3mm thick nitrile rubber pad (61) is pasted on the contact surface between the L-shaped metal bracket (60) and the frame (4); a metal-rubber composite shock absorption module (62) is set between the L-shaped metal bracket (60) and the guide rail bracket (210); the metal-rubber composite shock absorption module (62) adopts a three-layer structure of metal-rubber-metal.

10. The online data acquisition system for generator stator slot wedges based on acoustic-optical monitoring according to claim 6, characterized in that, The two guide rail brackets (210) are connected by a U-shaped guide groove (211); the U-shaped guide groove (211) is a non-closed loop structure; the laser ranging module (22) and the track trolley (23) are connected by a drag chain (7) for transmitting signals and providing power; the drag chain (7) is set in the U-shaped guide groove (211), and the inner wall of the U-shaped guide groove (211) is fully covered with a polytetrafluoroethylene lubricating film.

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