Water-turbine generator set axis measuring device and method

Abstract

The invention discloses a hydroelectric generating set stress characteristic on-line monitoring method and system. The method comprises the following steps: A01, carrying out multi-dimensional acquisition on stress data; a02, multi-source data fusion preprocessing is carried out; a03, stress characteristic self-adaptive extraction; A04, stress state modeling and evaluation; a05, stress early warning and dynamic feedback, wherein the system comprises an Internet of Things intelligent sensing node, a data preprocessing module, a feature extraction module, a state evaluation module, an early warning feedback module and a digital twinborn calibration module; according to the method, the SVM-LSTM hybrid model and the SVM module are used for establishing a normal state classifier, the LSTM module outputs a stress prediction value and calculates the deviation degree, the hybrid model combines SVM classification advantages and LSTM prediction capability, a normal state reference is accurately established, the real-time stress state deviation degree is quantified, a scientific basis is provided for state evaluation, and the method has the advantages of being high in reliability and high in reliability. And comparing an evaluation result with a simulation stress value of the digital twin model, and correcting model parameters.

Description

Technical Field

[0001] This invention relates to the field of generator maintenance technology, specifically to a device and method for measuring the shaft axis of a hydro-generator set. Background Technology

[0002] The measurement and adjustment of the turbine generator set's shaft is an important part of the unit's installation, inspection, and maintenance. The purpose of shaft adjustment is to ensure that the three lines—the unit's shaft, the unit's center line, and the main shaft's placement center line—are ideally vertical and coincident. Ideally, under the condition that the three lines coincide, the unit will not produce any sway during rotation. However, in practice, it is impossible to achieve perfect alignment of the three lines; we can only ensure that the deviation of each line is within the standard allowable range.

[0003] Currently, power plants commonly use a rotary head method to measure the relative sway of various parts of a hydro-generator unit, recording data with mechanical dial indicators. However, this method has several significant drawbacks: First, the measurement data has a large error. The accuracy of mechanical dial indicators is typically only 10-20µm, which is insufficient to meet the stringent accuracy requirements of modern hydro-generator units, resulting in measurement results that do not accurately reflect the actual state of the shaft. Second, during the rotary head measurement, the data on the mechanical dial indicator needs to be read manually. This process is easily affected by human factors, such as visual errors during reading and clerical errors during recording, further reducing the accuracy of the measurement data. Third, the number of measuring points is limited. Generally, only 8 measuring points are set for one revolution of the rotary head. Due to the sparse distribution of measuring points, it is impossible to comprehensively and accurately capture the true sway of the shaft during rotation, making it difficult to find the most accurate maximum sway position. This results in a large deviation between the final data and the actual shaft data. In addition, the rotary head device itself is large and complex to operate, which is not only time-consuming and labor-intensive, increasing measurement costs, but also allows measurement work to be carried out only during maintenance periods. This undoubtedly has an adverse impact on power generation plans and reduces the unit's utilization efficiency. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and to provide a device and method for measuring the shaft of a hydro-generator set. This invention effectively solves the problems of low accuracy and high labor and time costs associated with traditional measurement methods, and has significant innovation and practicality.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] On the one hand, there is a hydro-generator shaft measuring device, which uses the X / Y direction as the measurement position reference and consists of an eddy current displacement sensor, an L-shaped angle iron reference base, a data acquisition unit and an analysis and processing unit combined with a computer system;

[0007] The reference base is fixed in the X and Y directions at four planar positions of the unit: upper guide, lower guide, flange, and water guide.

[0008] The eddy current displacement sensor is fixed on the reference base and connected to the data acquisition unit via a three-phase shielded cable.

[0009] The analysis and processing unit can process the collected signals to obtain shaft-related data.

[0010] Furthermore, the reference base is an L-shaped angle iron, fixed in two mutually 90° X and Y directions at the four planar positions of the upper guide, lower guide, flange, and water guide. One reference base is placed in each of the upper guide X, upper guide Y, lower guide X, lower guide Y, flange X, flange Y, water guide X, and water guide Y. The reference base is fixed in a non-rotating position near the turbine and generator by fixing glue or magnetic base, and an adjustment mechanism is provided on it.

[0011] Furthermore, the eddy current displacement sensor is fixed to the reference base by bolts fastening it to both sides of the L-angle iron through bolt through-holes. Each eddy current displacement sensor is equipped with an adjustment bolt that cooperates with the base through-hole to achieve horizontal distance adjustment. The sensor is of the eddy current type, powered by -24V, and the signal output is voltage-type. During the rotation of the rotating shaft, the distance between the sensor and the shaft surface is measured by an electromagnetic induction coil. The distance from the rotating shaft surface during measurement ensures that the sensor displays a value of 10V, so as to ensure that the measurement data is within the range.

[0012] Furthermore, the eddy current displacement sensor uses the principle of electromagnetic induction for measurement. In the sensor system, the high-frequency oscillating current in the preamplifier flows into the probe coil through the extension cable, generating an alternating magnetic field in the probe head coil. When the metal object being measured approaches this magnetic field, an induced current is generated on its surface, and at the same time, the eddy current field generates an alternating magnetic field in the opposite direction to that of the head coil. The change in distance between the head coil and the metal conductor is converted into a change in voltage or current, and the magnitude of the output signal varies with the distance between the probe and the surface of the object being measured, thereby realizing the measurement of the displacement parameters of the metal object.

[0013] Furthermore, the data acquisition unit is connected to the eddy current displacement sensor via a three-phase shielded cable, receiving the X / Y direction voltage signals from the upper conductor, lower conductor, flange, and water conductor of the unit. It continuously records the displacement voltage signals of the eddy current step by step, with a sampling frequency of not less than 10 times the frequency. After acquiring the data, it selects the frequency filtering function to filter out high-frequency noise interference data.

[0014] Furthermore, the analysis and processing unit is combined with the computer system to form a data processing and analysis module unit. Through trajectory mapping, the bearing runout data of each part of the complete cycle is obtained. Taking the upper guide as the reference object, the runout of the lower guide, flange, and water guide is corrected for the runout of the upper guide by removing the data correction of the upper guide runout during the same period, and the runout of the three parts relative to the upper guide is obtained. The shaft system deflection angle of each part is calculated by conversion, and it is determined whether the shaft system deflection meets the standard.

[0015] On the other hand, a method for measuring the shaft of a hydro-generator set includes the following specific steps:

[0016] Equipment Deployment and Calibration: Fix the L-shaped angle iron reference base to the positions of upper guide X, upper guide Y, lower guide X, lower guide Y, flange X, flange Y, water guide X, and water guide Y using adhesive or magnetic base. Set a key phase block at water guide X. The eddy current displacement sensor passes through the bolt holes of the L-shaped angle iron and is fixed by the fastening bolts on both sides. Adjust the sensor so that the displayed value is 10V. Connect the sensor and the data acquisition unit using a three-phase shielded cable to complete the circuit continuity test.

[0017] Measurement timing control: Select the unit's rollover and shutdown process, ensure that the brakes are not engaged, and start the data acquisition program when the speed drops to less than 5% of the rated speed, using the key phase block to trigger the complete cycle data recording mechanism;

[0018] Dynamic data acquisition: The data acquisition unit continuously records the voltage signals output by each sensor at a sampling frequency of no less than 10 times the rotation frequency, synchronously stores the key phase marking information, and forms a raw dataset containing timestamps. The acquisition time covers at least 3 complete rotation cycles.

[0019] Data Analysis and Evaluation: The analysis and processing unit processes the collected data, using frequency filtering to remove high-frequency noise interference. It obtains bearing runout data for a complete cycle through trajectory mapping, converting the voltage signal into corresponding runout displacement signals. Using the upper guide as a reference, it corrects the runout data of the lower guide, flange, and water guide, eliminating the influence of the upper guide runout. Based on the corrected runout data, it calculates the shaft deflection angle for each part and determines whether the shaft deflection meets the standards.

[0020] Furthermore, in the data analysis and evaluation step, the voltage signal is converted into a swing displacement signal, and the conversion formula is as follows: ,in, This is the swing displacement signal, i.e., the actual swing values ​​of the upper guide, lower guide, flange, and water guide in the X / Y directions. The conversion coefficient was determined by the eddy current sensor calibration experiment. This refers to the real-time voltage signal received by the data acquisition unit. This is the initial voltage reference value. This is the initial displacement reference value, i.e., the initial distance between the sensor and the rotating axis.

[0021] Furthermore, in the data analysis and evaluation step, the swing data of the lower guide, flange, and water guide are corrected with reference to the upper guide. The correction formula is as follows: ,in, For the first The relative swing of each measurement point relative to the upper guide. For the first The absolute sway of each part, For the first The distance between each part and the unit's fixed reference point The distance between the upper guide and the fixed reference point of the unit. The absolute swing of the upper guide.

[0022] Furthermore, in the data analysis and evaluation step, the shaft deflection angle of each part is calculated based on the corrected sway data, and the conversion formula is as follows: ,in, For the first The angle of deflection of the shaft system at each part For the first The relative sway of each part in the X direction For the first The relative sway of each part in the Y direction For the first The axial distance between each part and the upper guide.

[0023] Compared with existing technologies, the hydro-generator set shaft measuring device and method have the following advantages:

[0024] I. This invention employs an eddy current displacement sensor combined with a reference base and a data acquisition unit. The eddy current displacement sensor can directly and non-contactly measure the state of the rotating shaft and accurately collect data. It adopts the principle of electromagnetic induction, measuring the distance to the shaft surface through an electromagnetic induction coil, which greatly improves the measurement accuracy. At the same time, the sampling frequency of the data acquisition unit is no less than 10 times the rotational frequency, and it can also filter out high-frequency noise interference data, so as to obtain the most accurate trajectory of each part of the bearing. It effectively solves the problems of large errors and inability to find the true maximum swing position of traditional measurement methods, and provides a reliable reference for the evaluation of unit installation quality and shaft adjustment.

[0025] Second, this invention utilizes the unit's shutdown phase for measurement, eliminating the need for a turning gear and over maintenance time constraints. The equipment can be installed during downtime and testing can commence immediately without affecting power generation. Furthermore, the device achieves intelligent data acquisition, data filtering, and automatic trajectory generation, avoiding errors from manual readings, reducing manual operation steps, significantly lowering maintenance manpower and time costs, and improving measurement efficiency. This greatly facilitates the maintenance, installation, and upkeep of hydroelectric generator units.

[0026] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0028] Figure 1 A schematic diagram showing the sensor installation location of the shaft measuring device for a hydro-generator unit;

[0029] Figure 2 A periodic waveform diagram obtained by the shaft measurement method of a hydro-generator unit;

[0030] Figure 3 This is a flowchart of the method for measuring the axis of a hydro-generator unit. Detailed Implementation

[0031] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0032] Example 1

[0033] This invention proposes a shaft measuring device for a hydro-generator set. The device uses the X / Y directions as the measurement position reference and consists of a measuring unit with an eddy current displacement sensor, an L-shaped angle iron reference base, a data acquisition unit, and an analysis and processing unit integrated with a computer system. The reference base is fixed in the X and Y directions at four plane positions of the generator set: the upper guide, lower guide, flange, and water guide. The eddy current displacement sensor is fixed on the reference base and connected to the data acquisition unit through a three-phase shielded cable. The analysis and processing unit can process the acquired signals to obtain shaft-related data.

[0034] The reference base is an L-shaped angle iron, fixed in two X and Y directions at 90° to each other on the four plane positions of the upper guide, lower guide, flange, and water guide. One reference base is placed on each of the upper guide X, upper guide Y, lower guide X, lower guide Y, flange X, flange Y, water guide X, and water guide Y. The reference base can be fixed to a non-rotating position near the turbine and generator by fixing glue or magnetic base, and an adjustment mechanism is provided on it.

[0035] The eddy current displacement sensor is fixed to the reference base by bolts passing through the bolt holes of the L-angle iron and being fastened to both sides of the L-angle iron by fastening bolts. Figure 1 As shown, each eddy current displacement sensor is equipped with an adjustment bolt that engages with the through hole in the base to achieve horizontal distance adjustment. The sensor is of the eddy current type, powered by -24V, and the signal output is a voltage output. It can measure the distance between the sensor and the shaft surface through an electromagnetic induction coil during the rotation of the rotating shaft. During measurement, the distance from the rotating shaft surface should be such that the sensor displays a value of 10V to ensure that the measurement data is within the range.

[0036] Eddy current displacement sensors use the principle of electromagnetic induction for measurement: In the sensor system, a high-frequency oscillating current in the preamplifier flows into the probe coil through an extension cable, generating an alternating magnetic field in the probe head coil; when the metal object being measured approaches this magnetic field, an induced current is generated on its surface, and at the same time, the eddy current field generates an alternating magnetic field in the opposite direction to that of the head coil; the change in distance between the head coil and the metal conductor is converted into a change in voltage or current, and the magnitude of the output signal varies with the distance between the probe and the surface of the object being measured, thereby realizing the measurement of the displacement parameters of the metal object.

[0037] The data acquisition unit is connected to the eddy current displacement sensor via a three-phase shielded cable. It can receive the X / Y direction voltage signals from the upper conductor, lower conductor, flange, and water conductor of the unit to realize data acquisition, analysis, and processing. It can continuously record the displacement voltage signal of the eddy current step by step, with a sampling frequency of not less than 10 times the rotational frequency. After acquiring the data, a frequency filtering function can be selected to filter out high-frequency noise interference data in order to obtain the most accurate trajectory of each bearing part.

[0038] The analysis and processing unit, combined with the computer system, forms a data processing and analysis module unit. This module has automated data analysis and processing capabilities, obtaining bearing runout data for each part of a complete cycle through trajectory mapping. Figure 2 As shown, the upper guide is then used as a reference object. During the same period, the swing of the lower guide, flange, and water guide is adjusted to remove the data correction for the swing of the upper guide. The swing of these three parts relative to the upper guide is obtained. The shaft deflection angle of each part is calculated to determine whether the shaft deflection meets the standard, providing data reference for the evaluation of maintenance and installation quality.

[0039] Example 2

[0040] This embodiment provides a method for measuring the shaft of a hydro-generator set, such as... Figure 3 As shown, it includes:

[0041] First, clean the mounting surfaces of the upper guide bearing housing, lower guide bearing housing, flange, and water guide bearing housing with anhydrous ethanol to remove oil and rust, ensuring that the reference base is firmly fixed. Fix the eight L-shaped angle iron reference bases (made of high-strength alloy) to the X and Y directions of each plane (at 90° to each other) using epoxy resin adhesive or magnetic bases. The upper guide X-direction base is located on the right side of the front face of the bearing housing, the upper guide Y-direction base is located on the upper side of the front face, and the bases of the lower guide, flange, and water guide are arranged in the corresponding positions.

[0042] Next, pass the eddy current displacement sensor (-24V power supply, voltage output) through the bolt through hole of the L-shaped angle iron, and clamp it with M8 fastening bolts on both sides. Then rotate the adjusting bolt at the tail of the sensor and monitor it in real time with the data acquisition device until the sensor display value stabilizes at 10V (at this time, the distance between the probe and the shaft surface is 1mm, which is within the optimal range).

[0043] Finally, connect the sensor and the data acquisition unit with a 5-meter-long three-phase shielded cable, with the shielding layer grounded at one end (grounding resistance ≤ 4Ω). After powering on, test the signals of each channel to ensure there is no noise or broken wires, confirming that the device is installed correctly.

[0044] After the generator completes its power generation task and the load drops to 0MW, it enters the deceleration and shutdown stage. The braking system is turned off, allowing the generator to decelerate naturally by inertia. The generator speed is monitored in real time by a speed sensor. When the speed drops to less than 5% of the rated speed (e.g., when the rated speed is 300rpm, it drops to less than 15rpm), the data acquisition program is started in the computer system to synchronously record the measurement start time and the initial speed.

[0045] Dynamic data acquisition is performed using a data acquisition device that operates according to preset parameters. The sampling frequency is set to 100Hz (for a 300rpm unit, the rotation frequency is 5Hz, and the sampling frequency is 20 times the rotation frequency). The device continuously acquires the X / Y direction voltage signals of each sensor. During the acquisition process, the system automatically marks the triggered cycle nodes to ensure that a complete data segment is generated for each rotation. The total acquisition time covers 15 cycles (approximately 120 seconds) to reduce random errors. The data is stored in real time to the computer hard drive in CSV format, including timestamps, voltage values ​​of each channel, rotation speed, and key phase markings, which facilitates subsequent traceability and verification.

[0046] The collected data is analyzed and the shaft deflection is evaluated. First, the analysis and processing unit (equipped with custom data processing software) imports the raw data, removes power grid interference and high-frequency vibration noise through 50Hz notch filtering and 10Hz low-pass filtering, and extracts the effective waveforms of three consecutive complete cycles for each part. Then, the effective waveforms are obtained through formulas. The voltage signal is converted into yaw displacement (unit: mm), where (Sensor calibration coefficient) (Initial voltage reference) (Initial distance), for example, when the voltage in the X direction of the lower guide is 9.8V at a certain moment, the corresponding swing is... Next, using the above guide oscillation as a benchmark, through the formula... Calculate the relative swing, where This is the distance between the lower guide and the fixed reference point (e.g., 2m). This is the distance between the upper guide and the fixed reference point (e.g., 1m). The upper guide oscillation (e.g., 0.9 mm) represents the lower guide absolute oscillation. The relative swing Finally, according to the formula Conversion of shaft system deflection angle ( (This refers to the axial distance between the lower and upper guides, e.g., 1.2m). When the relative runout of the lower guides in the X and Y directions is -0.82mm and 0.3mm respectively, Deflection angle The software generates a swing trajectory diagram, compares it with industry standards, and outputs an evaluation report containing raw data, processing results, and maintenance suggestions.

[0047] This invention leverages the advantages of eddy current displacement sensors, employing eddy current signal sensors to acquire measurement data. Combined with data acquisition and processing technologies, it improves data accuracy and obtains accurate swing period data, thereby accurately assessing the swing and shaft deflection at various points on the hydro-generator. By setting a reference base and eddy current displacement sensors at specific locations, and equipping them with data acquisition and analysis units, this invention achieves precise measurement of the hydro-generator shaft. The measurement process utilizes the unit's shutdown phase, eliminating the need for a turning gear. This not only efficiently acquires swing data from various parts but also allows for timely data processing and analysis, providing a reliable reference for evaluating unit installation quality and shaft adjustment.

[0048] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0049] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0050] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0051] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0052] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A device for measuring the shaft axis of a hydro-generator set, characterized in that, The device uses the X / Y direction as the measurement position reference and includes an eddy current displacement sensor, an L-shaped angle iron reference base, a data acquisition unit, and an analysis and processing unit integrated with a computer system. The reference base is fixed in the X and Y directions at four planar positions of the unit: upper guide, lower guide, flange, and water guide. The eddy current displacement sensor is fixed on the reference base and connected to the data acquisition unit via a three-phase shielded cable. The analysis and processing unit can process the collected signals to obtain shaft-related data.

2. The hydro-generator set shaft measuring device according to claim 1, characterized in that, The reference base is an L-shaped angle iron, fixed in two X and Y directions at 90° to each other on the four plane positions of the upper guide, lower guide, flange, and water guide. One reference base is placed on each of the upper guide X, upper guide Y, lower guide X, lower guide Y, flange X, flange Y, water guide X, and water guide Y. The reference base is fixed to a non-rotating position near the turbine and generator by fixing glue or magnetic base, and an adjustment mechanism is provided on it.

3. The hydro-generator set shaft measuring device according to claim 1, characterized in that, The eddy current displacement sensor is fixed to the reference base by bolts fastening it to both sides of the L-angle iron through bolt through-holes. Each eddy current displacement sensor is equipped with an adjustment bolt that cooperates with the base through-hole to achieve horizontal distance adjustment. The signal output of the eddy current displacement sensor is a voltage type output. During the rotation of the rotating shaft, the distance between the sensor and the shaft surface is measured by an electromagnetic induction coil. The distance from the rotating shaft surface during measurement is set to a preset value to ensure that the measurement data is within the range.

4. The hydro-generator set shaft measuring device according to claim 1, characterized in that, The eddy current displacement sensor uses the principle of electromagnetic induction for measurement. In the sensor system, the high-frequency oscillating current in the preamplifier flows into the probe coil through the extension cable, generating an alternating magnetic field in the probe head coil. When the metal object being measured approaches this magnetic field, an induced current is generated on its surface, and at the same time, the eddy current field generates an alternating magnetic field in the opposite direction to that of the head coil. The change in distance between the head coil and the metal conductor is converted into a change in voltage or current. The magnitude of the output signal varies with the distance between the probe and the surface of the object being measured, thereby realizing the measurement of the displacement parameters of the metal object.

5. The hydro-generator set shaft measuring device according to claim 1, characterized in that, The data acquisition unit is connected to the eddy current displacement sensor via a three-phase shielded cable. It receives the X / Y direction voltage signals from the upper conductor, lower conductor, flange, and water conductor of the unit, and records the displacement voltage signals of the eddy current step by step. The sampling frequency is not lower than the preset frequency, and after acquiring the data, the frequency filtering function is selected to filter out high-frequency noise interference data.

6. The hydro-generator set shaft measuring device according to claim 1, characterized in that, The analysis and processing unit obtains bearing runout data for each part of the complete cycle by tracing the trajectory. Taking the upper guide as a reference, the runout of the lower guide, flange, and water guide is adjusted to remove the data correction of the upper guide runout during the same period to obtain the runout of the three parts relative to the upper guide. The shaft system deflection angle of each part is calculated to determine whether the shaft system deflection meets the standard.

7. A method for measuring the axis of a hydro-generator unit, applicable to the hydro-generator unit axis measuring device according to any one of claims 1-6, characterized in that, The method includes the following specific steps: The L-shaped angle iron reference base is fixed to the positions of upper guide X, upper guide Y, lower guide X, lower guide Y, flange X, flange Y, water guide X, and water guide Y using fixing glue or magnetic base. A key phase block is set at water guide X. The eddy current displacement sensor passes through the bolt through hole of the L-shaped angle iron and is fixed by the fastening bolts on both sides. The sensor is adjusted so that the displayed value is the preset value. A three-phase shielded cable is used to connect the sensor and the data acquisition unit to complete the circuit continuity test. During the selected unit shutdown process, ensure that the brakes are not engaged. When the speed drops below the preset ratio of the rated speed, start the data acquisition program and use the key phase block to trigger the complete cycle data recording mechanism. Dynamic data acquisition: The data acquisition unit continuously records the voltage signals output by each sensor at a preset sampling frequency, synchronously stores the key phase marker information, and forms a raw dataset containing timestamps. The acquisition time covers at least 3 complete rotation cycles. The analysis and processing unit processes the collected data, uses frequency filtering to remove high-frequency noise interference, obtains bearing runout data for a complete cycle through trajectory mapping, converts the voltage signal into the corresponding runout displacement signal, and corrects the runout data of the lower guide, flange, and water guide with the upper guide as a reference to eliminate the influence of the upper guide runout. Based on the corrected runout data, the shaft system deflection angle of each part is calculated to determine whether the shaft system deflection meets the standard.

8. The method for measuring the shaft of a hydro-generator unit according to claim 7, characterized in that, In the data analysis and evaluation step, the voltage signal is converted into a swing displacement signal, and the conversion formula is as follows: ， in, This is the swing displacement signal, i.e., the actual swing values ​​of the upper guide, lower guide, flange, and water guide in the X / Y directions. The conversion coefficient was determined by the eddy current sensor calibration experiment. This refers to the real-time voltage signal received by the data acquisition unit. This is the initial voltage reference value. This is the initial displacement reference value, i.e., the initial distance between the sensor and the rotating axis.

9. The method for measuring the shaft of a hydro-generator unit according to claim 7, characterized in that, Using the upper guide as a reference, the swing data of the lower guide, flange, and water guide are corrected using the following formula: ， in, For the first The relative swing of each measurement point relative to the upper guide. For the first The absolute sway of each part, For the first The distance between each part and the unit's fixed reference point The distance between the upper guide and the fixed reference point of the unit. The absolute swing of the upper guide.

10. The method for measuring the shaft of a hydro-generator unit according to claim 7, characterized in that, Based on the corrected runout data, the shaft deflection angle of each part is calculated, and the conversion formula is as follows: ， in, For the first The angle of deflection of the shaft system at each part For the first The relative sway of each part in the X direction For the first The relative sway of each part in the Y direction For the first The axial distance between each part and the upper guide.

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