Method for solving abnormal speed measurement caused by excessive vibration of slip ring

Abstract

The invention provides a method for solving abnormal speed measurement caused by overlarge vibration of a slip ring, and relates to the technical field of wind turbine generators, comprising the following steps: S1, stopping and powering off the wind turbine generator set, and dismounting an original proximity switch at the slip ring; s2, a novel proximity switch is installed at a slip ring code disc measurement position; s3, a filler gauge is used for calibrating the distance between the novel proximity switch and the slip ring code disc, so that the distance between the novel proximity switch and the slip ring code disc is adjusted to a preset range, and dynamic working condition calibration is carried out; and S4, a novel proximity switch mounting nut is locked, and a fastening mark is marked on the nut. The stability of the slip ring code disc in actual operation can be verified through dynamic working condition calibration, the vibration and wear resistance of the surface of the slip ring code disc can be enhanced by spraying the vibration and wear resistant coating, the service life of parts can be prolonged, the vibration impact force can be monitored in real time by embedding the piezoelectric film sensor, fault early warning is achieved, non-planned shutdown is reduced, and the service life of the slip ring code disc is prolonged. And the fault occurrence rate caused by abnormal speed measurement of the proximity switch is effectively reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wind turbine units, and particularly relates to a solution to speed measurement abnormality caused by excessive vibration of a slip ring. BACKGROUND

[0002] With the development of wind turbine units in the direction of high power and high reliability, the measurement accuracy of the slip ring system as a core component for monitoring the rotating speed of a blade directly affects the safe and stable operation of the unit. In wind turbine units, the problem of speed measurement abnormality of a proximity switch caused by excessive vibration of a slip ring is particularly prominent, and often causes cascading failures such as overspeed of a blade, overspeed of a variable pitch, and overspeed of a generator safety chain, which seriously affects the operation reliability of the unit.

[0003] The traditional proximity switch has insufficient anti-vibration performance, and the hysteresis anti-vibration range thereof is difficult to adapt to the vibration amplitude of the slip ring under complex working conditions, resulting in jump or loss of the rotating speed signal. The existing fault handling schemes mostly adopt passive methods such as software filtering or threshold adjustment, and cannot fundamentally solve the problem of the vibration source, so it is difficult to realize long-term stable operation of the speed measurement system. In addition, the manual static calibration mechanism ignores the change of the vibration characteristics of the slip ring under dynamic working conditions, and cannot guarantee the accurate matching of the distance between the proximity switch and the code disc, thereby affecting the speed measurement accuracy. SUMMARY

[0004] The application provides a solution to speed measurement abnormality caused by excessive vibration of a slip ring, to solve at least one of the technical problems mentioned above.

[0005] To solve the above technical problems, the application discloses a solution to speed measurement abnormality caused by excessive vibration of a slip ring, comprising the following steps:

[0006] S1, stopping the wind turbine unit and disconnecting the power, and removing the original proximity switch at the slip ring;

[0007] S2, installing a new proximity switch to the measurement position of the slip ring code disc;

[0008] S3, using a feeler gauge to calibrate the distance between the new proximity switch and the slip ring code disc, so that the distance between the new proximity switch and the slip ring code disc is adjusted to a preset range, and dynamic working condition calibration is performed;

[0009] S4, locking the installation nut of the new proximity switch, and marking a tightening mark at the nut.

[0010] Preferably, the preset range between the new proximity switch and the slip ring code disc in step S3 is 1.0-1.5 mm.

[0011] Preferably, before step S2, the surface of the slip ring code disc is also sprayed with an anti-vibration wear-resistant coating.

[0012] The anti-vibration wear coating composition is a tungsten carbide-cobalt cermet composite, and the spraying thickness ranges from 50 to 100 microns.

[0013] Preferably, the step of dynamic working condition calibration comprises:

[0014] S31, start the unit and raise the impeller speed to the range of 12 rpm to 48 rpm;

[0015] S32, synchronously monitor the vibration spectrum of the X, Y and Z axes of the slip ring through the three-axis accelerometer, and calculate the vibration acceleration root mean square value of any axis in the 5-15Hz frequency band and the signal-to-noise ratio of the new proximity switch gain based on the vibration spectrum of the X, Y and Z axes of the slip ring;

[0016] S33, based on the vibration spectrum of the X, Y and Z axes of the slip ring monitored by the three-axis accelerometer, calculate the comprehensive installation reliability coefficient of the new proximity switch;

[0017] S34, determine whether the vibration acceleration root mean square value of any axis in the 5-15Hz frequency band meets the target formula one, and whether the signal-to-noise ratio of the new proximity switch gain meets the target formula two, and whether the comprehensive installation reliability coefficient of the new proximity switch is greater than the preset comprehensive installation reliability coefficient of the new proximity switch, if yes, proceed to step S4, otherwise repeat step S3.

[0018] Preferably, the signal-to-noise ratio of the new proximity switch gain of any axis in the 5-15Hz frequency band is:

[0019] Wherein, SNR is the signal-to-noise ratio of the new proximity switch gain, S is the amplitude of the impeller speed signal, and N is the amplitude of the background noise;

[0020] Target formula one:

[0021]

[0022] Wherein, a x , a y and a z respectively represent the vibration acceleration root mean square value in the 5-15Hz frequency band calculated by the vibration spectrum of the X, Y and Z axes of the slip ring, and f is the vibration frequency of the slip ring;

[0023] Target formula two:

[0024] SNR≥18dB.

[0025] Preferably, based on the vibration spectrum of the X, Y and Z axes of the slip ring monitored by the three-axis accelerometer, the comprehensive installation reliability coefficient of the new proximity switch is calculated, including:

[0026] S331, based on the vibration frequency spectrum of the slip ring X, Y, Z axis monitored by each monitoring period, the vibration severity coefficient of the slip ring in X, Y, Z axis is calculated;

[0027] S332, based on the vibration severity coefficient of the slip ring in X, Y, Z axis, the comprehensive installation reliability coefficient of the new proximity switch is calculated.

[0028] Preferably, the vibration severity coefficient of the slip ring in X axis is:

[0029] Wherein, U x is the vibration severity coefficient of the slip ring in X axis, a xi is the vibration acceleration root mean square value in 5-15Hz frequency band calculated by the vibration frequency spectrum of the slip ring X axis in the i th monitoring period, e is a natural number, the value is 2.71, f0 is the resonance natural frequency of the slip ring;

[0030] The vibration severity coefficient of the slip ring in Y axis is:

[0031] Wherein, U y is the vibration severity coefficient of the slip ring in Y axis, a yi is the vibration acceleration root mean square value in 5-15Hz frequency band calculated by the vibration frequency spectrum of the slip ring Y axis in the i th monitoring period;

[0032] The vibration severity coefficient of the slip ring in Z axis is:

[0033] Wherein, U z is the vibration severity coefficient of the slip ring in Z axis, a zi is the vibration acceleration root mean square value in 5-15Hz frequency band calculated by the vibration frequency spectrum of the slip ring Z axis in the i th monitoring period.

[0034] Preferably, the comprehensive installation reliability coefficient of the new proximity switch is:

[0035] Wherein, W is the comprehensive installation reliability coefficient of the new proximity switch, ω1, ω2 and ω3 are the weight values of the vibration severity coefficient of the slip ring in X axis, the vibration severity coefficient of the slip ring in Y axis and the vibration severity coefficient of the slip ring in Z axis respectively.

[0036] Preferably, step S2 further includes heat dissipation strengthening treatment;

[0037] The aluminum alloy heat dissipation fin group is additionally installed on the new proximity switch body, the fin contact surface with the proximity switch is smeared with heat-conducting silicone, and the wedge-shaped damping block is additionally installed on the slip ring base.

[0038] Preferably, it further comprises step S5: embedding the piezoelectric film sensor at the mounting bracket to collect the axial force data of the new proximity switch in real time, and when the vibration impact force is monitored for 3 times continuously > the preset vibration impact force, a maintenance holding prompt is given.

[0039] Compared with the prior art, the present application has the following beneficial effects:

[0040] The present application ensures the safety of the operation process by stopping power and standardizing the dismounting and mounting steps, the installation and spacing calibration of the new proximity switch can accurately measure the impeller rotating speed at the slip ring, the dynamic working condition calibration can verify the stability of the proximity switch in actual operation, the spraying of the anti-vibration wear coating can enhance the anti-vibration wear capacity of the slip ring code disc surface, prolong the service life of the component, and the embedded piezoelectric film sensor can monitor the vibration impact force in real time, realize early fault warning, and reduce unplanned shutdown. BRIEF DESCRIPTION OF DRAWINGS

[0041] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the present application and explain the principles of the present application, and do not constitute a limitation of the present application. In the drawings:

[0042] Figure 1 It is a schematic diagram of the solution method of the present application based on the excessive vibration of the slip ring leading to speed measurement abnormality. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and do not limit the present application.

[0044] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and does not mean to specially indicate the order or sequence, nor to limit the present application, which is only to distinguish the components or operations described by the same technical terms, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features of various embodiments can be combined with each other, but it must be based on the realization of a person skilled in the art, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the scope of protection required by the present application.

[0045] The present application provides the following embodiments

[0046] Embodiment 1

[0047] The embodiment of the present application provides a solution to abnormal speed measurement caused by excessive vibration of a slip ring. Figure 1 As shown in the figure, the method comprises the following steps:

[0048] S1, stopping and powering off a wind turbine generator set, and removing an original proximity switch at a slip ring;

[0049] S2, installing a new proximity switch to a measurement position of a slip ring code disc;

[0050] S3, using a feeler gauge to calibrate the distance between the new proximity switch and the slip ring code disc, so that the distance between the new proximity switch and the slip ring code disc is adjusted to a preset range, and dynamic working condition calibration is performed;

[0051] S4, locking a mounting nut of the new proximity switch, and marking a fastening mark at the nut.

[0052] Preferably, before the step S2, the method further comprises spraying an anti-vibration wear-resistant coating on a surface of the slip ring code disc;

[0053] The anti-vibration wear-resistant coating is composed of a tungsten carbide-cobalt metal ceramic composite, and the spraying thickness ranges from 50 to 100 microns.

[0054] Preferably, the method further comprises a step S5: embedding a piezoelectric film sensor at a mounting bracket to collect axial force data of the new proximity switch in real time, and issuing a maintenance holding prompt when it is monitored that the vibration impact force is greater than a preset vibration impact force for three times in succession.

[0055] The working principle and beneficial effects of the above technical solution are as follows: after the wind turbine generator set is stopped and powered off, the original proximity switch at the slip ring is safely removed, the new proximity switch is installed to the measurement position of the slip ring code disc, the distance between the new proximity switch and the slip ring code disc is calibrated to a preset range of 1.0-1.5 mm using the feeler gauge, dynamic working condition calibration is performed to verify the installation effect, after completion, the mounting nut of the new proximity switch is locked and a fastening mark is marked, and before the step S2, the surface of the slip ring code disc is sprayed with an anti-vibration wear-resistant coating composed of a tungsten carbide-cobalt metal ceramic composite and having a thickness of 50-100 microns, a piezoelectric film sensor is embedded at a mounting bracket to collect axial force data of the new proximity switch in real time, and a maintenance holding prompt is issued when it is monitored that the vibration impact force is greater than a preset vibration impact force for three times in succession.

[0056] The installation and spacing calibration of the new proximity switch can accurately measure the impeller rotating speed at the slip ring, the dynamic working condition calibration can verify the stability in actual operation, the anti-vibration and wear coating can enhance the anti-vibration and wear capacity of the slip ring code disc surface, prolong the service life of the component, the embedded piezoelectric film sensor can monitor the vibration impact force in real time, realize the early warning of failure, and reduce the unplanned shutdown. The method effectively reduces the failure rate caused by abnormal speed measurement of the proximity switch, improves the operation reliability of the unit, reduces the unit shutdown maintenance time, reduces the operation and maintenance cost, the implementation process is clear, easy for on-site operation, and improves the technical transformation efficiency.

[0057] Embodiment 2

[0058] On the basis of embodiment 1, the step of dynamic working condition calibration comprises:

[0059] S31, start the unit and increase the impeller rotating speed to the interval of 12 rpm to 48 rpm;

[0060] S32, synchronously monitor the vibration frequency spectrum of the X, Y and Z axes of the slip ring through the three-axis accelerometer, calculate the vibration acceleration root mean square value of any axis in the frequency band of 5-15 Hz and the signal-to-noise ratio of the new proximity switch gain based on the vibration frequency spectrum of the X, Y and Z axes of the slip ring;

[0061] S33, calculate the comprehensive installation reliability coefficient of the new proximity switch based on the vibration frequency spectrum of the X, Y and Z axes monitored by the three-axis acceleration;

[0062] S34, judge whether the vibration acceleration root mean square value of any axis in the frequency band of 5-15 Hz meets the target formula one, whether the signal-to-noise ratio of the new proximity switch gain meets the target formula two, and whether the comprehensive installation reliability coefficient of the new proximity switch is greater than the preset comprehensive installation reliability coefficient of the new proximity switch, if yes, proceed to step S4, otherwise repeat step S3.

[0063] The working principle and beneficial effects of the above technical solution are as follows: when the dynamic working condition calibration is started, the unit is started and the impeller rotating speed is increased to the interval of 12 rpm to 48 rpm, the vibration frequency spectrum of the X, Y and Z axes of the slip ring is synchronously monitored through the three-axis accelerometer, the vibration acceleration root mean square value of any axis in the frequency band of 5-15 Hz and the signal-to-noise ratio of the new proximity switch gain are calculated based on the monitoring data, the comprehensive installation reliability coefficient of the new proximity switch is calculated based on the vibration frequency spectrum monitored by the three-axis acceleration, it is judged whether the vibration acceleration root mean square value of any axis in the frequency band of 5-15 Hz meets the target formula one, whether the signal-to-noise ratio of the new proximity switch gain meets the target formula two, and whether the comprehensive installation reliability coefficient of the new proximity switch is greater than the preset value, if yes, proceed to the locking step, otherwise repeat the dynamic working condition calibration step;

[0064] Dynamic operating condition calibration simulates the actual operating speed range of the unit and comprehensively monitors the vibration of the slip ring under different operating conditions. The three-axis accelerometer simultaneously monitors the vibration spectrum of the X, Y, and Z axes, accurately obtains the vibration data of each axis, calculates the root mean square value of the vibration acceleration and the signal-to-noise ratio, and can quantitatively evaluate the impact of vibration on speed measurement. The calculation of the comprehensive installation reliability coefficient further judges the installation stability as a whole. Through multi-dimensional parameter judgment and cyclic calibration mechanism, it ensures that the new proximity switch can stably output accurate speed data in actual operation, avoids false overspeed alarms caused by vibration interference, effectively improves speed measurement stability, and reduces the occurrence of faults. In addition, this dynamic calibration process can specifically solve the speed measurement abnormality problem caused by slip ring vibration, thereby improving the reliability and stability of unit operation.

[0065] Example 3

[0066] Based on Example 2, the gain of the new proximity switch on any axis in the 5-15 Hz frequency band makes the signal-to-noise ratio:

[0067] Among them, SNR is the signal-to-noise ratio of the new proximity switch gain, S is the impeller speed signal amplitude, and N is the background noise amplitude;

[0068] Target formula 1:

[0069]

[0070] Among them, a x 、a y and a z They represent the RMS values ​​of the vibration acceleration in the 5-15 Hz frequency range calculated from the vibration spectra of the slip ring along the X, Y, and Z axes, respectively. f is the vibration frequency of the slip ring.

[0071] Target formula 2:

[0072] SNR≥18dB.

[0073] The working principle and beneficial effects of the technical solution are as follows: the signal-to-noise ratio formula converts the amplitude ratio of the signal and the noise into a decibel value through logarithmic operation, directly reflects the signal quality, and is convenient for judging the gain adjustment effect; the target formula one corrects the acceleration threshold value based on the vibration frequency f, when f is 10 Hz, the threshold value is 3.5 g, when f changes in the range of 5-15 Hz, the threshold value is linearly adjusted with the square root of the frequency, for example, when f=5 Hz, the threshold value is about 2.47 g, and when f=15 Hz, the threshold value is about 4.29 g, the frequency-related threshold value setting can more accurately judge the interference degree of vibration on the proximity switch at different frequencies, the target formula two sets the signal-to-noise ratio to be greater than or equal to 18 dB to ensure that the strength of the speed signal is sufficient, and avoid speed measurement errors caused by noise interference, and the three formulas are used in combination to quantitatively judge from the vibration intensity and the signal quality, so that the new proximity switch can stably output accurate signals in a vibrating environment, improve the speed measurement accuracy and reliability, and effectively solve the problem of abnormal speed measurement caused by vibration.

[0074] Embodiment 4

[0075] Based on the vibration frequency spectrum of the X, Y and Z axes of the slip ring monitored by the three-axis acceleration, the comprehensive installation reliability coefficient of the new proximity switch is calculated, including:

[0076] S331, based on the vibration frequency spectrum of the X, Y and Z axes of the slip ring monitored by the three-axis acceleration in each monitoring period, the vibration severity coefficient of the slip ring in the X, Y and Z axes is calculated;

[0077] S332, based on the vibration severity coefficient of the slip ring in the X, Y and Z axes, the comprehensive installation reliability coefficient of the new proximity switch is calculated;

[0078] The vibration severity coefficient of the slip ring in the X axis is:

[0079] Wherein, U x is the vibration severity coefficient of the slip ring in the X axis, a xi is the vibration acceleration root mean square value in the frequency band of 5-15 Hz calculated by the vibration frequency spectrum of the X axis of the slip ring in the i th monitoring period, e is a natural number, and the value is 2.71, and f0 is the resonance natural frequency of the slip ring;

[0080] The vibration severity coefficient of the slip ring in the Y axis is:

[0081] Wherein, U y is the vibration severity coefficient of the slip ring in the Y axis, a yi is the vibration acceleration root mean square value in the frequency band of 5-15 Hz calculated by the vibration frequency spectrum of the Y axis of the slip ring in the i th monitoring period;

[0082] The vibration severity coefficient of the slip ring in the Z axis is:

[0083] wherein, U z is the vibration severity coefficient of the slip ring on the Z axis, a zi is the vibration acceleration root mean square value in the 5-15Hz frequency band calculated by the vibration spectrum of the slip ring Z axis in the i th monitoring period;

[0084] The comprehensive installation reliability coefficient of the new proximity switch is:

[0085] wherein, W is the comprehensive installation reliability coefficient of the new proximity switch, and ω1, ω2 and ω3 are weight values of the vibration severity coefficient of the slip ring on the X axis, the vibration severity coefficient of the slip ring on the Y axis and the vibration severity coefficient of the slip ring on the Z axis respectively.

[0086] The working principle and beneficial effects of the above technical solution are: the vibration severity coefficient formula reflects the dispersion degree of the vibration acceleration of each monitoring period by introducing the standard deviation, the larger the standard deviation, the more unstable the vibration, the combination of n in the numerator and the mean value in the denominator can quantify the relative severity of the vibration, and the index part reflects the influence of resonance on the vibration severity through the absolute value ratio of the vibration frequency f and the deviation of the natural frequency f0, the smaller the deviation, the higher the resonance risk, and the smaller the coefficient value, the comprehensive installation reliability coefficient formula takes the reciprocal of the weighted sum of the vibration severity coefficients of each axis, which quantifies the influence of the vibration of each axis, and the weight value can be set according to the influence degree of each axis on the installation reliability, such as the Y axis radial vibration which has a great influence on the sensing gap, which can be given a higher weight. This calculation method comprehensively considers the stability of the vibration of each axis, the frequency resonance risk and the weight difference, accurately evaluates the installation reliability of the new proximity switch, provides a quantitative basis for judging whether it is necessary to adjust the installation or take vibration reduction measures, improves the accuracy of fault warning and the pertinence of installation and maintenance, and ensures the stable operation of the unit.

[0087] Embodiment 5

[0088] On the basis of embodiment 1, the step S2 further includes heat dissipation strengthening treatment.

[0089] The aluminum alloy heat dissipation fin group is additionally installed on the new proximity switch body, the heat-conducting silicone is smeared on the contact surface of the fin and the proximity switch, and the wedge-shaped damping block is additionally installed on the slip ring base.

[0090] The working principle and beneficial effects of the above technical solution are: the new proximity switch is subjected to heat dissipation strengthening treatment, the aluminum alloy heat dissipation fin group is additionally installed on the new proximity switch body, the heat-conducting silicone is smeared on the contact surface of the fin and the proximity switch, and the wedge-shaped damping block is additionally installed on the slip ring base, the heat dissipation area is increased by the heat dissipation fin, the heat conduction efficiency is enhanced by the heat-conducting silicone, and the vibration energy is absorbed by the wedge-shaped damping block, so that heat dissipation and vibration reduction are achieved.

[0091] The combination of aluminum alloy heat sink fins and thermally conductive silicone can quickly dissipate the heat generated by the new proximity switch during operation, reduce component temperature, avoid performance degradation and shortened life due to high temperature, and improve the operating stability and reliability of the proximity switch. The wedge-shaped damping block installed on the slip ring base can effectively absorb the vibration energy of the slip ring, reduce the impact of vibration on the installation position of the proximity switch, and further improve the speed measurement accuracy of the proximity switch in a vibrating environment. The combination of heat dissipation and vibration reduction measures not only ensures that the proximity switch operates within the normal temperature range, but also enhances its anti-vibration ability, doubly protecting the stability of the unit speed measurement system, reducing failures caused by temperature and vibration, extending the service life of the equipment, and reducing operation and maintenance costs.

[0092] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A solution to abnormal speed measurement caused by excessive slip ring vibration, characterized by: The following steps are involved: S1. Shut down the wind turbine generator set and cut off the power supply, and remove the original proximity switch at the slip ring; S2. Install the new proximity switch to the measurement position of the slip ring encoder; S3. Use a feeler gauge to calibrate the distance between the new proximity switch and the slip ring encoder disk, so that the distance between the new proximity switch and the slip ring encoder disk is adjusted to a preset range, and perform dynamic working condition calibration; S4. Tighten the mounting nut of the new proximity switch and mark the tightening mark on the nut.

2. A solution to abnormal speed measurement caused by excessive slip ring vibration according to claim 1, characterized in that: In step S3, the preset range between the new proximity switch and the slip ring encoder is 1.0-1.5 mm.

3. The solution to abnormal speed measurement caused by excessive slip ring vibration according to claim 1, characterized in that: Before step S2, the process also includes spraying an anti-vibration wear coating on the surface of the slip ring encoder; The anti-vibration wear coating is composed of tungsten carbide-cobalt metal ceramic composite, and the spraying thickness ranges from 50 to 100 μm.

4. The method according to claim 1, wherein: The steps of dynamic working condition calibration include: S31. Start the unit and increase the impeller speed to the range of 12 rpm to 48 rpm; S32. Synchronously monitor the vibration spectra of the slip ring along the X, Y, and Z axes using a three-axis accelerometer, and calculate the root mean square value of the vibration acceleration of any axis in the 5-15 Hz frequency band and the gain of the new proximity switch to achieve a signal-to-noise ratio based on the vibration spectra of the slip ring along the X, Y, and Z axes. S33. Calculate the comprehensive installation reliability coefficient of the new proximity switch based on the vibration spectrum of the slip ring X, Y, and Z axes monitored by three-axis acceleration; S34. Determine whether the root mean square value of the vibration acceleration of any axis in the 5-15 Hz frequency band satisfies target formula 1, whether the gain of the new proximity switch makes the signal-to-noise ratio satisfy target formula 2, and whether the comprehensive installation reliability coefficient of the new proximity switch is greater than the preset comprehensive installation reliability coefficient of the new proximity switch. If so, proceed to step S4; otherwise, repeat step S3.

5. The solution to abnormal speed measurement caused by excessive slip ring vibration according to claim 4 is characterized in that: The new proximity switch gain in the 5-15Hz frequency range for any axis makes the signal-to-noise ratio: Among them, SNR is the signal-to-noise ratio of the new proximity switch gain, S is the impeller speed signal amplitude, and N is the background noise amplitude; Target formula 1: Among them, a x 、a y and a z They represent the RMS values ​​of the vibration acceleration in the 5-15 Hz frequency range calculated from the vibration spectra of the slip ring along the X, Y, and Z axes, respectively. f is the vibration frequency of the slip ring. Target formula 2: SNR≥18dB.

6. The solution to abnormal speed measurement caused by excessive slip ring vibration according to claim 5, characterized in that: Based on the vibration spectrum of the slip ring X, Y, and Z axes monitored by three-axis acceleration, the comprehensive installation reliability coefficient of the new proximity switch is calculated, including: S331. Calculate the vibration severity coefficients of the slip ring in the X, Y, and Z axes based on the vibration spectra of the slip ring in the three-axis acceleration monitoring in each monitoring period; S332. Calculate the comprehensive installation reliability coefficient of the new proximity switch based on the vibration severity coefficients of the slip ring in the X, Y, and Z axes.

7. The solution to abnormal speed measurement caused by excessive slip ring vibration according to claim 6, characterized in that: Slip ring vibration severity coefficient in X axis: Among them, U x is the vibration severity coefficient of the slip ring in the X axis, a xi The root mean square value of the vibration acceleration in the 5-15 Hz frequency band calculated from the vibration spectrum of the slip ring X axis in the i-th monitoring period, e is a natural number with a value of 2.71, and f0 is the resonant natural frequency of the slip ring; Slip ring vibration severity coefficient in Y axis: Among them, U y is the vibration severity coefficient of the slip ring in the Y axis, a yi The root mean square value of the vibration acceleration in the 5-15 Hz frequency band calculated from the vibration spectrum of the slip ring Y axis during the i-th monitoring period; Slip ring vibration severity coefficient in Z axis: Among them, U z is the vibration severity coefficient of the slip ring in the Z axis, a zi The root mean square value of the vibration acceleration in the 5-15 Hz frequency band calculated from the vibration spectrum of the slip ring Z axis in the i-th monitoring period.

8. The solution to abnormal speed measurement caused by excessive slip ring vibration according to claim 7, characterized in that: Comprehensive installation reliability coefficient of the new proximity switch: Where W is the comprehensive installation reliability coefficient of the new proximity switch, ω1, ω2, and ω3 are the weight values ​​of the vibration severity coefficient of the slip ring on the X-axis, the vibration severity coefficient of the slip ring on the Y-axis, and the vibration severity coefficient of the slip ring on the Z-axis, respectively.

9. The solution to abnormal speed measurement caused by excessive slip ring vibration according to claim 1, characterized in that: Step S2 also includes heat dissipation enhancement processing; An aluminum alloy heat dissipation fin group is installed on the new proximity switch body, the contact surface between the fin and the proximity switch is coated with thermal conductive silicone, and a wedge-shaped damping block is installed on the slip ring base.

10. The solution to abnormal speed measurement caused by excessive slip ring vibration according to claim 1, characterized in that: The method also includes step S5: embedding a piezoelectric film sensor at the mounting bracket to collect axial force data of the new proximity switch in real time, and providing a maintenance hold prompt when the vibration impact force is detected to be greater than the preset vibration impact force for three consecutive times.

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