A method and system for monitoring abnormal vibration of high-voltage switchgear

Abstract

The present application relates to a kind of high-voltage switchgear vibration abnormal sound monitoring method and system, belong to high-voltage switchgear condition monitoring and evaluation field.The present application is first obtained the vibration, noise and voltage signal of high-voltage switchgear, then signal is analyzed to obtain frequency characteristic, finally three kinds of signals are compared and analyzed, when the frequency characteristic of noise signal contains the frequency characteristic of vibration signal, judge vibration abnormal sound in high-voltage switchgear inside, otherwise then judge vibration abnormal sound in high-voltage switchgear outside;When vibration abnormal sound is in high-voltage switchgear inside, again compare the frequency characteristic of electric field force and the frequency characteristic of vibration signal, judge vibration abnormal sound is because system voltage causes or because high-voltage switchgear itself exists defect causes.The present application combines vibration noise and voltage signal, judges whether high-voltage switchgear itself exists structural failure, not only can real-time monitoring high-voltage switchgear state, can also guarantee the safety of power grid system.

Description

Technical Field

[0001] This invention relates to a method and system for monitoring vibration and abnormal noise in high-voltage switchgear, belonging to the field of condition monitoring and evaluation of high-voltage switchgear. Background Technology

[0002] High-voltage switchgear, as a crucial component of the power system, has a vital impact on its operation due to its reliability. The vibration and noise levels of high-voltage switchgear reflect its basic operating status and directly influence how people judge its quality. Therefore, research on abnormal vibration and noise, and real-time analysis of their causes, are essential not only for real-time monitoring of the high-voltage switchgear's status but also for ensuring the safety of the power grid system, thus playing a significant role in the safety of high-voltage switchgear.

[0003] Currently, vibration analysis of high-voltage switchgear mainly focuses on the analysis of vibration signals. For example, Chinese patent application number CN201910293730.8 involves collecting vibration signals, analyzing and processing them to obtain the vibration signal spectrum, and then comparing the vibration signal spectrum with the signal spectrum during normal vibration to determine whether there are structural design defects. While this method can analyze abnormal noise through vibration signals, the cause of vibration noise could be the presence of harmonics in the voltage frequency or nonlinear vibration within the high-voltage switchgear itself. Analyzing only the characteristics of the vibration noise signal cannot definitively determine whether the high-voltage switchgear is malfunctioning, which can negatively impact the assessment results. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for monitoring vibration and abnormal noise in high-voltage switchgear, so as to solve the problem of errors in monitoring results caused by the single detection signal in the current process of monitoring vibration and abnormal noise in high-voltage switchgear.

[0005] To solve the above-mentioned technical problems, this invention provides a method for monitoring vibration and abnormal noise in high-voltage switchgear, which includes the following steps:

[0006] 1) Acquire vibration signals from high-voltage switchgear, noise signals from the surrounding environment, and voltage signals from high-voltage conductors;

[0007] 2) Perform time-frequency transformation on the obtained vibration signal, noise signal, and voltage signal to obtain the frequency characteristics of each signal;

[0008] 3) Obtain the typical frequency of each signal through the frequency characteristics of each signal, compare the frequency characteristics of the vibration signal with the frequency characteristics of the noise signal, if the typical frequency of the vibration signal is consistent with the typical frequency of the noise signal or the typical frequency of the noise signal is within the frequency range of the vibration signal, then the vibration noise is inside the high-voltage switchgear; otherwise, the vibration noise is outside the high-voltage switchgear. The typical frequency refers to the frequency with the higher amplitude in the signal.

[0009] 4) When the vibration and abnormal noise are inside the high-voltage switchgear, obtain the frequency characteristics of the electric field force based on the frequency characteristics of the voltage signal, and compare the frequency characteristics of the vibration signal with the frequency characteristics of the electric field force. If the typical frequency of the electric field force signal includes the typical frequency of the vibration signal, then the vibration and abnormal noise are caused by the system voltage. Otherwise, the vibration and abnormal noise are caused by defects in the high-voltage switchgear itself.

[0010] This invention first acquires vibration, noise, and voltage signals from high-voltage switchgear using sensors. Then, it performs spectral analysis on the signals to obtain their frequency characteristics. Finally, by comparing the frequency characteristics of the three signals, it defines and identifies abnormal vibrations and noises. This invention achieves quantitative analysis of high-voltage switchgear, quantitative analysis of abnormal vibrations and noises, extraction of frequency domain features from vibration, noise, and voltage signals, and, combined with the vibration and noise signals, defines and identifies the types of abnormal vibrations and noises, determining whether there are structural faults in the high-voltage switchgear itself. This not only enables real-time monitoring of the high-voltage switchgear's status but also ensures the safety of the power grid system.

[0011] Furthermore, the vibration signal in step 1) is obtained by setting a vibration acceleration sensor on the surface of the high-voltage switch cylinder.

[0012] Furthermore, the noise signal in step 1) is obtained by setting an acoustic sensor in the ambient air where the high-voltage switchgear is located.

[0013] By measuring vibration acceleration signals on the surface of the high-voltage switchgear cylinder and noise signals in the external ambient air domain, and by jointly measuring the vibration of the equipment surface and the noise in the environment, a comparative study of vibration and noise signals can be achieved.

[0014] Furthermore, the voltage signal in step 1) is obtained by setting a voltage sensor inside the high-voltage switch housing.

[0015] This invention embeds a sensor in the high-voltage switch cylinder to monitor the voltage waveform of the central conductor relative to the cylinder ground potential, thereby obtaining the true signal of the vibration excitation source.

[0016] Furthermore, the time-frequency transformation in step 2) uses the Fast Fourier Transform.

[0017] Fast Fourier analysis can process large amounts of data in a short time and can quickly and accurately obtain the frequency characteristics of a signal.

[0018] Furthermore, in step 4), when determining the frequency characteristics of the electric field force, the frequency components present in the voltage signal are determined separately.

[0019] The frequency of the voltage signal has a definite relationship with the frequency of the electric field force. By analyzing the frequency characteristics of the electric field force, it can be determined whether the vibration is caused by high harmonics in the power system.

[0020] This invention also provides a vibration and noise monitoring system for high-voltage switchgear, including a signal acquisition module and a signal processing module. The signal acquisition module acquires vibration signals, noise signals, and voltage signals from the high-voltage switchgear, while the signal processing module analyzes and compares the acquired signals. If the typical frequency of the vibration signal matches the typical frequency of the noise signal, or if the typical frequencies of the noise signal are both within the typical frequency range of the vibration signal, the vibration and noise are determined to be inside the high-voltage switchgear; otherwise, the vibration and noise are determined to be outside the high-voltage switchgear. When the vibration and noise are inside the high-voltage switchgear, the frequency characteristics of the electric field force are compared with the frequency characteristics of the vibration signal. If the typical frequency of the electric field force signal includes the typical frequency of the vibration signal, the vibration and noise are determined to be caused by the system voltage; otherwise, the vibration and noise are determined to be caused by a defect in the high-voltage switchgear itself. The typical frequency refers to the frequency with the highest amplitude in the signal.

[0021] This invention first acquires vibration, noise, and voltage signals from high-voltage switchgear using sensors. Then, it performs spectral analysis on the signals to obtain their frequency characteristics. Finally, by comparing the frequency characteristics of the three signals, it defines and identifies abnormal vibrations and noises. This invention achieves quantitative analysis of high-voltage switchgear, quantitative analysis of abnormal vibrations and noises, extraction of frequency domain features from vibration, noise, and voltage signals, and, combined with the vibration and noise signals, defines and identifies the types of abnormal vibrations and noises, determining whether there are structural faults in the high-voltage switchgear itself. This not only enables real-time monitoring of the high-voltage switchgear's status but also ensures the safety of the power grid system.

[0022] Furthermore, the time-frequency transformation uses the Fast Fourier Transform.

[0023] Fast Fourier analysis can process large amounts of data in a short time and can quickly and accurately obtain the frequency characteristics of a signal.

[0024] Furthermore, the frequency characteristics of the electric field force are calculated using a formula based on the frequency characteristics of the voltage signal.

[0025] The frequency of the voltage signal has a definite relationship with the frequency of the electric field force. By analyzing the frequency characteristics of the electric field force, it can be determined whether the vibration is caused by high harmonics in the power system.

[0026] Furthermore, the signal acquisition module includes a vibration acceleration sensor, an acoustic sensor, and a voltage sensor. The vibration acceleration sensor is used to acquire the vibration signal of the high-voltage switchgear, the acoustic sensor is used to acquire the noise signal of the environment where the high-voltage switchgear is located, and the voltage sensor is used to acquire the voltage signal inside the high-voltage switchgear housing.

[0027] This invention embeds a sensor in the high-voltage switch cylinder to monitor the voltage waveform of the central conductor relative to the cylinder ground potential, thereby obtaining the true signal of the vibration excitation source. Attached Figure Description

[0028] Figure 1 This is a diagram of the vibration and abnormal noise monitoring system for high-voltage switchgear of the present invention;

[0029] Figure 2 This is the logic diagram for collecting, analyzing, and judging vibration and abnormal noise in high-voltage switchgear according to the present invention. Detailed Implementation

[0030] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0031] Example of a vibration and noise monitoring system for high-voltage switchgear

[0032] This invention comprises a signal acquisition module and a signal processing module. First, the signal acquisition module acquires vibration, noise, and voltage signals from the high-voltage switchgear. Then, the signal processing module performs spectral analysis on the acquired signals to obtain their frequency characteristics. Finally, the frequency characteristics are compared and analyzed. When the typical frequency of the vibration signal matches the typical frequency of the noise signal, or when the typical frequency of the noise signal falls within the typical frequency range of the vibration signal, the abnormal vibration / noise is determined to be inside the high-voltage switchgear; otherwise, it is determined to be outside the high-voltage switchgear. When the abnormal vibration / noise is inside the high-voltage switchgear, the frequency characteristics of the electric field force are compared with those of the vibration signal. If the typical frequency of the electric field force includes the typical frequency of the vibration signal, the abnormal vibration / noise is determined to be caused by the system voltage; otherwise, it is determined to be caused by a defect in the high-voltage switchgear itself. Specific examples will be used to illustrate this further.

[0033] Vibration and noise in high-voltage switchgear are two physical quantities representing the same problem; noise is the result of vibration waves radiating from the equipment into the air. In this embodiment, vibration acceleration signals are measured on the surface of the high-voltage switchgear cylinder, and noise signals are measured in the external ambient air domain. The vibration on the equipment surface and the noise in the environment are measured jointly, and the vibration and noise signals are compared and studied.

[0034] The central conductor of the high-voltage switch has capacitive properties with respect to the cylinder. The plates on both sides of the capacitor are subjected to Coulomb forces between the charges, resulting in mechanical deformation. The periodic change in the voltage of the central conductor relative to ground leads to periodic vibration. In this embodiment, a sensor is embedded in the cylinder of the high-voltage switch to monitor the voltage waveform of the central conductor relative to the cylinder's ground potential, thereby obtaining the true signal of the vibration excitation source.

[0035] Specifically, a high-voltage switchgear vibration and noise monitoring system, such as Figure 1 As shown, the signal acquisition module includes a vibration acceleration sensor S1, an acoustic sensor S2, and a voltage sensor S3. The vibration acceleration sensor S1 is used to obtain vibration acceleration signals by being placed on the surface of the high-voltage switch cylinder. The acoustic sensor S2 is used to obtain noise signals in the ambient air by being placed in the ambient air. The voltage sensor S3 is used to be placed inside the high-voltage switch housing. The high-voltage conductor forms the two plates of a capacitor. There is leakage current between the capacitors. The sensor integrates the leakage current with the fixed resistor to generate a voltage signal, which is the output signal of the sensor.

[0036] The signal processing module performs time-frequency transformation on the obtained signal. This embodiment uses Fast Fourier Transform, but other transformation methods, such as Fourier Transform, can also be used. The signal processing module performs spectral analysis on the transformed signal, analyzes the frequency characteristics of the three sensor signals, and then performs comparative analysis. First, the frequency with higher amplitude is selected from the noise signal and vibration signal as the typical frequency of each signal. When the typical frequency of the noise signal is consistent with the typical frequency of the vibration signal, that is, the frequency with higher amplitude in the noise signal is the same as or close to the frequency with higher amplitude in the vibration signal, or the typical frequencies in the noise signal are all reflected in the vibration signal, that is, the frequency components in the noise are less than the frequency components in the vibration, or the frequency components in the noise are equal to the frequency components in the vibration, it indicates that the noise is radiated from the product vibration. For example, if the typical frequency of the noise signal is 30Hz, and the corresponding vibration signal frequency range is 40-100Hz, then the typical frequency of this noise signal is not reflected in the vibration signal. In this case, it is determined that the noise is radiated from the high-voltage switch housing into the environment, that is, the vibration of the high-voltage switch itself causes the noise. When the typical frequency of the noise signal is inconsistent with the typical frequency of the vibration signal, it is determined that the abnormal vibration is outside the high-voltage switchgear.

[0037] The system voltage generates an electric field force, which causes relative motion between the high-voltage conductor and the shell. The frequency of the voltage signal and the frequency of the electric field force have a definite relationship. If the voltage is a single-frequency signal, the frequency of the electric force is twice the voltage frequency. If the voltage contains multiple frequencies, the frequency of the electric force is more varied and complex, and can be calculated using formulas.

[0038] When determining the frequency characteristics of the electric field force, it is determined based on the number of frequency components present in the voltage signal. When the voltage has only one frequency component, the formula for calculating the vibration force between the capacitor plates is:

[0039]

[0040] In the formula, F is the electric field force, ε is the dielectric constant, U is the voltage, and d is the distance between the electrodes.

[0041] As can be seen from the above formula, the electrostatic force between the capacitor plates is twice the power supply frequency.

[0042] When the voltage has two frequency components, the vibrational force between the capacitor plates is as follows:

[0043]

[0044] In the formula, K is a general coefficient.

[0045] When the voltage has three frequency components, the vibrational force between the capacitor plates is as follows:

[0046]

[0047] When different frequency components in a power supply superimpose, they will form vibrational forces of multiple frequencies. When multiple frequency components exist, the calculation of the vibrational force between capacitor plates can be deduced in the same way.

[0048] When the typical frequency of the noise signal matches the typical frequency of the vibration signal, the frequency characteristics of the vibration signal are then compared with those of the electric field force. If the typical frequency of the electric field force includes the typical frequency of the vibration signal (i.e., the higher amplitude frequencies in the vibration signal also correspond to higher amplitude frequencies in the electric field force signal), then the vibration of the casing is determined to be caused by high-frequency harmonics in the power system. Conversely, if the vibration signal has many typical frequencies that the typical frequency of the electric field force cannot fully encompass, then the abnormal vibration is determined to be caused by a defect in the high-voltage switchgear itself. The judgment logic of this monitoring system is as follows: Figure 2 As shown.

[0049] Examples of vibration and abnormal noise monitoring methods for high-voltage switchgear.

[0050] This invention first acquires vibration, noise, and voltage signals from high-voltage switchgear using sensors. Then, it performs spectral analysis on the acquired signals to obtain the frequency characteristics of the three signals. Finally, it compares and analyzes the three signals. The frequency characteristics of the vibration signal are compared with those of the noise signal. If the typical frequency of the vibration signal matches the typical frequency of the noise signal, or if the typical frequencies of the noise signal are both within the typical frequency range of the vibration signal, the abnormal vibration / noise is determined to be inside the high-voltage switchgear; otherwise, it is determined to be outside the high-voltage switchgear. When the abnormal vibration / noise is inside the high-voltage switchgear, the frequency of the electric field force is obtained based on the frequency of the voltage signal. The frequency characteristics of the electric field force are then compared with those of the vibration signal. If the typical frequency of the electric field force includes the typical frequency of the vibration signal, the abnormal vibration / noise is caused by the system voltage; otherwise, it is caused by a defect in the high-voltage switchgear itself. The specific implementation of this method has been described in detail in the embodiments of the high-voltage switchgear vibration / noise acquisition and analysis system, and will not be repeated here.

Claims

1. A method for monitoring vibration and abnormal noise in high-voltage switchgear, characterized in that, The method includes the following steps: 1) Acquire vibration signals from high-voltage switchgear, noise signals from the surrounding environment, and voltage signals from high-voltage conductors; 2) Perform time-frequency transformation on the obtained vibration signal, noise signal, and voltage signal to obtain the frequency characteristics of each signal; 3) Obtain the typical frequency of each signal through the frequency characteristics of each signal, compare the frequency characteristics of the vibration signal with the frequency characteristics of the noise signal, if the typical frequency of the vibration signal is consistent with the typical frequency of the noise signal or the typical frequency of the noise signal is within the frequency range of the vibration signal, then the vibration noise is inside the high-voltage switchgear; otherwise, the vibration noise is outside the high-voltage switchgear. The typical frequency refers to the frequency with the higher amplitude in the signal. 4) When the vibration and abnormal noise are inside the high-voltage switchgear, obtain the frequency characteristics of the electric field force based on the frequency characteristics of the voltage signal, and compare the frequency characteristics of the vibration signal with the frequency characteristics of the electric field force. If the typical frequency of the electric field force signal includes the typical frequency of the vibration signal, then the vibration and abnormal noise are caused by the system voltage. Otherwise, the vibration and abnormal noise are caused by defects in the high-voltage switchgear itself.

2. The method for monitoring vibration and abnormal noise in high-voltage switchgear according to claim 1, characterized in that, The vibration signal in step 1) is obtained by setting a vibration acceleration sensor on the surface of the high-voltage switch cylinder.

3. The method for monitoring vibration and abnormal noise in high-voltage switchgear according to claim 1, characterized in that, The noise signal in step 1) is obtained by setting an acoustic sensor in the ambient air where the high-voltage switchgear is located.

4. The method for monitoring vibration and abnormal noise in high-voltage switchgear according to claim 1, characterized in that, The voltage signal in step 1) is obtained by installing a voltage sensor inside the high-voltage switch housing.

5. The method for monitoring vibration and abnormal noise in high-voltage switchgear according to any one of claims 1-4, characterized in that, The time-frequency transformation uses the Fast Fourier Transform.

6. The method for monitoring vibration and abnormal noise in high-voltage switchgear according to claim 1, characterized in that, In step 4), when determining the frequency characteristics of the electric field force, the frequency components in the voltage signal are determined separately.

7. A vibration and abnormal noise monitoring system for high-voltage switchgear, comprising a signal acquisition module and a signal processing module, characterized in that, The signal acquisition module is used to acquire vibration, noise, and voltage signals from the high-voltage switchgear. The signal processing module is used to analyze and compare the acquired signals. When the typical frequency of the vibration signal is the same as the typical frequency of the noise signal, or when the typical frequency of the noise signal is within the typical frequency range of the vibration signal, it is determined that the vibration or noise is inside the high-voltage switchgear; otherwise, it is determined that the vibration or noise is outside the high-voltage switchgear. When the vibration or noise is inside the high-voltage switchgear, the frequency characteristics of the electric field force are compared with the frequency characteristics of the vibration signal. If the typical frequency of the electric field force signal includes the typical frequency of the vibration signal, it is determined that the vibration or noise is caused by the system voltage; otherwise, it is determined that the vibration or noise is caused by a defect in the high-voltage switchgear itself. The typical frequency refers to the frequency with the higher amplitude in the signal.

8. The high-voltage switchgear vibration and abnormal noise monitoring system according to claim 7, characterized in that, The time-frequency transformation uses the Fast Fourier Transform.

9. The high-voltage switchgear vibration and abnormal noise monitoring system according to claim 7, characterized in that, The frequency characteristics of the electric field force are calculated using a formula based on the frequency characteristics of the voltage signal.

10. The high-voltage switchgear vibration and abnormal noise monitoring system according to claim 7, characterized in that, The signal acquisition module includes a vibration acceleration sensor, an acoustic sensor, and a voltage sensor. The vibration acceleration sensor is used to acquire the vibration signal of the high-voltage switchgear, the acoustic sensor is used to acquire the noise signal of the environment in which the high-voltage switchgear is located, and the voltage sensor is used to acquire the voltage signal inside the high-voltage switchgear housing.

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