A GIS resonance judgment method and system based on vibration characteristic values

Abstract

The application provides a GIS resonance judgment method and system based on vibration characteristic values, and belongs to the technical field of electric power operation and maintenance. The method comprises the following steps: vibration measuring points are arranged on the surface of a GIS device shell, a vibration sensor is used to obtain a time-domain vibration signal y m (t) at the measuring points, m represents the measuring point serial number; the time-domain vibration signal y m (t) is preprocessed to obtain a preprocessed vibration signal y 1m (t); a GIS vibration frequency spectrum signal y 1m (f) is extracted from the vibration signal y 1m (t) by using FFT fast Fourier decomposition calculation; vibration characteristic parameters are extracted based on the GIS vibration frequency spectrum signal y 1m (f), and a state characteristic parameter is further calculated based on reference characteristic parameters; the characteristic parameters comprise a main frequency energy ratio and total vibration entropy; the state characteristic parameter comprises a main frequency f main‑m , an average vibration entropy change amount ΔH and an average main frequency energy ratio change amount Δp main ; whether the mechanical state of the GIS device is resonance is judged according to the state characteristic parameter and in combination with a preset evaluation standard.

Description

Technical Field

[0001] This invention relates to the field of power operation and maintenance technology, and in particular to a GIS resonance judgment method and system based on vibration characteristic values. Background Technology

[0002] Gas-insulated switchgear (GIS) is a widely used high-voltage switchgear in power transmission networks. Compared with traditional open-type equipment, GIS has advantages such as smaller footprint, higher reliability, and stronger environmental compatibility, and is therefore widely used in important loads and hub substations. The structure of GIS approximates a simply supported beam, making it susceptible to mechanical resonance due to complex harmonics in the system. This can result in abnormal noise or, in severe cases, structural damage, seriously impacting the safe operation of the power grid. Currently, the evaluation of the resonance state of GIS equipment mainly relies on the judgment of operators based on personal experience during regular inspections. This method is highly dependent on operator experience, subjective, and difficult to implement. Therefore, there is an urgent need to develop a method that can objectively and accurately determine whether a GIS is resonating. Summary of the Invention

[0003] In view of this, the present invention provides a GIS resonance judgment method and system based on vibration characteristic values, which is used to objectively and accurately evaluate the mechanical condition of GIS equipment, which helps to extend the service life of GIS equipment and improve the safety of power operation and maintenance.

[0004] The technical solution adopted by the embodiments of the present invention to solve its technical problem is as follows:

[0005] A method for determining GIS resonance based on vibration characteristic values, comprising:

[0006] Step S1: Set vibration measurement points on the surface of the GIS equipment casing, and use vibration sensors to obtain time-domain vibration signals y at the measurement points. m (t), where m represents the vibration measurement point number;

[0007] Step S2, for the time-domain vibration signal y m (t) Preprocessing to obtain the preprocessed vibration signal y 1m (t);

[0008] Step S3: Calculate the vibration signal y using Fast Fourier Transform (FFT). 1m (t) Extract the GIS vibration spectrum signal y 1m (f);

[0009] Step S4, based on the GIS vibration spectrum signal y 1m(f) extracting the vibration characteristic parameters, and further calculating the state characteristic parameters based on the reference characteristic parameters; the characteristic parameters include the main frequency energy ratio and the total vibration entropy; the state characteristic parameters include the main frequency f main-m , the average vibration entropy change ΔH and the average main frequency energy ratio change Δp main ;

[0010] Step S5, evaluating the mechanical state of the GIS device according to the state characteristic parameters and in combination with preset evaluation criteria;

[0011] The step S5 is specifically implemented as:

[0012] Each of the main frequencies f main-m is 100 Hz, and the GIS vibration spectrum signal y 1m (f) there is no obvious vibration at other frequencies, and ΔH ∈ [-5%, 5%], Δp main ∈ [-5%, 5%], it is determined that the mechanical state of the GIS device is normal; the other frequencies refer to frequencies other than 100 Hz, and the obvious vibration refers to vibration with an amplitude exceeding 25% of the vibration at 100 Hz;

[0013] Each of the main frequencies f main-m is 100 Hz, and the GIS vibration spectrum signal y 1m (f) there is obvious vibration at other frequencies, and ΔH ∈ [0%, 5%], Δp main ∈ [-5%, 0%], it is determined that the mechanical state of the GIS device is mild resonance;

[0014] Each of the main frequencies f main-m is 100 Hz, and the GIS vibration spectrum signal y 1m (f) there is obvious vibration at other frequencies, and ΔH ∈ [5%, 10%], Δp main ∈ [-10%, -5%], it is determined that the mechanical state of the GIS device is moderate resonance;

[0015] Each of the main frequencies f main-m is 100 Hz, and the GIS vibration spectrum signal y 1m (f) there is obvious vibration at other frequencies, and ΔH ∈ [10%, 15%], Δp main ∈ [-15%, -10%], it is determined that the mechanical state of the GIS device is severe resonance;

[0016] In any of the cases of ΔH > 15% or Δp main < -15%, it is determined that the mechanical state of the GIS device is serious resonance;

[0017] Each of the main frequencies fmain-m for other frequencies, and satisfy ΔH∈[-5%,5%], Δp main for other frequencies, and satisfy ΔH∈[-5%,5%], Δp

[0018] Preferably, the preprocessing includes filtering, denoising and normalization processing.

[0019] Preferably, the reference characteristic parameters include reference total vibration entropy H (ref) and reference main frequency energy ratio p main(ref) , which are characteristic parameters of the GIS device in historical health state or characteristic parameters of the GIS device of the same structure in health state; when the GIS device has characteristic parameters in historical health state, the characteristic parameters in historical health state are preferentially selected as the reference characteristic parameters; when the GIS device does not have characteristic parameters in historical health state, the characteristic parameters of the GIS device of the same structure in health state are selected as the reference characteristic parameters.

[0020] Preferably, step S4 is based on the GIS vibration frequency spectrum signal y 1m (f) extracting vibration characteristic parameters includes:

[0021] The calculation process of the main frequency f main-m is as follows:

[0022] Using the GIS vibration frequency spectrum signal y 1m (f) extracting effective values A i corresponding to I frequencies of 50iHz (i=1, 2, …, I) main-m , and selecting the frequency with the maximum effective value as the main frequency f main ;

[0023] The calculation process of the total vibration entropy H is as follows:

[0024]

[0025] wherein, P is total power; H takes a value in the interval [0, 1];

[0026] The calculation process of the main frequency energy ratio p main is as follows:

[0027]

[0028] wherein, max(A i ) represents the maximum effective value, i.e. the effective value of the main frequency f main-m .

[0029] Preferably, in step S4, the expression of the state characteristic parameter is as follows:

[0030]

[0031] H m represents the vibration entropy of the signal collected at the vibration measuring point m, represents the main frequency energy ratio of the signal collected at the vibration measuring point; M represents the total number of vibration measuring points.

[0032] Preferably, the main frequencies f main-m are generally consistent;

[0033] When the main frequencies f main-m are not all consistent, the value with the highest main frequency value repetition rate is selected as the representative value to execute step S5;

[0034] When the main frequencies f main-m are all inconsistent, it is considered that the GIS device currently has a fault and needs to be stopped for inspection.

[0035] Preferably, the measuring points are located on the surface of the bus cylinder of the GIS device, and there are 5 points in total, wherein, the 1st and 5th points are located at the left end and right end of the bus cylinder respectively, the 3rd point is located at the middle part of the bus cylinder, the 2nd point is located at the midpoint of the line connecting the 1st and 3rd points, and the 4th point is located at the midpoint of the line connecting the 3rd and 5th points.

[0036] The application also provides a GIS resonance judgment system based on vibration characteristic values, comprising a group of vibration sensors and an upper computer; the vibration sensors are arranged at vibration measuring points on the surface of the shell of the GIS device, for collecting signals and sending the signals to the upper computer; the upper computer is used for receiving the signals transmitted by the vibration sensors and executing the above-mentioned method.

[0037] From the above technical solution, it can be known that the GIS resonance judgment method and system based on vibration characteristic values provided by the embodiments of the application. Firstly, vibration measuring points are arranged on the surface of the shell of the GIS device, and time domain vibration signals y m (t) are obtained at the vibration measuring points by using vibration sensors; the time domain vibration signals y m (t) are preprocessed to obtain preprocessed vibration signals y 1m (t); the GIS vibration frequency spectrum signals y 1m (f) are extracted from the vibration signals y 1m (t) by using FFT fast Fourier decomposition calculation; vibration characteristic parameters are extracted based on the GIS vibration frequency spectrum signals y 1m (f), and state characteristic parameters are further calculated based on reference characteristic parameters; the characteristic parameters include the main frequency energy ratio and the total vibration entropy; the state characteristic parameters include the main frequency f main-m , the average vibration entropy change amount ΔH and the average main frequency energy ratio change amount Δp mainAccording to the state characteristic parameter, and in combination with the preset evaluation standard, the mechanical state of the GIS device is evaluated. Compared with the method in the prior art in which an operating personnel observes and judges according to personal experience, the evaluation of the resonance state of the GIS in the present application is more objective and accurate, can provide decision support for preventive maintenance and fault handling of the GIS device, helps to prolong the service life of the GIS device, and improves the safety of power operation. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 A flowchart of a GIS resonance judgment method based on a vibration characteristic value according to the present application. DETAILED DESCRIPTION

[0039] The technical solutions and technical effects of the present application are further described in detail below in combination with the drawings of the present application.

[0040] As shown in Figure 1 , the present application provides a GIS resonance judgment method based on a vibration characteristic value, and the implementation steps include:

[0041] Step S1, signal acquisition: vibration measuring points are arranged on the surface of the shell of the GIS device, and a vibration sensor is used to obtain a time-domain vibration signal y m (t) at the measuring point, and m represents the measuring point serial number;

[0042] Step S2, vibration signal processing: the collected time-domain vibration signal y m (t) is preprocessed to obtain a preprocessed vibration signal y 1m (t); here, the preprocessing refers to preprocessing of filtering, denoising and normalization on the original vibration signal y m (t), and m represents the measuring point serial number;

[0043] Step S3, Fourier decomposition and vibration spectrum diagram extraction: FFT fast Fourier decomposition calculation is used to extract a GIS vibration spectrum signal y 1m (f) from the vibration signal y 1m (t);

[0044] Step S4, vibration characteristic parameter extraction: vibration characteristic parameters are extracted based on the GIS vibration spectrum signal y 1m (f), and a state characteristic parameter is further calculated based on a reference characteristic parameter; the characteristic parameters include a main frequency energy ratio and total vibration entropy; the state characteristic parameters include a main frequency f main-m , an average vibration entropy change amount ΔH and an average main frequency energy ratio change amount Δp main ;

[0045] Step S5, state evaluation: according to the state characteristic parameters, and combining with the preset evaluation standard, the mechanical state of the GIS device is evaluated;

[0046] Preferably, the reference characteristic parameters include a reference total vibration entropy H (ref) and a reference main frequency energy ratio p main(ref) , which are characteristic parameters of the GIS device in a historical healthy state or characteristic parameters of a GIS device of the same structure in a healthy state; when the GIS device has characteristic parameters in a historical healthy state, the characteristic parameters in the historical healthy state are preferentially selected as the reference characteristic parameters; when the GIS device does not have characteristic parameters in a historical healthy state, for example, the GIS device is a newly installed device, when it is detected for the first time, the characteristic parameters of the GIS device of the same structure in a healthy state are selected as the reference characteristic parameters.

[0047] Step S4 is based on the GIS vibration frequency spectrum signal y 1m (f) extracting the vibration characteristic parameters includes:

[0048] The main frequency f main-m is calculated as follows:

[0049] The GIS vibration frequency spectrum signal y 1m (f) extracts the effective value A i corresponding to the I frequencies of 50iHz (i=1, 2,..., I); the frequency with the maximum effective value is selected as the main frequency f main-m ; as an embodiment, I=40, the main frequency f main-m is generally 100Hz;

[0050] The calculation process of the total vibration entropy H is as follows:

[0051]

[0052]

[0053] Wherein, P is the total power; the value range of H is [0, 1]; H is close to 0, which indicates that the vibration signal energy is concentrated; H is close to 1, which indicates that the vibration signal energy is dispersed;

[0054] The calculation process of the main frequency energy ratio p main is as follows:

[0055]

[0056] Wherein, max(A i ) represents the maximum effective value, i.e. the effective value of the main frequency f main-m .

[0057] Preferably, in step S4, the expression of the state characteristic parameters is:

[0058]

[0059] wherein H m represents the vibration entropy of the signal collected at the measuring point m, represents the dominant frequency energy ratio of the signal collected at the measuring point; M represents the total number of measuring points.

[0060] The step S5 is specifically implemented as:

[0061] Each dominant frequency f main-m is 100 Hz, and the GIS vibration spectrum signal y 1m (f) there is no obvious vibration at other frequencies, and ΔH ∈ [-5%, 5%], Δp main ∈ [-5%, 5%], it is determined that the mechanical state of the GIS device is normal; the other frequencies refer to frequencies other than 100 Hz, and the obvious vibration refers to vibration with an amplitude exceeding 25% of the vibration at 100 Hz;

[0062] Each dominant frequency f main-m is 100 Hz, and the GIS vibration spectrum signal y 1m (f) there is obvious vibration at other frequencies, and ΔH ∈ [0%, 5%], Δp main ∈ [-5%, 0%], it is determined that the mechanical state of the GIS device is mild resonance;

[0063] Each dominant frequency f main-m is 100 Hz, and the GIS vibration spectrum signal y 1m (f) there is obvious vibration at other frequencies, and ΔH ∈ [5%, 10%], Δp main ∈ [-10%, -5%], it is determined that the mechanical state of the GIS device is moderate resonance;

[0064] Each dominant frequency f main-m is 100 Hz, and the GIS vibration spectrum signal y 1m (f) there is obvious vibration at other frequencies, and ΔH ∈ [10%, 15%], Δp main ∈ [-15%, -10%], it is determined that the mechanical state of the GIS device is severe resonance;

[0065] In any of the following cases: ΔH > 15% or Δp main < -15%, it is determined that the mechanical state of the GIS device is serious resonance;

[0066] Each dominant frequency f main-m is other frequencies, and ΔH ∈ [-5%, 5%], Δp main∈ [-5%, 5%], determining that the mechanical state of the GIS device is other conditions, and the change reason needs to be immediately studied.

[0067] The main frequency f of the m points main-m Generally consistent;

[0068] When the main frequency f of the m points main-m When not all, select the value with the highest frequency value repetition rate as the representative value to execute step S5;

[0069] When the main frequency f of the m points main-m When all, it is considered that the current GIS device has a major fault and needs to be stopped for inspection.

[0070] The application also provides a GIS resonance judgment system based on vibration characteristic values, comprising a group of vibration sensors and an upper computer; the vibration sensors are arranged at vibration measuring points on the surface of the GIS device shell, used for collecting signals and sending them to the upper computer; the upper computer is used for receiving signals transmitted by each vibration sensor, and executing Figure 1 The method.

[0071] An embodiment of system installation is provided below, three vibration measuring points are uniformly arranged at the surface of the GIS shell 1, two vibration measuring points are arranged at the edge surface of the insulating basin 2, the measuring points are located on the surface of the busbar cylinder of the GIS device, and there are five in total, wherein, the first and fifth points are located at the left and right ends of the busbar cylinder respectively, the third point is located at the middle part of the busbar cylinder, the second point is located at the midpoint of the line connecting the first and third points, and the fourth point is located at the midpoint of the line connecting the third and fifth points.

[0072] The above GIS resonance judgment method based on vibration characteristic values collects original vibration signals by using vibration sensors on the surface of the GIS shell to be measured, and extracts the main frequency, main frequency energy ratio and total vibration entropy of the GIS device through a series of pretreatment and FFT analysis, further compares them with reference characteristic parameters, obtains state characteristic parameters for evaluating the mechanical state of the GIS, the average vibration entropy change amount and the average main frequency energy ratio change amount, and then evaluates the mechanical state of the GIS according to the evaluation standard; compared with the method in the prior art in which the operating personnel observes and judges according to personal experience, the evaluation of the resonance state of the GIS in the application is more objective and accurate, can provide decision support for the preventive maintenance and fault handling of the GIS device, helps to prolong the service life of the GIS device and improve the safety of power operation.

[0073] The above only discloses the preferred embodiments of the application, and of course cannot limit the scope of the application, and those skilled in the art can understand that all or part of the above-mentioned embodiments can be implemented, and equivalent changes made according to the claims of the application still belong to the scope covered by the application.

Claims

1. A GIS resonance judgment method based on vibration characteristic values, characterized in that, Comprise: Step S1, setting a vibration measuring point on the surface of the GIS device shell, using a vibration sensor to obtain a time-domain vibration signal y m (t), m represents the measuring point sequence number; Step S2, obtaining a time-domain vibration signal y m (t) by preprocessing; and 1m (t); Step S3, using FFT fast Fourier decomposition calculation, from the vibration signal y 1m (t) extract the GIS vibration spectrum signal y 1m (f); Step S4, calculating the state characteristic parameter based on the GIS vibration frequency spectrum signal y 1m (f) extracting vibration characteristic parameters, and further calculating a state characteristic parameter based on reference characteristic parameters; the characteristic parameters include main frequency energy ratio and total vibration entropy; the state characteristic parameter includes main frequency f main-m , average vibration entropy change amount ΔH and average main frequency energy ratio change amount Δp main ; Step S5, according to the state characteristic parameter, and combine the preset evaluation standard, the mechanical state of GIS equipment is evaluated; The step S5 is specifically implemented as: each of the main frequencies f main-m is 100 Hz, the GIS vibration frequency spectrum signal y 1m (f) no significant vibration exists at other frequencies, and ΔH∈[-5%, 5%], Δp main ∈[-5%, 5%], it is determined that the mechanical state of the GIS device is normal; the other frequencies refer to frequencies other than 100 Hz, and the significant vibration refers to vibration with an amplitude exceeding 25% of the vibration at 100 Hz. each of the main frequencies f main-m is 100 Hz, the GIS vibration frequency spectrum signal y 1m (f) there is obvious vibration at other frequencies, and ΔH∈[0%, 5%], Δp main ∈[-5%, 0%], it is determined that the mechanical state of the GIS device is mild resonance; each of the main frequencies f main-m is 100 Hz, the GIS vibration frequency spectrum signal y 1m (f) there is obvious vibration at other frequencies, and ΔH ∈ [5%, 10%], Δp main ∈ [-10%, -5%], it is determined that the mechanical state of the GIS device is moderate resonance; each of the main frequencies f main-m is 100 Hz, the GIS vibration frequency spectrum signal y 1m (f) there is obvious vibration at other frequencies, and ΔH∈[10%, 15%], Δp main ∈[-15%, -10%], it is determined that the mechanical state of the GIS device is severe resonance; satisfying ΔH > 15% or Δp main In any of these cases, the mechanical state of the GIS equipment is determined to be a severe resonance. Each of the main frequencies f main-m for other frequencies, and satisfy ΔH ∈ [-5%, 5%], Δp main ∈ [-5%, 5%], it is determined that the mechanical state of the GIS device is other conditions, and the change reason needs to be immediately studied.

2. The method for determining GIS resonance based on vibration characteristic values according to claim 1, characterized in that, The preprocessing includes filtering, denoising and normalization processing.

3. The method of claim 2, wherein the method is characterized by, The reference characteristic parameter comprises a reference total vibration entropy H (ref) and a reference main frequency energy ratio p main(ref) characteristic parameters of the GIS device in a historical health state or characteristic parameters of a GIS device of the same structure in a health state; when the GIS device has characteristic parameters in a historical health state, the characteristic parameters in the historical health state are preferentially selected as the reference characteristic parameters; when the GIS device does not have characteristic parameters in a historical health state, the characteristic parameters of the GIS device of the same structure in a health state are selected as the reference characteristic parameters.

4. The method of claim 3, wherein the GIS resonance determination method based on the vibration characteristic value is characterized by, Step S4 is based on the GIS vibration spectrum signal y 1m (f) extracting the vibration characteristic parameters comprises: The main frequency f main-m The calculation process is: The GIS vibration frequency spectrum signal y is utilized 1m (f) Extracting the effective value A representing the I frequencies of 50i Hz (i = 1, 2, …, I) i , and selecting the frequency with the maximum effective value as the main frequency f main-m ; The calculation process of total vibration entropy H is: Wherein, P is total power; H value interval is [0, 1]; The main frequency energy ratio p main The calculation process is as follows: max(A i ) represents the maximum value of the effective value, i.e. the effective value of the main frequency f main-m .

5. The method of claim 3, wherein the GIS resonance determination method based on the vibration characteristic value is characterized by, In step S4, the expression of state characteristic parameter is: wherein H m represents the vibration entropy of the signal collected at the measuring point m, represents the dominant frequency energy ratio of the signal collected at the measuring point; M represents the total number of measuring points.

6. The GIS resonance judgment method based on vibration characteristic value according to claim 1, characterized in that: Dominant frequency f of m points main-m Generally consistent; When the main frequency f main-m If the main frequencies are not all the same, the value with the highest repetition rate of main frequency values is selected as the representative value to execute step S5. When the main frequency f main-m If all are different, it is considered that the GIS device has a fault at present and needs to stop running for inspection.

7. The method of claim 1, wherein the method is characterized by, The measuring points are located on the surface of the busbar cylinder of the GIS equipment, and there are five measuring points in total, wherein, the first and fifth measuring points are located at the left end and right end of the busbar cylinder respectively, the third measuring point is located at the middle part of the busbar cylinder, the second measuring point is located at the midpoint of the line connecting the first and third measuring points, and the fourth measuring point is located at the midpoint of the line connecting the third and fifth measuring points. 8.A GIS resonance judgment system based on vibration characteristic values, characterized in that, Comprise a group of vibration sensors and a host computer;The vibration sensors are arranged at the vibration measuring points on the surface of the GIS equipment shell for collecting signals and sending to the host computer;The host computer is used for receiving the signals transmitted by each vibration sensor and executing the method of any one of claims 1-7.

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