The invention content is as follows:
the invention aims to provide a method for extracting vibration signal characteristic parameters of a high-voltage alternating-current circuit breaker, which can be used for quickly and accurately extracting the vibration signal characteristic parameters and carrying out mode identification and state evaluation on mechanical faults.
The technical scheme adopted by the invention is as follows:
a vibration signal characteristic parameter extraction method for a high-voltage alternating-current circuit breaker comprises the following steps:
s100, vibration signal data (t) acquired on the time axisi,Ai) Constructing a discrete function, namely:
Ai=f(ti) i=1,2,…,N (1)
in the formula, t is time, A is vibration signal amplitude, and N is the number of sampling points;
applying the median filter function g to medfilt (y, n) versus the discrete function Ai=f(ti) Performing noise elimination processing twice, wherein y is discrete data to be filtered, and n is the size of a neighborhood window;
s200, extracting characteristic parameters by applying cubic spline fitting envelope curve to vibration signal data and prony algorithm to be combined to obtain m characteristic parameter arrays [ I ] of the vibration signal datamk,fk,ak,tNk],k=1,2,…,n;
S300, assuming that the calculation is terminated after m operations, obtaining m characteristic parameter arrays, namely: [ I ] ofmk,fk,ak,tNk]K is 1,2, …, m; the characteristic parameter fk、akThe mode of vibration is identified as a mode parameter, assuming a typical vibrationThe standard characteristic parameters of the failure modes are Iref、fref、arefDefining the weighted Euclidean distance lambda as:
when lambda is less than or equal to epsilon, the typical vibration fault exists; k is a radical of1、k2Is a weight coefficient, and epsilon is an evaluation deviation;
characteristic parameter I
mkAnd I
refRatio of
Obtaining two kinds of prompt information of failure and warning as the evaluation index of the vibration signal intensity; characteristic parameter t
NkIndicating the time when the vibration fault occurs this time.
The invention further improves the following steps: in step S100, the vibration signal acquisition device is composed of an acceleration sensor, an acquisition card, and an upper computer software system.
The invention further improves the following steps: step S200 specifically includes the following steps:
s201, in the first operation, the discrete function A after noise elimination is carried outi=f(ti) Intercepting a first section of single-frequency vibration data on a time window, namely:
A1i=f(ti) i=N1,2,…,N1end (2)
in the formula, N1To intercept the start position of the sampled data, N1endThe end position of the sample data is intercepted;
applying prony algorithm to single-frequency vibration data A1i=f(ti) And (3) performing operation, and calculating to obtain the single-frequency data characteristic parameters: initial vibration amplitude Im1Frequency f1Attenuation coefficient a1;
And then obtaining a discrete expression of the single-frequency vibration signal as follows:
s202, in the second operation, the discrete data A is collectedi=f(ti) The first single-frequency vibration signal A 'determined by the first operation is stripped'1i;
And then, intercepting a second section of single-frequency vibration data on a time window, namely:
A2i=f(ti) i=N2,2,…,N2end (4)
in the formula, N2To intercept the start position of the sampled data, N2endIntercepting the end position of the sampled data;
applying prony algorithm to single-frequency vibration data A2i=f(ti) And (3) performing operation, and calculating to obtain the single-frequency data characteristic parameters: initial vibration amplitude Im2Frequency f2Attenuation coefficient a2
And further obtaining an analytic expression of the single-frequency vibration signal as follows:
s203, during the k-th operation, the discrete data A is collected
i=f(t
i) K-1 single-frequency vibration signals determined k-1 times before stripping
And then intercepting the kth section of single-frequency vibration data on a time window, namely:
Aki=f(ti) i=Nk,2,…,Nkend (6)
in the formula, NkTo intercept the start position of the sampled data, NkendIntercepting the end position of the sampled data;
applying prony algorithm to single-frequency vibration data Aki=f(ti) Performing operation and calculationObtaining the single-frequency data characteristic parameters: initial vibration amplitude ImkFrequency fkAttenuation coefficient ak(ii) a The analytical expression of the single-frequency vibration signal is obtained as follows:
setting a threshold value gamma, and setting the initial vibration amplitude I of the k-th operationmk<F, the operation is terminated; otherwise, the calculation process of step S203 is repeated.
The invention further improves the following steps: in S201, N
1Is a vibration signal (t)
i,A
i) Using cubic spline fitting algorithm to obtain vibration signal A
i=f(t
i) Upper and lower envelope s of the peak
1、s
2Line of mean value
When large fluctuation occurs on the time axis, the sampling point N corresponding to the moment is taken
1endTo intercept the end position of the sampled data.
The invention further improves the following steps: in S203, k1、k2The values are respectively 0.9 and 0.1, the value range of epsilon is 0-0.3, or the value is set according to field experience values.
The invention further improves the following steps: in S300, when R is more than or equal to 0.8str<1, sending out a fault signal.
The invention further improves the following steps: when R is more than or equal to 0.2str<A warning signal is sent out when the temperature is 0.5 ℃; when R is more than or equal to 0.5str<At 0.8, a fault or warning signal may be issued based on field experience.
Compared with the prior art, the invention at least has the following technical effects:
the invention relates to a method for extracting the characteristic parameters of a vibration signal of a high-voltage alternating-current circuit breaker, which combines the application of cubic spline fitting envelope curve to the vibration signal data and the extraction of the characteristic parameters by a prony algorithm to obtain m characteristic parameter arrays [ I ] of the vibration signal datamk,fk,ak,tNk]And k is 1,2, …, n. Will f isk、akAs modal parameters, identifying the vibration failure modemkFor evaluating the intensity of vibration of the mode, tNkWhich is used to indicate the moment when the mode vibration fault occurs. The invention can quickly and accurately extract the vibration signal characteristic parameters and carry out mode identification and state evaluation on mechanical faults.
Detailed Description
In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.
A vibration signal characteristic parameter extraction method for a high-voltage alternating-current circuit breaker comprises the following steps:
1) from vibration signal data (t) acquired on the time axisi,Ai) Constructing a discrete function, namely:
Ai=f(ti) i=1,2,…,N (1)
in the formula, t is time, A is vibration signal amplitude, and N is the number of sampling points.
Applying the median filter function g to medfilt (y, n) versus the discrete function Ai=f(ti) And (5) denoising twice, wherein y is discrete data to be filtered, and n is the size of a neighborhood window.
The device for acquiring the vibration signals comprises an acceleration sensor, an acquisition card and an upper computer software system, wherein the acceleration sensor is front-end measurement equipment of the vibration signals, and the vibration signals measured by the acceleration sensor are input into the data acquisition card and transmitted to the upper computer through the acquisition card to acquire and process data.
2) For the first operation, the discrete function A after noise elimination is performedi=f(ti) Intercepting a first section of single-frequency vibration data on a time window, namely:
A1i=f(ti) i=N1,2,…,N1end (2)
in the formula, N1To intercept the start position of the sampled data, N1endThe end position of the sampled data is truncated.
Applying prony algorithm to single-frequency vibration data A1i=f(ti) And (3) performing operation, and calculating to obtain the single-frequency data characteristic parameters: initial vibration amplitude Im1Frequency f1Attenuation coefficient a1. Further, the discrete expression of the single-frequency vibration signal can be obtained as follows:
preferably, in step 2), N
1Is a vibration signal (t)
i,A
i) Using cubic spline fitting algorithm to obtain vibration signal A
i=f(t
i) Upper and lower envelope s of the peak
1、s
2Line of mean value
When large fluctuation occurs on the time axis, the sampling point N corresponding to the moment is taken
1endTo intercept the end position of the sampled data.
3) From the discrete data A collected during the second operationi=f(ti) The first single-frequency vibration signal A 'determined by the first operation is stripped'1i. Further, intercepting a second segment of single-frequency vibration data on the time window, namely:
A2i=f(ti) i=N2,2,…,N2end (4)
in the formula, N2To intercept the start position of the sampled data, N2endTo intercept the end position of the sampled data.
Applying prony algorithm to single-frequency vibration data A2i=f(ti) And (3) performing operation, and calculating to obtain the single-frequency data characteristic parameters: initial vibration amplitude Im2Frequency f2Attenuation coefficient a2. Further, the analytic expression of the single-frequency vibration signal can be obtained as follows:
4) at the k-th operation, discrete data A is collected
i=f(t
i) K-1 single-frequency vibration signals determined k-1 times before stripping
Further, intercepting the kth section of single-frequency vibration data on a time window, namely:
Aki=f(ti) i=Nk,2,…,Nkend (6)
in the formula, NkTo intercept the start position of the sampled data, NkendTo intercept the end position of the sampled data.
Applying prony algorithm to single-frequency vibration data Aki=f(ti) And (3) performing operation, and calculating to obtain the single-frequency data characteristic parameters: initial vibration amplitude ImkFrequency fkAttenuation coefficient ak. Further, the analytic expression of the single-frequency vibration signal can be obtained as follows:
setting a threshold value gamma, and setting the initial vibration amplitude I of the k-th operationmk<Γ, the operation terminates. Otherwise, repeating the calculation process of the step.
5) Assuming that the calculation is terminated after m operations, m characteristic parameter arrays can be obtained, namely: [ I ] ofmk,fk,ak,tNk]And k is 1,2, …, m. The characteristic parameter fk、akPerforming vibration fault mode identification as modal parameters, and respectively assuming that standard characteristic parameters of typical vibration fault modes are Iref、fref、arefDefining the weighted Euclidean distance lambda as:
when λ ≦ ε, this typical vibration failure is indicated. k is a radical of1、k2Is a weight coefficient, and ε is an evaluation deviation.
Characteristic parameter I
mkAnd I
refRatio of
And obtaining two kinds of prompt information of failure and warning as the evaluation index of the vibration signal intensity. Characteristic parameter t
NkIndicating the time when the vibration fault occurs this time.
As a preferred embodiment, k1、k2The values are respectively 0.9 and 0.1, the value range of epsilon is 0-0.3, or the value is set according to field experience values.
When R is more than or equal to 0.8str<When 1, sending out a fault signal; when R is more than or equal to 0.2str<A warning signal is sent out when the temperature is 0.5 ℃; when R is more than or equal to 0.5str<At 0.8, a fault or warning signal may be issued based on field experience.
The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
Examples
With reference to fig. 1 to 3, a method for extracting a vibration signal characteristic parameter of a high-voltage alternating-current circuit breaker includes the following steps:
1) according to the vibration signal (t) shown in FIG. 1i,Ai) Constructing a discrete function, namely:
Ai=f(ti) i=1,2,…,N (1)
in the formula, t is time, A is vibration signal amplitude, and N is the number of sampling points.
2) For the first operation, for the discrete function Ai=f(ti) Intercepting a first section of single-frequency vibration data on a time window, namely:
A1i=f(ti) i=N1,2,…,N1end (2)
in the formula, N
1To intercept the start position of the sampled data, N
1endTo intercept the end position of the sampled data. The vibration signal A is derived by applying spline fitting as shown in FIG. 2
i=f(t
i) Upper and lower envelope s of the peak
1、s
2Line of mean value
And when large fluctuation occurs on the time axis, taking the sampling point corresponding to the moment as an end position.
Applying prony algorithm to single-frequency vibration data A1i=f(ti) And (3) performing operation, and calculating to obtain the single-frequency data characteristic parameters: initial vibration amplitude Im1Frequency f1Attenuation coefficient a1. Further, the discrete expression of the single-frequency vibration signal can be obtained as follows:
3) from the discrete data A collected during the second operationi=f(ti) The first single-frequency vibration signal A 'determined by the first operation is stripped'1i. Further, intercepting a second segment of single-frequency vibration data on the time window, namely:
A2i=f(ti) i=N2,2,…,N2end (4)
in the formula, N2To intercept the start position of the sampled data, N2endTo intercept the end position of the sampled data.
Applying prony algorithm to single-frequency vibration data A2i=f(ti) And (3) performing operation, and calculating to obtain the single-frequency data characteristic parameters: initial vibration amplitude Im2Frequency f2Attenuation coefficient a2. Further, the analytic expression of the single-frequency vibration signal can be obtained as follows:
4) after 5 times of calculation, 5 vibration modes are obtained after the calculation is terminated, and the characteristic parameters of each mode are shown in the following table:
vibration mode
|
Amplitude (m/s)2)
|
Frequency (Hz)
|
Coefficient of attenuation
|
Moment of oscillation(s)
|
1
|
0.15
|
1000
|
64.9
|
0.15
|
2
|
0.30
|
4000
|
79.9
|
0.02
|
3
|
1.00
|
6000
|
70.0
|
0.025
|
4
|
0.50
|
8000
|
54.9
|
0.04
|
5
|
0.20
|
2600
|
49.6
|
0.05 |
6) The characteristic parameter fk、akPerforming vibration fault mode identification as modal parameters, and respectively assuming that standard characteristic parameters of typical vibration fault modes are Iref、fref、arefDefining the weighted Euclidean distance lambda as:
when λ ≦ 0.1, this typical vibration failure is indicated. k is a radical of1、k2The values are respectively 0.9 and 0.1, and epsilon is the evaluation deviation.
7) Characteristic parameter I
mkAnd I
refRatio of
And obtaining two kinds of prompt information of failure and warning as the evaluation index of the vibration signal intensity. When R is more than or equal to 0.8
str<When 1, sending out a fault signal; when R is more than or equal to 0.2
str<A warning signal is emitted at 0.8.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are hereby incorporated by reference for all purposes. The omission in the foregoing claims of any aspect of subject matter that is disclosed herein is not intended to forego such subject matter, nor should the applicant consider that such subject matter is not considered part of the disclosed subject matter.