CN111665405A - Vibration and sound detection signal filtering method and system based on sparsity minimization - Google Patents
Vibration and sound detection signal filtering method and system based on sparsity minimization Download PDFInfo
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Abstract
The embodiment of the invention discloses a vibration and sound detection signal filtering method and system utilizing sparsity minimization, wherein the method comprises the following steps: step 101, acquiring a signal sequence S acquired according to a time sequence; step 102, obtaining a sparsity factor P; step 103, obtaining a sparse matrix A; step 104, obtaining the signal sequence S after noise filteringnew。
Description
Technical Field
The invention relates to the field of electric power, in particular to a method and a system for filtering a vibration and sound detection signal of a transformer.
Background
With the high-speed development of the smart grid, the safe and stable operation of the power equipment is particularly important. At present, the detection of the operating state of the power equipment with ultrahigh voltage and above voltage grades, especially the detection of the abnormal state, is increasingly important and urgent. As an important component of an electric power system, a power transformer is one of the most important electrical devices in a substation, and its reliable operation is related to the safety of a power grid. Generally, the abnormal state of the transformer can be divided into core abnormality and winding abnormality. The core abnormality is mainly represented by core saturation, and the winding abnormality generally includes winding deformation, winding looseness and the like.
The basic principle of the transformer abnormal state detection is to extract each characteristic quantity in the operation of the transformer, analyze, identify and track the characteristic quantity so as to monitor the abnormal operation state of the transformer. The detection method can be divided into invasive detection and non-invasive detection according to the contact degree; the detection can be divided into live detection and power failure detection according to whether the shutdown detection is needed or not; the method can be classified into an electrical quantity method, a non-electrical quantity method, and the like according to the type of the detected quantity. In comparison, the non-invasive detection has strong transportability and is more convenient to install; the live detection does not affect the operation of the transformer; the non-electric quantity method is not electrically connected with the power system, so that the method is safer. The current common detection methods for the operation state of the transformer include a pulse current method and an ultrasonic detection method for detecting partial discharge, a frequency response method for detecting winding deformation, a vibration detection method for detecting mechanical and electrical faults, and the like. The detection methods mainly detect the insulation condition and the mechanical structure condition of the transformer, wherein the detection of the vibration signal (vibration sound) of the transformer is the most comprehensive, and the fault and the abnormal state of most transformers can be reflected.
In the running process of the transformer, the magnetostriction of the iron core silicon steel sheets and the vibration caused by the winding electrodynamic force can radiate vibration sound signals with different amplitudes and frequencies to the periphery. When the transformer normally operates, uniform low-frequency noise is emitted outwards; if the sound is not uniform, it is not normal. The transformer can make distinctive sounds in different running states, and the running state of the transformer can be mastered by detecting the sounds made by the transformer. It is worth noting that the detection of the sound emitted by the transformer in different operating states not only can detect a plurality of serious faults causing the change of the electrical quantity, but also can detect a plurality of abnormal states which do not endanger the insulation and do not cause the change of the electrical quantity, such as the loosening of internal and external parts of the transformer, and the like.
Because the vibration sound detection method utilizes the vibration signal sent by the transformer, the vibration sound detection method is easily influenced by environmental noise, and therefore, how to effectively identify the vibration sound and the noise is the key for success of the method.
Disclosure of Invention
Because the vibration sound detection method utilizes the vibration signal sent by the transformer, the vibration sound detection method is easily influenced by environmental noise, and therefore, how to effectively identify the vibration sound and the noise is the key for success of the method.
The invention aims to provide a vibration and sound detection signal filtering method and system based on sparsity minimization, wherein the method utilizes the characteristics that a transformer vibration and sound signal, impulse noise and background noise come from different information sources, and realizes the separation and filtering of the background noise (including abnormal points) and the impulse noise according to sparsity minimization. The method has better robustness and simpler calculation.
In order to achieve the purpose, the invention provides the following scheme:
a vibro-acoustic detection signal filtering method with sparsity minimization, comprising:
step 101, acquiring a signal sequence S acquired according to a time sequence;
step 102, obtaining a sparsity factor P, specifically: arranging N eigenvalues of the normalized correlation matrix B according to ascending order to obtain an eigenvalue setFor the feature value setEach of the feature values in (a) determines whether or not σ is greater than or equal tobAll greater than or equal to σbAdding said characteristic value of (2) to a threshold setIn (2), the threshold value set is obtainedThe sequence number of the minimum element in the feature value set C is assigned to the sparsity factor P. Wherein, the calculation formula of the normalized correlation matrix B isN is the length of the signal sequence S; sigmabIs the mean square error of the sparse vector b; the calculation formula of the sparse vector b is that b is equal to U; u is a left characteristic vector matrix of the normalized correlation matrix B; a characteristic value matrix of the normalized correlation matrix B; m is0Is the mean of the signal sequence S;
step 103, obtaining a sparse matrix a, specifically: the calculation formula of the sparse matrix A is that A is equal to U*And V. Wherein V is a right eigenvector matrix of the normalized correlation matrix B;*is a matrix of eigenvalues of the sparse matrix A, the sparsificationEigenvalue matrix of matrix A*The calculation method comprises the following steps: the sum of the values of the diagonal elements of the eigenvalue matrix of the normalized correlation matrix Bσ0Is the mean square error of the signal sequence S;
step 104, obtaining the signal sequence S after noise filteringnewThe method specifically comprises the following steps: among all the intermediate parameter vectors x, are selected such thatTaking the intermediate parameter vector x with the minimum value as the signal sequence S after noise filteringnew. Wherein λ ismaxIs the largest eigenvalue of the normalized correlation matrix B.
A vibro-acoustic detection signal filtering system with sparsity minimization, comprising:
the module 201 acquires a signal sequence S acquired in time sequence;
the module 202 finds the sparsity factor P, specifically: arranging N eigenvalues of the normalized correlation matrix B according to ascending order to obtain an eigenvalue setFor the feature value setEach of the feature values in (a) determines whether or not σ is greater than or equal tobAll greater than or equal to σbAdding said characteristic value of (2) to a threshold setIn (2), the threshold value set is obtainedIs determined, the minimum element is included in the set of feature valuesThe sequence number in (2) is assigned to the sparsity factor P. Wherein, the calculation formula of the normalized correlation matrix B isN is the length of the signal sequence S; sigmabIs the mean square error of the sparse vector b; the calculation formula of the sparse vector b is that b is equal to U; u is a left characteristic vector matrix of the normalized correlation matrix B; a characteristic value matrix of the normalized correlation matrix B; m is0Is the mean of the signal sequence S;
the module 203 finds a sparse matrix a, specifically: the calculation formula of the sparse matrix A is that A is equal to U*And V. Wherein V is a right eigenvector matrix of the normalized correlation matrix B;*is the eigenvalue matrix of the sparse matrix A, the eigenvalue matrix of the sparse matrix A*The calculation method comprises the following steps: the sum of the values of the diagonal elements of the eigenvalue matrix of the normalized correlation matrix Bσ0Is the mean square error of the signal sequence S;
module 204 finds the noise-filtered signal sequence SnewThe method specifically comprises the following steps: among all the intermediate parameter vectors x, are selected such thatTaking the intermediate parameter vector x with the minimum value as the signal sequence S after noise filteringnew. Wherein λ ismaxIs the largest eigenvalue of the normalized correlation matrix B.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
because the vibration sound detection method utilizes the vibration signal sent by the transformer, the vibration sound detection method is easily influenced by environmental noise, and therefore, how to effectively identify the vibration sound and the noise is the key for success of the method.
The invention aims to provide a vibration and sound detection signal filtering method and system based on sparsity minimization, wherein the method utilizes the characteristics that a transformer vibration and sound signal, impulse noise and background noise come from different information sources, and realizes the separation and filtering of the background noise (including abnormal points) and the impulse noise according to sparsity minimization. The method has better robustness and simpler calculation.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
FIG. 1 is a schematic flow diagram of the process of the present invention;
FIG. 2 is a schematic flow chart of the system of the present invention;
FIG. 3 is a flow chart illustrating an embodiment of the present invention.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
FIG. 1 is a schematic flow chart of a vibro-acoustic detection signal filtering method using sparsity minimization
Fig. 1 is a schematic flow chart of a vibro-acoustic detection signal filtering method using sparsity minimization according to the present invention. As shown in fig. 1, the method for filtering a vibro-acoustic detection signal by minimizing sparsity specifically includes the following steps:
step 101, acquiring a signal sequence S acquired according to a time sequence;
step 102, obtaining a sparsity factor P, specifically: arranging N eigenvalues of the normalized correlation matrix B according to ascending order to obtain an eigenvalue setFor the feature value setEach of the feature values in (a) determines whether or not σ is greater than or equal tobAll greater than or equal to σbAdding said characteristic value of (2) to a threshold setIn (2), the threshold value set is obtainedIs determined, the minimum element is included in the set of feature valuesThe sequence number in (2) is assigned to the sparsity factor P. Wherein, the calculation formula of the normalized correlation matrix B isN is the length of the signal sequence S; sigmabIs the mean square error of the sparse vector b; the calculation formula of the sparse vector b is that b is equal to U; u is a left characteristic vector matrix of the normalized correlation matrix B; a characteristic value matrix of the normalized correlation matrix B; m is0Is the mean of the signal sequence S;
step 103, obtaining a sparse matrix a, specifically: the calculation formula of the sparse matrix A is that A is equal to U*And V. Wherein V is a right eigenvector matrix of the normalized correlation matrix B;*is the eigenvalue matrix of the sparse matrix A, the eigenvalue matrix of the sparse matrix A*The calculation method comprises the following steps: what is needed isAdding the values of diagonal elements of the eigenvalue matrix of the normalized correlation matrix Bσ0Is the mean square error of the signal sequence S;
step 104, obtaining the signal sequence S after noise filteringnewThe method specifically comprises the following steps: among all the intermediate parameter vectors x, are selected such thatTaking the intermediate parameter vector x with the minimum value as the signal sequence S after noise filteringnew. Wherein λ ismaxIs the largest eigenvalue of the normalized correlation matrix B.
FIG. 2 structural intent of a vibro-acoustic detection signal filtering system with sparsity minimization
Fig. 2 is a schematic structural diagram of a vibro-acoustic detection signal filtering system using sparsity minimization according to the present invention. As shown in fig. 2, the vibro-acoustic detection signal filtering system using sparsity minimization includes the following structure:
the module 201 acquires a signal sequence S acquired in time sequence;
the module 202 finds the sparsity factor P, specifically: arranging N eigenvalues of the normalized correlation matrix B according to ascending order to obtain an eigenvalue setFor the feature value setEach of the feature values in (a) determines whether or not σ is greater than or equal tobAll greater than or equal to σbAdding said characteristic value of (2) to a threshold setIn (2), the threshold value set is obtainedIs determined, the minimum element is included in the set of feature valuesThe sequence number in (2) is assigned to the sparsity factor P. Wherein, the calculation formula of the normalized correlation matrix B isN is the length of the signal sequence S; sigmabIs the mean square error of the sparse vector b; the calculation formula of the sparse vector b is that b is equal to U; u is a left characteristic vector matrix of the normalized correlation matrix B; a characteristic value matrix of the normalized correlation matrix B; m is0Is the mean of the signal sequence S;
the module 203 finds a sparse matrix a, specifically: the calculation formula of the sparse matrix A is that A is equal to U*And V. Wherein V is a right eigenvector matrix of the normalized correlation matrix B;*is the eigenvalue matrix of the sparse matrix A, the eigenvalue matrix of the sparse matrix A*The calculation method comprises the following steps: the sum of the values of the diagonal elements of the eigenvalue matrix of the normalized correlation matrix Bσ0Is the mean square error of the signal sequence S;
module 204 finds the noise-filtered signal sequence SnewThe method specifically comprises the following steps: among all the intermediate parameter vectors x, are selected such thatTaking the intermediate parameter vector x with the minimum value as the signal sequence S after noise filteringnew. Wherein λ ismaxIs the largest eigenvalue of the normalized correlation matrix B.
The following provides an embodiment for further illustrating the invention
FIG. 3 is a flow chart illustrating an embodiment of the present invention. As shown in fig. 3, the method specifically includes the following steps:
step 301, acquiring a signal sequence S acquired according to a time sequence;
step 302, obtaining a sparsity factor P, specifically: arranging N eigenvalues of the normalized correlation matrix B according to ascending order to obtain an eigenvalue setFor the feature value setEach of the feature values in (a) determines whether or not σ is greater than or equal tobAll greater than or equal to σbAdding said characteristic value of (2) to a threshold setIn (2), the threshold value set is obtainedIs determined, the minimum element is included in the set of feature valuesThe sequence number in (2) is assigned to the sparsity factor P. Wherein, the calculation formula of the normalized correlation matrix B isN is the length of the signal sequence S; sigmabIs the mean square error of the sparse vector b; the calculation formula of the sparse vector b is that b is equal to U; u is a left characteristic vector matrix of the normalized correlation matrix B; a characteristic value matrix of the normalized correlation matrix B; m is0Is the mean of the signal sequence S;
step 303, obtaining a sparse matrix a, specifically: the calculation formula of the sparse matrix A is that A is equal to U*And V. Wherein V is a right eigenvector matrix of the normalized correlation matrix B;*is the eigenvalue matrix of the sparse matrix A, the eigenvalue matrix of the sparse matrix A*The calculation method comprises the following steps: the normalized correlationValue addition of diagonal elements of eigenvalue matrix of matrix Bσ0Is the mean square error of the signal sequence S;
step 304 is to obtain the signal sequence S after noise filteringnewThe method specifically comprises the following steps: among all the intermediate parameter vectors x, are selected such thatTaking the intermediate parameter vector x with the minimum value as the signal sequence S after noise filteringnew. Wherein λ ismaxIs the largest eigenvalue of the normalized correlation matrix B.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is simple because the system corresponds to the method disclosed by the embodiment, and the relevant part can be referred to the method part for description.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
Claims (2)
1. The method for filtering the vibration and sound detection signal by utilizing sparsity minimization is characterized by comprising the following steps of:
step 101, acquiring a signal sequence S acquired according to a time sequence;
step 102, obtaining a sparsity factor P, specifically: arranging N eigenvalues of the normalized correlation matrix B according to ascending order to obtain an eigenvalue setFor the feature value setEach of the feature values in (a) determines whether or not σ is greater than or equal tobAll greater than or equal to σbAdding said characteristic value of (2) to a threshold setIn (2), the threshold value set is obtainedIs determined, the minimum element is included in the set of feature valuesThe sequence number in (2) is assigned to the sparsity factor P. Wherein, the calculation formula of the normalized correlation matrix B isN is the length of the signal sequence S; sigmabIs the mean square error of the sparse vector b; the calculation formula of the sparse vector b is that b is equal to U; u is a left characteristic vector matrix of the normalized correlation matrix B; a characteristic value matrix of the normalized correlation matrix B; m is0Is the mean of the signal sequence S;
step 103, obtaining a sparse matrix a, specifically: the calculation formula of the sparse matrix A is that A is equal to U*And V. Wherein V is a right eigenvector matrix of the normalized correlation matrix B;*is the eigenvalue matrix of the sparse matrix A, the eigenvalue matrix of the sparse matrix A*The calculation method comprises the following steps: the sum of the values of the diagonal elements of the eigenvalue matrix of the normalized correlation matrix Bσ0Is the mean square error of the signal sequence S;
step 104, obtaining the signal sequence S after noise filteringnewThe method specifically comprises the following steps: among all the intermediate parameter vectors x, are selected such thatTaking the intermediate parameter vector x with the minimum value as the signal sequence S after noise filteringnew. Wherein λ ismaxIs the largest eigenvalue of the normalized correlation matrix B.
2. The vibration and sound detection signal filtering system using sparsity minimization is characterized by comprising:
the module 201 acquires a signal sequence S acquired in time sequence;
the module 202 finds the sparsity factor P, specifically: arranging N eigenvalues of the normalized correlation matrix B according to ascending order to obtain an eigenvalue setFor the feature value setEach of the feature values in (a) determines whether or not σ is greater than or equal tobAll greater than or equal to σbAdding said characteristic value of (2) to a threshold setIn (2), the threshold value set is obtainedIs determined, the minimum element is included in the set of feature valuesThe sequence number in (2) is assigned to the sparsity factor P. Wherein, the calculation formula of the normalized correlation matrix B isN is the length of the signal sequence S; sigmabIs the mean square error of the sparse vector b; the calculation formula of the sparse vector b is that b is equal to U; u is a left characteristic vector matrix of the normalized correlation matrix B; a characteristic value matrix of the normalized correlation matrix B; m is0Is the mean of the signal sequence S;
the module 203 finds a sparse matrix a, specifically: the calculation formula of the sparse matrix A is that A is equal to U*And V. Wherein V is a right eigenvector matrix of the normalized correlation matrix B;*is the eigenvalue matrix of the sparse matrix A, the eigenvalue matrix of the sparse matrix A*The calculation method comprises the following steps: the sum of the values of the diagonal elements of the eigenvalue matrix of the normalized correlation matrix Bσ0Is the mean square error of the signal sequence S;
module 204 finds the noise-filtered signal sequence SnewThe method specifically comprises the following steps: among all the intermediate parameter vectors x, are selected such thatTaking the intermediate parameter vector x with the minimum value as the signal sequence S after noise filteringnew. Wherein λ ismaxIs the largest eigenvalue of the normalized correlation matrix B.
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Cited By (2)
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CN112415439A (en) * | 2020-11-04 | 2021-02-26 | 华北电力大学 | Vibration and sound detection signal filtering method and system using sparse projection |
CN112434567A (en) * | 2020-11-06 | 2021-03-02 | 华北电力大学 | Power signal filtering method and system by using noise jitter property |
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CN112415439A (en) * | 2020-11-04 | 2021-02-26 | 华北电力大学 | Vibration and sound detection signal filtering method and system using sparse projection |
CN112415439B (en) * | 2020-11-04 | 2021-11-19 | 华北电力大学 | Vibration and sound detection signal filtering method and system using sparse projection |
CN112434567A (en) * | 2020-11-06 | 2021-03-02 | 华北电力大学 | Power signal filtering method and system by using noise jitter property |
CN112434567B (en) * | 2020-11-06 | 2021-11-19 | 华北电力大学 | Power signal filtering method and system by using noise jitter property |
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