Method for separating three-phase signals of reactive fling-cut switch based on PCA (Principal Component Analysis) algorithm and antenna array

Abstract

The invention relates to the technical field of power switches, in particular to a reactive switching switch three-phase signal separation method based on a PCA algorithm and an antenna array. The method comprises the following steps of: firstly, receiving radiation electromagnetic waves emitted when a field reactive switching switch is switched on and off through an antenna array, then amplifying and denoising the radiation electromagnetic waves through a signal collector, storing the radiation electromagnetic waves into a storage module, and then processing measured signals by using an improved PCA algorithm to realize signal separation of a three-phase arc extinguish chamber of the reactive switching switch, so as to realize the three-phase arc extinguish chamber of the reactive switching switch. And obtaining each phase arc extinguish chamber signal of the reactive switching switch. Independent arc extinguish chamber signals of the A phase, the B phase and the C phase can be extracted from mixed signals actually measured on site, accurate diagnosis of the states of the phases of the arc extinguish chamber of the reactive switching switch is achieved, field workers do not need to disassemble and overhaul the three phases of the reactive switching switch, only one or more phases need to be maintained, and the detection and maintenance efficiency can be greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power switches, namely, a three-phase signal separation method of a reactive switching switch based on a PCA algorithm and an antenna array. Background Art

[0002] In existing technology, reactive power switching switches are numerous in power grids, serving a control and protection role. As key components in reactive power compensation systems, reactive power switching switches operate frequently, making contact welding a risk during closing and potentially causing severe breakdowns or even explosions during opening, seriously impacting power grid safety. The state of the arcing contacts in reactive power switching switches directly affects their arc extinguishing capability. During the opening and closing process, the radiated electromagnetic wave signals emitted by the contacts within the arc extinguishing chamber reflect the state of the arc extinguishing chamber. When the reactive power switching switch contacts deteriorate, the radiated electromagnetic wave signals become distorted, which can be used to diagnose and evaluate the status of the reactive power switching switch. However, during the reactive switching process, the arc extinguishing chambers corresponding to the three phases will all emit electromagnetic wave signals. For a single sensor, the signal it measures is a three-phase mixed signal. The three-phase mixed signal can only determine the overall state of the reactive switching switch, and the actual state of each phase cannot be determined. In particular, once there is a problem in a phase, it is impossible to determine which specific one it is, which brings certain difficulties to subsequent maintenance. Therefore, realizing the separation of the three-phase signals of the reactive switching switch has become an urgent problem that needs to be solved. Summary of the Invention

[0003] The purpose of the present invention is to address the above shortcomings and provide a method for separating three-phase signals of reactive switching switches based on PCA algorithm and antenna array to achieve rapid extraction of signals from each phase interrupter, thereby solving the problem that the existing three-phase interrupter signals of reactive switching switches are mixed and difficult to separate.

[0004] The technical solution of the present invention is: a three-phase signal separation method for a reactive switching switch based on a PCA algorithm and an antenna array, the steps of which are as follows: first, the radiated electromagnetic waves emitted when the on-site reactive switching switch is disconnected are received by the antenna array, then amplified and denoised by a signal collector and stored in a storage module, and then the measured signals are processed using an improved PCA algorithm to achieve three-phase arc extinguishing chamber signal separation of the reactive switching switch and obtain the arc extinguishing chamber signals of each phase of the reactive switching switch.

[0005] The antenna is used to detect the radiated electromagnetic wave signal emitted during the reactive switching operation, convert it into a voltage signal and transmit it to the signal conditioner.

[0006] The signal collector is used to realize analog-to-digital conversion of the radiated electromagnetic wave signal emitted during the operation of the reactive switching switch, and storage and display of the digital signal.

[0007] The antenna is a narrowband antenna. For a three-phase reactive switching switch, at least four antennas are required. The entire array is arranged below phase A of the reactive switching switch. Three antennas face phases A, B, and C respectively, and the fourth antenna faces away from each phase of the reactive switching switch.

[0008] The advantages of the present invention are: the radiated electromagnetic waves emitted during the switching process of the reactive switching switch are measured by an antenna array, and the antenna array is used to realize that the mixed signals measured by each antenna have differences in amplitude, peak occurrence time, etc., and then the improved PCA algorithm is used to perform demixing processing on multiple groups of mixed signals. The separate arc extinguishing chamber signals of phases A, B, and C can be extracted from the mixed signals measured on site, thereby realizing accurate diagnosis of the status of each phase of the arc extinguishing chamber of the reactive switching switch. On-site staff do not need to disassemble and repair all three phases of the reactive switching switch, but only need to maintain one or several phases, which can greatly improve the efficiency of detection and maintenance.

[0009] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a diagram of a module for measuring electromagnetic waves radiated during the disconnection process of a reactive switching switch according to the present invention.

[0011] Figure 2 FIG. 1 is a schematic diagram of an on-site antenna array arrangement according to an embodiment of the present invention.

[0012] Figure 3 It is a schematic diagram of the improved PCA algorithm of the present invention. DETAILED DESCRIPTION

[0013] See also Figure 1 A three-phase signal separation method for reactive switching switches based on the PCA algorithm and antenna array operates as follows: During on-site reactive switching switch measurements, the antenna array collects the signals from the three-phase arc extinguishing chamber of the reactive switching switch. Due to the different arrangements of the antennas in the antenna array, the three-phase mixed signals measured by different antennas vary in amplitude, peak occurrence time, and other aspects. Therefore, the PCA algorithm can be used to perform three-phase separation on the measured mixed signal, obtaining the signals of each phase arc extinguishing chamber from the overall signal, thereby achieving three-phase separation of the effective electromagnetic wave signals radiated by the arc extinguishing chamber of the reactive switching switch. In addition, to address the low separation efficiency of the traditional PCA algorithm and the low correlation between the separation results and the source signal, an improved PCA algorithm is proposed. Multiple groups of different white noise are first added to the original signal, and then EMD decomposition is performed. The IMF component obtained from the EMD decomposition with the highest correlation with the mixed signal is taken as the processed demixing signal. This method can effectively suppress modal aliasing and make the decomposed components smoother in the presence of transient interference.

[0014] The advantage of the present invention is that the mixed signals of the reactive switching switch obtained by the antenna array have amplitude and time differences, and the improved PCA algorithm is used to separate the mixed signals. The antenna and the reactive switching switch are non-contact and the improved PCA algorithm does not require a high data sampling rate. Therefore, the extraction of the arc extinguishing chamber signals of each phase of the reactive switching switch is more efficient and concise, and the status of each phase of the reactive switching switch can be determined separately, thereby improving the efficiency of detection and maintenance.

[0015] See also Figure 1 , is a module diagram for measuring electromagnetic waves radiated during the disconnection process of a reactive switching switch, including: an antenna, a signal acquisition unit and a processor.

[0016] Antennas detect the radiated electromagnetic wave signals emitted during the operation of the reactive power switching device, convert them into voltage signals, and transmit them to the signal conditioner. To avoid interference from the substation, narrowband antennas are preferred. For a three-phase reactive power switching device, at least four antennas are required. The entire array should be placed below phase A of the reactive power switching device, with three antennas facing phases A, B, and C respectively, and the fourth antenna facing away from each phase of the reactive power switching device.

[0017] The high-speed signal collector is used to realize the analog-to-digital conversion of the radiated electromagnetic wave signal emitted during the reactive switching operation, the storage and display of the digital signal, and the separation of the arc extinguishing chamber signal of each phase from the overall signal, and provide the separation results of each phase signal.

[0018] The post-processing module is used to separate the arc extinguishing chamber signals of each phase from the measured overall signal and provide the separation results of each phase signal.

[0019] See also Figure 2 , is a schematic diagram of the on-site antenna array arrangement according to an embodiment of the present invention. The antenna array as a whole is 2 m away from the reactive switching switch A.

[0020] In this method, an antenna array is first used to receive the radiated electromagnetic waves emitted when the on-site reactive switching switch is opened. For a three-phase reactive switching switch, at least four antennas are required. The entire array is arranged below phase A of the reactive switching switch, with three antennas facing phases A, B, and C respectively, and the fourth antenna facing away from each phase of the reactive switching switch. The measured signal is then amplified and denoised by a signal collector and stored in a storage module. The measured signal is then processed using an improved PCA algorithm to separate the three-phase arc extinguishing chamber signals of the reactive switching switch and obtain the arc extinguishing chamber signals of each phase of the reactive switching switch.

[0021] See also Figure 3This is a schematic diagram of the improved PCA algorithm of the present invention. Start → Stored radiated electromagnetic wave data → Add white noise → EMD decomposition → Normalize → Calculate eigenvalues and eigenvectors → Calculate cumulative contribution rates → Select the one with the highest cumulative contribution rate → End. Repeat the white noise addition and EMD decomposition multiple times.

[0022] The detailed principles of the improved PCA algorithm are as follows:

[0023] First, add white noise to the mixed signal and perform EMD decomposition. Add Gaussian white noise ω(t) that obeys the normal distribution to the source signal x(t) to obtain:

[0024] X(t)=x(t)+ω(t).

[0025] Then perform empirical mode decomposition on the obtained signal X(t) to obtain:

[0026]

[0027] where c n (t) is the nth IMF component, K is the number of IMFs after decomposition, r K (t) is the decomposed rainfall. Then add white noise with different normal distributions and repeat the above operation N times to obtain:

[0028]

[0029] The resulting IMF components are:

[0030] Solve the correlation between the above IMF components and the source signal:

[0031]

[0032] Where X is the mixed signal of a single channel, c j is the jth IMF component of the corresponding mixed signal, D(X) is the variance of signal X, D(c j ) is signal c j The variance of COV(X,c j ) are signal X and signal c j The covariance of is calculated, and the IMF component with the highest correlation is taken as the corresponding channel mixed signal after dimensionality reduction. The above dimensionality reduction operation is performed on each channel mixed signal obtained by measurement, and the IMF component after dimensionality reduction is used as the initial matrix X calculated by the PCA algorithm.

[0033] The calculation principle of the PCA algorithm is as follows: for n samples and p indicators, a sample matrix x of size n×p can be constructed:

[0034]

[0035] To find a new set of variables z 1,z2,…,z m (m≤p), and satisfy:

[0036]

[0037] For the coefficient l ij The determination of the following five principles must be met:

[0038] 1)z i With z j (i≠j; i, j=1, 2,…, m) are independent of each other.

[0039] 2) z1 is x1, x2, ..., x p The linear combination with the largest variance.

[0040] 3) z2 is x1, x2, ..., x2 which are not related to z1 p The linear combination with the largest variance.

[0041] 4) By analogy, z m is related to z1,z2,…,z m-1 Uncorrelated x1,x2,...,x p The linear combination with the largest variance.

[0042] 5) New variable indicators z1, z2, …, z m become the original variable indicators x1, x2, ..., x p The first, second, ... mth principal component of .

[0043] The calculation process is as follows:

[0044] 1) Standardization:

[0045] Compute column-wise means:

[0046] Standard Deviation:

[0047] Normalize data:

[0048] The original sample matrix after normalization is:

[0049]

[0050] 2) Calculate the covariance matrix of the standardized sample:

[0051]

[0052] You can get:

[0053]

[0054] 3) Calculate the eigenvalue and eigenvalue vector of R:

[0055] Eigenvalue λ1≥λ2≥…≥λ p ≥0(R is a semidefinite matrix, and

[0056] The eigenvectors are:

[0057]

[0058] 4) Calculate the principal component sharing rate and cumulative contribution rate:

[0059]

[0060] 5) Take the first, second, ... mth (m≤p) principal components corresponding to the eigenvalues with higher cumulative contribution rates, where the i-th principal component is:

[0061] F i =a 1i X1+a 2i X2+…+a pi X p .

[0062] For the separation of the three-phase signals of the reactive switching switch, X should be the signal matrix measured by the four antennas. The improved PCA algorithm is used to demix X, and the three principal components with the highest contribution rate are regarded as the arc extinguishing chamber signals of the three phases of the reactive switching switch.

[0063] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the radiated electromagnetic waves emitted during the switching process of the reactive switching switch are measured by an antenna array, and the antenna array is used to realize that the mixed signals measured by each antenna have differences in amplitude, peak occurrence time, etc., and then the improved PCA algorithm is used to perform demixing processing on multiple groups of mixed signals. The separate arc extinguishing chamber signals of phases A, B, and C can be extracted from the mixed signals measured on site, thereby realizing accurate diagnosis of the status of each phase of the arc extinguishing chamber of the reactive switching switch. On-site staff do not need to disassemble and repair all three phases of the reactive switching switch, but only need to maintain one or several phases, which can greatly improve the efficiency of detection and maintenance.

[0064] The above description is only a specific embodiment of the present invention, and the various examples do not limit the essential content of the present invention.

Claims

1. A three-phase signal separation method for reactive switching based on PCA algorithm and antenna array, characterized by The steps are as follows: first, the antenna array receives the radiated electromagnetic waves emitted when the reactive switching switch is turned on. Then, the signal collector amplifies and de-noises the waves and stores them in a storage module. Then, an improved PCA algorithm is used to process the measured signals to separate the three-phase arc extinguishing chamber signals of the reactive switching switch and obtain the arc extinguishing chamber signals of each phase of the reactive switching switch. The antenna is used to detect the radiated electromagnetic wave signal emitted during the operation of the reactive switching switch, convert it into a voltage signal and transmit it to the signal conditioner; The signal collector is used to realize analog-to-digital conversion of the radiated electromagnetic wave signal emitted during the operation of the reactive switching switch, and storage and display of the digital signal.

2. The method for separating three-phase signals of reactive switching switches based on PCA algorithm and antenna array according to claim 1, characterized in that The antenna is a narrowband antenna. For a three-phase reactive switching switch, at least four antennas are required. The entire array is arranged below phase A of the reactive switching switch. Three antennas face phases A, B, and C respectively, and the fourth antenna faces away from each phase of the reactive switching switch.

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