Reactive switching switch three-phase signal separation method based on NMF 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 an NMF 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 NMF algorithm to realize the signal separation of a 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 an NMF algorithm and an antenna array. Background Art

[0002] In the prior art, reactive power switching switches are numerous in power grids, playing a control and protection role. As key components in reactive power compensation equipment, reactive power switching switches operate frequently, making it easy for contacts to weld when closed and prone to severe breakdowns or even explosions when opened, seriously impacting power grid safety. The state of the arcing contacts of a reactive power switching switch directly affects its 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 state of the reactive power switching switch contacts deteriorates, the radiated electromagnetic wave signals become distorted, which can be used to diagnose and evaluate the state 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 the NMF algorithm and antenna array to achieve rapid extraction of signals from each phase arc extinguishing chamber, thereby solving the problem that the existing three-phase arc extinguishing chamber 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 of a reactive switching switch based on an NMF algorithm and an antenna array, the steps of which are as follows:

[0005] First, the antenna array is used to receive the radiated electromagnetic waves emitted when the reactive switching switch is turned on. Then, the signal collector is used to amplify and denoise the waves and store them in a storage module. The improved NMF algorithm is then 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.

[0006] 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.

[0007] 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.

[0008] 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.

[0009] The advantages of the present invention are: measuring the radiated electromagnetic waves emitted during the switching process of the reactive switching switch through an antenna array, using the antenna array to realize that the mixed signals measured by each antenna have differences in amplitude, peak occurrence time, etc., and then using the improved NMF algorithm 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 achieving 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.

[0010] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] 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.

[0012] Figure 2 FIG. 1 is a schematic diagram of an on-site antenna array arrangement according to an embodiment of the present invention.

[0013] Figure 3 This is a schematic diagram of the improved NMF algorithm of the present invention. DETAILED DESCRIPTION

[0014] See also Figure 1 A three-phase signal separation method for reactive switching switches based on the NMF algorithm and antenna array works 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 NMF 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 improve the decomposition accuracy of the traditional NMF algorithm, a feedback mechanism is introduced into non-negative matrix factorization. At each iteration, the constrained non-negative matrix factorization algorithm is first used to separate the source signals. Secondly, the correlation coefficient between the separated source signal and the mixed signal is used to measure the purity of the separated source signal. Finally, the purest separated signal is extracted and formed into a new mixed signal, thereby obtaining all the source signals one by one.

[0015] 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 NMF algorithm is used to separate the mixed signals. The antenna and the reactive switching switch are non-contact and the improved NMF 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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 NMF 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.

[0022] See also Figure 3This is the schematic diagram of the improved NMF algorithm of the present invention. Start → Stored radiated electromagnetic wave data → Remove mean → Whiten → Optimize separation matrix using gradient descent → Convergence → Estimate original signal → Calculate minimum correlation coefficients for each signal → End. Minimum → Yes → Construct new mixed signal → Remove mean. Convergence → No → Optimize separation matrix using gradient descent.

[0023] The detailed principle of the improved NMF algorithm is as follows: an arbitrary non-negative matrix V can be decomposed into the product of a non-negative matrix W and a non-negative matrix H through the improved NMF algorithm. Based on the separated results, a new mixed signal is constructed and then signal separation is performed until all signals are separated one by one. The equation is expressed as:

[0024] V=WH.

[0025] Where W is the observation matrix, W and H are factor matrices, and V∈R m×N ,W∈R m×n ,H∈R n×N , where all elements in W and H are non-negative. In actual situations, the measured signal values must be taken as absolute values to be meaningful. Here, an objective function is selected to measure the convergence degree of this algorithm, and a threshold is set. When the objective function converges to the threshold, the improved NMF algorithm is considered to be completed. The objective function is selected as:

[0026]

[0027] In the non-debt case, vol(W) is written as vol(W) = det(W T W).

[0028] J(H) is given by:

[0029] minJ(H)=||H|| 1 =∑ i,j ∣H ij ∣ 1 .

[0030] C(H) is given by:

[0031]

[0032] μ, γ, and λ are balance parameters. Solving the minimum value of the objective function can obtain the decomposition results W and H. H is the estimated result of the source signal. W and H are updated alternately by the gradient descent method. The update rules are as follows:

[0033]

[0034] in:

[0035]

[0036] in:

[0037]

[0038] The learning rate chosen here is:

[0039]

[0040] Arranging the above equations, we can obtain the multiplicative update rules of the mixing matrix W and the estimated source matrix H as follows:

[0041]

[0042] Where ε is a very small positive constant. In addition, to prevent the denominator from being equal to zero, after each iteration, the negative elements in the matrices W and H are set to zero, and the column vectors of the matrix W are normalized, that is:

[0043]

[0044] Iterate according to the above update rule until the objective function F(W,H) is less than the set threshold, thus obtaining a unique set of decomposition results W and H. For the sum of the absolute values of the correlation coefficients between the calculated source signal and the mixed signal, the corresponding separated signal with the smallest value is output as the separated source signal of this time, and a new mixed signal is formed; repeat the above steps to obtain all the source signals one by one. The specific steps are as follows:

[0045] Step 1: Use the above solution to get W=[w1,w2,...,w n ] and H=[h1,h2,...,h n ] T , let p = n.

[0046] Step 2: Select the source signal with the best separation effect and compare each separated source signal h i The combination of the absolute value of the correlation coefficient of V of the original stored signal (where i = 1, ..., p) and V is:

[0047]

[0048] Among them, v j is the jth component of the original signal V, and the minimum value is selected. The corresponding h t This is the signal with the best separation effect.

[0049] Step 3: Construct a new mixed signal: remove the source signal h from the mixed signal used for this separation t , constructing a new mixed signal V', that is, V'=Vw t ht , and let p=p-1.

[0050] Step 4: Repeat the above steps to update and iterate according to the new mixed signal V', and return to step 2 until three sets of independent arc extinguishing chamber signals are solved.

[0051] In the separation of three-phase arc extinguishing chamber signals of reactive switching switches, the three-phase mixed signal detected by the antenna array is V. The matrix H obtained by demixing V using the improved NMF algorithm is the arc extinguishing chamber signal of each phase of the reactive switching switch.

[0052] The mixed signals of the reactive switching switch obtained by the antenna array have differences in amplitude and time. The improved NMF algorithm is used to separate the mixed signals. The antenna and the reactive switching switch are non-contact and the improved NMF 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, which improves the efficiency of detection and maintenance.

[0053] 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 NMF algorithm and antenna array, characterized by The steps are as follows: First, an antenna array is used to receive the radiated electromagnetic waves emitted when the reactive switching switch is turned on. Then, a signal collector is used to amplify and denoise the waves and store them in a storage module. An improved NMF algorithm is then 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 NMF algorithm and antenna array according to claim 1 is 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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