Method and device for determining fault point in power distribution network line, storage medium, processor and program product

Abstract

The invention discloses a method and device for determining a fault point in a power distribution network line, a storage medium, a processor and a program product. The method comprises the following steps: in response to a line fault existing in a power distribution network line, obtaining an initial wave head amplitude energy spectrum density of at least one reference end in the power distribution network line; based on the initial wave head amplitude energy spectrum density, a fault branch judgment matrix is constructed and obtained, and the fault branch judgment matrix is used for representing the attenuation degree of a fault traveling wave signal in the power distribution network line from a to-be-determined fault point to a reference end; based on the fault branch judgment matrix, at least one fault branch in the power distribution network line is determined, and the fault branch is a fault branch line in the power distribution network line; and determining a fault point in the fault branch based on the traveling wave time information of the at least one reference end. According to the invention, the technical problem of low fault positioning accuracy in the power distribution network is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution networks, and in particular to a method, device, storage medium, processor and program product for determining a fault point in a power distribution network. Background Art

[0002] At present, distribution network lines are widely distributed, and the structure of distribution network lines presents the characteristics of tree-like multi-branch and multi-segment. Compared with the fault location of transmission network, the fault location method of distribution network lines is limited by the development of technical fields such as wide-area information measurement and communication, and the difficulty and complexity of implementation are much higher than that of transmission network. Therefore, there is a technical problem of low accuracy of fault location in distribution network.

[0003] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0004] Embodiments of the present invention provide a method, device, storage medium, processor and program product for determining a fault point in a distribution network line, so as to at least solve the technical problem of low accuracy of fault location in the distribution network.

[0005] According to one aspect of an embodiment of the present application, a method for determining a fault point in a distribution network line is provided, and the method may include: in response to the presence of a line fault in the distribution network line, obtaining an initial wave head amplitude energy spectral density of at least one reference end in the distribution network line; constructing a fault branch determination matrix based on the initial wave head amplitude energy spectral density, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of a fault traveling wave signal in the distribution network line when it reaches the reference end from a fault point to be determined; determining at least one fault branch in the distribution network line based on the fault branch determination matrix, wherein the fault branch is a branch line in the distribution network line where a fault exists; and determining a fault point in the fault branch based on the traveling wave time information of at least one reference end.

[0006] Optionally, based on the fault branch determination matrix, determining at least one fault branch in the distribution network line includes: using a target value to determine elements in the fault branch determination matrix to obtain the fault branch.

[0007] Optionally, the target value is used to judge the elements in the fault branch judgment matrix to obtain the fault branch, including: in response to the element corresponding to the reference end in the fault branch judgment matrix being the target value, the reference node corresponding to the reference end is determined as the fault branch node; and the branch line between the reference end and the fault branch node is determined as the fault branch.

[0008] Optionally, based on the initial wave head amplitude energy spectrum density, a fault branch decision matrix is ​​constructed, including: obtaining the standard wave head amplitude energy spectrum density corresponding to the reference end under the simulated fault state; based on the standard wave head amplitude energy spectrum density and the initial wave head amplitude energy spectrum density, a fault branch decision matrix is ​​constructed.

[0009] Optionally, obtaining the standard wave head amplitude energy spectral density corresponding to the reference end under a simulated fault state includes: determining at least one reference end in the distribution network line before a line fault occurs in the distribution network line; determining a reference node corresponding to the reference end; performing a simulated fault test on the reference node to obtain the standard wave head amplitude energy spectral density.

[0010] Optionally, determining a fault point in a fault branch based on traveling wave time information of at least one reference end includes: obtaining a distance between the fault point to be determined and a fault branch node in the fault branch based on the traveling wave time information; and determining the fault point in the fault branch based on the distance.

[0011] According to another aspect of an embodiment of the present application, a device for determining a fault point in a distribution network line is also provided, and the device may include: an acquisition unit, used to acquire an initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line in response to a line fault in the distribution network line; a construction unit, used to construct a fault branch determination matrix based on the initial wave head amplitude energy spectrum density, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; a first determination unit, used to determine at least one fault branch in the distribution network line based on the fault branch determination matrix, wherein the fault branch is a branch line in the distribution network line where a fault exists; and a second determination unit, used to determine the fault point in the fault branch based on the traveling wave time information of at least one reference end.

[0012] According to another aspect of an embodiment of the present application, a computer-readable storage medium is also provided, which includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute the method for determining the fault point in the distribution network line of an embodiment of the present application.

[0013] According to another aspect of an embodiment of the present application, a processor is further provided, the processor being used to run a program, wherein when the program is run by the processor, the method for determining a fault point in a distribution network line of an embodiment of the present application is executed.

[0014] According to another aspect of an embodiment of the present application, a computer program product is further provided, the computer program product comprising computer instructions, wherein the computer instructions, when executed by a processor, implement the method for determining a fault point in a distribution network line of an embodiment of the present application.

[0015] In an embodiment of the present application, in response to a line fault in a distribution network line, the initial wave head amplitude energy spectral density of at least one reference end in the distribution network line is obtained; based on the initial wave head amplitude energy spectral density, a fault branch determination matrix is ​​constructed, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; based on the fault branch determination matrix, at least one fault branch in the distribution network line is determined, wherein the fault branch is a branch line with a fault in the distribution network line; based on the traveling wave time information of at least one reference end, the fault point in the fault branch is determined. That is, in an embodiment of the present application, the initial wave head amplitude energy spectral density in the distribution network line is first obtained, and based on the initial wave head amplitude energy spectral density, a fault branch determination matrix can be constructed, and based on the fault branch determination matrix, the fault branch is determined. After determining the fault branch, the fault point in the fault branch can be determined based on the traveling wave time information of the reference end, thereby solving the technical problem of low accuracy of fault location in the distribution network and achieving the technical effect of improving the accuracy of fault location in the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1 is a flow chart of a method for determining a fault point in a distribution network line according to an embodiment of the present application;

[0018] Figure 2 is a schematic diagram of a distribution network topology structure according to an embodiment of the present application;

[0019] Figure 3 is a schematic diagram of a T-shaped branch line according to an embodiment of the present application;

[0020] Figure 4 is a schematic diagram of a multi-branch power grid line simulation model according to an embodiment of the present application;

[0021] Figure 5 is a schematic diagram of energy spectrum density distribution of fault traveling wave amplitudes at different reference ends according to an embodiment of the present application;

[0022] Figure 6 It is a schematic diagram of the reference end first wave head arrival time calibration when F1 fails according to an embodiment of the present application;

[0023] Figure 7 is a schematic diagram of accurate positioning of a fault point based on a reference end according to an embodiment of the present application;

[0024] Figure 8 is a flow chart of a fault location method according to an embodiment of the present application;

[0025] Fig. 9 is a schematic diagram of a device for determining a fault point in a distribution network line according to an embodiment of the present application;

[0026] Fig.10 is a structural block diagram of a computer terminal according to an embodiment of the present application;

[0027] Fig.11 It is a block diagram of an electronic device for a method for determining a fault point in a distribution network line according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] According to an embodiment of the present application, an embodiment of a method for determining a fault point in a distribution network line is provided. The steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0031] In this embodiment, a method for determining a fault point in a distribution network line is proposed. The method can first obtain the initial wave head amplitude energy spectrum density in the distribution network line, and based on the initial wave head amplitude energy spectrum density, a fault branch determination matrix can be constructed. Based on the fault branch determination matrix, the fault branch can be determined. After the fault branch is determined, the fault point in the fault branch can be determined based on the traveling wave time information of the reference end, thereby solving the technical problem of low accuracy of fault location in the distribution network and achieving the technical effect of improving the accuracy of fault location in the distribution network.

[0032] Figure 1 FIG. 1 is a flow chart of a method for determining a fault point in a distribution network according to an embodiment of the present application. Figure 1 As shown, the method may include the following steps:

[0033] Step S102, in response to a line fault in the distribution network line, obtaining an initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line.

[0034] In the technical solution provided in the above step S102 of the present application, the above initial wave head amplitude energy spectrum density may be the first wave head amplitude energy spectrum density, which may be the first wave head amplitude energy spectrum density monitored under a real fault in the distribution network line.

[0035] Optionally, the energy spectrum density of the first wave head amplitude of the initial traveling wave is related to the distance to the fault point.

[0036] Optionally, after a real fault occurs in the distribution network line, the time-frequency analysis method (such as S transform, wavelet transform, etc.) can be used to extract the initial traveling wave head amplitude energy spectral density Eif detected by each reference end. At the same time, based on the initial traveling wave head amplitude energy spectral density, the fault traveling wave head arrival time can be calibrated and the fault branch judgment matrix can be constructed. The above-mentioned traveling wave time information can be the time when the wave head of the traveling wave signal reaches the reference end, that is, the arrival time.

[0037] Optionally, in a power system, when a distribution network line fails (such as a short circuit), a fast-propagating electromagnetic wave is generated at the fault point, called a traveling wave signal (referred to as a traveling wave), which can be used to quickly transmit fault information. The initial part of the traveling wave signal can be a wave head, that is, the 'front edge' of the traveling wave, which usually has a higher frequency component and energy. The characteristics of the wave head (such as arrival time, amplitude and frequency distribution) can be key information for fault location.

[0038] Optionally, through spectrum analysis, a spectrum diagram of the traveling wave signal can be obtained, in which the amplitude of each frequency point can represent the intensity of the frequency component in the signal. The amplitude energy spectral density is the energy distribution of the signal at each frequency, which reflects the energy characteristics of the signal in the frequency domain. For traveling wave signals, the amplitude energy spectral density of the wave head can be used to determine the fault distance and type. Therefore, the initial wave head amplitude energy spectral density can be obtained, and the initial wave head amplitude energy spectral density can be used to locate the fault point in the distribution network line.

[0039] Optionally, since the traveling wave is affected by line parameters (such as wave impedance and length) during propagation, the amplitude and energy of the wave head will decay with increasing distance. Therefore, by comparing the wave head amplitude energy spectral density measured by the traveling wave detection devices at different positions, the energy change when the traveling wave reaches each detection point (that is, the reference end) can be calculated, and then the distance relationship between the fault point and each reference end can be inferred.

[0040] For example, you can use Japanese style Solve the column norm of the amplitude energy spectral density matrix to extract the amplitude energy spectral density of the traveling wave head, where Performing S transformation results in a two-dimensional time-frequency matrix A, where the columns correspond to the sampling point time and the rows correspond to the frequency value. The matrix elements are complex numbers, and the amplitude and phase information can be obtained from the matrix elements. Furthermore, the modulus value of each element in the A matrix can be calculated to obtain the modulus time-frequency matrix D; then the square of each element in the modulus time-frequency matrix can be obtained to obtain the signal amplitude energy spectrum density E(g,l) at the lth sampling time at the gth frequency, which is E(g,l)=D 2 (g,l). Where N is the number of sampling points. T is the sampling time interval. k is a discrete time point, k = 1, 2...N-1. n is a frequency sampling point, n = 1, 2,..., N / 2. E gl It can be expressed as finding among all possible values ​​of l that E l The largest l value, that is, the position where the maximum amplitude occurs. The time point corresponding to this position can be the arrival time of the wave head. The signal amplitude energy spectral density E(g,l) at the lth sampling time under the gth frequency. E l It can be used to represent the amplitude of the lth sampling point of the signal. Hf The energy spectral density of the initial traveling wave head amplitude at the fault point can be used to detect the real fault.

[0041] Optionally, the value of the column norm is defined as the initial traveling wave head amplitude energy spectral density, and the corresponding sampling time is the arrival time of the traveling wave head. That is, while extracting the initial traveling wave head amplitude energy spectral density, the wave head arrival time is calibrated to obtain the traveling wave time information, which can be used to determine the location of the fault point.

[0042] Optionally, the sampling time can be determined based on the extraction of the amplitude energy spectrum density of the head of the traveling wave. That is, the amplitude energy spectrum density of the head of the traveling wave can be extracted by solving the column norm of the amplitude energy spectrum density matrix, and the value of the obtained column norm is defined as the initial amplitude energy spectrum density of the head of the traveling wave. The sampling time corresponding to the value of this column norm is the arrival time of the head of the traveling wave. This process is carried out while extracting the amplitude energy spectrum density of the head of the initial traveling wave, that is, the arrival time of the head can be calibrated by this method. Among them, E(g,l) can be used to indicate finding the l value that makes El the largest among all possible l values, that is, the position where the maximum amplitude appears, and the time point corresponding to this position is the arrival time of the head of the traveling wave.

[0043] Step S104, constructing a fault branch determination matrix based on the initial wave head amplitude energy spectral density, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined.

[0044] In the technical solution provided in the above step S104 of the present application, a fault branch determination matrix can be constructed based on the initial wave head amplitude energy spectral density. The above fault branch determination matrix can be constructed by comparing the fault wave head amplitude energy spectral density detected by different reference ends with the reference value obtained when simulating the fault, and the elements in the fault branch determination matrix can be used to reflect the positional relationship of the fault point relative to each reference end and the reference node.

[0045] Optionally, since the attenuation of the traveling wave signal during propagation is related to the distance from the fault point to the reference end, the element value in the fault branch determination matrix can reflect the attenuation degree of the fault traveling wave when it reaches different reference ends from the fault point. Generally, the traveling wave signal has a smaller attenuation when it reaches the reference end closer to the fault point, and a larger attenuation when it reaches the reference end farther away.

[0046] Step S106, based on the fault branch determination matrix, determining at least one fault branch in the distribution network line, wherein the fault branch is a branch line in the distribution network line where a fault exists.

[0047] In the technical solution provided in the above step S106 of the present application, the fault branch determination matrix can be judged based on the target value or the preset determination rule to determine at least one fault branch in the distribution network line. The above target value can be a preset value, for example, it can be 1. The above determination rule can be a preset rule, or a rule for judging the elements in the fault branch determination matrix. It should be noted that this is only an example, and any method for determining the fault branch based on the fault branch determination matrix should be within the protection scope of the present application, and no specific limitation is made here.

[0048] For example, constructing a fault branch determination matrix may include the following steps: installing traveling wave detection devices at the end of the main feeder and each branch of the distribution network, and defining the reference nodes corresponding to these detection devices. These nodes are usually subjected to fault simulation under normal operating conditions to extract the baseline characteristics of the traveling wave signal. A simulated fault setting is performed at each reference node, and the energy spectrum density of the first wave head amplitude (denoted as (E_{ij})) of the initial traveling wave signal is extracted at the corresponding reference end using S transform (or other spectrum analysis techniques). These values ​​are used as a benchmark for subsequent comparison and analysis when no real fault occurs. When a real fault occurs in the distribution network, the traveling wave detection device can detect and extract the energy spectrum density of the first wave head amplitude (denoted as (E_{if})) of the fault traveling wave signal in real time at each reference end. Using the characteristics of the traveling wave signal before and after the fault, a fault branch determination matrix (denoted as (M)) can be constructed. The elements of the matrix (M) are usually expressed as (M_{i,j}), and the calculation formula of the element can be: [M_{i,j}=\frac{E_{ij}}{E_{if}}. Among them, (i) can be used to represent the reference end, and (j) can be used to represent the reference node. Through the above formula, (M_{i,j}) can be used to reflect the comparison between the real fault and the simulated fault in the traveling wave signal characteristics. Furthermore, the element values ​​in the constructed fault branch judgment matrix (M) can be analyzed, and the fault branch where the fault occurs can be judged according to its change characteristics.

[0049] Optionally, if the column elements (M_{i,j}) corresponding to a certain reference end in the matrix are all equal to 1, this usually indicates that the fault occurs near the reference node corresponding to the reference end. If a column element (M_{i,j}) is less than 1 and is located in a single-branch line, it can be determined that there is a fault in the branch line. If a column element (M_{i,j}) is less than 1 and is located in a multi-branch node line, but the element values ​​corresponding to its lower-level reference nodes are all greater than 1, this may indicate that the fault occurs on the last-level branch of the multi-branch node. If some of the element values ​​in the matrix are less than 1 and some are greater than 1, this usually indicates that the fault occurs between the upper and lower reference nodes of the multi-branch node. If all element values ​​in the matrix are greater than 1, this may mean that the fault occurs between the branch nodes of the main feeder. At this time, it may be necessary to construct an auxiliary judgment matrix for further analysis.

[0050] Optionally, considering the possible errors and interferences in the actual measurement, an error margin may be introduced on the basis of the calculated matrix element values ​​for correction to improve the accuracy and reliability of the determination.

[0051] Step S108, determining a fault point in the fault branch based on the traveling wave time information corresponding to at least one reference end.

[0052] In the technical solution provided in the above step S108 of the present application, after the fault branch is determined, the position of the fault point in the fault branch can be determined based on the traveling wave time information corresponding to the reference end to complete the precise positioning of the fault point.

[0053] In this embodiment, the traveling wave amplitude differential amplification mechanism is used to locate the multi-branch power grid fault. The method extracts the energy spectrum density of the initial traveling wave head amplitude of the fault, establishes a fault branch determination matrix, and after accurately determining the fault branch, the fault location can be locked according to the double-end traveling wave principle.

[0054] Optionally, by installing a traveling wave detection device based on an integrated capacitive coupler at each branch node of the distribution network, the energy spectrum density of the initial wave head amplitude of the fault traveling wave signal can be extracted in real time. The characteristic that the initial traveling wave head amplitude is inversely proportional to the fault distance is used to construct a fault branch judgment matrix, and the fault branch is judged based on the change characteristics of the matrix elements. At the same time, a method for accurately locating the fault point based on three-terminal time information is proposed. By screening the traveling wave time information of the three reference ends with the smallest amplitude attenuation, a group of equations about the traveling wave velocity and arrival time is established to eliminate the influence of the traveling wave velocity on the fault location, thereby achieving accurate positioning of the fault point.

[0055] Through the above steps S102 and S108 of the present application, in response to the existence of a line fault in the distribution network line, the initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line is obtained; based on the initial wave head amplitude energy spectrum density, a fault branch determination matrix is ​​constructed, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; based on the fault branch determination matrix, at least one fault branch in the distribution network line is determined, wherein the fault branch is a branch line with a fault in the distribution network line; based on the traveling wave time information of at least one reference end, the fault point in the fault branch is determined. That is to say, in the embodiment of the present application, the initial wave head amplitude energy spectrum density in the distribution network line is first obtained, and based on the initial wave head amplitude energy spectrum density, a fault branch determination matrix can be constructed, and based on the fault branch determination matrix, the fault branch is determined. After determining the fault branch, the fault point in the fault branch can be determined based on the traveling wave time information of the reference end, thereby solving the technical problem of low accuracy of fault location in the distribution network and achieving the technical effect of improving the accuracy of fault location in the distribution network.

[0056] The above method of this embodiment is further introduced below.

[0057] As an optional implementation, step S106, based on the fault branch determination matrix, determines at least one fault branch in the distribution network line, including: using the target value to determine the elements in the fault branch determination matrix to obtain the fault branch.

[0058] In this embodiment, the target value may be 1. After the fault branch determination matrix is ​​obtained, the elements in the fault branch determination matrix may be determined based on the target value to obtain the fault branch.

[0059] Optionally, for the single branch line fault criterion, Figure 2 is a schematic diagram of a distribution network topology structure according to an embodiment of the present application, such as Figure 2 As shown, in the distribution network line, AH is a main feeder with multiple branch nodes, and ae is a branch node of each branch. A traveling wave detection device can be installed at each branch node, and the traveling wave detection device can be used to obtain the initial wave head amplitude energy spectrum density.

[0060] Optionally, when a line fault in the distribution network line occurs Figure 2 At point d3 in the d For example, the distance from the reference end H to the fault point d3 is less than the distance from the reference end H to its corresponding reference node d. Therefore, the energy spectrum density E of the first wave amplitude detected by the real fault Hf Will be greater than the E obtained when simulating a fault Hd(That is, the standard wave head amplitude energy spectral density). At the same time, the distances from other reference ends to point d3 are all greater than the distances from other reference ends to their corresponding reference nodes, that is, the standard wave head amplitude energy spectral density E obtained by simulating faults at other reference ends ij are greater than the initial wave head amplitude energy spectral density E detected when each reference end has a real fault if At this time, the fault branch determination matrix

[0061]

[0062] The array can be:

[0063] According to the characteristics of the elements in the above formula, when a branch line of a single branch node fails, the value of the element in the reference end column corresponding to the branch where the fault occurs is less than 1. Therefore, in the process of judging the fault branch determination matrix, if it is determined that there is an element in the fault branch determination matrix that is less than the target value (that is, 1), it can be determined that the reference end corresponding to the element is an abnormal end, and then the reference end (such as H) and the reference node corresponding to the reference end (such as d) can be determined as a fault branch node. Further, the branch line between the reference end and the fault branch node can be determined as a fault branch.

[0064] Optionally, Figure 2 For example, the reference node of reference ends A and B is a; the reference node of G and H is d; the reference node of D is c. It should be noted that: when there are multiple branch nodes in the branch line (such as there are two branch nodes b and e on the Cb branch), the branch nodes b and e can be classified as reference nodes of the C and F ends, and the node b connected to the main feeder is defined as the upper reference node, and the node e connected to the bc branch is defined as its lower reference node. If the Fe branch contains other branches, the reference nodes are recursively defined in the above manner, and the corresponding column elements are added to the branch determination matrix in the upper and lower order. At the same time, the energy spectrum density of the first wave head amplitude of the initial traveling wave is related to the distance to the fault point. When the line topology and the installation position of the traveling wave detection device are known, the shortest path length from each reference node to the reference end is certain, that is, when each reference node fails, the energy spectrum density of the first wave head amplitude of the initial traveling wave extracted by the reference end is fixed. The elements in the matrix are the energy spectrum density E of the initial wave head amplitude collected under real faults. if And the standard wave head amplitude energy spectral density E collected under simulated fault ij The ratio between the two, such as Figure 2 As shown in Figure 2, when d3 fails, only the energy spectrum density of the real fault first wave head amplitude at the reference end H is smaller than that of the simulated fault, so only the element corresponding to H is less than 1.

[0065] For example, when a fault occurs in Figure 2When the fault occurs at point d5 in the last branch line, the distance from the reference end F to the fault point d5 is smaller than the distance to the reference nodes e and b. Therefore, the energy spectrum density E of the first wave head amplitude detected by the real fault is Ff Will be greater than E obtained by simulating faults Fb and E Fe , it can be seen that when the column elements of the reference node corresponding to a reference end in the matrix are all less than 1, the distribution network fault occurs in the last branch line corresponding to the reference end. At this time, the fault branch decision matrix (M) can be:

[0066]

[0067] Optionally, when a fault occurs in Figure 2 When the fault occurs at point d4 in the multi-branch line, the fault occurs between nodes. For reference terminals C and F, the distance from reference terminals F and C to the fault point d3 is less than the distance to reference node e, and the distance from reference node b is greater than the distance to the fault point d3. Therefore, the energy spectrum density E of the first wave amplitude detected by the real fault is Cf and E Ff will be greater than the E calculated offline Cb and E fb , but less than E Ce and E fe It can be seen that the column elements corresponding to the upper reference node are less than 1, and the column elements corresponding to the lower reference node are greater than 1. Therefore, it can be determined that the fault occurs between the two upper and lower reference nodes on the multi-branch line. At this time, the fault branch determination matrix can be:

[0068]

[0069] Optionally, after obtaining the fault judgment matrix, if there is a column element corresponding to the upper reference node in the fault judgment matrix that is less than 1, and a column element corresponding to the lower reference node that is greater than 1, it can be determined that the fault occurs between the two upper and lower reference nodes on the multi-branch line, that is, it can be determined that the fault occurs between reference node e and reference node b.

[0070] Optionally, if there is an element in the matrix that is less than 1 and is located in a single branch line, it can be determined that a fault occurs in the branch line.

[0071] Optionally, a judgment rule (also called judgment basis, or fault judgment criterion) can be determined in advance, and the judgment rule is related to the target value. The judgment rule can be: if the elements less than 1 in the fault branch judgment matrix are located in the multi-branch node line, and the element values ​​corresponding to the reference end are all less than 1, it is the last level branch fault of the multi-branch node line; if some of the element values ​​corresponding to the reference end are less than 1, and some are greater than 1, then according to the difference in element characteristics corresponding to the upper and lower reference points of the fault point, the fault between the upper and lower reference nodes of the multi-branch node line can be determined. After obtaining the fault branch judgment matrix, the fault branch judgment matrix can be judged according to the judgment rule to determine the fault branch in the distribution network line.

[0072] Optionally, when a fault occurs in Figure 2 When the distance from each reference end to its corresponding reference node is less than the distance from each reference end to point d1, the energy spectrum density E of the first wave amplitude detected by the real fault is if Both are smaller than the E obtained when simulating faults. ij , at this time the fault branch decision matrix can be:

[0073]

[0074] Optionally, according to the characteristics of the elements in the above-mentioned fault branch judgment matrix, when a fault occurs between the main feeder nodes, the values ​​of all reference end elements in the matrix are greater than 1. Therefore, the fault judgment criterion between the main line nodes can be: if the values ​​of all reference end elements in the matrix are greater than 1, it can be determined that a fault occurs between the main feeder nodes.

[0075] Optionally, if all elements in the fault branch determination matrix are greater than 1, it can be determined that the fault is between the reference nodes of the main feeder. An auxiliary fault branch determination matrix can be constructed. According to the element characteristics corresponding to the reference nodes on the left and right sides of the fault point, the fault between the main feeder branch nodes can be determined.

[0076] Optionally, since the fault branch determination matrix M can only determine that the fault occurs between the reference nodes, but cannot accurately locate which two reference nodes from a to d have the fault, a fault branch auxiliary determination matrix K can be constructed:

[0077]

[0078] Among them, the energy spectrum density of the initial traveling wave head amplitude detected by the reference end H is E Hj . J corresponds to reference nodes a to d. E Hf The energy spectral density of the initial traveling wave head amplitude at the fault point detected for the real fault.

[0079] Optionally, when simulating a node fault on the main feeder, assume that the energy spectrum density of the initial traveling wave head amplitude detected by the reference end H is E Hj The energy spectrum density of the initial traveling wave head amplitude when the real fault is detected at the fault point is E Hf As in the previous article, when the reference node on the right side of the fault point fails, the distance from each reference node to the reference end H is shorter than the distance from the fault point to the reference end H, while when the reference node on the left side of the fault point fails, the situation is just the opposite.

[0080] Optionally, considering that there may be various factors affecting the process of extracting the energy spectrum density of the initial traveling wave head amplitude, the calculated values ​​of the elements in the matrices M and K may deviate from the actual values. Therefore, a certain margin is required to correct the error interference. Assume that the calculated value of a certain element in the matrices M and K is α, and the margin is γ. When actually calculating the fault branch judgment matrix, the values ​​of each element in the matrix are corrected according to the following situations: when "1-γ≤α≤1+γ", correct α=1; when "α<1-γ", correct α<1; when "α>1+γ", correct α>1.

[0081] According to experience, the error margin γ value can be set to 0.005. It should be noted that this is only an example, and the size of the error margin can be selected according to actual conditions.

[0082] As an optional implementation, the target value is used to judge the elements in the fault branch judgment matrix to obtain the fault branch, including: in response to the element corresponding to the reference end in the fault branch judgment matrix being the target value, the reference node corresponding to the reference end is determined as the fault branch node; the branch line between the reference end and the fault branch node is determined as the fault branch.

[0083] In this embodiment, judging the fault branch determination matrix based on the target value may include the following parts: if the element corresponding to the reference end is the target value, the reference node corresponding to the reference segment may be determined as the fault branch node, and the branch containing the fault branch node may be determined as the fault branch.

[0084] Optionally, after obtaining the fault branch determination matrix, the elements in the fault branch determination matrix may be analyzed. If there is an element in the matrix equal to a target value (eg, 1), it may be determined that a reference node corresponding to the reference end has a fault.

[0085] For example, when a fault occurs in Figure 2 When the fault point d2 is detected, the distance from the reference end H to the fault point d2 is equal to the distance from the reference end H to its corresponding reference node d. Therefore, the energy spectrum density E of the first wave amplitude detected by the real fault Hf will be equal to E obtained when simulating a fault HdFrom the above, we can see that the energy spectrum density E of the first wave amplitude detected by the real fault Gf will be equal to E obtained when simulating a fault Gd , and the energy spectral density E of the first wave amplitude calculated offline at the other reference ends ij are all smaller than the initial traveling wave amplitude energy spectral density E detected when each reference end has a real fault if At this time, the fault branch decision matrix can be:

[0086]

[0087] According to the characteristics of the elements in M, when a branch node fails, the value of the element in the reference end column corresponding to the faulty branch node is equal to 1. Therefore, after obtaining the faulty branch determination matrix, it can be determined whether there is an element with an element value of 1 in the faulty branch node. If so, the reference point corresponding to the reference end corresponding to the element can be determined as the faulty branch node, and the branch line between the reference end and the faulty branch node can be determined as the faulty branch. For example, it can be determined Figure 2 Hd in is the fault branch.

[0088] Optionally, the elements in the fault branch decision matrix may be represented by M(i, j).

[0089] As an optional implementation, step S104, based on the initial wave head amplitude energy spectrum density, constructs a fault branch judgment matrix, including: obtaining the standard wave head amplitude energy spectrum density corresponding to the reference end under the simulated fault state; based on the standard wave head amplitude energy spectrum density and the initial wave head amplitude energy spectrum density, constructs a fault branch judgment matrix.

[0090] In this embodiment, the energy spectrum density of the standard wave head amplitude fault branch judgment matrix corresponding to the reference end under the simulated fault state can be obtained. Based on the standard wave head amplitude energy spectrum density and the initial wave head amplitude energy spectrum density, a fault branch judgment matrix can be constructed. For example, the quotient between the standard wave head amplitude energy spectrum density and the initial wave head amplitude energy spectrum density can be determined as an element in the fault branch judgment matrix.

[0091] Optionally, the standard wave front amplitude energy spectral density may be a first wave front amplitude energy spectral density obtained under a simulated fault state.

[0092] Optionally, the standard wave head amplitude energy spectral density of the reference end under the simulated fault can be obtained in advance. In response to the presence of a line fault in the distribution network line, the initial wave head amplitude energy spectral density of the reference end in the distribution network line under the real fault can be obtained. The quotient between the standard wave head amplitude energy spectral density and the initial wave head amplitude energy spectral density corresponding to the same reference end can be determined, and the quotient can be determined as the element corresponding to the reference end. The above method can be used to obtain the element of at least one reference end in the fault branch determination matrix, thereby obtaining the element in the fault branch determination matrix.

[0093] As an optional implementation, obtaining the standard wave head amplitude energy spectrum density corresponding to the reference end under a simulated fault state includes: before a line fault occurs in the distribution network line, determining at least one reference end in the distribution network line; determining the reference node corresponding to the reference end; performing a simulated fault test on the reference node to obtain the standard wave head amplitude energy spectrum density.

[0094] In this embodiment, before a line fault occurs in the distribution network line, at least one reference end in the distribution network line and a reference node corresponding to the reference end can be predetermined, and a traveling wave detection device based on an integrated capacitive coupler can be installed at the reference end. The device can be used to monitor the initial wave head amplitude energy spectrum density and the standard wave head amplitude energy spectrum density of the reference end.

[0095] Optionally, a traveling wave detection device based on an integrated capacitor coupler is installed at the end of a multi-branch distribution line, and a reference end and a reference node corresponding to the reference end are defined. Furthermore, in order to make the integrated capacitor coupler more suitable for the detection of traveling waves of distribution network faults, the capacitance value of its coupling capacitor and tuner can be reduced during design, and the resistance value of the sampling resistor can be increased when obtaining the secondary side output signal, so as to improve its amplitude-frequency characteristics and detection sensitivity in the high frequency band, and realize high-precision monitoring and sensitive perception of the initial fault state.

[0096] Optionally, before a real fault occurs, a simulated fault can be set at each reference node (a to d), and the initial traveling wave head amplitude energy spectrum density Eij can be extracted at the corresponding reference end using S transformation to obtain the standard wave head amplitude energy spectrum density under the simulated fault state.

[0097] For example, Figure 2For example, the reference node corresponding to the reference end can be set in advance, for example, the reference node of reference end A and reference end B can be set as a in advance; the reference node of reference end G and reference end H can be set as d; the reference node of reference end D can be set as c. It should be noted that: when there are multiple nodes in the branch line (such as there are two nodes b and e on the Cb branch), the branch nodes b and e need to be classified as reference nodes of the C and F ends, and the node b connected to the main feeder is defined as the upper reference node, and the node e connected to the bc branch is defined as its lower reference node. If the Fe branch contains other branches, the reference node is recursively defined in the above manner, and the corresponding column elements are added in the branch decision matrix in the upper and lower order. Furthermore, the reference node can be subjected to a simulated fault test to obtain the standard wave head amplitude energy spectrum density corresponding to the reference end under the simulated fault test.

[0098] As an optional implementation, step S104, based on the traveling wave time information corresponding to at least one reference end, determines the fault point in the fault branch, including: based on the traveling wave time information, obtaining the distance between the fault point to be determined and the fault branch node in the fault branch; based on the distance, determining the fault point in the fault branch.

[0099] In this embodiment, after the fault branch is determined, the location of the fault point in the distribution network line may be further determined.

[0100] Optionally, determining the fault point may include the following: selecting the top three reference ends with the highest amplitude, using the time information of the three reference ends to determine the output fault distance, thereby determining the position of the fault point and achieving accurate positioning of the fault position.

[0101] For example, accurate fault location may include: based on the energy spectrum density of the initial traveling wave head amplitude extracted during the actual fault, three reference ends with the smallest initial traveling wave amplitude attenuation may be selected. The wave head time information of the traveling waves of the three reference ends may be used for fault location to determine the exact location of the fault point.

[0102] Figure 3 is a schematic diagram of a T-type branch line according to an embodiment of the present application, Figure 3 Taking the fault of the T-type branch line shown as an example, a group of equations about the traveling wave velocity and the traveling wave arrival time can be established to eliminate the influence of the traveling wave velocity on the fault point location.

[0103] According to the three reference end travel time information (can be referred to as travel time), the following equations can be established:

[0104]

[0105] Among them, t0 can be the time when the fault occurs, t1, t2 and tn They can be the moments when the head of the traveling wave reaches the corresponding reference end respectively; v can be the wave velocity of the line mode traveling wave. The distance between E1 and point a. Fa It can be the distance between F and point a. It can be the distance between En and point a. It can be the distance between E2 and point a.

[0106] Alternatively, by solving the above equations, the fault distance expression can be obtained:

[0107]

[0108] Optionally, according to the above formula, the distance from the reference end to the fault point can be calculated. According to this example, the position of the fault point (ie, point F) can be accurately determined.

[0109] It can be seen from the formula that this method does not need to know the fault occurrence time and the speed of the fault traveling wave, and is suitable for different fault types. By comparing the energy spectral density of the initial fault traveling wave head amplitude, the time information of the three reference ends with the smallest traveling wave amplitude attenuation is selected and substituted into the above formula, which can effectively avoid the problem of fault location loss caused by the use of traveling waves with severe attenuation.

[0110] In the embodiment of the present application, the initial wave head amplitude energy spectral density in the distribution network line is first obtained, and based on the initial wave head amplitude energy spectral density, a fault branch determination matrix can be constructed, and based on the fault branch determination matrix, the fault branch is determined. After the fault branch is determined, the fault point in the fault branch can be determined based on the traveling wave time information of the reference end, thereby solving the technical problem of low accuracy of fault location in the distribution network and achieving the technical effect of improving the accuracy of fault location in the distribution network.

[0111] The above method of the present application is described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the present application is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of the present application fall within the protection scope of the present application.

[0112] At present, the distribution network lines are widely distributed, and the structure is tree-like with multiple branches and segments. Compared with the fault location of the transmission network, the fault location method of the distribution network is limited by the development of wide-area information measurement, communication and other technical fields, and the difficulty and complexity of implementation are much higher than that of the transmission network.

[0113] In the related art, the fault traveling wave location method of the distribution network may include: single-end traveling wave method, double-end traveling wave method and multi-end traveling wave method. Among them, the single-end traveling wave method uses the arrival time difference between the first wave head and the reflected wave head of the fault point to perform fault distance measurement. However, there are many discontinuous points in the wave impedance of the distribution network, and the fault traveling wave will produce refraction and reflection after passing through any discontinuous point. Therefore, it is extremely difficult to accurately identify the reflected wave head of the fault point, which makes the traditional single-end traveling wave method difficult to apply to the actual distribution network. Compared with the single-end traveling wave method, the traditional double-end traveling wave method uses the arrival time of the first wave head of the fault traveling wave at the two observation points to perform fault distance measurement, without the need to identify the reflected wave at the fault point, and is more suitable for fault location in the distribution network. However, the double-end traveling wave method requires time synchronization of the observation points at both ends. When the time error at both ends is large, the accuracy of its fault distance measurement will be greatly reduced. In addition, due to the topological structure characteristics of the distribution network with multiple branches and line-cable hybrid, it is difficult to achieve accurate fault location of multi-branch distribution networks regardless of the traditional single-end traveling wave method or the double-end traveling wave method.

[0114] In summary, the existing distribution network fault location methods, in most cases, fail to fully consider the influence of factors such as fault traveling wave arrival time error, traveling wave velocity, line parameter differences and multi-branch structure. There are problems such as difficulty in fault branch determination, inaccurate fault location accuracy and insufficient fault tolerance of the location method. Therefore, it is very important to study a fault location method that can effectively reduce the influence of line structure, wave head arrival time error and traveling wave velocity on the location results.

[0115] In view of the fact that the existing multi-branch distribution line fault location method is affected by the initial traveling wave arrival time error and the traveling wave velocity, there are problems such as complex fault branch determination and insufficient fault location accuracy. In this embodiment, a multi-branch distribution network fault location method based on the traveling wave amplitude differential amplification mechanism is proposed, which greatly improves the fault location accuracy.

[0116] Optionally, first, the method can extract the energy spectral density of the amplitude of the head of the initial traveling wave of the fault, establish a fault branch judgment matrix, and after accurately judging the fault branch, the fault position can be locked according to the double-end traveling wave principle. That is, by installing a traveling wave detection device based on an integrated capacitive coupler at each branch node of the distribution network, the energy spectral density of the initial wave head amplitude of the fault traveling wave signal can be extracted in real time. By using the characteristic that the amplitude of the initial traveling wave head is inversely proportional to the fault distance, a fault branch judgment matrix is ​​constructed, and the fault branch is judged according to the change characteristics of the matrix elements. At the same time, a method for accurately locating the fault point based on three-terminal time information is proposed. By screening the traveling wave time information of the three reference ends with the smallest amplitude attenuation, a group of equations about the traveling wave velocity and arrival time is established to eliminate the influence of the traveling wave velocity on the fault location, thereby achieving accurate positioning of the fault point.

[0117] The following are specific application examples of this solution.

[0118] In this embodiment, simulation software (eg, PSCAD / EMTDC) may be used to verify the proposed fault location method. Figure 4 is a schematic diagram of a multi-branch power grid line simulation model according to an embodiment of the present application, such as Figure 4 As shown, a multi-branch distribution network line simulation model can be built, and the distribution network terminals A to H are defined as reference terminals, and each reference terminal is equipped with a traveling wave detection device based on an integrated capacitive coupler. Among them, the reference node of reference terminal A and reference terminal B is a, the reference node of reference terminal H and reference terminal G is d, the reference nodes of reference terminal C and reference terminal F are e and b, and the reference node of reference terminal D is c. The sampling frequency of the above-mentioned traveling wave detection device can be set to 1 megahertz (MHz), and the time window data of 1 millisecond (ms) can be taken for fault location.

[0119] Optionally, to verify the effectiveness of the proposed fault location method, fault points F1, F2, and F3 can be set at branch nodes a, b, and e, respectively; fault point F4 can be set at a distance of 4 km from branch bc to node b, and fault point F5 can be set at a distance of 2 km from branch be to node b; and fault point F6 can be set at a distance of 3 km from branch Fe to end F. All fault point parameters are A-phase grounding fault, transition resistance 50 ohms, and fault initial phase angle 45 degrees.

[0120] Optionally, Figure 5 is a schematic diagram of energy spectrum density distribution of fault traveling wave amplitudes at different reference ends according to an embodiment of the present application, such as Figure 5 As shown, before a real fault occurs, the energy spectrum density of the reference initial traveling wave head amplitude at each reference end can be extracted.

[0121] Table 1 Energy spectrum density of the first wave head amplitude of the initial fault traveling wave detected at each reference end

[0122]

[0123]

[0124] Optionally, Table 1 is a table of energy spectrum density of the amplitude of the initial traveling wave head of the fault detected by each reference end. As shown in Table 1, Figure 4 The six fault points in the simulation model are simulated separately, and the S transform is used to extract the energy spectrum density of the amplitude of the initial traveling wave of the fault.

[0125] Optionally, when the reference node a of the main feeder fails, Figure 5In the above equation, the energy spectrum density of the initial wave head amplitude of the reference fault extracted from the corresponding reference end when each reference node simulates a fault, and the energy spectrum density of the initial wave head amplitude of the real fault at each reference end when the F1 fault occurs in Table 1 are expressed by the following formula:

[0126]

[0127] Each element in the fault branch decision matrix can be calculated, so that the fault branch decision matrix M can be obtained:

[0128]

[0129] From the above content, it can be seen that when F1 fails, the element values ​​corresponding to the A and B columns in the judgment matrix are both equal to 1, which meets the condition that the reference node a corresponding to the A reference terminal and the B reference terminal fails, so it can be verified that the fault branch judgment is correct.

[0130] Table 2: The arrival time of the first wave detected at each reference end during F1 fault and the energy spectrum density of the initial traveling wave amplitude of the fault

[0131]

[0132]

[0133] Furthermore, the fault distance is accurately calculated. Table 2 shows the arrival time of the first wave head detected by each reference end during the F1 fault and the amplitude energy spectrum density of the initial fault traveling wave. According to the amplitude energy spectrum density of the first wave head of the initial fault traveling wave of each reference end in Table 2, the reference ends with the top three amplitude energy spectrum densities are selected, and the traveling wave time information is used to accurately calculate the fault distance. Figure 6 is a schematic diagram of the calibration of the first wave arrival time of the reference end when an F1 fault occurs according to an embodiment of the present application, such as Figure 6 As shown, the arrival time of the first wave can be calibrated. Figure 7 is a schematic diagram of a fault point accurate positioning based on a reference end according to an embodiment of the present application, based on Figure 7 The topological information of the lines between the three reference ends is shown in Figure 1. According to the distance calculation results, the distance from the fault point F1 to the branch node a is 11m.

[0134] Optionally, when the upper reference node b fails, Figure 5 The energy spectral density of the initial traveling wave head amplitude of the benchmark fault extracted from the corresponding reference end when each reference node simulates a fault in , and the energy spectral density of the initial traveling wave head amplitude of the real fault at each reference end when the F2 fault occurs in Table 1 are used to calculate each element in the fault branch decision matrix, and the fault branch decision matrix M can be obtained:

[0135]

[0136] According to the above formula, when F2 fails, C in the branch decision matrix b and F b The element values ​​corresponding to the columns are all equal to 1, which satisfies the condition that the reference node b corresponding to the C reference terminal and the F reference terminal fails, so it can be verified that the fault branch judgment is correct.

[0137] Optionally, when the main feeder bc branch fails, combined with Figure 5 The energy spectrum density of the initial traveling wave head amplitude of the reference fault extracted from the corresponding reference end when each reference node simulates the fault in Table 1, and the energy spectrum density of the initial traveling wave head amplitude of the real fault at each reference end when the F4 fault occurs in Table 1, can be used to calculate each element in the fault branch decision matrix, and the fault branch decision matrix M can be obtained as follows:

[0138]

[0139] From the above formula, we can know that when F4 fails, all elements in the branch decision matrix are greater than 1, which meets the condition of the fault between the aˉd nodes of the main feeder. Therefore, the auxiliary fault branch decision matrix K can be constructed:

[0140]

[0141] From the above formula, we can see that the element values ​​corresponding to columns a and b are less than 1, and the element values ​​corresponding to columns c and d are greater than 1. The condition for a fault between node b and node c is met, so it can be verified that the fault branch judgment is correct.

[0142] Optionally, when a be branch with multiple branch nodes fails, Figure 5 The energy spectrum density of the initial wave head amplitude of the reference fault extracted from the reference end when each reference node simulates faults, and the energy spectrum density of the initial wave head amplitude of the real fault corresponding to the reference end when the F5 fault occurs in Table 1, can be used to calculate each element in the fault branch decision matrix, and the fault branch decision matrix M can be obtained as follows:

[0143]

[0144] From the above formula, we can know that when F5 fails, C in the branch decision matrix b and F b The element values ​​corresponding to the column are all less than 1, and the column F where the subordinate reference node e is located e and C e The elements are all greater than 1, which satisfies the condition that a fault occurs between the lower-level reference node e and the upper-level reference node b. Therefore, it can be verified that the fault branch judgment is correct.

[0145] Furthermore, the adaptability of the method under different fault conditions can be analyzed. The adaptability of the proposed fault location method under different fault conditions can be analyzed, and fault simulations can be performed on multi-branch distribution grid lines under different transition resistances, fault initial phase angles and fault types. The specific settings of the fault parameters are as follows: In order to analyze the impact of different fault types, when the transition resistance is 50 ohms (Ω) and the fault initial phase angle is 45 degrees, the A-phase grounding fault (AG), AB-phase fault (AB), AB-phase grounding fault (ABG) and ABC three-phase fault (ABC) are set at F1, F5 and F6 respectively. The fault location method proposed in this embodiment is used for simulation. Table 3 is a simulation result data table of changing the fault type, and the simulation results are shown in Table 3.

[0146] Table 3 Simulation results of changing fault types

[0147]

[0148]

[0149] Optionally, to analyze the influence of different transition resistances, in the case of a phase A grounding fault and a fault initial phase angle of 45°, the transition resistance values ​​can be set to 50Ω, 100Ω, 300Ω and 500Ω at F1, F5 and F6 respectively. The fault location method proposed in this embodiment is used for simulation. Table 4 is a simulation result data table of the transition resistance, and the simulation results are shown in Table 4.

[0150] Table 4 Simulation results of transition resistance

[0151]

[0152] Optionally, simulation results show that the fault location process of the proposed method is intuitive and simple, and the positioning results are accurate. The positioning accuracy is not affected by the fault point position, fault type, transition resistance and fault initial phase angle. The absolute error of the fault distance is within 70 meters. Compared with the existing traveling wave positioning method for multi-branch distribution line faults, this method effectively reduces the influence of line structure, wave head arrival time error and traveling wave velocity on the positioning results, and has a certain fault tolerance.

[0153] Figure 8 is a flow chart of a fault location method according to an embodiment of the present application. Figure 8 As shown, the method may include the following steps:

[0154] Step S801, defining a multi-branch line reference node and a corresponding reference end.

[0155] Step S802: before a real fault occurs, extract the E corresponding to each reference node. ij and E Hj .

[0156] Step S803: after a real fault occurs, extract the E detected by each reference end. if .

[0157] Optionally, the above E if It can be used to characterize the energy spectral density of the initial wave head amplitude.

[0158] Step S804: Based on the monitored E if Construct the fault branch decision matrix.

[0159] Step S805, determine whether the element is equal to 1.

[0160] Optionally, it is determined whether the element (M(I,j)) in the fault branch determination matrix is ​​equal to 1. If yes, step S806 is executed, and if no, step S807 is executed.

[0161] Step S806: determine that the fault is a branch node fault.

[0162] Step S807, determine whether the element is less than 1.

[0163] Optionally, if the element in the fault branch determination matrix is ​​not equal to 1, it may be determined whether the element is equal to 1. If yes, step S808 is executed, and if not, step S809 is executed.

[0164] Step S808: determine that the fault is a single branch fault.

[0165] Step S809, determine whether the element is greater than 1.

[0166] Optionally, if the element is greater than 1, step S810 may be executed, and if not, step S803 may be executed.

[0167] Step S810, constructing a branch decision matrix K.

[0168] Step S811, judging the branch decision matrix K.

[0169] Alternatively, if the branch decision matrix K is, K[H,f] 右 is greater than 1, and K[H,f] 左 If it is less than 1, step S812 can be executed, if not, step S803 can be executed.

[0170] Step S812: There is a fault between the main feeder branch nodes.

[0171] Step S813: the effective fault traveling wave head time detected by each end.

[0172] Optionally, after determining that the fault is a branch node fault or a single branch line fault, or a fault between branch nodes of the main feeder, the head time of an effective fault traveling wave detected at each end may be obtained.

[0173] Step S814, calculating the fault distance.

[0174] Step S815, output the fault location point.

[0175] Optionally, based on the fault distance, the exact location of the fault point can be determined.

[0176] In the embodiment of the present application, the initial wave head amplitude energy spectral density in the distribution network line is first obtained, and based on the initial wave head amplitude energy spectral density, a fault branch determination matrix can be constructed, and based on the fault branch determination matrix, the fault branch is determined. After the fault branch is determined, the fault point in the fault branch can be determined based on the traveling wave time information of the reference end, thereby solving the technical problem of low accuracy of fault location in the distribution network and achieving the technical effect of improving the accuracy of fault location in the distribution network.

[0177] According to an embodiment of the present application, a device for determining a fault point in a distribution network is also provided. It should be noted that the device for determining a fault point in a distribution network of this embodiment can be used to execute the method for determining a fault point in a distribution network of embodiment 1 of the present application.

[0178] Fig. 9 Schematic diagram of a device for determining a fault point in a distribution network according to an embodiment of the present application. Fig. 9 As shown, the device 90 for determining a fault point in a distribution network line may include: an acquisition unit 902 , a construction unit 904 , a first determination unit 906 and a second determination unit 908 .

[0179] The acquisition unit 902 is used to acquire the initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line in response to the presence of a line fault in the distribution network line.

[0180] The construction unit 904 is used to construct a fault branch determination matrix based on the initial wave head amplitude energy spectrum density, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined.

[0181] The first determination unit 906 is configured to determine at least one faulty branch in the distribution network line based on the faulty branch determination matrix, wherein the faulty branch is a branch line in the distribution network line where a fault exists.

[0182] The second determining unit 908 is configured to determine a fault point in the fault branch based on the traveling wave time information corresponding to at least one reference end.

[0183] The device for determining a fault point in a distribution network line of this embodiment obtains, through an acquisition unit, an initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line in response to a line fault in the distribution network line; constructs a fault branch determination matrix based on the initial wave head amplitude energy spectrum density through a construction unit, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; determines, through a first determination unit, at least one fault branch in the distribution network line based on the fault branch determination matrix, wherein the fault branch is a branch line in the distribution network line where a fault exists; determines, through a second determination unit, a fault point in the fault branch based on the traveling wave time information corresponding to at least one reference end, thereby solving the technical problem of low accuracy of fault location in the distribution network and achieving the technical effect of improving the accuracy of fault location in the distribution network.

[0184] The embodiment of the present application may provide a computer terminal, which may be any computer terminal device in a computer terminal group. Optionally, in this embodiment, the computer terminal may also be replaced by a terminal device such as a mobile terminal.

[0185] Optionally, in this embodiment, the computer terminal may be located in at least one network device among a plurality of network devices of the computer network.

[0186] In this embodiment, the above-mentioned computer terminal can execute the program code of the following steps in the method for determining the fault point in the distribution network line: in response to the existence of a line fault in the distribution network line, obtaining the initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line; based on the initial wave head amplitude energy spectrum density, constructing a fault branch determination matrix, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; based on the fault branch determination matrix, determining at least one fault branch in the distribution network line, wherein the fault branch is a branch line with a fault in the distribution network line; based on the traveling wave time information of at least one reference end, determining the fault point in the fault branch.

[0187] Optionally, Fig.10 is a structural block diagram of a computer terminal according to an embodiment of the present application, such as Fig.10 As shown, the computer terminal 1008 may include: one or more (only one is shown in the figure) processors 1002 , a memory 1004 and a transmission device 1006 .

[0188] Among them, the memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the method and device for determining the fault point in the distribution network line in the embodiment of the present application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, the above-mentioned method for determining the fault point in the distribution network line is realized. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory may further include a memory remotely arranged relative to the processor, and these remote memories can be connected to the computer terminal 1008 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0189] The processor can call the information and application stored in the memory through the transmission device to perform the following steps: in response to the existence of a line fault in the distribution network line, obtain the initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line; based on the initial wave head amplitude energy spectrum density, construct a fault branch determination matrix, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; based on the fault branch determination matrix, determine at least one fault branch in the distribution network line, wherein the fault branch is a branch line with a fault in the distribution network line; based on the traveling wave time information of at least one reference end, determine the fault point in the fault branch.

[0190] It can be understood by those skilled in the art that Fig.10 The structure shown is for illustration only, and the computer terminal 1008 may also be a smart phone (such as an Android phone, an iOS phone, etc.), a tablet computer, a PDA, a mobile Internet device (Mobile Internet Devices, abbreviated as MID), a PAD, or other terminal devices. Fig.10 The structure of the computer terminal 1008 is not limited. For example, the computer terminal 1008 may also include Fig.10 More or fewer components (such as network interfaces, display devices, etc.) shown in, or having Fig.10 Different configurations are shown.

[0191] A person of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the hardware related to the terminal device through a program, and the program can be stored in a computer-readable storage medium, and the storage medium may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, etc.

[0192] According to an embodiment of the present application, a computer-readable storage medium is further provided, the computer-readable storage medium including a stored program, wherein the program executes the method for determining a fault point in a distribution network line in the above embodiment.

[0193] Optionally, in this embodiment, the computer-readable storage medium may be located in any one of the computer terminals in a computer terminal group in a computer network, or in any one of the mobile terminals in a mobile terminal group.

[0194] Optionally, in this embodiment, the computer-readable storage medium is configured to store program codes for executing the following steps: in response to the presence of a line fault in the distribution network line, obtaining the initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line; constructing a fault branch determination matrix based on the initial wave head amplitude energy spectrum density, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; determining at least one fault branch in the distribution network line based on the fault branch determination matrix, wherein the fault branch is a branch line in the distribution network line where a fault exists; and determining the fault point in the fault branch based on the traveling wave time information of at least one reference end.

[0195] Optionally, the computer-readable storage medium may also execute program code of the following steps: using the target value, judging the elements in the fault branch determination matrix to obtain the fault branch.

[0196] Optionally, the computer-readable storage medium may also execute program code for the following steps: in response to an element corresponding to the reference end being a target value in a fault branch determination matrix, determining a reference node corresponding to the reference end as a fault branch node; and determining a branch line between the reference end and the fault branch node as a fault branch.

[0197] Optionally, the computer-readable storage medium may also execute program codes of the following steps: obtaining the standard wave head amplitude energy spectrum density corresponding to the reference end under the simulated fault state; constructing a fault branch judgment matrix based on the standard wave head amplitude energy spectrum density and the initial wave head amplitude energy spectrum density.

[0198] Optionally, the computer-readable storage medium may also execute program code for the following steps: before a line fault occurs in the distribution network line, determine at least one reference end in the distribution network line; determine a reference node corresponding to the reference end; perform a simulated fault test on the reference node to obtain a standard wave head amplitude energy spectrum density.

[0199] Optionally, the computer-readable storage medium may also execute program code of the following steps: based on the traveling wave time information, obtaining the distance between the fault point to be determined and the fault branch node in the fault branch; based on the distance, determining the fault point in the fault branch.

[0200] In this embodiment, the initial wave head amplitude energy spectral density in the distribution network line is first obtained, and based on the initial wave head amplitude energy spectral density, a fault branch determination matrix can be constructed, and based on the fault branch determination matrix, the fault branch is determined. After the fault branch is determined, the fault point in the fault branch can be determined based on the traveling wave time information of the reference end, thereby solving the technical problem of low accuracy of fault location in the distribution network and achieving the technical effect of improving the accuracy of fault location in the distribution network.

[0201] According to an embodiment of the present application, a processor is also provided, which is used to run a program, wherein when the program is run by the processor, the method for determining a fault point in a distribution network line in the above embodiment is executed.

[0202] Optionally, in this embodiment, the computer terminal may be located in at least one network device among a plurality of network devices of the computer network.

[0203] In this embodiment, the above-mentioned computer terminal can execute the program code of the following steps in the method for determining the fault point in the distribution network line: in response to the existence of a line fault in the distribution network line, obtaining the initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line; based on the initial wave head amplitude energy spectrum density, constructing a fault branch determination matrix, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; based on the fault branch determination matrix, determining at least one fault branch in the distribution network line, wherein the fault branch is a branch line with a fault in the distribution network line; based on the traveling wave time information of at least one reference end, determining the fault point in the fault branch.

[0204] Among them, the memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the method and device for determining the fault point in the distribution network line in the embodiment of the present application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, realizing the above-mentioned method for determining the fault point in the distribution network line. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the computer terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0205] The processor can call the information and application stored in the memory through the transmission device to perform the following steps: in response to the existence of a line fault in the distribution network line, obtain the initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line; based on the initial wave head amplitude energy spectrum density, construct a fault branch determination matrix, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; based on the fault branch determination matrix, determine at least one fault branch in the distribution network line, wherein the fault branch is a branch line with a fault in the distribution network line; based on the traveling wave time information of at least one reference end, determine the fault point in the fault branch.

[0206] According to an embodiment of the present application, a computer program product is also provided, which includes computer instructions, wherein when the computer instructions are executed by a processor, the method for determining a fault point in a distribution network line in the above embodiment is implemented.

[0207] An embodiment of the present application may provide an electronic device, which may include a memory and a processor.

[0208] Fig.11 It is a block diagram of an electronic device for determining a fault point in a distribution network line according to an embodiment of the present application. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present application described and / or required herein.

[0209] like Fig.11 As shown, the device 1100 includes a computing unit 1101, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 1102 or a computer program loaded from a storage unit 1108 to a random access memory (RAM) 1103. In the RAM 1103, various programs and data required for the operation of the device 1100 can also be stored. The computing unit 1101, the ROM 1102, and the RAM 1103 are connected to each other via a bus 1104. An input / output (I / O) interface 1105 is also connected to the bus 1104.

[0210] A number of components in the device 1100 are connected to the I / O interface 1105, including: an input unit 1106, such as a keyboard, a mouse, etc.; an output unit 1107, such as various types of displays, speakers, etc.; a storage unit 1108, such as a disk, an optical disk, etc.; and a communication unit 1109, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 1109 allows the device 1100 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0211] The computing unit 1101 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 1101 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The computing unit 1101 performs the various methods and processes described above, such as a verification method for data. For example, in some embodiments, the verification method for data may be implemented as a computer software program, which is tangibly included in a machine-readable medium, such as a storage unit 1108. In some embodiments, part or all of the computer program may be loaded and / or installed on the device 1100 via the ROM 1102 and / or the communication unit 1109. When the computer program is loaded into the RAM 1103 and executed by the computing unit 1101, one or more steps of the verification method for data described above may be executed. Alternatively, in other embodiments, the computing unit 1101 may be configured to execute the data verification method in any other appropriate manner (for example, by means of firmware).

[0212] According to an embodiment of the present application, a method for determining a fault point in a distribution network line is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0213] Various embodiments of the systems and techniques described above herein may be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on a chip (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include: being implemented in one or more computer programs that may be executed and / or interpreted on a programmable system including at least one programmable processor that may be a dedicated or general purpose programmable processor that may receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0214] The program code for implementing the method of the present application can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0215] In the context of the present application, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0216] To provide interaction with a user, the systems and techniques described herein may be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or an LCD (liquid crystal display, monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a path ball) through which the user can provide input to the computer. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0217] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a Local Area Network (LAN), a Wide Area Network (WAN), and the Internet.

[0218] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

[0219] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0220] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0221] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0222] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0223] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0224] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or all or part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk, etc., which can store program code.

[0225] The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for determining a fault point in a distribution network, characterized in that: include: In response to a line fault in a distribution network line, obtaining an initial wave head amplitude energy spectral density of at least one reference end in the distribution network line; Based on the initial wave head amplitude energy spectral density, a fault branch determination matrix is ​​constructed, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; Based on the fault branch determination matrix, determining at least one fault branch in the distribution network line, wherein the fault branch is a branch line in the distribution network line where a fault exists; The fault point in the fault branch is determined based on the traveling wave time information corresponding to at least one of the reference ends.

2. The method according to claim 1, characterized in that The determining at least one fault branch in the distribution network line based on the fault branch determination matrix comprises: The elements in the fault branch determination matrix are judged by using the target value to obtain the fault branch.

3. The method according to claim 2, characterized in that The using the target value to judge the elements in the fault branch determination matrix to obtain the fault branch includes: In response to the element corresponding to the reference end being the target value in the fault branch determination matrix, determining the reference node corresponding to the reference end as a fault branch node; A branch line between the reference end and the fault branch node is determined as the fault branch.

4. The method according to claim 1, characterized in that: The constructing of a fault branch determination matrix based on the initial wave head amplitude energy spectrum density includes: Obtaining the standard wave head amplitude energy spectral density corresponding to the reference end under the simulated fault state; The fault branch determination matrix is ​​constructed based on the standard wave head amplitude energy spectral density and the initial wave head amplitude energy spectral density.

5. The method according to claim 4, characterized in that The obtaining of the standard wave head amplitude energy spectrum density corresponding to the reference end under the simulated fault state includes: Before the line fault occurs in the distribution network line, determining at least one reference end in the distribution network line; Determine a reference node corresponding to the reference end; A simulated fault test is performed on the reference node to obtain the standard wave head amplitude energy spectral density.

6. The method according to any one of claims 1 to 5, characterized in that The determining the fault point in the fault branch based on the traveling wave time information corresponding to at least one of the reference ends includes: Based on the traveling wave time information, obtaining a distance between the fault point to be determined and a fault branch node in the fault branch; Based on the distance, the fault point is determined in the fault branch.

7. A device for determining a fault point in a distribution network, characterized in that: include: An acquisition unit, configured to acquire, in response to a line fault in a distribution network line, an initial wave head amplitude energy spectrum density of at least one reference end in the distribution network line; A construction unit, configured to construct a fault branch determination matrix based on the initial wave head amplitude energy spectral density, wherein the fault branch determination matrix is ​​used to represent the attenuation degree of the fault traveling wave signal in the distribution network line when it reaches the reference end from the fault point to be determined; A first determination unit is used to determine at least one fault branch in the distribution network line based on the fault branch determination matrix, wherein the fault branch is a branch line in the distribution network line where a fault exists; The second determining unit is used to determine the fault point in the fault branch based on the traveling wave time information corresponding to at least one of the reference ends.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 6.

9. A processor, characterized in that: The processor is used to run a program, wherein the program executes the method according to any one of claims 1 to 6 when run by the processor.

10. A computer program product, characterized in that The method comprises computer instructions, which implement the method according to any one of claims 1 to 6 when executed by a processor.

Images