Distribution line fault self-healing capability evaluation method and system

Abstract

The invention belongs to the technical field of intelligent power distribution networks, and particularly relates to a power distribution line fault self-healing capability evaluation method and system.The method comprises the steps that a power distribution network line is represented with a graph, a switch configured with protection at the upstream of a fault point serves as a starting point, a switch connected with an opposite side line serves as an end point, and switches with equipment defects are removed; on the basis of considering different contributions of a load and a power supply when a fault occurs, an adjacent matrix of a power-losing area after the power distribution network fault is constructed; according to the position of the fault point, correcting the constructed adjacent matrix of the power-losing area after the fault of the power distribution network; and after node contraction is carried out on the corrected adjacent matrix by using a node contraction method, whether the power-losing area has the fault self-healing capability after the fault is judged based on the adjacent matrix after node contraction. According to the method, the adjacency matrix is constructed by fully considering the equipment defects of the distribution line and the switch protection configuration condition, so that the purpose of effectively evaluating the self-healing capability level of the distribution network after the fault is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent distribution network, and in particular relates to a method and system for evaluating the self-healing capability of distribution line faults. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] As one of the important functions of smart distribution networks, fault self-healing is primarily aimed at reducing or even avoiding the impact of faults on the system, ensuring safe and stable operation of the power grid, and ultimately improving the safety, reliability and user satisfaction of the system. With the vigorous promotion of the construction of self-healing smart distribution networks, it is necessary to understand the actual situation of smart distribution network construction and conduct a comprehensive and objective analysis and evaluation of the self-healing capabilities of distribution lines in order to accurately locate the problems and weak links in the self-healing process of smart distribution networks.

[0004] Most of the existing technologies conduct full-area reliability assessment of smart distribution networks from a macro perspective, but do not take into account the defects of distribution automation equipment and the configuration of switch relay protection. On the one hand, they cannot reflect the true self-healing capability of distribution lines, resulting in certain assessment deviations. On the other hand, when a fault with no self-healing path occurs, the self-healing strategy calculation is still required to obtain a solution without self-healing, resulting in a long time for the self-healing solution research and evaluation. Summary of the invention

[0005] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a method and system for evaluating the self-healing capability of a distribution network, which fully considers factors such as equipment defects and distribution network switch protection configuration to construct an adjacency matrix of the power-off area after a distribution network fault, and corrects the constructed adjacency matrix of the power-off area after a fault according to the type of fault node, thereby improving the accuracy of the comprehensive self-healing capability evaluation and realizing a rapid and accurate evaluation of the self-healing capability level of the distribution network after a fault.

[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions: A first aspect of the present invention provides a method for evaluating the self-healing capability of a distribution line fault, comprising: The distribution network line is represented by a graph. According to the fault situation of the distribution network line, the switch configured with protection upstream of the fault point is used as the starting point of the distribution network boundary, and the connecting switch between the distribution network line and the opposite line is used as the end point of the distribution network boundary. The non-automatic switches and automatic switches with equipment defects in this area are removed. On the basis of considering the different contributions of load and power supply when a fault occurs, the adjacency matrix of the power-off area after the distribution line fault is constructed. According to the location of the fault point, the constructed adjacency matrix is ​​corrected, including: if the fault point is a power node, the element corresponding to the fault point in the adjacency matrix is ​​set from 1 to 0; if the fault point is a line section, the elements corresponding to the nodes on both sides of the fault point in the adjacency matrix are set from 1 to 0, and a corrected adjacency matrix is ​​obtained; The node shrinkage method is used to shrink the nodes of the modified adjacency matrix; The connectivity of the power-off area after the fault is judged based on the adjacency matrix after node contraction. If it is connected, it means that the power-off area after the distribution line fault has the fault self-healing capability.

[0007] A second aspect of the present invention provides a distribution line fault self-healing capability evaluation system, comprising: The adjacency matrix construction module is configured to: represent the distribution network line with a graph, and according to the fault situation of the distribution network line, take the switch configured with protection upstream of the fault point as the starting point of the distribution network boundary, and take the connecting switch between the distribution network line and the opposite line as the end point of the distribution network boundary, and remove the non-automatic switches and automatic switches with equipment defects in this area, and construct the adjacency matrix of the power-off area after the distribution line fault on the basis of considering the different contributions of load and power supply when the fault occurs; The adjacency matrix correction module is configured to: correct the constructed adjacency matrix according to the location of the fault point, including: if the fault point is a power node, then the element corresponding to the fault point in the adjacency matrix is ​​set from 1 to 0; if the fault point is a line section, then the elements corresponding to the nodes on both sides of the fault point in the adjacency matrix are set from 1 to 0, so as to obtain a corrected adjacency matrix; The adjacency matrix contraction module is configured to: perform node contraction on the modified adjacency matrix using a node contraction method; The distribution line self-healing capability assessment module is configured to judge the connectivity of the power-off area after the fault based on the adjacency matrix after the node contraction. If it is connected, it means that the power-off area after the distribution line fault has the fault self-healing capability.

[0008] A third aspect of the present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of a method for evaluating the self-healing capability of a distribution line fault as described in the first aspect of the present invention.

[0009] The fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps in a method for evaluating the self-healing capability of a distribution line fault as described in the first aspect of the present invention are implemented.

[0010] One or more of the above technical solutions have the following beneficial effects: (1) The present invention fully considers the actual operation conditions of the distribution network, such as automation equipment defects and protection configuration conditions, and proposes a distribution network self-healing capability evaluation method based on connectivity analysis. The node contraction method is used to quickly determine the connectivity of the network after a fault occurs as a qualitative method to measure the self-healing capability of the line network. This method can not only quickly determine the connectivity of the network, but also avoids the problem that when a fault with no self-healing path occurs, the self-healing strategy calculation is still required to obtain a no self-healing solution, thus saving the time for the self-healing solution research and judgment.

[0011] (2) The present invention fully considers the equipment defects of the distribution line and the switch protection configuration to achieve the purpose of effectively evaluating the self-healing ability of the distribution network after a fault. Compared with considering equipment defects and considering the distribution network switch protection configuration, not considering equipment defects overestimates the success probability of self-healing of the line; while only considering equipment defects without considering the distribution network switch protection configuration underestimates the success probability of self-healing of the line; therefore, when evaluating the self-healing ability of the line, if both equipment defects and distribution network switch protection configuration are not considered at the same time, it will lead to an evaluation deviation of the success probability of self-healing, and fail to reflect the true self-healing ability of the distribution line.

[0012] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0014] Figure 1 This is a flow chart of a method for evaluating the self-healing capability of a power distribution line fault according to the first embodiment.

[0015] Figure 2 This is a flowchart of the node shrinkage method of the first embodiment.

[0016] Figure 3 This is a circuit diagram of the hand-in-hand wiring method of the first embodiment.

[0017] Figure 4 This is a schematic diagram of a 10kV Pumeng line in the first embodiment. DETAILED DESCRIPTION

[0018] Embodiment 1 like Figure 1 As shown, this embodiment discloses a method for evaluating the self-healing capability of a distribution line fault, including: Step 1: Represent the distribution network line with a graph. According to the fault situation of the distribution network line, the switch configured with protection upstream of the fault point is used as the starting point of the distribution network boundary, and the connecting switch between the distribution network line and the opposite line is used as the end point of the distribution network boundary. The non-automatic switches and automatic switches with equipment defects in this area are removed. Considering the different contributions of load and power supply when a fault occurs, the adjacency matrix of the power-off area after the distribution line fault is constructed; Step 2: According to the location of the fault point, the constructed adjacency matrix of the power-off area after the fault is modified; Step 3: Use the node shrinkage method to shrink the elements in the corrected adjacency matrix; Step 4: Determine the connectivity of the fault interval based on the adjacency matrix after node contraction. If it is connected, it means that the power-off area after the distribution line fault has the fault self-healing capability.

[0019] In step 1, the switches in the distribution network line include: in-station outgoing line switches, line section switches, line branch switches, line boundary switches and tie switches, etc.

[0020] Distribution network line faults include: distribution line faults that cause the tripping of station outgoing line switches, line section switches, line branch switches, and line boundary switches. Distribution network line faults are monitored by the distribution automation master station.

[0021] Step 101: according to the fault condition of the distribution network line, the switch configured with protection upstream of the fault point is used as the starting point of the distribution network boundary to be evaluated, and the connecting switch with the opposite line is used as the end point of the distribution network boundary to be evaluated; The present invention takes into account the protection configuration of the in-station outgoing line switch, line segmentation switch, line branch switch and line boundary switch; the switch with protection configuration closest to the upstream of the fault point is the power supply point, and serves as the starting point of the boundary of the distribution network to be evaluated; the connecting switch between the faulty line and the opposite line is also the power supply point, and serves as the end point of the boundary of the distribution network to be evaluated; the constructed adjacency matrix is ​​the adjacency matrix of the power-off area after the distribution network fault; compared with the traditional adjacency matrix of the entire distribution network, the connectivity judgment based on the adjacency matrix of the fault area can quickly judge the connectivity of the network, saving the strategy generation time.

[0022] Step 102: Eliminate the automated switches and non-automated switches with equipment defects, including: non-automated equipment and defective automated equipment (long-term offline, remote control preset failure, primary ring main unit mechanism jam, battery feed and other faults causing remote control failure) are not included in the self-healing evaluation system.

[0023] Step 103: Considering the different contributions of load nodes and power supply nodes when a fault occurs, an adjacency matrix of the power failure area after the distribution line is constructed according to the line and switch information, including: The adjacency matrix is ​​established according to the topological connection relationship between switches. One line in the distribution network corresponds to one adjacency matrix. If the distribution network has N lines, it corresponds to N adjacency matrices.

[0024] For example, suppose there are M defect-free automatic switches on a certain line, and the connection relationship between the switches can be represented by the following adjacency matrix:

[0025] In the formula, Indicates switch i With switch j Directly connected, Indicates switch i With switch j Not directly connected.

[0026] Considering the different contributions of power nodes and load nodes after a fault occurs, i=j , if the node is a power node, then ; If the node is a load node, then .

[0027] Among them, the types of nodes in the power-off area include power supply nodes and load nodes. The switch configured with protection closest to the upstream of the fault point in the distribution network line and the connecting switch between the distribution network line and the opposite line are regarded as power supply side nodes, and other switches are collectively referred to as load side nodes.

[0028] The present invention takes into account that when constructing the adjacency matrix of the distribution network at present, the defects of the distribution network line equipment and the switch protection configuration are usually not taken into account, and the constructed adjacency matrix is ​​the adjacency matrix of the entire area of ​​the distribution network; when the connectivity judgment is performed based on the entire area adjacency matrix, the power outage after the distribution line fault cannot be reflected; therefore, the present invention constructs the adjacency matrix of the power outage area after the distribution line fault according to the equipment defects and the switch protection configuration.

[0029] The present invention further takes into account the different contributions of load and power supply when a fault occurs, and corrects the constructed adjacency matrix of the fault power-off area according to the location of the fault point. The corrected adjacency matrix can reflect the defects of distribution network line equipment and the protection configuration of distribution network switches, and can reflect the true self-healing ability of the distribution line.

[0030] In step 2, according to the location of the fault point, the constructed adjacency matrix of the power-off area after the fault is modified, including: If the fault point is located on the power supply side, the diagonal elements corresponding to the fault point in the adjacency matrix are set from 1 to 0; if the fault point is on the line side, the elements corresponding to the nodes on both sides of the fault point in the adjacency matrix are set from 1 to 0 to disconnect the topology between the nodes on both sides of the fault point and obtain the corrected adjacency matrix.

[0031] For example: When a fault occurs somewhere in the line, if the fault point is located at the power node, then Changes from 1 to 0. If the fault point occurs at the line section, then Changes from 1 to 0, forming a new adjacency matrix A1.

[0032] The line fault section is the area between two defect-free automatic switches. When the line is in a certain line fault section, the successful self-healing count of the line fault is 1, and the failed self-healing count is 0. The total number of successful self-healing counts in the line fault section is the sum of all counts 1.

[0033] In the power system, especially in the power grid after a fault occurs, it cannot accurately reflect whether there is a power outage area in the current network, that is, whether there are isolated nodes. This is because when a fault occurs in the power grid, the contributions of load nodes and power nodes to the network are different; assuming that one or several nodes form an island, if the island only contains load nodes, the system will lose this part of the load; if the island contains power nodes, the load will not be lost without considering the capacity. Therefore, even if the network calculated by the traditional method is not connected, the system can still operate normally in practice. In order to solve the above problems, the present invention corrects the constructed adjacency matrix according to the location of the fault point in the distribution network.

[0034] In step 3, the connectivity of the distribution network is examined using the node contraction analysis method to determine whether the line can be self-healed successfully when the fault point is in a certain fault interval.

[0035] Specifically: the node contraction method is used to quickly determine the connectivity of the network after the failure as an indicator to measure the network's self-healing ability; if the network is connected after the failure, it means that the network has a self-healing path, and the self-healing strategy can be activated to select the best solution for power restoration. If the network is not connected after the failure, self-healing cannot be achieved, and manual dispatching or manual troubleshooting must be adopted to restore power to the power-lost area.

[0036] The node shrinkage method is used to shrink the elements in the modified adjacency matrix, including: "Node contraction" is also called "short circuit contraction", which means short-circuiting two or more terminals to form a new terminal. The rule of node contraction is: when the network has n nodes, if the node k and jContraction to form new nodes , we need to add the first j OK, j Perform Boolean addition on each column until k OK, k Column, then cross out j OK, j After the nodes are shrunk, the diagonal elements are set to zero to obtain a new matrix. If a row or a column in the final matrix is ​​all zero, it means that the network is not connected, otherwise it is a connected network.

[0037] The network after the failure is contracted layer by layer according to the node contraction rule. During the contraction process, the corresponding power supply nodes that have not failed in the adjacency matrix are ensured to be Always "1", the load node corresponds to Always "0".

[0038] like Figure 2 As shown, first construct an n-order adjacency matrix A. Each time it shrinks, the first row ( i =1) and the first column (j=1) to determine whether there is an all-zero row or all-zero column; For example: for the first row in the adjacency matrix A ( i =1) to search, including: Find all elements in the first row of the adjacency matrix A in turn and determine whether the element is zero, that is, determine whether Is it true? If it is true, continue to determine whether the remaining elements in the first row (j=j+1) are 0, until j=n; if all elements in the first row are 0, it is concluded that the graph is disconnected. If not, i The row (column) and the j-th row (column) are “OR” operated, and the result is placed in the j-th row (column); after one “OR” operation, the order of the new adjacency matrix A is n=n-1; If it is a power node, set the diagonal elements to "1", otherwise set them to "0"; determine whether the shrunk adjacency matrix has rows or columns that are all zero; if so, it means that the network of the distribution line is not connected; if not, determine whether the order of the adjacency matrix A is n=2; if so (n=2), it means that the network of the distribution line is connected; if not , then remove the first row and the first column of the original matrix to form a new adjacency matrix, and repeat the above steps until n=2 or there are rows (or columns) with all zeros in the adjacency matrix.

[0039] In step 4, the connectivity of the fault interval is judged based on the adjacency matrix after the node contraction, including: In the process of shrinking nodes layer by layer, it is determined whether there are all-zero rows or all-zero columns in the adjacency matrix after shrinking. If so, the node shrinking stops, indicating that the distribution network after the fault is not connected, that is, it does not have the self-healing ability. If not, the distribution network after the fault is connected, indicating that the power-off area after the distribution line fault has the fault self-healing ability.

[0040] If there are no all-zero rows or columns, the network will continue to shrink until there are only two nodes left. If the adjacency matrix still has no all-zero rows or columns, it means that the original network has a certain self-healing function and the network after the fault has a self-healing path. Otherwise, it means that the original network does not have the self-healing ability for the fault, and the network after the fault does not have a self-healing path, which will cause isolated node loss load.

[0041] Step 5: After determining whether the fault point in the distribution line can self-heal in a certain fault interval, it also includes: enumerating all possible fault intervals in the distribution line, and then determining the number of times the fault point can successfully self-heal in each fault interval through the above-mentioned node contraction method, and finally calculating the full-area self-healing completion rate of the distribution line fault according to the ratio of the sum of the success times of all fault intervals to the sum of all enumerated fault intervals; and evaluating the comprehensive self-healing capability of a distribution line fault according to the full-area self-healing completion rate of the distribution line fault.

[0042] Among them, the self-healing completion rate of the entire area of ​​distribution line faults = (the sum of the number of successful self-healing times of the fault interval / the sum of all enumerated fault intervals) x 100%; where, if a fault interval can be self-healed, the count is 1, otherwise it is 0.

[0043] by Figure 3 The hand-in-hand connection is used as an example to illustrate the method for evaluating the self-healing capability of the distribution network. After a fault occurs at K1, the matrix changes as follows: (1) From formula (1), it can be seen that after the system fails at point K1, no isolated nodes are generated, the original network has a certain self-healing ability, and the network after the failure has a self-healing path. This shows that although the network fails, the non-fault area of ​​the network can automatically restore normal operation through the switch without manual intervention; after actual verification, the conclusion obtained by the evaluation method of the present invention is consistent with the actual operation situation.

[0044] It should be noted that if the distribution network switch has a remote control refusal defect (such as remote control failure of switch 01), it will not be able to participate in fault isolation or non-fault interval recovery; therefore, when using the node contraction analysis method to evaluate whether the line has successfully self-healed, the defective switch should first be deleted from the line network to which it belongs.

[0045] like Figure 4As shown, the 10kV Pumeng line has three automated ring network cabinets K1, K2, and K3, which are connected to the Hanghu line (the connecting switch is H02 of Pumeng line K3). H01 and H02 in Pumeng line K1, H01 and H02 in Pumeng line K2, and H05 in Pumeng line K3 are line segmentation switches; H03 and H04 in Pumeng line K3 are customer boundary switches, and are configured with short-circuit protection settings. H01 in Pumeng line K3 is a branch switch (connecting the rear section of pole #4), and is configured with short-circuit protection settings. The defective equipment is: the K1 operating mechanism is rusted, the K2 and K3 terminals are offline, and the K3 cannot be remotely controlled successfully after power failure, but the switch can be protected and tripped when it fails.

[0046] Through the following four examples, the self-healing capacity of the Pumeng line is evaluated and calculated by the node contraction analysis method, and the calculation results are shown in Tables 1 to 4 respectively.

[0047] Example 1: No consideration of equipment defects or distribution network switch protection configuration; Example 2: Only consider equipment defects and ignore the protection configuration of distribution network switches; Example 3: Ignoring equipment defects and only considering the protection configuration of distribution network switches; Example 4: Considering equipment defects and distribution network switch protection configuration; Table 1 does not consider equipment defects and distribution network switch protection configuration (Example 1)

[0048] Table 2 only considers equipment defects and does not consider the protection configuration of distribution network switches (Example 2)

[0049] Table 3 does not consider equipment defects and only considers the protection configuration of distribution network switches (Example 3)

[0050] Table 4 Considering equipment defects and distribution network switch protection configuration (Example 4)

[0051] Based on the above examples 1 to 4, the self-healing completion rates of the line faults in the whole area are calculated as shown in Table 5; Table 5 Considering equipment defects and distribution network switch protection configuration

[0052] As shown in Table 5, compared with Example 4 (33.3%) which fully considers the actual operation of the line, Examples 1 and 3 (100%) overestimate the self-healing capacity of the line, while Example 2 (0%) underestimates the self-healing capacity of the line.

[0053] In order to improve the fault self-healing capability of the line, there are seven solutions for equipment transformation: Option 1: Reconstruction of Pumeng Line K1; Option 2: Reconstruction of Pumeng Line K2; Option 3: Reconstruction of Pumeng Line K3; Option 4: Reconstruction of K1 and K2 of Pumeng Line; Plan 5: Reconstruction of K1 and K3 of Pumeng Line; Plan 6: Reconstruction of K2 and K3 of Pumeng Line; Plan 7: Reconstruct K1, K2 and K3 of Pumeng Line.

[0054] After the above seven schemes are transformed, the self-healing completion rate indicators of the entire area of ​​the transformed line faults are calculated as shown in Table 6.

[0055] Table 6 The self-healing completion rate of line faults in the whole area under different transformation schemes

[0056] As can be seen from Table 6, considering factors such as project funding and renovation time, it is more reasonable to prioritize the renovation of K3 of the Pumeng Line (Scheme 3). The self-healing completion rate of the line fault in the entire area has increased from 33.3% before the renovation to 100%, and the line self-healing capacity has been greatly improved.

[0057] Embodiment 2 This embodiment discloses a distribution line fault self-healing capability evaluation system, including: The adjacency matrix construction module is configured to: represent the distribution network line with a graph, and according to the fault situation of the distribution network line, take the switch configured with protection upstream of the fault point as the starting point of the distribution network boundary, and take the connecting switch between the distribution network line and the opposite line as the end point of the distribution network boundary, and remove the non-automatic switches and automatic switches with equipment defects in this area, and construct the adjacency matrix of the power-off area after the distribution line fault on the basis of considering the different contributions of load and power supply when the fault occurs; The adjacency matrix correction module is configured to: correct the constructed adjacency matrix according to the location of the fault point, including: if the fault point is a power node, then the element corresponding to the fault point in the adjacency matrix is ​​set from 1 to 0; if the fault point is a line section, then the elements corresponding to the nodes on both sides of the fault point in the adjacency matrix are set from 1 to 0, so as to obtain a corrected adjacency matrix; The adjacency matrix contraction module is configured to: perform node contraction on the modified adjacency matrix using a node contraction method; The distribution line self-healing capability assessment module is configured to judge the connectivity of the power-off area after the fault based on the adjacency matrix after the node contraction. If it is connected, it means that the power-off area after the distribution line fault has the fault self-healing capability.

[0058] Embodiment 3 The purpose of this embodiment is to provide a computer-readable storage medium.

[0059] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in a method for evaluating the self-healing capability of a distribution line fault as described in Example 1 of the present disclosure.

[0060] Embodiment 4 The purpose of this embodiment is to provide an electronic device.

[0061] An electronic device includes a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps in a method for evaluating the self-healing capability of a distribution line fault as described in Example 1 of the present disclosure are implemented.

[0062] The steps involved in the apparatuses of the above embodiments 2, 3 and 4 correspond to the method embodiment 1, and the specific implementation methods can refer to the relevant description part of embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood to include any medium that can store, encode or carry an instruction set for execution by a processor and enable the processor to execute any method in the present invention.

[0063] Those skilled in the art should understand that the modules or steps of the present invention described above can be implemented by a general-purpose computer device, or alternatively, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0064] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A method for evaluating the self-healing capability of a distribution line fault, characterized in that: include: The distribution network line is represented by a graph. According to the fault situation of the distribution network line, the switch configured with protection upstream of the fault point is used as the starting point of the distribution network boundary, and the connecting switch between the distribution network line and the opposite line is used as the end point of the distribution network boundary. The non-automatic switches and automatic switches with equipment defects in this area are removed. On the basis of considering the different contributions of load and power supply when a fault occurs, the adjacency matrix of the power-off area after the distribution line fault is constructed. According to the location of the fault point, the constructed adjacency matrix is ​​corrected, including: if the fault point is a power node, the element corresponding to the fault point in the adjacency matrix is ​​set from 1 to 0; if the fault point is a line section, the elements corresponding to the nodes on both sides of the fault point in the adjacency matrix are set from 1 to 0, and a corrected adjacency matrix is ​​obtained; The node shrinkage method is used to shrink the nodes of the modified adjacency matrix; The connectivity of the power-off area after the fault is judged based on the adjacency matrix after node contraction. If it is connected, it means that the power-off area after the distribution line fault has the fault self-healing capability.

2. A method for evaluating the self-healing capability of a power distribution line fault according to claim 1, characterized in that: The automatic switches configured with protection in the distribution network line and the connecting switches between the distribution network line and the opposite line are regarded as power supply nodes, and other switches in the distribution network line are regarded as load nodes.

3. A method for evaluating the self-healing capability of a power distribution line fault as claimed in claim 2, characterized in that: The switches in the distribution network line include: in-station outgoing line switches, line section switches, line branch switches, line boundary switches and contact switches.

4. A method for evaluating the self-healing capability of a power distribution line fault according to claim 1, characterized in that: The node shrinkage method is used to shrink the elements in the modified adjacency matrix, including: The adjacency matrix has a total of n nodes. If nodes k and j are contracted to form a new node , it is necessary to perform Boolean addition of the j-th row and j-th column in the adjacency matrix to the k-th row and k-th column respectively, and then cross out the j-th row and j-th column. At this time, the node shrinkage is completed.

5. A method for evaluating the self-healing capability of a power distribution line fault as claimed in claim 4, characterized in that: When there are rows or columns with all zeros in the adjacency matrix or the order of the adjacency matrix is ​​n=2, it means that the adjacency matrix has been shrunk.

6. A method for evaluating the self-healing capability of a power distribution line fault according to claim 1, characterized in that: The determining of the connectivity of the power-off area after the fault based on the adjacency matrix after the node contraction includes: It is determined whether there are all-zero rows or all-zero columns in the adjacency matrix after the node contraction. If so, it means that the power-off area is not connected after the distribution line fault; if not, it means that the power-off area is connected after the distribution line fault.

7. A method for evaluating the self-healing capability of a power distribution line fault according to claim 1, characterized in that: After determining whether the fault point in the distribution line is in a certain fault range and can be self-healed, it also includes: For all possible fault intervals in the distribution line, the number of times that self-healing can be successfully performed is determined by the node contraction method; the self-healing completion rate of the entire distribution line fault area is calculated based on the ratio of the sum of the successful times of all fault intervals to the sum of all enumerated fault intervals; and the comprehensive self-healing capability of the distribution line fault is evaluated based on the self-healing completion rate of the distribution line fault area.

8. A distribution line fault self-healing capability evaluation system, characterized in that: include: The adjacency matrix construction module is configured to: represent the distribution network line with a graph, and according to the fault situation of the distribution network line, take the switch configured with protection upstream of the fault point as the starting point of the distribution network boundary, and take the connecting switch between the distribution network line and the opposite line as the end point of the distribution network boundary, and remove the non-automatic switches and automatic switches with equipment defects in this area, and construct the adjacency matrix of the power-off area after the distribution line fault on the basis of considering the different contributions of load and power supply when the fault occurs; The adjacency matrix correction module is configured to: correct the constructed adjacency matrix according to the location of the fault point, including: if the fault point is a power node, then the element corresponding to the fault point in the adjacency matrix is ​​set from 1 to 0; if the fault point is a line section, then the elements corresponding to the nodes on both sides of the fault point in the adjacency matrix are set from 1 to 0, so as to obtain a corrected adjacency matrix; The adjacency matrix contraction module is configured to: perform node contraction on the modified adjacency matrix using a node contraction method; The distribution line self-healing capability assessment module is configured to judge the connectivity of the power-off area after the fault based on the adjacency matrix after the node contraction. If it is connected, it means that the power-off area after the distribution line fault has the fault self-healing capability.

9. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by a processor, the steps in the method for evaluating the self-healing capability of a distribution line fault as described in any one of claims 1 to 7 are implemented.

10. An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps in the method for evaluating the self-healing capability of a distribution line fault as described in any one of claims 1 to 7 are implemented.

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