Fault section based distribution network self-healing method, device and medium

Abstract

The application discloses a power distribution network self-healing method and device based on a fault interval, and a medium. The method comprises the following steps: traversing a directed graph from a root node to a load side along a power supply direction layer by layer, adding a first node associated with a first fault signal to a first set until the boundary is reached, and meanwhile, adding a first node in the first set that meets a preset condition as a fault node of a second set; starting from the fault node, backtracking to a trip device along a reverse adjacency list step by step, retaining only a fault node closest to the load side on each power supply path of a power distribution network system to form a target set; determining a fault interval based on the target set, and isolating the fault and restoring power supply in a non-fault interval based on the fault interval. The embodiment of the application can isolate the fault interval, and accurately restore power supply in the non-fault interval.

Description

Technical Field

[0001] This application relates to, but is not limited to, the field of distribution network self-healing technology, and in particular to a distribution network self-healing method, device and medium based on fault intervals. Background Technology

[0002] With the deepening of the national strategy for new urbanization and high-quality development of power distribution networks, the scale of power distribution networks in urban and suburban areas continues to expand, and the network structure is becoming increasingly complex. A large number of 10kV distribution lines adopt a mixed laying method of cables and overhead lines, with numerous branches and frequent connections, forming a complex topology with multiple segments and connections.

[0003] Current mainstream distribution automation systems generally adopt a centralized feeder automation mode: On the distribution network topology, based on the overcurrent protection signals reported by the terminals (equipped with FTUs / DTUs) of each node, each branch traces back from the terminal node to find the first node to report an overcurrent signal, and the section between that node and the terminal node is determined as the fault section. However, when dealing with the complex network architecture of the distribution network, the terminals only report the "present / absent" status of the overcurrent without directional information. When a fault occurs in a branch, the fault current crosses the upstream common node, causing it to report. When tracing back from the end of other healthy branches to the same common node, the healthy branch may also be mistakenly identified as a fault section. Based on this, performing self-healing operations according to the fault section may incorrectly isolate healthy lines, or, during power restoration, connect the actually faulty section to the opposite system via a tie switch, triggering the protection trip of the opposite line and causing a power outage in the non-faulty area. Summary of the Invention

[0004] This application provides a method, device, and medium for self-healing of a distribution network based on a fault section, which can isolate the fault section and accurately restore power supply to the non-fault section.

[0005] In a first aspect, embodiments of this application provide a self-healing method for distribution networks based on fault intervals, characterized in that it is applied to a distribution network system, and the method includes: Using the tripping device as the root node, and combining the power flow direction and the topology of the distribution network system, a directed graph and a reverse adjacency list corresponding to the directed graph are constructed, wherein the directed graph includes multiple first nodes; For the directed graph, starting from the root node, traverse layer by layer along the power supply direction towards the load side, add the first node associated with the first fault signal to the first set, until the boundary is reached, and at the same time, take the first node in the first set that meets the preset conditions as the fault node of the second set. Starting from the fault node, the reverse adjacency list is traced back level by level to the tripping device. Only the fault node closest to the load side is retained in each power supply path of the power distribution network system to form a target set. Based on the target set, fault ranges are determined, and fault isolation and power restoration to non-fault ranges are performed based on the fault ranges.

[0006] Secondly, an electronic device provided according to an embodiment of this application includes: At least one processor; At least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the self-healing method for distribution networks based on fault intervals according to any one of the first aspects is implemented.

[0007] Thirdly, according to the embodiments of the application, a computer-readable storage medium is provided, storing computer-executable instructions, which are used to execute the distribution network self-healing method based on fault intervals as described in any of the first aspects.

[0008] In summary, the above embodiments of this application, based on the self-healing method of a distribution network in fault sections, include: using a tripping device as the root node, and combining the power flow direction and the topology of the distribution network system, constructing a directed graph and a corresponding reverse adjacency list, wherein the directed graph includes multiple first nodes; for the directed graph, traversing layer by layer along the power supply direction from the root node to the load side, adding the first nodes associated with the first fault signal to a first set, until the boundary is reached, and simultaneously using the first nodes in the first set that meet preset conditions as fault nodes in the second set; starting from the fault node, tracing back step by step along the reverse adjacency list to the tripping device, retaining only the fault node closest to the load side in each power supply path of the distribution network system, forming a target set; determining the fault section based on the target set, and performing fault isolation and power restoration in non-fault sections based on the fault section. In this embodiment, the directed graph is traversed layer by layer from the root node along the power supply direction towards the load side. The first node associated with the first fault signal is added to the first set until the boundary is reached, so that the first node reporting the first fault signal from each power supply line is added to the first set. Then, the first nodes in the first set are filtered according to preset conditions to obtain the fault nodes in the second set. Next, starting from the fault node, the reverse adjacency list is traced back level by level to the tripped device. If there are other fault nodes on the traversal path, the upstream ones are determined to be false fault signals caused by through current and are removed. Only the fault node closest to the load side is retained in each power supply path of the distribution network system to form a target set. Each fault node in the target set has been confirmed as the real fault indicator node at the downstream end of its power supply path through reverse purification. Based on this, the reliability of the fault interval and non-fault interval determined by the target set is improved. Finally, fault isolation is performed based on the fault interval, while power supply is accurately restored to the non-fault interval. Attached Figure Description

[0009] Figure 1 This is a flowchart of the steps of a distribution network self-healing method based on fault intervals provided in one embodiment of this application; Figure 2 This application provides a flowchart of self-healing based on fault intervals in one embodiment; Figure 3 This application provides a fault zone determination circuit diagram in one embodiment; Figure 4 This application provides a fault zone transfer circuit diagram as one embodiment; Figure 5 This is a hardware schematic diagram of an electronic device provided in one embodiment of this application. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0011] It is understandable that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, or the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0012] With the deepening of the national strategy for new urbanization and high-quality development of power distribution networks, the scale of power distribution networks in urban and suburban areas continues to expand, and the network structure is becoming increasingly complex. A large number of 10kV distribution lines adopt a mixed laying method of cables and overhead lines, with numerous branches and frequent connections, forming a complex topology with multiple segments and connections.

[0013] Current mainstream distribution automation systems generally adopt a centralized feeder automation mode: On the distribution network topology, based on the overcurrent protection signals reported by the terminals (equipped with FTUs / DTUs) of each node, each branch traces back from the terminal node to find the first node to report an overcurrent signal, and the section between that node and the terminal node is determined as the fault section. However, when dealing with the complex network architecture of the distribution network, the terminals only report the "present / absent" status of the overcurrent without directional information. When a fault occurs in a branch, the fault current crosses the upstream common node, causing it to report. When tracing back from the end of other healthy branches to the same common node, the healthy branch may also be mistakenly identified as a fault section. Based on this, performing self-healing operations according to the fault section may incorrectly isolate healthy lines, or, during power restoration, connect the actually faulty section to the opposite system via a tie switch, triggering the protection trip of the opposite line and causing a power outage in the non-faulty area.

[0014] This application provides a method, device, and medium for self-healing of a distribution network based on a fault section, which can isolate the fault section and accurately restore power supply to the non-fault section.

[0015] In this embodiment, the directed graph is traversed layer by layer from the root node along the power supply direction towards the load side. The first node associated with the first fault signal is added to the first set until the boundary is reached, so that the first node reporting the first fault signal from each power supply line is added to the first set. Then, the first nodes in the first set are filtered according to preset conditions to obtain the fault nodes in the second set. Next, starting from the fault node, the reverse adjacency list is traced back level by level to the tripped device. If there are other fault nodes on the traversal path, the upstream ones are determined to be false fault signals caused by through current and are removed. Only the fault node closest to the load side is retained in each power supply path of the distribution network system to form a target set. Each fault node in the target set has been confirmed as the real fault indicator node at the downstream end of its power supply path through reverse purification. Based on this, the reliability of the fault interval and non-fault interval determined by the target set is improved. Finally, fault isolation is performed based on the fault interval, while power supply is accurately restored to the non-fault interval.

[0016] This application provides a self-healing method for distribution networks based on fault intervals, applied to distribution network systems, with reference to... Figure 1 and Figure 2 As shown, the method includes, but is not limited to, the following steps: Step S100: Using the tripping device as the root node, and combining the power flow direction and the topology of the distribution network system, construct a directed graph and the corresponding reverse adjacency list of the directed graph. The directed graph includes multiple first nodes.

[0017] Understandably, the main station of the distribution network system receives the tripping remote signal from SCADA, identifies the equipment that has tripped due to short circuit or overcurrent protection actions, such as circuit breakers or sectionalizing switches, and records it as Strip, which serves as the unique root node for fault location. Then, based on the topology indicated by the GIS / CIM power grid model, and combined with the real-time opening and closing status of all switches (including tie switches) indicated by the power flow direction, a directed topology graph G = (V, E) is constructed with Strip as the source point and the edge direction strictly following the normal power flow direction. At the same time, a reverse adjacency list is generated for subsequent path backtracking and pruning.

[0018] Specifically, when a main circuit breaker or sectionalizing switch trips, and its associated distribution terminal (such as FTU / DTU) reports a continuous overcurrent or short circuit protection signal, the signal purification module verifies the validity of the signal (i.e., eliminates interference such as transient disturbances and communication false alarms). Using the tripped device Strip as the root node, a single radial directed tree is constructed as a directed graph based on the current switch status and power connectivity. Only the valid power supply path from the power supply side through Strip to the downstream load is retained. This tree structure is used to reflect the connectivity status and power supply logic before and after the fault.

[0019] Step S110: For the directed graph, start from the root node and traverse layer by layer along the power supply direction to the load side. Add the first node associated with the first fault signal to the first set until the boundary is reached. At the same time, the first node in the first set that meets the preset conditions is taken as the fault node of the second set.

[0020] For example, in this embodiment of the application, the tripping device traverses the load side in a one-way manner using breadth-first or depth-first search, without relying on the reporting of the end terminal, until the boundary is reached, ensuring that the traversal covers all reachable branches; during the traversal process, the first node associated with the first fault signal is added to the first set to obtain all nodes suspected of being faulty, and the first node in the first set that meets the preset conditions is used as the fault node in the second set.

[0021] Specifically, taking breadth-first search (BFS) as an example, starting from the direct downstream child node of the strip, the process traverses layer by layer towards the load side along the power supply direction. When a node v is visited and it stores a time-aligned valid fault protection signal (usually retained for 180 seconds), the reverse purification operation to form the target set is immediately triggered. The traversal terminates the current branch when it encounters a boundary, such as a breaker switch, tie switch, or physical end of the line, thus obtaining the first set.

[0022] In some embodiments, simultaneously selecting a first node in the first set that meets preset conditions as a fault node in the second set includes: calculating the time difference between the timestamp associated with the first node and the time difference between the tripping device; selecting a first node whose time difference is within a preset interval and whose fault type is the same as the fault type of the tripping device as a fault node.

[0023] Specifically, during the topology traversal, the fault signals reported by each device are verified in real time. If the time difference between the reporting time of a device signal and the time difference between the tripping event and the time difference is ≤ 180 seconds (i.e., within the effective time window of the fault signal), and its fault type (such as overcurrent stage I, zero-sequence current) is consistent with the protection action logic of the tripping device, it is determined to be a valid fault signal, and the node is designated as the fault node.

[0024] It is understood that the embodiments of this application utilize the timing constraint that the time difference falls within a preset interval to effectively eliminate delayed signals caused by communication delays and clock asynchrony, as well as pre-interference caused by equipment malfunctions, thereby improving the fault tolerance rate in complex communication environments. On this basis, the logical constraint of fault type consistency is superimposed to confirm the causal relationship between candidate nodes and tripped devices from an electrical and physical perspective, cutting off interference from topologically adjacent but electrically unrelated nodes. In this way, not only are false fault signals eliminated, but redundant nodes that sense faults upstream but are not the faulty entity are also excluded, providing a solid basis for subsequent accurate isolation and rapid recovery.

[0025] Step S120: Starting from the fault node, backtrack along the reverse adjacency list to the tripped device, and retain only the fault node closest to the load side in each power supply path of the distribution network system to form a target set.

[0026] For example, reverse cleanup includes: tracing back from the fault node v along the reverse adjacency list to the Strip. If there is another first node w (and w≠v) that has been added to the valid fault set on the tracing path, it is determined to be a false fault signal caused by the through current and is removed. Then, the fault node is added to the target set (ValisFaultSet) to ensure that each power supply path retains only one fault node closest to the load side.

[0027] It is understandable that when a branch fails, the fault current crosses the upstream common node, causing it to report an overcurrent signal. In existing technologies, other healthy branches, after tracing back to the same common node from their respective ends, may also misclassify that healthy branch as a faulty section. This application's embodiment uses a reverse adjacency list to trace back level by level, retaining only the faulty node with the largest topology depth and closest to the load side on the same power supply path. Upstream common nodes that trigger signals due to cross-current are identified as false signals and removed, thus cutting off the path for the cross-current signal to spread to healthy branches. Each power supply path retains at most one genuine faulty node.

[0028] In some embodiments, in each power supply path of the distribution network system, only the fault node closest to the load side is retained to form a target set. This includes: obtaining the depth value corresponding to all fault nodes in the second set; taking out each corresponding fault node in descending order of depth value; skipping if the fault node has been removed; otherwise, starting from the fault node, backtracking along the reverse adjacency list to obtain the parent node level by level towards the tripping device, removing the nodes encountered in the backtracking process in the second set, until the tripping device is reached, thus forming the target set.

[0029] In some embodiments, obtaining the depth values ​​corresponding to all fault nodes in the second set includes: calculating the depth value of the first node when the directed graph is traversed layer by layer along the power supply direction from the root node to the load side in a breadth-first manner; and determining the depth value corresponding to the fault node based on the depth value corresponding to the first node.

[0030] For example, using the second set of faulty nodes obtained after filtering according to preset conditions as input, a breadth-first traversal is performed along the forward adjacency list starting from the tripping device. The topological depth of each node in the entire directed tree is marked (the depth of the tripping device is 0, its direct downstream depth is 1, and so on). After extracting the depth value corresponding to the faulty node, the list of faulty nodes is sorted in descending order of depth to ensure that the faulty node closest to the load side on each power supply path is processed first. Then, an empty target set and a removed set are initialized, and each faulty node is taken out in descending order. If the node has been removed, it is skipped; otherwise, starting from the node, the parent node is obtained level by level along the reverse adjacency list towards the tripping device. In the radial topology, each non-root node has one and only one parent node. When a parent node that also belongs to the set of fault nodes is encountered on the backtracking path, it is determined to be an upstream pseudo-fault signal caused by the through current and added to the removed set. This process continues until the backtracking reaches the tripped device. After the backtracking is completed, the current fault node is added to the target set as the unique representative of its power supply path. After traversing all fault nodes, the target set is globally unique. At most one fault node closest to the load side is retained on each power supply path with actual faults, while all common nodes of upstream through current-triggered signals fall into the removed set, thus cutting off the path for the through signal to spread to healthy branches.

[0031] Specifically, in the topology where the tripping device branches into a faulty branch S2 and a healthy branch S3 via a common node S1, the faulty nodes {S1, S2} are processed first after being sorted by depth in descending order. The backtracking path S2→S1→tripping device determines S1 as an upstream false signal and removes it. When processing S1 subsequently, it is skipped because it has already been removed from the set. The final target set only retains {S2}. There are no faulty nodes on the S3 branch from beginning to end, which fundamentally eliminates the possibility of the healthy branch being misjudged as a faulty section.

[0032] It is understandable that when multiple faulty nodes have the same depth value, these faulty nodes with the same depth value are processed in any order. Since these faulty nodes with the same depth value are located on different power supply paths and are not in each other's backtracking paths, the processing order does not affect the final result of the target set. Step S130: Determine the fault range based on the target set, and perform fault isolation and power restoration to the non-fault range based on the fault range.

[0033] For example, in this application embodiment, for each device in the target set, combined with downstream effective devices, the smallest fault segment containing the device is defined, and this segment is the finally confirmed fault interval. The master station system uses the accurate fault interval to automatically generate an isolation and transfer operation sequence (i.e., operation ticket). Under the premise of meeting the safety verification conditions, the fault interval boundary switch is opened to clear the fault, and the optimal interconnection switch is closed to restore power supply to the non-faulty area, so that power supply can be accurately restored.

[0034] In some embodiments, determining the fault interval based on the target set includes: for each candidate node in the target set, extending it step by step along the directed graph toward the load side; adding all the first nodes and segments along the way to the fault interval until the fault boundary is reached, forming multiple fault intervals.

[0035] Understandably, referring to Figure 3 As shown, after dynamic signal purification is completed and the target set is obtained (i.e., only one fault node closest to the load side is retained on each power supply path), the minimum fault interval synthesis stage begins. Since each node in the target set has undergone reverse backtracking purification, there are no other fault nodes with a greater topology depth on the same power supply path, and all upstream fault nodes have been eliminated. Therefore, each node in the target set satisfies the two conditions of local maximum topology depth and not being covered by upstream effective fault signals, and is directly used as a candidate starting point (i.e., a candidate node). Subsequently, starting from this candidate starting point, the graph extends downstream level by level along the forward adjacency list of the directed graph, incorporating all nodes and segments along the way into the current fault interval, until the termination condition of encountering any of the following fault boundaries is met, such as reaching the physical end of the line (i.e., a leaf node with zero out-degree), reaching... The non-faulty sectionalizing switches or the normally open tie switches (i.e., isolation points) are confirmed; ordinary nodes on the extended path (such as T-junctions without terminal coverage and intermediate connection points) are also included in the fault interval to ensure the spatial continuity of the fault interval. In this way, each candidate starting point and the segment covered by its downstream extension constitute a minimum continuous fault interval. Fault intervals generated by different candidate starting points do not overlap because they are located on different power supply paths in the topology. When there are multiple candidate starting points, multiple minimum continuous fault intervals are generated, corresponding to the fault range of the main line segment, a single branch line, or multiple independent branches, respectively, to achieve parallel identification and precise isolation of multi-point faults.

[0036] In some embodiments, fault isolation based on the fault section and power restoration of the non-fault section include: fault isolation based on the boundary switch corresponding to the fault section; designating the non-fault section located between the tripped device and the upstream boundary of the fault section as the first section, and the non-fault section between the downstream boundary of the fault section and the end of the load side as the second section, wherein the first section is associated with a first restoration strategy, the second section is associated with a second restoration strategy, and the first restoration strategy and the second restoration strategy are different; restoring power supply to the first section by closing the circuit breaker according to the first restoration strategy, and restoring power supply to the second section by transferring power supply according to the second restoration strategy.

[0037] In some embodiments, restoring power supply to the second interval according to the second restoration strategy includes: Identify the target transfer line corresponding to the second section; close the target interconnection switch on the target transfer line to restore power supply to the second section.

[0038] In some embodiments, determining the target transfer line corresponding to the second interval includes: starting from the downstream boundary of the second interval, traversing along the directed graph towards the load side, searching for the undetermined tie switch of the opposite side feeder; after verifying the feasibility of the undetermined tie switch, selecting the undetermined tie switch with the largest standby capacity as the target undetermined tie switch, thereby determining the target transfer line.

[0039] For example, after the fault section is isolated, the power restoration is performed in parallel on the first section and the second section. The first section is the healthy section between the upstream of the tripping device and the upstream boundary switch of the fault section. For the first section: firstly, a safety check is performed before closing, confirming that the remote signaling status of all boundary switches in the fault section is in the open position, the tripping device has no blocking signal, and there are no new fault alarms between the downstream and the boundary switch. After the check is passed, the master station sends a remote closing command to the terminal of the tripping device to make it close again. Since the upstream boundary switch is already in the open position, closing the tripping device only restores the intermediate healthy load, and the fault section will not be reconnected. The second interval is the healthy branch downstream of the fault interval that is out of power due to the interruption of the power supply path. For the second interval: starting from each downstream boundary switch, traverse downstream along the forward adjacency list to identify the branch to be transferred, and then search for reachable normally open tie switches from the end of the branch to form a candidate list. The feasibility of transferring power to each candidate tie switch is evaluated one by one. Specifically, the opposite feeder is fault-free and in normal power supply state, the current load rate on the opposite side plus the estimated value of the load to be transferred does not exceed 80% of the rated capacity, the voltage on the opposite side of the tie switch is not lower than 90% of the rated value, and the tie switch itself is not blocked and can be remotely controlled. All of these conditions must be met to be included in the feasible list and sorted according to the priority of the largest standby capacity on the opposite side, the fewest important users, and the best communication quality. The optimal tie switch is selected as the target transfer path. Finally, the closing command of the tripped equipment in the first section and the closing command of the optimal tie switch in the second section are issued in the same control cycle and executed simultaneously without waiting at each level. After execution, the closing of each switch is confirmed by remote signaling. If the closing of the first section fails, an alarm is triggered and manual intervention is initiated. If the closing of the tie switch in the second section fails, the system automatically switches to the second-ranked alternative tie switch in the sequence for retry.

[0040] For example, after power is restored, the load rate of the feeder on the opposite side is continuously monitored. If it exceeds 90%, an early warning is triggered; if it exceeds 100%, an emergency load reduction or switching to a backup tie switch is initiated. Simultaneously, the power direction of the tie switch is monitored to ensure that it is a positive feed current to the opposite side's transfer area, and the boundary switch of the fault section is kept in the open position until the on-site fault is repaired and the network is restored. The entire restoration process, from isolation confirmation to concurrent closing control, is completed within seconds. Users in non-faulty areas can quickly regain power after a short power outage without having to endure the multiple impacts of traditional step-by-step power restoration.

[0041] For example, refer to Figure 4As shown in Table 1, after confirming the minimum fault range, the system performs a highly reliable and minimally impactful self-healing operation: using concurrent remote control mode, the upstream and downstream automated boundary switches SW4, SW5, and SW8 of the fault range (between SW4 and SW5, and between SW8 and SW9) are simultaneously tripped, strictly limiting the power outage range to PB2 and PB3 to avoid affecting non-faulty areas; using concurrent remote control mode, the power supply side switch SW1 (restoring PB1) and the load side optimal tie switch (based on the principle of prioritizing the maximum standby capacity, selecting the path with the larger available capacity among SW7 and SW11) are closed in one go, and PB3 is restored via the corresponding line, realizing rapid power restoration for all non-faulty users without the need for step-by-step trial power restoration.

[0042] Table 1

[0043] It is understood that, based on the real-time topology and tie switch status (SW7 and SW11 are both in normally open standby state), and taking into account key constraints such as the maximum available standby capacity, the distribution of important users on the line, and the real-time load rate, the system automatically selects the safest and most reasonable power transfer path, supporting multi-power source and multi-tie point collaborative power transfer.

[0044] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described self-healing method for power distribution networks based on fault intervals. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0045] Please see Figure 5 , Figure 5 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes: The processor 501 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application. The memory 502 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 502 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 502 and is called and executed by the processor 501 to implement the fault-section-based distribution network self-healing method of the embodiments of this application. The input / output interface 503 is used to implement information input and output; The communication interface 504 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.). Bus 505 transmits information between various components of the device (e.g., processor 501, memory 502, input / output interface 503, and communication interface 504); The processor 501, memory 502, input / output interface 503, and communication interface 504 are connected to each other within the device via bus 505.

[0046] In some embodiments, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described self-healing method for distribution networks based on fault intervals.

[0047] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0048] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0049] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0050] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0051] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0052] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0053] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0054] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0055] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0056] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0057] If the integrated unit is implemented as 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 this application, in essence, 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. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A self-healing method for distribution networks based on fault sections, characterized in that, Applied to a power distribution network system, the method includes: Using the tripping device as the root node, and combining the power flow direction and the topology of the distribution network system, a directed graph and a reverse adjacency list corresponding to the directed graph are constructed, wherein the directed graph includes multiple first nodes; For the directed graph, starting from the root node, traverse layer by layer along the power supply direction towards the load side, add the first node associated with the first fault signal to the first set, until the boundary is reached, and at the same time, take the first node in the first set that meets the preset conditions as the fault node of the second set. Starting from the fault node, the reverse adjacency list is traced back level by level to the tripping device. Only the fault node closest to the load side is retained in each power supply path of the power distribution network system to form a target set. Based on the target set, fault ranges are determined, and fault isolation and power restoration to non-fault ranges are performed based on the fault ranges.

2. The self-healing method for distribution networks based on fault intervals according to claim 1, characterized in that, The step of simultaneously including the first node in the first set that meets the preset conditions as the fault node in the second set includes: Calculate the time difference between the timestamp associated with the first node and the tripping device; The first node whose time difference is within a preset interval and whose fault type is the same as that of the tripping device is selected as the fault node.

3. The self-healing method for distribution networks based on fault intervals according to claim 1, characterized in that, The target set, which retains only the fault node closest to the load side in each power supply path of the distribution network system, includes: Obtain the depth values ​​corresponding to all the fault nodes in the second set; Each corresponding fault node is retrieved sequentially in descending order of the depth value. If the fault node has been removed, it is skipped. Otherwise, starting from the fault node, the parent node is retrieved level by level along the reverse adjacency list and backtracked towards the tripping device. Nodes encountered during the backtracking process in the second set are removed until the tripping device is reached, thus forming the target set.

4. The self-healing method for distribution networks based on fault intervals according to claim 3, characterized in that, The step of obtaining the depth values ​​corresponding to all the fault nodes in the second set includes: When the directed graph is traversed layer by layer from the root node along the power supply direction to the load side in a breadth-first manner, the depth value of the first node is calculated. The depth value corresponding to the faulty node is determined based on the depth value corresponding to the first node.

5. The self-healing method for distribution networks based on fault intervals according to claim 1, characterized in that, The step of determining the fault range based on the target set includes: For each candidate node in the target set, extend the directed graph step by step towards the load side; All the first nodes and segments passed through are added to the fault interval until the fault boundary is reached, forming multiple fault intervals.

6. The self-healing method for distribution networks based on fault intervals according to claim 1, characterized in that, The process of isolating faults in the faulty area and restoring power to non-faulty areas includes: Fault isolation is performed based on the boundary switches corresponding to the fault interval; The non-faulty section located between the tripping device and the upstream boundary of the faulty section is designated as the first section, and the non-faulty section between the downstream boundary of the faulty section and the end of the load side is designated as the second section. The first section is associated with a first recovery strategy, and the second section is associated with a second recovery strategy. The first recovery strategy and the second recovery strategy are different. Power supply to the first section is restored by closing the circuit breaker according to the first restoration strategy, and power supply to the second section is restored by transferring the circuit breaker according to the second restoration strategy.

7. The self-healing method for distribution networks based on fault intervals according to claim 6, characterized in that, The step of restoring power supply to the second interval according to the second restoration strategy includes: Determine the target transfer line corresponding to the second interval; Close the target interconnection switch on the target transfer line to restore power supply to the second section.

8. The distribution network self-healing method based on fault intervals according to claim 7, characterized in that, The determination of the target transfer line corresponding to the second interval includes: Starting from the downstream boundary of the second interval, traverse along the directed graph toward the load side to search for the undetermined tie switch of the opposite feeder. After verifying the feasibility of the pending tie switch, the pending tie switch with the largest standby capacity is selected as the target pending tie switch, thereby determining the target transfer line.

9. An electronic device, characterized in that, include: At least one processor; At least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the self-healing method for distribution networks based on fault intervals as described in any one of claims 1 to 8 is implemented.

10. A computer-readable storage medium storing computer-executable instructions, characterized in that, The computer-executable instructions are used to execute the distribution network self-healing method based on fault intervals as described in any one of claims 1 to 8.

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