Self-healing system and method adaptive to network topology change of power distribution network

Abstract

The invention discloses a self-healing system and method adaptive to network topology change of a power distribution network, and belongs to the field of self-healing of the power distribution network. The invention discloses a self-healing system and method adaptive to network topology change of a power distribution network. The self-healing system comprises an intelligent terminal, a self-healing host and an interconnection switch. According to the method, the problems of topology complexity and fault recovery delay caused by existing high-proportion distributed power supply access are solved, an intelligent terminal is deployed on a distribution network station, topology search information, switch state information and electric quantity information are transmitted through a differential channel, a network connection relation is dynamically constructed in combination with an improved BFS algorithm, and the fault recovery efficiency is improved. The method comprises the following steps: realizing real-time automatic identification of topological change, judging a switch type in a fault isolation stage, realizing fault isolation and power supply recovery in combination with a virtual trip-entity trip cooperation mechanism, generating a load transfer path by adopting a bidirectional Dijkstra algorithm after successful fault isolation, locking and self-healing when a path load is greater than a set threshold, and stopping self-healing when a power condition is met. And executing multi-interconnection switch self-healing sequence operation.

Description

Technical Field

[0001] This invention relates to the field of distribution network self-healing technology, specifically to a self-healing system and method for adaptive distribution network topology changes. Background Technology

[0002] With the increasing integration of distributed power sources into distribution networks, network topologies are becoming more complex. When system failures occur, fault isolation and power restoration times are getting longer, while power users have increasingly higher requirements for power supply reliability. Therefore, conventional distribution automation can no longer meet the requirements of modern society for power supply reliability.

[0003] Traditional distribution network self-healing aims to improve the reliability and stability of the power grid by rapidly detecting, isolating faults, and restoring power supply. However, these technologies still have the following drawbacks and limitations in practical applications:

[0004] 1. Traditional self-healing technologies often employ relatively simple recovery strategies, making it difficult to cope with complex and ever-changing network topologies. They cannot quickly and accurately identify and adapt to topology changes, nor can they adapt to complex scenarios, resulting in a high risk of misjudgment.

[0005] 2. Fault handling relies on centralized decision-making at the main station, involves multiple communication layers, and has a long fault isolation and power restoration time. The overall restoration time exceeds 500ms, which cannot meet the high requirements of modern society for power supply reliability.

[0006] 3. Path calculation relies on fixed rules, ignores real-time power balance and equipment capacity constraints, and the load transfer path is not optimized enough, which may lead to unreasonable power allocation.

[0007] 4. The switching coordination of multiple self-healing switches is poor. There is a lack of dynamic priority strategy when switching multiple self-healing switches, which can easily cause conflicts and affect the overall self-healing effect.

[0008] Therefore, it does not meet the existing requirements. In response, we propose a self-healing system and method for adaptive distribution network topology changes. Summary of the Invention

[0009] The purpose of this invention is to provide a self-healing system and method for adaptive distribution network topology changes. By deploying intelligent terminals at distribution stations, topology search information, switch status information, and electrical quantity information are transmitted through differential channels. Combined with an improved BFS algorithm, network connection relationships are dynamically constructed to achieve real-time identification of topology changes. During the fault isolation phase, switch types are identified, and a virtual tripping-physical tripping coordination mechanism is used to achieve fault isolation and power restoration. After successful fault isolation, a bidirectional Dijkstra algorithm is used to generate load transfer paths. When the path load exceeds a set threshold, self-healing is blocked. When the power condition is met, a multi-tie switch self-healing sequence operation is executed, solving the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a self-healing system for adaptive distribution network topology changes, comprising:

[0011] The intelligent terminal is configured to periodically transmit communication messages to each other through the differential protection communication channel of the interconnected lines. The messages include voltage, current, switch type, switch status, node type, topology search identifier and self-healing discrimination status.

[0012] The self-healing host is configured such that when the switch is set to self-healing switch, the smart terminal corresponding to the switch automatically becomes the self-healing host.

[0013] The handshake switch is configured to perform a multi-handshake switch self-healing sequence operation after fault isolation;

[0014] Both the smart terminal and the self-healing host have a built-in differential protection module and both support 5G and fiber optic dual-mode communication.

[0015] Furthermore, the smart terminal and the self-healing host communicate via a differential protection communication channel.

[0016] Furthermore, the operation quality of the differential protection communication channel is monitored in real time, and anomaly alarms are triggered when abnormal operation occurs, including:

[0017] Real-time monitoring of the operating parameters of the differential protection communication channel;

[0018] The bit error rate and differential delay asymmetry corresponding to each unit time of operation of the differential protection communication channel are retrieved from the operating parameters.

[0019] The bit error rate and differential delay asymmetry corresponding to each unit time are normalized to obtain the normalized bit error rate and differential delay asymmetry corresponding to each unit time.

[0020] The average normalized bit error rate and the average normalized differential delay asymmetry are obtained by using the normalized bit error rate and differential delay asymmetry corresponding to each unit of time.

[0021] The normalized average bit error rate and the normalized average differential delay asymmetry are compared.

[0022] When the difference between the normalized average bit error rate and the normalized average differential delay asymmetry exceeds a preset difference threshold, the operating quality of the differential protection communication channel is evaluated using the normalized average bit error rate and the normalized average differential delay asymmetry, and a channel anomaly alarm is triggered when an anomaly occurs.

[0023] Furthermore, the operational quality of the differential protection communication channel is evaluated using the normalized average bit error rate and the normalized average differential delay asymmetry, and channel anomaly alarms are triggered in case of anomalies, including:

[0024] Retrieve the signal phase change amplitude parameter from the aforementioned operating parameters;

[0025] Retrieve preset phase parameter reference values ​​from the database;

[0026] The phase ratio parameter is obtained by comparing the signal phase change amplitude parameter with a preset phase parameter reference value.

[0027] Retrieve the normalized average bit error rate and the normalized average differential delay asymmetry.

[0028] The operation evaluation coefficients corresponding to the differential protection communication channel are obtained by combining the normalized average bit error rate and the normalized average differential delay asymmetry with the phase ratio parameter.

[0029] The operational evaluation coefficients are compared with preset coefficient thresholds;

[0030] If the operation evaluation coefficient is lower than the preset coefficient threshold, the channel operation is determined to be abnormal and an abnormal alarm is triggered.

[0031] Furthermore, the communication switch includes:

[0032] Switch failure, no charging, communication interruption, and device malfunction are all considered to fail to meet the self-healing conditions.

[0033] If the optimal self-healing switch does not meet the conditions, a backup self-healing switch is searched in descending order of priority.

[0034] A self-healing method for adaptive distribution network topology changes, used to implement a self-healing system for adaptive distribution network topology changes, includes the following steps:

[0035] According to the smart terminals configured on the distribution network, each smart terminal in the area periodically transmits communication messages to each other through the differential protection communication channel of the interconnected lines.

[0036] Based on the topology search identifier, a dynamic node association matrix is ​​constructed by parsing messages using an improved BFS algorithm to identify changes in the distribution network topology in real time. If a node's message is not received for several consecutive periods, it is determined that the node has left the network, while newly added nodes are automatically added to the association matrix through broadcast topology node registration.

[0037] When a fault occurs, the intelligent terminal identifies the type of switch in the faulty section. If it is a load switch, it sends a virtual trip command to the adjacent circuit breaker. After the upstream circuit breaker performs the actual disconnection, it feeds back a trip permission signal. After receiving the trip permission signal, the load switch performs a fault-free trip. After the load switch trips, the adjacent circuit breaker closes the circuit.

[0038] After the fault is successfully isolated, the optimal transfer path is calculated using the bidirectional Dijkstra algorithm based on the load status before the fault, and the maximum load of the transfer path is calculated. When the maximum load is determined to be greater than the set threshold, self-healing is blocked. When the maximum load is less than the set threshold, the multi-connection switch self-healing sequence operation is executed.

[0039] If the optimal self-healing tie switch does not meet the conditions, search for a backup self-healing tie switch in descending order of priority.

[0040] If the high-priority self-healing switch does not meet the self-healing conditions, the self-healing function will be handed over to the low-priority self-healing interconnection switch according to the network topology.

[0041] Furthermore, the topology status of the distribution network system is identified in real time to form the network topology.

[0042] Furthermore, after the load switch trips, the upstream circuit breaker will automatically close the circuit after detecting that the load switch has successfully tripped.

[0043] Furthermore, after fault isolation, the optimal transfer path is calculated using the bidirectional Dijkstra algorithm based on the network topology fed back by the correlation matrix.

[0044] Furthermore, the improved BFS algorithm supports high-capacity node networks to complete topology refresh within milliseconds, and reuses the differential protection channel to transmit topology search identifiers, switch states, and node types without adding additional communication settings.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] This invention deploys intelligent terminals at distribution stations and uses differential channels to transmit topology search information, switch status information, and electrical quantity information. Combined with an improved BFS algorithm, it dynamically constructs network connection relationships, enabling real-time identification of topology changes. This allows the distribution network to quickly sense and accurately update network connection relationships when the network structure changes, providing a reliable foundation for subsequent control operations.

[0047] During the fault isolation phase, this invention can accurately identify the switch type and, combined with a virtual tripping-physical tripping coordination mechanism, quickly achieve fault isolation and power restoration. This coordination mechanism can effectively avoid problems such as fault expansion or power restoration delay caused by untimely or inaccurate switch actions, thereby improving the reliability and stability of the power supply network. Through precise fault isolation, the fault area can be limited to the smallest possible range, minimizing the number of users affected by power outages and the duration of outages, thus enhancing the user's electricity experience.

[0048] This invention uses a bidirectional Dijkstra algorithm to generate the optimal transfer path after successful fault isolation, which can improve transfer efficiency and reduce power loss during the transfer process. When the path load is greater than the set threshold, self-healing is blocked to avoid system instability or even fault expansion caused by overload. Only when the power condition is met will the multi-tie switch self-healing sequence operation be executed, ensuring the safety and stability of the distribution network during the self-healing process. Attached Figure Description

[0049] Figure 1 This is a system architecture diagram of the present invention;

[0050] Figure 2 This is a flowchart of the automatic topology search process of the present invention;

[0051] Figure 3 This is the logic diagram of the virtual-physical tripping coordination and self-healing of the present invention. Detailed Implementation

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0053] Please see Figures 1-3 , this embodiment provides the following technical solutions:

[0054] A self-healing system for adaptive distribution network topology changes includes:

[0055] The intelligent terminal is configured to periodically transmit communication messages to each other through the differential protection communication channel of the interconnected lines. The messages include voltage, current, switch type, switch status, node type, topology search identifier and self-healing discrimination status.

[0056] The self-healing host is configured such that when the switch is set to self-healing switch, the smart terminal corresponding to the switch automatically becomes the self-healing host.

[0057] The handshake switch is configured to perform a multi-handshake switch self-healing sequence operation after fault isolation;

[0058] Both the smart terminal and the self-healing host have a built-in differential protection module and both support 5G and fiber optic dual-mode communication.

[0059] The technical effects of the above are as follows: The intelligent terminal periodically transmits communication messages through the differential protection communication channel. The self-healing host and the tie switch work together to quickly locate the fault point when a fault occurs, and achieve fault isolation through the self-healing sequence operation of the tie switch, while restoring power to the non-faulty area. Compared with traditional methods, its self-healing action time can be shortened from minutes to milliseconds, greatly reducing power outage time and scope. Both the intelligent terminal and the self-healing host have built-in differential protection modules, which can effectively improve the protection reliability of the distribution network after a large number of new energy sources are connected. Differential protection can quickly and accurately detect and act on faults, reducing the impact of faults on the power grid. Both the intelligent terminal and the self-healing host support 5G and fiber optic dual-mode communication. Compared with single fiber optic communication, 5G communication has a lower deployment cost, especially in areas with good 5G network coverage such as cities and suburbs. Through dual-mode communication, the scope and cost of fiber optic laying can be reduced while meeting system performance requirements.

[0060] The smart terminal and the self-healing host communicate through a differential protection communication channel. Each smart terminal communicates with the high-priority self-healing host, and the high-priority self-healing host communicates with the low-priority self-healing host.

[0061] The technical effects of the above are as follows: The differential protection communication channel enables the intelligent terminal to transmit data such as current to the self-healing host in real time and accurately. The self-healing host performs differential protection calculations based on this data, thereby improving the sensitivity and selectivity of relay protection, effectively avoiding problems caused by misjudgment of fault points, and improving power supply reliability. The intelligent terminal quickly transmits fault information to the self-healing host through the differential protection communication channel. The host, combining the differential protection principle and self-healing algorithm, can quickly locate the fault section and control the corresponding equipment to isolate the fault, minimizing the scope of the fault's impact and reducing power outage time. Furthermore, the differential protection communication channel provides the self-healing host with timely and accurate equipment status and power grid operation information, enabling it to make rapid decisions and execute self-healing operations. For example, after a fault occurs in the distribution network, the self-healing system can complete fault isolation and power restoration to non-faulty areas within milliseconds, greatly shortening the self-healing time compared to traditional fault handling methods.

[0062] Specifically, it monitors the operational quality of the differential protection communication channel in real time and issues an alarm when abnormalities occur, including:

[0063] Real-time monitoring of the operating parameters of the differential protection communication channel;

[0064] The bit error rate and differential delay asymmetry corresponding to each unit time of operation of the differential protection communication channel are retrieved from the operating parameters.

[0065] The bit error rate and differential delay asymmetry corresponding to each unit time are normalized to obtain the normalized bit error rate and differential delay asymmetry corresponding to each unit time.

[0066] The average normalized bit error rate and the average normalized differential delay asymmetry are obtained by using the normalized bit error rate and differential delay asymmetry corresponding to each unit of time.

[0067] The normalized average bit error rate and the normalized average differential delay asymmetry are compared.

[0068] When the difference between the normalized average bit error rate and the normalized average differential delay asymmetry exceeds a preset difference threshold, the operating quality of the differential protection communication channel is evaluated using the normalized average bit error rate and the normalized average differential delay asymmetry, and a channel anomaly alarm is triggered when an anomaly occurs.

[0069] The technical effect of the above solution is as follows: First, the bit error rate and differential delay asymmetry corresponding to each unit time are normalized. This is because the original bit error rate and differential delay asymmetry values ​​may be in different orders of magnitude and different ranges. Normalization can map them to the same value range (such as [0,1]), making them comparable and eliminating the impact of differences in units and numerical ranges on subsequent calculations and analyses. Calculating the normalized average bit error rate and average differential delay asymmetry is to reflect the average performance of the channel in terms of data transmission accuracy and time synchronization over a period of time. The average value can smooth out abnormal fluctuations at individual time points and reflect the overall trend of channel operation. The two average values ​​are compared, and the operational quality is evaluated when the difference exceeds a preset threshold. Under normal circumstances, the two should maintain a relatively stable relationship. If the difference is too large, it indicates that the channel has an imbalance in data transmission accuracy and time synchronization. By comparing the magnitude and degree of difference between the two, the quality of channel operation can be judged. If the average bit error rate is significantly higher than the average differential delay asymmetry, it indicates severe interference in the channel and an increase in data transmission errors. Conversely, if the average differential delay asymmetry is too high, there is a time synchronization-related fault, such as clock skew. The evaluation results are used to determine if there is an anomaly and trigger an alarm, thus achieving effective monitoring of the operational quality of the differential protection communication channel.

[0070] By monitoring operational parameters such as the bit error rate and differential delay asymmetry of the differential protection communication channel in real time, subtle changes in the channel's operating status can be captured promptly. Once the difference between the two average values ​​exceeds a preset threshold, an assessment and alarm are triggered, alerting maintenance personnel before a fault occurs. This allows for proactive measures to be taken, reducing the risk of differential protection malfunctions or failures due to channel faults and improving the reliability and stability of the power system. Using the normalized average bit error rate and average differential delay asymmetry to assess channel operating quality transforms complex operating parameters into quantifiable and comparable indicators. This helps maintenance personnel intuitively understand the channel's operating status, distinguish between normal fluctuations and abnormal situations, and provides accurate data for channel maintenance and upgrades, improving maintenance efficiency. Comparing the two dimensions of indicators—bit error rate and differential delay asymmetry—allows for analysis of channel operating problems from different perspectives. When an anomaly occurs, the difference between the two indicators helps determine whether the problem lies in the accuracy of data transmission (bit error rate) or time synchronization (differential delay asymmetry), facilitating more precise fault location and shortening troubleshooting time.

[0071] Specifically, the operational quality of the differential protection communication channel is evaluated using the normalized average bit error rate and the normalized average differential delay asymmetry, and channel anomaly alarms are triggered when anomalies occur, including:

[0072] Retrieve the signal phase change amplitude parameter from the aforementioned operating parameters;

[0073] Retrieve preset phase parameter reference values ​​from the database;

[0074] The phase ratio parameter is obtained by comparing the signal phase change amplitude parameter with a preset phase parameter reference value.

[0075] Retrieve the normalized average bit error rate and the normalized average differential delay asymmetry.

[0076] The operation evaluation coefficients corresponding to the differential protection communication channel are obtained by combining the normalized average bit error rate and the normalized average differential delay asymmetry with the phase ratio parameter.

[0077] The operational evaluation coefficients are obtained using the following formula:

[0078]

[0079] Where U represents the operational evaluation coefficient; W p T represents the average bit error rate after normalization; p The normalized differential delay asymmetry is represented by the average value; S represents the phase ratio parameter; specifically, (1-T) pThis delay difference deviates from the ideal state (no delay difference, i.e., T). p =0) A measure adjustment of degree, 1-S*(1-T) p First, the differential delay asymmetry and phase ratio parameters are comprehensively calculated, and then combined with the bit error rate related terms. The absolute value ensures 1-S×(1-T) p The result of () is used in the calculation in the non-negative case to avoid unreasonable calculation results. The overall formula reflects the system's operating status assessment after comprehensively considering these factors; the value of U will change according to the changes in these parameters. W p This is the normalized average bit error rate. The bit error rate reflects the ratio of the number of erroneously received symbols to the total number of transmitted symbols during data transmission, indicating the transmission errors caused by noise, interference, and other factors. |1-S*(1-T p This factor combines phase and delay. Multiplying the two correlates the bit error rate with the degree to which the signal is affected by the combined effects of phase and delay, measuring the overall impact of these factors on system performance. Taking the absolute value ensures that the result of this calculation is non-negative, conforming to physical meaning and mathematical logic.

[0080] The operational evaluation coefficients are compared with preset coefficient thresholds;

[0081] If the operation evaluation coefficient is lower than the preset coefficient threshold, the channel operation is determined to be abnormal and an abnormal alarm is triggered.

[0082] The technical effects of the above solution are as follows: The signal phase change amplitude parameter is extracted from the operating parameters and compared with a preset phase parameter benchmark value in the database to obtain a phase ratio parameter, reflecting the degree of signal phase change relative to the benchmark. Simultaneously, the normalized average bit error rate and the average differential delay asymmetry are obtained, representing the average levels of data transmission accuracy and time synchronization, respectively. Normalization eliminates differences in the dimensions and numerical ranges of the original parameters, making them comparable. The normalized average bit error rate, the average differential delay asymmetry, and the phase ratio parameter are combined to calculate the operating evaluation coefficient. This is because the bit error rate affects data transmission accuracy, the differential delay asymmetry relates to time synchronization, and the signal phase change affects signal integrity; all three jointly determine the channel's operating quality. Through a specific calculation method (the specific formula is not given, but the principle is a comprehensive consideration), these parameters are integrated into a single value to quantify the channel's operating quality. The operating evaluation coefficient is compared with a preset coefficient threshold. The threshold is set based on the channel's performance indicators during normal operation and the differential protection's requirements for channel quality. If the operation evaluation coefficient is lower than the threshold, it indicates that the channel operation quality has deteriorated to the point of affecting normal operation. The channel operation is judged to be abnormal and an alarm is triggered to remind the operation and maintenance personnel to take measures to maintain the channel.

[0083] The communication channel operation quality is evaluated using a multi-dimensional approach, incorporating parameters such as bit error rate, differential delay asymmetry, and signal phase change amplitude. Compared to single-indicator evaluations, this approach provides a more comprehensive and accurate reflection of the channel's actual operating status, reducing false positives and false negatives and improving evaluation precision. Channel anomalies are identified and alarms are triggered by comparing the operation evaluation coefficient with preset thresholds, providing timely warnings before channel performance degrades to the point of affecting differential protection operation. Maintenance personnel can intervene early to prevent power system failures caused by channel faults, improving power system reliability and stability. The quantified operation evaluation coefficient allows maintenance personnel to intuitively understand channel operation quality and prioritize maintenance. Channels with operation evaluation coefficients close to the threshold require focused attention, enabling the rational allocation of maintenance resources, improved maintenance efficiency, and reduced maintenance costs.

[0084] The handshake switch includes:

[0085] Switch failure to operate, no charging, communication interruption, and device malfunction are all considered to fail to meet the self-healing conditions, among which:

[0086] Switch failure to operate: This refers to a switch that fails to operate normally when required. In this case, the interconnecting switch cannot perform the closing or opening operation according to the self-healing strategy, thus failing to achieve self-healing.

[0087] Not charging: This means that the operating power supply of the switch is not charged, causing the switch to malfunction.

[0088] Communication interruption: refers to the interruption of the communication link between the switch and the control center or other equipment. During the self-healing process, the switch needs to receive control commands or report status information. Communication interruption will prevent the transmission of this information, thereby affecting the implementation of the self-healing strategy.

[0089] Device malfunction: This refers to a fault in the switch itself or its auxiliary devices, which may cause the switch to be unable to correctly determine the fault situation or perform self-healing operations.

[0090] If the optimal self-healing switch does not meet the conditions, a backup self-healing switch is searched in descending order of priority.

[0091] The technical effects of the above are as follows: When the tie switch fails to operate, fails to charge, experiences communication interruption, or malfunctions, it is considered that the self-healing conditions are not met. These abnormalities will cause the tie switch to malfunction and thus fail to achieve the self-healing function. If the optimal self-healing tie switch does not meet the conditions, the system will search for a backup self-healing tie switch in descending order of priority. This means that the system will prioritize the backup switch with higher priority to ensure the reliability and effectiveness of the self-healing operation. In this way, even if the optimal self-healing tie switch fails, the system can still achieve self-healing through the backup switch, thereby improving the self-healing reliability of the entire system. The descending priority search strategy can sort the switches according to their importance and reliability, making the system more reasonable in selecting backup switches, thereby optimizing the self-healing strategy and quickly finding an available backup switch, which can shorten the fault recovery time and reduce the impact of power outages on users.

[0092] Specifically, this embodiment also proposes a self-healing method for adaptive distribution network topology changes, used to implement a self-healing system for adaptive distribution network topology changes, including the following steps:

[0093] According to the smart terminals configured on the distribution network, each smart terminal in the area periodically transmits communication messages to each other through the differential protection communication channel of the interconnected lines.

[0094] Based on the topology search identifier, a dynamic node association matrix is ​​constructed by parsing messages using an improved BFS algorithm to identify changes in the distribution network topology in real time. If a node's message is not received for several consecutive periods, it is determined that the node has left the network, while newly added nodes are automatically added to the association matrix through broadcast topology node registration.

[0095] When a fault occurs, the intelligent terminal identifies the type of switch in the faulty section. If it is a load switch, it sends a virtual trip command to the adjacent circuit breaker. After the upstream circuit breaker performs the actual disconnection, it feeds back a trip permission signal. After receiving the trip permission signal, the load switch performs a fault-free trip. After the load switch trips, the adjacent circuit breaker performs the closing operation. After receiving the information that the load switch has been disconnected, the upstream circuit breaker starts the automatic closing function to achieve a complete fault isolation process.

[0096] When the self-healing switch is not charged or fails to reclose, the backup contact switch is searched, the load is calculated to be lower than the threshold setting, the backup contact switch is closed, and the power supply is restored.

[0097] After the fault is successfully isolated, the optimal transfer path is calculated using the bidirectional Dijkstra algorithm based on the load status before the fault, and the maximum load of the transfer path is calculated. When the maximum load is determined to be greater than the set threshold, self-healing is blocked. When the maximum load is less than the set threshold, the multi-connection switch self-healing sequence operation is executed.

[0098] If the optimal self-healing tie switch does not meet the conditions, search for a backup self-healing tie switch in descending order of priority.

[0099] If the high-priority self-healing switch does not meet the self-healing conditions, the self-healing function will be handed over to the low-priority self-healing interconnection switch according to the network topology.

[0100] The technical effects of the above are as follows: By periodically transmitting communication messages containing various key information through intelligent terminals, combined with the differential protection communication channel, changes in the distribution network topology can be quickly identified, and self-healing control can be completed within milliseconds, significantly improving the self-healing efficiency and response speed of the distribution network. A dynamic node association matrix is ​​constructed using an improved BFS algorithm, enabling real-time identification of distribution network topology changes. New nodes can be automatically added to the association matrix through broadcast "topology node registration," and nodes disconnected from the network can also be identified promptly, thus adapting to complex and ever-changing distribution network topologies. This is particularly suitable for active distribution network scenarios with distributed power sources. In the event of a fault, the intelligent terminal can quickly identify the switch type of the faulty section and achieve fault isolation through a virtual tripping-physical tripping coordination mechanism. After fault isolation, [further details are needed]. The optimal power transfer path is calculated using the bidirectional Dijkstra algorithm, ensuring rapid power restoration through a multi-tethered switch self-healing sequence operation while meeting power requirements. This improves power supply reliability. Multiple tethered switches can work collaboratively; when a high-priority self-healing switch fails to meet self-healing conditions, a backup tethered switch can be searched in descending priority order, avoiding self-healing failure due to a single switch fault and further enhancing system reliability. Based on these operations, real-time monitoring and dynamic updates of the network topology reduce the risk of misjudgment caused by network topology complexity in traditional self-healing technologies. Furthermore, the path optimization engine based on the bidirectional Dijkstra algorithm calculates the optimal power transfer path according to real-time power balance and equipment capacity constraints, avoiding unreasonable power allocation and improving overall system performance.

[0101] The topology status of the distribution network system is identified in real time, and the network topology is formed.

[0102] The technical effects of the above are as follows: By monitoring and dynamically updating the topology of the distribution network in real time, it can quickly respond to any changes in the network, such as the addition, deletion or status change of nodes. Through rapid adaptability, the system can maintain efficient operation in complex and ever-changing distribution network environments, especially in scenarios where frequent access of distributed power sources leads to dynamic changes in the topology. When a fault occurs, it can immediately identify the fault location and its impact on the network topology, thereby quickly formulating fault isolation and power restoration strategies. The real-time topology identification capability significantly shortens fault handling time, reduces the scope and duration of power outages, and improves power supply reliability.

[0103] After the load switch trips, the upstream circuit breaker will automatically close the circuit after detecting that the load switch tripped successfully.

[0104] The technical effects of the above are as follows: Through the virtual tripping-physical tripping coordination mechanism, the load switch trips when there is no fault current, avoiding the fault current surge caused by the direct tripping of the load switch. The upstream circuit breaker only performs the closing operation after confirming that the load switch has successfully tripped, ensuring the thoroughness and safety of fault isolation. When the load switch trips successfully, the upstream circuit breaker immediately starts automatic closing, which can restore power supply to the non-faulty area in a very short time, significantly shortening the power outage time and improving the reliability of power supply.

[0105] After fault isolation, the optimal transfer path is calculated using the bidirectional Dijkstra algorithm based on the network topology fed back by the correlation matrix.

[0106] The technical effects of the above are as follows: The bidirectional Dijkstra algorithm can comprehensively consider factors such as network topology, path length, equipment capacity, and real-time power balance to select the optimal power transfer path. The optimized path selection ensures the rationality of power allocation and avoids overload or insufficient power supply caused by improper path selection. By adopting the bidirectional Dijkstra algorithm, the optimal power transfer path from the power source to the load can be calculated quickly, ensuring rapid power restoration after fault isolation. The path calculation method significantly shortens the power restoration time and improves the self-healing capability of the distribution network. By calculating the optimal power transfer path, the power supply strategy can be quickly adjusted when a fault occurs to ensure continuous power supply to important loads, thereby improving the stability of the distribution network and reducing the risk of power outages caused by faults.

[0107] The improved BFS algorithm supports high-capacity node networks to complete topology refresh in milliseconds, and reuses the differential protection channel to transmit topology search identifiers, switch states, and node types without adding extra communication settings.

[0108] The technical effects of the above are as follows: The improved BFS algorithm can complete the topology refresh of a large-capacity node network within milliseconds, making it suitable for complex and ever-changing distribution network scenarios. The improved BFS algorithm enables the distribution network to better cope with dynamic changes in network topology, supports more node access and more complex network structures, and transmits information such as topology search identifiers, switch status and node types through multiplexing differential protection channels without adding additional communication settings or dedicated communication channels. This design makes full use of existing communication resources, avoids the increased cost and complexity caused by additional communication equipment or lines, and improves the economy and feasibility of the system.

[0109] This invention transmits topology search information via differential channels and dynamically constructs network connections using an improved BFS algorithm. It can identify topology changes in real time and effectively solve the problem of difficult protection configuration in complex scenarios such as multi-terminal lines. During the fault isolation phase, it identifies the switch type and, combined with a virtual tripping-physical tripping coordination mechanism, can quickly and reliably isolate faults, avoiding outages for users in non-faulty areas. After successful fault isolation, it uses a bidirectional Dijkstra algorithm to generate load transfer paths. When the power conditions are met, it executes a multi-tie switch self-healing sequence operation, which can restore power supply in a short time and improve power supply reliability.

[0110] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0111] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A self-healing system for adaptive distribution network topology changes, characterized in that, include: The intelligent terminal is configured to periodically transmit communication messages to each other through the differential protection communication channel of the interconnected lines. The messages include voltage, current, switch type, switch status, node type, topology search identifier and self-healing discrimination status. Among them, the operation quality of the differential protection communication channel is monitored in real time, and an abnormal alarm is triggered when the operation is abnormal; The self-healing host is configured such that when the switch is set to self-healing switch, the smart terminal corresponding to the switch automatically becomes the self-healing host. The handshake switch is configured to perform a multi-handshake switch self-healing sequence operation after fault isolation; Both the smart terminal and the self-healing host have a built-in differential protection module and both support 5G and fiber optic dual-mode communication.

2. The self-healing system for adaptive distribution network topology changes according to claim 1, characterized in that: The smart terminal and the self-healing host communicate through a differential protection communication channel.

3. The self-healing system for adaptive distribution network topology changes according to claim 1, characterized in that: Real-time monitoring of the operational quality of the differential protection communication channel, and issuance of abnormal alarms when abnormal operation occurs, including: Real-time monitoring of the operating parameters of the differential protection communication channel; The bit error rate and differential delay asymmetry corresponding to each unit time of operation of the differential protection communication channel are retrieved from the operating parameters. The bit error rate and differential delay asymmetry corresponding to each unit time are normalized to obtain the normalized bit error rate and differential delay asymmetry corresponding to each unit time. The average normalized bit error rate and the average normalized differential delay asymmetry are obtained by using the normalized bit error rate and differential delay asymmetry corresponding to each unit of time. The normalized average bit error rate and the normalized average differential delay asymmetry are compared. When the difference between the normalized average bit error rate and the normalized average differential delay asymmetry exceeds a preset difference threshold, the operating quality of the differential protection communication channel is evaluated using the normalized average bit error rate and the normalized average differential delay asymmetry, and a channel anomaly alarm is triggered when an anomaly occurs.

4. The self-healing system for adaptive distribution network topology changes according to claim 3, characterized in that: The operational quality of the differential protection communication channel is evaluated using the normalized average bit error rate and the normalized average differential delay asymmetry, and channel anomaly alarms are triggered in case of anomalies, including: Retrieve the signal phase change amplitude parameter from the aforementioned operating parameters; Retrieve preset phase parameter reference values ​​from the database; The phase ratio parameter is obtained by comparing the signal phase change amplitude parameter with a preset phase parameter reference value. Retrieve the normalized average bit error rate and the normalized average differential delay asymmetry. The operation evaluation coefficients corresponding to the differential protection communication channel are obtained by combining the normalized average bit error rate and the normalized average differential delay asymmetry with the phase ratio parameter. The operational evaluation coefficients are compared with preset coefficient thresholds; If the operation evaluation coefficient is lower than the preset coefficient threshold, the channel operation is determined to be abnormal and an abnormal alarm is triggered.

5. The self-healing system for adaptive distribution network topology changes according to claim 1, characterized in that: The communication switch includes: Switch failure, no charging, communication interruption, and device malfunction are all considered to fail to meet the self-healing conditions. If the optimal self-healing switch does not meet the conditions, a backup self-healing switch is searched in descending order of priority.

6. A self-healing method for adaptive distribution network topology changes, used to implement the self-healing system for adaptive distribution network topology changes as described in any one of claims 1-5, characterized in that, Includes the following steps: According to the smart terminals configured on the distribution network, each smart terminal in the area periodically transmits communication messages to each other through the differential protection communication channel of the interconnected lines. Based on the topology search identifier, a dynamic node association matrix is ​​constructed by parsing messages using an improved BFS algorithm to identify changes in the distribution network topology in real time. If a node's message is not received for several consecutive periods, it is determined that the node has left the network, while newly added nodes are automatically added to the association matrix through broadcast topology node registration. When a fault occurs, the intelligent terminal identifies the type of switch in the faulty section. If it is a load switch, it sends a virtual trip command to the adjacent circuit breaker. After the upstream circuit breaker performs the actual disconnection, it feeds back a trip permission signal. After receiving the trip permission signal, the load switch performs a fault-free trip. After the load switch trips, the adjacent circuit breaker closes the circuit. After the fault is successfully isolated, the optimal transfer path is calculated using the bidirectional Dijkstra algorithm based on the load status before the fault, and the maximum load of the transfer path is calculated. When the maximum load is determined to be greater than the set threshold, self-healing is blocked. When the maximum load is less than the set threshold, the multi-connection switch self-healing sequence operation is executed. If the optimal self-healing tie switch does not meet the conditions, search for a backup self-healing tie switch in descending order of priority. If the high-priority self-healing switch does not meet the self-healing conditions, the self-healing function will be handed over to the low-priority self-healing interconnection switch according to the network topology.

7. The self-healing method for adaptive distribution network topology changes according to claim 6, characterized in that: The topology status of the distribution network system is identified in real time, and the network topology is formed.

8. The self-healing method for adaptive distribution network topology changes according to claim 6, characterized in that: After the load switch trips, the upstream circuit breaker will automatically close the circuit after detecting that the load switch tripped successfully.

9. The self-healing method for adaptive distribution network topology changes according to claim 6, characterized in that: After fault isolation, the optimal transfer path is calculated using the bidirectional Dijkstra algorithm based on the network topology fed back by the correlation matrix.

10. The self-healing method for adaptive distribution network topology changes according to claim 6, characterized in that: The improved BFS algorithm supports high-capacity node networks to complete topology refresh in milliseconds, and reuses the differential protection channel to transmit topology search identifiers, switch states, and node types without adding extra communication settings.

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