A distribution network fault self-healing method and system based on stacking topology

Abstract

The present invention provides a distribution network fault self-healing method and system based on a stacking topology, the method comprising: obtaining the current of each node in the distribution network through each intelligent terminal, and judging the abnormality of the current of each node according to a preset current threshold; stacking and connecting the intelligent terminals, generating a stacking topology of the distribution network according to the network topology information of each intelligent terminal, and controlling information interaction between the intelligent terminals through the stacking topology of the distribution network; according to the current of each node and the network topology information, performing information interaction between the nodes through the intelligent terminals to obtain fault location; based on the fault location, controlling the switches of the nodes in the fault area through the intelligent terminals to isolate the fault and obtain fault isolation information; according to the fault isolation information, controlling the status of each switch through the intelligent terminal to restore the power supply of the distribution network, thereby realizing fast and accurate fault location, fault isolation and power restoration in the active distribution network.

Description

Technical Field

[0001] The present invention relates to the field of distributed power distribution networks, and in particular to a distribution network fault self-healing method and system based on a stacking topology. Background Art

[0002] With the rapid development of smart distribution networks, related technologies such as distributed generation (DG) have been added to distribution networks, changing the original unidirectional current flow direction of distribution networks to bidirectional or multi-terminal flow directions.

[0003] In traditional centralized and local feeder automation modes, the intelligent terminals on the distribution lines do not store feeder topology information. The static topology of the feeders is stored in the master station and the dynamic topology is calculated using a topology recognition algorithm. When the topology of the distribution line changes, the distribution network updates the complete topology of the feeders in the master station. Although the distribution network in this mode has complete topology information, the topology information can only be processed and used in the master station, resulting in low efficiency in fault detection and self-healing. With the increasing scale, complexity and intelligence of the power grid, traditional centralized feeder automation and local feeder automation methods are difficult to meet the needs of accurately troubleshooting line faults. Moreover, in the face of sudden faults, traditional feeder automation technology solutions are unable to achieve fast and accurate fault location and self-healing.

[0004] The application of stack topology identification technology in the field of distribution network fault self-healing technology delegates decision-making and execution functions to individual devices in the distribution network. This technology offers advantages such as rapid fault location, automatic fault isolation, rapid power restoration, simplified management and operation, improved reliability and redundancy, and optimized energy efficiency and load balancing. Therefore, stack topology identification has become a key technical means and tool for distribution network fault self-healing. Summary of the Invention

[0005] The present invention provides a distribution network fault self-healing method and system based on stacking topology, which realizes rapid and accurate fault location, fault isolation and power restoration in an active distribution network.

[0006] In order to solve the above technical problems, the present invention provides a distribution network fault self-healing method based on a stacking topology, comprising:

[0007] The current of each node in the distribution network is obtained through each smart terminal, and the abnormality of the current of each node is determined according to a preset current threshold; wherein each node is equipped with a switch and a smart terminal;

[0008] The smart terminals are stacked and connected, and a stacking topology of the distribution network is generated according to the network topology information of the smart terminals, and the information interaction between the smart terminals is controlled by the stacking topology of the distribution network;

[0009] Based on the current of each node and the network topology information, information exchange between each node is performed through the intelligent terminal to obtain fault location;

[0010] Based on the fault location, the intelligent terminal controls the switches of nodes in the fault area to isolate the fault and obtain fault isolation information;

[0011] Based on the fault isolation information, the status of each switch is controlled through the intelligent terminal to restore the power supply of the distribution network.

[0012] The present invention stacks multiple management devices connected to the distribution network so that they can share processing tasks and improve the efficiency of data processing; the use of stacking topology technology can also ensure the connectivity of the distribution network, avoiding the paralysis of the entire distribution network caused by the failure of a single node, thereby improving the reliability of the distribution network system; through the intelligent terminal to achieve information interaction, it can realize fast data transmission and communication, respond to changing needs and optimize operation more quickly, and improve the response speed and efficiency of the system; control the fault location, fault isolation and power restoration performed by the intelligent terminal, simplify the location process, and improve the fault location accuracy and rate.

[0013] Furthermore, the current of each node in the distribution network is obtained through each smart terminal, and the abnormality of the current of each node is determined according to a preset current threshold, specifically:

[0014] The current of each node in the distribution network is collected through sensors of each intelligent terminal;

[0015] The abnormality of the current of each node is determined according to a preset current threshold; when the current of the node exceeds the preset current threshold, the current of the node is in an abnormal state, and a fault point exists downstream of the node; when the current of the node does not exceed the preset current threshold, the current of the node is in a normal state, and no fault point exists downstream of the node.

[0016] Furthermore, the smart terminals are stacked and connected, and a stacking topology of the distribution network is generated according to the network topology information of each smart terminal. The information interaction between the smart terminals is controlled by the stacking topology of the distribution network, specifically:

[0017] Stack and connect each smart terminal according to preset rules;

[0018] Transmitting network topology information through the stacked connection structure between each intelligent terminal; wherein the network topology information includes static network topology information and dynamic network topology information, the static network topology information includes the intelligent terminal IP address, communication instructions and topology query instructions, and the dynamic network topology information includes topology query instructions and result return instructions;

[0019] After each intelligent terminal completes the transmission of network topology information, the local network topology information and switch status information are transmitted between the intelligent terminals according to the GOOSE communication protocol;

[0020] A stacking topology of the distribution network is generated according to the network topology information of each smart terminal, and information interaction between the smart terminals is controlled through the stacking topology of the distribution network.

[0021] Furthermore, the information exchange between the nodes is performed through the intelligent terminal based on the current of each node and the network topology information to obtain the fault location, specifically:

[0022] Based on the current of each node and the network topology information, information exchange is performed between the nodes through the intelligent terminal, so that each node obtains the switch position and overcurrent information of the adjacent node through the intelligent terminal;

[0023] The location of the faulty node is determined based on the overcurrent information of the adjacent nodes; if the node collects the overcurrent information of the adjacent nodes through the intelligent terminal, then there is no fault in the adjacent nodes of the node; if the node does not collect the overcurrent information of the adjacent nodes through the intelligent terminal, then there is a fault in the adjacent nodes of the node.

[0024] Furthermore, based on the fault location, the intelligent terminal controls the switches of nodes in the fault area to isolate the fault and obtain fault isolation information, specifically:

[0025] If any fault node in the fault area is a circuit switch endpoint and the phase current or zero-sequence current of the fault node as the circuit switch endpoint exceeds a preset value, then when the fault node as the circuit switch endpoint only receives a "node fault" GOOSE signal sent by one side, after a preset fault clearing delay, the switch of the fault node as the circuit switch endpoint is controlled by the intelligent terminal to perform a tripping operation;

[0026] If any fault node in the fault area is the last node of the circuit and the phase current or zero-sequence current of the fault node as the last node of the circuit exceeds a preset value, then when the fault node as the last node of the circuit receives any "node fault" GOOSE signal, after a preset fault clearing delay, the switch of the fault node as the last node of the circuit is controlled by the intelligent terminal to perform a tripping operation;

[0027] If there is a non-faulty node in the fault area, when the non-faulty node only receives the "node fault" GOOSE signal sent by one side, after the preset fault clearing delay, the switch of the non-faulty node is controlled by the intelligent terminal to perform a tripping operation.

[0028] The present invention generates a stacked topology structure of the distribution network through stacking topology technology. Based on the clarity and compactness of the structure, it is easy to determine the fault path, achieve faster fault detection, fault location and fault isolation, thereby reducing the scope and duration of fault impact.

[0029] Furthermore, after the intelligent terminal controls the switches of the faulty node as the end point of the circuit switch, the faulty node as the last node of the circuit, and the node where no fault occurs to perform a tripping operation, the method further includes:

[0030] Detecting the switch tripping status of the faulty node serving as the circuit switch end point, the faulty node serving as the circuit last node, and the node where no fault occurs;

[0031] If the switches of the faulty node as the circuit switch end point, the faulty node as the last node of the circuit, and the nodes where no fault occurs are not all tripped, a "switch refuses to trip" GOOSE signal is triggered, and fault isolation information is output;

[0032] If the switches of the faulty node serving as the circuit switch end point, the faulty node serving as the circuit's last node, and the node not having a fault are all in the disconnected state and no current flows through, a "fault isolation successful" GOOSE signal is triggered and fault isolation information is output.

[0033] Furthermore, the state of each switch is controlled by the intelligent terminal according to the fault isolation information to restore the power supply of the distribution network, specifically:

[0034] Based on the fault isolation information, the intelligent terminal controls the switches in the area surrounding the fault and maintains the load in the upstream area according to the load strategy;

[0035] The load strategy is specifically as follows:

[0036]

[0037] Where f represents the total outage load in the non-fault area, n represents the total number of feeder sections in the downstream area of the fault, and λ i Represents the weight coefficient of power outage load, P i Represents the size of the power outage load;

[0038] Through the intelligent terminal, each node in the downstream area of the fault is controlled to send a GOOSE signal of fault isolation success to both sides of the node and perform the switch opening operation to restore the power supply of the distribution network.

[0039] The present invention provides multiple working paths based on a stacking topology structure, thereby reducing the possibility of a single path failure causing a failure of the entire system; and provides multiple fault paths, thereby improving the efficiency of fault isolation and fault self-healing.

[0040] Based on the above method embodiment, the present invention provides a corresponding system embodiment, which provides a distribution network fault self-healing system based on a stacking topology, including: a current detection module, a stacking topology module, a fault location module, a fault isolation module and a power restoration module;

[0041] The current detection module is used to obtain the current of each node in the distribution network through each smart terminal, and determine the abnormality of the current of each node according to a preset current threshold; wherein each node is configured with a switch and a smart terminal;

[0042] The stacking topology module is used to stack the smart terminals, generate a stacking topology of the distribution network based on the network topology information of the smart terminals, and control the information interaction between the smart terminals through the stacking topology of the distribution network;

[0043] The fault location module is configured to perform information exchange between nodes through an intelligent terminal based on the current of each node and the network topology information to obtain fault location;

[0044] The fault isolation module is configured to isolate the fault by controlling the switches of nodes in the fault area through the intelligent terminal based on the fault location, and obtain fault isolation information;

[0045] The power restoration module is used to control the status of each switch through the intelligent terminal according to the fault isolation information to restore the power supply of the distribution network.

[0046] Furthermore, the fault location module includes: an information interaction unit and a node location unit;

[0047] The information exchange unit is configured to perform information exchange between nodes through an intelligent terminal based on the current of each node and the network topology information, so that each node obtains the switch position and overcurrent information of an adjacent node through the intelligent terminal;

[0048] The node positioning unit is used to determine the location of the faulty node based on the overcurrent information of the adjacent nodes; if the node collects the overcurrent information of the adjacent nodes through the intelligent terminal, then there is no fault in the adjacent nodes of the node; if the node does not collect the overcurrent information of the adjacent nodes through the intelligent terminal, then there is a fault in the adjacent nodes of the node.

[0049] Furthermore, the fault isolation module includes: a first unit, a second unit and a third unit;

[0050] The first unit is configured to, if any fault node in the fault area is a circuit switch endpoint and the phase current or zero-sequence current of the fault node as the circuit switch endpoint exceeds a preset value, then when the fault node as the circuit switch endpoint only receives a "node fault" GOOSE signal sent by one side, control the switch of the fault node as the circuit switch endpoint to perform a tripping operation through the intelligent terminal after a preset fault clearing delay;

[0051] The second unit is configured to, if any fault node in the fault area is the last node of the circuit and the phase current or zero-sequence current of the fault node as the last node of the circuit exceeds a preset value, then when the fault node as the last node of the circuit receives any "node fault" GOOSE signal, after a preset fault clearing delay, control the switch of the fault node as the last node of the circuit to perform a tripping operation through the intelligent terminal;

[0052] The third unit is used to control the switch of the non-faulty node to perform a tripping operation through the intelligent terminal after a preset fault clearing delay if there is a non-faulty node in the fault area, when the non-faulty node only receives the "node fault" GOOSE signal sent by one side. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 : A flow chart of an embodiment of a distribution network fault self-healing method based on a stacking topology provided by the present invention;

[0054] Figure 2 : An application structure diagram of an embodiment of a distribution network fault self-healing method based on a stacking topology provided by the present invention;

[0055] Figure 3 : A structural diagram of an embodiment of a distribution network fault self-recovery system based on a stacking topology provided by the present invention. DETAILED DESCRIPTION

[0056] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0057] In the description of this application, it should be understood that the terms "first," "second," and "third" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature defined as "first," "second," and "third" may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, "several" means two or more.

[0058] The present invention provides a distribution network fault self-healing method and system based on stacking topology, which realizes rapid and accurate fault location, fault isolation and power restoration in an active distribution network.

[0059] Example 1

[0060] Based on the above requirements, an embodiment of the present invention provides a distribution network fault self-healing method based on a stacking topology. The method flow is as follows: Figure 1 As shown, the method includes steps S1 to S5, and each step is specifically as follows:

[0061] S1. Obtain the current of each node in the distribution network through each smart terminal, and determine the abnormality of the current of each node based on the preset current threshold; each node is equipped with a switch and a smart terminal. This step includes steps S1.1 to S1.2, and the details of each step are as follows:

[0062] S1.1. Collect the current of each node in the distribution network through the sensors of each smart terminal.

[0063] The distribution network to be tested consists of several nodes, each equipped with a switch and an intelligent terminal. Each intelligent terminal has built-in sensors and a communication module. When detecting fault currents in the distribution network, each intelligent terminal first uses its built-in sensors to collect the current flowing through its corresponding node in real time, thereby obtaining the current at each node in the distribution network. Each intelligent terminal then transmits the collected current at each node to the distribution network data center via its built-in communication module. Finally, the data center processes the current at each node, including but not limited to filtering, sampling, and transformation operations. Data classification and analysis are then performed to extract meaningful features from the current data and calculate statistical indicators and frequency domain features.

[0064] S1.2. Determine the abnormality of the current of each node according to a preset current threshold; when the current of the node exceeds the preset current threshold, the current of the node is in an abnormal state, and there is a fault point downstream of the node; when the current of the node does not exceed the preset current threshold, the current of the node is in a normal state, and there is no fault point downstream of the node.

[0065] A current threshold is set in the data center, and abnormal current conditions of the nodes are determined based on the preset current threshold. The current threshold can be flexibly adjusted according to the actual conditions and detection requirements of the distribution network.

[0066] When it is detected that the current of a node exceeds the preset current threshold, the current of the node is in an abnormal state and there is a fault point downstream of the node; when it is detected that the current of the node does not exceed the preset current threshold, the current of the node is in a normal state and there is no fault point downstream of the node.

[0067] S2. Stack the smart terminals and generate a distribution network stacking topology based on the network topology information of each smart terminal. The information exchange between the smart terminals is controlled by the distribution network stacking topology. This step includes steps S2.1 to S2.4. The details of each step are as follows:

[0068] S2.1. Stack and connect the smart terminals according to preset rules.

[0069] The embodiments of the present invention set connection rules based on actual needs. According to the preset rules, each intelligent terminal is stacked and connected to form a centrally managed network structure. This generates a stacking device master (SDM) that manages and controls the query process for the entire stacking topology based on the stacking topology information. According to the preset rules, each network device in the distribution network is stacked and connected to form an independently operating logical unit that can be uniformly configured and managed by the master device.

[0070] S2.2. Transmit network topology information through the stacked connection structure between each smart terminal; wherein, the network topology information includes static network topology information and dynamic network topology information, the static network topology information includes the smart terminal IP address, communication instructions and topology query instructions, and the dynamic network topology information includes topology query instructions and result return instructions.

[0071] Static network topology information is transmitted through the stacking connection structure between each intelligent terminal, specifically:

[0072] First, each smart terminal is preconfigured with its own smart terminal information and the IP addresses of neighboring smart terminals. Next, the smart terminal corresponding to the substation's outgoing line switch is set as smart terminal A. Based on the stacking connection structure between smart terminals, the smart terminal connected to smart terminal A is set as smart terminal 1, and the smart terminal connected to smart terminal 1 is set as smart terminal 2. This continues until all smart terminals are configured. The topology query endpoint is smart terminal N. Finally, smart terminal A sends a communication command and a topology query command to smart terminal 1, and smart terminal 1 sends a topology query command to smart terminal 2.

[0073] Dynamic network topology information is transmitted through the stacking connection structure between each intelligent terminal, specifically:

[0074] First, after completing the transmission of static network topology information, smart terminal 2 receives the topology query instruction sent by smart terminal 1 and forwards the topology query instruction to smart terminal 3; smart terminal 3 receives the topology query instruction sent by smart terminal 2 and forwards the topology query instruction to smart terminal 4... until smart terminal N receives the topology query instruction sent by smart terminal N-1.

[0075] Next, after receiving the topology query command, smart terminal N sends a result return command, along with smart terminal N's local network topology information and switch status information, to smart terminal N-1. After receiving the result return command, smart terminal N-1 sends the result return command, along with the local network topology information from smart terminal N-1 to smart terminal N, and switch status information, to smart terminal N-2. After receiving the result return command, smart terminal 3 sends the result return command, along with the local network topology information from smart terminal 3 to smart terminal N, and switch status information, to smart terminal 2. After receiving the result return command, smart terminal 2 sends the local network topology information from smart terminal 2 to smart terminal N, and switch status information, to smart terminal 1.

[0076] Finally, the query process of the entire stack topology is managed and controlled by the stack topology master device SDM.

[0077] S2.3. After each smart terminal completes transmitting the network topology information, the local network topology information and switch status information are transmitted between the smart terminals according to the GOOSE communication protocol.

[0078] First, each smart terminal pre-configures its own smart terminal information and the IP address of the adjacent smart terminal. Secondly, the local network topology information and switch status information are transmitted between adjacent smart terminals through the GOOSE (Global Inter-Station Express Message) communication protocol. Then, through the GOOSE communication protocol, each smart terminal transmits topology query instructions about local network topology information and switch status information from front to back in the order of stacking connection. When transmitting the above-mentioned topology query instructions, there is no need to immediately return the queried local network topology information and switch status information. Among them, the switch status information includes the position status information of the switch, the operating status information of the switch, etc. Finally, after the query instruction of the entire stacking topology is transmitted, each smart terminal returns its own local network topology information and switch status information from back to front in the order of stacking connection, thereby realizing information interaction among each smart terminal.

[0079] S2.4. Generate a stacking topology of the distribution network based on the network topology information of each smart terminal, and control information interaction between the smart terminals through the stacking topology of the distribution network.

[0080] In this embodiment of the present invention, based on steps S2.1 to S2.3 above, a stacked topology of the distribution network is generated based on the network topology information of each smart terminal. This stacked topology of the distribution network controls the query requests and result returns of local network topology information and switch status information between the smart terminals, thereby enabling information exchange between the smart terminals.

[0081] S3. Based on the current of each node and the network topology information, information exchange between nodes is performed through the intelligent terminal to obtain fault location. This step includes steps S3.1 to S3.2. The details of each step are as follows:

[0082] S3.1. Based on the current of each node and the network topology information, information exchange is performed between the nodes through the intelligent terminal, so that each node obtains the switch position and overcurrent information of the adjacent node through the intelligent terminal.

[0083] Based on the current of each node and the network topology information, information is exchanged between the nodes via the intelligent terminal. The exchanged information includes switch position information and overcurrent information for each node. After the exchange of information between the nodes is complete, each node successfully obtains the switch position and overcurrent information of its neighboring nodes via the intelligent terminal.

[0084] S3.2. Determine the location of the faulty node based on the overcurrent information of the adjacent nodes; if the node collects the overcurrent information of the adjacent nodes through the intelligent terminal, then there is no fault in the adjacent nodes of the node; if the node does not collect the overcurrent information of the adjacent nodes through the intelligent terminal, then there is a fault in the adjacent nodes of the node.

[0085] The fault node location is determined based on the overcurrent information of the adjacent nodes. If several adjacent switches are monitored by the same intelligent terminal, such as a ring network cabinet switch, the intelligent terminal can directly detect whether a fault current flows through each adjacent switch. If several adjacent switches are monitored by different intelligent terminals, it is necessary to communicate with the intelligent terminals of the adjacent nodes to obtain the overcurrent information of the adjacent nodes, thereby completing the node location of the distribution network fault. If the node collects the overcurrent information of the adjacent nodes through the intelligent terminal, then there is no fault in the adjacent nodes of the node; if the node does not collect the overcurrent information of the adjacent nodes through the intelligent terminal, then there is a fault in the adjacent nodes of the node.

[0086] S4. Based on the fault location, the intelligent terminal controls the switches of the nodes in the fault area to isolate the fault and obtain fault isolation information. This step includes steps S4.1 to S4.2. The details of each step are as follows:

[0087] S4.1. Based on the fault location, according to the node attributes and node status of the nodes in the fault area, the intelligent terminal controls the switches of the nodes in the fault area to perform corresponding operations to isolate the fault.

[0088] If any faulty node in the fault area is a circuit breaker endpoint and the phase current or zero-sequence current at the faulty node exceeds a preset value, then, if the faulty node receives a "node fault" GOOSE signal from only one side, the intelligent terminal controls the switch at the faulty node to trip after a preset fault-clearing delay. The circuit breaker endpoint means that the distribution network has only one switch, with no other switches behind it to control current flow or disconnect the circuit.

[0089] If any fault node in the fault area is the last node of the circuit and the phase current or zero-sequence current of the fault node as the last node of the circuit exceeds a preset value, then when the fault node as the last node of the circuit receives any "node fault" GOOSE signal, after a preset fault clearing delay, the switch of the fault node as the last node of the circuit is controlled by the intelligent terminal to perform a tripping operation.

[0090] If there is a non-faulty node in the fault area, when the non-faulty node only receives the "node fault" GOOSE signal sent by one side, after the preset fault clearing delay, the switch of the non-faulty node is controlled by the intelligent terminal to perform a tripping operation.

[0091] S4.2. After the intelligent terminal controls the switches of the faulty node serving as the end point of the circuit switch, the faulty node serving as the last node of the circuit, and the node where no fault occurs to perform tripping operations, the triggering state of the "fault isolation successful" GOOSE signal is determined according to the tripping state of the switches of the nodes in the fault area.

[0092] Detecting the switch tripping status of the faulty node as the circuit switching end point, the faulty node as the last node of the circuit, and the node where no fault occurs:

[0093] If the switches of the faulty node as the circuit switch end point, the faulty node as the last node of the circuit, and the nodes where no fault occurs are not all tripped, a "switch refuses to trip" GOOSE signal is triggered, and fault isolation information is output;

[0094] If the switches of the faulty node serving as the circuit switch end point, the faulty node serving as the circuit's last node, and the node not having a fault are all in the disconnected state and no current flows through, a "fault isolation successful" GOOSE signal is triggered and fault isolation information is output.

[0095] S5. Based on the fault isolation information, the intelligent terminal controls the status of each switch to restore the power supply of the distribution network. This step includes steps S5.1 to S5.2. The specific steps are as follows:

[0096] S5.1. Based on the fault isolation information, the intelligent terminal controls the switches in the area surrounding the fault and maintains the load in the upstream area of the fault according to the load strategy.

[0097] The upstream area of the fault is connected to the power supply. To ensure circuit stability and load stability in the upstream area of the fault, the embodiment of the present invention formulates a load strategy based on meeting the actual operating constraints of the distribution network, and controls the switches in the area surrounding the fault through the intelligent terminal according to the above load strategy to maintain the load in the upstream area of the fault.

[0098] The load strategy is specifically as follows:

[0099]

[0100] Where f represents the total outage load in the non-fault area, n represents the total number of feeder sections in the downstream area of the fault, and λ i Represents the weight coefficient of power outage load, P i Represents the size of the power outage load.

[0101] S5.2. Use the smart terminal to control each node in the downstream area of the fault to send a GOOSE signal indicating that the fault is isolated successfully to both sides of the node and perform a switch opening operation to restore power supply to the distribution network.

[0102] After completing the fault isolation in step S4, the intelligent terminal controls each node in the downstream area of the fault to send a fault isolation success GOOSE signal to both sides of the node and executes the switch opening operation to gradually restore power supply. After the power supply of each node in the downstream area of the fault is restored, when the voltage on the power supply side and the load side is lost, the power supply side and the load side receive the sent fault isolation success GOOSE signal, open the switches of the nodes in the power supply side and load side areas after a preset delay, and restore power supply to the distribution network.

[0103] On the basis of the above method steps, the embodiment of the present invention further applies a distribution network fault self-healing method based on a stacking topology.

[0104] The application structure diagram of the distribution network fault self-recovery method based on stacking topology is as follows: Figure 2 As shown in the figure, CB1 and CB2 are substation outgoing switches, SW1, SW2, SW3, and SW4 are a set of sectionalizing switches, SW6 and SW7 are a set of sectionalizing switches, SW5 is a contact switch, DG1 and DG2 are distributed power sources, and STUA, STU1, STU2, STU3, STU4, STU5, STU6, STU7, and STUB are intelligent terminals. In this embodiment of the present invention, to meet the requirements of rapid operation and response, all sectionalizing switches are circuit breakers.

[0105] When a distribution network fault occurs, the smart terminal corresponding to the node upstream of the fault node will detect that the current flowing through the node is greater than a preset threshold, indicating an abnormal state. Specifically, the phase current collected by the node is greater than a preset threshold or the zero-sequence current is greater than a preset threshold.

[0106] All smart terminals in the distribution network are pre-configured with their own smart terminal information and the IP addresses of adjacent smart terminals. Communication between smart terminals can be achieved based on the IP addresses of adjacent smart terminals.

[0107] Configure static network topology information for each intelligent terminal in the distribution network: First, STU1 communicates with STUA to confirm that the switch monitored by STUA is the substation outgoing line switch. Then, STU1 sends a topology query command to STU2.

[0108] Configure dynamic network topology information for each intelligent terminal in the distribution network: After receiving a topology query command from STU1, STU2 does not immediately return the local network topology information and switch status information. Instead, it forwards the topology query command to STU3. After receiving a topology query command from STU2, STU3 does not immediately return the local network topology information and switch status information. Instead, it forwards the topology query command to STU4. After receiving a topology query command from STU3, STU4 does not immediately return the local network topology information and switch status information. Instead, it forwards the topology query command to STU5. At this point, topology query commands cease, and STU5 returns its local network topology information and switch status information to STU4. STU4 returns the local network topology information and switch status information of STU4 and STU5 to STU3. STU3 returns the local network topology information and switch status information of STU3, STU4, and STU5 to STU2. STU2 returns the local network topology information and switch status information of STU2, STU3, STU4 and STU5 to STU1.

[0109] Local network topology information and switch status information are transmitted between each intelligent terminal according to the GOOSE communication protocol. The master device SDM of the stack topology is responsible for initiating topology query instructions and coordinating information exchange between each intelligent terminal. Specifically, the master device SDM sends the topology query instruction to STU2, and then the intelligent terminal forwards the query instruction to STU3, STU4 and STU5 in turn until the end point of the topology query is reached. When the query instruction reaches the end point STU5, the master device SDM receives the local network topology information and switch status information returned by STU5, and then collects and summarizes the local network topology information and switch status information of other intelligent terminals (STU4, STU3 and STU2) in turn. Finally, the master device SDM summarizes the local network topology information and switch status information of itself and each intelligent terminal, as well as the connection relationship between each intelligent terminal, and returns the result to STU1, completing the entire topology query process.

[0110] In this embodiment of the present invention, substation outgoing switch CB1 and circuit breaker SW1 can both detect overcurrent faults, while circuit breakers SW3, SW4, and SW5 cannot detect short-circuit faults. CB1 sends detected fault information to SW1. SW1 sends detected fault information to SW2 and CB1. SW2 does not detect fault information from SW1 and SW3. SW3 does not detect a fault and sends a non-fault detection message to SW2 and SW4. SW4 does not detect a fault and sends a non-fault detection message to SW3.

[0111] Based on the above fault information, CB1 can detect the fault and receive information that SW1 has detected the fault. SW1 detects the fault detected by CB1 and receives information that CB1 has detected the fault. SW2 does not detect the fault and receives information that SW1 has detected the fault and information that SW3 has not detected the fault. SW3 does not detect the fault and receives information that SW2 has not detected the fault and information that SW4 has not detected the fault. SW4 does not detect the fault and receives information that SW3 has not detected the fault. In summary, SW1 determines that the fault location is downstream of SW1, and SW2 determines that the fault location is upstream of SW2. Therefore, it can be determined that the fault occurs in the distribution area between circuit breakers SW1 and SW2, and fault location is complete.

[0112] According to the fault location information, in the embodiment of the present invention, the switch corresponding to a node in the fault area is the last switch SW1, which is the end point of the circuit, and the phase current or zero-sequence current of STU1 exceeds the preset value. There are no nodes on the left and right sides of STU1. STU1 only receives the "node fault" GOOSE signal sent by one side. Then, after the preset fault clearing delay, the switch SW1 of the node is controlled by STU1 to perform a tripping operation. In the embodiment of the present invention, if the phase current or zero-sequence current of a node in the fault area exceeds the preset value, then after the preset fault clearing delay, the switch SW2 of the node is controlled by STU1 to perform a tripping operation. Based on the above steps, the circuit breakers SW1 and SW2 are tripped by controlling the intelligent terminal to complete the fault isolation.

[0113] After the fault is isolated successfully, each node in the fault area triggers the "fault isolation successful" GOOSE signal in turn and forwards the "fault isolation successful" GOOSE signal to both sides.

[0114] After circuit breaker SW2 trips and isolates the fault, contactor switch SW5 loses voltage due to the faulty area. This means the faulty area is outside the distribution area centered on the contactor switch. In the electrical area, contactor switch SW5 is closed, restoring power to the healthy area on the faulty side, completing the self-healing of the distribution network.

[0115] The implementation of the above embodiments of the present invention has the following beneficial effects:

[0116] The present invention provides a distribution network fault self-healing method based on stacking topology, which stacks multiple management devices connected to the distribution network so that they can share processing tasks and improve the efficiency of data processing. The use of stacking topology technology can also ensure the connectivity of the distribution network, avoid paralysis of the entire distribution network caused by a single node failure, and thus improve the reliability of the distribution network system. Information interaction is achieved through intelligent terminals, which can achieve rapid data transmission and communication, respond more quickly to changing needs and optimize operation, and improve the response speed and efficiency of the system. The intelligent terminal controls the fault location, fault isolation and power restoration performed, simplifies the location process, and improves the fault location accuracy and rate.

[0117] Example 2

[0118] Based on the content of the above embodiments, an embodiment of the present invention provides a distribution network fault self-healing system based on a stacking topology, including: a current detection module 101, a stacking topology module 102, a fault location module 103, a fault isolation module 104 and a power recovery module 105. The system structure is as follows Figure 3 shown.

[0119] The current detection module 101 is used to obtain the current of each node in the distribution network through each smart terminal and determine the abnormality of the current of each node according to a preset current threshold; wherein each node is configured with a switch and a smart terminal;

[0120] The stacking topology module 102 is used to stack the smart terminals, generate a stacking topology of the distribution network based on the network topology information of the smart terminals, and control the information interaction between the smart terminals through the stacking topology of the distribution network;

[0121] The fault location module 103 is configured to perform information exchange between nodes through an intelligent terminal based on the current of each node and the network topology information to obtain fault location;

[0122] The fault isolation module 104 is configured to isolate the fault by controlling the switches of nodes in the fault area through the intelligent terminal based on the fault location, and obtain fault isolation information;

[0123] The power restoration module 105 is used to control the status of each switch through the intelligent terminal according to the fault isolation information to restore the power supply of the distribution network.

[0124] In a possible implementation, the current detection module 101 includes: a current acquisition unit 201 and an abnormality detection unit 202;

[0125] The current collection unit 201 is used to collect the current of each node in the power distribution network through the sensor of each smart terminal;

[0126] The abnormality detection unit 202 is used to determine the abnormality of the current of each node based on a preset current threshold; when the current of the node exceeds the preset current threshold, the current of the node is in an abnormal state, and there is a fault point downstream of the node; when the current of the node does not exceed the preset current threshold, the current of the node is in a normal state, and there is no fault point downstream of the node.

[0127] In a possible implementation, the stack topology module 102 includes: a connection unit 301, a topology information unit 302, a communication unit 303, and a terminal interaction unit 304;

[0128] The connection unit 301 is used to stack and connect the smart terminals according to preset rules;

[0129] The topology information unit 302 is used to transmit network topology information through the stacked connection structure between each intelligent terminal; wherein the network topology information includes static network topology information and dynamic network topology information, the static network topology information includes the intelligent terminal IP address, communication instructions and topology query instructions, and the dynamic network topology information includes topology query instructions and result return instructions;

[0130] The communication unit 303 is used to transmit local network topology information and switch status information between the smart terminals according to the GOOSE communication protocol after the smart terminals complete the transmission of network topology information;

[0131] The terminal interaction unit 304 is configured to generate a stacking topology of the distribution network according to the network topology information of each smart terminal, and control information interaction between the smart terminals through the stacking topology of the distribution network.

[0132] In a possible implementation, the fault location module 103 includes: an information interaction unit 401 and a node location unit 402;

[0133] The information exchange unit 401 is configured to perform information exchange between nodes through an intelligent terminal based on the current of each node and the network topology information, so that each node obtains the switch position and overcurrent information of an adjacent node through the intelligent terminal;

[0134] The node positioning unit 402 is used to determine the location of the faulty node based on the overcurrent information of the adjacent nodes; if the node collects the overcurrent information of the adjacent nodes through the intelligent terminal, then there is no fault in the adjacent nodes of the node; if the node does not collect the overcurrent information of the adjacent nodes through the intelligent terminal, then there is a fault in the adjacent nodes of the node.

[0135] In a possible implementation, the fault isolation module 104 includes: a first unit 501, a second unit 502, and a third unit 503;

[0136] The first unit 501 is configured to, if any fault node in the fault area is a circuit switch endpoint and the phase current or zero-sequence current of the fault node serving as the circuit switch endpoint exceeds a preset value, then when the fault node serving as the circuit switch endpoint receives only a "node fault" GOOSE signal sent by one side, control the switch of the fault node serving as the circuit switch endpoint to perform a tripping operation through the intelligent terminal after a preset fault clearing delay;

[0137] The second unit 502 is configured to, if any fault node in the fault area is the last node of the circuit and the phase current or zero-sequence current of the fault node as the last node of the circuit exceeds a preset value, then when the fault node as the last node of the circuit receives any "node fault" GOOSE signal, after a preset fault clearing delay, control the switch of the fault node as the last node of the circuit to perform a tripping operation through the intelligent terminal;

[0138] The third unit 503 is used to control the switch of the non-faulty node to perform a tripping operation through the intelligent terminal after a preset fault clearing delay if there is a non-faulty node in the fault area, when the non-faulty node only receives the "node fault" GOOSE signal sent by one side.

[0139] In a possible implementation, the fault isolation module 104 further includes: a triggering unit 504;

[0140] The trigger unit 504 is used to detect the switch tripping status of the fault node as the end point of the circuit switch, the fault node as the last node of the circuit, and the node where the fault has not occurred; if the switches of the fault node as the end point of the circuit switch, the fault node as the last node of the circuit, and the node where the fault has not occurred are not all tripped, a "switch refuses to trip" GOOSE signal is triggered and fault isolation information is output; if the switches of the fault node as the end point of the circuit switch, the fault node as the last node of the circuit, and the node where the fault has not occurred are all in the disconnected state and no current flows through, a "fault isolation successful" GOOSE signal is triggered and fault isolation information is output.

[0141] In a possible implementation, the power recovery module 105 includes: a load maintenance unit 601 and a power supply unit 602;

[0142] The load maintenance unit 601 is used to control the switches in the area surrounding the fault through the intelligent terminal according to the fault isolation information, and maintain the load in the upstream area of the fault according to the load strategy;

[0143] The load strategy is specifically as follows:

[0144]

[0145] Where f represents the total outage load in the non-fault area, n represents the total number of feeder sections in the downstream area of the fault, and λ i Represents the weight coefficient of power outage load, P i Represents the size of the power outage load;

[0146] The power supply unit 602 is used to control each node in the downstream area of the fault through the intelligent terminal to send a fault isolation success GOOSE signal to both sides of the node and perform a switch opening operation to restore power supply of the distribution network.

[0147] The implementation of the above embodiments of the present invention has the following beneficial effects:

[0148] The present invention provides a distribution network fault self-healing system based on a stacking topology, comprising a current detection module, a stacking topology module, a fault location module, a fault isolation module, and a power restoration module. The current detection module monitors the current at each node in the distribution network in real time; the stacking topology module enables rapid communication between smart terminals; the fault isolation module enables rapid location of faulty nodes; and the power restoration module formulates load strategies to restore power to the distribution network. This system achieves rapid and accurate fault location, fault isolation, and power restoration in active distribution networks.

[0149] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A distribution network fault self-healing method based on stacking topology, characterized in that: include: The current of each node in the distribution network is obtained through each smart terminal, and the abnormality of the current of each node is determined according to a preset current threshold; wherein each node is equipped with a switch and a smart terminal; The smart terminals are stacked and connected, and a stacking topology of the distribution network is generated according to the network topology information of the smart terminals, and the information interaction between the smart terminals is controlled by the stacking topology of the distribution network; Based on the current of each node and the network topology information, information exchange between each node is performed through the intelligent terminal to obtain fault location; Based on the fault location, the intelligent terminal controls the switches of nodes in the fault area to isolate the fault and obtain fault isolation information; Based on the fault isolation information, the intelligent terminal controls the status of each switch and restores the power supply of the distribution network; The stacking connection of the smart terminals, generating a stacking topology of the distribution network based on the network topology information of the smart terminals, and controlling the information interaction between the smart terminals through the stacking topology of the distribution network are specifically as follows: Stack and connect each smart terminal according to preset rules; Transmitting network topology information through the stacked connection structure between each intelligent terminal; wherein the network topology information includes static network topology information and dynamic network topology information, the static network topology information includes the intelligent terminal IP address, communication instructions and topology query instructions, and the dynamic network topology information includes topology query instructions and result return instructions; After each intelligent terminal completes the transmission of network topology information, the local network topology information and switch status information are transmitted between the intelligent terminals according to the GOOSE communication protocol; A stacking topology of the distribution network is generated according to the network topology information of each smart terminal, and information interaction between the smart terminals is controlled through the stacking topology of the distribution network.

2. A distribution network fault self-healing method based on stacking topology according to claim 1, characterized in that: The current of each node in the distribution network is obtained through each smart terminal, and the abnormality of the current of each node is determined according to a preset current threshold, specifically: The current of each node in the distribution network is collected through sensors of each intelligent terminal; Determining the abnormality of the current of each node according to a preset current threshold; when the current of a node exceeds the preset current threshold, the current of the node is in an abnormal state and a fault point exists downstream of the node; When the current of the node does not exceed the preset current threshold, the current of the node is in a normal state, and there is no fault point downstream of the node.

3. The method for self-healing a distribution network fault based on a stacking topology according to claim 1, wherein: The method of performing information exchange between nodes through the intelligent terminal based on the current of each node and the network topology information to obtain fault location is specifically as follows: Based on the current of each node and the network topology information, information exchange is performed between the nodes through the intelligent terminal, so that each node obtains the switch position and overcurrent information of the adjacent node through the intelligent terminal; Determining the node location of the fault based on the overcurrent information of the adjacent nodes; If the node collects the overcurrent information of the adjacent node through the intelligent terminal, then there is no fault in the adjacent node of the node; if the node does not collect the overcurrent information of the adjacent node through the intelligent terminal, then there is a fault in the adjacent node of the node.

4. The method for self-healing a distribution network fault based on a stacking topology according to claim 1, wherein: Based on the fault location, the intelligent terminal controls the switches of nodes in the fault area to isolate the fault and obtain fault isolation information, specifically: If any faulty node in the fault area is a circuit breaker endpoint and the phase current or zero-sequence current of the faulty node as the circuit breaker endpoint exceeds a preset value, then when the faulty node as the circuit breaker endpoint only receives a "node fault" GOOSE signal sent by one side, after a preset fault clearing delay, the switch of the faulty node as the circuit breaker endpoint is controlled by the intelligent terminal to perform a tripping operation; If any fault node in the fault area is the last node of the circuit and the phase current or zero-sequence current of the fault node as the last node of the circuit exceeds a preset value, then when the fault node as the last node of the circuit receives any "node fault" GOOSE signal, after a preset fault clearing delay, the switch of the fault node as the last node of the circuit is controlled by the intelligent terminal to perform a trip operation; If there are non-faulty nodes in the fault area, when the non-faulty nodes only receive the "node fault" GOOSE signal sent by one side, after the preset fault clearing delay, the switch of the non-faulty node is controlled by the smart terminal to perform a tripping operation.

5. A distribution network fault self-healing method based on stacking topology according to claim 4, characterized in that: After the intelligent terminal controls the switches of the fault node as the end point of the circuit switch, the fault node as the last node of the circuit, and the node where the fault does not occur to perform a tripping operation, the method further includes: Detecting the switch tripping status of the faulty node as the switching end point of the circuit, the faulty node as the last node of the circuit, and the node where no fault occurs; If the switches of the faulty node as the end point of the circuit switch, the faulty node as the last node of the circuit, and the node where no fault occurs are not all tripped, a "switch refuses to trip" GOOSE signal is triggered and fault isolation information is output; If the switches of the faulty node as the end point of the circuit switch, the faulty node as the last node of the circuit, and the node that has not failed are all in the open state and no current flows, the "fault isolation successful" GOOSE signal is triggered and the fault isolation information is output.

6. A distribution network fault self-healing system based on stacking topology, characterized in that: include: Current detection module, stacking topology module, fault location module, fault isolation module and power restoration module; The current detection module is used to obtain the current of each node in the distribution network through each smart terminal, and determine the abnormality of the current of each node according to a preset current threshold; wherein each node is configured with a switch and a smart terminal; The stacking topology module is used to stack the smart terminals, generate a stacking topology of the distribution network based on the network topology information of the smart terminals, and control the information interaction between the smart terminals through the stacking topology of the distribution network; The fault location module is configured to perform information exchange between nodes through an intelligent terminal based on the current of each node and the network topology information to obtain fault location; The fault isolation module is configured to isolate the fault by controlling the switches of nodes in the fault area through the intelligent terminal based on the fault location, and obtain fault isolation information; The power restoration module is used to control the status of each switch through the intelligent terminal according to the fault isolation information to restore the power supply of the distribution network; The stacking topology module includes: a connection unit, a topology information unit, a communication unit and a terminal interaction unit; The connection unit is used to stack and connect the smart terminals according to preset rules; The topology information unit is used to transmit network topology information through the stacked connection structure between each intelligent terminal; wherein the network topology information includes static network topology information and dynamic network topology information, the static network topology information includes the intelligent terminal IP address, communication instructions and topology query instructions, and the dynamic network topology information includes topology query instructions and result return instructions; The communication unit is used to transmit local network topology information and switch status information between the smart terminals according to the GOOSE communication protocol after the smart terminals complete the transmission of network topology information; The terminal interaction unit is used to generate a stacking topology of the distribution network according to the network topology information of each smart terminal, and control the information interaction between the smart terminals through the stacking topology of the distribution network.

7. A distribution network fault self-healing system based on stacking topology according to claim 6, characterized in that: The fault location module includes: an information interaction unit and a node location unit; The information exchange unit is configured to perform information exchange between nodes through an intelligent terminal based on the current of each node and the network topology information, so that each node obtains the switch position and overcurrent information of an adjacent node through the intelligent terminal; The node positioning unit is used to determine the location of the faulty node based on the overcurrent information of the adjacent nodes; if the node collects the overcurrent information of the adjacent nodes through the intelligent terminal, then there is no fault in the adjacent nodes of the node; if the node does not collect the overcurrent information of the adjacent nodes through the intelligent terminal, then there is a fault in the adjacent nodes of the node.

8. The distribution network fault self-healing system based on stacking topology according to claim 6, characterized in that: The fault isolation module includes: a first unit, a second unit and a third unit; The first unit is configured to, if any faulty node in the fault area is a circuit breaker endpoint and the phase current or zero-sequence current of the faulty node as the circuit breaker endpoint exceeds a preset value, then, when the faulty node as the circuit breaker endpoint receives only a "node fault" GOOSE signal sent by one side, control the switch of the faulty node as the circuit breaker endpoint to perform a tripping operation through the intelligent terminal after a preset fault clearing delay; The second unit is configured to, if any fault node in the fault area is the last node of the circuit and the phase current or zero-sequence current of the fault node as the last node of the circuit exceeds a preset value, then when the fault node as the last node of the circuit receives any "node fault" GOOSE signal, after a preset fault clearing delay, control the switch of the fault node as the last node of the circuit to perform a tripping operation through the intelligent terminal; The third unit is configured to, if there is a non-faulty node in the fault area, control the switch of the non-faulty node through the intelligent terminal to perform a tripping operation after a preset fault clearing delay when the non-faulty node receives a "node fault" GOOSE signal sent by only one side.

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