Power distribution network power and communication coordination method under extreme disasters

Abstract

The invention discloses a power distribution network electric power and communication coordination method under extreme disasters, and relates to the technical field of electric power operation and maintenance, and the method comprises the steps: S1, constructing a power distribution network electric power-communication system structure model; s2, determining a communication system recovery strategy; s3, the robustness of the STU communication module is improved; and S4, formulating a coordination recovery strategy of the power distribution network power and the communication system. Through coordination recovery of the power distribution network power and the communication system, the power distribution network power and the communication system can be rapidly recovered after a disaster occurs, the power failure and communication interruption time is shortened, and the recovery speed of the whole system is improved; meanwhile, the research of the recovery strategy can formulate corresponding response schemes for different extreme disaster situations, the robustness and reliability of the system are improved, the influence of the disaster on the system is reduced, the power distribution network power and communication system can also be recovered in the disaster within a short time, the loss of enterprises and users caused by power failure and communication faults can be reduced, and the economic benefits of the enterprises and the users are improved. And the continuity of production and business is protected.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power operation and maintenance, and in particular to a method for coordinating power and communication of a distribution network under extreme disasters. Background Art

[0003] Extreme disasters cause large-scale failures in the power and communication systems of the distribution network in the area they pass through, seriously affecting the stability of power supply, and even causing large-scale power outages, resulting in adverse social impacts and immeasurable economic losses. In the process of power grid recovery after extreme disasters, the recovery of the power system generally precedes the recovery of the communication information system, and there is a lack of coordination between the two. However, coordination between the two may lead to more effective and rapid recovery of the system. The current distribution network recovery strategy is usually implemented through grid reconstruction and fault repair. In the study of the distribution network recovery process, the impact of the distribution network communication system has not been taken into account. In the actual power grid, grid reconstruction depends on the dispatching automation of the distribution network communication system, and fault recovery also depends on the location and isolation of power faults by the communication system. The formulated post-disaster recovery strategy often fails to achieve the expected results.

[0004] Therefore, it is necessary to design a power and communication coordination method for distribution networks under extreme disasters to solve the above technical problems. Summary of the invention

[0005] In response to the above problems, the present application provides a method for coordinating power and communications of a distribution network under extreme disasters. By coordinating the restoration of the power and communications systems of the distribution network, the power and communications systems of the distribution network can be quickly restored after a disaster occurs, shortening the time of power outages and communication interruptions, and improving the recovery speed of the overall system. At the same time, the research on recovery strategies can formulate corresponding response plans for different extreme disaster scenarios, improve the robustness and reliability of the system, and reduce the impact of disasters on the system. The power and communications systems of the distribution network can also be restored in a short time during a disaster, which can reduce the losses of enterprises and users caused by power outages and communication failures and protect the continuity of production and business.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for coordinating power and communication of a distribution network under extreme disasters, comprising the following steps:

[0007] S1. Analyze the ways and mechanisms of distribution network system failures caused by extreme disasters, and build a distribution network power-communication system structure model;

[0008] S2. Select a variety of emergency repair methods according to the actual needs of the site and determine the communication system recovery strategy based on the mobile self-organizing system architecture;

[0009] S3, using LoRa-based narrowband wireless ad hoc networking technology to improve the robustness of the STU communication module;

[0010] S4. Based on the mutual conversion relationship between distribution network communication restoration and power fault restoration, formulate a coordinated restoration strategy for distribution network power and communication systems under extreme disasters.

[0011] Further, preferably, the distribution network system failure includes a power system failure and a communication system failure.

[0012] Further, preferably, the emergency repair method includes but is not limited to the use of optical fiber emergency repair, mobile base station emergency repair and emergency communication vehicle.

[0013] Furthermore, preferably, the mobile self-organizing system structure is a two-layer cluster structure, wherein the upper layer nodes are only connected to the cluster head node, and the nodes within the cluster communicate with the upper layer nodes through the cluster head node.

[0014] Further, preferably, the communication system recovery strategy of the mobile self-organizing architecture includes the following steps:

[0015] S1. Use the space-time grid fusion method, add pre-disaster prediction, divide the disaster-stricken area into small grids, encode the grids, and quickly obtain the location of the device;

[0016] S2. Add the time dimension on the basis of the geographic grid, and superimpose the predicted disasters and actual disasters, including typhoon paths, rainstorm information, etc., on the geographic grid;

[0017] S3. Model the disaster intensity and equipment anti-destruction capability within the small grid, predict the equipment failure probability within each small grid, and regard the equipment with a failure probability greater than a certain threshold as a faulty equipment;

[0018] S4. Further correction is made based on human statistics or drone photography information to obtain the final communication system failure information.

[0019] Further, preferably, the LoRa modulation parameters are correlated with the spreading factor, the coding rate and the bandwidth.

[0020] Further, preferably, the LoRa narrowband wireless ad hoc network technology adopts MAC layer routing technology and FSR routing protocol.

[0021] Furthermore, preferably, the power side of the coordinated recovery strategy of the power and communication systems of the distribution network aims at short repair time and small power outage losses, and the communication side aims at high coverage and high accuracy of disaster loss statistics.

[0022] Compared with the prior art, the present invention provides a method for coordinating power and communication of distribution networks under extreme disasters, which has the following beneficial effects:

[0023] 1. The present invention can quickly restore the power distribution network and communication system after a disaster occurs by coordinating the restoration of the power distribution network and the communication system, shorten the power outage and communication interruption time, and improve the recovery speed of the overall system. At the same time, the research on the recovery strategy can formulate corresponding response plans for different extreme disaster scenarios, improve the robustness and reliability of the system, and reduce the impact of disasters on the system. The power distribution network and communication system can also be restored in a short time during the disaster, which can reduce the losses of enterprises and users caused by power outages and communication failures and protect the continuity of production and business.

[0024] 2. By improving the robustness of terminal communications, the present invention can enable terminal equipment to maintain reliable communication capabilities under extreme disasters, ensure the transmission and communication of emergency information, provide timely information transmission, assist in disaster rescue work, optimize emergency response mechanisms, improve disaster resistance, ensure normal communication between users and the outside world, and improve user experience and satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application.

[0026] Figure 1 A flow chart of a method for coordinating power and communication in a distribution network under extreme disasters;

[0027] Figure 2 A schematic diagram of the power layer structure of the distribution network power-communication system structure in a distribution network power and communication coordination method under extreme disasters;

[0028] Figure 3 A schematic diagram of the communication layer structure of the distribution network power-communication system structure in a distribution network power and communication coordination method under extreme disasters;

[0029] Figure 4 A schematic diagram of a disaster chain of a power distribution network and communication coordination method under extreme disasters;

[0030] Figure 5 A schematic diagram of the ice-dancing disaster chain in a power and communication coordination method for distribution networks under extreme disasters;

[0031] Figure 6 A schematic diagram of a typhoon-rainstorm disaster in a method of coordination between power and communication in a distribution network under extreme disasters;

[0032] Figure 7 A schematic diagram of optical fiber communication topology of a distribution network in a method for coordinating power and communication in a distribution network under extreme disasters;

[0033] Figure 8A schematic diagram of the mechanism of power failure caused by disasters in a power and communication coordination method for distribution networks under extreme disasters;

[0034] Fig. 9 A schematic diagram of load curves of the power system and the communication system in a method for coordinating power and communication in a distribution network under extreme disasters;

[0035] Fig.10 A schematic diagram of a two-layer clustered structure of a distribution network communication system in a method for coordinating power and communication in distribution networks under extreme disasters;

[0036] Fig.11 A schematic diagram of grid division for distribution network communication failure in a method for coordinating power and communication in distribution network under extreme disasters;

[0037] Fig.12 A schematic diagram of superimposed disaster information of a distribution network communication failure in a distribution network power and communication coordination method under extreme disasters;

[0038] Fig.13 A schematic diagram of predicting fault location and correcting fault information in a power and communication coordination method for a distribution network under extreme disasters;

[0039] Fig.14 A schematic diagram of a distribution network communication network recovery model in a distribution network power and communication coordination method under extreme disasters;

[0040] Fig.15 A schematic diagram of the expansion mechanism of the spreading factor in a power and communication coordination method for distribution networks under extreme disasters;

[0041] Fig.16 A schematic diagram showing the effect of spreading factor on data rate under different bandwidths in a power and communication coordination method for distribution networks under extreme disasters;

[0042] Fig.17 A schematic diagram of the MAC routing principle framework in a power and communication coordination method for distribution networks under extreme disasters;

[0043] Fig.18 A schematic diagram of the division of fisheye domain in a method for coordinating power and communication in a distribution network under extreme disasters;

[0044] Fig.19 A schematic diagram of improving the robustness of intelligent terminal communication in a power and communication coordination method for distribution networks under extreme disasters;

[0045] Fig. 20 A schematic diagram of coordinated recovery analysis of power and communication systems in a distribution network power and communication coordination method under extreme disasters;

[0046] Fig.21A schematic diagram of a distribution network fault in a method for coordinating power and communication in a distribution network under extreme disasters; DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of this application, unless otherwise specified, "plurality" means two or more.

[0049] See also Figure 1-Figure 21 The embodiment of the present invention provides a method for coordinating power and communication of a distribution network under extreme disasters, which comprises the following steps:

[0050] S1. Analyze the ways and mechanisms of distribution network system failures caused by extreme disasters, and build a distribution network power-communication system structure model;

[0051] S2. Select a variety of emergency repair methods according to the actual needs of the site and determine the communication system recovery strategy based on the mobile self-organizing system architecture;

[0052] S3, using LoRa-based narrowband wireless ad hoc networking technology to improve the robustness of the STU communication module;

[0053] S4. Based on the mutual conversion relationship between distribution network communication restoration and power fault restoration, formulate a coordinated restoration strategy for distribution network power and communication systems under extreme disasters.

[0054] Based on the above technical solution, Figure 4-Figure 8 As shown, the ways and mechanisms of power and communication failures in distribution networks caused by extreme disasters such as typhoons, heavy rains, ice and snow are roughly the same. The most common ones are consecutive failures caused by tower collapse and line breakage. The causes of power failures may also include electrical failures caused by indirect damage such as wind deflection flashover and foreign objects hanging on the lines.

[0055] Generally speaking, the passage of a typhoon will cause a large number of distribution network towers to collapse. Whether the towers collapse depends on factors such as wind force, wind direction, tower design strength, tower materials, tower structure, and geographical location. Among them, the main reason for the collapse of towers is that the maximum wind speed exceeds the wind resistance standard of the tower design. Its manifestations can be divided into the vertical wind load of the tower and its connecting wires exceeding the maximum bearing capacity of the tower and the tower bending caused by the disparity in lateral horizontal forces on both sides of the tower along the line direction; for towers with weak tower bases, when the anti-overturning capacity cannot meet the extremely strong wind force, there will be different degrees of pulling up or sinking, which will cause the tower to collapse as a whole. Typhoons are often accompanied by heavy rains, and rainwater washes or soaks the tower foundation, causing damage to the tower foundation. Typhoons may even cause secondary disasters such as floods, landslides, and mudslides, all of which can further cause damage to towers.

[0056] Line breakage is one of the main manifestations of power and communication failures in distribution networks caused by typhoons. The main reason is that the wind load perpendicular to the line exceeds the design standard of the line.

[0057] In addition to tower collapse and line disconnection similar to power failures, the damage to communication system functions may also be caused by sudden reduction in communication node capacity due to extreme disasters, resulting in node damage. There are two main reasons for communication network topology failures caused by extreme disasters: line failure and node failure. Line failures appear at the physical layer as cut optical cables. The failure of a single line at the upper layer may appear as the failure of multiple logical line connections at the lower layer. Node failures appear as the failure of network switching nodes, and the failure of upstream nodes appears as the failure of all downstream nodes. Figure 8 As shown in the figure, once the optical fiber 4-5 is broken, the communication of its downstream line will inevitably be interrupted without other communication methods. If node 4 fails, its downstream nodes 5 and 6 will inevitably lose communication. Whether a node can communicate normally can be represented by connectivity. Connectivity refers to the sum of communication paths established between a single communication node and the command center. The greater the connectivity, the more secure the communication. When the node connectivity is 0, the node loses its communication function.

[0058] Due to the extremely destructive power of extreme disasters, the power system and communication system of the distribution network are both damaged on a large scale. The traditional distribution network resilience assessment method has not yet taken into account the impact of communication system failure. On the one hand, the current research on distribution network resilience is mostly based on the fact that distribution network information is fully accessible. Once an extreme disaster causes a failure in the distribution network communication system, the commander may not be able to obtain distribution network status information in a timely manner. When restoring the distribution network system, the damage to the communication system greatly affects the monitoring and control of the distribution network system, resulting in a decrease in the level of dispatching automation, which in turn affects the assessment of distribution network resilience. On the other hand, with the development of information and communication technology, the traditional distribution network has gradually evolved into a distribution network information-physical fusion system with deep integration of information and power. The impact of the communication system on power is becoming increasingly profound. Therefore, it is necessary to re-examine the distribution network resilience from the perspective of information physics.

[0059] like Fig. 9 As shown in the figure, after an extreme disaster, based on the physical state information of the distribution network, without considering communication failures, considering the optimization goals such as the grid reconstruction of the distribution network and post-disaster fault repair, the load change curve A of the regional distribution network is obtained; assuming that when the communication system fails, the recovery of the distribution network cannot be completed according to the established goals, the load change curve B of the distribution network is obtained; the area enclosed by the load curve A and F(t)=F0 is the resilience of the distribution network under traditional conditions, and the area enclosed by the load curve B and F(t)=F0 is defined as the resilience of the distribution network when the communication system fails under extreme disasters, and the area enclosed by curve A and curve B is defined as the impact of the communication system on the resilience of the distribution network under extreme disasters.

[0060] When a large-scale failure occurs in the communication system, it greatly hinders the recovery of the distribution network, especially when communication failure occurs between the distribution network interconnection lines and the load in the non-faulty section cannot be quickly restored through grid reconstruction.

[0061] Based on the above technical solutions, the main features of mobile self-organization are self-organization, centerless, multi-hop communication and limited bandwidth. Using the characteristics of mobile self-organization to repair the distribution network communication network has the following advantages:

[0062] a. Communication nodes in disaster situations can form their own network and do not need to be repaired according to the original network;

[0063] b. There is no absolute central node in the distribution network communication network, and the repair path can be adjusted at any time during the repair process;

[0064] c. When there are obstacles in the path between nodes, a third node can be used to achieve communication through multi-hop communication.

[0065] Therefore, on the one hand, by coordinating the restoration of the power and communication systems of the distribution network, the power and communication systems of the distribution network can be quickly restored after a disaster occurs, shortening the time of power outages and communication interruptions, and improving the recovery speed of the overall system. At the same time, the research on recovery strategies can formulate corresponding response plans for different extreme disaster scenarios, improve the robustness and reliability of the system, and reduce the impact of disasters on the system. The power and communication systems of the distribution network can also be restored in a short time during the disaster, which can reduce the losses of enterprises and users caused by power outages and communication failures and protect the continuity of production and business; on the other hand, by improving the robustness of terminal communications, terminal equipment can still maintain reliable communication capabilities under extreme disasters, ensuring the transmission and communication of emergency information, and can also provide timely information transmission, assist in disaster relief work, optimize emergency response mechanisms, improve disaster resistance, ensure normal communication between users and the outside world, and improve user experience and satisfaction.

[0066] In a possible implementation manner, the distribution network system fault includes a power system fault and a communication system fault.

[0067] In a possible implementation, the emergency repair method includes but is not limited to using optical fiber emergency repair, mobile base station emergency repair and emergency communication vehicle.

[0068] It needs to be explained that the recovery method of the distribution network communication network after a disaster is mainly through optical fiber repair. Its advantage is that the communication nodes repaired through optical fiber can safely transmit control signals and are not easily interfered by external factors. In addition, wireless communication of distribution network nodes can be achieved through mobile base stations and emergency communication vehicles. A single mobile base station can cover multiple distribution network communication nodes. This method shortens the recovery time of the communication system, which is beneficial to the disaster awareness of the distribution network after extreme disasters, and then speeds up the repair of electricity. The emergency communication vehicle is equivalent to a constantly moving base station. After completing the emergency communication in a certain area, it moves to the communication intermediate node in the next area.

[0069] In a possible implementation manner, the mobile self-organizing system architecture is a two-layer cluster structure, wherein the upper layer nodes are only connected to the cluster head node, and the nodes within the cluster communicate with the upper layer nodes through the cluster head node.

[0070] In a possible implementation manner, the communication system recovery strategy of the mobile self-organizing architecture includes the following steps:

[0071] S1. Use the space-time grid fusion method, add pre-disaster prediction, divide the disaster-stricken area into small grids, encode the grids, and quickly obtain the location of the device;

[0072] S2. Add the time dimension on the basis of the geographic grid, and superimpose the predicted disasters and actual disasters, including typhoon paths, rainstorm information, etc., on the geographic grid;

[0073] S3. Model the disaster intensity and equipment anti-destruction capability within the small grid, predict the equipment failure probability within each small grid, and regard the equipment with a failure probability greater than a certain threshold as a faulty equipment;

[0074] S4. Further correction is made based on human statistics or drone photography information to obtain the final communication system failure information.

[0075] It needs to be explained that in order to speed up the repair of the distribution network communication system after extreme disasters, the real-time positioning of the fault is required to be high. Due to communication failures, the efficiency of obtaining fault information is very low only through post-disaster analysis. For this reason, combined with the means of pre-disaster prediction, the fault location is completed according to the extreme disaster forecast information, and then the fault location is corrected through post-disaster human judgment. When predicting distribution network communication failures before extreme disasters, the communication network status is predicted by fusion of multi-source information such as geographic information, meteorological information, and communication grid structure information. The amount of multi-source information in the distribution network is huge and the distribution range is wide, and large-scale data processing is more difficult. Therefore, it is necessary to establish a communication system recovery strategy for the mobile self-organizing system architecture according to the above steps.

[0076] In a possible implementation, the LoRa modulation parameters are correlated with a spreading factor (SF), a coding rate (CR), and a bandwidth (BW).

[0077] Through the above technical solution, LoRa modulation adopts Chirp spread spectrum technology. Chirp spread spectrum refers to signal modulation by changing the frequency from low to high (or from high to low) within a symbol time. It has the characteristics of resistance to multipath fading and Doppler effect.

[0078] LoRa uses multiple orthogonal spreading factors (between 6 and 12). SF is a compromise between data rate and transmission distance. Selecting a higher spreading factor can increase the transmission distance, but it will reduce the data rate. On the contrary, a low spreading factor will reduce the transmission distance and increase the data rate. When the link environment is good, a lower spreading factor, that is, a higher data rate, can be used. When the link environment is poor, the sensitivity can be improved by increasing the spreading factor. Each symbol consists of a length of 2 SF The extension code is extended, and the extension mechanism is as follows Fig.15 At the transmitter, the spreading code is divided into two SF / SF code, then use 2 SF chips to spread a symbol. The spreading code is also known in the receiver. Replacing a symbol with multiple information chips means that the spreading factor has a direct impact on the effective data rate. Fig.16Shown is the relationship between the choice of SF and the data rate for bandwidths of 125kHz, 250kHz, and 500kHz. At the receiver, the spreading code is multiplied by the received bits to regenerate the input data.

[0079] LoRa uses forward error correction (FEC) to further improve the sensitivity of the receiver. The coding rate (or information rate) defines the amount of FEC. LoRa provides CR values ​​from 0 to 4, where CR 0 means that FEC is not used. The cyclic coding rate corresponding to CR 1, 2, 3, and 4 is the proportion of the useful part of the data stream. Using FEC will generate transmission overhead, so as the CR value increases, the cyclic coding rate is lower, and the effective data rate of each channel is reduced.

[0080] LoRa is a half-duplex system, with uplink and downlink operating in the same frequency band. Increasing the signal bandwidth can increase the data rate, but the receiving sensitivity will decrease. At present, the bandwidth of the LoRa system supported by a single chip in China is 2MHz, including 8 channels with a fixed bandwidth of 125kHz. A 125kHz protection band is required between each fixed bandwidth channel, so at least 2MHz system bandwidth is required. For a fixed bandwidth channel of 125kHz, the data rate can be selected within a fairly large range from 250bit / s to 5k bit / s.

[0081] In a possible implementation, the LoRa narrowband wireless ad hoc network technology adopts MAC layer routing technology and FSR routing protocol.

[0082] It should be explained that when receiving a data packet, the traditional IP routing technology first unpacks the data packet and then sends it to the network layer for the following processing: search the local routing table according to the destination IP address to see if there is a reachable route. If so, forward the data packet according to the route; otherwise, it is necessary to initiate a route search, send a request and return the route in a hop-by-hop manner, and finally establish an available path; in the subsequent data packet forwarding, each node must split the IP address from the data packet header to find the route, and the data packet must be transmitted to the routing layer before it can be processed. The whole process is very time-consuming, and in general, the IP header has a fixed length of 20 bytes, which brings considerable network overhead. For narrowband wireless channels based on LoRa, the IP header occupies a considerable part of the bandwidth, greatly reducing the throughput of the entire network, so MAC layer routing technology is required.

[0083] MAC layer routing means that the routing protocol works at the MAC layer and is integrated with the basic functions of the MAC layer (such as conflict detection and retransmission mechanism). The basic principle framework of MAC layer routing is as follows: Fig.17 shown.

[0084] Routing search is performed in MAC, so the data format is in MAC frame format, which is implemented based on MAC address. The data comes from the sensor nodes in the network. The box shows the entire process of data processing, and finally it is sent or received through the underlying communication interface. Data sending process: First, determine whether there is an available route for sending data. It can be implemented by using table-driven routing protocol or on-demand routing protocol. If it exists, the data frame is sent along the path. Otherwise, the data to be sent is inserted into the local sending message queue and the route discovery process is initiated. Data receiving process: First, determine whether the received data is a routing control information frame or a data frame. If it is routing information, it is used to update the temporary routing table. Otherwise, it proves to be a data frame. Determine whether the destination address is the local address. If so, receive the data and process it. Otherwise, find out whether there is a path to forward the data. If so, forward it. Otherwise, discard the data frame and send a routing error message. Implementing the routing function at the MAC layer can well avoid the route discovery delay caused by IP header encapsulation and decapsulation during IP routing, and greatly reduce the bandwidth consumption caused by address information during transmission. The protocol is simpler to implement, easy to operate and control, and is very suitable for narrowband wireless ad hoc networks based on LoRa.

[0085] When selecting routing technology, it is also necessary to develop a reasonable routing protocol to ensure the stability of communication. FSR (Fisheye State Routing) routing is a table-driven routing protocol that uses the "Fisheye Domain" technology. Fig.18 As shown in the figure, the fisheye domain refers to the node set after the nodes are divided into regions according to the distance from the node (measured by the number of hops). Nodes in different fisheye domains broadcast link state information at different frequencies, and the update frequency slows down as the distance from the node increases. Therefore, nodes within the domain will obtain accurate routing information, while the accuracy of the routing of nodes outside the domain becomes lower as the distance from the destination node increases. Moreover, in the FSR routing protocol, not all link state information is forwarded, but its records are distributed at different frequencies according to the fisheye domain where the node is located. The node records in the nearest fisheye domain are distributed to neighboring nodes at a high frequency, and other records use a low frequency, which greatly reduces the link state update information and reduces the network overhead. In a mobile network environment where the network topology changes dynamically, the routing information will become more accurate as the distance shortens, overcoming the impact of node movement on routing. When dealing with link collapse, FSR does not use any control information, but only deletes the relevant information in the topology table and neighbor table, avoiding excessive bandwidth occupation due to link collapse, which in turn affects the re-establishment of routing. FSR uses the destination sequence number to ensure that the link state information is always up to date and avoid loop routing. Based on the above characteristics, it can be concluded that FSR routing is more suitable for application in LoRa-based narrowband wireless network environments.

[0086] In a possible implementation, the coordinated recovery strategy of the power and communication systems of the distribution network aims at short repair time and small power outage losses on the power side, and aims at high coverage and high accuracy of disaster loss statistics on the communication side.

[0087] Based on the above technical solutions, after an extreme disaster occurs, when both the power failure and the communication system fail, such as Fig.21 As shown in the figure, it is a two-line grid structure, and line 5-8 is a reconstruction line. When the optical fiber communication is normal, the grid reconstruction can be quickly realized. Line 1-2, line 2-3, and line 5-6 have faults. When the optical fiber communication fails, nodes 2, 3, 4, 5, 6, and 9 are out of power. When the optical fiber communication system is not faulty, the grid reconstruction of line 5-8 can quickly realize the power restoration of nodes 3, 4, and 5. The power restoration of node 2 can only be achieved through the repair of line 1-2 or the restoration of line 2-3 after grid reconstruction, and the restoration of nodes 6 and 9 must be achieved through the restoration of line 5-6. If the grid reconstruction is unsuccessful, lines 1-2, 2-3, and 5-6 need to be repaired at the same time to realize the power restoration of nodes 6 and 9. Therefore, in this case, when the load importance is roughly the same, the ideal recovery order should be: optical fiber communication (line 5-8)-power failure (line 5-6)-power failure (line 1-2 or line 2-3, depending on the difficulty of recovery).

[0088] In this scheme, it is not considered that the fault status can be obtained by the command center. Assuming that the mobile communication network in the area is destroyed, the upper-level decision-makers cannot understand the disaster situation in the area in real time. They can only know that nodes 2, 3, 4, 5, 6, and 9 have power outages through the power meter information. Due to the failure of the upstream node, the downstream node will also be out of power, but they do not know the specific damage of the line. Assuming that line 3-4 and line 4-5 are also faulty, then the restoration of optical fiber communication (line 5-8) at this time is meaningless and will delay the repair time. But in fact, line 3-4 and line 4-5 are not faulty, and the power supply of nodes 3, 4, and 5 can be restored through the restoration of optical fiber communication (line 5-8). Through this assumption, it can be seen that when all the lines in the power outage area are faulty, it is not meaningful to restore the mobile communication network. At this time, it can be restored from the upstream line to the downstream line in sequence; but when the downstream line has fewer faults and can be quickly restored through grid reconstruction, the role of communication system restoration is huge.

[0089] In order to improve the efficiency and speed of distribution network restoration after extreme disasters, the mutual influence between power restoration and communication restoration is taken into account: before the power fault is restored, the relevant emergency repair on the communication side can not only restore the distribution network interconnection switch to normal and quickly restore the load in the non-fault area of ​​the distribution network, but also enable the power fault in the disaster area to be accurately monitored and guide the smooth progress of post-disaster power repair work; however, if the emergency repair on the communication side of the distribution network is all carried out before the power side, it will inevitably cause a serious lag in the emergency repair on the power side, which is not in line with the principles of the power company's emergency repair guidance plan after the actual disaster.

[0090] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for coordinating power and communication in a distribution network under extreme disasters, characterized in that: The following steps are involved: S1. Analyze the ways and mechanisms of distribution network system failures caused by extreme disasters, and build a distribution network power-communication system structure model; S2. Select a variety of emergency repair methods according to the actual needs of the site and determine the communication system recovery strategy based on the mobile self-organizing system architecture; S3, using LoRa-based narrowband wireless ad hoc networking technology to improve the robustness of the STU communication module; S4. Based on the mutual conversion relationship between distribution network communication restoration and power fault restoration, formulate a coordinated restoration strategy for distribution network power and communication systems under extreme disasters.

2. The method for coordinating power and communication of a distribution network under extreme disasters according to claim 1 is characterized in that: The distribution network system failure includes a power system failure and a communication system failure.

3. The method for coordinating power and communication of a distribution network under extreme disasters according to claim 1 is characterized in that: The emergency repair methods include but are not limited to the use of optical fiber emergency repair, mobile base station emergency repair and emergency communication vehicles.

4. The method for coordinating power and communication of a distribution network under extreme disasters according to claim 1 is characterized in that: The mobile self-organizing system structure is a two-layer cluster structure, wherein the upper layer nodes are only connected to the cluster head node, and the nodes in the cluster communicate with the upper layer nodes through the cluster head node.

5. The method for coordinating power and communication of a distribution network under extreme disasters according to claim 1 is characterized in that: The communication system recovery strategy of the mobile self-organizing architecture includes the following steps: S1. Use the space-time grid fusion method, add pre-disaster prediction, divide the disaster-stricken area into small grids, encode the grids, and quickly obtain the location of the device; S2. Add the time dimension on the basis of the geographic grid, and superimpose the predicted disasters and actual disasters, including typhoon paths, rainstorm information, etc., on the geographic grid; S3. Model the disaster intensity and equipment anti-destruction capability within the small grid, predict the equipment failure probability within each small grid, and regard the equipment with a failure probability greater than a certain threshold as a faulty equipment; S4. Further correction is made based on human statistics or drone photography information to obtain the final communication system failure information.

6. The method for coordinating power and communication of a distribution network under extreme disasters according to claim 1 is characterized in that: The LoRa modulation parameters are correlated with the spreading factor, coding rate and bandwidth.

7. The method for coordinating power and communication of a distribution network under extreme disasters according to claim 4 is characterized in that: The narrowband wireless ad hoc network technology of LoRa adopts MAC layer routing technology and FSR routing protocol.

8. The method for coordinating power and communication of a distribution network under extreme disasters according to claim 1 is characterized in that: The coordinated recovery strategy of the power and communication systems of the distribution network aims at short repair time and small power outage losses on the power side, and aims at high coverage and high accuracy of disaster loss statistics on the communication side.

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